Postnatal evolution of lymphocyte subpopulations in peripheral blood and lymphoid organs in the goat

Monoclonal antibodies (mAbs) against bovine leukocyte antigens specific for T cells (CD2, CD4, CD8 and gamma delta receptor) and B cells (surface IgM) were used in samples from one week and one-, three- and seven-month-old goats to study the evolution of lymphocyte subsets by flow cytometry in peripheral blood and the lymphoid organs: thymus, jejunal (JPP) and ileal (IPP) Peyer's patches, spleen and mesenteric lymph nodes. An increase in the values of alpha/beta receptor T cells with age was recorded whereas the gamma/delta receptor T cells fell in number. In peripheral blood and in all tissues, except IPP the values for B cells (sIgM(+)) were low. The CD4(+) and CD8(+) cells predominated in JPP while B cells were the most important subpopulation in IPP. In the spleen, as in JPP, the CD4/CD8 ratio was less than one and the gamma delta T cells values were high. In mesenteric lymph nodes, CD8(+) and B(sIgM) cells predominated in the youngest animals.