title: Immunoglobulin VH determinants defined by monoclonal antibodies.
abstract: Hybridoma clones secreting antibodies against common VH determinants were readily produced by fusion of cells from mice immunized with isolated V mu fragments of human immunoglobulins (Ig), but not with intact Ig molecules or isolated heavy chains. Four monoclonal antibodies to the V mu fragments of different IgM paraproteins were selected for analysis: MH-44 (mu kappa), GB-24 (mu kappa), NF-11 (gamma 1 kappa), and SA-44 (gamma 1 kappa). Each antibody reacted with the homologous V mu fragment, homologous mu chain, and normal gamma chains, but not with the intact IgM molecules, intact IgG, or isolated light chains, as determined by radioimmunoassay. The VH reaction spectra with a panel of myeloma heavy chains showed overlapping but distinctive patterns for the four antibodies. Each of the four monoclonal anti-VH antibodies appeared to react with a different "hidden" VH determinant that is not exposed on undenatured, intact Ig molecules and differs from conventional VH subgroup determinants. In immunofluorescence studies, the monoclonal anti-VH antibodies did not bind to surface Ig on viable B lymphocytes, but visibly stained subpopulations of fixed B lymphocytes, pre-B cells, and normal plasma cells. The mean frequencies of VH+ plasma cells were 30% (MH-44), 17% (GB-24), 13% (NF-11), and 3% (SA-44), and similar frequencies were obtained for the VH+ B cell subpopulations. While subpopulations of B cells could be identified at all stages in differentiation by immunofluorescence with the anti-VH antibodies, neither resting nor activated T cells expressed these VH determinants in detectable amounts.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology*; D000939:Epitopes; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D009194:Myeloma Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D009194:Myeloma Proteins