POSTNATAL-DEVELOPMENT OF LYMPHOCYTE SUBPOPULATIONS IN THE INTESTINAL LYMPH-NODES IN GOATS

The incidence and location of CD2(+), CD4(+), CD8(+) and gamma/delta T lymphocytes and IgM(+) B lymphocytes were studied in the intestinal l ymph nodes in 1-week, I-month, 3-month and 7-month-old goats, using mo noclonal antibodies and immunohistochemical methods. The cortical area of the intestinal lymph nodes in I-week-old animals contains only pri mary follicles occupied by IgM(+) B lymphocytes and some CD2(+)CD4(+) T lymphocytes. In goats older than 1 month, secondary follicles, that increased in number and size with age, were observed; the light zone o f the germinal centre was occupied by IgM(+) lymphocytes and some CD2 and CD4(+) T lymphocytes. In the other compartments of the lymph node s, B lymphocytes were scarce, their number increasing with age in the medulla and diminishing in the paracortex. The numerous CD2(+) T lymph ocytes in the interfollicular area increased in number in the paracort ical area of the 7-month-old goats, simultaneously with an increase in the MHC II+ dendritic cells and the CD4/CD8 ratio, which was greater than 1. The gamma/delta T lymphocytes represented a minor subpopulatio n scattered through the lymph nodes.