Benznidazole treatment during early-indeterminate Chagas' disease shifted the cytokine expression by innate and adaptive immunity cells toward a type 1-modulated immune profile.
Trypanosoma cruzi-infected children was treated with benznidazole (Bz) during the early-indeterminate disease (E-IND) and the cytokine pattern of innate and adaptive immune compartments were evaluated prior to the treatment and 1 year after it. At first, we observed that the ex vivo cytokine profile of circulating leukocytes from E-IND (n = 6) resembled the one observed for healthy schoolchildren (n = 7). Additionally, in vitro stimulation with T. cruzi antigens drove the E-IND cytokine pattern toward a mixed immune profile with higher levels of IFN-gamma+, TNF-alpha+ and IL-4+ NK cells, increased numbers of IFN-gamma+, TNF-alpha+ and IL-10+ CD4+ T cells in addition to enhanced frequency of TNF-alpha+/IL-4+ CD19+ lymphocytes. Interestingly, upon T. cruzi antigen in vitro stimulation, E-IND CD8+ lymphocytes displayed a selective enhancement of IFN-gamma expression, accounting for a global type 1-modulated cytokine microenvironment. A shift toward a type 1-modulated profile was also the hallmark of Bz-treated children (E-IND(T)). In this context, despite the mixed overall ex vivo cytokine profile observed for NK and CD8+ T cells, increased ability of these leukocytes to produce IFN-gamma in response to T. cruzi antigens was reported. Most noteworthy was the IL-10 production evidenced at T lymphocytes, mainly CD4+ cells, as well as B lymphocytes, both ex vivo and upon antigen stimulation. Together, these findings gave evidence that NK cells and CD8+ T lymphocytes are the major sources of IFN-gamma, a pivotal cytokine for successful therapeutic response in human Chagas' disease. Moreover, our data have also brought additional information, pointing out IL-10 production by CD4+ cells and B lymphocytes, as the putative key element for parasite clearance in the absence of deleterious tissue damage.
Sathler-Avelar
R
R
Laboratório de Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil. avelar@cpqrr.fiocruz.br
Vitelli-Avelar
D M
DM
Massara
R L
RL
Borges
J D
JD
Lana
M
M
Teixeira-Carvalho
A
A
Dias
J C P
JC
Elói-Santos
S M
SM
Martins-Filho
O A
OA
D000293:Adolescent; D000818:Animals; D016022:Case-Control Studies; D014355:Chagas Disease / Q000276:immunology* / Q000628:therapy; D002648:Child; D016207:Cytokines / Q000097:blood*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007113:Immunity, Innate; D008137:Longitudinal Studies; D008297:Male; D009593:Nitroimidazoles / Q000627:therapeutic use*; D014349:Trypanosoma cruzi / Q000276:immunology*
D016207:Cytokines; D009593:Nitroimidazoles; C009999:benzonidazole