ARE DIFFERENTIATED HUMAN T-HELPER CELLS REVERSIBLE

Cytokines and cytokine antagonists have important roles in controlling the type of immune response generated. These mediators have the most profound effects if used at the initiation of an immune response. For example, IL-4 and IL-12 are important determinants in the generation o f Th1 and Th2 cells, respectively, in both murine and human systems. O ne critical question that relates to human pathogenesis is whether Th1 - and Th2-type cells can be altered after disease is initiated. Data w ill be presented showing how cytokines can change the types of cytokin es produced from established Th1 and Th2 cells. Moreover, intracellula r staining of cytokines was done to more accurately define whether cyt okine production was altered on a single cell basis. These studies may have implications for immune manipulation for established allergic or autoimmune diseases.