Different antibody- and cytokine-mediated responses to Plasmodium falciparum parasite in two sympatric ethnic tribes living in Mali

Functional deficit of T regulatory cells in Fulani, an ethnic group with low susceptibility to Plasmodium falciparum malaria

“…In contrast, gene expression of FOXP3 and CTLA4, two important genes related to the mechanisms of immune tolerance mediated by Treg, was markedly lower in Fulani than in Mossi. These results are in agreement with previous reports showing a more efficient TH1 and TH2 response toward P. falciparum antigens in this group (25). The reduced expression of FOXP3 and CTLA4 found in PBMC from Fulani, compared with sympatric Mossi, directly involves the activity of Treg, key agents of immune regulation (11,26).…”

Ethnic differences in susceptibility to malaria: What have we learned from immuno-epidemiological studies in West Africa?

“…Numerous studies have clearly demonstrated interethnic differences in susceptibility and in immune responses to malaria. The Fulani have lower infection rates, fewer clinical episodes and stronger humoral responses to various P. falciparum antigens compared to sympatric ethnic groups (Modiano et al, 1998;Farouk et al, 2005a). The higher immune reactivity to malarial antigens in the Fulani supports the notion that immunogenetic factors involved in the regulation of humoral and/or other immune responses contribute to decreased malaria susceptibility.…”

“…The higher incidence of spleen enlargement in the Fulani might reflect a hyper immune reactivity of this secondary lymphoid organ (Bereczky et al, 2006;Vafa et al, 2009a;Alkadarou et al, 2013), a hypothesis supported by several studies which consistently show that the Fulani mount a more robust humoral immune response, as reflected by increased titers of anti-plasmodial antibodies (Modiano et al, 1998(Modiano et al, , 1999Bolad et al, 2005;Farouk et al, 2005a;Vafa et al, 2009a). The levels of malaria blood-stage antibodies anti-AMA1 and anti-MSP1 were significantly increased in Fulani, suggesting the higher specific humoral responses against AMA1 and MSP1 in this ethnic group (Dolo et al, 2012a).…”

Regulatory T cells in malaria – friend or foe?

“…geographically overlapping) in Burkina-Faso suggests that the Fulani people, who are much less susceptible to clinical malaria [54] than non-Fulanis and are known to make very strong anti-malarial antibody responses [55], have defective T reg as well as deficits in TGF-b and TGF-b-R expression [56]. The authors conclude that lack of T reg activity might facilitate control of parasitemia; however, the crosssectional design of the study does not allow causality to be assumed, and an alternative interpretation of the data could be that the low level of T reg activity is the result of -rather than the cause of -lower levels of prior malaria exposure due to carriage of other protective genetic traits.…”