Thrombocyte migration and the release of thrombocyte inhibitory factor (ThrIF) by T and B cells in the chicken

The elaboration of various inhibitory factors by sensitized lymphocytes has been reported for both mammals and birds. Until recently, the ability of the B cell to elaborate these had been questioned by a number of investigators. We have demonstrated the release of a lymphocyte inhibitory factor from the avian thymus and bursal lymphocyte. The avian thrombocyte is active in haemostasis as well as being a phagocytic cell. We have demonstrated that the ability of the thrombocyte to migrate, significantly exceeded that of thymic lymphocytes. Sensitized T and B cells, as well as activated supernatants from these cells, were capable of inhibiting thrombocyte migration. Treatment of sensitized B cells with anti-T-cell serum plus complement failed to eliminate this cell's ability to block thrombocyte migration. These data attribute the capability of elaborating a thrombocyte migration inhibitory factor to both the avian thymic and bursal lymphocyte, and attribute a degree of maturity to these cells not previously demonstrated.