scholarly journals Induction of T Helper Type 1 and 2 Responses to 19-Kilodalton Merozoite Surface Protein 1 in Vaccinated Healthy Volunteers and Adults Naturally Exposed to Malaria

2002 ◽  
Vol 70 (3) ◽  
pp. 1417-1421 ◽  
Author(s):  
Edwin A. M. Lee ◽  
Dupeh R. Palmer ◽  
Katie L. Flanagan ◽  
William H. H. Reece ◽  
Kennedy Odhiambo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Interleukin 4 ◽  
T Cell Epitopes ◽  
Humoral Immune ◽  
Merozoite Surface Protein 1 ◽  
Humoral Immune Responses ◽  
Human Volunteers ◽  
The Tropics

ABSTRACT Plasmodium falciparum malaria is a major cause of death in the tropics. The 19-kDa subunit of P. falciparum merozoite surface protein 1 (MSP-119), a major blood stage vaccine candidate, is the target of cellular and humoral immune responses in animals and humans. In this phase I trial of MSP-119, immunization of nonexposed human volunteers with either of the two allelic forms of recombinant MSP-119 induced high levels of antigen-specific Th1 (gamma interferon) and Th2 (interleukin 4 [IL-4] and IL-10) type lymphokines. The adjustment of the antigen dose and number of immunizations regulated the level of specificity of immune responses and Th1/Th2 bias of responses induced by vaccination. Novel conserved and allelic T-cell epitopes which induced cross-strain immune responses were identified. Importantly, responses to many of these novel epitopes were also present in adults exposed to malaria, both in east (Kenya) and west Africa (The Gambia). These data suggest that epitope-specific naturally acquired MSP-119 immune responses in endemic populations can be boosted by vaccination.

scholarly journals Genetic diversity and immunogenicity of the merozoite surface protein 1 C-terminal 19-kDa fragment of Plasmodium ovale imported from Africa into China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Qinwen Xu ◽  
Sihong Liu ◽  
Kokouvi Kassegne ◽  
Bo Yang ◽  
Jiachen Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Immune Responses ◽  
Expression System ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Plasmodium Ovale ◽  
Merozoite Surface Protein 1 ◽  
Proliferation Assays

Abstract Background Merozoite surface protein 1 (MSP1) plays an essential role in erythrocyte invasion by malaria parasites. The C-terminal 19-kDa region of MSP1 has long been considered one of the major candidate antigens for a malaria blood-stage vaccine against Plasmodium falciparum. However, there is limited information on the C-terminal 19-kDa region of Plasmodium ovale MSP1 (PoMSP119). This study aims to analyze the genetic diversity and immunogenicity of PoMSP119. Methods A total of 37 clinical Plasmodium ovale isolates including Plasmodium ovale curtisi and Plasmodium ovale wallikeri imported from Africa into China and collected during the period 2012–2016 were used. Genomic DNA was used to amplify P. ovale curtisi (poc) msp119 (pocmsp119) and P. ovale wallikeri (pow) msp119 (powmsp119) genes by polymerase chain reaction. The genetic diversity of pomsp119 was analyzed using the GeneDoc version 6 programs. Recombinant PoMSP119 (rPoMSP119)-glutathione S-transferase (GST) proteins were expressed in an Escherichia coli expression system and analyzed by western blot. Immune responses in BALB/c mice immunized with rPoMSP119-GST were determined using enzyme-linked immunosorbent assay. In addition, antigen-specific T cell responses were assessed by lymphocyte proliferation assays. A total of 49 serum samples from healthy individuals and individuals infected with P. ovale were used for the evaluation of natural immune responses by using protein microarrays. Results Sequences of pomsp119 were found to be thoroughly conserved in all the clinical isolates. rPoMSP119 proteins were efficiently expressed and purified as ~ 37-kDa proteins. High antibody responses in mice immunized with rPoMSP119-GST were observed. rPoMSP119-GST induced high avidity indexes, with an average of 92.57% and 85.32% for rPocMSP119 and rPowMSP119, respectively. Cross-reactivity between rPocMSP119 and rPowMSP119 was observed. Cellular immune responses to rPocMSP119 (69.51%) and rPowMSP119 (52.17%) induced in rPocMSP119- and rPowMSP119-immunized mice were found in the splenocyte proliferation assays. The sensitivity and specificity of rPoMSP119-GST proteins for the detection of natural immune responses in patients infected with P. ovale were 89.96% and 75%, respectively. Conclusions This study revealed highly conserved gene sequences of pomsp119. In addition, naturally acquired humoral immune responses against rPoMSP1 were observed in P. ovale infections, and high immunogenicity of rPoMSP119 in mice was also identified. These instructive findings should encourage further testing of PoMSP119 for rational vaccine design. Graphical abstract

Control of Cellular and Humoral Immune Responses by Peptides Containing T-cell Epitopes

1989 ◽  
Vol 54 (0) ◽  
pp. 497-504 ◽  
Author(s):  
M.T. Scherer ◽  
B.M.C. Chan ◽  
F. Ria ◽  
J.A. Smith ◽  
D.L. Perkins ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Epitopes ◽  
Humoral Immune ◽  
Humoral Immune Responses

scholarly journals Protection against Plasmodium chabaudi Malaria Induced by Immunization with Apical Membrane Antigen 1 and Merozoite Surface Protein 1 in the Absence of Gamma Interferon or Interleukin-4

2004 ◽  
Vol 72 (10) ◽  
pp. 5605-5612 ◽  
Author(s):  
James M. Burns ◽  
Patrick R. Flaherty ◽  
Payal Nanavati ◽  
William P. Weidanz
Keyword(s):  
Apical Membrane ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Plasmodium Chabaudi ◽  
Protective Antibody ◽  
Apical Membrane Antigen 1 ◽  
Immune Mechanisms ◽  
Merozoite Surface Protein 1

ABSTRACT Strategies to optimize formulations of multisubunit malaria vaccines require a basic knowledge of underlying protective immune mechanisms induced by each vaccine component. In the present study, we evaluated the contribution of antibody-mediated and cell-mediated immune mechanisms to the protection induced by immunization with two blood-stage malaria vaccine candidate antigens, apical membrane antigen 1 (AMA-1) and merozoite surface protein 1 (MSP-1). Immunologically intact or selected immunologic knockout mice were immunized with purified recombinant Plasmodium chabaudi AMA-1 (PcAMA-1) and/or the 42-kDa C-terminal processing fragment of P. chabaudi MSP-1 (MSP-142). The efficacy of immunization in each animal model was measured as protection against blood-stage P. chabaudi malaria. Immunization of B-cell-deficient JH −/− mice indicated that PcAMA-1 vaccine-induced immunity is largely antibody dependent. In contrast, JH −/− mice immunized with PcMSP-142 were partially protected against P. chabaudi malaria, indicating a role for protective antibody-dependent and antibody-independent mechanisms of immunity. The involvement of γδ T cells in vaccine-induced PcAMA-1 and/or PcMSP-142 protection was minor. Analysis of the isotypic profile of antigen-specific antibodies induced by immunization of immunologically intact mice revealed a dominant IgG1 response. However, neither interleukin-4 and the production of IgG1 antibodies nor gamma interferon and the production of IgG2a/c antibodies were essential for PcAMA-1 and/or PcMSP-142 vaccine-induced protection. Therefore, for protective antibody-mediated immunity, vaccine adjuvants and delivery systems for AMA-1- and MSP-1-based vaccines can be selected for their ability to maximize responses irrespective of IgG isotype or any Th1 versus Th2 bias in the CD4+-T-cell response.

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