1
|
Walker IS, Rogerson SJ. Pathogenicity and virulence of malaria: Sticky problems and tricky solutions. Virulence 2023; 14:2150456. [PMID: 36419237 PMCID: PMC9815252 DOI: 10.1080/21505594.2022.2150456] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/25/2022] Open
Abstract
Infections with Plasmodium falciparum and Plasmodium vivax cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection. In this article, we review the latest developments in the immunogenicity and pathogenesis of malaria, with a particular focus on P. falciparum, the leading malaria killer. Pathogenic factors include parasite-derived toxins and variant surface antigens on infected erythrocytes that mediate sequestration in the deep vasculature. Host response to parasite toxins and to variant antigens is an important determinant of disease severity. Understanding how parasites sequester, and how antibody to variant antigens could prevent sequestration, may lead to new approaches to treat and prevent disease. Difficulties in malaria diagnosis, drug resistance, and specific challenges of treating P. vivax pose challenges to malaria elimination, but vaccines and other preventive strategies may offer improved disease control.
Collapse
Affiliation(s)
- Isobel S Walker
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| | - Stephen J Rogerson
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| |
Collapse
|
2
|
Abo YN, Jamrozik E, McCarthy JS, Roestenberg M, Steer AC, Osowicki J. Strategic and scientific contributions of human challenge trials for vaccine development: facts versus fantasy. THE LANCET. INFECTIOUS DISEASES 2023; 23:e533-e546. [PMID: 37573871 DOI: 10.1016/s1473-3099(23)00294-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 08/15/2023]
Abstract
The unprecedented speed of delivery of SARS-CoV-2 pandemic vaccines has redefined the limits for all vaccine development. Beyond the aspirational 100-day timeline for tomorrow's hypothetical pandemic vaccines, there is a sense of optimism that development of other high priority vaccines can be accelerated. Early in the COVID-19 pandemic, an intense and polarised academic and public discourse arose concerning the role of human challenge trials for vaccine development. A case was made for human challenge trials as a powerful tool to establish early proof-of-concept of vaccine efficacy in humans, inform vaccine down selection, and address crucial knowledge gaps regarding transmission, pathogenesis, and immune protection. We review the track record of human challenge trials contributing to the development of vaccines for 19 different pathogens and discuss relevant limitations, barriers, and pitfalls. This Review also highlights opportunities for efforts to broaden the scope and boost the effects of human challenge trials, to accelerate all vaccine development.
Collapse
Affiliation(s)
- Yara-Natalie Abo
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia.
| | - Euzebiusz Jamrozik
- Ethox and Pandemic Sciences Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK; Monash-WHO Collaborating Centre for Bioethics, Monash University, Melbourne, VIC, Australia
| | - James S McCarthy
- Department of Infectious Diseases, The University of Melbourne, Parkville, VIC, Australia; Victorian Infectious Diseases Services, Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Meta Roestenberg
- Controlled Human Infections Center, Leiden University Medical Center, Leiden, Netherlands
| | - Andrew C Steer
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
| | - Joshua Osowicki
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
| |
Collapse
|
3
|
Ouédraogo A, Bougouma EC, Palacpac NMQ, Houard S, Nebie I, Sawadogo J, Berges GD, Soulama I, Diarra A, Hien D, Ouedraogo AZ, Konaté AT, Kouanda S, Myoui A, Ezoe S, Ishii KJ, Sato T, D’Alessio F, Leroy O, Tiono AB, Cousens S, Horii T, Sirima SB. Safety and immunogenicity of BK-SE36/CpG malaria vaccine in healthy Burkinabe adults and children: a phase 1b randomised, controlled, double-blinded, age de-escalation trial. Front Immunol 2023; 14:1267372. [PMID: 37908361 PMCID: PMC10613650 DOI: 10.3389/fimmu.2023.1267372] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
Background BK-SE36/CpG is a recombinant blood-stage malaria vaccine candidate based on the N-terminal Plasmodium falciparum serine repeat antigen5 (SE36), adsorbed to aluminium hydroxide gel and reconstituted, prior to administration, with synthetic oligodeoxynucleotides bearing CpG motifs. In healthy Japanese adult males, BK-SE36/CpG was well tolerated. This study assessed its safety and immunogenicity in healthy malaria-exposed African adults and children. Methods A double-blind, randomised, controlled, age de-escalating clinical trial was conducted in an urban area of Ouagadougou, Burkina Faso. Healthy participants (n=135) aged 21-45 years (Cohort 1), 5-10 years (Cohort 2) and 12-24 months (Cohort 3) were randomised to receive three vaccine doses (Day 0, 28 and 112) of BK-SE36/CpG or rabies vaccine by intramuscular injection. Results One hundred thirty-four of 135 (99.2%) subjects received all three scheduled vaccine doses. Vaccinations were well tolerated with no related Grade 3 (severe) adverse events (AEs). Pain/limitation of limb movement, headache in adults and fever in younger children (all mild to moderate in intensity) were the most frequently observed local and systemic AEs. Eighty-three of BK-SE36/CpG (91%) recipients and 37 of control subjects (84%) had Grade 1/2 events within 28 days post vaccination. Events considered by the investigator to be vaccine related were experienced by 38% and 14% of subjects in BK-SE36/CpG and control arms, respectively. Throughout the trial, six Grade 3 events (in 4 subjects), not related to vaccination, were recorded in the BK-SE36/CpG arm: 5 events (in 3 subjects) within 28 days of vaccination. All serious adverse events (SAEs) (n=5) were due to severe malaria (52-226 days post vaccination) and not related to vaccination. In all cohorts, BK-SE36/CpG arm had higher antibody titres after Dose 3 than after Dose 2. Younger cohorts had stronger immune responses (12-24-month-old > 5-10 years-old > 21-45 years-old). Sera predominantly reacted to peptides that lie in intrinsically unstructured regions of SE36. In the control arm, there were no marked fold changes in antibody titres and participants' sera reacted poorly to all peptides spanning SE36. Conclusion BK-SE36/CpG was well-tolerated and immunogenic. These results pave the way for further proof-of-concept studies to demonstrate vaccine efficacy. Clinical trial registration https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1921, PACTR201701001921166.
Collapse
Affiliation(s)
| | | | - Nirianne Marie Q. Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Sophie Houard
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Issa Nebie
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Jean Sawadogo
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | | | - Issiaka Soulama
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Denise Hien
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | | | - Amadou T. Konaté
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Seni Kouanda
- Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso
| | - Akira Myoui
- Medical Center for Translational Research, Osaka University Hospital, Suita, Japan
| | - Sachiko Ezoe
- Medical Center for Translational Research, Osaka University Hospital, Suita, Japan
- Department of Space Infection Control, Graduate School of Medicine, Division of Health Sciences, Osaka University, Osaka, Japan
| | - Ken J. Ishii
- Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Japan
- Laboratory of Vaccine Science, Immunology Frontier Research Center, Osaka University, Suita, Japan
- Division of Vaccine Science, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Takanobu Sato
- Research and Development Division, Nobelpharma Co., Ltd., Tokyo, Japan
| | - Flavia D’Alessio
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Odile Leroy
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Alfred B. Tiono
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Simon Cousens
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | | |
Collapse
|
4
|
Roobsoong W, Yadava A, Draper SJ, Minassian AM, Sattabongkot J. The challenges of Plasmodium vivax human malaria infection models for vaccine development. Front Immunol 2023; 13:1006954. [PMID: 36685545 PMCID: PMC9849360 DOI: 10.3389/fimmu.2022.1006954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 12/09/2022] [Indexed: 01/07/2023] Open
Abstract
Controlled Human Malaria Infection models (CHMI) have been critical to advancing new vaccines for malaria. Stringent and safe preparation of a challenge agent is key to the success of any CHMI. Difficulty producing the Plasmodium vivax parasite in vitro has limited production of qualified parasites for CHMI as well as the functional assays required to screen and down-select candidate vaccines for this globally distributed parasite. This and other challenges to P. vivax CHMI (PvCHMI), including scientific, logistical, and ethical obstacles, are common to P. vivax research conducted in both non-endemic and endemic countries, with additional hurdles unique to each. The challenges of using CHMI for P. vivax vaccine development and evaluation, lessons learned from previous and ongoing clinical trials, and the way forward to effectively perform PvCHMI to support vaccine development, are discussed.
Collapse
Affiliation(s)
- Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Anjali Yadava
- Biologics Research & Development, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Simon J. Draper
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | | | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| |
Collapse
|
5
|
Duffy PE. Current approaches to malaria vaccines. Curr Opin Microbiol 2022; 70:102227. [PMID: 36343566 PMCID: PMC11127243 DOI: 10.1016/j.mib.2022.102227] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/27/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022]
Abstract
The complex Plasmodium life cycle offers different vaccine approaches with distinct parasitological and clinical effects. The approaches and their rationales were established decades ago: vaccines targeting pre-erythrocytic (sporozoite and liver-stage) parasites prevent infection, those to blood-stage parasites reduce disease, and those to sexual-stage parasites or mosquito vector reduce transmission and eliminate malaria through herd immunity. The pre-erythrocytic RTS,S vaccine (Mosquirix, GlaskoSmithKline (GSK)), recommended by WHO in 2021, reduces clinical malaria in children. Knowledge of parasite biology, host-parasite interactions, and immune mechanisms is informing new concepts to improve on RTS,S and to target other parasite stages. This review emphasizes vaccine approaches and candidates currently in the clinic or likely to enter clinical testing soon.
Collapse
Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
6
|
Salkeld J, Themistocleous Y, Barrett JR, Mitton CH, Rawlinson TA, Payne RO, Hou MM, Khozoee B, Edwards NJ, Nielsen CM, Sandoval DM, Bach FA, Nahrendorf W, Ramon RL, Baker M, Ramos-Lopez F, Folegatti PM, Quinkert D, Ellis KJ, Poulton ID, Lawrie AM, Cho JS, Nugent FL, Spence PJ, Silk SE, Draper SJ, Minassian AM. Repeat controlled human malaria infection of healthy UK adults with blood-stage Plasmodium falciparum: Safety and parasite growth dynamics. Front Immunol 2022; 13:984323. [PMID: 36072606 PMCID: PMC9444061 DOI: 10.3389/fimmu.2022.984323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
In endemic settings it is known that natural malaria immunity is gradually acquired following repeated exposures. Here we sought to assess whether similar acquisition of blood-stage malaria immunity would occur following repeated parasite exposure by controlled human malaria infection (CHMI). We report the findings of repeat homologous blood-stage Plasmodium falciparum (3D7 clone) CHMI studies VAC063C (ClinicalTrials.gov NCT03906474) and VAC063 (ClinicalTrials.gov NCT02927145). In total, 24 healthy, unvaccinated, malaria-naïve UK adult participants underwent primary CHMI followed by drug treatment. Ten of these then underwent secondary CHMI in the same manner, and then six of these underwent a final tertiary CHMI. As with primary CHMI, malaria symptoms were common following secondary and tertiary infection, however, most resolved within a few days of treatment and there were no long term sequelae or serious adverse events related to CHMI. Despite detectable induction and boosting of anti-merozoite serum IgG antibody responses following each round of CHMI, there was no clear evidence of anti-parasite immunity (manifest as reduced parasite growth in vivo) conferred by repeated challenge with the homologous parasite in the majority of volunteers. However, three volunteers showed some variation in parasite growth dynamics in vivo following repeat CHMI that were either modest or short-lived. We also observed no major differences in clinical symptoms or laboratory markers of infection across the primary, secondary and tertiary challenges. However, there was a trend to more severe pyrexia after primary CHMI and the absence of a detectable transaminitis post-treatment following secondary and tertiary infection. We hypothesize that this could represent the initial induction of clinical immunity. Repeat homologous blood-stage CHMI is thus safe and provides a model with the potential to further the understanding of naturally acquired immunity to blood-stage infection in a highly controlled setting.
