1
|
Kumar R, Kumar P. Yeast-based vaccines: New perspective in vaccine development and application. FEMS Yeast Res 2019; 19:5298404. [PMID: 30668686 DOI: 10.1093/femsyr/foz007] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/18/2019] [Indexed: 12/11/2022] Open
Abstract
In presently licensed vaccines, killed or attenuated organisms act as a source of immunogens except for peptide-based vaccines. These conventional vaccines required a mass culture of associated or related organisms and long incubation periods. Special requirements during storage and transportation further adds to the cost of vaccine preparations. Availability of complete genome sequence, well-established genetic, inherent natural adjuvant and non-pathogenic nature of yeast species viz. Saccharomyces cerevisiae, Pichia pastoris makes them an ideal model system for the development of vaccines both for public health and for on-farm consumption. In this review, we compile the work in this emerging field during last two decades with major emphases on S. cerevisiae and P. pastoris which are routinely used worldwide for expression of heterologous proteins with therapeutic value against infectious diseases along with possible use in cancer therapy. We also pointed towards the developments in use of whole recombinant yeast, yeast surface display and virus-like particles as a novel strategy in the fight against infectious diseases and cancer along with other aspects including suitability of yeast in vaccines preparations, yeast cell wall component as an immune stimulator or modulator and present status of yeast-based vaccines in clinical trials.
Collapse
Affiliation(s)
- Ravinder Kumar
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Piyush Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, Maharashtra, India
| |
Collapse
|
2
|
Younis S, Faber BW, Kocken CHM, Remarque EJ. Identification of adjuvants for clinical trials performed with Plasmodium falciparum AMA1 in rabbits. BMC Immunol 2019; 20:25. [PMID: 31362695 PMCID: PMC6664700 DOI: 10.1186/s12865-019-0307-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 07/18/2019] [Indexed: 11/20/2022] Open
Abstract
Background In this study, seven adjuvants were compared for use with Plasmodium falciparum DiCo-Apical Membrane Antigen 1 (Pf-DiCo-AMA1), with the aim to identify an ideal adjuvant which yields high antibody titres and potentially broadens the responses in clinical trials. The following adjuvant formulations were evaluated: SE, SE-GLA, Liposomes, Liposomes-GLA, CoVaccine HT™, ImSaVac-P and ImSaVac-P o/w. The study was performed in rabbits, which were immunized with FVO-AMA1 in combination with one of the seven adjuvants. Antibody levels (humoral responses) and functional activity of the antibodies induced against malaria vaccine candidate AMA1 were evaluated. Thus, in this study the ideal adjuvant is expected to induce high functional antibody levels, a long-lived response, and a broad cross-strain activity. Results AMA1 formulated in all adjuvants was immunogenic. However, the magnitude of the immune responses differed between the seven adjuvants. The highest IgG levels were observed for the CoVaccine HT™ group, this was statistically significant for all four AMA1 variants versus all other adjuvant groups. No differences were observed in the breadth of the humoral response, i.e., increased recognition of AMA1 variants. Also, Growth Inhibition Activity (GIA) for both Plasmodium falciparum strains (FCR3 – homologous to FVO AMA1 protein and NF54 – heterologous to FVO AMA1 protein) were significantly higher in the CoVaccine HT™ group as compared to the other adjuvant groups. Conclusions In brief, all seven vaccine – adjuvant formulations were immunogenic. The magnitude of the immune responses differed between the seven adjuvants. No statistically significant differences were observed in the breadth of the humoral response, nor in longevity of the response. Nevertheless, AMA1 formulated in CoVaccine HT™ appeared as the best adjuvant for use in clinical trials. Electronic supplementary material The online version of this article (10.1186/s12865-019-0307-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sumera Younis
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Bart W Faber
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Clemens H M Kocken
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Edmond J Remarque
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands.
| |
Collapse
|
3
|
Younis SY, Barnier-Quer C, Heuking S, Sommandas V, Brunner L, Vd Werff N, Dubois P, Friede M, Kocken C, Collin N, Remarque E. Down selecting adjuvanted vaccine formulations: a comparative method for harmonized evaluation. BMC Immunol 2018; 19:6. [PMID: 29386070 PMCID: PMC5793412 DOI: 10.1186/s12865-018-0245-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 01/24/2018] [Indexed: 11/16/2022] Open
Abstract
Background The need for rapid and accurate comparison of panels of adjuvanted vaccine formulations and subsequent rational down selection, presents several challenges for modern vaccine development. Here we describe a method which may enable vaccine and adjuvant developers to compare antigen/adjuvant combinations in a harmonized fashion. Three reference antigens: Plasmodium falciparum apical membrane antigen 1 (AMA1), hepatitis B virus surface antigen (HBsAg), and Mycobacterium tuberculosis antigen 85A (Ag85A), were selected as model antigens and were each formulated with three adjuvants: aluminium oxyhydroxide, squalene-in-water emulsion, and a liposome formulation mixed with the purified saponin fraction QS21. Results The nine antigen/adjuvant formulations were assessed for stability and immunogenicity in mice in order to provide benchmarks against which other formulations could be compared, in order to assist subsequent down selection of adjuvanted vaccines. Furthermore, mouse cellular immune responses were analyzed by measuring IFN-γ and IL-5 production in splenocytes by ELISPOT, and humoral responses were determined by antigen-specific ELISA, where levels of total IgG, IgG1, IgG2b and IgG2c in serum samples were determined. Conclusions The reference antigens and adjuvants described in this study, which span a spectrum of immune responses, are of potential use as tools to act as points of reference in vaccine development studies. The harmonized methodology described herein may be used as a tool for adjuvant/antigen comparison studies.
Collapse
Affiliation(s)
- Sumera Y Younis
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | | | - Simon Heuking
- Vaccine Formulation Laboratory, University of Lausanne, Epalinges, Switzerland
| | - Vinod Sommandas
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Livia Brunner
- Vaccine Formulation Laboratory, University of Lausanne, Epalinges, Switzerland
| | - Nicole Vd Werff
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Patrice Dubois
- Vaccine Formulation Laboratory, University of Lausanne, Epalinges, Switzerland
| | | | - Clemens Kocken
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Nicolas Collin
- Vaccine Formulation Laboratory, University of Lausanne, Epalinges, Switzerland
| | - Ed Remarque
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands.
| |
Collapse
|
4
|
Vulliez-Le Normand B, Saul FA, Hoos S, Faber BW, Bentley GA. Cross-reactivity between apical membrane antgen 1 and rhoptry neck protein 2 in P. vivax and P. falciparum: A structural and binding study. PLoS One 2017; 12:e0183198. [PMID: 28817634 PMCID: PMC5560645 DOI: 10.1371/journal.pone.0183198] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/31/2017] [Indexed: 02/03/2023] Open
Abstract
Malaria, a disease endemic in many tropical and subtropical regions, is caused by infection of the erythrocyte by the apicomplexan parasite Plasmodium. Host-cell invasion is a complex process but two Plasmodium proteins, Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck protein complex (RON), play a key role. AMA1, present on the surface of the parasite, binds tightly to the RON2 component of the RON protein complex, which is inserted into the erythrocyte membrane during invasion. Blocking the AMA1-RON2 interaction with antibodies or peptides inhibits invasion, underlining its importance in the Plasmodium life cycle and as a target for therapeutic strategies. We describe the crystal structure of the complex formed between AMA1 from P. vivax (PvAMA1) and a peptide derived from the externally exposed region of P. vivax RON2 (PvRON2sp1), and of the heterocomplex formed between P. falciparum AMA1 (PfAMA1) and PvRON2sp1. Binding studies show that the affinity of PvRON2sp1 for PvAMA1 is weaker than that previously reported for the PfRON2sp1-PfAMA1 association. Moreover, while PvRON2sp1 shows strong cross-reactivity with PfAMA1, PfRON2sp1 displays no detectable interaction with PvAMA1. The structures show that the equivalent residues PvRON2-Thr2055 and PfRON2-Arg2041 largely account for this pattern of reactivity.
Collapse
Affiliation(s)
- Brigitte Vulliez-Le Normand
- Institut Pasteur, Unité de Microbiologie Structurale, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique, UMR 3528, Université Paris Diderot, Sorbonne Paris Cité, Microbiologie Structurale, Paris, France
| | - Frederick A. Saul
- Institut Pasteur, Plate-forme de Cristallographie, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique UMR 3528, Paris, France
| | - Sylviane Hoos
- Institut Pasteur, Plate-Forme de Biophysique Moléculaire, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique UMR 3528, Paris, France
| | - Bart W. Faber
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Graham A. Bentley
- Institut Pasteur, Unité d’Immunologie Structurale, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique, URA 2185, Paris, France
- * E-mail:
| |
Collapse
|
5
|
Generation, characterization and immunogenicity of a novel chimeric recombinant protein based on Plasmodium vivax AMA-1 and MSP1 19. Vaccine 2017; 35:2463-2472. [PMID: 28341111 DOI: 10.1016/j.vaccine.2017.03.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/10/2017] [Accepted: 03/07/2017] [Indexed: 11/22/2022]
Abstract
Plasmodium vivax is the most widely distributed malaria species and the most prevalent species of malaria in America and Asia. Vaccine development against P. vivax is considered a priority in the global program for the eradication of malaria. Earlier studies have characterized the Apical Membrane Antigen 1 (AMA-1) ectodomain and the C-terminal region (19kDa) of the Merozoite Surface Protein 1 (MSP-1) of P. vivax as immunodominant antigens. Based on this characterization, we designed a chimeric recombinant protein containing both merozoite immunodominant domains (PvAMA166-MSP119). The recombinant PvAMA166-MSP119 was successfully expressed in Pichia pastoris and used to immunize two different mouse strains (BALB/c and C57BL/6) in the presence of the Poly (I:C) as an adjuvant. Immunization with the chimeric protein induced high antibody titers against both proteins in both strains of mice as detected by ELISA. Antisera also recognized the native proteins expressed on the merozoites of mature P. vivax schizonts. Moreover, this antigen was able to induce IFN-gamma-secreting cells in C57BL/6 mice. These findings indicate that this novel yeast recombinant protein containing PvAMA166 and PvMSP119 is advantageous, because of improved antibody titers and cellular immune response. Therefore, this formulation should be further developed for pre-clinical trials in non-human primates as a potential candidate for a P. vivax vaccine.
Collapse
|
6
|
Strain-transcending immune response generated by chimeras of the malaria vaccine candidate merozoite surface protein 2. Sci Rep 2016; 6:20613. [PMID: 26865062 PMCID: PMC4749986 DOI: 10.1038/srep20613] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/08/2016] [Indexed: 12/16/2022] Open
Abstract
MSP2 is an intrinsically disordered protein that is abundant on the merozoite surface and essential to the parasite Plasmodium falciparum. Naturally-acquired antibody responses to MSP2 are biased towards dimorphic sequences within the central variable region of MSP2 and have been linked to naturally-acquired protection from malaria. In a phase IIb study, an MSP2-containing vaccine induced an immune response that reduced parasitemias in a strain-specific manner. A subsequent phase I study of a vaccine that contained both dimorphic forms of MSP2 induced antibodies that exhibited functional activity in vitro. We have assessed the contribution of the conserved and variable regions of MSP2 to the generation of a strain-transcending antibody response by generating MSP2 chimeras that included conserved and variable regions of the 3D7 and FC27 alleles. Robust anti-MSP2 antibody responses targeting both conserved and variable regions were generated in mice, although the fine specificity and the balance of responses to these regions differed amongst the constructs tested. We observed significant differences in antibody subclass distribution in the responses to these chimeras. Our results suggest that chimeric MSP2 antigens can elicit a broad immune response suitable for protection against different strains of P. falciparum.
Collapse
|
7
|
Paul J, Jensen S, Dukart A, Cornelissen G. Optimization of a preparative multimodal ion exchange step for purification of a potential malaria vaccine. J Chromatogr A 2014; 1366:38-44. [DOI: 10.1016/j.chroma.2014.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/09/2014] [Accepted: 09/12/2014] [Indexed: 11/29/2022]
|
8
|
Vaccines to combat river blindness: expression, selection and formulation of vaccines against infection with Onchocerca volvulus in a mouse model. Int J Parasitol 2014; 44:637-46. [PMID: 24907553 DOI: 10.1016/j.ijpara.2014.04.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 01/21/2023]
Abstract
Human onchocerciasis is a neglected tropical disease caused by Onchocerca volvulus and an important cause of blindness and chronic disability in the developing world. Although mass drug administration of ivermectin has had a profound effect on control of the disease, additional tools are critically needed including the need for a vaccine against onchocerciasis. The objectives of the present study were to: (i) select antigens with known vaccine pedigrees as components of a vaccine; (ii) produce the selected vaccine antigens under controlled conditions, using two expression systems and in one laboratory and (iii) evaluate their vaccine efficacy using a single immunisation protocol in mice. In addition, we tested the hypothesis that joining protective antigens as a fusion protein or in combination, into a multivalent vaccine, would improve the ability of the vaccine to induce protective immunity. Out of eight vaccine candidates tested in this study, Ov-103, Ov-RAL-2 and Ov-CPI-2M were shown to reproducibly induce protective immunity when administered individually, as fusion proteins or in combination. Although there was no increase in the level of protective immunity induced by combining the antigens into one vaccine, these antigens remain strong candidates for inclusion in a vaccine to control onchocerciasis in humans.
Collapse
|
9
|
Curd RD, Birdsall B, Kadekoppala M, Ogun SA, Kelly G, Holder AA. The structure of Plasmodium yoelii merozoite surface protein 119, antibody specificity and implications for malaria vaccine design. Open Biol 2014; 4:130091. [PMID: 24403012 PMCID: PMC3909271 DOI: 10.1098/rsob.130091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 12/06/2013] [Indexed: 11/12/2022] Open
Abstract
Merozoite surface protein 1 (MSP1) has been identified as a target antigen for protective immune responses against asexual blood stage malaria, but effective vaccines based on MSP1 have not been developed so far. We have modified the sequence of Plasmodium yoelii MSP119 (the C-terminal region of the molecule) and examined the ability of the variant proteins to bind protective monoclonal antibodies and to induce protection by immunization. In parallel, we examined the structure of the protein and the consequences of the amino acid changes. Naturally occurring sequence polymorphisms reduced the binding of individual protective antibodies, indicating that they contribute to immune evasion, but immunization with these variant proteins still provided protective immunity. One variant that resulted in the localized distortion of a loop close to the N-terminus of MSP119 almost completely ablated protection by immunization, indicating the importance of this region of MSP119 as a target for protective immunity and in vaccine development.
Collapse
Affiliation(s)
- Rachel D. Curd
- Divisions of Parasitology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Berry Birdsall
- Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Madhusudan Kadekoppala
- Divisions of Parasitology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Solabomi A. Ogun
- Divisions of Parasitology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Geoffrey Kelly
- NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Anthony A. Holder
- Divisions of Parasitology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| |
Collapse
|
10
|
Faber BW, Younis S, Remarque EJ, Rodriguez Garcia R, Riasat V, Walraven V, van der Werff N, van der Eijk M, Cavanagh DR, Holder AA, Thomas AW, Kocken CHM. Diversity covering AMA1-MSP119 fusion proteins as malaria vaccines. Infect Immun 2013; 81:1479-90. [PMID: 23429538 PMCID: PMC3648017 DOI: 10.1128/iai.01267-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/13/2013] [Indexed: 11/20/2022] Open
Abstract
To overcome polymorphism in the malaria vaccine candidate Plasmodium falciparum apical membrane antigen 1 (PfAMA1), fusion protein chimeras comprised of three diversity-covering (DiCo) PfAMA1 molecules (D1, D2, and D3) and two allelic variants of the C-terminal 19-kDa region of merozoite surface protein 1 (MSP119) (variants M1 and M2) were generated. A mixture of fusion proteins (D1M1/D2M2D3) and the D1M1D2M2D3 fusion were compared to a single-unit mixture (D1/D2/D3/M1) in an immunological study in groups of rabbits. Following immunization, titers of antibodies (Abs) against four naturally occurring PfAMA1 alleles were high for all groups, as were growth inhibition assay (GIA) levels against two antigenically distinct laboratory parasite strains. Fusion of AMA1 to MSP119 did not suppress levels of antibodies against the AMA1 component. In addition, the breadth of antibody responses was unaffected. Anti-AMA1 antibodies were largely responsible for parasite growth inhibition, as shown in reversal-of-inhibition experiments by adding competing AMA1 antigen. For all groups, titration of the MSP119 antigen into the GIA led to only a small decrease in parasite inhibition, although titers of antibodies against MSP119 were increased 15-fold for the groups immunized with fusion proteins. GIA with affinity-purified anti-MSP119 antibodies showed that the 50% inhibitory concentrations of the anti-MSP119 antibody preparations were in the same order of magnitude for all animals tested, leading to the conclusion that fusing MSP119 to PfAMA1 leads to a small but significant increase in functional antibody levels. This study shows that combination of multiple vaccine candidates in fusion proteins may lead to improved characteristics of the vaccine.
Collapse
Affiliation(s)
- Bart W. Faber
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Sumera Younis
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Edmond J. Remarque
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | | | - Vanessa Riasat
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Vanessa Walraven
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Nicole van der Werff
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Marjolein van der Eijk
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - David R. Cavanagh
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Anthony A. Holder
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Alan W. Thomas
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| | - Clemens H. M. Kocken
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands
| |
Collapse
|
11
|
Williams AR, Douglas AD, Miura K, Illingworth JJ, Choudhary P, Murungi LM, Furze JM, Diouf A, Miotto O, Crosnier C, Wright GJ, Kwiatkowski DP, Fairhurst RM, Long CA, Draper SJ. Enhancing blockade of Plasmodium falciparum erythrocyte invasion: assessing combinations of antibodies against PfRH5 and other merozoite antigens. PLoS Pathog 2012; 8:e1002991. [PMID: 23144611 PMCID: PMC3493472 DOI: 10.1371/journal.ppat.1002991] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 09/11/2012] [Indexed: 02/01/2023] Open
Abstract
No vaccine has yet proven effective against the blood-stages of Plasmodium falciparum, which cause the symptoms and severe manifestations of malaria. We recently found that PfRH5, a P. falciparum-specific protein expressed in merozoites, is efficiently targeted by broadly-neutralizing, vaccine-induced antibodies. Here we show that antibodies against PfRH5 efficiently inhibit the in vitro growth of short-term-adapted parasite isolates from Cambodia, and that the EC50 values of antigen-specific antibodies against PfRH5 are lower than those against PfAMA1. Since antibody responses elicited by multiple antigens are speculated to improve the efficacy of blood-stage vaccines, we conducted detailed assessments of parasite growth inhibition by antibodies against PfRH5 in combination with antibodies against seven other merozoite antigens. We found that antibodies against PfRH5 act synergistically with antibodies against certain other merozoite antigens, most notably with antibodies against other erythrocyte-binding antigens such as PfRH4, to inhibit the growth of a homologous P. falciparum clone. A combination of antibodies against PfRH4 and basigin, the erythrocyte receptor for PfRH5, also potently inhibited parasite growth. This methodology provides the first quantitative evidence that polyclonal vaccine-induced antibodies can act synergistically against P. falciparum antigens and should help to guide the rational development of future multi-antigen vaccines. Malaria is the most devastating parasitic disease of humans, resulting in an estimated 0.6–1 million deaths per year. The symptoms of malaria are caused when merozoites invade and replicate within red blood cells, and therefore a vaccine which induced antibodies that effectively prevent this invasion process would be a major step towards the control of the disease. However, development of such a vaccine has proved extremely challenging. A major roadblock has been the probable need for extremely high levels of antibodies to achieve vaccine efficacy. We have now shown that antibodies against the merozoite protein PfRH5 are able to neutralize the invasion of red blood cells by malaria parasites at concentrations that are significantly lower than for antibodies against PfAMA1 – the previous leading blood-stage malaria vaccine target. This neutralization was observed in both laboratory-adapted parasite lines and in five different parasite isolates from Cambodian patients with malaria. Furthermore, we found that by combining antibodies against PfRH5 with antibodies against certain other merozoite antigens we could achieve synergistic neutralization of parasites, further lowering the amount of antibody needed to be induced by a vaccine. The development of vaccines encoding the PfRH5 antigen in combination with a second target may thus be the best way to achieve the long-sought after goal of an efficacious blood-stage malaria vaccine. Moreover, the methodology described here to assess the ability of antibodies against different targets to synergize should greatly aid the future rational design of improved vaccine candidates.
Collapse
|
12
|
Remarque EJ, Roestenberg M, Younis S, Walraven V, van der Werff N, Faber BW, Leroy O, Sauerwein R, Kocken CHM, Thomas AW. Humoral immune responses to a single allele PfAMA1 vaccine in healthy malaria-naïve adults. PLoS One 2012; 7:e38898. [PMID: 22768052 PMCID: PMC3387192 DOI: 10.1371/journal.pone.0038898] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/14/2012] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Plasmodium falciparum: apical membrane antigen 1 (AMA1) is a candidate malaria vaccine antigen expressed on merozoites and sporozoites. The polymorphic nature of AMA1 may compromise vaccine induced protection. The humoral response induced by two dosages (10 and 50 µg) of a single allele AMA1 antigen (FVO) formulated with Alhydrogel, Montanide ISA 720 or AS02 was investigated in 47 malaria-naïve adult volunteers. Volunteers were vaccinated 3 times at 4 weekly intervals and serum samples obtained four weeks after the third immunization were analysed for (i) Antibody responses to various allelic variants, (ii) Domain specificity, (iii) Avidity, (iv) IgG subclass levels, by ELISA and (v) functionality of antibody responses by Growth Inhibition Assay (GIA). About half of the antibodies induced by vaccination cross reacted with heterologous AMA1 alleles. The choice of adjuvant determined the magnitude of the antibody response, but had only a marginal influence on specificity, avidity, domain recognition or subclass responses. The highest antibody responses were observed for AMA1 formulated with AS02. The Growth Inhibition Assay activity of the antibodies was proportional to the amount of antigen specific IgG and the functional capacity of the antibodies was similar for heterologous AMA1-expressing laboratory strains. TRIAL REGISTRATION ClinicalTrials.gov NCT00730782.
Collapse
|
13
|
Qian F, Reiter K, Zhang Y, Shimp RL, Nguyen V, Aebig JA, Rausch KM, Zhu D, Lambert L, Mullen GED, Martin LB, Long CA, Miller LH, Narum DL. Immunogenicity of self-associated aggregates and chemically cross-linked conjugates of the 42 kDa Plasmodium falciparum merozoite surface protein-1. PLoS One 2012; 7:e36996. [PMID: 22675476 PMCID: PMC3366955 DOI: 10.1371/journal.pone.0036996] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 04/11/2012] [Indexed: 12/04/2022] Open
Abstract
Self-associated protein aggregates or cross-linked protein conjugates are, in general, more immunogenic than oligomeric or monomeric forms. In particular, the immunogenicity in mice of a recombinant malaria transmission blocking vaccine candidate, the ookinete specific Plasmodium falciparum 25 kDa protein (Pfs25), was increased more than 1000-fold when evaluated as a chemical cross-linked protein-protein conjugate as compared to a formulated monomer. Whether alternative approaches using protein complexes improve the immunogenicity of other recombinant malaria vaccine candidates is worth assessing. In this work, the immunogenicity of the recombinant 42 kDa processed form of the P. falciparum merozoite surface protein 1 (MSP142) was evaluated as a self-associated, non-covalent aggregate and as a chemical cross-linked protein-protein conjugate to ExoProtein A, which is a recombinant detoxified form of Pseudomonas aeruginosa exotoxin A. MSP142 conjugates were prepared and characterized biochemically and biophysically to determine their molar mass in solution and stoichiometry, when relevant. The immunogenicity of the MSP142 self-associated aggregates, cross-linked chemical conjugates and monomers were compared in BALB/c mice after adsorption to aluminum hydroxide adjuvant, and in one instance in association with the TLR9 agonist CPG7909 with an aluminum hydroxide formulation. Antibody titers were assessed by ELISA. Unlike observations made for Pfs25, no significant enhancement in MSP142 specific antibody titers was observed for any conjugate as compared to the formulated monomer or dimer, except for the addition of the TLR9 agonist CPG7909. Clearly, enhancing the immunogenicity of a recombinant protein vaccine candidate by the formation of protein complexes must be established on an empirical basis.
Collapse
Affiliation(s)
- Feng Qian
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Department of Rheumatology and Immunology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Yanling Zhang
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Richard L. Shimp
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Vu Nguyen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Joan A. Aebig
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Kelly M. Rausch
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Daming Zhu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Lynn Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Gregory E. D. Mullen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Division of Imaging Sciences, School of Medicine, King’s College London, London, United Kingdom
| | - Laura B. Martin
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Novartis Vaccines Institute for Global Health S.r.l. (NVGH), Siena, Italy
| | - Carole A. Long
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Louis H. Miller
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - David L. Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail:
| |
Collapse
|
14
|
Plasmodium falciparum 19-kilodalton merozoite surface protein 1 (MSP1)-specific antibodies that interfere with parasite growth in vitro can inhibit MSP1 processing, merozoite invasion, and intracellular parasite development. Infect Immun 2011; 80:1280-7. [PMID: 22202121 DOI: 10.1128/iai.05887-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Merozoite surface protein 1 (MSP1) is a target for malaria vaccine development. Antibodies to the 19-kDa carboxy-terminal region referred to as MSP1(19) inhibit erythrocyte invasion and parasite growth, with some MSP1-specific antibodies shown to inhibit the proteolytic processing of MSP1 that occurs at invasion. We investigated a series of antibodies purified from rabbits immunized with MSP1(19) and AMA1 recombinant proteins for their ability to inhibit parasite growth, initially looking at MSP1 processing. Although significant inhibition of processing was mediated by several of the antibody samples, there was no clear relationship with overall growth inhibition by the same antibodies. However, no antibody samples inhibited processing but not invasion, suggesting that inhibition of MSP1 processing contributes to but is not the only mechanism of antibody-mediated inhibition of invasion and growth. Examining other mechanisms by which MSP1-specific antibodies inhibit parasite growth, we show that MSP1(19)-specific antibodies are taken up into invaded erythrocytes, where they persist for significant periods and result in delayed intracellular parasite development. This delay may result from antibody interference with coalescence of MSP1(19)-containing vesicles with the food vacuole. Antibodies raised against a modified recombinant MSP1(19) sequence were more efficient at delaying intracellular growth than those to the wild-type protein. We propose that antibodies specific for MSP1(19) can mediate inhibition of parasite growth by at least three mechanisms: inhibition of MSP1 processing, direct inhibition of invasion, and inhibition of parasite development following invasion. The balance between mechanisms may be modulated by modifying the immunogen used to induce the antibodies.
Collapse
|
15
|
Cowan GJM, Creasey AM, Dhanasarnsombut K, Thomas AW, Remarque EJ, Cavanagh DR. A malaria vaccine based on the polymorphic block 2 region of MSP-1 that elicits a broad serotype-spanning immune response. PLoS One 2011; 6:e26616. [PMID: 22073118 PMCID: PMC3202563 DOI: 10.1371/journal.pone.0026616] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 09/29/2011] [Indexed: 12/28/2022] Open
Abstract
Polymorphic parasite antigens are known targets of protective immunity to malaria, but this antigenic variation poses challenges to vaccine development. A synthetic MSP-1 Block 2 construct, based on all polymorphic variants found in natural Plasmodium falciparum isolates has been designed, combined with the relatively conserved Block 1 sequence of MSP-1 and expressed in E.coli. The MSP-1 Hybrid antigen has been produced with high yield by fed-batch fermentation and purified without the aid of affinity tags resulting in a pure and extremely thermostable antigen preparation. MSP-1 hybrid is immunogenic in experimental animals using adjuvants suitable for human use, eliciting antibodies against epitopes from all three Block 2 serotypes. Human serum antibodies from Africans naturally exposed to malaria reacted to the MSP-1 hybrid as strongly as, or better than the same serum reactivities to individual MSP-1 Block 2 antigens, and these antibody responses showed clear associations with reduced incidence of malaria episodes. The MSP-1 hybrid is designed to induce a protective antibody response to the highly polymorphic Block 2 region of MSP-1, enhancing the repertoire of MSP-1 Block 2 antibody responses found among immune and semi-immune individuals in malaria endemic areas. The target population for such a vaccine is young children and vulnerable adults, to accelerate the acquisition of a full range of malaria protective antibodies against this polymorphic parasite antigen.
Collapse
MESH Headings
- Adolescent
- Adult
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Protozoan/blood
- Antibodies, Protozoan/immunology
- Case-Control Studies
- Child
- Child, Preschool
- Cross-Sectional Studies
- Enzyme-Linked Immunosorbent Assay
- Female
- Fluorescent Antibody Technique, Indirect
- Humans
- Immunization
- Immunoblotting
- Immunoglobulin G/immunology
- Macaca mulatta
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/prevention & control
- Merozoite Surface Protein 1/immunology
- Mice
- Mice, Inbred DBA
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Rabbits
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Collapse
Affiliation(s)
- Graeme J. M. Cowan
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Alison M. Creasey
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Kelwalin Dhanasarnsombut
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Alan W. Thomas
- Biomedical Primate Research Center, Rijswijk, The Netherlands
| | | | - David R. Cavanagh
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
| |
Collapse
|
16
|
Tetteh KKA, Conway DJ. A polyvalent hybrid protein elicits antibodies against the diverse allelic types of block 2 in Plasmodium falciparum merozoite surface protein 1. Vaccine 2011; 29:7811-7. [PMID: 21820475 PMCID: PMC3195258 DOI: 10.1016/j.vaccine.2011.07.106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 07/18/2011] [Accepted: 07/23/2011] [Indexed: 01/20/2023]
Abstract
Merozoite surface protein 1 (MSP1) of Plasmodium falciparum has been implicated as an important target of acquired immunity, and candidate components for a vaccine include polymorphic epitopes in the N-terminal polymorphic block 2 region. We designed a polyvalent hybrid recombinant protein incorporating sequences of the three major allelic types of block 2 together with a composite repeat sequence of one of the types and N-terminal flanking T cell epitopes, and compared this with a series of recombinant proteins containing modular sub-components and similarly expressed in Escherichia coli. Immunogenicity of the full polyvalent hybrid protein was tested in both mice and rabbits, and comparative immunogenicity studies of the sub-component modules were performed in mice. The full hybrid protein induced high titre antibodies against each of the major block 2 allelic types expressed as separate recombinant proteins and against a wide range of allelic types naturally expressed by a panel of diverse P. falciparum isolates, while the sub-component modules had partial antigenic coverage as expected. This encourages further development and evaluation of the full MSP1 block 2 polyvalent hybrid protein as a candidate blood-stage component of a malaria vaccine.
Collapse
Affiliation(s)
- Kevin K A Tetteh
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
| | | |
Collapse
|
17
|
Kusi KA, Remarque EJ, Riasat V, Walraven V, Thomas AW, Faber BW, Kocken CHM. Safety and immunogenicity of multi-antigen AMA1-based vaccines formulated with CoVaccine HT™ and Montanide ISA 51 in rhesus macaques. Malar J 2011; 10:182. [PMID: 21726452 PMCID: PMC3142537 DOI: 10.1186/1475-2875-10-182] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/04/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increasing the breadth of the functional antibody response through immunization with Plasmodium falciparum apical membrane antigen 1 (PfAMA1) multi-allele vaccine formulations has been demonstrated in several rodent and rabbit studies. This study assesses the safety and immunogenicity of three PfAMA1 Diversity-Covering (DiCo) vaccine candidates formulated as an equimolar mixture (DiCo mix) in CoVaccine HT™ or Montanide ISA 51, as well as that of a PfAMA1-MSP1₁₉ fusion protein formulated in Montanide ISA 51. METHODS Vaccine safety in rhesus macaques was monitored by animal behaviour observation and assessment of organ and systemic functions through clinical chemistry and haematology measurements. The immunogenicity of vaccine formulations was assessed by enzyme-linked immunosorbent assays and in vitro parasite growth inhibition assays with three culture-adapted P. falciparum strains. RESULTS These data show that both adjuvants were well tolerated with only transient changes in a few of the chemical and haematological parameters measured. DiCo mix formulated in CoVaccine HT™ proved immunologically and functionally superior to the same candidate formulated in Montanide ISA 51. Immunological data from the fusion protein candidate was however difficult to interpret as four out of six immunized animals were non-responsive for unknown reasons. CONCLUSIONS The study highlights the safety and immunological benefits of DiCo mix as a potential human vaccine against blood stage malaria, especially when formulated in CoVaccine HT™, and adds to the accumulating data on the specificity broadening effects of DiCo mix.
Collapse
Affiliation(s)
- Kwadwo A Kusi
- Department of Parasitology, Biomedical Primate Research Centre, Postbox 3306, 2280 GH, Rijswijk, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
18
|
Anders RF. The case for a subunit vaccine against malaria. Trends Parasitol 2011; 27:330-4. [PMID: 21592861 DOI: 10.1016/j.pt.2011.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/15/2011] [Accepted: 04/15/2011] [Indexed: 11/28/2022]
Abstract
New technologies and some disillusionment with subunit vaccines has led to increased interest in the development of whole parasite vaccines for malaria. Instead, the current priority should be to build on the partial success of the recombinant protein sporozoite vaccine, RTS,S. There are many possible options for delivering a subunit vaccine but the simplest option, formulating recombinant proteins in an adjuvant, should be fully explored. Numerous options exist for inducing heightened immune responses and for tackling the problem of diversity, but development of recombinant protein subunit vaccines requires a more detailed knowledge of the conformation of the leading vaccine candidates.
