1
|
Rapaka RR. How do adjuvants enhance immune responses? eLife 2024; 13:e101259. [PMID: 39136115 PMCID: PMC11321759 DOI: 10.7554/elife.101259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024] Open
Abstract
By altering which peptide antigens are presented to CD4+ T cells, adjuvants affect the specificity of the immune response.
Collapse
Affiliation(s)
- Rekha R Rapaka
- Center for Vaccine Development and Global Health, University of Maryland School of MedicineBaltimoreUnited States
- Moderna TherapeuticsCambridgeUnited States
| |
Collapse
|
2
|
Cui Y, Ho M, Hu Y, Shi Y. Vaccine adjuvants: current status, research and development, licensing, and future opportunities. J Mater Chem B 2024; 12:4118-4137. [PMID: 38591323 PMCID: PMC11180427 DOI: 10.1039/d3tb02861e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.
Collapse
Affiliation(s)
- Ying Cui
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
| | - Megan Ho
- Department of Bioengineering, University of California, Los Angeles, CA 90095, USA
| | - Yongjie Hu
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095, USA.
| | - Yuan Shi
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| |
Collapse
|
3
|
Apostólico JDS, Lunardelli VAS, Yamamoto MM, Cunha-Neto E, Boscardin SB, Rosa DS. Poly(I:C) Potentiates T Cell Immunity to a Dendritic Cell Targeted HIV-Multiepitope Vaccine. Front Immunol 2019; 10:843. [PMID: 31105693 PMCID: PMC6492566 DOI: 10.3389/fimmu.2019.00843] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 04/01/2019] [Indexed: 02/05/2023] Open
Abstract
Cellular immune responses are implicated in resistance to HIV and have been considered for the development of an effective vaccine. Despite their safety profile, subunit vaccines need to be delivered combined with an adjuvant. In the last years, in vivo antigen targeting to dendritic cells (DCs) using chimeric monoclonal antibodies (mAb) against the DC endocytic receptor DEC205/CD205 was shown to support long-term T cell immunity. Here, we evaluated the ability of different adjuvants to modulate specific cellular immune response when eight CD4+ HIV-derived epitopes (HIVBr8) were targeted to DEC205+ DCs in vivo. Immunization with two doses of αDECHIVBr8 mAb along with poly(I:C) induced Th1 cytokine production and higher frequency of HIV-specific polyfunctional and long-lived T cells than MPL or CpG ODN-assisted immunization. Although each adjuvant elicited responses against the 8 epitopes present in the vaccine, the magnitude of the T cell response was higher in the presence of poly(I:C). Moreover, poly(I:C) up regulated the expression of costimulatory molecules in both cDC1 and cDC2 DCs subsets. In summary, the use of poly(I:C) in a vaccine formulation that targets multiple epitopes to the DEC205 receptor improved the potency and the quality of HIV-specific responses when compared to other vaccine-adjuvant formulations. This study highlights the importance of the rational selection of antigen/adjuvant combination to potentiate the desired immune responses.
Collapse
Affiliation(s)
- Juliana de Souza Apostólico
- Laboratory of Experimental Vaccines, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil.,Institute for Investigation in Immunology (iii)-INCT, São Paulo, Brazil
| | - Victória Alves Santos Lunardelli
- Laboratory of Experimental Vaccines, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil.,Institute for Investigation in Immunology (iii)-INCT, São Paulo, Brazil
| | - Marcio Massao Yamamoto
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Edecio Cunha-Neto
- Institute for Investigation in Immunology (iii)-INCT, São Paulo, Brazil.,Laboratory of Clinical Immunology and Allergy (LIM60), School of Medicine-University of São Paulo, São Paulo, Brazil
| | - Silvia Beatriz Boscardin
- Institute for Investigation in Immunology (iii)-INCT, São Paulo, Brazil.,Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Daniela Santoro Rosa
- Laboratory of Experimental Vaccines, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil.,Institute for Investigation in Immunology (iii)-INCT, São Paulo, Brazil
| |
Collapse
|
4
|
Abstract
Safe and efficacious vaccines are arguably the most successful medical interventions of all time. Yet the ongoing discovery of new pathogens, along with emergence of antibiotic-resistant pathogens and a burgeoning population at risk of such infections, imposes unprecedented public health challenges. To meet these challenges, innovative strategies to discover and develop new or improved anti-infective vaccines are necessary. These approaches must intersect the most meaningful insights into protective immunity and advanced technologies with capabilities to deliver immunogens for optimal immune protection. This goal is considered through several recent advances in host-pathogen relationships, conceptual strides in vaccinology, and emerging technologies. Given a clear and growing risk of pandemic disease should the threat of infection go unmet, developing vaccines that optimize protective immunity against high-priority and antibiotic-resistant pathogens represents an urgent and unifying imperative.
Collapse
Affiliation(s)
- Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90024.,Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, California 90509; .,Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, California 90509.,Los Angeles Biomedical Research Institute, Torrance, California 90502
| | | |
Collapse
|
5
|
Luo L, Qin T, Huang Y, Zheng S, Bo R, Liu Z, Xing J, Hu Y, Liu J, Wang D. Exploring the immunopotentiation of Chinese yam polysaccharide poly(lactic-co-glycolic acid) nanoparticles in an ovalbumin vaccine formulation in vivo. Drug Deliv 2017; 24:1099-1111. [PMID: 28776443 PMCID: PMC8241064 DOI: 10.1080/10717544.2017.1359861] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/21/2017] [Accepted: 07/22/2017] [Indexed: 01/12/2023] Open
Abstract
Biocompatible and biodegradable poly(lactic-co-glycolic acid) (PLGA) has been approved by the US Food and Drug Administration and has frequently been used to develop potential vaccine delivery systems. The immunoregulation and immunopotentiation of Chinese yam polysaccharide (CYP) have been widely demonstrated. In the current study, cell uptake mechanisms in dendritic cells (DCs) were monitored in vitro using confocal laser scanning microscopy, transmission electron microscopy, and flow cytometry. To study a CYP-PLGA nanoparticle-adjuvanted delivery system, CYP and ovalbumin (OVA) were encapsulated in PLGA nanoparticles (CYPPs) to act as a vaccine, and the formulation was tested in immunized mice. The CYPPs more easily underwent uptake by DCs in vitro, and CYPP/OVA could stimulate more effective antigen-specific immune responses than any of the single-component formulations in vivo. Mice immunized using CYPP/OVA exhibited more secretion of OVA-specific IgG antibodies, better proliferation, and higher cytokine secretion by splenocytes and significant activation of CD3+CD4+ and CD3+CD8+ T cells. Overall, the CYPP/OVA formulation produced a stronger humoral and cellular immune response and a mixed Th1/Th2 immune response with a greater Th1 bias in comparison with the other formulations. In conclusion, the data demonstrate that the CYPP-adjuvanted delivery system has the potential to strengthen immune responses and lay the foundation for novel adjuvant design.
Collapse
Affiliation(s)
- Li Luo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Tao Qin
- Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal, Fujian Agriculture and Forestry University, Fuzhou, PR China
| | - Yifan Huang
- Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal, Fujian Agriculture and Forestry University, Fuzhou, PR China
| | - Sisi Zheng
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Ruonan Bo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Zhenguang Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Jie Xing
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Yuanliang Hu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Jiaguo Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Deyun Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
- Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal, Fujian Agriculture and Forestry University, Fuzhou, PR China
| |
Collapse
|
6
|
Li B, Yuan H, Chen L, Sun H, Hu J, Wei S, Zhao Z, Zou Q, Wu C. The influence of adjuvant on UreB protection against Helicobacter pylori through the diversity of CD4+ T-cell epitope repertoire. Oncotarget 2017; 8:68138-68152. [PMID: 28978104 PMCID: PMC5620244 DOI: 10.18632/oncotarget.19248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/20/2017] [Indexed: 02/06/2023] Open
Abstract
Adjuvants are widely used to enhance the effects of vaccines against pathogen infections. Interestingly, different adjuvants and vaccination routes usually induce dissimilar immune responses, and can even have completely opposite effects. The mechanism remains unclear. In this study, urease B subunit (UreB), an antigen of Helicobacter pylori (H. pylori) that can induce protective immune responses, was used as a model to vaccinate mice. We investigated the effects of different adjuvants and routes on consequent T cell epitope-specific targeting and protection against H. pylori infection. Comparison of the protective effects of UreB, administered either subcutaneously (sc) or intranasally (in), with the adjuvants AddaVax (sc), Complete Freund’s adjuvant (CFA; sc), or CpG oligonucleotide (CpG; sc or in), indicated that only CFA (sc) and CpG (in) were protective. Protective vaccines induced T cells targeting epitopes that differed from that targeted by control vaccination. Subsequent peptide vaccination demonstrated that only two of the identified epitopes were protective: UreB373–385 and UreB317–329. Overall, we found that both adjuvant and vaccination route affected the T cell response repertoire to antigen epitopes. The data obtained in this study contribute to improved characterization of the relationship between adjuvants, routes of vaccination, and epitope-specific T cell response repertoires.
Collapse
Affiliation(s)
- Bin Li
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Hanmei Yuan
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Li Chen
- Department of Blood Transfusion, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Heqiang Sun
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Jian Hu
- Department of Intensive Care Unit, Chengdu Military General Hospital, Chengdu, PR China.,Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Shanshan Wei
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Chao Wu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| |
Collapse
|
7
|
Martins KAO, Cooper CL, Stronsky SM, Norris SLW, Kwilas SA, Steffens JT, Benko JG, van Tongeren SA, Bavari S. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity. EBioMedicine 2015; 3:67-78. [PMID: 26870818 PMCID: PMC4739439 DOI: 10.1016/j.ebiom.2015.11.041] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 01/08/2023] Open
Abstract
Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development. Adjuvants can prolong the protection afforded by protein-based vaccines and impact adaptive immune responses Enhanced CD4 T cell responses, helper and effector, correlate with duration of protection Durable protection from ma-EBOV is associated with Tfh frequency, Th1 antibody titers, and effector CD4 T cells
Protein-based vaccines are extremely safe, but they sometimes require the addition of adjuvants to enhance immunogenicity. In this study, we compared the impact of multiple adjuvants on immunogenicity, focusing on the duration of vaccine-mediated protection in mice. We then looked at how each adjuvant impacted the immune response in order to identify correlates of that long lasting immunity. The most effective adjuvant/vaccine combinations elicited multifunctional CD4 T cell responses and a Th1-skewed antibody response. By transferring antigen-experienced CD4 T cells and serum into naïve animals, we demonstrated that both CD4 T cells and serum were critical for durable vaccine-mediated protection.
Collapse
Key Words
- Adjuvant
- BME, beta mercaptoethanol
- CD, cluster of differentiation
- DSCF, Dwass, Steel, Critchlow-Fligner
- Durable protection
- ELISA, Enzyme linked immunosorbent assay
- ELISPOT, enzyme-linked immunospot assay
- Ebola virus
- FACS, fluorescence activated cell sorting
- FBS, fetal bovine serum
- GP, glycoprotein
- IACUC, Institutional Animal Care and Use Committee
- IM, intramuscular
- IP, intraperitoneal
- IQR, interquartile range
- Immune correlates
- LN, lymph node
- MPLA, monophosphoryl lipid A
- NAb, neutralizing antibody
- Ns, not significant
- PBS, phosphate buffered saline
- PRR, pattern recognition receptor
- Pfu, plaque forming unit
- PsVNA, pseudovirion neutralization assay
- TLR, Toll-like receptor
- USAMRIID, United States Army Medical Research Institute of Infectious Diseases
- VLP, virus-like particle
- Vaccine
- ma-EBOV, mouse-adapted Ebola virus
Collapse
Affiliation(s)
- Karen A O Martins
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Christopher L Cooper
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Sabrina M Stronsky
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Sarah L W Norris
- Research Support Division, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Steven A Kwilas
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Jesse T Steffens
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Jacqueline G Benko
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Sean A van Tongeren
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA
| | - Sina Bavari
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, MD, USA.
| |
Collapse
|
8
|
Storcksdieck genannt Bonsmann M, Niezold T, Temchura V, Pissani F, Ehrhardt K, Brown EP, Osei-Owusu NY, Hannaman D, Hengel H, Ackerman ME, Streeck H, Nabi G, Tenbusch M, Überla K. Enhancing the Quality of Antibodies to HIV-1 Envelope by GagPol-Specific Th Cells. THE JOURNAL OF IMMUNOLOGY 2015; 195:4861-72. [PMID: 26466954 DOI: 10.4049/jimmunol.1501377] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/18/2015] [Indexed: 11/19/2022]
Abstract
The importance of Fc-dependent effector functions of Abs induced by vaccination is increasingly recognized. However, vaccination of mice against HIV envelope (Env) induced a skewed Th cell response leading to Env-specific Abs with reduced effector function. To overcome this bias, GagPol-specific Th cells were harnessed to provide intrastructural help for Env-specific B cells after immunization with virus-like particles containing GagPol and Env. This led to a balanced Env-specific humoral immune response with a more inflammatory Fc glycan profile. The increased quality in the Ab response against Env was confirmed by FcγR activation assays. Because the Env-specific Th cell response was also biased in human vaccinees, intrastructural help is an attractive novel approach to increase the efficacy of prophylactic HIV Env-based vaccines and may also be applicable to other particulate vaccines.