Collapse
Affiliation(s)
- Jo Salkeld
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Jordan R. Barrett
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Celia H. Mitton
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Ruth O. Payne
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Mimi M. Hou
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Baktash Khozoee
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Nick J. Edwards
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Carolyn M. Nielsen
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Diana Muñoz Sandoval
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Florian A. Bach
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Wiebke Nahrendorf
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Megan Baker
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | | | - Doris Quinkert
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Ian D. Poulton
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Alison M. Lawrie
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Jee-Sun Cho
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Fay L. Nugent
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Philip J. Spence
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Sarah E. Silk
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Simon J. Draper
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Angela M. Minassian
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
- *Correspondence: Angela M. Minassian,
| |
Collapse
|
7
|
Kibwana E, Kapulu M, Bejon P. Controlled Human Malaria Infection Studies in Africa-Past, Present, and Future. Curr Top Microbiol Immunol 2022. [PMID: 35704094 DOI: 10.1007/82_2022_256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Controlled human infection studies have contributed significantly to the understanding of pathogeneses and treatment of infectious diseases. In malaria, deliberately infecting humans with malaria parasites was used as a treatment for neurosyphilis in the early 1920s. More recently, controlled human malaria infection (CHMI) has become a valuable, cost-effective tool to fast-track the development and evaluation of new anti-malarial drugs and/or vaccines. CHMI studies have also been used to define host/parasite interactions and immunological correlates of protection. CHMI involves infecting a small number of healthy volunteers with malaria parasites, monitoring their parasitemia and providing anti-malarial treatment when a set threshold is reached. In this review we discuss the introduction, development, and challenges of modern-day Plasmodium falciparum CHMI studies conducted in Africa, and the impact of naturally acquired immunity on infectivity and vaccine efficacy. CHMIs have shown to be an invaluable tool particularly in accelerating malaria vaccine research. Although there are limitations of CHMI studies for estimating public health impacts and for regulatory purposes, their strength lies in proof-of-concept efficacy data at an early stage of development, providing a faster way to select vaccines for further development and providing valuable insights in understanding the mechanisms of immunity to malarial infection.
Collapse
Affiliation(s)
- Elizabeth Kibwana
- Bioscience Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
| | - Melissa Kapulu
- Bioscience Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Program, Kilifi, Kenya.
| |
Collapse
|
8
|
Rao VV, Godin CS, Lacy MJ, Inglefield JR, Park S, Blauth B, Reece JJ, Ionin B, Savransky V. Evaluation of the AV7909 Anthrax Vaccine Toxicity in Sprague Dawley Rats Following Three Intramuscular Administrations. Int J Toxicol 2021; 40:442-452. [PMID: 34281421 PMCID: PMC8532110 DOI: 10.1177/10915818211031239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AV7909 is a next-generation anthrax vaccine under development for post-exposure prophylaxis following suspected or confirmed Bacillus anthracis exposure, when administered in conjunction with the recommended antibacterial regimen. AV7909 consists of the FDA-approved BioThrax® vaccine (anthrax vaccine adsorbed) and an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide adjuvant, CPG 7909. The purpose of this study was to evaluate the potential systemic and local toxicity of AV7909 when administered via repeat intramuscular injection to the right thigh muscle (biceps femoris) to male and female Sprague Dawley rats. The vaccine was administered on Days 1, 15, and 29 and the animals were assessed for treatment-related effects followed by a 2-week recovery period to evaluate the persistence or reversibility of any toxic effects. The AV7909 vaccine produced no apparent systemic toxicity based on evaluation of clinical observations, body weights, body temperature, clinical pathology, and anatomic pathology. Necrosis and inflammation were observed at the injection sites as well as in regional lymph nodes and adjacent tissues and were consistent with immune stimulation. Antibodies against B. anthracis protective antigen (PA) were detected in rats treated with the AV7909 vaccine, confirming relevance of this animal model for the assessment of systemic toxicity of AV7909. In contrast, sera of rats that received saline or soluble CPG 7909 alone were negative for anti-PA antibodies. Overall, 3 intramuscular immunizations of Sprague Dawley rats with AV7909 were well tolerated, did not induce mortality or any systemic adverse effects, and did not result in any delayed toxicity.
Collapse
Affiliation(s)
| | | | | | - Jon R. Inglefield
- Frederick National Laboratory for Cancer Research, Frederick, MD (current affiliation; JRI was affiliated with the Emergent BioSolutions Inc, Gaithersburg, MD at the time of the work)
| | | | | | | | | | | |
Collapse
|
9
|
Bonam SR, Rénia L, Tadepalli G, Bayry J, Kumar HMS. Plasmodium falciparum Malaria Vaccines and Vaccine Adjuvants. Vaccines (Basel) 2021; 9:1072. [PMID: 34696180 PMCID: PMC8541031 DOI: 10.3390/vaccines9101072] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 12/02/2022] Open
Abstract
Malaria-a parasite vector-borne disease-is a global health problem, and Plasmodium falciparum has proven to be the deadliest among Plasmodium spp., which causes malaria in humans. Symptoms of the disease range from mild fever and shivering to hemolytic anemia and neurological dysfunctions. The spread of drug resistance and the absence of effective vaccines has made malaria disease an ever-emerging problem. Although progress has been made in understanding the host response to the parasite, various aspects of its biology in its mammalian host are still unclear. In this context, there is a pressing demand for the development of effective preventive and therapeutic strategies, including new drugs and novel adjuvanted vaccines that elicit protective immunity. The present article provides an overview of the current knowledge of anti-malarial immunity against P. falciparum and different options of vaccine candidates in development. A special emphasis has been made on the mechanism of action of clinically used vaccine adjuvants.
Collapse
Affiliation(s)
- Srinivasa Reddy Bonam
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, 8A Biomedical Grove, Singapore 138648, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Ganesh Tadepalli
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
| | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
- Biological Sciences & Engineering, Indian Institute of Technology Palakkad, Palakkad 678623, India
| | - Halmuthur Mahabalarao Sampath Kumar
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
| |
Collapse
|
10
|
Opi DH, Kurtovic L, Chan JA, Horton JL, Feng G, Beeson JG. Multi-functional antibody profiling for malaria vaccine development and evaluation. Expert Rev Vaccines 2021; 20:1257-1272. [PMID: 34530671 DOI: 10.1080/14760584.2021.1981864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for Plasmodium falciparum, a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials. AREAS COVERED In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite. We highlight the growing understanding of antibody effector functions against malaria and in vitro assays to measure these functional antibody responses. We discuss the application of these assays to quantify antibody functions in vaccine development and evaluation. EXPERT OPINION It is becoming increasingly clear that multiple antibody effector functions are involved in immunity to malaria. Therefore, we propose that evaluating vaccine candidates needs to move beyond individual assays or measuring IgG magnitude alone. Instead, vaccine evaluation should incorporate the full breadth of antibody response types and harness a wider range of assays measuring functional antibody responses. We propose a 3-tier approach to implementing assays to inform vaccine evaluation.
Collapse
Affiliation(s)
- D Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jessica L Horton
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia
| |
Collapse
|
11
|
Camponovo F, Lee TE, Russell JR, Burgert L, Gerardin J, Penny MA. Mechanistic within-host models of the asexual Plasmodium falciparum infection: a review and analytical assessment. Malar J 2021; 20:309. [PMID: 34246274 PMCID: PMC8272282 DOI: 10.1186/s12936-021-03813-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/11/2021] [Indexed: 12/03/2022] Open
Abstract
Background Malaria blood-stage infection length and intensity are important drivers of disease and transmission; however, the underlying mechanisms of parasite growth and the host’s immune response during infection remain largely unknown. Over the last 30 years, several mechanistic mathematical models of malaria parasite within-host dynamics have been published and used in malaria transmission models. Methods Mechanistic within-host models of parasite dynamics were identified through a review of published literature. For a subset of these, model code was reproduced and descriptive statistics compared between the models using fitted data. Through simulation and model analysis, key features of the models were compared, including assumptions on growth, immune response components, variant switching mechanisms, and inter-individual variability. Results The assessed within-host malaria models generally replicate infection dynamics in malaria-naïve individuals. However, there are substantial differences between the model dynamics after disease onset, and models do not always reproduce late infection parasitaemia data used for calibration of the within host infections. Models have attempted to capture the considerable variability in parasite dynamics between individuals by including stochastic parasite multiplication rates; variant switching dynamics leading to immune escape; variable effects of the host immune responses; or via probabilistic events. For models that capture realistic length of infections, model representations of innate immunity explain early peaks in infection density that cause clinical symptoms, and model representations of antibody immune responses control the length of infection. Models differed in their assumptions concerning variant switching dynamics, reflecting uncertainty in the underlying mechanisms of variant switching revealed by recent clinical data during early infection. Overall, given the scarce availability of the biological evidence there is limited support for complex models. Conclusions This study suggests that much of the inter-individual variability observed in clinical malaria infections has traditionally been attributed in models to random variability, rather than mechanistic disease dynamics. Thus, it is proposed that newly developed models should assume simple immune dynamics that minimally capture mechanistic understandings and avoid over-parameterization and large stochasticity which inaccurately represent unknown disease mechanisms. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03813-z.
Collapse
Affiliation(s)
- Flavia Camponovo
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Tamsin E Lee
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jonathan R Russell
- Institute of Disease Modeling, Bill & Melinda Gates Foundation, 500 5th Ave N, Seattle, WA, 98109, USA
| | - Lydia Burgert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jaline Gerardin
- Department of Preventive Medicine and Institute for Global Health, Northwestern University, Chicago, IL, USA
| | - Melissa A Penny
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| |
Collapse
|
12
|
Minassian AM, Silk SE, Barrett JR, Nielsen CM, Miura K, Diouf A, Loos C, Fallon JK, Michell AR, White MT, Edwards NJ, Poulton ID, Mitton CH, Payne RO, Marks M, Maxwell-Scott H, Querol-Rubiera A, Bisnauthsing K, Batra R, Ogrina T, Brendish NJ, Themistocleous Y, Rawlinson TA, Ellis KJ, Quinkert D, Baker M, Lopez Ramon R, Ramos Lopez F, Barfod L, Folegatti PM, Silman D, Datoo M, Taylor IJ, Jin J, Pulido D, Douglas AD, de Jongh WA, Smith R, Berrie E, Noe AR, Diggs CL, Soisson LA, Ashfield R, Faust SN, Goodman AL, Lawrie AM, Nugent FL, Alter G, Long CA, Draper SJ. Reduced blood-stage malaria growth and immune correlates in humans following RH5 vaccination. MED 2021; 2:701-719.e19. [PMID: 34223402 PMCID: PMC8240500 DOI: 10.1016/j.medj.2021.03.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/19/2021] [Accepted: 03/25/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND Development of an effective vaccine against the pathogenic blood-stage infection of human malaria has proved challenging, and no candidate vaccine has affected blood-stage parasitemia following controlled human malaria infection (CHMI) with blood-stage Plasmodium falciparum. METHODS We undertook a phase I/IIa clinical trial in healthy adults in the United Kingdom of the RH5.1 recombinant protein vaccine, targeting the P. falciparum reticulocyte-binding protein homolog 5 (RH5), formulated in AS01B adjuvant. We assessed safety, immunogenicity, and efficacy against blood-stage CHMI. Trial registered at ClinicalTrials.gov, NCT02927145. FINDINGS The RH5.1/AS01B formulation was administered using a range of RH5.1 protein vaccine doses (2, 10, and 50 μg) and was found to be safe and well tolerated. A regimen using a delayed and fractional third dose, in contrast to three doses given at monthly intervals, led to significantly improved antibody response longevity over ∼2 years of follow-up. Following primary and secondary CHMI of vaccinees with blood-stage P. falciparum, a significant reduction in parasite growth rate was observed, defining a milestone for the blood-stage malaria vaccine field. We show that growth inhibition activity measured in vitro using purified immunoglobulin G (IgG) antibody strongly correlates with in vivo reduction of the parasite growth rate and also identify other antibody feature sets by systems serology, including the plasma anti-RH5 IgA1 response, that are associated with challenge outcome. CONCLUSIONS Our data provide a new framework to guide rational design and delivery of next-generation vaccines to protect against malaria disease. FUNDING This study was supported by USAID, UK MRC, Wellcome Trust, NIAID, and the NIHR Oxford-BRC.
