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M J Bosma

Publications and source records attributed to M J Bosma.

69 records · Page 4Linked to original sources
PubMed1981

T lymphocytes specific for immunoglobulin allotype. II. Cloned Igh-1b-specific cytotoxic T cells.

This study describes long-term-cultured lines and clones of cytotoxic T cells (Tc) with specificity for determinants of the Igh-1(b) immunoglobulin allotype. These Tc clones were initiated by repeated stimulation of immune spleen cells from BALB/c mice with an Igh-1(b)-producing myeloma, and then they were maintained in medium supplemented with mitogen-induced growth factors in the absence offurther antigenic stimulation . The lytic potency of these clones was 30-100-fold greater than the primary cultures from which they were derived, and specificity studies showed them to be lytic for Igh-1(b) targets and not for targets expressing Igh-1(a) or Igh-4(b), nor the lipopolysaccharide blasts . Finally, soluble preparations of Ig were tested for their ability to block lysis of labeled Igh-1(b)-expressing targets. The results showed that Igh-1(b) and not other immunoglobulin allotypes or isotypes could block lysis, and that the mechanism of lytic inhibition is due to Igh-1(b)-induced autolysis of the killer cells.

Antibody Specificity↗
PubMed1980

Concentration of IgG1 and IgG2a allotypes in serum of nude and normal allotype-congenic mice.

BALB/c (C) and C57BL/6 (B6) allotype--congenic strains of mice (C, C.B, B6, B6.C) were made congenitally anthymic by the introduction of the mutant nude gene (nu). The resulting nude mice (C.nu, C.B.nu, B6.nu and B6.C.nu) were found to produce highly variable quantities of IgG1 and IgG2a. Whether these mice showed high, normal, or low quantities of IgG1 or IgG2a relative to their normal counterparts depended on their age and genetic background. In all nude mice, IgG1 production appeared more sensitive to the loss of T cells than did IgG2a production. An extreme example of this was the deficiency of IgG1 but not IgG2a in adult B6.nu and B6.C.nu mice. Substantial quantities of both IgG1 and IgG2a were found in adult C.nu and C.B.nu mice.

Aging↗
PubMed1980

Dominance of an immune response by secondary cells: quantitation by allotype analysis.

Dominance of an immune response by secondary cells was demonstrated in a cell transfer system utilizing allotype-congenic mice. Spleen cells from BALB/c mice immunized with TNP-KLH were adoptively transferred into sublethally irradiation (200 R) congenic partners of a different allotype (C.B.-17 mice). Subsequent to the cell transfer, the recipients were challenged with TNP-KLH and bled periodically. Anti-TNP antibodies were isolated and analyzed for their content of donor and host IgG allotypes. Through day 58 after the adoptive transfer, 80% or more of the IgG antibody measured was of donor allotype. By day 110, most but not all recipients made IgG antibody principally of host allotype. In contrast, control C.B-17 recipients, which received nonimmune BALB/c spleen cells but otherwise treated as above, produced IgG antibodies almost entirely of host allotype. Total anti-TNP synthesis was reduced markedly in recipients of immune BALB/c cells so that there was a decrease of about 95% in the production of anti-TNP antibodies of host allotype, as compared with controls that received nonimmune cells. The results are discussed in terms of dominance of an immune response by secondary B cells.

Animals↗
PubMed1979

Radioimmune analysis of an unexpected mouse allotype.

We have used a radioimmune assay to confirm our earlier findings of an unexpected immunoglobulin allotype in Igb-congenic BALB/c mice. Although these mice were bred to exclude the IgG2a allotype of BALB/c (Ig-la), an Ig-la-like antigen was detected in the 7S Ig fraction of two (of five) pooled serum samples, it represented 0.1--0.3% of the total 7S protein and was indistinguishable from a reference Ig-la. The detection of putative Ig-la in Igb-congenic mice is inconsistent with the notion that allotypes are products of allelic structural genes. It appears rather that expression of Ig-la is controlled by allelic regulator genes and that its low and transient production in Igb-congenic mice results from incomplete negative regulation.

Animals↗
PubMed1978

Prevention of immunoglobulin production by allotype-dependent T cells.

Adoptive lymphocyte transfers between Iga, Igb and Igd allotype-congenic mouse strains revealed host barriers against the production of certain donor allotypes. First, as recipients of Igb cells, Iga and Igd mice permitted the production of donor Ig-4b but not that of Ig-1 b. The apparent mediators of this Ig-1 b barrier were T cells specific for Ig- 1 b determinants on B cells. Additional cell transfers showed Iga mice to have a second barrier against allotype production by Igd donor cells. Reciprocal cell transfers showed Igb and Igd mice to have comparatively weak barriers against Iga-producing cells. As host barriers were absent in mice deficient for T cells (athymic nude mice), it appears that they are T cell-mediated. Further, the allotype-dependence of such barriers means that the antigens responsible must be under the control of allotype-linked genes. The regulatory implications of this for the immune system are discussed.

Animals↗
PubMed1977

Serological distinciton of heavy chain variable regions (VH subgroups) of mouse immunoglobulins. I. Common VH determinants on the heavy chains of mouse myeloma proteins having different binding sites.

