Antigenicity

Abstract: Immunogenicity depends on two key factors: antigenicity and adjuvanticity. The presence of exogenous or mutated antigens explains why infected cells and malignant cells can initiate an adaptive immune response provided that the cells also emit adjuvant signals as a consequence of cellular stress and death. Several infectious pathogens have devised strategies to control cell death and limit the emission of danger signals from dying cells, thereby avoiding immune recognition. Similarly, cancer cells often escape immunosurveillance owing to defects in the molecular machinery that underlies the release of endogenous adjuvants. Here, we review current knowledge on the mechanisms that underlie the activation of immune responses against dying cells and their pathophysiological relevance.

Abstract: Indirect immunofluorescence of certain human sera demonstrated an antigen(s) in the cytoplasm of 1--5% of the cells of a T-cell line, MT-1, from a patient with adult T-cell leukemia (ATL), which is endemic in southwestern Japan. The antigen was not detected in other human lymphoid cell lines, including six T-cell lines, seven B-cell lines, and four non-T non-B cell lines. The antigen did not show cross antigenicity with that of herpesviruses, including Epstein--Barr virus, herpes simplex virus, cytomegalovirus, varicella-zoster virus, herpesvirus saimiri, and Marek disease virus. The proportion of antigen-bearing cells was increased by a factor of approximately 5 on culture in the presence of 5-iodo-2'-deoxyuridine. Antibodies against the antigen in MT-1 cells were found in all 44 patients with ATL examined and in 32 of 40 patients with malignant T-cell lymphomas (most of them had diseases similar to ATL except that leukemic cells were not found in the peripheral blood). The antibodies were also detected in 26% of the healthy adults examined from ATL-endemic areas but in only a few of those examined from ATL-non-endemic areas. On electron microscopy, extracellular type C virus particles were detected in pelleted MT-1 cells cultured in the presence of 5-iodo-2'-deoxyuridine.

Abstract: General features of the immune responses antigens and antigenicity destruction of foreign material - the myeloid system mactophages and antigen processing the major histocompatibility complex the tissues of the immune system lymphocytes the helper T cell response lymphokines and cytokines antibodies the genetic basis of antigen recognition the cellular basis of antibody formation the complement system effector T cell function tissue transplantation resistance to tumours tolerance and regulation of the immune system serology - the detection and measurement of antibodies immunity at body surfaces immunity in the fetus and newborn general principles of vaccination and vaccines resistance to bacteria and related organisms resistance to viruses immunity to parasites inflammation type 1 hypersensitivity erythrocyte antigens adn type 2 hypersensitivity type 3 hypersensitivity cell-mediated (type 4) hypersensitivity autoimmunity - general principles organ-specific autoimmune diseases the systemic immunological diseases primary immune deficiencies secondary immunological defects drugs that affect the immune system the phylogeny of the immune system.