Collapse
Affiliation(s)
| | - Sarah E. Silk
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Carolin Loos
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Ashlin R. Michell
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Michael T. White
- Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Nick J. Edwards
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Ian D. Poulton
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Celia H. Mitton
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Ruth O. Payne
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Michael Marks
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Hector Maxwell-Scott
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Antonio Querol-Rubiera
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Karen Bisnauthsing
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Rahul Batra
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Tatiana Ogrina
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Nathan J. Brendish
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | | | | | | | - Doris Quinkert
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Megan Baker
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | | | - Lea Barfod
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Daniel Silman
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Mehreen Datoo
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Iona J. Taylor
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Jing Jin
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - David Pulido
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Willem A. de Jongh
- ExpreSion Biotechnologies, SCION-DTU Science Park, Agern Allé 1, Hørsholm 2970, Denmark
| | - Robert Smith
- Clinical BioManufacturing Facility, University of Oxford, Oxford OX3 7JT, UK
| | - Eleanor Berrie
- Clinical BioManufacturing Facility, University of Oxford, Oxford OX3 7JT, UK
| | | | | | | | | | - Saul N. Faust
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Anna L. Goodman
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | | | - Fay L. Nugent
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Galit Alter
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Simon J. Draper
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| |
Collapse
|
13
|
Vekemans J, Schellenberg D, Benns S, O'Brien K, Alonso P. Meeting report: WHO consultation on malaria vaccine development, Geneva, 15-16 July 2019. Vaccine 2021; 39:2907-2916. [PMID: 33931251 DOI: 10.1016/j.vaccine.2021.03.093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 01/25/2023]
Abstract
Considerable progress has been made in malaria control in the last two decades, but progress has stalled in the last few years. New tools are needed to achieve public health goals in malaria control and elimination. A first generation vaccine, RTS,S/AS01, is currently being evaluated as it undergoes pilot implementation through routine health systems in parts of three African countries. The development of this vaccine took over 30 years and has been full of uncertainties. Even now, important unknowns remain as to its future role in public health. Lessons need to be learnt for second generation and future vaccines, including how to facilitate early planning of investments, streamlining of development, regulatory and policy pathways. A number of candidate vaccines populate the current development pipeline, some of which have the potential to contribute to burden reduction if efficacy is confirmed in conditions of natural exposure, and if they are amenable to affordable supply and programmatic implementation. New, innovative technologies will be needed if future malaria vaccines are to overcome important scientific hurdles and induce durable, high level protection. WHO convened a stakeholder consultation on the status of malaria vaccine research and development to inform the recently reconstituted Malaria Vaccine Advisory Committee (MALVAC) which will assist WHO in updating its current guidance and recommendations about priorities and product preferences for malaria vaccines.
Collapse
Affiliation(s)
- Johan Vekemans
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | | | | | - Kate O'Brien
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | - Pedro Alonso
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| |
Collapse
|
14
|
Pirahmadi S, Zakeri S, Djadid ND, Mehrizi AA. A review of combination adjuvants for malaria vaccines: a promising approach for vaccine development. Int J Parasitol 2021; 51:699-717. [PMID: 33798560 DOI: 10.1016/j.ijpara.2021.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 12/18/2020] [Accepted: 01/28/2021] [Indexed: 01/16/2023]
Abstract
It is obvious that there is a critical need for an efficient malaria vaccine to accelerate malaria eradication. Currently, recombinant subunit vaccination against malaria using proteins and peptides is gaining attention. However, one of the major drawbacks of this approach is the lack of an efficient and durable immune response. Therefore, subunit vaccines require adjuvants to make the vaccine sufficiently immunogenic. Considering the history of the RTS,S vaccine, it seems likely that no single adjuvant is capable of eliciting all the protective immune responses required in many malarial subunit vaccines and the use of combination adjuvants will be increasingly important as the science of malaria vaccines advances. In light of this, it appears that identifying the most effective mixture of adjuvants with minimal adverse effects offers tremendous opportunities in improving the efficacy of vaccines against malaria. Owing to the importance of a multi-adjuvanted approach in subunit malaria vaccine development, this review paper outlines some of the best known combination adjuvants used in malaria subunit vaccines, focusing on their proposed mechanisms of action, their immunological properties, and their notable results. The aim of the present review is to consolidate these findings to aid the application of these combination adjuvants in experimental malaria vaccines.
Collapse
Affiliation(s)
- Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Navid D Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Akram A Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| |
Collapse
|
15
|
Wockner LF, Hoffmann I, Webb L, Mordmüller B, Murphy SC, Kublin JG, O'Rourke P, McCarthy JS, Marquart L. Growth Rate of Plasmodium falciparum: Analysis of Parasite Growth Data From Malaria Volunteer Infection Studies. J Infect Dis 2020; 221:963-972. [PMID: 31679015 PMCID: PMC7198127 DOI: 10.1093/infdis/jiz557] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022] Open
Abstract
Background Growth rate of malaria parasites in the blood of infected subjects is an important
measure of efficacy of drugs and vaccines. Methods We used log-linear and sine-wave models to estimate the parasite growth rate of the 3D7
strain of Plasmodium falciparum using data from 177 subjects from 14
induced blood stage malaria (IBSM) studies conducted at QIMR Berghofer. We estimated
parasite multiplication rate per 48 hour (PMR48), PMR per life-cycle
(PMRLC), and parasite life-cycle duration. We compared these parameters to
those from studies conducted elsewhere with infections induced by IBSM (n=66),
sporozoites via mosquito bite (n=336) or injection (n=51). Results The parasite growth rate of 3D7 in QIMR Berghofer studies was 0.75/day (95% CI:
0.73–0.77/day), PMR48 was 31.9 (95% CI: 28.7–35.4),
PMRLC was 16.4 (95% CI: 15.1–17.8) and parasite life-cycle was 38.8
hour (95% CI: 38.3–39.2 hour). These parameters were similar to estimates from
IBSM studies elsewhere (0.71/day, 95% CI: 0.67–0.75/day; PMR48 26.6,
95% CI: 22.2–31.8), but significantly higher (P < 0.001)
than in sporozoite studies (0.47/day, 95% CI: 0.43–0.50/day; PMR48
8.6, 95% CI: 7.3–10.1). Conclusions Parasite growth rates were similar across different IBSM studies and higher than
infections induced by sporozoite.
Collapse
Affiliation(s)
- Leesa F Wockner
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Isabell Hoffmann
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | - Sean C Murphy
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, Washington, USA
| | - James G Kublin
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| |
Collapse
|
16
|
Bliss' and Loewe's additive and synergistic effects in Plasmodium falciparum growth inhibition by AMA1-RON2L, RH5, RIPR and CyRPA antibody combinations. Sci Rep 2020; 10:11802. [PMID: 32678144 PMCID: PMC7366652 DOI: 10.1038/s41598-020-67877-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/15/2020] [Indexed: 01/10/2023] Open
Abstract
Plasmodium invasion of red blood cells involves malaria proteins, such as reticulocyte-binding protein homolog 5 (RH5), RH5 interacting protein (RIPR), cysteine-rich protective antigen (CyRPA), apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2), all of which are blood-stage malaria vaccine candidates. So far, vaccines containing AMA1 alone have been unsuccessful in clinical trials. However, immunization with AMA1 bound with RON2L (AMA1-RON2L) induces better protection against P. falciparum malaria in Aotus monkeys. We therefore sought to determine whether combinations of RH5, RIPR, CyRPA and AMA1-RON2L antibodies improve their biological activities and sought to develop a robust method for determination of synergy or additivity in antibody combinations. Rabbit antibodies against AMA1-RON2L, RH5, RIPR or CyRPA were tested either alone or in combinations in P. falciparum growth inhibition assay to determine Bliss' and Loewe's additivities. The AMA1-RON2L/RH5 combination consistently demonstrated an additive effect while the CyRPA/RIPR combination showed a modest synergistic effect with Hewlett’s \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$S=1.07 \left[95\% \mathrm{C}\mathrm{I}: 1.03, 1.19\right].$$\end{document}S=1.0795%CI:1.03,1.19. Additionally, we provide a publicly-available, online tool to aid researchers in analyzing and planning their own synergy experiments. This study supports future blood-stage vaccine development by providing a solid methodology to evaluate additive and/or synergistic (or antagonistic) effect of vaccine-induced antibodies.
Collapse
|
17
|
Savransky V, Lacy M, Ionin B, Skiadopoulos MH, Shearer J. Repeat-Dose Toxicity Study of a Lyophilized Recombinant Protective Antigen-Based Anthrax Vaccine Adjuvanted With CpG 7909. Int J Toxicol 2020; 38:163-172. [PMID: 31179828 DOI: 10.1177/1091581819848722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A recombinant protective antigen (rPA) anthrax vaccine candidate (rPA7909) was developed as a next-generation vaccine indicated for postexposure prophylaxis of disease resulting from suspected or confirmed Bacillus anthracis exposure. The lyophilized form of rPA7909-vaccinated candidate contains 75 µg purified rPA, 750 µg aluminum (as Alhydrogel adjuvant), and 250 µg of an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide CpG 7909 in a 0.5 mL phosphate-buffered suspension. General toxicity and local reactogenicity were evaluated in Sprague Dawley rats vaccinated with the full human dose of rPA7909 by intramuscular injection. Animals were immunized on study days 1, 15, and 29. Control groups were administered diluent only or adjuvant control (excipients, CpG 7909, and Alhydrogel adjuvant in diluent) intramuscularly at the same dose volume and according to the same schedule used for rPA7909. Toxicity was assessed based on the results of clinical observations, physical examinations, body weights, injection site reactogenicity, ophthalmology, clinical pathology (hematology, coagulation, and serum chemistry), organ weights, and macroscopic and microscopic pathology evaluation. The immune response to rPA7909 vaccination was confirmed by measuring serum anti-PA immunoglobulin G levels. The rPA7909 vaccine produced no apparent systemic toxicity and only transient reactogenicity at the injection site. The injection site reaction from animals receiving the adjuvant control was very similar to those receiving rPA7909 with respect to the inflammation. The inflammatory response observed in the injection site and the draining lymph nodes was consistent with expected immune stimulation. The overall results indicated a favorable safety profile for rPA7909.
Collapse
Affiliation(s)
| | - Michael Lacy
- 1 Emergent BioSolutions Inc, Gaithersburg, MD, USA
| | - Boris Ionin
- 1 Emergent BioSolutions Inc, Gaithersburg, MD, USA
| | | | | |
Collapse
|
18
|
Atmar RL, Keitel WA. Searching for Improved Flu Vaccines-The Time Is Now. J Infect Dis 2020; 221:1-4. [PMID: 31665360 DOI: 10.1093/infdis/jiz545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 12/21/2022] Open
Affiliation(s)
- Robert L Atmar
- Departments of Medicine and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Wendy A Keitel
- Departments of Medicine and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
19
|
Comberlato A, Paloja K, Bastings MMC. Nucleic acids presenting polymer nanomaterials as vaccine adjuvants. J Mater Chem B 2019; 7:6321-6346. [PMID: 31460563 DOI: 10.1039/c9tb01222b] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Most vaccines developed today include only the antigens that best stimulate the immune system rather than the entire virus or microbe, which makes vaccine production and use safer and easier, though they lack potency to induce acceptable immunity and long-term protection. The incorporation of additional immune stimulating components, named adjuvants, is required to generate a strong protective immune response. Nucleic acids (DNA and RNA) and their synthetic analogs are promising candidates as vaccine adjuvants activating Toll-like receptors (TLRs). Additionally, in the last few years several nanocarriers have emerged as platforms for targeted co-delivery of antigens and adjuvants. In this review, we focus on the recent developments in polymer nanomaterials presenting nucleic acids as vaccine adjuvants. We aim to compare the effectiveness of the various classes of polymers in immune modulating materials (nanoparticles, dendrimers, single-chain particles, nanogels, polymersomes and DNA-based architectures). In particular, we address the critical role of parameters such as size, shape, complexation and release of TLR ligands, cellular uptake, stability, toxicity and potential importance of spatial control in ligand presentation.
