Rapid changes occur in the percentage of circulating bovine WC1+γδ Th1 cells

• Published in: Research in veterinary science Vol. 69; no. 2; pp. 175 - 180
• Main Authors: BALDWIN, C.L, SATHIYASEELAN, T, ROCCHI, M, McKEEVER, D
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2000
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1053/rvsc.2000.0410

γδ T cells found in the peripheral blood of cattle include a major subpopulation distinguished by expression of WC1. These cells are distinct from the WC1–γδ T cell population based on T cell receptor gene usage. We documented that a group of 6-month-old calves allowed free-range grazing and access to their mothers had a significantly greater proportion of total γδ T cells in their blood, attributable to the WC1+γδ T cell subpopulation, compared to age and breed-matched calves held in conventional housing. When the animals with the greater proportion of γδ T cells were transferred to conventional housing there was a decrease in the WC1+population so that by 3 weeks after transfer there was no longer a significant difference between the two groups. To investigate the biological activities of WC1+γδ T cells, the cells were purified by flow cytometric sorting. In vitro, they responded to stimulation by irradiated monocytes in autologous mixed leukocyte reaction (AMLR) cultures but not to direct stimulation through the T cell receptor (T c R) by anti-δ monoclonal antibody. After stimulation in the AMLR, WC1+γδ T cells had a Th1 cytokine profile characterised by production of IFN -γ and lack ofIL -4. Thus we propose that higher levels of the WC1+γδ T cells may provide calves with a mechanism to produce Th1 cytokines and that the level of these cells may be modulated according to environment or stress since both groups of calves were apparently disease-free.