Modification of the chemiluminescent response of rat thymocytes to concanavalin A by the acute non-specific inflammatory process.

Using the technique of concanavalin A-induced chemiluminescence (CL) as a measure of lymphocyte reactivity it has been demonstrated that the acute non-specific inflammatory process initiated by a non-diffusible, non-antigenic, endotoxin free irritant, was able to enhance the CL response of rat thymocytes. Maximum enhancement was observed 48 h after initiation of the inflammatory reaction. Serum derived from animals undergoing an acute inflammatory reaction as used above was fractionated using the technique of ultrafiltration to yield a fraction of molecular weight range 500-2000 daltons. When this fraction was cultured in vitro for 22 h with normal thymocytes, the CL response to concanavalin A was greatly enhanced when compared to thymocytes cultured in the presence of an equivalent fraction of normal serum. These findings demonstrate that during an acute non-immunological inflammatory reaction the function of the hosts thymocytes is enhanced. Furthermore, a low molecular weight factor (500-2000), with thymocyte stimulating activity, may be recovered from the serum of such animals very quickly (within 2 h) after initiation of the acute inflammation.