Collapse
Affiliation(s)
- Alice Comberlato
- IMX/IBI, EPFL, EPFL-STI-IMX-PBL MXC 340 Station 12, Lausanne, 1015, Switzerland.
| | - Kaltrina Paloja
- IMX/IBI, EPFL, EPFL-STI-IMX-PBL MXC 340 Station 12, Lausanne, 1015, Switzerland.
| | - Maartje M C Bastings
- IMX/IBI, EPFL, EPFL-STI-IMX-PBL MXC 340 Station 12, Lausanne, 1015, Switzerland.
| |
Collapse
|
20
|
Khoury DS, Aogo R, Randriafanomezantsoa-Radohery G, McCaw JM, Simpson JA, McCarthy JS, Haque A, Cromer D, Davenport MP. Within-host modeling of blood-stage malaria. Immunol Rev 2019; 285:168-193. [PMID: 30129195 DOI: 10.1111/imr.12697] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Malaria infection continues to be a major health problem worldwide and drug resistance in the major human parasite species, Plasmodium falciparum, is increasing in South East Asia. Control measures including novel drugs and vaccines are in development, and contributions to the rational design and optimal usage of these interventions are urgently needed. Infection involves the complex interaction of parasite dynamics, host immunity, and drug effects. The long life cycle (48 hours in the common human species) and synchronized replication cycle of the parasite population present significant challenges to modeling the dynamics of Plasmodium infection. Coupled with these, variation in immune recognition and drug action at different life cycle stages leads to further complexity. We review the development and progress of "within-host" models of Plasmodium infection, and how these have been applied to understanding and interpreting human infection and animal models of infection.
Collapse
Affiliation(s)
| | - Rosemary Aogo
- Kirby Institute, UNSW Sydney, Sydney, NSW, Australia
| | | | - James M McCaw
- School of Mathematics and Statistics, University of Melbourne, Melbourne, VIC, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia.,Peter Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital and University of Melbourne, Melbourne, VIC, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Ashraful Haque
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | | | | |
Collapse
|
21
|
Cooper MM, Loiseau C, McCarthy JS, Doolan DL. Human challenge models: tools to accelerate the development of malaria vaccines. Expert Rev Vaccines 2019; 18:241-251. [PMID: 30732492 DOI: 10.1080/14760584.2019.1580577] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Malaria challenge models, where healthy human volunteers are intentionally infected with Plasmodium species parasites under controlled conditions, can be undertaken in several well-defined ways. These challenge models enable evaluation of the kinetics of parasite growth and clearance, host-pathogen interactions and the host immune response. They can facilitate discovery of candidate diagnostic biomarkers and novel vaccine targets. As translational tools they can facilitate testing of candidate vaccines and drugs and evaluation of diagnostic tests. AREAS COVERED Until recently, malaria human challenge models have been limited to only a few Plasmodium falciparum strains and used exclusively in malaria-naïve volunteers in non-endemic regions. Several recent advances include the use of alternate P. falciparum strains and other species of Plasmodia, as well as strains attenuated by chemical, radiation or genetic modification, and the conduct of studies in pre-exposed individuals. Herein, we discuss how this diversification is enabling more thorough vaccine efficacy testing and informing rational vaccine development. EXPERT OPINION The ability to comprehensively evaluate vaccine efficacy in controlled settings will continue to accelerate the translation of candidate malaria vaccines to the clinic, and inform the development and optimisation of potential vaccines that would be effective against multiple strains in geographically and demographically diverse settings.
Collapse
Affiliation(s)
- Martha M Cooper
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - Claire Loiseau
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - James S McCarthy
- b Infectious Diseases Programme , QIMR Berghofer Medical Research Institute , Brisbane , Australia
| | - Denise L Doolan
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| |
Collapse
|
22
|
Beeson JG, Kurtovic L, Dobaño C, Opi DH, Chan JA, Feng G, Good MF, Reiling L, Boyle MJ. Challenges and strategies for developing efficacious and long-lasting malaria vaccines. Sci Transl Med 2019; 11:11/474/eaau1458. [DOI: 10.1126/scitranslmed.aau1458] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/05/2018] [Accepted: 11/02/2018] [Indexed: 12/24/2022]
Abstract
Although there has been major recent progress in malaria vaccine development, substantial challenges remain for achieving highly efficacious and durable vaccines against Plasmodium falciparum and Plasmodium vivax malaria. Greater knowledge of mechanisms and key targets of immunity are needed to accomplish this goal, together with new strategies for generating potent, long-lasting, functional immunity against multiple antigens. Implementation considerations in endemic areas will ultimately affect vaccine effectiveness, so innovations to simplify and enhance delivery are also needed. Whereas challenges remain, recent exciting progress and emerging knowledge promise hope for the future of malaria vaccines.
Collapse
|
23
|
McCall MBB, Kremsner PG, Mordmüller B. Correlating efficacy and immunogenicity in malaria vaccine trials. Semin Immunol 2018; 39:52-64. [PMID: 30219621 DOI: 10.1016/j.smim.2018.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022]
Abstract
The availability of an effective and appropriately implemented malaria vaccine would form a crucial cornerstone of public health efforts to fight this disease. Despite many decades of research, however, no malaria vaccine has yet shown satisfactory protective efficacy or been rolled-out. Validated immunological substitute endpoints have the potential to accelerate clinical vaccine development by reducing the required complexity, size, duration and cost of clinical trials. Besides facilitating clinical development of existing vaccine candidates, understanding immunological mechanisms of protection may drive the development of fundamentally new vaccination approaches. In this review we focus on correlates of protection in malaria vaccine development: Does immunogenicity predict malaria vaccine efficacy and why is this question particularly difficult? Have immunological correlates accelerated malaria vaccine development in the past and will they facilitate it in the future? Does Controlled Human Malaria Infection represent a valid model for identifying such immunological correlates, or a correlate of protection against naturally-acquired malaria in itself?
Collapse
Affiliation(s)
- Matthew B B McCall
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
| | - Peter G Kremsner
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| |
Collapse
|
24
|
Production, quality control, stability, and potency of cGMP-produced Plasmodium falciparum RH5.1 protein vaccine expressed in Drosophila S2 cells. NPJ Vaccines 2018; 3:32. [PMID: 30131879 PMCID: PMC6098134 DOI: 10.1038/s41541-018-0071-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/29/2018] [Accepted: 06/01/2018] [Indexed: 11/08/2022] Open
Abstract
Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is a leading asexual blood-stage vaccine candidate for malaria. In preparation for clinical trials, a full-length PfRH5 protein vaccine called “RH5.1” was produced as a soluble product under cGMP using the ExpreS2 platform (based on a Drosophila melanogaster S2 stable cell line system). Following development of a high-producing monoclonal S2 cell line, a master cell bank was produced prior to the cGMP campaign. Culture supernatants were processed using C-tag affinity chromatography followed by size exclusion chromatography and virus-reduction filtration. The overall process yielded >400 mg highly pure RH5.1 protein. QC testing showed the MCB and the RH5.1 product met all specified acceptance criteria including those for sterility, purity, and identity. The RH5.1 vaccine product was stored at −80 °C and is stable for over 18 months. Characterization of the protein following formulation in the adjuvant system AS01B showed that RH5.1 is stable in the timeframe needed for clinical vaccine administration, and that there was no discernible impact on the liposomal formulation of AS01B following addition of RH5.1. Subsequent immunization of mice confirmed the RH5.1/AS01B vaccine was immunogenic and could induce functional growth inhibitory antibodies against blood-stage P. falciparum in vitro. The RH5.1/AS01B was judged suitable for use in humans and has since progressed to phase I/IIa clinical trial. Our data support the future use of the Drosophila S2 cell and C-tag platform technologies to enable cGMP-compliant biomanufacture of other novel and “difficult-to-express” recombinant protein-based vaccines. A vaccine candidate for blood-stage malaria has overcome previous hurdles to enter clinical trials. The protein PfRH5 is an essential blood-stage infection facilitator of malarial parasite Plasmodium falciparum, and a promising target for vaccine strategies. Unfortunately, efforts to produce the protein in an immunogenic, clinically-viable way have been met with difficulty. Here, researchers led by Simon Draper, from the UK’s Jenner Institute, used a fruit fly expression system to produce over 400 mg of high-purity protein. Formulated with an immunity-boosting adjuvant, the vaccine elicited antibodies in mice that proved inhibitory to blood-stage P. falciparum during in vitro assays. The PfRH5 vaccine candidate and its adjuvant have been approved for a clinical trial in the UK, and the authors hope that the expression system used may be beneficial in the expression of other ‘difficult’ proteins.
Collapse
|
25
|
Collins KA, Wang CY, Adams M, Mitchell H, Rampton M, Elliott S, Reuling IJ, Bousema T, Sauerwein R, Chalon S, Möhrle JJ, McCarthy JS. A controlled human malaria infection model enabling evaluation of transmission-blocking interventions. J Clin Invest 2018; 128:1551-1562. [PMID: 29389671 PMCID: PMC5873858 DOI: 10.1172/jci98012] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/30/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND. Drugs and vaccines that can interrupt the transmission of Plasmodium falciparum will be important for malaria control and elimination. However, models for early clinical evaluation of candidate transmission-blocking interventions are currently unavailable. Here, we describe a new model for evaluating malaria transmission from humans to Anopheles mosquitoes using controlled human malaria infection (CHMI). METHODS. Seventeen healthy malaria-naive volunteers underwent CHMI by intravenous inoculation of P. falciparum–infected erythrocytes to initiate blood-stage infection. Seven to eight days after inoculation, participants received piperaquine (480 mg) to attenuate asexual parasite replication while allowing gametocytes to develop and mature. Primary end points were development of gametocytemia, the transmissibility of gametocytes from humans to mosquitoes, and the safety and tolerability of the CHMI transmission model. To investigate in vivo gametocytocidal drug activity in this model, participants were either given an experimental antimalarial, artefenomel (500 mg), or a known gametocytocidal drug, primaquine (15 mg), or remained untreated during the period of gametocyte carriage. RESULTS. Male and female gametocytes were detected in all participants, and transmission to mosquitoes was achieved from 8 of 11 (73%) participants evaluated. Compared with results in untreated controls (n = 7), primaquine (15 mg, n = 5) significantly reduced gametocyte burden (P = 0.01), while artefenomel (500 mg, n = 4) had no effect. Adverse events (AEs) were mostly mild or moderate. Three AEs were assessed as severe — fatigue, elevated alanine aminotransferase, and elevated aspartate aminotransferase — and were attributed to malaria infection. Transaminase elevations were transient, asymptomatic, and resolved without intervention. CONCLUSION. We report the safe and reproducible induction of P. falciparum gametocytes in healthy malaria-naive volunteers at densities infectious to mosquitoes, thereby demonstrating the potential for evaluating transmission-blocking interventions in this model. TRIAL REGISTRATION. ClinicalTrials.gov NCT02431637 and NCT02431650. FUNDING. Bill & Melinda Gates Foundation.
Collapse
Affiliation(s)
| | - Claire Yt Wang
- Queensland Paediatric Infectious Diseases (QPID) Laboratory, Centre for Children's Health Research, Brisbane, Queensland, Australia
| | - Matthew Adams
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Hayley Mitchell
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Melanie Rampton
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | - Isaie J Reuling
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | - Teun Bousema
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | - Robert Sauerwein
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| |
Collapse
|
26
|
Good MF, Miller LH. Interpreting challenge data from early phase malaria blood stage vaccine trials. Expert Rev Vaccines 2018; 17:189-196. [PMID: 29382292 DOI: 10.1080/14760584.2018.1435278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION As the quest for an effective blood stage malaria vaccine continues, there is increasing reliance on the use of controlled human malaria infections (CHMI) in non-endemic settings to test vaccine efficacy at the earliest possible time. This is seen as a way to accelerate vaccine research and quickly eliminate candidates with poor efficacy. Areas covered: The data from these studies need to be carefully examined and interpreted in light of the very different roles that antibody and cellular immunity play in protection and within the context of the distinct clinical sensitivities of volunteers living in malaria-non-endemic countries compared to those living in endemic countries. With current strategies, it is likely that vaccines with protective immunological 'signatures' will be missed and potentially good candidates discarded. Expert commentary: Efficacy data from early phase vaccine trials in non-endemic countries should not be used to decide whether or not to proceed to vaccine trials in endemic countries.
Collapse
Affiliation(s)
- Michael F Good
- a Institute for Glycomics , Griffith University , Queensland , Australia.,b Department of Medical Microbiology and Immunology, University of Alberta , Edmonton , Canada
| | - Louis H Miller
- c Malaria Cell Biology Section, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Bethesda , MD , USA
| |
Collapse
|
27
|
Masuta Y, Yamamoto T, Natsume-Kitatani Y, Kanuma T, Moriishi E, Kobiyama K, Mizuguchi K, Yasutomi Y, Ishii KJ. An Antigen-Free, Plasmacytoid Dendritic Cell-Targeting Immunotherapy To Bolster Memory CD8 + T Cells in Nonhuman Primates. THE JOURNAL OF IMMUNOLOGY 2018; 200:2067-2075. [PMID: 29431693 DOI: 10.4049/jimmunol.1701183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/07/2018] [Indexed: 01/10/2023]
Abstract
The priming, boosting, and restoration of memory cytotoxic CD8+ T lymphocytes by vaccination or immunotherapy in vivo is an area of active research. Particularly, nucleic acid-based compounds have attracted attention due to their ability to elicit strong Ag-specific CTL responses as a vaccine adjuvant. Nucleic acid-based compounds have been shown to act as anticancer monotherapeutic agents even without coadministration of cancer Ag(s); however, so far they have lacked efficacy in clinical trials. We recently developed a second-generation TLR9 agonist, a humanized CpG DNA (K3) complexed with schizophyllan (SPG), K3-SPG, a nonagonistic Dectin-1 ligand. K3-SPG was previously shown to act as a potent monoimmunotherapeutic agent against established tumors in mice in vivo. In this study we extend the monoimmunotherapeutic potential of K3-SPG to a nonhuman primate model. K3-SPG activated monkey plasmacytoid dendritic cells to produce both IFN-α and IL-12/23 p40 in vitro and in vivo. A single injection s.c. or i.v. with K3-SPG significantly increased the frequencies of activated memory CD8+ T cells in circulation, including Ag-specific memory CTLs, in cynomolgus macaques. This increase did not occur in macaques injected with free CpG K3 or polyinosinic-polycytidylic acid. Injection of 2 mg K3-SPG induced mild systemic inflammation, however, levels of proinflammatory serum cytokines and circulating neutrophil influx were lower than those induced by the same dose of polyinosinic-polycytidylic acid. Therefore, even in the absence of specific Ags, we show that K3-SPG has potent Ag-specific memory CTL response-boosting capabilities, highlighting its potential as a monoimmunotherapeutic agent for chronic infectious diseases and cancer.
Collapse
Affiliation(s)
- Yuji Masuta
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan.,Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.,Laboratories of Discovery Research, Nippon Shinyaku Co., Ltd., Kyoto 601-8550, Japan
| | - Takuya Yamamoto
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan.,Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Yayoi Natsume-Kitatani
- Laboratory of Bioinformatics, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan
| | - Tomohiro Kanuma
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan.,Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Eiko Moriishi
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan
| | - Kouji Kobiyama
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan.,Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.,Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Kenji Mizuguchi
- Laboratory of Bioinformatics, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan
| | - Yasuhiro Yasutomi
- Laboratory of Immunoregulation and Vaccine Research, Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki 305-0843, Japan
| | - Ken J Ishii
- Laboratory of Adjuvant Innovation, Center for Vaccine and Adjuvant Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan; .,Laboratory of Vaccine Science, World Premier International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| |
Collapse
|
28
|
Abstract
Controlled human malaria infection (CHMI) entails deliberate infection with malaria parasites either by mosquito bite or by direct injection of sporozoites or parasitized erythrocytes. When required, the resulting blood-stage infection is curtailed by the administration of antimalarial drugs. Inducing a malaria infection via inoculation with infected blood was first used as a treatment (malariotherapy) for neurosyphilis in Europe and the United States in the early 1900s. More recently, CHMI has been applied to the fields of malaria vaccine and drug development, where it is used to evaluate products in well-controlled early-phase proof-of-concept clinical studies, thus facilitating progression of only the most promising candidates for further evaluation in areas where malaria is endemic. Controlled infections have also been used to immunize against malaria infection. Historically, CHMI studies have been restricted by the need for access to insectaries housing infected mosquitoes or suitable malaria-infected individuals. Evaluation of vaccine and drug candidates has been constrained in these studies by the availability of a limited number of Plasmodium falciparum isolates. Recent advances have included cryopreservation of sporozoites, the manufacture of well-characterized and genetically distinct cultured malaria cell banks for blood-stage infection, and the availability of Plasmodium vivax-specific reagents. These advances will help to accelerate malaria vaccine and drug development by making the reagents for CHMI more widely accessible and also enabling a more rigorous evaluation with multiple parasite strains and species. Here we discuss the different applications of CHMI, recent advances in the use of CHMI, and ongoing challenges for consideration.
Collapse
|
29
|
Barton AJ, Hill J, Pollard AJ, Blohmke CJ. Transcriptomics in Human Challenge Models. Front Immunol 2017; 8:1839. [PMID: 29326715 PMCID: PMC5741696 DOI: 10.3389/fimmu.2017.01839] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/05/2017] [Indexed: 12/22/2022] Open
Abstract
Human challenge models, in which volunteers are experimentally infected with a pathogen of interest, provide the opportunity to directly identify both natural and vaccine-induced correlates of protection. In this review, we highlight how the application of transcriptomics to human challenge studies allows for the identification of novel correlates and gives insight into the immunological pathways required to develop functional immunity. In malaria challenge trials for example, innate immune pathways appear to play a previously underappreciated role in conferring protective immunity. Transcriptomic analyses of samples obtained in human challenge studies can also deepen our understanding of the immune responses preceding symptom onset, allowing characterization of innate immunity and early gene signatures, which may influence disease outcome. Influenza challenge studies demonstrate that these gene signatures have diagnostic potential in the context of pandemics, in which presymptomatic diagnosis of at-risk individuals could allow early initiation of antiviral treatment and help limit transmission. Furthermore, gene expression analysis facilitates the identification of host factors contributing to disease susceptibility, such as C4BPA expression in enterotoxigenic Escherichia coli infection. Overall, these studies highlight the exceptional value of transcriptional data generated in human challenge trials and illustrate the broad impact molecular data analysis may have on global health through rational vaccine design and biomarker discovery.
Collapse
Affiliation(s)
- Amber J Barton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Jennifer Hill
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Christoph J Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| |
Collapse
|
30
|
Kumar K, Srinivasan P, Nold MJ, Moch JK, Reiter K, Sturdevant D, Otto TD, Squires RB, Herrera R, Nagarajan V, Rayner JC, Porcella SF, Geromanos SJ, Haynes JD, Narum DL. Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach. Sci Rep 2017; 7:17146. [PMID: 29215067 PMCID: PMC5719419 DOI: 10.1038/s41598-017-17505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10-300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion.
Collapse
Affiliation(s)
- Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, USA.
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - J Kathleen Moch
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Dan Sturdevant
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - R Burke Squires
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Vijayaraj Nagarajan
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | | | - J David Haynes
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA.
| |
Collapse
|
31
|
Healer J, Cowman AF, Kaslow DC, Birkett AJ. Vaccines to Accelerate Malaria Elimination and Eventual Eradication. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025627. [PMID: 28490535 DOI: 10.1101/cshperspect.a025627] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.
Collapse
Affiliation(s)
- Julie Healer
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | - Alan F Cowman
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | | | | |
Collapse
|
32
|
Wockner LF, Hoffmann I, O'Rourke P, McCarthy JS, Marquart L. Comparison of statistical models to estimate parasite growth rate in the induced blood stage malaria model. Malar J 2017; 16:352. [PMID: 28841864 PMCID: PMC5574106 DOI: 10.1186/s12936-017-1999-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/20/2017] [Indexed: 11/28/2022] Open
Abstract
Background The efficacy of vaccines aimed at inhibiting the growth of malaria parasites in the blood can be assessed by comparing the growth rate of parasitaemia in the blood of subjects treated with a test vaccine compared to controls. In studies using induced blood stage malaria (IBSM), a type of controlled human malaria infection, parasite growth rate has been measured using models with the intercept on the y-axis fixed to the inoculum size. A set of statistical models was evaluated to determine an optimal methodology to estimate parasite growth rate in IBSM studies. Methods Parasite growth rates were estimated using data from 40 subjects published in three IBSM studies. Data was fitted using 12 statistical models: log-linear, sine-wave with the period either fixed to 48 h or not fixed; these models were fitted with the intercept either fixed to the inoculum size or not fixed. All models were fitted by individual, and overall by study using a mixed effects model with a random effect for the individual. Results Log-linear models and sine-wave models, with the period fixed or not fixed, resulted in similar parasite growth rate estimates (within 0.05 log10 parasites per mL/day). Average parasite growth rate estimates for models fitted by individual with the intercept fixed to the inoculum size were substantially lower by an average of 0.17 log10 parasites per mL/day (range 0.06–0.24) compared with non-fixed intercept models. Variability of parasite growth rate estimates across the three studies analysed was substantially higher (3.5 times) for fixed-intercept models compared with non-fixed intercept models. The same tendency was observed in models fitted overall by study. Modelling data by individual or overall by study had minimal effect on parasite growth estimates. Conclusions The analyses presented in this report confirm that fixing the intercept to the inoculum size influences parasite growth estimates. The most appropriate statistical model to estimate the growth rate of blood-stage parasites in IBSM studies appears to be a log-linear model fitted by individual and with the intercept estimated in the log-linear regression. Future studies should use this model to estimate parasite growth rates. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1999-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Leesa F Wockner
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - Isabell Hoffmann
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia.,Institute of Medical Biostatistics, Epidemiology and Informatics, Medical Center of Johannes Gutenberg University, 55101, Mainz, Germany
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia. .,School of Medicine, University of Queensland, Brisbane, QLD, 4072, Australia. .,Q-Pharm Pty Ltd, Brisbane, QLD, 4006, Australia.
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| |
Collapse
|
33
|
Srinivasan P, Baldeviano GC, Miura K, Diouf A, Ventocilla JA, Leiva KP, Lugo-Roman L, Lucas C, Orr-Gonzalez S, Zhu D, Villasante E, Soisson L, Narum DL, Pierce SK, Long CA, Diggs C, Duffy PE, Lescano AG, Miller LH. A malaria vaccine protects Aotus monkeys against virulent Plasmodium falciparum infection. NPJ Vaccines 2017; 2. [PMID: 28804644 PMCID: PMC5551459 DOI: 10.1038/s41541-017-0015-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Plasmodium falciparum protein, apical membrane antigen 1 forms a complex with another parasite protein, rhoptry neck protein 2, to initiate junction formation with the erythrocyte and is essential for merozoite invasion during the blood stage of infection. Consequently, apical membrane antigen 1 has been a target of vaccine development but vaccination with apical membrane antigen 1 alone in controlled human malaria infections failed to protect and showed limited efficacy in field trials. Here we show that vaccination with AMA1–RON2L complex in Freund’s adjuvant protects Aotus monkeys against a virulent Plasmodium falciparum infection. Vaccination with AMA1 alone gave only partial protection, delaying infection in one of eight animals. However, the AMA1–RON2L complex vaccine completely protected four of eight monkeys and substantially delayed infection (>25 days) in three of the other four animals. Interestingly, antibodies from monkeys vaccinated with the AMA1–RON2L complex had significantly higher neutralizing activity than antibodies from monkeys vaccinated with AMA1 alone. Importantly, we show that antibodies from animals vaccinated with the complex have significantly higher neutralization activity against non-vaccine type parasites. We suggest that vaccination with the AMA1–RON2L complex induces functional antibodies that better recognize AMA1 as it appears complexed with RON2 during merozoite invasion. These data justify progression of this next generation AMA1 vaccine towards human trials. A vaccine targeting a protein complex that allows malaria-causing parasite to enter red blood cells has been produced. Malaria caused by the parasite Plasmodium falciparum is an oft-deadly infectious disease without an effective vaccine. A team of researchers at the National Institutes of Health led by Prakash Srinivasan, currently at the Johns Hopkins Malaria Research Institute, United States, demonstrated the efficacy of a vaccine candidate that works by priming a host’s immune system to a parasitic protein complex required to form a junction with red blood cells, allowing entry and proliferation of the pathogen. The group’s vaccine conferred more effective protection in monkeys than prior candidates that targeted only one component of the parasitic protein complex. This research warrants a closer look into how this candidate, and others targeting the protein complex, can be used to prevent malaria in humans.
