Abstract

The immune system of sheep, cattle and other ruminants contains unusually large numbers of gamma-delta () T lymphocytes. In lambs and calves, these cells may comprise more than 50% of the T cells circulating in blood while in rodents and primates, they typically account for less than 5% of blood-borne T cells. The T cells localise within mucosal surfaces of all species, particularly in the gastrointestinal tract. Compared to their rodent and human counterparts, ruminant T cells have a greatly expanded repertoire of antigen receptors (Hein & Dudler, 1993, 1997). They also express unique accessory molecules in their cell membrane which may reflect a differential capacity of the ruminant T cells to contribute to immune defence (Hein & Mackay, 1991).

NM, Schreurs, A Pernthaner, WR Hein, and TN Barry

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 288-290, 2010