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Biomedical subjects

M Pierres

Publications and source records attributed to M Pierres.

At least 91 records · Page 5Linked to original sources
PubMed1983

Structural bases for public idiotypic specificities of monoclonal antibodies directed against poly(Glu60Ala30Tyr10) and poly(Glu60Ala40) random copolymers.

NH2-terminal amino acid sequences of heavy and light chains of seven poly(Glu60Ala30Tyr10) (GAT) specific hybridoma products derived from DBA/2 and (DBA/2 X BALB/c)F1 hybrid mice and those of BALB/B polyclonal antibodies have been determined over the first 40 residues. Comparison of these sequences with those of nine other GAT or poly(Glu60Ala40) (GA) specific hybridoma products previously reported allowed the following conclusions. (i) Sequences of hybridoma H and L chains are present in the pool of polyclonal antibodies. (ii) The public CGAT (or pGAT) idiotypic specificities are strictly confined to antibodies exhibiting limited heterogeneity with regard to both the variable heavy (VH) and the variable kappa (V kappa) sequences that may be accounted for by one and two germ-line genes, respectively. (iii) The public idiotypic specificities GA-1, expressed by some anti-GAT and most anti-GA antibodies, make use of the same (or similar) VH germ-line genes as the CGAT or pGAT antibodies but possess a distinctive V kappa sequence. (iv) Antibodies expressing neither of the alternative public specificities mentioned above appear to be more heterogeneous and express VH and V kappa sequences that were found to differ from the basic structures defining the CGAT (pGAT) or GA-1 correlates. It is concluded that CGAT (or pGAT) and GA-1 public idiotypic specificities are germ-line markers of both VH and V kappa regions, an observation in agreement with previously reported serological data.

Animals↗
PubMed1983

Cross-reactions of anti-I-Ek monoclonal antibodies with subsets of I-Ab molecules.

Monoclonal antibodies H9-15.4 and H39-459 were derived from an A.TH anti-A.TL immunization. Antibodies H9-15.4 and H39-459 were found to be directed against the I-Ek molecule with positive reactions against B10.A (AkEk) and B10.S(9R) (AsEk) but not B10.A(4R) (AkEb). The monoclonal antibodies were also found to react with the b and q haplotypes, which do not express an I-E molecule. Sequential precipitation analysis showed that in the b haplotype, H9-15.4 and H39-459 react with the I-Ab molecule. These results showed that H9-15.4 and H39-459 recognize determinants shared by I-Ek and I-Ab molecules, suggesting that I-A and I-E molecules may have a common evolutionary origin, possibly through gene duplication. Sequential immunoprecipitation analysis of I-Ab molecules precipitated by H9-15.4 and H39-459 also suggested that these monoclonal antibodies recognize subsets of I-Ab molecules. Pretreatment with the 17-227 monoclonal anti-I-Ab antibody (Ia.15) had no effect on I-Ab molecules precipitated by H9-15.4 and H39-459. Also, pretreatment with H9-15.4 and H39-459 had no effect on I-Ab molecules immunoprecipitated by 17-227. Also H9-15.4 and H39-459 only partially cleared Ia molecules immunoprecipitated by each other. These results suggest that 17-227, H9-15.4, and H39-459 detect a minimum of four subsets of I-Ab molecules. To account for these observations, it is proposed that during evolution of the mouse H-2 complex, in addition to gene duplication of ancestral gene(s) to yield the genes encoding E alpha A alpha, A beta, and E beta polypeptide chains, further gene duplication occurred, forming multiple copies of genes encoding each Ia polypeptide chain.

Animals↗
PubMed1983

Analysis of the repertoire of anti-idiotypic B-cell responses to self-I-Ak- or -I-Ek-reactive monoclonal antibodies in A.TL mice.