Collapse
Affiliation(s)
| | - Thomas Niezold
- Department of Molecular and Medical Virology, Ruhr-University Bochum, Bochum 44801, Germany
| | - Vladimir Temchura
- Department of Molecular and Medical Virology, Ruhr-University Bochum, Bochum 44801, Germany; Universitätsklinikum Erlangen, Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Franco Pissani
- U.S. Military HIV Research Program, Silver Spring, MD 20910
| | - Katrin Ehrhardt
- Department of Medical Microbiology and Hygiene, Institute of Virology, University Medical Center Freiburg, Freiburg 79106, Germany
| | - Eric P Brown
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755; and
| | | | | | - Hartmut Hengel
- Department of Medical Microbiology and Hygiene, Institute of Virology, University Medical Center Freiburg, Freiburg 79106, Germany
| | | | | | - Ghulam Nabi
- Department of Molecular and Medical Virology, Ruhr-University Bochum, Bochum 44801, Germany
| | - Matthias Tenbusch
- Department of Molecular and Medical Virology, Ruhr-University Bochum, Bochum 44801, Germany
| | - Klaus Überla
- Department of Molecular and Medical Virology, Ruhr-University Bochum, Bochum 44801, Germany; Universitätsklinikum Erlangen, Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany;
| |
Collapse
|
9
|
Merkenschlager J, Kassiotis G. Narrowing the Gap: Preserving Repertoire Diversity Despite Clonal Selection during the CD4 T Cell Response. Front Immunol 2015; 6:413. [PMID: 26322045 PMCID: PMC4531291 DOI: 10.3389/fimmu.2015.00413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/28/2015] [Indexed: 01/14/2023] Open
Abstract
T cell immunity relies on the generation and maintenance of a diverse repertoire of T cell antigen receptors (TCRs). The strength of signaling emanating from the TCR dictates the fate of T cells during development, as well as during the immune response. Whereas development of new T cells in the thymus increases the available TCR repertoire, clonal selection during the immune response narrows TCR diversity through the outgrowth of clonotypes with the fittest TCR. To ensure maintenance of TCR diversity in the antigen-selected repertoire, specific mechanisms can be envisaged that facilitate the participation of T cell clonotypes with less than best fit TCRs. Here, we summarize the evidence for the existence of such mechanisms that can prevent the loss of diversity. A number of T cell-autonomous or extrinsic factors can reverse clonotypic hierarchies set by TCR affinity for given antigen. Although not yet complete, understanding of these factors and their mechanism of action will be critical in interventional attempts to mold the antigen-selected TCR repertoire.
Collapse
Affiliation(s)
| | - George Kassiotis
- Mill Hill Laboratory, The Francis Crick Institute , London , UK ; Department of Medicine, Faculty of Medicine, Imperial College London , London , UK
| |
Collapse
|
10
|
Landry N, Pillet S, Favre D, Poulin JF, Trépanier S, Yassine-Diab B, Ward BJ. Influenza virus-like particle vaccines made in Nicotiana benthamiana elicit durable, poly-functional and cross-reactive T cell responses to influenza HA antigens. Clin Immunol 2014; 154:164-77. [PMID: 25128897 DOI: 10.1016/j.clim.2014.08.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/26/2014] [Accepted: 08/06/2014] [Indexed: 12/14/2022]
Abstract
Cell-mediated immunity plays a major role in long-lived, cross-reactive protection against influenza virus. We measured long-term poly-functional and cross-reactive T cell responses to influenza hemagglutinin (HA) elicited by a new plant-made Virus-Like Particle (VLP) vaccine targeting either H1N1 A/California/7/09 (H1) or H5N1 A/Indonesia/5/05 (H5). In two independent clinical trials, we characterized the CD4(+) and CD8(+) T cell homotypic and heterotypic responses 6 months after different vaccination regimens. Responses of VLP-vaccinated subjects were compared with placebo and/or a commercial trivalent inactivated vaccine (TIV:Fluzone™) recipients. Both H1 and H5 VLP vaccines elicited significantly greater poly-functional CD4(+) T cell responses than placebo and TIV. Poly-functional CD8(+) T cell responses were also observed after H1 VLP vaccination. Our results show that plant-made HA VLP vaccines elicit both strong antibody responses and poly-functional, cross-reactive memory T cells that persist for at least 6 months after vaccination.