Collapse
Affiliation(s)
- Robin F Anders
- Department of Biochemistry, La Trobe University, Victoria, Australia.
| |
Collapse
|
19
|
Martens S, Borchert SO, Faber BW, Cornelissen G, Luttmann R. Fully automated production of potential Malaria vaccines with Pichia pastoris in integrated processing. Eng Life Sci 2011. [DOI: 10.1002/elsc.201000163] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
20
|
New candidate vaccines against blood-stage Plasmodium falciparum malaria: prime-boost immunization regimens incorporating human and simian adenoviral vectors and poxviral vectors expressing an optimized antigen based on merozoite surface protein 1. Infect Immun 2010; 78:4601-12. [PMID: 20713623 DOI: 10.1128/iai.00315-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Although merozoite surface protein 1 (MSP-1) is a leading candidate vaccine antigen for blood-stage malaria, its efficacy in clinical trials has been limited in part by antigenic polymorphism and potentially by the inability of protein-in-adjuvant vaccines to induce strong cellular immunity. Here we report the design of novel vectored Plasmodium falciparum vaccines capable of overcoming such limitations. We optimized an antigenic insert comprising the four conserved blocks of MSP-1 fused to tandemly arranged sequences that represent both allelic forms of the dimorphic 42-kDa C-terminal region. Inserts were expressed by adenoviral and poxviral vectors and employed in heterologous prime-boost regimens. Simian adenoviral vectors were used in an effort to circumvent preexisting immunity to human adenoviruses. In preclinical studies these vaccines induced potent cellular immune responses and high-titer antibodies directed against MSP-1. The antibodies induced were found to have growth-inhibitory activity against dimorphic allelic families of P. falciparum. These vectored vaccines should allow assessment in humans of the safety and efficacy of inducing strong cellular as well as cross-strain humoral immunity to P. falciparum MSP-1.
Collapse
|
21
|
Detection of Plasmodium falciparum, P. vivax, P. ovale, and P. malariae merozoite surface protein 1-p19 antibodies in human malaria patients and experimentally infected nonhuman primates. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1631-8. [PMID: 20702658 DOI: 10.1128/cvi.00196-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Approximately 3.2 billion people live in areas where malaria is endemic, and WHO estimates that 350 to 500 million malaria cases occur each year worldwide. This high prevalence, and the high frequency of international travel, creates significant risk for the exportation of malaria to countries where malaria is not endemic and for the introduction of malaria organisms into the blood supply. Since all four human infectious Plasmodium species have been transmitted by blood transfusion, we sought to develop an enzyme-linked immunosorbent assay (ELISA) capable of detecting antibodies elicited by infection with any of these species. The merozoite surface protein 1 (MSP1), a P. falciparum and P. vivax vaccine candidate with a well-characterized immune response, was selected for use in the assay. The MSP1 genes from P. ovale and P. malariae were cloned and sequenced (L. Birkenmeyer, A. S. Muerhoff, G. Dawson, and S. M. Desai, Am. J. Trop. Med. Hyg. 82:996-1003, 2010), and the carboxyl-terminal p19 regions of all four species were expressed in Escherichia coli. Performance results from individual p19 ELISAs were compared to those of a commercial test (Lab 21 Healthcare Malaria enzyme immunoassay [EIA]). The commercial ELISA detected all malaria patients with P. falciparum or P. vivax infections, as did the corresponding species-specific p19 ELISAs. However, the commercial ELISA detected antibodies in 0/2 and 5/8 individuals with P. malariae and P. ovale infections, respectively, while the p19 assays detected 100% of individuals with confirmed P. malariae or P. ovale infections. In experimentally infected nonhuman primates, the use of MSP1-p19 antigens from all four species resulted in the detection of antibodies within 2 to 10 weeks postinfection. Use of MSP1-p19 antigens from all four Plasmodium species in a single immunoassay would provide significantly improved efficacy compared to existing tests.
Collapse
|
22
|
Birkenmeyer L, Muerhoff AS, Dawson GJ, Desai SM. Isolation and characterization of the MSP1 genes from Plasmodium malariae and Plasmodium ovale. Am J Trop Med Hyg 2010; 82:996-1003. [PMID: 20519591 DOI: 10.4269/ajtmh.2010.09-0022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The merozoite surface protein 1 (MSP1) is the principal surface antigen of the blood stage form of the Plasmodium parasite. Antibodies recognizing MSP1 are frequently detected following Plasmodium infection, making this protein a significant component of malaria vaccines and diagnostic tests. Although the MSP1 gene sequence has been reported for Plasmodium falciparum and Plasmodium vivax, this gene has not been identified for the other two major human-infectious species, Plasmodium malariae and Plasmodium ovale. MSP1 genes from these two species were isolated from Cameroon blood donor samples. The genes are similar in size to known MSP1 genes and encode proteins with interspecies conserved domains homologous to those identified in other Plasmodium species. Sequence and phylogenetic analysis of all available Plasmodium MSP1 amino acid sequences clearly shows that the Po and Pm MSP1 sequences are truly unique within the Plasmodium genus and not simply Pf or Pv variants.
Collapse
Affiliation(s)
- Larry Birkenmeyer
- Abbott Diagnostics, Infectious Diseases R&D, Dept. 09NB, Bldg. AP20, 100 Abbott Park Road, Abbott Park, IL 60064-6015, USA.
| | | | | | | |
Collapse
|
23
|
Pasini EM, Kirkegaard M, Mortensen P, Mann M, Thomas AW. Deep-coverage rhesus red blood cell proteome: a first comparison with the human and mouse red blood cell. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2010; 8 Suppl 3:s126-39. [PMID: 20606743 PMCID: PMC2897199 DOI: 10.2450/2010.020s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
BACKGROUND Macaques are the closest evolutionary relatives of humans routinely used in basic and applied biomedical research. Their genetic, physiological, immunological and metabolic similarity to humans, second only to that of the great apes, makes them invaluable models of human disease. These similarities also mean that macaques are often the only experimental models available for evaluating increasingly specific drugs in development, and as a proof-of-concept bridge can help reduce the numbers of compounds that fail in clinical pharmaceutical research. In vertebrates, red blood cells (RBCs) diseases are frequently severe as their role as sole gas transporter makes them indispensable to survival; much research has therefore focused on an in-depth understanding of the functioning of the RBC. RBCs also host malaria, babesia and other parasites. Recently, we presented an in-depth proteome for the human RBC and a comparative human/mouse RBC proteome. MATERIAL AND METHODS Here, we present directly comparable data for the human, mouse and rhesus RBC proteomes. All proteins were identified, validated and categorized in terms of sub-cellular localization, protein family and function and, in comparison with the human and mouse RBC, were classified as orthologues, family-related or unique. Splice isoforms were identified and polypeptides migrating with anomalous apparent molecular weights were grouped into putatively ubiquitinylated or partially degraded complexes. RESULTS AND DISCUSSION Overall there was close concordance between mouse, human and rhesus proteomes, confirming the unexpected RBC complexity. Several novel findings in the human and mouse proteomes have been confirmed here. This comparison sheds light on several open issues in RBC biology and provides a departure point for more comprehensive understanding of RBC function.