Twenty anti-idiotypic antisera (anti-Ids) were produced in A.TL mice to self-I-Ak or -I-Ek-reactive monoclonal antibodies (mAbs), constructed in the A.TH anti-A.TL combination. The reactivity of these anti-Ids was examined in a panel of 31 anti-Iak A.TH mAbs, using direct idiotype binding, cross-competitive inhibition of idiotype binding, and isoelectrofocusing (IEF) assays. Among 13 anti-Ids produced against anti-I-Ak mAbs, one only recognized individual idiotypic specificities (IdIs) on its corresponding mAb, while the 12 others identified homologous IdIs and recurrent idiotypic specificities also expressed on heterologous anti-I-Ak and/or I-Ek mAbs. Two sets of major cross-reactive idiotypes (IdXs) were characterized on two groups of mAbs recognizing public Ia.1, I-Ak,f,u and r) or private (Ia.2, I-Ak) determinants clustered in two spatially distinct epitope regions of the I-Ak molecule, respectively. By contrast, most (5/7) of the anti-Ids raised against mAbs recognizing polymorphic or monomorphic (Ia.7-like) I-Ek determinants displayed specificity apparently restricted to their corresponding mAb IdIs. This finding contrasted with the previous characterization, using xenogeneic anti-idiotypic reagents, of an interstrain IdX expressed on all mAbs defining Ia.7-like determinants in the IEk epitope group I. These data indicate that A.TL mice can readily develop anti-idiotypic responses towards self Ia-reactive mAb minor idiotypes (IdIs) and that recognition of anti-Iak mAb IdXs in such mice is preferentially observed when anti-I-Ak mAbs are used as immunogens.

Animals↗
PubMed1983

Characterization of the murine antigenic determinant, designated L3T4a, recognized by monoclonal antibody GK1.5: expression of L3T4a by functional T cell clones appears to correlate primarily with class II MHC antigen-reactivity.

We describe here the properties of mAb GK1.5, which recognizes a cell surface molecule designated L3T4; the determinant on L3T4 recognized by mAb GK1.5 is designated L3T4a. We present evidence here that: i) the expression of L3T4a by murine T cell clones correlates primarily with class II MHC antigen-reactivity; ii) mAb GK1.5 blocks all class II MHC antigen-specific functions (cytolysis, proliferation, release of lymphokines) by murine class II MHC antigen-reactive T cell clones, although there appears to be clonal heterogeneity in the degree to which these functions are blocked by mAb GK1.5; iii) mAb GK1.5 blocks class II MHC antigen-specific release of IL-2 from cloned T cell hybridomas by blocking class II MHC antigen-specific binding; and iv) L3T4 is very similar to the human Leu3/T4 antigen. The properties of mAb GK1.5 (complement fixation, reactivity with all mouse strains tested, profound blocking of all class II MHC antigen-specific functions by murine T cells, usefulness for FACS analyses, and usefulness for immuno-precipitation/SDS-PAGE analyses) make it suitable for investigating both the role of class II MHC antigen-reactive T cells in various immunological phenomena and the mechanistic basis, at the molecular level, of class II MHC antigen-reactivity by murine T cells.

Animals↗
PubMed1983

Structural heterogeneity of the human Ia molecular pool as detected by cross-reacting mouse monoclonal antibodies.

Three monoclonal antibodies (Mab), H39.49.5, H40.242.3, and H40.164.3, produced in an A.TH anti-A.TL system and reacting with determinants expressed either on I-Ak, on I-Ek, or on I-Ak and I-Ek molecules, respectively, have been used to analyze, at the structural level, the molecules of the human Ia pool against which they cross-react. The results indicate that the human Ia pool can be dissected out by the use of the A.TH anti-A.TL Mab in distinct families, which display structural variations not only among each other but also with respect to the previously defined NG1 and NG2 Ia subsets. In two distinct Ia pools analyzed (from Raji cells: HLA-DR 3,W6, and from LG-2 cells: HLA DR 1,1), the three A.TH anti-A.TL cross-reacting antibodies recognized molecules in which the allelic polymorphism was confined to the beta subunits. Moreover, within the same Ia pool, the alpha subunits as well as the beta subunits were shown to be different from each other. These results are discussed in the context of the present knowledge of the heterogeneity of the human Ia pool and of the possible similarity between gene products of the mouse H-2-I region and the human HLA-D counterpart.

Antibodies, Monoclonal↗
PubMed1983

Clonal analysis of B and T cell responses to Ia antigens. IV. Proliferative T cell clones recognizing E beta and/or E alpha allodeterminants.

