A quantitative analysis of lymphokine release from activated T cells. Evidence for a novel form of T-T collaboration in vitro.

Abstract

We previously developed a simple mathematical model describing Ag-triggered lymphokine release from activated T cells. Previous test of this model revealed qualitative differences in the antigenic requirement for lymphokine release between activated T cell populations with the same apparent specificity when activated under different conditions. We now have found a case where class I MHC-reactive T cells (class I T cells) can modulate the nature of Ag-triggered lymphokine release from class II MHC-reactive T cells (class II T cells). Two significant requirements for this modulation event are: 1) Linked recognition/presentation of class I and class II Ag; that is, class I and class II MHC alloantigens must be presented on the same APC, and 2) active participation of the APC in this process; metabolic inactivation of the APC abrogates the class I T cell modulation of the class II activated T cell. These results suggest a novel form of T-T collaboration that involves the active participation of the APC, and provides evidence that T cells of one MHC specificity (class I) can influence the function of T cells of another MHC specificity (class II).