CD56 and CD3 expression in the liver and spleen of dogs with visceral leishmaniasis

NKT cells are a subpopulation of lymphocytes with NK cell (CD56+) and T lymphocytes (CD3+) characteristics.These cells may to exterminate the infected cells and play an essential role in innate immunity.The objective of the present study was, through the immune histo-chemical technique, to analyze the livers and spleens of dogs with VL, considering the presence of parasites, CD56 and CD3 imuno detection.A total of 71 naturally infected dogs (infected group) from an endemic area for VL was used.A control group (C=10) was obtained from a not endemic area for VL.In the parasite load analysis, both liver and spleen showed no significant difference in the infected dogs.The immune detection of CD56 was low and not differ between the infected and control groups (P=0.7787) in liver.However, in spleen there were significant differences (P=0.0385) between infected (median=3.40)and control groups (median=13.70).CD3 showed significant differences in the liver (P=0.0229) of the infected (median=42.40) and control (median=7.90).In spleen these difference occurred between (P=0.0081)infected (median=51.0) and control groups too (median=381.0).Thus, we suggest that in the spleen and liver of infected dogs, the expression of CD56 and CD3 cells did not play a cytotoxic effect on parasitized macrophages in infected dogs.The proportion of CD56+ and CD3+ phenotypes was low in the infected group, suggesting that this cytotoxic way seems not to be efficiently activated in dogs with VL, regardless of the parasite load of each organ.