Specific blastogenesis and lymphokine production in DNCB-sensitive human leucocyte cultures stimulated with soluble and particulate DNP-containing antigens.

A soluble hapten (dinitrobenzene sulphonic acid (DNBSO3)) and particulate antigens consisting of DNCB, DNFB or DNBSO3 complexed with erythrocytes, all induce a specific blastogenic response and lymphokine production in leucocyte cultures from human subjects topically sensitized to dinitrochlorobenzene (DNCB). While low concentrations (50-100 mug/ml) of DNBSO3 could be left in human leucocyte cultures the entire 4 or 5 days of culture and result in reasonable levels of blastogenesis, it was found that consistently higher degrees of blast transformation resulted when DNCB-sensitive leucocytes were exposed to high concentrations of DNBSO3 (500 mug/ml) for a short period (2 hr). Cell-free supernatants from DNCB-sensitive leucocyte cultures harvested after 48 hr induced blastogenesis and DNA synthesis in secondary target leucocyte cultures from subjects not sensitized to DNCB. Such a blastogenic factor or lymphokine appeared to stimulate even in the absence of any residual antigen, since DNCB complexed to erythrocytes was removed by simple filtration through a 0-45 mum Millipore filter. In contrast to DNCB complexes, the antigenic activity of DNBSO3 complexed with erythrocytes was not removed by such filtration. Thus, several DNP-containing haptens (DNCB, DNFB, DNBSO3) induce specific lymphocyte transformation and lymphokine production when exposed in several different manners to leucocytes from humans sensitized to DNCB. The ability to use either a particulate or soluble stimulant in vitro offers a versatile system for studying cell-mediated immunity in humans with a broad range of potential applicability in both investigate and clinical medicine.