Sr. Costa et al., T cell response of asymptomatic Leishmania chagasi infected subjects to recombinant leishmania antigens, MEM I OSW C, 94(3), 1999, pp. 367-370
In areas of Leishmania chagasi transmission the ability to control leishman
ia infection is associated with IFN-gamma In visceral leishmaniasis down-re
gulation of T cell responses is mediated by interleukin-10 (IL-10). In this
study we evaluated the lymphoproliferative response, IFN-gamma and IL-10 p
roduction on lymphocyte cultures stimulated with recombinant leishmania ant
igens in subjects with asymptomatic L. chagasi infection. There was a stati
stically significant difference in the lymphoproliferative response of the
subjects with asymptomatic infection as compared to patients with visceral
leishmaniasis and healthy subjects with respect to crude antigens (p<0.01),
gp-63 (p<0.05) and hsp-70 (p<0.01), as well as between asymptomatic L. cha
gasi infected subjects and patients with visceral leishmaniasis with respec
t to the response to all antigens tested. The IFN-gamma production observed
in the group with asymptomatic infection with all the three recombinant an
tigens tested was higher (p<0.01) than that observed in patients with visce
ral leishmaniasis and in healthy subjects. Furthermore, in individuals with
asymptomatic infection, IL-IO levels in cultures stimulated with recombina
nt antigens were very low This study shows that lymphocytes from individual
s with asymptomatic L. chagasi infection are able to recognize recombinant
leishmania antigens with production of a cytokine that is associated with l
eishmania killing.