Collapse
Affiliation(s)
- Nathalie Landry
- Medicago inc., 1020 Route de l'Église, Bureau 600, Québec, Qc G1V 3V9, Canada.
| | - Stéphane Pillet
- Medicago inc., 1020 Route de l'Église, Bureau 600, Québec, Qc G1V 3V9, Canada; Research Institute of the McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Qc H3G 1A4, Canada.
| | - David Favre
- ImmuneCarta, 201 President-Kennedy, Suite PK-3900, Montreal, Qc H2X 3Y7, Canada.
| | - Jean-François Poulin
- ImmuneCarta, 201 President-Kennedy, Suite PK-3900, Montreal, Qc H2X 3Y7, Canada.
| | - Sonia Trépanier
- Medicago inc., 1020 Route de l'Église, Bureau 600, Québec, Qc G1V 3V9, Canada.
| | - Bader Yassine-Diab
- ImmuneCarta, 201 President-Kennedy, Suite PK-3900, Montreal, Qc H2X 3Y7, Canada.
| | - Brian J Ward
- Research Institute of the McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Qc H3G 1A4, Canada.
| |
Collapse
|
11
|
Specificities of human CD4+ T cell responses to an inactivated flavivirus vaccine and infection: correlation with structure and epitope prediction. J Virol 2014; 88:7828-42. [PMID: 24789782 DOI: 10.1128/jvi.00196-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Tick-borne encephalitis (TBE) virus is endemic in large parts of Europe and Central and Eastern Asia and causes more than 10,000 annual cases of neurological disease in humans. It is closely related to the mosquito-borne yellow fever, dengue, Japanese encephalitis, and West Nile viruses, and vaccination with an inactivated whole-virus vaccine can effectively prevent clinical disease. Neutralizing antibodies are directed to the viral envelope protein (E) and an accepted correlate of immunity. However, data on the specificities of CD4(+) T cells that recognize epitopes in the viral structural proteins and thus can provide direct help to the B cells producing E-specific antibodies are lacking. We therefore conducted a study on the CD4(+) T cell response against the virion proteins in vaccinated people in comparison to TBE patients. The data obtained with overlapping peptides in interleukin-2 (IL-2) enzyme-linked immunosorbent spot (ELISpot) assays were analyzed in relation to the three-dimensional structures of the capsid (C) and E proteins as well as to epitope predictions based on major histocompatibility complex (MHC) class II peptide affinities. In the C protein, peptides corresponding to two out of four alpha helices dominated the response in both vaccinees and patients, whereas in the E protein concordance of immunodominance was restricted to peptides of a single domain (domain III). Epitope predictions were much better for C than for E and were especially erroneous for the transmembrane regions. Our data provide evidence for a strong impact of protein structural features that influence peptide processing, contributing to the discrepancies observed between experimentally determined and computer-predicted CD4(+) T cell epitopes. Importance: Tick-borne encephalitis virus is endemic in large parts of Europe and Asia and causes more than 10,000 annual cases of neurological disease in humans. It is closely related to yellow fever, dengue, Japanese encephalitis, and West Nile viruses, and vaccination with an inactivated vaccine can effectively prevent disease. Both vaccination and natural infection induce the formation of antibodies to a viral surface protein that neutralize the infectivity of the virus and mediate protection. B lymphocytes synthesizing these antibodies require help from other lymphocytes (helper T cells) which recognize small peptides derived from proteins contained in the viral particle. Which of these peptides dominate immune responses to vaccination and infection, however, was unknown. In our study we demonstrate which parts of the proteins contribute most strongly to the helper T cell response, highlight specific weaknesses of currently available approaches for their prediction, and demonstrate similarities and differences between vaccination and infection.
Collapse
|
12
|
Zhang W, Wang L, Liu Y, Chen X, Liu Q, Jia J, Yang T, Qiu S, Ma G. Immune responses to vaccines involving a combined antigen-nanoparticle mixture and nanoparticle-encapsulated antigen formulation. Biomaterials 2014; 35:6086-97. [PMID: 24780166 DOI: 10.1016/j.biomaterials.2014.04.022] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 04/06/2014] [Indexed: 01/09/2023]
Abstract
Many physicochemical characteristics significantly influence the adjuvant effect of micro/nanoparticles; one critical factor is the kinetics of antigen exposure to the immune system by particle-adjuvanted vaccines. Here, we investigated how various antigen-nanoparticle formulations impacted antigen exposure to the immune system and the resultant antigen-specific immune responses. We formulated antigen with poly(lactic-co-glycolic acid) (PLGA) nanoparticles by encapsulating antigen within nanoparticles or by simply mixing soluble antigen with the nanoparticles. Our results indicated that the combined formulation (composed of antigen encapsulated in nanoparticles and antigen mixed with nanoparticles) induced more powerful antigen-specific immune responses than each single-component formulation. Mice immunized with the combined vaccine formulation displayed enhanced induction of antigen-specific IgG antibodies with high avidity, increased cytokine secretion by splenocytes, and improved generation of memory T cell. Enhanced immune responses elicited by the combined vaccine formulation might be attributed to the antigen-depot effect at the injection site, effective provision of both adequate initial antigen exposure and long-term antigen persistence, and efficient induction of dendritic cell (DC) activation and follicular helper T cell differentiation in draining lymph nodes. Understanding the effect of antigen-nanoparticle formulations on the resultant immune responses might have significant implications for rational vaccine design.
Collapse
Affiliation(s)
- Weifeng Zhang
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Lianyan Wang
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Yuan Liu
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaoming Chen
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qi Liu
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jilei Jia
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Tingyuan Yang
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Shaohui Qiu
- National Institutes for Food and Drug Control, Beijing 100050, PR China
| | - Guanghui Ma
- National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
| |
Collapse
|
13
|
Bergmann-Leitner ES, Leitner WW. Adjuvants in the Driver's Seat: How Magnitude, Type, Fine Specificity and Longevity of Immune Responses Are Driven by Distinct Classes of Immune Potentiators. Vaccines (Basel) 2014; 2:252-96. [PMID: 26344620 PMCID: PMC4494256 DOI: 10.3390/vaccines2020252] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/20/2014] [Accepted: 03/28/2014] [Indexed: 12/16/2022] Open
Abstract
The mechanism by which vaccine adjuvants enhance immune responses has historically been considered to be the creation of an antigen depot. From here, the antigen is slowly released and provided to immune cells over an extended period of time. This "depot" was formed by associating the antigen with substances able to persist at the injection site, such as aluminum salts or emulsions. The identification of Pathogen-Associated Molecular Patterns (PAMPs) has greatly advanced our understanding of how adjuvants work beyond the simple concept of extended antigen release and has accelerated the development of novel adjuvants. This review focuses on the mode of action of different adjuvant classes in regards to the stimulation of specific immune cell subsets, the biasing of immune responses towards cellular or humoral immune response, the ability to mediate epitope spreading and the induction of persistent immunological memory. A better understanding of how particular adjuvants mediate their biological effects will eventually allow them to be selected for specific vaccines in a targeted and rational manner.
Collapse
Affiliation(s)
- Elke S Bergmann-Leitner
- US Military Malaria Research Program, Malaria Vaccine Branch, 503 Robert Grant Ave, 3W65, Silver Spring, MD 20910, USA.
| | - Wolfgang W Leitner
- Division on Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 6610 Rockledge Drive, Bethesda, MD 20892, USA.
| |
Collapse
|
14
|
Savage DJ, Liu X, Curley SA, Ferrari M, Serda RE. Porous silicon advances in drug delivery and immunotherapy. Curr Opin Pharmacol 2013; 13:834-41. [PMID: 23845260 DOI: 10.1016/j.coph.2013.06.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 12/31/2022]
Abstract
Biomedical applications of porous silicon include drug delivery, imaging, diagnostics and immunotherapy. This review summarizes new silicon particle fabrication techniques, dynamics of cellular transport, advances in the multistage vector approach to drug delivery, and the use of porous silicon as immune adjuvants. Recent findings support superior therapeutic efficacy of the multistage vector approach over single particle drug delivery systems in mouse models of ovarian and breast cancer. With respect to vaccine development, multivalent presentation of pathogen-associated molecular patterns on the particle surface creates powerful platforms for immunotherapy, with the porous matrix able to carry both antigens and immune modulators.
Collapse
Affiliation(s)
- David J Savage
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, Houston, TX 77030, USA; MD Anderson Cancer Center, Department of Surgical Oncology, 1515 Holcombe Blvd #444, Houston, TX, USA; The University of Texas Medical School at Houston, 6431 Fannin, Houston, TX, USA
| | | | | | | | | |
Collapse
|
15
|
Blanchfield JL, Shorter SK, Evavold BD. Monitoring the Dynamics of T Cell Clonal Diversity Using Recombinant Peptide:MHC Technology. Front Immunol 2013; 4:170. [PMID: 23840195 PMCID: PMC3699728 DOI: 10.3389/fimmu.2013.00170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/14/2013] [Indexed: 12/31/2022] Open
Abstract
The capacity to probe antigen specific T cells within the polyclonal repertoire has been revolutionized by the advent of recombinant peptide:MHC (pMHC) technology. Monomers and multimers of pMHC molecules can enrich for and identify antigen specific T cells to elucidate the contributions of T cell frequency, localization, and T cell receptor (TCR) affinity during immune responses. Two-dimensional (2D) measurements of TCR–pMHC interactions are at the forefront of this field because the biological topography is replicated such that TCR and pMHC are membrane anchored on opposing cells, allowing for biologically pertinent measures of TCR antigen specificity and diversity. 2D measurements of TCR-pMHC kinetics have also demonstrated increased fidelity compared to three-dimensional surface plasmon resonance data and are capable of detecting T cell affinities that are below the detection level of most pMHC multimers. Importantly, 2D techniques provide a platform to evaluate T cell affinity and antigen specificity against multiple protein epitopes within the polyclonal repertoire directly ex vivo from sites of ongoing immune responses. This review will discuss how antigen specific pMHC molecules, with a focus on 2D technologies, can be used as effective tools to evaluate the range of TCR affinities that comprise an immune response and more importantly how the breadth of affinities determine functional outcome against a given exposure to antigen.
