Immunohistology of the splenic compartments of the one humped camel (Camelus dromedarius)

The cellular composition of the different splenic compartments is well char acterized in several species, but the spleen of the camel has not been stud ied due to the lack of specific antibodies detecting its leukocyte subsets. Therefore, 5 mu m frozen sections from 15 camel spleens (0.5-15 years) wer e studied for acid and alkaline phosphatases and for cross-reaction with an tibodies specific for bovine (n=181), swine (n=14) and human (n=6) leukocyt e determinants. Fifteen antibodies cross-reacted with camel spleen cells. T hese included 13 anti-bovine, two anti-human, but no anti-swine antibodies. The lymph follicles mainly consisted of B cells. The germinal centers show ed a strong alkaline phosphatase activity. The periarterial lymphatic sheat h harbored T lymphocytes. The marginal zone contained gamma delta T cells, CD45RO+, MHC class II DR+, CD44+, IL-A24+ cells and few macrophages. The re d pulp contained B, T, MHC class II DR+, IL-A24+ and gamma delta T cells an d few macrophages. The periarterial macrophage sheaths contained many more macrophages than the marginal zone, so they may play a central role in the phagocytosis of the blood born particles. The alkaline phosphatase probably labeled activated B cells, but in contrast to other species no positive ce lls were found in the marginal zone. In general, lymphocyte compartmentaliz ation in the camel spleen is similar to that in other species except for lo wer numbers of macrophages and the absence of alkaline phosphatase positive cells in the marginal zone. No age related differences were observed in th e splenic compartments. (C) 2000 Elsevier Science B.V. All rights reserved.