一Class II MHC Ag Memory B cel Antibe B cell Class ll MCH Ag TCR T Cell Ag B Cell The relative ability of each individual to respond to the antigenic universe is inherited toalarge extet Lymphocytes neither reprode in uncontroled fashion nor continuously produce increasing quantities of antibodies or lymphokines.A decline in functional expression follows primary and secondary immune responses. Hence specific immune responses must be down-regulated in some fashion.Several mechanisms operate to modulate immunological expr ssion.Positive regulators include antigens and cytokir (IL-1,IL-2.BCGF,and BCDF)from macrophages and helper/inducer T Cells. The relative ability of each individual to respond to the antigenic universe is inherited to a large extent. Lymphocytes neither reproduce in uncontrolled fashion nor continuously produce increasing quantities of antibodies or lymphokines. A decline in functional expression follows primary and secondary immune responses. Hence specific immune responses must be down-regulated in some fashion. Several mechanisms operate to modulate immunological expression. Positive regulators include antigens and cytokines (IL-1, IL-2, BCGF, and BCDF) from macrophages and helper/inducer T Cells