POSTNATAL DEVELOPMENT OF LYMPHOCYTE SUBPOPULATIONS IN THE PEYER'S PATCH GOAT

Abstract

The incidence and location of CD2⁺, CD4⁺, CD8⁺ and y/d T lymphocytes, IgM⁺ B lymphocytes and MHC II⁺ cells were studied in yeyunal and ileocaecal Peyer's patches in goat of one week, one month, three months and seven months, using monoclonal antibodies and immunohistochemical methods. The germinal centres of the follicles of the Peyer's patches are occupied by numerous IgM⁺ B lymphocytes and some CD2⁺CD4⁺ T lymphocytes which increase with age, particularly in the ileocaecal Peyer's patches. In one week old goats IgM⁺B lymphocytes are scarce in outer corona, dome and interfollicular area in ileocaecal Peyer's patches and are absent in yeyunal Peyer's patches. In one month old goats the IgM⁺ B lymphocytes increase in these loca- tions in both Peyer's patches, and their number doesn't change much with age. In all the animals, the interfo-llicular area is occupied fundamentally by CD2⁺ T lymphocytes with a CD4/CD8 ratio greater than 1. In the dome the CD2⁺ T lymphocytes are more numerous in one week-old goats than in goats older than one month, where the CD4/CD8 ratio is greater than 1, increasing with age. The y/d T lymphocytes are scarce in all compartments in both Peyer's patches.