The allospecific T cell recognition of the I-Ek molecule was assessed by using eight A. TH anti-A. TL proliferative T cell clones, all of which expressed the Thy-1-2+, Lyt-1+, Lyt-2-, Ia-, and p94,180+ cell surface phenotype. The use of panels of stimulating cells from homozygous of F1 hybrid strains indicated each T cell clone exhibited specificity for distinct alloactivating determinants including: i) a private E beta k-controlled determinant expressed in cis- or trans-complementing E beta kE alpha strains; ii) an apparently nonpolymorphic E alpha determinant resembling the serologic specificity Ia.7, i.e., present in all strains carrying E alpha and E beta expressor alleles; and iii) a series of conformational I-E determinants, the expression of which required a precisely defined combinatorial association of E beta plus E alpha chains. Two clones were found to be reactivated by cis- but not trans-complementing E beta k E alpha k strains, and another recognized an allodeterminant shared by the I-Ab molecule. Various I-Ek-reactive monoclonal antibodies (mAb) directed to epitopes presumably expressed on either E alpha (epitope clusters I and II) or E beta (epitope cluster III) chains inhibited the proliferative responses of seven clones recognizing private E beta k or unique E beta E alpha conformational activating determinants. By contrast, the restimulation of the clone directed to a nonpolymorphic E alpha determinant was selectively blocked by anti-Ia.7 mAb defining epitopes on the E alpha chains but not by those directed to the E beta chain. On the basis of these data, it was concluded that the recognition sites of most anti-I-Ek proliferative T cells were expressed on the E beta chain or the E beta plus E alpha interaction products, and that a minority of such alloreactive T cells could be activated through recognition of the E alpha chain per se.

Alleles↗
PubMed1983

IA mutant functional antigen-presenting cell lines.

We describe a protocol for the selection of mutant cells with an altered pattern of Ia antigenic determinants and antigen-presenting properties from a homogeneous population of functional antigen-presenting cells (APC). The APC line used in this work was obtained by fusing lipopolysaccharide-stimulated B cells from (BALB/c x A/J)F1 donors with cells from the M12.4.1 BALB/c B lymphoma cell line. The resulting hybridomas, including TA3, retained the potent antigen-presenting activity of the parental B lymphoma line and expressed Ia antigens and immune response gene-determined antigen-presenting properties of the A/J type. Mutants of TA3 were obtained by subjecting the cells to negative immunoselection with one monoclonal anti-(alpha) 1-Ak antibody and complement followed by positive immunoselection via electronic cell sorting with a second monoclonal alpha I-Ak or alpha I-Ek antibody. Two types of mutants were obtained. One, A8, appeared to have undergone a fairly limited alteration, since it lost only some of the I-Ak antigenic determinants; the second type appeared to have lost the entire I-Ak molecule but to have retained the I-E molecule. Functional studies with the A8 mutant demonstrated that the loss of a limited number of I-Ak determinants correlated with the loss of a specific I-Ak-encoded restriction element, since A8 failed to present a specific antigen, hen egg lysozyme (HEL), to a HEL-specific I-Ak-restricted T cell hybridoma but retained some capacity to present a second antigen, poly(Glu60Ala30Tyr10) (GAT), to a GAT-specific I-Ak-restricted T cell hybridoma. These results indicate that Ia antigens are the products of immune response gene loci. The availability of such mutants should allow an examination of the relationship between the structure of an Ia molecule and the antigens with which it is co-recognized by T cells.

Animals↗
PubMed1983

Sharing of Ia antigens between species. IV. Interspecies cross-reactivity of monoclonal antibodies directed against polymorphic mouse Ia determinants.

The specificity of interspecies Ia cross-reactions has been analyzed by testing a panel of monoclonal antibodies (mAb) to mouse I-E and I-A antigens for reactivity with pig Ia antigens. Our earlier studies showed that mouse anti-I-E alloantisera recognized common determinants on Ia antigens of other species, whereas anti-I-A alloantisera showed much more limited cross-reactivity. These results were confirmed using a panel of 17 anti-I-E mAb, 10 of which were cytotoxic to pig cells. 2D gel electrophoretic analyses of precipitates with these mAb of 35S-labeled, NP40 solubilized pig cells revealed a limited set of protein spots that appeared to be identical to the subset of pig Ia antigens precipitated by A.TH anti-A.TL alloantiserum. Because the cross-reactive mouse sera were produced in mouse strains that do not express an I-E molecule (H-2b and H-2s), it was anticipated that the cross-reacting antibodies would be reactive with the monomorphic determinant of the I-E molecule, Ia.7. However, comparison of the reactivity of these mAb with pig cells and mouse cells revealed that the cross-reactivity on pig cells correlated not with Ia.7 but rather with detection of epitope(s) of the I-E molecule associated with inter-strain polymorphism. Anti-I-A cross-reactions were also detected, but were weaker and more limited. These findings may have implications for the evolution of Ia antigens in mammalian species.

