Hw. Ghalib et al., INTERLEUKIN-10 PRODUCTION CORRELATES WITH PATHOLOGY IN HUMAN LEISHMANIA-DONOVANI INFECTIONS, The Journal of clinical investigation, 92(1), 1993, pp. 324-329
We have found that an important Th2 cytokine, IL-10, is produced by ti
ssues from patients acutely infected with Leishmania donovani. In all
individuals tested, IL-10 mRNA production was increased in lymph nodes
taken during acute disease over that observed in postacute samples. I
n contrast, both pre- and posttreatment lymph nodes had readily detect
ed MRNA for IFN-gamma and IL-2. A down-regulating effect of IL-10 on l
eishmania-induced proliferative responses was demonstrated when Hu rIL
-10 was added to cultures of PBMC from clinically cured individuals. P
BMC from individuals with acute visceral leishmaniasis responded to st
imulation with leishmania lysate by producing IL-10 MRNA. Simultaneous
ly cultured PBMC collected from the same patients after successful che
motherapy produced no detectable Ll-10 MRNA after leishmania antigen s
timulation. Neutralizing anti-IL-10 mAb added to PBMC from patients wi
th acute visceral leishmaniasis markedly increased the proliferative r
esponse to leishmania lysate. Finally, we observed mRNA for IL-10 and
IFN-gamma concurrently in a lesion from a patient with post-kala-azar
dermal leishmaniasis (PKDL). These results indicate the production of
IL-10 during L. donovani infection, and suggest a role for this cytoki
ne in the regulation of immune responsiveness during visceral leishman
iasis.