Search PubMed⌕ Search

Biomedical subjects

B Bogen

Publications and source records attributed to B Bogen.

At least 55 records · Page 3Linked to original sources
PubMed1993

Processing and presentation of idiotypes to MHC-restricted T cells.

Among the self antigens, immunoglobulins, and in particular idiotypes, are of special interest because of their extreme sequence heterogeneity and their postulated involvement in regulatory interactions in the immune system. We have therefore studied antigen processing and presentation of variable region peptides, processed idiotypes, to MHC class II molecule-restricted T cells. The immunoglobulin used has been the lambda 2(315) light chain produced by the BALB/c MOPC 315 plasmacytoma (alpha, lambda 2). The minimum length of a stimulatory synthetic idiotypic peptide comprises residues 91-101 of lambda 2(315) and is presented by the I-E(d) molecule to CD4+ T cells. T cell clones with specificity for the 91-101(lambda 2(315))/I-E(d) complex utilize a limited TCR repertoire and are of both Th1 and Th2 type. For presentation, extracellular lambda 2(315) requires endocytosis and processing, as previously described for conventional exogenous antigens. In addition, a B lymphoma cell can process and present its own endogenous lambda 2(315). This was shown by transfecting manipulated lambda 2(315) gene variants into B lymphoma cells, followed by evaluation of the APC function of the transfectants. These studies demonstrated that surface expression or secretion of lambda 2(315) is not necessary for presentation and suggested that the endoplasmic reticulum may be a processing compartment. To extend our findings to naive Id+ B cells and anti-Id T cells, we have generated lambda 2(315)-transgenic as well as TCR-transgenic mice. A model is presented for a T-B cell interaction based on presentation of processed idiotypes.

Amino Acid Sequence↗
PubMed1992

Weak positive selection of transgenic T cell receptor-bearing thymocytes: importance of major histocompatibility complex class II, T cell receptor and CD4 surface molecule densities.

We have produced alpha beta T cell receptor (TcR)-transgenic mice and studied MHC-dependent positive selection of T cells bearing this receptor. The alpha and beta transgenes were isolated from an I-Ed-restricted, CD4+ BALB/c (H-2d/d) T cell clone specific for a peptide consisting of the 91-101 residues of the lambda 2 immunoglobulin light chain of MOPC315. Mice which carry the transgenes on a BALB/c background, but with H-2d/d, H-2b/d or H-2b/b major histocompatibility complex (MHC) haplotypes, were investigated for TcR expression in thymocytes and peripheral T cells. The thymocytes expressing the transgene-encoded alpha beta receptor are weakly positively selected when compared with previous findings in other TcR-transgenic mice models. Thus, alpha beta thymocytes vary in their efficacy of being positively selected by their restriction element. Furthermore, the density of TcR and CD4 on thymocytes, as well as the density of I-Ed molecules on thymic epithelial cells, appear critical for the extent of positive selection. A possible explanation is that the transgenic TcR has a marginal affinity for self-MHC molecules on thymic epithelium, and that this may be compensated for by an increase in the number of CD4/TcR/MHC ternary complexes forming between the maturing thymocyte and the cortical epithelial cells.

Animals↗
PubMed1992

Restricted alpha/beta receptor gene usage of idiotype-specific major histocompatibility complex-restricted T cells: selection for CDR3-related sequences.

We have sequenced the T cell receptor (TcR) V alpha and V beta genes of seven independent BALB/c CD4+ T cell clones specific for the immunoglobulin lambda 2 light chain produced by the MOPC 315 myeloma (lambda 2(315)). All the clones recognize a peptide of residues 91-101 of lambda 2(315) and are restricted by the major histocompatibility complex (MHC) molecule I-E(d). The results indicate that in BALB/c mice, this anti-idiotypic response uses a very limited number of TcR. The four clones which cross-react between Phe94 and Tyr94 peptide analogues use very similar receptors (V alpha 3, J alpha 1, V beta 6, J beta 1.1). The V alpha 3 gene used by all of these clones is identical and has not been previously described. Although the four clones differ in nucleotide sequence in the V/J borders, two had identical receptors at the amino acid level. One of the cross-reactive clones exhibits a heteroclitic response to the Tyr94 peptide variant resulting from a single amino acid exchange in the V/J junction of the alpha chain. The three remaining clones which recognize only the Phe94 and not the Tyr94 peptide have somewhat more diverse TcR, however, two of these three clones use V beta 6. One of these non-crossreacting clones is alloreactive, the specificity of which can be attributed to differences in the N-D-J sequences. Taken together these data indicate that this T cell response to an immunoglobulin idiotope is very restricted in terms of the TcR used. These data in conjunction with recently published results indicate that, although there can be strong preference for individual V alpha or V beta gene segments, certain V alpha/V beta combinations are preferentially selected for interacting with a given peptide/MHC combination, and that the CDR3-related regions are crucial for antigen fine specificity and alloreactivity.

Amino Acid Sequence↗
PubMed1992

A Tcra congenic mouse: V alpha epitope expression is influenced by both Tcra haplotypes and background genes.

A T-cell receptor alpha chain locus (Tcra) congenic mouse is described. The Tcraa haplotype of BALB/c (donor strain) was bred on to B10.D2 (background strain, Tcrab haplotype) by using a Bgl I Tcra-C restriction fragment length polymorphism. Tcraa/b heterozygous offspring from the eleventh backcross generation were brother-sister mated to obtain Tcra-Ca homozygous animals. The resulting congenic line, B10.D2.C-Tcraa/Bo carries a recombination between the Tcra and the hr loci; thus, the transferred differential segment is the centromeric 18-27 cM of the BALB/c chromosome 14. Analysis with a multitude of Tcra-V and Tcrd-V probes demonstrates that the complete Tcraa haplotype is contained within this differential segment. Lymph node T cells of BALB/c (Tcraa) B10.D2 (Tcrab) and B10.D2.C-Tcraa were stained with anti-V alpha 8 (KT50, KT65), anti-V alpha 3.2 (RR3-16) and anti-V alpha 11.1 and 2 (RR8-1) monoclonal antibodies. We find that the frequencies of V alpha epitope expression are highly Tcra haplotype-dependent even though an influence of background genes is also observed. Thus, Tcra-V germline differences may possibly influence the T cell repertoire, in addition to the already well known positive and negative thymic selections. Tcra haplotype does not influence the frequencies of V beta utilization. However, BALB/c mice have fewer V beta 11+ T cells than B10.D2 and B10.D2-Tcraa, therefore, the BALB/c genome must harbor a V beta 11 deleting gene(s) in addition to those described so far.

Animals↗
PubMed1991

MHC class II-restricted presentation of intracellular antigen.

An endogenously produced immunoglobulin light chain (lambda 2(315] is processed and presented to T cells in association with major histocompatibility complex (MHC) class II molecules. Using transfectants producing variant forms of lambda 2(315) that are neither expressed on the cell surface nor secreted, we demonstrate that intracellular lambda 2(315), which has never been exported outside of the cell, is the source of processed lambda 2(315) idiotype. This challenges the currently accepted paradigm that endogenous antigens are only presented by MHC class I molecules. Variants of lambda 2(315) protein that are retained in the endoplasmic recticulum (ER) are also presented. Variants that are expressed in the cytosol as well as those that are transported into the nucleus rather than the ER are not presented. Thus, the ER is likely to be the processing compartment.

Animals↗
PubMed1991

A rearranged lambda 2 light gene chain retards but does not exclude kappa and lambda 1 expression.

Mice transgenic for the lambda 2 light chain of MOPC315 were established. In newborn transgenics (TG), lambda 2 was the only light chain found on B cells. However, by day 21, lambda 2 high kappa low as well as lambda 2 low kappa high double expresser populations were emerging. lambda 2 was found on an increased fraction of serum immunoglobulins (Ig), this fraction declined with age. Correspondingly, kappa and lambda 1 expression was suppressed in young mice but increased with age. In adult mice kappa or lambda 1 were often co-expressed with lambda 2 in single serum Ig molecules. Most B cell hybridomas from and adult TG secreted lambda 2,kappa mixed molecules and had rearranged their kappa chain genes. One lambda 2,lambda 1 hybridoma and even a lambda 2,kappa,lambda 1 hybridoma were also found. In conclusion, isotypic exclusion in lambda 2 TG is complete in newborns but becomes increasingly leaky with age. Antigen probably expands the lambda 2 low kappa high B cell population; this population is most likely the major source of serum Ig in adult lambda 2 TG mice. In contrast, the lambda 2 high kappa low population, a major fraction of which is CD5+ Mu low delta low, appears only infrequently to develop into antibody-secreting plasma cells.

Animals↗
PubMed1991

Idiotype-specific, major histocompatibility complex restricted T cells are of both Th1 and Th2 type.