Collapse
Affiliation(s)
- Erica M. Pasini
- Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Morten Kirkegaard
- Center for Experimental Bioinformatics, University of Southern Denmark, Odense, Denmark
| | - Peter Mortensen
- Center for Experimental Bioinformatics, University of Southern Denmark, Odense, Denmark
| | - Matthias Mann
- Center for Experimental Bioinformatics, University of Southern Denmark, Odense, Denmark
- Dept. of Proteomics and Signal Transduction, Max-Planck Institute for Biochemistry, Martinsried, Germany
| | - Alan W. Thomas
- Biomedical Primate Research Centre, Rijswijk, The Netherlands
- Correspondence: Alan Thomas, Dept. Parasitology, Biomedical Primate Research Centre, Lange Kleiweg 139, 2288 GJ Rijswijk, The Netherlands, E-mail:
| |
Collapse
|
24
|
Humoral immune response to mixed PfAMA1 alleles; multivalent PfAMA1 vaccines induce broad specificity. PLoS One 2009; 4:e8110. [PMID: 19956619 PMCID: PMC2779588 DOI: 10.1371/journal.pone.0008110] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 11/04/2009] [Indexed: 11/19/2022] Open
Abstract
Apical Membrane Antigen 1 (AMA1), a merozoite protein essential for red cell invasion, is a candidate malaria vaccine component. Immune responses to AMA1 can protect in experimental animal models and antibodies isolated from AMA1-vaccinated or malaria-exposed humans can inhibit parasite multiplication in vitro. The parasite is haploid in the vertebrate host and the genome contains a single copy of AMA1, yet on a population basis a number of AMA1 molecular surface residues are polymorphic, a property thought to be primarily as a result of selective immune pressure. After immunisation with AMA1, antibodies more effectively inhibit strains carrying homologous AMA1 genes, suggesting that polymorphism may compromise vaccine efficacy. Here, we analyse induction of broad strain inhibitory antibodies with a multi-allele Plasmodium falciparum AMA1 (PfAMA1) vaccine, and determine the relative importance of cross-reactive and strain-specific IgG fractions by competition ELISA and in vitro parasite growth inhibition assays. Immunisation of rabbits with a PfAMA1 allele mixture yielded an increased proportion of antibodies to epitopes common to all vaccine alleles, compared to single allele immunisation. Competition ELISA with the anti-PfAMA1 antibody fraction that is cross-reactive between FVO and 3D7 AMA1 alleles showed that over 80% of these common antibodies were shared with other PfAMA1 alleles. Furthermore, growth inhibition assays revealed that for any PfAMA1 allele (FVO or 3D7), the cross-reactive fraction alone, on basis of weight, had the same functional capacity on homologous parasites as the total affinity-purified IgGs (cross-reactive+strain-specific). By contrast, the strain-specific IgG fraction of either PfAMA1 allele showed slightly less inhibition of red cell invasion by homologous strains. Thus multi-allele immunisation relatively increases the levels of antibodies to common allele epitopes. This explains the broadened cross inhibition of diverse malaria parasites, and suggests multi-allele approaches warrant further clinical investigation.
Collapse
|
25
|
The carboxy-terminus of merozoite surface protein 1: structure, specific antibodies and immunity to malaria. Parasitology 2009; 136:1445-56. [PMID: 19627632 DOI: 10.1017/s0031182009990515] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYOver the last 30 years, evidence has been gathered suggesting that merozoite surface protein 1 (MSP1) is a target of protective immunity against malaria. In a variety of experimental approaches usingin vitromethodology, animal models and sero-epidemiological techniques, the importance of antibody against MSP1 has been established but we are still finding out what are the mechanisms involved. Now that clinical trials of MSP1 vaccines are underway and the early results have been disappointing, it is increasingly clear that we need to know more about the mechanisms of immunity, because a better understanding will highlight the limitations of our current assays and identify the improvements required. Understanding the structure of MSP1 will help us design and engineer better antigens that are more effective than the first generation of vaccine candidates. This review is focused on the carboxy-terminus of MSP1.
Collapse
|
26
|
Malkin E, Hu J, Li Z, Chen Z, Bi X, Reed Z, Dubovsky F, Liu J, Wang Q, Pan X, Chen T, Giersing B, Xu Y, Kang X, Gu J, Shen Q, Tucker K, Tierney E, Pan W, Long C, Cao Z. A phase 1 trial of PfCP2.9: an AMA1/MSP1 chimeric recombinant protein vaccine for Plasmodium falciparum malaria. Vaccine 2008; 26:6864-73. [PMID: 18930094 DOI: 10.1016/j.vaccine.2008.09.081] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/18/2008] [Accepted: 09/26/2008] [Indexed: 11/16/2022]
Abstract
Apical Membrane Antigen 1 (AMA1) and Merozoite Surface Protein 1 (MSP1) were produced as a recombinant fusion protein and formulated with the adjuvant Montanide ISA 720 with the aim of replicating the structure present in the parasite protein. A previous trial with this construct demonstrated the vaccine was safe and immunogenic but was associated with injection site reactogenicity. This Phase 1a dose-escalating, double blind, randomized, controlled trial of PfCP2.9/Montanide ISA 720 was conducted to evaluate alternative dose levels and vaccination schedules, with a pre-formulated vaccine that had undergone more in-depth and frequent quality control and stability analysis. The trial was conducted in seventy healthy Chinese malaria-naïve volunteers between January 2006 and January 2007. The objective was to assess the safety, reactogenicity and immunogenicity of 5, 20 and 50microg of PfCP2.9/ISA 720 under 2 different schedules. The most common adverse event was injection site tenderness (53%). The frequency and severity of adverse events was similar in both vaccination schedules. Antibody responses were induced and remained elevated throughout the study in volunteers receiving vaccine (p<0.001). Although high antibody titers as measured by ELISA to the PfCP2.9 immunogen were observed, biological function of these antibodies was not reflected by the in vitro inhibition of parasite growth, and there was limited recognition of fixed parasites in an immunofluorescence assay. At all three dose levels and both schedules, this formulation of PfCP2.9/ISA 720 is well tolerated, safe and immunogenic; however no functional activity against the parasite was observed.
Collapse
|
27
|
Heterologous expression of plasmodial proteins for structural studies and functional annotation. Malar J 2008; 7:197. [PMID: 18828893 PMCID: PMC2567985 DOI: 10.1186/1475-2875-7-197] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 10/01/2008] [Indexed: 11/10/2022] Open
Abstract
Malaria remains the world's most devastating tropical infectious disease with as many as 40% of the world population living in risk areas. The widespread resistance of Plasmodium parasites to the cost-effective chloroquine and antifolates has forced the introduction of more costly drug combinations, such as Coartem®. In the absence of a vaccine in the foreseeable future, one strategy to address the growing malaria problem is to identify and characterize new and durable antimalarial drug targets, the majority of which are parasite proteins. Biochemical and structure-activity analysis of these proteins is ultimately essential in the characterization of such targets but requires large amounts of functional protein. Even though heterologous protein production has now become a relatively routine endeavour for most proteins of diverse origins, the functional expression of soluble plasmodial proteins is highly problematic and slows the progress of antimalarial drug target discovery. Here the status quo of heterologous production of plasmodial proteins is presented, constraints are highlighted and alternative strategies and hosts for functional expression and annotation of plasmodial proteins are reviewed.
