PERFORIN-LIKE IMMUNOREACTIVITY IN FELINE GLOBULE LEUKOCYTES AND THEIRDISTRIBUTION

Distributional and immunohistochemical characteristics of the feline g lobule leukocyte (GL) were investigated by light microscopy. The GL, w hich contained eosinophilic large granules in the cytoplasm, was frequ ently found in the epithelia of the intestine and gall bladder, and le ss frequently found in those of the gastric pit, intrahepatic bile duc t, and interlobular secretory duct of the pancreas. No GL was seen in the respiratory and urogenital organs. The GLs composed a homogeneous cell population including no mast cells according to the following his tochemical stainings; phosphotungstic acid hematoxylin, alcian blue an d peroxidase. The feline GL showed perforin-like immunoreactivity to a nti-human perforin monoclonal antibody, but did not show histamine-imm unoreactivity to anti-histamine polyclonal antibody. The results sugge st that the feline GL is a lineage of large granular lymphocytes. The epitheliotropism and the characteristics as granular lymphocytes of th e feline GLs were similar to those of the intestinal gamma delta T cel ls of the mouse.