Collapse
Affiliation(s)
- Prakash Srinivasan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Karina P Leiva
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Luis Lugo-Roman
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Carmen Lucas
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Daming Zhu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Eileen Villasante
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD, USA
| | - Lorraine Soisson
- Malaria Vaccine Development Program, U.S. Agency for International Development, Washington, DC, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Carter Diggs
- Malaria Vaccine Development Program, U.S. Agency for International Development, Washington, DC, USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| |
Collapse
|
34
|
Payne RO, Griffin PM, McCarthy JS, Draper SJ. Plasmodium vivax Controlled Human Malaria Infection - Progress and Prospects. Trends Parasitol 2017; 33:141-150. [PMID: 27956060 PMCID: PMC5270241 DOI: 10.1016/j.pt.2016.11.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 11/01/2016] [Accepted: 11/04/2016] [Indexed: 02/06/2023]
Abstract
Modern controlled human malaria infection (CHMI) clinical trials have almost entirely focussed on Plasmodium falciparum, providing a highly informative means to investigate host-pathogen interactions as well as assess potential new prophylactic and therapeutic interventions. However, in recent years, there has been renewed interest in Plasmodium vivax, with CHMI models developed by groups in Colombia, the USA, and Australia. This review summarizes the published experiences, and examines the advantages and disadvantages of the different models that initiate infection either by mosquito bite or using a blood-stage inoculum. As for P. falciparum, CHMI studies with P. vivax will provide a platform for early proof-of-concept testing of drugs and vaccines, accelerating the development of novel interventions.
Collapse
Affiliation(s)
- Ruth O Payne
- The Jenner Institute Laboratories, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK; The Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, OX3 7LE, UK.
| | - Paul M Griffin
- QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, Queensland 4006, Australia; Q-Pharm Pty Ltd, Brisbane, Australia; Department of Medicine and Infectious Diseases, Mater Hospital and Mater Medical Research Institute, Brisbane, Australia; The University of Queensland, Brisbane, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, Queensland 4006, Australia; The University of Queensland, Brisbane, Australia
| | - Simon J Draper
- The Jenner Institute Laboratories, Old Road Campus Research Building, University of Oxford, Oxford, OX3 7DQ, UK.
| |
Collapse
|
35
|
Hodgson SH, Llewellyn D, Silk SE, Milne KH, Elias SC, Miura K, Kamuyu G, Juma EA, Magiri C, Muia A, Jin J, Spencer AJ, Longley RJ, Mercier T, Decosterd L, Long CA, Osier FH, Hoffman SL, Ogutu B, Hill AVS, Marsh K, Draper SJ. Changes in Serological Immunology Measures in UK and Kenyan Adults Post-controlled Human Malaria Infection. Front Microbiol 2016; 7:1604. [PMID: 27790201 PMCID: PMC5061779 DOI: 10.3389/fmicb.2016.01604] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/26/2016] [Indexed: 11/15/2022] Open
Abstract
Background: The timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049) (ClinicalTrials.gov NCT01465048) using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens [merozoite surface protein 1 (MSP1), apical membrane protein 1 (AMA1), and reticulocyte-binding protein homolog 5 (RH5)] and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA) assay and the antibody-dependent respiratory burst activity (ADRB) assay. Results:Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR) post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers. Quinine and atovaquone/proguanil, previously assumed to be removed by IgG purification, were identified as likely giving rise to aberrantly high in vitro GIA results. Conclusions: The ADRB activity assay is a promising functional assay that warrants further investigation as a measure of prior exposure to malaria and predictor of control of parasite growth. The CHMI model can be used to evaluate potential measures of naturally-acquired immunity to malaria.
Collapse
Affiliation(s)
| | | | - Sarah E Silk
- The Jenner Institute, University of Oxford Oxford, UK
| | | | - Sean C Elias
- The Jenner Institute, University of Oxford Oxford, UK
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIH-National Institute of Allergy and Infectious Diseases Rockville, MD, USA
| | - Gathoni Kamuyu
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome Trust Kilifi, Kenya
| | - Elizabeth A Juma
- Centre for Clinical Research, Kenya Medical Research InstituteNairobi, Kenya; Centre for Research in Therapeutic Sciences, Strathmore UniversityNairobi, Kenya
| | - Charles Magiri
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Alfred Muia
- Centre for Clinical Research, Kenya Medical Research Institute Nairobi, Kenya
| | - Jing Jin
- The Jenner Institute, University of Oxford Oxford, UK
| | | | | | - Thomas Mercier
- Division of Clinical Pharmacology, Hôpital Beaumont, Université de Lausanne Lausanne, Switzerland
| | - Laurent Decosterd
- Division of Clinical Pharmacology, Hôpital Beaumont, Université de Lausanne Lausanne, Switzerland
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIH-National Institute of Allergy and Infectious Diseases Rockville, MD, USA
| | - Faith H Osier
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome Trust Kilifi, Kenya
| | | | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research InstituteNairobi, Kenya; Centre for Research in Therapeutic Sciences, Strathmore UniversityNairobi, Kenya
| | | | - Kevin Marsh
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute-Wellcome TrustKilifi, Kenya; Department of Tropical Medicine, University of OxfordOxford, UK
| | | |
Collapse
|
36
|
Infectivity of Plasmodium falciparum in Malaria-Naive Individuals Is Related to Knob Expression and Cytoadherence of the Parasite. Infect Immun 2016; 84:2689-96. [PMID: 27382019 DOI: 10.1128/iai.00414-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/27/2016] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum is the most virulent human malaria parasite because of its ability to cytoadhere in the microvasculature. Nonhuman primate studies demonstrated relationships among knob expression, cytoadherence, and infectivity. This has not been examined in humans. Cultured clinical-grade P. falciparum parasites (NF54, 7G8, and 3D7B) and ex vivo-derived cell banks were characterized. Knob and knob-associated histidine-rich protein expression, CD36 adhesion, and antibody recognition of parasitized erythrocytes (PEs) were evaluated. Parasites from the cell banks were administered to malaria-naive human volunteers to explore infectivity. For the NF54 and 3D7B cell banks, blood was collected from the study participants for in vitro characterization. All parasites were infective in vivo However, infectivity of NF54 was dramatically reduced. In vitro characterization revealed that unlike other cell bank parasites, NF54 PEs lacked knobs and did not cytoadhere. Recognition of NF54 PEs by immune sera was observed, suggesting P. falciparum erythrocyte membrane protein 1 expression. Subsequent recovery of knob expression and CD36-mediated adhesion were observed in PEs derived from participants infected with NF54. Knobless cell bank parasites have a dramatic reduction in infectivity and the ability to adhere to CD36. Subsequent infection of malaria-naive volunteers restored knob expression and CD36-mediated cytoadherence, thereby showing that the human environment can modulate virulence.
Collapse
|
37
|
Muturi-Kioi V, Lewis D, Launay O, Leroux-Roels G, Anemona A, Loulergue P, Bodinham CL, Aerssens A, Groth N, Saul A, Podda A. Neutropenia as an Adverse Event following Vaccination: Results from Randomized Clinical Trials in Healthy Adults and Systematic Review. PLoS One 2016; 11:e0157385. [PMID: 27490698 PMCID: PMC4974007 DOI: 10.1371/journal.pone.0157385] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND In the context of early vaccine trials aimed at evaluating the safety profile of novel vaccines, abnormal haematological values, such as neutropenia, are often reported. It is therefore important to evaluate how these trials should be planned not to miss potentially important safety signals, but also to understand the implications and the clinical relevance. METHODOLOGY We report and discuss the results from five clinical trials (two with a new Shigella vaccine in the early stage of clinical development and three with licensed vaccines) where the absolute neutrophil counts (ANC) were evaluated before and after vaccination. Additionally, we have performed a systematic review of the literature on cases of neutropenia reported during vaccine trials to discuss our results in a more general context. PRINCIPAL FINDINGS Both in our clinical trials and in the literature review, several cases of neutropenia have been reported, in the first two weeks after vaccination. However, neutropenia was generally transient and had a benign clinical outcome, after vaccination with either multiple novel candidates or well-known licensed vaccines. Additionally, the vaccine recipients with neutropenia frequently had lower baseline ANC than non-neutropenic vaccinees. In many instances neutropenia occurred in subjects of African descent, known to have lower ANC compared to western populations. CONCLUSIONS It is important to include ANC and other haematological tests in early vaccine trials to identify potential safety signals. Post-vaccination neutropenia is not uncommon, generally transient and clinically benign, but many vaccine trials do not have a sampling schedule that allows its detection. Given ethnic variability in the level of circulating neutrophils, normal ranges taking into account ethnicity should be used for determination of trial inclusion/exclusion criteria and classification of neutropenia related adverse events. TRIAL REGISTRATION ClinicalTrials.gov NCT02017899, NCT02034500, NCT01771367, NCT01765413, NCT02523287.
Collapse
Affiliation(s)
| | - David Lewis
- Surrey Clinical Research Centre, University of Surrey, Guildford, United Kingdom
| | - Odile Launay
- Université Paris Descartes, Sorbonne Paris cité, and Inserm CIC 1417, F-CRIN I-Reivac, Assistance Publique Hôpitaux de Paris, CIC Cochin-Pasteur, Paris, France
| | | | | | - Pierre Loulergue
- Université Paris Descartes, Sorbonne Paris cité, and Inserm CIC 1417, F-CRIN I-Reivac, Assistance Publique Hôpitaux de Paris, CIC Cochin-Pasteur, Paris, France
| | - Caroline L. Bodinham
- Surrey Clinical Research Centre, University of Surrey, Guildford, United Kingdom
| | | | | | - Allan Saul
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Audino Podda
- Novartis Vaccines Institute for Global Health, Siena, Italy
| |
Collapse
|
38
|
Plasmodium falciparum infection and age influence parasite growth inhibition mediated by IgG in Beninese infants. Acta Trop 2016; 159:111-9. [PMID: 27001144 DOI: 10.1016/j.actatropica.2016.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/10/2016] [Accepted: 03/17/2016] [Indexed: 11/22/2022]
Abstract
Antibodies that impede the invasion of Plasmodium falciparum (P. falciparum) merozoites into erythrocytes play a critical role in anti-malarial immunity. The Growth Inhibition Assay (GIA) is an in vitro measure of the functional capacity of such antibodies to limit erythrocyte invasion and/or parasite growth. Up to now, it is unclear whether growth-inhibitory activity correlates with protection from clinical disease and there are inconsistent results from studies performed with GIA. Studies that have focused on the relationship between IgGs and their in vitro parasite Growth Inhibition Activity (GIAc) in infants aged less than two years old are rare. Here, we used clinical and parasitological data to precisely define symptomatic or asymptomatic infection with P. falciparum in groups of infants followed-up actively for 18 months post-natally. We quantified the levels of IgG1 and IgG3 directed to a panel of candidate P. falciparum vaccine antigens (AMA-1, MSP1, 2, 3 and GLURP) using ELISA and the functional activity of IgG was quantified using GIA. Data were then correlated with individuals' infection status. At 18 months of age, infants harbouring infections at the time of blood sampling had an average 19% less GIAc than those not infected (p=0.004, multivariate linear regression). GIAc decreased from 12 to 18 months of age (p=0.003, Wilcoxon matched pairs test). Antibody levels quantified at 18 months in infants were strongly correlated with their exposure to malarial infection, however GIAc was not correlated with malaria infectious status (asymptomatic and symptomatic groups). In conclusion, both infection status at blood draw and age influence parasite growth inhibition mediated by IgG in the GIA. Both factors must be taken into account when correlations between GIAc and anti-malarial protection or vaccine efficacy have to be made.