Collapse
Affiliation(s)
- J Lori Blanchfield
- Department of Microbiology and Immunology, Emory University, Atlanta, GA , USA
| | | | | |
Collapse
|
16
|
Abstract
Elevated understanding and respect for the relevance of the immune system in cancer development and therapy has led to increased development of immunotherapeutic regimens that target existing cancer cells and provide long-term immune surveillance and protection from cancer recurrence. This review discusses using particles as immune adjuvants to create vaccines and to augment the anticancer effects of conventional chemotherapeutics. Several particle prototypes are presented, including liposomes, polymer nanoparticles, and porous silicon microparticles, the latter existing as either single- or multiparticle platforms. The benefits of using particles include immune-cell targeting, codelivery of antigens and immunomodulatory agents, and sustained release of the therapeutic payload. Nanotherapeutic-based activation of the immune system is dependent on both intrinsic particle characteristics and on the immunomodulatory cargo, which may include danger signals known as pathogen-associated molecular patterns and cytokines for effector-cell activation.
Collapse
Affiliation(s)
- Rita Elena Serda
- Department of Nanomedicine, The Methodist Hospital Research Institute, Houston, TX 77030, USA.
| |
Collapse
|
17
|
Baumgartner CK, Yagita H, Malherbe LP. A TCR affinity threshold regulates memory CD4 T cell differentiation following vaccination. THE JOURNAL OF IMMUNOLOGY 2012; 189:2309-17. [PMID: 22844120 DOI: 10.4049/jimmunol.1200453] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Diverse Ag-specific memory TCR repertoires are essential for protection against pathogens. Subunit vaccines that combine peptide or protein Ags with TLR agonists are very potent at inducing T cell immune responses, but their capacity to elicit stable and diverse memory CD4 T cell repertoires has not been evaluated. In this study, we examined the evolution of a complex Ag-specific population during the transition from primary effectors to memory T cells after peptide or protein vaccination. Both vaccination regimens induced equally diverse effector CD4 TCR repertoires, but peptide vaccines skewed the memory CD4 TCR repertoire toward high-affinity clonotypes whereas protein vaccines maintained low-affinity clonotypes in the memory compartment. CD27-mediated signaling was essential for the maintenance of low-affinity clonotypes after protein vaccination but was not sufficient to promote their survival following peptide vaccination. The rapid culling of the TCR repertoire in peptide-immunized mice coincided with a prolonged proliferation phase during which low-affinity clonotypes disappeared despite exhibiting no sign of enhanced apoptosis. Our study reveals a novel affinity threshold for memory CD4 T cell differentiation following vaccination and suggests a role for nonapoptotic cell death in the regulation of CD4 T cell clonal selection.
Collapse
|
18
|
Reorienting our view of particle-based adjuvants for subunit vaccines. Proc Natl Acad Sci U S A 2012; 109:999-1000. [PMID: 22308523 DOI: 10.1073/pnas.1120993109] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
|
19
|
Abstract
Vaccines against microbial diseases have improved the health of millions of people. In the next decade and beyond, many conceptual and technological scientific advances offer extraordinary opportunities to expand the portfolio of immunisations against viral and bacterial diseases and to pioneer the first vaccines against human parasitic and fungal diseases. Scientists in the public and private sectors are motivated as never before to bring about these innovations in immunisation. Many societal factors threaten to compromise realisation of the public health gains that immunisation can achieve in the next decade and beyond--understanding these factors is imperative. Vaccines are typically given to healthy individuals and safety issues loom high on the list of public concerns. The public needs to regain confidence in immunisation and trust the organisations responsible for the research, development, and implementation of vaccines. In the past, by use of a judicious amalgam of knowledge and empiricism, successful vaccines were largely developed by microbiologists who identified antigens that induced immune responses to conserved pathogen components. In the future, vaccines need to be developed against deadly diseases for which this strategy is often not feasible because of the extensive antigenic variability of relevant pathogens. High microbial diversity means that immunity after natural infection is often ineffective for prevention of disease on subsequent exposure, for example in HIV infection and malaria. Additionally, vaccines need to be generated to protect the people who are most vulnerable because of age or underlying diseases. Thus, in the future, a much deeper understanding of the immunological challenges--including the diversifying role of host genetics and environmental factors, leading perhaps to more personalised approaches-will be the touchstone for rational design and development of adjuvants that result in novel safe and effective vaccines.
