The distribution of lymphocyte subsets in normal ovine skin

The distribution of lymphocyte subsets in the skin of clinically normal sheep was studied using monoclonal antibodies to OvCD5, OvCD4, OvCD8, WC1, and CD45RA. Four different anatomical sites were examined in each of 38 sheep. Four different age groups ranging from 7 to 10-day-old lambs to 12 to 14-month-old adults were represented. The majority of lymphocytes in all age groups and at all sites were angiocentrically located within the superficial dermis. Total lymphocyte numbers at each site increased with age. The predominant cell type identified at all sites was WC1+ and the proportion of lymphocytes of this phenotype was significantly higher at wooled sites. Only occasional CD45RA± cells were present in any section.