The immune system and lymphoma. (A commentary on the role of the immune system in experimental lymphomagenesis)

Normal immune responsiveness is compared with four main types of experimental lymphomagenesis. In these types of lymphoma, the proximal cause of lymphomagenesis can be identified as a specific class of the immunoregulatory defect. The adaptive differentiation of normal immunocytes to immunocompetence permits the specific activation by antigenic determinants through the requirement for cognate recognition of such epitopes in the presence of an actively maintained self-tolerant state. Defective control of immune responsiveness in lymphomagenesis permits lymphocyte activation by stimuli resulting from the acquisition of alterations or defects in the expression of normally invariant molecules present during adaptive differentiation. Target antigens include class I and II MHC, env glycoproteins, and framework determinants of T cell receptor or immunoglobulin idiotype. Features common to both normal immune responsiveness and to lymphomagenesis are immunocompetence of the cognate recognition process and specificity of the target immunocyte for the permitted immunogenic or lymphomagenic stimulus.