16 of more than 100 mouse myeloma proteins, including 3 proteins of the IgG2a class and 13 of the IgA class, were shown to have a similar heavy chain variable region (VH) antigen(s) (U10-173). The proteins bearing these antigenic determinants (U10-173+ proteins) represented at least five different ligand-binding specificities. These findings, taken togeter with available sequence data for VH regions of U10-173+ proteins, have led us to conclude that U10-173 defines a small number of related VH subgroups. The ability to detect VH subgroups in mice by serological means, as has been done in humans also, promises new and useful kinds of VH markers for immunologic study.

Animals↗
PubMed1977

Prevention of IgG2a production as a result of allotype-specific interaction between T and B cells.

BALB/c T cells, which can prevent normal C57BL IgG2a allotype (G2) production of Ig-congenic partner mice (C.B mice), are shown capable of preventing the growth and G2 production of a C.B plasmacytoma (CBPC 101). Such cytotoxic or suppressor T cells are clearly allotype-specific (G2 Tcs cells). And since CBPC 101 B cells do not require specific helper T cells in order to grow, we infer that G2-bearing B cells (normal or neoplastic) must be the direct target of G2 Tcs cells. This mode of T cell prevention of allotype production contrasts that reported for suppressor T cells in (BALB/c x SJL)F1 mice.

Animals↗
PubMed1977

Clones producing antibodies of more than one class.

Clones producing antibodies directed against oligo-D-alanine (D-ala) determinants have been demonstrated in X-irradiated recipient mice after transfer of limited numbers of spleen and thymus cells. Seven out of eighty-one recipients were found to have donor allotype clones, all of which produced IgG1 antibodies to D-ala; two of these clones also produced small quantities of IgG2a antibodies. In addition, each of the seven responder mice contained IgM antibodies to D-ala. Isoelectric focusing (IEF) patterns of anti-D-ala antibodies from each of the seven responder mice were restricted and compatible with one to three antibody types. Most of these IEF patterns were significiantly different from each other. Five mice have been used for a comparison of IgM and IgG1 combining sites by affinity and specifity measurements. In each case affinity and specificity of IgM and IgG1 antibodies were alike. No similarity was found when comparing IgM from one clone with IgG1 from another one. These data led us to conclude that a single precursor cell can give rise to a clone producing antibodies of the IgM class and different IgG subclasses all of which share combininig sites.

Animals↗
PubMed1975

Alteration of immunoglobulin phenotype in cell culture-adapted lines of two mouse plasmacytomas.

Murine plasmacytomas can be adapted to continuous in vitro culture by alternate passage between culture and animal. We have found that the kinetics of adaptation reflect a selection for the growth of variant plasmacytoma cells. The inclusion of an altered immunoglobulin phenotype in such variant cells could explain the Ig-producing variants that we observed in two of six transplantable lines of plasmacytomas that were adapted to culture. The first variant, an IgM-producing cell line (104-76), was adapted from a transplanted line of MOPC 104E that had stopped producing IgM with binding specificity for alpha1-3 Dextran. Unlike MOPC 104E, the IgM of 104-76 contains kappa- instead of lambda-light chains and probably contains an altered or different mu-heavy chain. A second variant (352-57) was found in an IgG2b-producing tumor (MOPC 352) which was induced in a BALB/c mouse strain (CB-6) that carried Ig genes of the C57BL/Ka allotype. This cell line apparently switched from producing IgG2b molecules of the C57BL allotype (H9) and of a known idiotype to IgG1 molecules of the BALB/c allotype (F19) without the idiotype marker. The propagation of a biclonal plasmacytoma from the time of original tumor induction does not appear as a likely explanation for these results. Rather, we seem to be dealing with plasmacytoma variants or with the possible induction of secondary tumors of host origin.

Animals↗
PubMed1975

Quantitation of mouse immunoglobulin allotypes by a modified solid-phase radioimmune assay.

Allotype-reactive polystyrene tubes were made by first coating their inner surface with immunglobulin (Ig) solutions containing the allotype of interest; this was followed by the application of anti-allotype antibody. The latter was covalently cross-linked to the adsorbed allotype antigen by means of glutaraldehyde to prevent the dissociation of antibody from the surface of the tube in subsequent steps (glutaraldehyde treatment did not affect the specificity of these tubes). Under conditions of antibody excess, allotype-reactive tubes were treated next with 125I-labeled 7S Ig from standard solutions in order to estimate the concentration of Ig allotypes in these solutions. Then, to determine serum allotype concentrations, we used the standard solutions and the serum unknown to carry out competition experiments between labeled and unlabeled allotype antigen. Quantitation of serum Ig allotypes in this way featured a high signal to noise ratio (30 to 100), an error estimate of 3 to 7%, and sensitivity in the nanogram range.

Animals↗
PubMed1974

Congenic mouse strains: the expression of a hidden immunoglobulin allotype in a congenic partner strain of BALB-c mice.

This paper derives from the unexpected observations of the "wrong immunoglobulin allotype" in a congenic partner strain of BALB/c mice from the Institute of Cancer Research (ICR CB-17). These mice were specially bred so as not to differ from BALB/c mice in any known way except to carry immunoglobulin structural genes of the C57BL/Ka allotype. In this respect, ICR CB-17 mice were defined as allotypically homozygous according to the Mendelian inheritance of mouse allotype markers. The homozygosity of these mice was challenged, however, when in certain instances immunoglobulins of the BALB/c allotype appeared in the serum of some ICR CB-17 mice. The appearance of this hidden allotype was usually transient and only associated with immunoglobulins of the IgG (IgG2a) class. The implications of these findings for the inheritance and expression of immunoglobulin structural genes are discussed.

Animals↗