A Platelet-Derived Immunoregulatory Serum Factor with T Cell Affinity,
SLOAN-KETTERING INST FOR CANCER RESEARCH NEW YORK
Pagination or Media Count:
A factor in mouse and human serum which enhances immune responses to Sheep erythrocytesSRBC and Total Net PositiveTNP-Ficoll in mice has been described. This factor completely reverses immunosuppression induced by syngeneic lymphoma RCS or allogeneic lymph node cells. T lymphocytes bind this factor, since the activity can be removed from serum by absorption with T cell containing spleen cells or cloned cytotoxic T lymphocytes. Furthermore, the factor is active only in the presence of mature T cells. Platelet alpha-granules seem to be the source of this serum factor because 1 the activity is lacking in plasma, in serum prepared in the absence of platelets, and in serum prepared from a patient lacking platelet alpha-granules and 2 isolated mouse or human platelets release an immunostimulatory factor with very similar properties upon incubation with thrombin.
- Medicine and Medical Research