The lymphokine secretion patterns of seven independent 91-101.lambda 2(315)/I-Ed specific, CD4+ T-cell clones have been investigated. Six of the clones are of the Th1 type as they secrete IL2 and IFN gamma, but not IL4. Some of these six Th1 clones produce TNF alpha/beta, and some produce minor amounts of IL5 and IL6. One clone is of the Th2 type as it produces IL4, IL5, and large amounts of IL6, but not IL2, IFN gamma or TNF. The Th1/Th2 classification does not have any stringent relationship to immunization protocol, fine specificity and V alpha/V beta gene segment utilization. The immunoregulatory significance of our findings for Id/MHC-dependent T-B cell interaction is discussed.

Animals↗
PubMed1990

A stimulatory monoclonal antibody detecting T cell receptor diversity among idiotype-specific, major histocompatibility complex-restricted T cell clones.

A panel of independent BALB/c T cell clones responding to a peptide of the lambda 2(315) immunoglobulin light chain (residues 91-101), in the context of I-Ed, has previously been described. A monoclonal antibody (mAb; GB113) to the T cell receptor (TcR) of one of the clones, 4B2A1 (V alpha 1, J alpha 19; V beta 8.2, D beta 1.1, J beta 1.2) precipitates the alpha/beta heterodimer from 4B2A1. However, GB113 does not bind DO11-10.2 cells bearing a similar alpha/beta heterodimer (V alpha 1.1, J alpha TT11; V beta 8.2, D beta 1.1, J beta 1.1). GB113 does not cross-react with the TcR of the six other clones in the panel. Furthermore, the mAb does not bind polyclonal lambda 2(315)-specific T cell lines except 4.4% of cells of line 4 from which 4B2A1 was cloned. The mAb only binds a negligible number (0.5%) of BALB/c thymocytes and peripheral T cells. Therefore, the epitope detected by GB113 is very rarely expressed on 91-101. lambda 2(315)-specific TcR or on TcR of normal T cells. Soluble GB113 induces T cell activation [measured as proliferation and interleukin (IL) 2, IL3 and interferon-gamma production]. GB113-induced T cell activation is enhanced by soluble anti-CD4 and anti-Thy-1 mAb.

Animals↗
PubMed1990

No recombinations between Tcra-V and Tcra-C gene segments in 669 backcross mice.

Because T-cell receptor (Tcr) genes may possibly function as non-major histocompatibility complex (MHC) immune response genes or predispose for autoimmune diseases, it is important to know how these genes are inherited. We found that Bgl I-digested DNA of BALB/c, C3H, DBA/2, and C57BL/6 exhibited restriction enzyme fragment length polymorphisms (RFLPs) for the Tcra-V1, Tcra-V2, Tcra-V4, Tcra-V6, Tcra-V7, Tcra-V8, Tcra-V11, Tcra-V12, Tcra-V13, and Tcra-C gene segments. Inheritance of these RFLPs in 669 offspring from (BALB/c x C57BL/6) x BALB/c, (BALB/c x C57BL/6) x C57BL/6, (C57BL/6 x DBA2) x DBA/2, and (C57BL/6 x C3H) x C3H backcrosses was studied. Since we did not find any recombinations in the offspring, Tcra-V and Tcra-C gene segments are tightly linked and inherited as a haplotype. A peculiar finding was that 22 out of 103 (BALB/c x C57BL/6) x BALB/c offspring, heterozygous for Tcra-C, had deleted a C57BL/6 Tcra-V1 band as well as Tcra-V2 and Tcra-V4 bands. As will be discussed, this deletion is probably caused by heterogeneity in the C57BL/6 breeding stock of a commercial supplier. In seven BXD and BXH recombinant inbred strains with known recombinations between the Tcra-C and Es-10 loci, all Tcra-V RFLPs cosegregated with the Tcra-C RFLP. This finding agrees with the conclusion from our backcross studies; namely that Tcra-V and Tcra-C gene segments are tightly linked.

Animals↗
PubMed1989

Minimum length of an idiotypic peptide and a model for its binding to a major histocompatibility complex class II molecule.

We have defined the minimum length of a synthetic peptide which can activate I-Ed-restricted BALB/c T cell clones specific for a mutated self-antigen: an idiotope on the syngeneic lambda 2315 immunoglobulin light chain. A peptide comprising residues 91-101 of the lambda 2315 sequence had full stimulatory potency. Surprisingly, a peptide analogue in which His97 was deleted was almost fully active. Truncated, deleted or substituted peptide analogues did not distinguish between seven T cell clones that use different alpha/beta T cell receptors. The 91-101 region in the lambda 2315 light chain does not form an amphipathic helix even though such a helix has been suggested to be important for T cell epitopes. Further, a motif proposed by Rothbard and Taylor as being common to T cell immunogenic peptides is not necessary for the lambda 2315 idiotypic peptide. Comparison with seven other I-Ed-restricted peptides revealed that the peptides are generally positively charged and have two basic amino acids clustered around the centre. On the basis of a model of the class II molecule peptide binding site, we suggest that these positively charged residues may interact with the negatively charged residues at positions 114(Glu) and 155(Asp) of the E beta d chain.

Amino Acid Sequence↗
PubMed1989

B-lymphoma cells process and present their endogenous immunoglobulin to major histocompatibility complex-restricted T cells.

Antigen-presenting B-lymphoma cells were transfected with the gene encoding the immunoglobulin lambda 2 light chain of MOPC315 cells (lambda 2(315). The lambda 2 chain is expressed on the cell surface of the transfectants together with the endogenous heavy chain. The transfectants present an idiotope of the lambda 2(315) light chain to class II-restricted T-cell clones. Recognition by the T cells requires processing of the lambda 2(315) light chain. From these data we conclude that B-lymphoma cells constitutively process and present their immunoglobulins. Secretion and reuptake of the light chain was not necessary for the presentation. Thus, B cells bear two types of idiotypes on their membrane, a native form as surface immunoglobulin and a processed form in the context of products of the major histocompatibility complex.

Animals↗
PubMed1989

Monoclonal antibodies specific for variable and constant domains of murine lambda chains.

Rat monoclonal antibodies directed against the BALB/c myeloma protein M315 (alpha,lambda 2) are described. 9A8 (IgG1) binds the V domain of lambda 2 and cross-reacts with lambda 1 and lambda 3 chains. 2B6 (IgG2a) is directed to the C domain of lambda 2 and cross-reacts with C lambda 3. The antibodies bind isolated chains as well as complete immunoglobulins. The monoclonals detect soluble immunoglobulin (radioimmunoassay), immunoglobulin immobilized on polystyrene (enzyme-linked immunosorbent assay), immunoglobulin bound to nitrocellulose (immunoblotting), and surface immunoglobulin intercalated in cell membranes (immunofluorescence). The antibodies are easily purified on protein G immunosorbents and may be biotinylated or conjugated with fluorescein isothiocyanate without loss of capacity to bind. In addition to the anti-lambda antibodies, a C alpha 2/C alpha 3-specific monoclonal antibody, 8D2 (IgG2a) is described.

Animals↗
PubMed1986

Idiotope-specific T cell clones that recognize syngeneic immunoglobulin fragments in the context of class II molecules.

We have established idiotope (Id)-specific T cell lines and clones derived from at least 4 different BALB/c mice immunized with the light chain (lambda 2(315] of the BALB/c myeloma protein M315 (alpha, lambda 2). Independently derived clones were indistinguishable in that they reacted to V lambda 2(315), one or more of the amino acids corresponding to somatically mutated codons 94, 95 and 96 of the third hypervariable region being essential for expression of the Id. While the Id was efficiently expressed on V lambda 2(315), Fv315 and lambda 2(315) fragments, about a 100-1000-fold higher molar concentration of Fab315 and M315 was needed to induce equivalent responses. Thus, Ig quaternary structure heavily influenced the availability of the Id for T cells. The V lambda 2(315)-specific T cells were Thy-1.2+, L3T4+, Ly-2.2- and I-Ed restricted. Some of the T cell clones produced interleukin 2 (IL2), IL3 and B cell growth and differentiation factors upon activation. In addition, T cells were cytotoxic in long-term assays for Ed beta Ek alpha-, but not Ek beta Ek alpha- transfected L cells in the presence of Id. The cytotoxic effect was the basis for an L cell growth inhibition assay for T cell activation that was at least 10-fold more sensitive than ordinary proliferation assays.

Animals↗
PubMed1986

Synthetic peptides and beta-chain gene rearrangements reveal a diversified T cell repertoire for a lambda light chain third hypervariable region.

Twelve L3T4+ Ly-2.2- subclones, derived from 4 independent BALB/c T cell lines, responded to a combination of the I-Ed molecule and a synthetic peptide corresponding to residues 91-108 of the lambda light chain from BALB/c myeloma protein M315 (alpha, lambda 2). Peptide analogues in which the mutated residues Arg95 or Asn96 were exchanged with the corresponding germ-line-encoded Ser95 or Thr96 had an abolished or greatly reduced capacity to stimulate T cell clones. However, responses of subclones to an analogue where the mutated Phe94 was substituted with the germ-line-encoded Tyr94 revealed three specificity patterns: 5 clones reacted only with the lambda 2(315) peptide, 6 clones responded equally well to both peptides and a single clone reacted better with the Tyr94 analogue. Analysis of the T cell receptor beta-chain gene rearrangements disclosed 7 distinct rearrangements, identical rearrangements only being found for subclones originating from the same line. At least 3 different V beta genes were used. Subclones with identical or nearly identical peptide specificity, major histocompatibility complex-restriction and alloreactivity could differ in their V beta or J beta gene segment utilization.

Amino Acid Sequence↗
PubMed1985

T helper cell recognition of idiotopes on lambda 2 light chains of M315 and T952: evidence for dependence on somatic mutations in the third hypervariable region.

Previous work has indicated that BALB/c T helper cells (Th) recognize an idiotope expressed on a 88-114/117 fragment of V lambda 2 of BALB/c myeloma protein 315. In the present study the antigenic structure of this idiotope was further analyzed. Conventional carrier-specific Th elicited by immunization of BALB/c mice with free lambda 2(315) did not cross-react with the free lambda 2 chain of the BALB/c myeloma protein T952 which differs from lambda 2(315) in five amino acid positions (38, 94, 95, 96, 99). Similarly, Th primed with free lambda 2T952 did not respond to a boost with free lambda 2(315). Thus, BALB/c lambda 2(315)-specific Th recognize an idiotope that depends on some or all of the residues at positions 94, 95, 96 and 99. Furthermore, free lambda 2T952 contains an idiotope immunogenic to Th that depends on some or all of residues 38, 94, 95, 96 and 99. Th recognition of the free lambda 2T952 idiotope was quenched upon H + L chain assembly because Th elicited by free lambda 2T952 did not respond to a boost with the complete T952 myeloma protein. In contrast to the lack of Th cell cross-reactivity, some of the antisera from BALB/c mice immunized with free lambda 2T952 cross-reacted with free lambda 2(315), free lambda lJ558 and free lambda 3CBPC49 but not with free kappa W3129 or polyclonal L chains. The H chain of T952 (alpha, kappa 2) myeloma protein was abnormally short (Mr = 48 000) and T952 existed as a halfmere probably due to this H chain deletion. Furthermore, H and L chains were disulfide bonded to each other.

Animals↗
PubMed1985

Dominant suppressive effect of the silent Eb alpha allele on an in vivo T helper cell response under Ed beta Ed alpha region-linked immune response gene control.

Previous adoptive spleen cell transfer experiments have demonstrated that an immune response (Ir) gene linked to the Ed beta Ed alpha region allows BALB/c T helper lymphocytes (Th) to respond to an idiotope on the V lambda 2(315) fragment of isologous myeloma protein M315. BALB.K (H-2k) and BALB.B (H-2b) do not respond to V lambda 2(315). While (H-2d X H-2k)F1 hybrids have been shown to be responders, it is now demonstrated that (H-2d X H-2b)F1 hybrids are low responders. By crossing BALB/c with various H-2 recombinants on B10 background and probing Th responsiveness to V lambda 2(315) in these F1 hybrids, the dominant suppressive gene of the H-2b haplotype is mapped to Eb alpha Sb. It is argued that the suppressive gene is Eb alpha, which is a silent allele. A likely explanation for the suppressive effect of the Eb alpha allele is that reduced amounts of Ed beta: Ed alpha restriction elements are present on antigen-presenting cells of (H-2d X H-2b)F1 hybrids because only one E alpha gene is functional in such mice. The present report extends previous in vitro findings from other laboratories to the in vivo situation and suggests that silent alleles for class II molecule chains may profoundly affect certain immune responses of individuals heterozygous for the silent allele.

Alleles↗
PubMed1985

H-2-linked Ir genes have a striking influence on the immunogenicity of idiotopes of myeloma protein 315 for T helper cells.

H-2-linked immune response (Ir) genes control T helper cells (Th) that recognize idiotopes of the V domains of myeloma protein 315 as carriers; Th recognition was detected by augmentation of antibody responses of hapten (4-hydroxy-3-iodo-5-nitrophenylacetyl (NIP]-primed B cells boosted with NIP conjugated to Fab315. The present study indicates that the responder k allele of the Ir VH315 gene maps to the I-A subregion of H-2. A responder s allele of the Ir V lambda 2(315) gene on an A-strain background was identified, which also most likely maps to I-A. Although the d allele of the Ir V lambda 2(315) gene is a responder allele on DBA/2 background, the D2.GD strain (with I-region haplotype AdBbJbEbCb) was non-responder to V lambda 2(315), suggesting either that the responder d allele maps to I-E or that the b allele of a second Ir V lambda 2(315) gene located to the right of I-A exerts a strong suppressive influence. The H-2b haplotype conferred non-responsiveness to VH315, V lambda 2(315), and Fv315.

Animals↗