Development of cellular immune responses to Plasmodium falciparum blood stage antigens from birth to 36 months of age in Cameroon.
Naturally acquired immunity to Plasmodium falciparum is related to immune system that changes during normal development and ageing. The effects of repeated infections during the early life on the maturation of the immune system are still unknown. Elucidation of these effects is of considerable interest given that malaria originates high mortality, especially during the first years of life. We conducted a cohort study to identify naturally acquired immune responses to P. falciparum. Cellular responses of Cameroonian neonates from birth to 36 months of age were evaluated every 6 months by cell proliferation and cytokines (IFN-gamma, IL-2 and IL-4) production after in vitro culture in the presence of schizont extract and Pf155/RESA peptides. Data were analyzed by a multiple correspondence analysis (MCA) exhibiting three main findings. Firstly, the lack of time-dependant evolution of specific immune pathways recruitment in the response to a given antigen, no antigen inducing a specific mode of response at a given time-point. Secondly, most of the data variability was expressed by IFN-gamma and IL-4 productions, and the major variation of the immune response with age involved this change in IFN-gamma production. Thirdly, the age-related immune response evolution is characterized by the acquisition of the capacity to mount a IFN-gamma response, a transient phase during which children produce a high IL-4 response, and the fast vanishing of the dominance of the IL-2 response. These results suggest that P. falciparum specific immune responses are first oriented towards a Th2-type of response, and later switch to Th1-type of response.
Le Hesran
Jean-Yves
JY
Institut de Recherche pour le Développement (IRD), UR 010, Mother and Health in the Tropics, Faculté de Pharmacie, 75006 Paris, France. Jean-Yves.Lehesran@ird.fr
Fiévet
Nadine
N
Thioulouse
Jean
J
Personne
Philippe
P
Maubert
Bertrand
B
M'bidias
Samuel
S
Etye'ale
Daniel
D
Cot
Michel
M
Deloron
Philippe
P
D000375:Aging / Q000276:immunology*; D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood* / Q000276:immunology*; D002163:Cameroon; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D016778:Malaria, Falciparum / Q000276:immunology*; D010963:Plasmodium falciparum / Q000378:metabolism*; D018417:Th1 Cells / Q000378:metabolism; D018418:Th2 Cells / Q000378:metabolism
D000953:Antigens, Protozoan