title: Suppressor macromolecules.
abstract: An amazing number of nonspecific and specific suppressor molecules that dampen immune reactivity have been described in the past two decades. This review, however, focuses on both nonspecific and specific endogenous suppressor macromolecules and attempts to group them into biochemically and functionally similar compartments. For the nonspecific inhibitors these groupings include normal serum protein suppressors; suppressor macromolecules found in altered states such as infectious disease, cancer, pregnancy, and malnutrition; and immunosuppressants derived from various tissues including both nonlymphoid and lymphoid tissue. In addition, suppressor macromolecules that display some degree of specificity are also included. The groupings for these proteins include those that are restricted in their response to a certain class of immunoglobulin antibody response, those that are restricted with respect to their actions by the major histocompatibility complex and those that are restricted with respect to antigen. Finally, this review attempts to rationalize the potential advantages and raison d'etre for conserving the plethora of both nonspecific and specific factors and speculates on their potential value in immune responses.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007136:Immunoglobulins / Q000276:immunology; D007166:Immunosuppressive Agents / Q000276:immunology*; D008222:Lymphokines / Q000276:immunology; D008285:Major Histocompatibility Complex; D008297:Male; D009369:Neoplasms / Q000276:immunology; D011247:Pregnancy; D011506:Proteins / Q000276:immunology*; D000509:alpha-Fetoproteins / Q000276:immunology
chemical_list: D001798:Blood Proteins; D000939:Epitopes; D007136:Immunoglobulins; D007166:Immunosuppressive Agents; D008222:Lymphokines; D011506:Proteins; D000509:alpha-Fetoproteins