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Biomedical subjects

M B Brenner

Publications and source records attributed to M B Brenner.

134 records · Page 8Linked to original sources
PubMed1984

In vitro T lymphocyte proliferative response to Yersinia enterocolitica in Reiter's syndrome. Lack of response in other HLA-B27 positive individuals.

We assessed the in vitro T lymphocyte tritiated thymidine (3HTdr) incorporation response of Reiter's patients in the United States to a serotype 3 strain of Yersinia enterocolitica. The mean 3HTdr incorporation response to the formalin killed form of this strain was 27,409 +/- 5,488 counts per minute for 14 HLA-B27 positive Reiter's patients compared with 5,414 +/- 3,490 cpm for a control group of 11 HLA-B27 positive normal individuals (P less than 0.0005). This high response in Reiter's patients was observed with the formalin killed form of Y enterocolitica serotype 3, but not with a heat killed form or a rough mutant form derived from the same bacterial strain. Further, Y enterocolitica of a different serotype (serotype 8) which is not associated with reactive arthritis failed to induce the high proliferative response observed with the serotype 3 strain. This response indicates that T lymphocytes from spontaneous Reiter's patients are capable of recognizing and proliferating to determinant(s) on the formalin killed form of Y enterocolitica serotype 3. Since this bacterium is associated with Reiter's syndrome in Europe but not the United States, these data are consistent with the possibility that our patients have previously encountered these or similar determinants through unrecognized infection with other microorganisms.

Antibodies, Bacterial↗
PubMed1984

Antigenic stimulation regulates the level of expression of interleukin 2 receptor on human T cells.

Antigen-specific, interleukin 2 (IL-2)-dependent human T-cell lines and clones were utilized to study the relationship between IL-2 receptor expression and antigenic stimulation. T cells that had not been exposed to antigen for 2 wk or more expressed a stable low level of the IL-2 receptor. After reexposure to antigen, a 10- to 30-fold increase in the level of the IL-2 receptor was rapidly induced, with the peak level of IL-2 receptor expression occurring at 15-30 hr. This peak preceded the peak in cell proliferation [( 3H]thymidine incorporation), which was at 48-72 hr. Within 2-14 days after peak IL-2 receptor expression, it returned to a low base-line level. The transient elevation in IL-2 receptor level was antigen specific because it occurred in response to specific allogeneic stimulator cells but not after exposure to cells expressing irrelevant HLA allotypes. The levels of other cell-surface proteins, including those related to T-cell activation (HLA-DR, T10, 4F2, A-1A5) as well as T3, which has been proposed to be a component of the T-cell receptor complex for antigen, did not change in response to antigen exposure or deprivation. Because IL-2 was maintained at a consistently high level throughout these experiments, the antigen-induced changes in the IL-2 receptor appear to be independent of changes induced by IL-2 itself. Both cloned T cells and mixed populations containing T4 and T8 subsets showed similar IL-2 receptor responsiveness, indicating that this finding is generalizable to most, if not to all, antigen-responsive T cells.

Antibodies, Monoclonal↗
PubMed1984

A study of the specificity of the direct binding between bacteria and HLA antigens.

In the first step of the present study we re-examined the question whether HLA class I molecules isolated from human lymphocytes can bind to intact bacteria. HLA antigens were isolated from the lymphoblastoid cell line HOM-2 and incubated with the bacteria Yersina enterocolitica. Significant binding of antigens to the bacteria was detected whether the antigens were solubilized in the detergent NP 40, reconstituted in liposomes or presented as papain cleaved molecules. Next, we studied the specificity of the binding. We compared the ability of NP 40 solubilized HLA antigens derived from four different cell lines, expressing different HLA-A, -B and -C antigens, to bind to nine different strains of bacteria. Remarkably, few differences were found in that each strain of bacteria bound 10-30% of the HLA antigens derived from any of the four cells lines. Further, after a sample of HLA antigens had been incubated with one strain of bacteria, the unbound HLA antigens would fail to bind to another strain. The conclusions are as follows. First, we have confirmed a previous report that HLA class I antigens could bind to bacteria. Second, binding to bacteria is mediated through the extracellular portion of the HLA molecules which is not affected by papain cleavage. Third, it is the non-polymorphic areas of the HLA antigens which are responsible, because antigens purified from cell lines with different HLA-A, -B and -C allotypes have similar binding ability. Lastly, the binding of bacteria to HLA antigens is a universal phenomenon which does not distinguish one strain of bacteria from another.

