Immunobiological studies on experimental visceral leishmaniasis. IV. Kinetics of evolution of disease-promoting versus host-protective cells of monocyte-macrophage lineage and their characterization.
The evolution of cells of the monocyte-macrophage lineage (MML cells) in the spleen of Leishmania donovani (LD) infected BALB/c mice was studied. Spleen cells were fractionated on a discontinuous percoll gradient and adherent cells (AC) were purified from fractionated spleen cells by adherence steps that appeared at the interfaces of 25-35%, 35-40%, 40-45% and 45-50% percoll gradients. The AC were characterized as MML cells on the basis of positive staining for non-specific esterase. Adherent cells that appeared at the interfaces of 25-35% and 40-45% were defined as A and C, respectively, and both of them showed extreme variation in a progressive infection. It was observed that A supported parasite replication whereas C remained refractory when infected with LD in vitro. Furthermore, when A cells and C cells were used as antigen-presenting cells to stimulate mixed population of IFN-gamma producing and IL-4 producing T-cells, it was observed that IL-4 and IFN-gamma were the predominating cytokine in the T-cell supernatant, respectively. Both A and C were found to be increased hand-in-hand up to 5 months of infection and from then on A decreased and C increased in their numerical strength (A-C reciprocity). The evolution of A-C reciprocity coincided with the gradual reduction in the parasitaemia in the spleen suggesting that this may contribute to the acquisition of anti-leishmania immunity.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D002469:Cell Separation; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000502:physiology; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000276:immunology*; D013154:Spleen / Q000166:cytology
D016861:Cyclooxygenase Inhibitors; D007375:Interleukin-1; D007213:Indomethacin