Enhancement of phytohemagglutinin and concanavalin A responses of splenic lymphocytes by adherent cell removal.

Removal of glass wool-adherent cells resulted in an enhancing effect on DNA synthesis as measured by increased [3H]-thymidine uptake by normal swine spleen cells stimulated with phytohemagglutinin or concanavalin A (Con A). Depletion of nylon-adherent cells caused decreased DNA synthesis in response to Con A, except at high doses of Con A, whereas similar cultures stimulated with phytohemagglutinin showed enhanced DNA synthesis throughout the dose range employed. Titration experiments revealed that enhancing effects of adherent cell removal are most pronounced at higher cell and mitogen concentrations. Glass wool was more efficient than nylon in the enhancement of mitogen-induced DNA synthesis.