Biomaterial Database

Receptors for IgM on human lymphocytes. I. Detection of receptors on freshly drawn lymphocytes and at physiological temperature. 1979

M W Fanger, and P M Lydyard

Receptors for the Fc portion of IgM (RFcmu) have previously been found to be primarily associated with the T lymphocyte subpopulation in humans, and their detection has frequently required overnight incubation of the cells before assay. In the present study, using highly sensitized indicator cells (EAmu), lymphocytes with receptor for IgM (EAmu-RFC) were detected immediately after isolation from human peripheral blood. Identification of EAmu-RFC on freshly isolated lymphocytes was greatly facilitated by assay at room temperature (RT) or 37 degrees C, implying that analogous interactions between IgM-antigen complexes and lymphocytes with receptor for IgM normally occur in vivo. These results seem to indicate that some RFcmu on lymphocytes may be occupied by IgM and/or IgM-antigen complexes in vivo and that immediately after isolation many RFcmu are still occupied and unavailable for interaction with EAmu. It is suggested that the successful competition of IgM-antigen complexes for RFcmu on T lymphocytes is the signal for and/or mechanism of expression of help by the lymphocyte. The sensitivity of the assay for EAmu-RFC also permitted the identification of a small subpopulation of RFcmu+ lymphocytes in the non-T cell fraction of the peripheral blood of some individuals.

UI	MeSH Term	Description	Entries
D007075	Immunoglobulin M	A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally was called a macroglobulin.	Gamma Globulin, 19S,IgM,IgM Antibody,IgM1,IgM2,19S Gamma Globulin,Antibody, IgM
D007141	Immunoglobulin Fc Fragments	Crystallizable fragments composed of the carboxy-terminal halves of both IMMUNOGLOBULIN HEAVY CHAINS linked to each other by disulfide bonds. Fc fragments contain the carboxy-terminal parts of the heavy chain constant regions that are responsible for the effector functions of an immunoglobulin (COMPLEMENT fixation, binding to the cell membrane via FC RECEPTORS, and placental transport). This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.	Fc Fragment,Fc Fragments,Fc Immunoglobulin,Fc Immunoglobulins,Ig Fc Fragments,Immunoglobulin Fc Fragment,Immunoglobulins, Fc,Immunoglobulins, Fc Fragment,Fc Fragment Immunoglobulins,Fc Fragment, Immunoglobulin,Fc Fragments, Ig,Fc Fragments, Immunoglobulin,Fragment Immunoglobulins, Fc,Fragment, Fc,Fragments, Ig Fc,Immunoglobulin, Fc
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000915	Antibody Affinity	A measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.	Affinity, Antibody,Antibody Avidity,Avidity, Antibody,Affinities, Antibody,Antibody Affinities,Antibody Avidities,Avidities, Antibody
D000936	Antigen-Antibody Complex	The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.	Immune Complex,Antigen-Antibody Complexes,Immune Complexes,Antigen Antibody Complex,Antigen Antibody Complexes,Complex, Antigen-Antibody,Complex, Immune,Complexes, Antigen-Antibody,Complexes, Immune
D001666	Binding Sites, Antibody	Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.	Antibody Binding Sites,Paratopes,Antibody Binding Site,Binding Site, Antibody,Paratope
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures