Flow cytometric characterization of the lymphocyte composition in a variety of mucosal tissues in healthy rhesus macaques

Background  Rhesus monkeys play a central role in model studies on human infectious diseases, and often mucosal organs are affected by these pathogens, e.g. HIV. However, a comparative investigation into lymphocyte composition from different mucosal tissues is still missing. Methods  Lymphocyte composition of duodenum, jejunum, ileum, colon, vagina, cervix, uterus and bronchoalveolar lavage from healthy rhesus monkeys was characterized in detail by flow cytometry. Moreover, we compared the lymphocyte proportions from intestinal biopsies with resections. Results  All mucosal tissues exhibited higher values of CD8+, CD4+ CCR5+ and CD45RA− memory T cells than blood, but similar levels of total T cells. Especially within the four gut sites, the lymphocyte composition varied significantly. The relative proportions of lymphocyte subsets from duodenal and colonic biopsies compared to resections differed. Conclusion  The lymphocyte composition highly varies between different mucosal sites, and data obtained from biopsy and necropsy samples were mostly not comparable.