Ex vivo lymphocyte phenotyping during Plasmodium falciparum sporozoite immunization in humans.
Parasite Immunol
; 37(11): 590-8, 2015 Nov.
Article
en En
| MEDLINE
| ID: mdl-26363409
Immunization of malaria-naïve volunteers under chemoprophylaxis with Plasmodium falciparum sporozoites (CPS) efficiently and reproducibly induces sterile protection and thus constitutes an excellent model to study protective immune responses against malaria. Here, we performed the first longitudinal assessment of lymphocyte activation and differentiation kinetics during sporozoite immunization in 15 volunteers by ex vivo lymphocyte flow cytometry analysis. Both CD4 and CD8 T cells as well as γδT cells, NK cells and CD3+ CD56+ cells showed increased activation and proliferation following immunization. Transient induction of the transcription factor T-bet and the cytotoxic molecule granzyme B indicated a role of Th1 responses and cytotoxic T cells in CPS-induced immunity. The absolute number of γδT cells as well as the proportion of granzyme B-containing γδT cells showed a significant and sustained increase. Regulatory T-cell (Treg) proliferation was significantly higher after the second immunization in subjects subsequently not protected against challenge infection. These findings indicate an important role for γδT cells, Th1 and cytotoxic responses in whole sporozoite immunization with a possibly suppressive role of Tregs.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasmodium falciparum
/
Malaria Falciparum
/
Vacunas contra la Malaria
/
Esporozoítos
Tipo de estudio:
Clinical_trials
/
Prognostic_studies
Límite:
Adult
/
Animals
/
Humans
Idioma:
En
Revista:
Parasite Immunol
Año:
2015
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Reino Unido