Blastogenesis of Autologous, Allogeneic, and Syngeneic (Identical Twins) Lymphocytes in Response to Lymphokines Generated in Dinitrochlorobenzene-Sensitive Human Leukocyte Cultures

Abstract

Abstract Dinitrochlorobenzene (DNCB) coupled to peripheral blood erythrocytes or leukocytes forms a particulate complex (DNCB-antigen) capable of inducing lymphocyte transformation when added to peripheral blood leukocyte cultures prepared from human subjects specifically sensitized to DNCB. Biologically active soluble factor(s) are released into the cell-free supernatant of sensitive leukocyte cultures when stimulated by DNCB-antigen, but are not released in unstimulated control cultures. The active soluble supernatant factor(s) induced blastogenesis and DNA synthesis when added to secondary target leukocyte cultures prepared from subjects not sensitized to DNCB. Under the conditions employed in these experiments, maximal DNA synthesis was induced in secondary target leukocyte cultures when supernatants of primary sensitive cultures were collected 24 to 72 hr after stimulation and decreased rapidly thereafter. Increasing amounts of the active soluble factor(s) induced almost proportional increases in DNA synthesis in target leukocyte cultures, illustrating the quantitative nature of the blastogenic assay. Allogeneic and syngeneic leukocyte cultures from subjects not sensitized to DNCB showed levels of DNA synthesis comparable to autologous sensitive leukocyte cultures in response to the soluble factor(s). Thus, the soluble factor(s) which are specifically released after the induction of allergic contact dermatitis to DNCB appear to be lymphokine(s) which express blastogenic activity independent of the genetic origin or antigenic sensitivity of the target leukocyte population.