Collapse
|
39
|
Weeratna RD, Chikh G, Zhang L, Fraser JD, Thorn JM, Merson JR, McCluskie MJ, Champion BR, Davis HL. Immunogenicity of a peptide-based anti-IgE conjugate vaccine in non-human primates. Immun Inflamm Dis 2016; 4:135-147. [PMID: 27957325 PMCID: PMC4879460 DOI: 10.1002/iid3.98] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 01/06/2016] [Accepted: 01/12/2016] [Indexed: 01/02/2023] Open
Abstract
The anti-human immunoglobulin E (IgE) monoclonal antibody, omalizumab (Xolair®, Genentech, South San Fransisco, CA), is effective in the treatment of poorly controlled moderate to severe allergic asthma and chronic idiopathic urticaria. It acts by specifically binding to the constant domain (Cϵ3) of free human IgE in the blood and interstitial fluid. Although efficacious, use of omalizumab is limited due to restrictions on patient weight and pre-existing IgE levels, and frequent dosing (q2-4 weeks). A vaccine inducing anti-IgE antibodies has the potential for similar clinical benefits with less frequent dosing and relatively lower cost of goods. We developed a vaccine containing two IgE peptide-conjugates targeting the Cϵ3 domain of human IgE. As part of preclinical evaluation of the vaccine to optimize formulation and dose prior to initiating clinical studies, we evaluated the vaccine in non-human primates, and demonstrate the induction of anti-peptide antibodies that can bind to conformationally intact human IgE and are capable, at least in some animals, of substantial lowering circulating IgE levels.
Collapse
Affiliation(s)
| | - Ghania Chikh
- Pfizer Vaccine ImmunotherapeuticsOttawa LaboratoriesOttawaOntarioCanada
| | - Lu Zhang
- Pfizer Vaccine ImmunotherapeuticsOttawa LaboratoriesOttawaOntarioCanada
| | | | | | - James R. Merson
- Pfizer Biotherapeutics Pharmaceutical SciencesSt. LouisMissouriUSA
| | | | | | - Heather L. Davis
- Pfizer Vaccine ImmunotherapeuticsOttawa LaboratoriesOttawaOntarioCanada
| |
Collapse
|
40
|
Payne RO, Milne KH, Elias SC, Edwards NJ, Douglas AD, Brown RE, Silk SE, Biswas S, Miura K, Roberts R, Rampling TW, Venkatraman N, Hodgson SH, Labbé GM, Halstead FD, Poulton ID, Nugent FL, de Graaf H, Sukhtankar P, Williams NC, Ockenhouse CF, Kathcart AK, Qabar AN, Waters NC, Soisson LA, Birkett AJ, Cooke GS, Faust SN, Woods C, Ivinson K, McCarthy JS, Diggs CL, Vekemans J, Long CA, Hill AVS, Lawrie AM, Dutta S, Draper SJ. Demonstration of the Blood-Stage Plasmodium falciparum Controlled Human Malaria Infection Model to Assess Efficacy of the P. falciparum Apical Membrane Antigen 1 Vaccine, FMP2.1/AS01. J Infect Dis 2016; 213:1743-51. [PMID: 26908756 DOI: 10.1093/infdis/jiw039] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/21/2016] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Models of controlled human malaria infection (CHMI) initiated by mosquito bite have been widely used to assess efficacy of preerythrocytic vaccine candidates in small proof-of-concept phase 2a clinical trials. Efficacy testing of blood-stage malaria parasite vaccines, however, has generally relied on larger-scale phase 2b field trials in malaria-endemic populations. We report the use of a blood-stage P. falciparum CHMI model to assess blood-stage vaccine candidates, using their impact on the parasite multiplication rate (PMR) as the primary efficacy end point. METHODS Fifteen healthy United Kingdom adult volunteers were vaccinated with FMP2.1, a protein vaccine that is based on the 3D7 clone sequence of apical membrane antigen 1 (AMA1) and formulated in Adjuvant System 01 (AS01). Twelve vaccinees and 15 infectivity controls subsequently underwent blood-stage CHMI. Parasitemia was monitored by quantitative real-time polymerase chain reaction (PCR) analysis, and PMR was modeled from these data. RESULTS FMP2.1/AS01 elicited anti-AMA1 T-cell and serum antibody responses. Analysis of purified immunoglobulin G showed functional growth inhibitory activity against P. falciparum in vitro. There were no vaccine- or CHMI-related safety concerns. All volunteers developed blood-stage parasitemia, with no impact of the vaccine on PMR. CONCLUSIONS FMP2.1/AS01 demonstrated no efficacy after blood-stage CHMI. However, the model induced highly reproducible infection in all volunteers and will accelerate proof-of-concept testing of future blood-stage vaccine candidates. CLINICAL TRIALS REGISTRATION NCT02044198.
Collapse
Affiliation(s)
- Ruth O Payne
- Jenner Institute Laboratories Centre for Clinical Vaccinology and Tropical Medicine
| | | | | | | | | | | | | | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda
| | | | - Thomas W Rampling
- Jenner Institute Laboratories Centre for Clinical Vaccinology and Tropical Medicine
| | - Navin Venkatraman
- Jenner Institute Laboratories Centre for Clinical Vaccinology and Tropical Medicine
| | - Susanne H Hodgson
- Jenner Institute Laboratories Centre for Clinical Vaccinology and Tropical Medicine
| | | | | | - Ian D Poulton
- Centre for Clinical Vaccinology and Tropical Medicine
| | | | - Hans de Graaf
- National Institute for Health Research (NIHR) Wellcome Trust Clinical Research Facility, University Hospital Southampton National Health Service (NHS) Foundation Trust Faculty of Medicine, University of Southampton
| | - Priya Sukhtankar
- National Institute for Health Research (NIHR) Wellcome Trust Clinical Research Facility, University Hospital Southampton National Health Service (NHS) Foundation Trust Faculty of Medicine, University of Southampton
| | - Nicola C Williams
- Centre for Statistics in Medicine Botnar Research Centre, University of Oxford
| | - Christian F Ockenhouse
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland PATH Malaria Vaccine Initiative
| | - April K Kathcart
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Aziz N Qabar
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Norman C Waters
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | | | | | - Graham S Cooke
- NIHR Wellcome Trust Clinical Research Facility, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Saul N Faust
- National Institute for Health Research (NIHR) Wellcome Trust Clinical Research Facility, University Hospital Southampton National Health Service (NHS) Foundation Trust Faculty of Medicine, University of Southampton
| | | | | | | | | | | | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda
| | | | | | - Sheetij Dutta
- Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | | |
Collapse
|
41
|
Abstract
There have been significant decreases in malaria mortality and morbidity in the last 10-15 years, and the most advanced pre-erythrocytic malaria vaccine, RTS,S, received a positive opinion from European regulators in July 2015. However, no blood-stage vaccine has reached a phase III trial. The first part of this review summarizes the pros and cons of various assays and models that have been and will be used to predict the efficacy of blood-stage vaccines. In the second part, blood-stage vaccine candidates that showed some efficacy in human clinical trials or controlled human malaria infection models are discussed. Then, candidates under clinical investigation are described in the third part, and other novel candidates and strategies are reviewed in the last part.
Collapse
Affiliation(s)
- Kazutoyo Miura
- a Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
| |
Collapse
|
42
|
Beeson JG, Drew DR, Boyle MJ, Feng G, Fowkes FJI, Richards JS. Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria. FEMS Microbiol Rev 2016; 40:343-72. [PMID: 26833236 PMCID: PMC4852283 DOI: 10.1093/femsre/fuw001] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2016] [Indexed: 01/11/2023] Open
Abstract
Malaria accounts for an enormous burden of disease globally, with Plasmodium falciparum accounting for the majority of malaria, and P. vivax being a second important cause, especially in Asia, the Americas and the Pacific. During infection with Plasmodium spp., the merozoite form of the parasite invades red blood cells and replicates inside them. It is during the blood-stage of infection that malaria disease occurs and, therefore, understanding merozoite invasion, host immune responses to merozoite surface antigens, and targeting merozoite surface proteins and invasion ligands by novel vaccines and therapeutics have been important areas of research. Merozoite invasion involves multiple interactions and events, and substantial processing of merozoite surface proteins occurs before, during and after invasion. The merozoite surface is highly complex, presenting a multitude of antigens to the immune system. This complexity has proved challenging to our efforts to understand merozoite invasion and malaria immunity, and to developing merozoite antigens as malaria vaccines. In recent years, there has been major progress in this field, and several merozoite surface proteins show strong potential as malaria vaccines. Our current knowledge on this topic is reviewed, highlighting recent advances and research priorities. The authors summarize current knowledge of merozoite surface proteins of malaria parasites; their function in invasion, processing of surface proteins before, during and after invasion, their importance as targets of immunity, and the current status of malaria vaccines that target merozoite surface proteins.
Collapse
Affiliation(s)
- James G Beeson
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Gaoqian Feng
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Epidemiology and Preventive Medicine, Monash University, Clayton, Victoria, Australia School of Population Health, University of Melbourne, Parkville, Victoria, Australia
| | - Jack S Richards
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
43
|
Ewer KJ, Sierra-Davidson K, Salman AM, Illingworth JJ, Draper SJ, Biswas S, Hill AVS. Progress with viral vectored malaria vaccines: A multi-stage approach involving "unnatural immunity". Vaccine 2015; 33:7444-51. [PMID: 26476366 PMCID: PMC4687526 DOI: 10.1016/j.vaccine.2015.09.094] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/17/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022]
Abstract
Viral vectors used in heterologous prime-boost regimens are one of very few vaccination approaches that have yielded significant protection against controlled human malaria infections. Recently, protection induced by chimpanzee adenovirus priming and modified vaccinia Ankara boosting using the ME-TRAP insert has been correlated with the induction of potent CD8(+) T cell responses. This regimen has progressed to field studies where efficacy against infection has now been reported. The same vectors have been used pre-clinically to identify preferred protective antigens for use in vaccines against the pre-erythrocytic, blood-stage and mosquito stages of malaria and this work is reviewed here for the first time. Such antigen screening has led to the prioritization of the PfRH5 blood-stage antigen, which showed efficacy against heterologous strain challenge in non-human primates, and vectors encoding this antigen are in clinical trials. This, along with the high transmission-blocking activity of some sexual-stage antigens, illustrates well the capacity of such vectors to induce high titre protective antibodies in addition to potent T cell responses. All of the protective responses induced by these vectors exceed the levels of the same immune responses induced by natural exposure supporting the view that, for subunit vaccines to achieve even partial efficacy in humans, "unnatural immunity" comprising immune responses of very high magnitude will need to be induced.
Collapse
Affiliation(s)
- Katie J Ewer
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK.
| | - Kailan Sierra-Davidson
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK; Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852, USA
| | - Ahmed M Salman
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Simon J Draper
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Adrian V S Hill
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| |
Collapse
|
44
|
Birkett AJ. Building an effective malaria vaccine pipeline to address global needs. Vaccine 2015; 33:7538-43. [PMID: 26469721 DOI: 10.1016/j.vaccine.2015.09.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/25/2015] [Accepted: 09/29/2015] [Indexed: 02/08/2023]
Abstract
Despite impressive gains over the last 15 years in reducing the mortality associated with malaria, it remains a public health emergency. New interventions, such as vaccines, are needed to ensure that previous gains serve as a foundation for future progress. Vaccines have the potential to prevent severe disease and death in those most vulnerable, and to accelerate elimination and eradication by breaking the cycle of parasite transmission. The pipeline is as healthy as it has ever been, with approaches targeting different stages of the parasite lifecycle using an array of technologies. This article reviews recent progress and reviews key considerations in the quest to develop products that are aligned with the unmet medical need.
