Identification of positive cells to interleukin-4 in bovine haemal nodes

The bovine haemal nodes are lymphatic organs located in the haemal circulat ion. Their parenchyma is represented by plasma cells, macrophages and B and T lymphocytes. The T helper type 2 (Th2) CD4 lymphocyte can be found withi n the T lymphocytes. The activated Th2 CD4 lymphocyte produces interleukin- 4 (IL-4), a peptidic hormone involved in the acute-phase immune response. T his interleukin can promote either B-lymphocyte differentiation and T-lymph ocyte proliferation or it can promote the type of immunoglobulin that can b e liberated. Our results have shown, by immunostaining with anti-IL-4, not only the presence and localization of these lymphocytes in bovine haemal no des but also the participation of polymorphonuclear cells (neutrophils) in the storage of IL-4. These results give value to the humoral and cellular i mmunological importance of haemal nodes in bovines and they can serve as a contribution to determine the crossreactivity of bovine IL-4 with the human anti-serum used in this work.