Title
Long-lasting humoral and cellular immune responses elicited by immunization with recombinant chimeras of the Plasmodium vivax circumsporozoite protein
Date Issued
17 April 2014
Access level
metadata only access
Resource Type
journal article
Author(s)
Almeida A.P.M.M.
Dias M.O.
Vieira C.d.A.F.
Gazzineli R.T.
Rodrigues M.M.
Fujiwara R.T.
Bruna-Romero O.
Universidade Federal de Minas Gerais
Publisher(s)
Elsevier BV
Abstract
The circumsporozoite protein (CSP), the most abundant surface antigen of sporozoites, has been extensively studied in different expression platforms as a vaccine candidate. Clinical trials have shown the necessity of broad and highly avid humoral immune responses together with high numbers of CSP-specific TCD4+ and TCD8+ cells, especially those producing IFN-γ, to induce protection. To this aim, we designed two distinct recombinant immunogens based on previously-described antigenic fragments of Plasmodium vivax CSP (PvCSP) to be used as vaccine candidates. The first one is a virus-like particle (VLP) comprising the repeat region of PvCSP (B and TCD4+ epitopes) within the loop of the hepatitis B virus core antigen (HBcAgPvCSP). The second one is a PvCSP multi-epitope polypeptide, rPvCSP-ME, designed based on antigenic regions of PvCSP recognized by lymphocytes of individuals from endemic areas.Mice immunized with 2 doses of these proteins, administered individually or combined and formulated in Montanide ISA 720 adjuvant, were able to induce strong effector and memory humoral responses with IgG titers ranging from 104 to 105 and avidity indexes toward full-length PvCSP reaching up to 66%, even 3 months after the last immunization. Furthermore, balanced Th1/Th2 responses were generated, as determined by titers of IgG subclasses and further confirmed by ELISPOT analyses, which detected that these vaccination protocols were able to elicit long-term IFN-γ and IL-2-secreting memory T-cells. Overall, these results show that our vaccine candidates generate, in mice, immune responses against regions within PvCSP that have been associated with protection against malaria in humans. © 2014 Elsevier Ltd.
Start page
2181
End page
2187
Volume
32
Issue
19
Language
English
OCDE Knowledge area
Parasitología
Inmunología
Subjects
Scopus EID
2-s2.0-84897115959
PubMed ID
Source
Vaccine
ISSN of the container
0264410X
Sponsor(s)
Funding text
We are grateful to the members of the Interdisciplinary Laboratory of Medical Investigation from the Faculty of Medicine, UFMG for their suggestions and wet laboratory support. We are also grateful to Ronaldo Alves Pinto Nagem for technical support. This work was supported in part by: (i) the Brazilian National Council for Scientific and Technological Development (CNPq project 479070/2004-0-Universal ). C.C-O, R. T. G., M.M.R, R.T.F. and O.B-R are research fellows from CNPq, (ii) the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG, projects 602/04/Universal and CBB – APQ-01490-08/Universal ) and the National Institute of Science and Technology for Vaccines (INCTV/CNPq/FAPEMIG) . A.P.M.M.A received FAPEMIG and MEC/CAPES scholarships.
Sources of information:
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Scopus