Collapse
Affiliation(s)
- Ashley J Birkett
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC 20001-2621, USA.
| |
Collapse
|
45
|
Draper SJ, Angov E, Horii T, Miller LH, Srinivasan P, Theisen M, Biswas S. Recent advances in recombinant protein-based malaria vaccines. Vaccine 2015; 33:7433-43. [PMID: 26458807 PMCID: PMC4687528 DOI: 10.1016/j.vaccine.2015.09.093] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 09/05/2015] [Accepted: 09/28/2015] [Indexed: 01/03/2023]
Abstract
Protein-based vaccines remain the cornerstone approach for B cell and antibody induction against leading target malaria antigens. Advances in antigen selection, immunogen design and epitope-focusing are advancing the field. New heterologous expression platforms are enabling cGMP production of next-generation protein vaccines. Next-generation antigens, protein-based immunogens and virus-like particle (VLP) delivery platforms are in clinical development. Protein-based vaccines will form part of a highly effective multi-component/multi-stage/multi-antigen subunit formulation against malaria.
Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle–including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed.
Collapse
Affiliation(s)
- Simon J Draper
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
| | - Evelina Angov
- Walter Reed Army Institute of Research, U. S. Military Malaria Research Program, Malaria Vaccine Branch, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 561-873, Japan
| | - Louis H Miller
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Prakash Srinivasan
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark; Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
| |
Collapse
|
46
|
McCluskie MJ, Thorn J, Gervais DP, Stead DR, Zhang N, Benoit M, Cartier J, Kim IJ, Bhattacharya K, Finneman JI, Merson JR, Davis HL. Anti-nicotine vaccines: Comparison of adjuvanted CRM197 and Qb-VLP conjugate formulations for immunogenicity and function in non-human primates. Int Immunopharmacol 2015; 29:663-671. [PMID: 26404190 DOI: 10.1016/j.intimp.2015.09.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 09/02/2015] [Accepted: 09/14/2015] [Indexed: 12/22/2022]
Abstract
Anti-nicotine vaccines comprise nicotine-like haptens conjugated to a carrier protein plus adjuvant(s). Unfortunately, those tested clinically have failed to improve overall long term quit rates. We had shown in mice that carrier, hapten, linker, hapten load (number of haptens per carrier molecule), aggregation and adducts, as well as adjuvants influence the function of antibodies (Ab) induced. Herein, we tested an optimized antigen, NIC7-CRM, comprised of 5-aminoethoxy-nicotine (NIC7) conjugated to genetically detoxified diphtheria toxin (CRM197), with hapten load of ~16, no aggregation (~100% monomer) and minimal adducts. NIC7-CRM was tested in non-human primates (NHP) and compared to NIC-VLP, which has the same hapten and carrier as the clinical-stage CYT002-NicQb but a slightly different linker and lower hapten load. With alum as sole adjuvant, NIC7-CRM was superior to NIC-VLP for Ab titer, avidity and ex vivo function (83% and 27% nicotine binding at 40ng/mL respectively), but equivalent for in vivo function after intravenous [IV] nicotine challenge (brain levels reduced ~10%). CpG adjuvant added to NIC7-CRM/alum further enhanced the Ab responses and both ex vivo function (100% bound) and in vivo function (~80% reduction in brain). Thus, both optimal antigen design and CpG adjuvant were required to achieve a highly functional vaccine. The compelling NHP data with NIC7-CRM with alum/CpG supported human testing, currently underway.
Collapse
Affiliation(s)
| | - Jennifer Thorn
- Pfizer Biotherapeutics Pharmaceutical Sciences, St. Louis, MO, USA
| | | | - David R Stead
- Pfizer Vaccine Immunotherapeutics, La Jolla, CA, USA
| | - Ningli Zhang
- Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON, Canada
| | - Michelle Benoit
- Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON, Canada
| | - Janna Cartier
- Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON, Canada
| | - In-Jeong Kim
- Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON, Canada
| | | | - Jari I Finneman
- Pfizer Biotherapeutics Pharmaceutical Sciences, St. Louis, MO, USA
| | | | - Heather L Davis
- Pfizer Vaccine Immunotherapeutics, Ottawa Laboratories, Ottawa, ON, Canada
| |
Collapse
|
47
|
Llewellyn D, Miura K, Fay MP, Williams AR, Murungi LM, Shi J, Hodgson SH, Douglas AD, Osier FH, Fairhurst RM, Diakite M, Pleass RJ, Long CA, Draper SJ. Standardization of the antibody-dependent respiratory burst assay with human neutrophils and Plasmodium falciparum malaria. Sci Rep 2015; 5:14081. [PMID: 26373337 PMCID: PMC4571651 DOI: 10.1038/srep14081] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 08/17/2015] [Indexed: 01/09/2023] Open
Abstract
The assessment of naturally-acquired and vaccine-induced immunity to blood-stage Plasmodium falciparum malaria is of long-standing interest. However, the field has suffered from a paucity of in vitro assays that reproducibly measure the anti-parasitic activity induced by antibodies in conjunction with immune cells. Here we optimize the antibody-dependent respiratory burst (ADRB) assay, which assesses the ability of antibodies to activate the release of reactive oxygen species from human neutrophils in response to P. falciparum blood-stage parasites. We focus particularly on assay parameters affecting serum preparation and concentration, and importantly assess reproducibility. Our standardized protocol involves testing each serum sample in singlicate with three independent neutrophil donors, and indexing responses against a standard positive control of pooled hyper-immune Kenyan sera. The protocol can be used to quickly screen large cohorts of samples from individuals enrolled in immuno-epidemiological studies or clinical vaccine trials, and requires only 6 μL of serum per sample. Using a cohort of 86 samples, we show that malaria-exposed individuals induce higher ADRB activity than malaria-naïve individuals. The development of the ADRB assay complements the use of cell-independent assays in blood-stage malaria, such as the assay of growth inhibitory activity, and provides an important standardized cell-based assay in the field.
Collapse
Affiliation(s)
- David Llewellyn
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, 20852, USA
| | - Michael P. Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Andrew R. Williams
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
| | - Linda M. Murungi
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
- KEMRI Centre for Geographic Medicine Research, Coast, P.O. Box 230-80108, Kilifi, Kenya
| | - Jianguo Shi
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Susanne H. Hodgson
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
| | - Alexander D. Douglas
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
| | - Faith H. Osier
- KEMRI Centre for Geographic Medicine Research, Coast, P.O. Box 230-80108, Kilifi, Kenya
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, 20852, USA
| | - Mahamadou Diakite
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy and Odonto-stomatology, University of Bamako, Bamako, Mali
| | - Richard J. Pleass
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, 20852, USA
| | - Simon J. Draper
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK
| |
Collapse
|
48
|
Stanisic DI, Liu XQ, De SL, Batzloff MR, Forbes T, Davis CB, Sekuloski S, Chavchich M, Chung W, Trenholme K, McCarthy JS, Li T, Sim BKL, Hoffman SL, Good MF. Development of cultured Plasmodium falciparum blood-stage malaria cell banks for early phase in vivo clinical trial assessment of anti-malaria drugs and vaccines. Malar J 2015; 14:143. [PMID: 25890156 PMCID: PMC4392471 DOI: 10.1186/s12936-015-0663-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/24/2015] [Indexed: 11/18/2022] Open
Abstract
Background The ability to undertake controlled human malaria infection (CHMI) studies for preliminary evaluation of malaria vaccine candidates and anti-malaria drug efficacy has been limited by the need for access to sporozoite infected mosquitoes, aseptic, purified, cryopreserved sporozoites or blood-stage malaria parasites derived ex vivo from malaria infected individuals. Three different strategies are described for the manufacture of clinical grade cultured malaria cell banks suitable for use in CHMI studies. Methods Good Manufacturing Practices (GMP)-grade Plasmodium falciparum NF54, clinically isolated 3D7, and research-grade P. falciparum 7G8 blood-stage malaria parasites were cultured separately in GMP-compliant facilities using screened blood components and then cryopreserved to produce three P. falciparum blood-stage malaria cell banks. These cell banks were evaluated according to specific criteria (parasitaemia, identity, viability, sterility, presence of endotoxin, presence of mycoplasma or other viral agents and in vitro anti-malarial drug sensitivity of the cell bank malaria parasites) to ensure they met the criteria to permit product release according to GMP requirements. Results The P. falciparum NF54, 3D7 and 7G8 cell banks consisted of >78% ring stage parasites with a ring stage parasitaemia of >1.4%. Parasites were viable in vitro following thawing. The cell banks were free from contamination with bacteria, mycoplasma and a broad panel of viruses. The P. falciparum NF54, 3D7 and 7G8 parasites exhibited differential anti-malarial drug susceptibilities. The P. falciparum NF54 and 3D7 parasites were susceptible to all anti-malaria compounds tested, whereas the P. falciparum 7G8 parasites were resistant/had decreased susceptibility to four compounds. Following testing, all defined release criteria were met and the P. falciparum cell banks were deemed suitable for release. Ethical approval has been obtained for administration to human volunteers. Conclusions The production of cultured P. falciparum blood-stage malaria cell banks represents a suitable approach for the generation of material suitable for CHMI studies. A key feature of this culture-based approach is the ability to take research-grade material through to a product suitable for administration in clinical trials. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0663-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Xue Q Liu
- Institute for Glycomics, Griffith University, Southport, QLD, Australia.
| | - Sai Lata De
- Institute for Glycomics, Griffith University, Southport, QLD, Australia.
| | - Michael R Batzloff
- Institute for Glycomics, Griffith University, Southport, QLD, Australia.
| | - Tanya Forbes
- Institute for Glycomics, Griffith University, Southport, QLD, Australia.
| | | | - Silvana Sekuloski
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, University of Queensland, Herston, Australia.
| | | | - Wendy Chung
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, University of Queensland, Herston, Australia.
| | - Katharine Trenholme
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, University of Queensland, Herston, Australia.
| | - James S McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, University of Queensland, Herston, Australia.
| | - Tao Li
- Sanaria Inc, Rockville, MD, USA.
| | | | | | - Michael F Good
- Institute for Glycomics, Griffith University, Southport, QLD, Australia.
| |
Collapse
|
49
|
Molecular attributes of conjugate antigen influence function of antibodies induced by anti-nicotine vaccine in mice and non-human primates. Int Immunopharmacol 2015; 25:518-27. [PMID: 25737198 DOI: 10.1016/j.intimp.2015.02.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/29/2015] [Accepted: 02/17/2015] [Indexed: 11/20/2022]
Abstract
Anti-nicotine vaccines aim to prevent nicotine entering the brain, and thus reduce or eliminate the reward that drives nicotine addiction. Those tested in humans to date have failed to improve quit rates over placebo, possibly because antibody (Ab) responses were insufficient to sequester enough nicotine in the blood in the majority of subjects. We have previously shown in mice that the carrier, hapten and linker used in the nicotine conjugate antigen each influence the function (nicotine-binding capacity) of the Ab induced. Herein we have evaluated immunogenicity in mice of 27 lots of NIC7-CRM, a conjugate of 5-aminoethoxy-nicotine (Hapten 7) and a mutant nontoxic form of diphtheria toxin (CRM197), that differed in three antigen attributes, namely hapten load (number of haptens conjugated to each molecule of CRM197), degree of conjugate aggregation and presence of adducts (small molecules attached to CRM197 via a covalent bond during the conjugation process). A range of functional responses (reduced nicotine in the brain of immunized animals relative to non-immunized controls) were obtained with the different conjugates, which were adjuvanted with aluminum hydroxide and CpG TLR9 agonist. Trends for better functional responses in mice were obtained with conjugates having a hapten load of 11 to 18, a low level of high molecular mass species (HMMS) (i.e., not aggregated) and a low level of adducts and a more limited testing in cynomolgus monkeys confirmed these results. Thus hapten load, conjugate aggregation and presence of adducts are key antigen attributes that can influence Ab function induced by NIC7-CRM.
Collapse
|
50
|
Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure. PLoS One 2014; 9:e107903. [PMID: 25254500 PMCID: PMC4177865 DOI: 10.1371/journal.pone.0107903] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 08/17/2014] [Indexed: 11/19/2022] Open
Abstract
The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI) with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i) ChAd63-MVA immunization, ii) immunization and CHMI, and iii) primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i) total IgG responses before and after CHMI, ii) responses to allelic variants of MSP1 and AMA1, iii) functional growth inhibitory activity (GIA), iv) IgG avidity, and v) isotype responses (IgG1-4, IgA and IgM). These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other diseases targets, these data should help to guide further immuno-monitoring studies of vaccine-induced human antibody responses.
Collapse
|