Collapse
|
28
|
Faber BW, Remarque EJ, Kocken CHM, Cheront P, Cingolani D, Xhonneux F, Jurado M, Haumont M, Jepsen S, Leroy O, Thomas AW. Production, quality control, stability and pharmacotoxicity of cGMP-produced Plasmodium falciparum AMA1 FVO strain ectodomain expressed in Pichia pastoris. Vaccine 2008; 26:6143-50. [PMID: 18804135 DOI: 10.1016/j.vaccine.2008.08.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 08/06/2008] [Accepted: 08/31/2008] [Indexed: 10/21/2022]
Abstract
Plasmodium falciparum apical membrane antigen 1 (PfAMA1) is a leading asexual blood stage vaccine candidate for malaria. In preparation for clinical trials, PfAMA1 ectodomain (amino acid 25-545, FVO strain) was produced in Pichia pastoris by 35L scale fed batch fermentation under current Good Manufacturing Practice (cGMP). Fermentation was followed by a three-step chromatographic purification procedure resulting in a yield of 5.8g of purified protein. As judged by size exclusion chromatography, the cGMP-product comprised >95% PfAMA1 monomer, the remainder being predominantly PfAMA1 dimer. In SDS-PAGE two main bands of 68 and 70kDa and some minor bands were evident. Under reducing conditions a site of limited proteolytic cleavage within a disulphide bonded region became evident; less than 15% of the protein had this internal cleavage. By mass-spectrometric analysis, all bands analyzed in overloaded SDS-PAGE gels comprised PfAMA1 derived products. The protein was quantitatively bound by immobilized 4G2, a monoclonal antibody reactive with a reduction sensitive conformational determinant. The lyophilized product was stable for over 1 year. Immunopotency did not diminish, and storage did not lead to alterations in the behaviour of the protein upon formulation with adjuvants selected for Phase I clinical evaluation. These formulations also showed no pharmacotoxicity in rabbits. The final product conformed to preset criteria and was judged suitable for use in human clinical trials.
Collapse
Affiliation(s)
- Bart W Faber
- Department of Parasitology, Biomedical Primate Research Center, Lange Kleiweg 139, 2288 GJ Rijswijk, The Netherlands
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Arnot DE, Cavanagh DR, Remarque EJ, Creasey AM, Sowa MPK, Morgan WD, Holder AA, Longacre S, Thomas AW. Comparative testing of six antigen-based malaria vaccine candidates directed toward merozoite-stage Plasmodium falciparum. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1345-55. [PMID: 18550731 PMCID: PMC2546674 DOI: 10.1128/cvi.00172-08] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 05/29/2008] [Indexed: 11/20/2022]
Abstract
Immunogenicity testing of Plasmodium falciparum antigens being considered as malaria vaccine candidates was undertaken in rabbits. The antigens compared were recombinant baculovirus MSP-1(19) and five Pichia pastoris candidates, including two versions of MSP-1(19), AMA-1 (domains I and II), AMA-1+MSP-1(19), and fused AMA-1/MSP-1(19)). Animals were immunized with equimolar amounts of each antigen, formulated in Montanide ISA720. The specificities and titers of antibodies were compared using immunofluorescence assays and enzyme-linked immunosorbent assay (ELISA). The antiparasite activity of immunoglobulin G (IgG) in in vitro cultures was determined by growth inhibition assay, flow cytometry, lactate dehydrogenase assay, and microscopy. Baculovirus MSP-1(19) immunizations produced the highest parasite-specific antibody titers in immunofluorescence assays. In ELISAs, baculovirus-produced MSP-1(19) induced more antibodies than any other single MSP-1(19) immunogen and three times more MSP-1(19) specific antibodies than the AMA-1/MSP-1(19) fusion. Antibodies induced by baculovirus MSP-1(19) gave the highest levels of growth inhibition in HB3 and 3D7 parasite cultures, followed by AMA-1+MSP-1(19) and the AMA-1/MSP-1(19) fusion. With the FCR3 isolate (homologous to the AMA-1 construct), antibodies to the three AMA-1-containing candidates gave the highest levels of growth inhibition at high IgG concentrations, but antibodies to baculovirus MSP-1(19) inhibited as well or better at lower IgG concentrations. The two P. pastoris-produced MSP-1(19)-induced IgGs conferred the lowest growth inhibition. Comparative analysis of immunogenicity of vaccine antigens can be used to prioritize candidates before moving to expensive GMP production and clinical testing. The assays used have given discriminating readouts but it is not known whether any of them accurately reflect clinical protection.
Collapse
Affiliation(s)
- David E Arnot
- Centre for Medical Parasitology, Institute for International Health, Immunology and Microbiology, University of Copenhagen, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
A diversity-covering approach to immunization with Plasmodium falciparum apical membrane antigen 1 induces broader allelic recognition and growth inhibition responses in rabbits. Infect Immun 2008; 76:2660-70. [PMID: 18378635 DOI: 10.1128/iai.00170-08] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum apical membrane antigen 1 (PfAMA1), a candidate malaria vaccine, is polymorphic. This polymorphism is believed to be generated predominantly under immune selection pressure and, as a result, may compromise attempts at vaccination. Alignment of 355 PfAMA1 sequences shows that around 10% of the 622 amino acid residues can vary between alleles and that linkages between polymorphic residues occur. Using this analysis, we have designed three diversity-covering (DiCo) PfAMA1 sequences that take account of these linkages and, when taken together, on average incorporate 97% of amino acid variability observed. For each of the three DiCo sequences, a synthetic gene was constructed and used to transform the methylotrophic yeast Pichia pastoris, allowing recombinant expression. All three DiCo proteins were reactive with the reduction-sensitive monoclonal antibody 4G2, suggesting the DiCo sequences had conformations similar to those of naturally occurring PfAMA1. Rabbits were immunized with FVO strain PfAMA1 or with the DiCo proteins either individually or as a mixture. Antibody titers and the ability to inhibit parasite growth in vitro were determined. Animals immunized with the DiCo mix performed similarly to animals immunized with FVO AMA1 when measured against FCR3 strain parasites but outperformed animals immunized with FVO AMA1 when assessed against other strains. The levels of growth inhibition (approximately 70%) induced by the mix of three DiCo proteins were comparable for FVO, 3D7, and HB3, suggesting that a considerable degree of diversity in AMA1 is adequately covered. This suggests that vaccines based upon the DiCo mix approach provide a broader functional immunity than immunization with a single allele.
Collapse
|
31
|
Remarque EJ, Faber BW, Kocken CHM, Thomas AW. Apical membrane antigen 1: a malaria vaccine candidate in review. Trends Parasitol 2008; 24:74-84. [PMID: 18226584 DOI: 10.1016/j.pt.2007.12.002] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 10/31/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
Abstract
Apical membrane antigen 1 (AMA1) is a micronemal protein of apicomplexan parasites that appears to be essential during the invasion of host cells. Immune responses to Plasmodium AMA1 can have profound parasite-inhibitory effects, both as measured in vitro and in animal challenge models, suggesting AMA1 as a potential vaccine component. However, AMA1 is polymorphic, probably as a result of immune selection operating on an important target of naturally occurring immunity. The current understanding of AMA1 will be presented, particularly in relation to the vaccine potential of AMA1 and the approaches being taken towards clinical development.
Collapse
Affiliation(s)
- Edmond J Remarque
- Department of Parasitology, Biomedical Primate Research Centre, 2280 GH Rijswijk, The Netherlands
| | | | | | | |
Collapse
|