Investigation of bovine gut associated lymphoid tissue (GALT) using monoclonal antibodies against bovine lymphocytes.

Gut associated lymphoid tissue of the small and large intestine of calves and cows has been compared morphologically and quantitatively using monoclonal antibodies to bovine lymphocytes. B cells were significantly decreased in the ileum of the cow compared to the calf. Significantly increased numbers of T cells were present in cell suspensions of all lymphoid areas of the cow compared to the calf. T lymphocyte subsets were quantified into cryostat sections of lymphoid tissues expressing BoT4, and BoT8 antigens demonstrated increased numbers in follicular and dome areas of the discrete Peyer's patches of the small and large intestine of the cow. BoT4+, BoT8+, and the non-BoT4/BoT8+ T cell subsets were increased in the mucosa of the cow as compared to the calf. Similarities in structure and lymphocyte composition of the discrete Peyer's patches of the small intestine, cecum and colon and isolated single follicles in the large intestine suggest similar functional properties.