Collapse
Affiliation(s)
- E Richard Moxon
- University of Oxford Department of Paediatrics, John Radcliffe Hospital, Oxford, UK
| | | |
Collapse
|
20
|
van den Biggelaar AHJ, Pomat W, Bosco A, Phuanukoonnon S, Devitt CJ, Nadal-Sims MA, Siba PM, Richmond PC, Lehmann D, Holt PG. Pneumococcal conjugate vaccination at birth in a high-risk setting: no evidence for neonatal T-cell tolerance. Vaccine 2011; 29:5414-20. [PMID: 21645573 PMCID: PMC3146700 DOI: 10.1016/j.vaccine.2011.05.065] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 05/19/2011] [Accepted: 05/20/2011] [Indexed: 01/13/2023]
Abstract
Concerns about the risk of inducing immune deviation-associated “neonatal tolerance” as described in mice have restricted the widespread adoption of neonatal vaccination. The aim of this study was to demonstrate the immunological feasibility of neonatal pneumococcal conjugate vaccination (PCV) which could potentially protect high-risk infants in resource poor countries against severe pneumococcal disease and mortality in the early critical period of life. Papua New Guinean infants were randomized to be vaccinated with the 7-valent PCV (7vPCV) at birth, 1 and 2 months (neonatal group, n = 104) or at 1, 2 and 3 months of age (infant group, n = 105), or to not receive 7vPCV at all (control group, n = 109). Analysis of vaccine responses at 3 and 9 months of age demonstrated persistently higher type-1 (IFN-γ) and type-2 (IL-5 and IL-13) T-cell responses to the protein carrier CRM197 and IgG antibody titres to 7vPCV serotypes in children vaccinated with 7vPCV according to either schedule as compared to unvaccinated children. In a comprehensive immuno-phenotypic analysis at 9 months of age, no differences in the quantity or quality of vaccine-specific T cell memory responses were found between neonatal vaccinations versus children given their first PCV dose at one month. Hospitalization rates in the first month of life did not differ between children vaccinated with PCV at birth or not. These findings demonstrate that neonatal 7vPCV vaccination is safe and not associated with immunological tolerance. Neonatal immunisation schedules should therefore be considered in high-risk areas where this may result in improved vaccine coverage and the earliest possible protection against pneumococcal disease and death.
Collapse
Affiliation(s)
- Anita H J van den Biggelaar
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, PO Box 855, West Perth WA 6872, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
The role of the IL-12 cytokine family in directing T-cell responses in oral candidosis. Clin Dev Immunol 2010; 2011:697340. [PMID: 20981280 PMCID: PMC2963117 DOI: 10.1155/2011/697340] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/03/2010] [Indexed: 12/24/2022]
Abstract
Candida albicans is an opportunistic fungal pathogen that normally exists as a harmless commensal in humans. In instances where host debilitation occurs, Candida can cause a range of clinical infections, and whilst these are primarily superficial, effecting mucosal membranes, systemic infections can develop in severely immunocompromised individuals. The mechanism of host immunity during commensal carriage of C. albicans has been intensively studied. In this paper, we present the most recent information concerning host recognition of C. albicans leading to cytokine production and the subsequent T-cell responses generated in response to C. albicans. Particular focus is given to the role of the IL-12 cytokine family including IL-12, IL-23, IL-27, and IL-35, in host immunity to Candida. CD4+ T-cells are considered crucial in the regulation of immunity and inflammation. In this regard, the role of Th1/2, helper cells, together with the recently identified Th17 and Treg cells in candidosis will be discussed. Understanding the detailed mechanisms that underlie host immunity to Candida not only will be of benefit in terms of the infections caused by this organism but could also be exploited in the development of therapeutic interventions for other diseases.
Collapse
|
22
|
Abstract
Protective immunity against a variety of infections depends on the amplification and differentiation of rare naïve antigen-specific CD4 and CD8 T cells. Recent evidence indicates that the clonotypic composition of the responding T-cell compartment has a critical role in the immune defense against pathogens. The present review compares and contrasts how naive CD4 and CD8 T cells recognize their cognate antigen, and discusses the factors that regulate the genesis and maintenance of the CD4 and CD8 T-cell receptor repertoire diversity.
Collapse
|