Antibody

About: Antibody is a research topic. Over the lifetime, 113941 publications have been published within this topic receiving 4130181 citations. The topic is also known as: Ab & antibodies.

Differential responses of human tumor cell lines to anti-p185HER2 monoclonal antibodies.

Abstract: The HER2 protooncogene encodes a receptor tyrosine kinase, p185HER2. The overexpression of p185HER2 has been associated with a worsened prognosis in certain human cancers. In the present work we have screened a variety of different tumor cell lines for p185HER2 expression using both enzyme-linked immunosorbent and fluorescence-activated cell sorting assays employing murine monoclonal antibodies directed against the extracellular domain of the receptor. Increased levels of p185HER2 were found in breast (5/9), ovarian (1/6), stomach (2/3) and colorectal (5/16) carcinomas, whereas all kidney and submaxillary adenocarcinoma cell lines tested were negative. Some monoclonal antibodies directed against the extracellular domain of p185HER2 inhibited growth in monolayer culture of breast and ovarian tumor cell lines overexpressing p185HER2, but had no effect on the growth of colon or gastric adenocarcinomas expressing increased levels of this receptor. The most potent growth-inhibitory anti-p185HER2 monoclonal antibody in monolayer culture, designated mumAb 4D5 (a murine IgG1κ antibody), was also tested in soft-agar growth assays for activity against p185HER2-overexpressing tumor cell lines of each type, with similar results. In order to increase the spectrum of tumor types potentially susceptible to monoclonal antibody-mediated anti-p185HER2 therapies, to decrease potential immunogenicity issues with the use of murine monoclonal antibodies for human therapy, and to provide the potential for antibody-mediated cytotoxic activity, a mouse/human chimeric 4D5 (chmAb 4D5) and a “humanized” 4D5 (rhu)mAb 4D5 HER2 antibody were constructed. Both engineered antibodies, in combination with human peripheral blood mononuclear cells, elicited antibody-dependent cytotoxic responses in accordance with the level of p185HER2 expression. Since this cytotoxic activity is independent of sensitivity to mumAb 4D5, the engineered monoclonal antibodies expand the potential target population for antibody-mediated therapy of human cancers characterized by the overexpression of p185HER2.

Regulatory effect of antibody on the immune response.

Abstract: Publisher Summary This chapter deals with the regulatory effect of antibody on antibody formation. It is possible to analyze those factors that influence the process of antibody synthesis. Certainly antibody, the end product of the process, is among the most potent and specific of inhibitors of antibody synthesis. That this inhibition results from the interaction of antibody with antigen neutralizing the immunogenicity of the latter seems likely, and the evidence for this is critically presented. The potential use of this mechanism is suggested by its effectiveness in the enhancement of tissue grafts, its use in the therapeutic prevention of anti-D antibody responses in mothers of Rh-incompatible fetuses, and its possible role in the induction of some types of immunological tolerance. The immune response represents a predictable series of events, characterized by the sequential appearance of several classes of γ-globulin antibody molecules and the expression of various cell-mediated immune reactions. One mechanism is described for regulating the concentration of immunoglobulin (IgG) in the circulation. The mechanism operates by increasing the catabolic rate of IgG when the serum concentration is abnormally increased as, for example, in multiple myeloma. Two mechanisms are described both of which regulate the immune response. These are alteration of antigenic stimulation and suppression of the immune response by passive transfer of specific antibodies prior to or shortly after administration of antigen.

A role for carbohydrates in immune evasion in AIDS

Abstract: Rhesus monkeys were infected with mutant forms of simian immunodeficiency virus lacking dual combinations of the 4th, 5th and 6th sites for N-linked glycosylation in the external envelope glycoprotein of the virus. When compared with sera from monkeys infected with the parental virus, sera from monkeys infected with the mutant viruses exhibited markedly increased antibody binding to specific peptides from this region and markedly increased neutralizing activity. These results demonstrate a role for N-linked glycosylation in limiting the neutralizing antibody response to SIV and in shielding the virus from immune recognition.

Systemic lupus erythematosus: an autoimmune disease of B cell hyperactivity.

Abstract: B cells can regulate many aspects of immune reactivity, as well as differentiate into antibody-producing cells. In SLE, a systemic autoimmune disease, recent research suggests enhanced B cell function is the defining pathogenic event.