Animals↗
PubMed1983

Characterization of the murine T cell surface molecule, designated L3T4, identified by monoclonal antibody GK1.5: similarity of L3T4 to the human Leu-3/T4 molecule.

Monoclonal antibody GK1.5 recognizes a previously undescribed murine T cell surface molecule, designated L3T4, which migrates on SDS-PAGE under reducing conditions as a single band with an apparent m.w. of 52,000. L3T4 is expressed by approximately 80% of thymocytes and by approximately 20% of spleen cells. There appears to be poor correlation between expression of L3T4 by functional T cell clones and expression of Lyt-2, expression of the cytolytic phenotype, and class I MHC antigen reactivity. On the other hand, both a class II MHC antigen-reactive HTL clone and an Lyt-1- Mls-reactive HTL clone express L3T4. Analysis of the effect of mAb GK1.5 on PFC responses in adoptive transfer suggests that L3T4 is expressed by the helper/inducer subset of murine T cells. Expression of L3T4 by murine T cells, however, may correlate primarily with class II MHC antigen reactivity rather than with functional phenotype; mAb GK1.5 profoundly blocks antigen-specific cytolysis by the cloned class II MHC antigen-reactive CTL line A15-1.17. Antigen-specific cytolysis by A15-1.17 is blocked by mAb GK1.5 at a step before the lethal hit. Collectively, the flow cytometric, functional, and biochemical data indicate that L3T4 is similar to the human Leu-3/T4 molecule.

Animals↗
PubMed1982

Inhibition of murine T cell-mediated cytolysis and T cell proliferation by a rat monoclonal antibody immunoprecipitating two lymphoid cell surface polypeptides of 94 000 and 180 000 molecular weight.

The monoclonal antibody methodology was use to identify membrane structures involved in T cell functions. To optimize chances to produce and detect relevant antibodies, a xenogeneic sensitization protocol was utilized and hybridoma supernatants were screened, on functional rather than structural grounds, for their ability to inhibit a given function. The test function was T cell-mediated cytolysis. Mouse cytolytic anti-allogeneic cell populations were used to sensitize a rat, the spleen cells of which were fused to produce hybridomas; the supernatants of the latter were screened for their ability to inhibit mouse T cell-mediated cytolysis in vitro. Several inhibitory antibodies were obtained, one of which, H35-89.9 monoclonal antibody, was studied in more detail. It inhibited specific and concanavalin A (Con A)-mediated cytolysis by T cells, by acting on the effector cells. It reversibly inhibited soluble antigen-, alloantigen and Con A-induced T cell proliferation (but not LPS-induced B cell proliferation), after the production of interleukin 2, by acting on the responder cells. It also had a desagglutinating effect on Con A and LPS blasts and on EL4 cells. In immunoprecipitated from thymocyte membrane preparations two structures of 94 000 and 180 000 apparent molecular weight, and recognized cell surface determinants on both T and B lymphocytes. Our findings suggest that several antibodies directed against distinct effector cell membrane structures inhibit cytolysis. The case of H35-89.9 monoclonal antibody, which exerts multiple functional effects and immunoprecipitates two membrane polypeptides, raises the problem of the various possible relationships between these structures and functions.

Animals↗
PubMed1982

Biochemical evidence for multiple Ia molecules.

Sequential immunoprecipitation and isoelectric focusing studies using anti-Ia monoclonal antibodies have shown multiple I-A and I-E Ia molecules. These studies suggest that the genes coding for Ia polypeptide chains A alpha, A beta, E beta and E alpha might have undergone further duplication and mutated. This would explain the diversity seen with Ia molecules in their ability to "present" numerous self and non-self antigens for generation of immune response.

Animals↗