title: Sporadic idiotypic cross-reactivities between antibodies and T helper cells: one example of aleatory expression of T cell idiotypes.
abstract: Idiotypic cross-reactivities between T and B cell receptors have been taken in the past to suggest VH-gene expression by both types of lymphocytes. More recently, after the molecular characterization of TcR, those observations were reinterpreted to indicate idiotypic network regulation, operating to select cross-reactive idiotypes in both B and T cell compartments. In support of these views, it has been shown that T cell expression of idiotypes is controlled by IgH-linked genes and markedly altered in B cell-deprived mice, and that T cells "learn" idiotype expression from the B cell compartment in the first few weeks of life. In most of these studies, aleatory idiotype cross-reactivities have not been sufficiently considered. Given the large diversity of antibodies and TcR, and the degeneracy of antibody-ligand interactions, it could be expected that a (monoclonal) anti-idiotypic reagent prepared against an antibody idiotope will always "cross-react" with some TcR variable regions. If these will be "major" T cell clonotypes, situations of idiotype sharing by B and T cells can be found which indicate neither VH-gene expression by T cells nor idiotypic network regulation. We report here one example of such aleatory expression of antibody idiotypes by T lymphocytes. A monoclonal anti-idiotypic antibody directed to anti-TNP antibodies of BALB/c mice specifically inhibits the growth and effector activity of C57BL/6 anti-NP-self helper T cells, while failing to interact with either BALB/c anti-NP-self or C57BL/6 anti-TNP-self helper cells. The clonotypic nature of these interactions could also be demonstrated by the specific induction of IL-2 production in the appropriate helper T cells by the anti-idiotypic antibody.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Immunology, Clinica Puerta de Hierro, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Martinez
authors.forename: A
authors.initials: A
authors.lastname: Coutinho
authors.forename: A
authors.initials: A
authors.lastname: Bandeira
authors.forename: A
authors.initials: A
authors.lastname: de la Hera
authors.forename: M
authors.initials: M
authors.lastname: Toribio
authors.forename: M A
authors.initials: MA
authors.lastname: Marcos
authors.forename: P
authors.initials: P
authors.lastname: Pereira
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D003429:Cross Reactions; D005803:Genes, Immunoglobulin; D007130:Immunoglobulin Idiotypes / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D051379:Mice; D008815:Mice, Inbred Strains; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D007130:Immunoglobulin Idiotypes; D007376:Interleukin-2; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell