Leishmania donovani infection of a susceptible host results in CD4+ T-cell apoptosis and decreased Th1 cytokine production.
The disease visceral leishmaniasis is caused by a protozoan parasite, Leishmania donovani and is characterized by depressed cell-mediated immunity (CMI) and unhindered parasite growth in a susceptible host. The opposite trend is observed in a resistant host. However, the mechanism of this loss of CMI during the progressive disease is unknown as yet. In this report, we demonstrate that more than 40% of CD4+ T cells from a susceptible host undergo apoptosis resulting in a significant decrease in interleukin (IL)-2 and interferon (IFN)-gamma secretion, leaving IL-4 secretion unaffected. These changes are not apparent in the case of CD4+ T cells derived from a resistant host. The data reported here suggest that experimental Leishmania donovani infection leads to selective deletion of the IL-2 and IFN-gamma-secreting cells but not Th2-like cells in a susceptible but not a resistant host.
Das
G
G
National Center for Cell Sciences, Ganeshkhind, Pune, India.
Vohra
H
H
Rao
K
K
Saha
B
B
Mishra
G C
GC
D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis*; D007108:Immune Tolerance; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D007893:Leishmania donovani; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000473:pathology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology*; D018417:Th1 Cells / Q000276:immunology / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology / Q000473:pathology
D016207:Cytokines; D007376:Interleukin-2; D007371:Interferon-gamma