Chemiluminescence and lymphocyte proliferation: parallelism in collaboration between subpopulations of thymus cells...

Rat thymocytes respond to exposure to phytomitogens by oxidant generation as detected by chemiluminescence in presence of luminol. Maximal chemiluminescent response to a wide variety of plant lectins was obtained only after the cells had been incubated for 18 hours at 37 degrees C but not at 4 degrees C. This temperature dependence and the necessity for intact protein-and RNA-synthetic machinery during the incubation period indicate the occurrence of differentiation of thymocytes as they develop the capacity for chemiluminescent response. Furthermore, adherent-phagocytic cells play an essential collaborative role during this differentiation. A remarkable parallelism was shown to exist in the capacity of a cell subset to respond to concanavalin A by DNA synthesis and the ability of the same subset to respond by chemiluminescence. The latest-sedimenting small lymphocytes after velocity sedimentation of thymus cells develop the capacity for DNA-synthetic as well as chemiluminescent responses to concanavalin A only if allowed to collaborate with a population of early-sedimenting adherent-phagocytic cells.