Heavy and light chain variable region subgroups: antigenic analysis among human monoclonal immunoglobulins

Abstract

An antigenic analysis of human heavy and light chain variable region subgroups has been possible by means of heterologous specific antisera using a hemagglutination-inhibition procedure. The specificity of antisera had been shown to be directed against antigenic determinants of VkappaI, VkappaII, VkappaIII, VlambdaI, VlambdaII, VlambdaIII and VHIII by means of chemically subgrouped proteins. A series of IgG, IgA, IgM and IgD were examined for the presence of a VHIII variable region subgroup antigenic determinant. The data showed that 50% IgG, 62% IgA, 55% IgM, 45% IgD were positive for VHIII antigenic determinant. NH2 terminus blocked monoclonal immunoglobulin belonging to the VHIII subgroup were found, increasing incidence of this subgroup among IgG. A preferential association of VHIII antigenic determinant with IgG1, IgG3 subclasses was observed among IgG myeloma proteins while the preferential association was only observed with IgG1 subclass when anti-Rh antibodies were considered. Among 53 IgG of kappa type 20 (37%) kappaI, 30 (56%) kappaII, 3 (5%) kappaIII subgroups were found and among 42 IgG of lambda type 13 (31%) lambdaI, 13 (31%) lambdaII and 16 (38%) lambdaIII were observed. Although numbers are limited in each group for conclusions a study of VHIII and non VHIII antigenic subgroup determinant with respect to the light chain subgroups is given. The non-allelic behaviour of this VHIII antigenic determinant was observed. Preliminary data on the presence of these human antigenic determinants among different animals species were given.