Bacteria↗
PubMedDate not supplied

Identification of a putative second T-cell receptor.

Framework monoclonal antibodies have identified a population of human lymphocytes that express the T3 glycoprotein but not the T-cell receptor (TCR) alpha- and beta-subunits. Chemical crosslinking experiments reveal that these lymphocytes express novel T3-associated polypeptides, one of which appears to be the product of the T gamma gene. The other polypeptide may represent a fourth TCR subunit, designated T delta.

Antibodies, Monoclonal↗
PubMedDate not supplied

A functional T3 molecule associated with a novel heterodimer on the surface of immature human thymocytes.

The known T-cell receptors (TCRs) involved in the recognition of antigen and major histocompatibility complex (MHC) molecules are glycoproteins comprised of polymorphic disulphide-linked alpha- and beta-chains. The genes encoding these chains are homologous to immunoglobulin genes and consist of V (variable), J (joining) and C (constant) regions that rearrange during development. TCRs are expressed relatively late in thymocyte development and only in association with an invariant molecular complex of proteins termed T3. Immature thymocytes do not express the TCR-T3 complex but do express messenger RNA encoding a third rearranging T-cell receptor-like gene, termed T gamma. Here we report a clone of normal immature T4-T8- human thymocytes, designated CII, which does not express mature mRNA for T alpha or T beta genes, but does express high levels of T gamma mRNA. This clone also expresses high levels of surface T3, and antibodies to T3 induce immunologically relevant functions in CII cells. Immunoprecipitation of CII surface-labelled proteins with anti-T3 co-precipitates a T3 molecular complex together with two additional and novel peptides of relative molecular mass (Mr), 44,000 (44K) and 62,000 (62K).

Antibodies, Monoclonal↗
PubMedDate not supplied

Two forms of the T-cell receptor gamma protein found on peripheral blood cytotoxic T lymphocytes.

The T-cell receptor (TCR) gamma polypeptide is expressed associated with CD3 (T3) on the surface of normal human peripheral blood lymphocytes. These cells function as non-MHC-restricted cytotoxic T lymphocytes (CTL)and thus may play an important role in host immune defence. The TCR gamma polypeptide occurs as a dimer in at least two molecular forms based on the absence or presence of disulphide linkage. These forms use TCR gamma polypeptides with strikingly different peptide backbone sizes.

Antigens, Differentiation, T-Lymphocyte↗
PubMedDate not supplied

T-cell receptors of human suppressor cells.

Cells which can suppress the immune response to an antigen (TS cells) appear to be essential for regulation of the immune system. But the characterization of the TS lineage has not been extensive and many are sceptical of studies using uncloned or hybrid T-cell lines. The nature of the antigen receptor on these cells is unclear. T cells of the helper or cytotoxic lineages appear to recognize their targets using the T-cell receptor (TCR) alpha beta-CD3 complex. TCR beta-gene rearrangements are also found in some murine and human suppressor cell lines but others have been shown not to rearrange or express the beta-chain or alpha-chain genes. We previously established TS clones derived from lepromatous leprosy patients which carry the CD8 antigen and recognize antigen in the context of the major histocompatibility complex (MHC) class II molecules in vitro. We here report the characterization of additional MHC-restricted TS clones which rearrange TCR beta genes, express messenger RNA for the alpha and beta chains of the TCR and express clonally unique CD3-associated TCR alpha beta structures on their cell surface but do not express the gamma chain of the gamma delta TCR on the cell surface. We conclude that antigen recognition by at least some human CD8+ suppressor cells is likely to be mediated by TCR alpha beta heterodimers.

Antibodies, Monoclonal↗