Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence on feline cells of class I and class II I-E type major histocompatibility complex (MHC) homologues was demonstrated using cross-reacting monoclonal antibodies (mAb). The feline class I antigen homologues were detected with both immunofluorescent and biochemical techniques, using the anti-human class I mAb W6/32. The class I antigens were detected on in vitro cultured feline fibroblasts and lymphoid cells, but not on fresh lymphoid cells, apparently as a result of the association of bovine beta-2 microglobulin with feline class I heavy chains which generated the determinant(s) recognized by mAb W6/32. Class II I-E-like molecules could be detected with immunofluorescent techniques using the species cross-reactive anti-mouse I-E antibody 40D only when peripheral blood mononuclear cells were activated, for example, with the mitogens staphylococcus enterotoxin A or lipopolysaccharide. The predominant expression of I-A-like molecules by resting class II-positive feline cells could explain some of the functional difference we have seen in comparison with those of most other mammalian species.
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PMID:The detection of conventional class I and class II I-E homologue major histocompatibility complex molecules on feline cells. 317 36

CH31 and CH33 are B cell lymphomas whose growth in vitro is inhibited by anti-Ig reagents, including both polyclonal and monoclonal anti-mu antibodies, and an anti-idiotype antiserum. Antibodies against class I or class II major histocompatibility complex antigens do not affect the growth of these cells. Inhibition is dependent on surface Ig cross-linking and does not require ligand binding to Fc receptors. Interestingly, the inhibition of growth by anti-mu is reversed in CH31 (but not CH33) by E. coli lipopolysaccharide. These lymphomas should provide excellent models to study the mechanisms of growth inhibition mediated by surface Ig cross-linking and the pathways of its reversal.
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PMID:Lymphoma models for B cell activation and tolerance. IV. Growth inhibition by anti-Ig of CH31 and CH33 B lymphoma cells. 349 48

The number of molecules expressed on the B cell membrane is known to influence the level of immune responses. However, a careful study of the changes in numbers of cell surface molecules during B cell differentiation has not been undertaken. We have addressed this question by using an inducible B cell lymphoma, CH12. Scatchard analysis was used to quantitate the levels of expression of surface immunoglobulin, major histocompatibility complex-encoded class I and class II molecules, and Ly-1 molecules on these cells during their differentiation in response to lipopolysaccharide (LPS). We found that the density of most molecules on the initial population of CH12 cells was comparable to their densities on small splenic B cells. Upon culture, we could classify the molecules into two groups based on their change in expression. One group, represented by surface immunoglobulin and class II molecules, decreased (surface immunoglobulin) or did not change (class II) in number after LPS stimulation, but increased during culture in the absence of LPS. The second set, represented by class I and Ly-1 molecules, increased after LPS stimulation, but did not change as a result of culture. Although the characteristic behavior of class I and class II molecules was different, concomitant changes were observed in both class I (K and D) molecules, and in both class II (I-A and I-E) molecules.
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PMID:Quantitation of cell surface molecules on a differentiating, Ly-1+ B cell lymphoma. 349 80

A series of cloned murine B lymphoma cell lines including WEHI-5, WEHI-231, 2PK-3 and L10A/2J have been studied previously for their ability to present soluble protein antigen in a major histocompatibility complex (MHC) restricted fashion. These B cell lines have been shown to be effective accessory cells in the in vitro stimulation of antigen-specific, MHC-restricted, continuous T cell lines; and in the in vitro stimulation of antigen-specific, MHC-restricted T-T hybridoma cell lines. Using 2PK-3 and L10A/2J as examples of this group of B cell lymphomas we demonstrate in this study that these tumor cell lines constitutively release an interleukin-1 (IL-1) like factor activity as determined by the ability of the conditioned medium from these cultures to support the synergistic stimulation of thymocyte proliferation in the presence of concanavalin A (Con A). Conversely, these same constitutive supernatants will not stimulate the proliferation of IL-2 dependent cell lines such as CTLL-2 or HT-2. Stimulation of 2PK-3 and L10A/2J by lipopolysaccharide (LPS) results in the release of increased levels of the IL-1 like factor activity. By contrast, stimulation of the same cloned 2PK-3 and L10A/2J cell lines with the polyclonal activator Staph. aureus results in the release of a soluble factor activity which functionally acts like IL-2 since conditioned medium from S. aureus stimulated 2PK-3 and L10A/2J cultures will support a CTLL proliferation response as well as stimulate thymocyte proliferation. Thus, the same cloned B cell lines can be differentially stimulated to release lymphokine activity with either IL-1 or IL-2 like functional properties.
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PMID:The same cloned murine B lymphoma cell lines can be selectively induced to release either interleukin-1- or interleukin-2-like factor activity. 349 8

Susceptibility to experimental autoimmune thyroiditis (EAT) in the mouse is linked to the I-A subregion of the major histocompatibility complex. EAT can be induced in susceptible strains of mice by immunization with mouse thyroglobulin (MTg) and adjuvant. We have described a cell transfer system wherein spleen cells from EAT-susceptible CBA/J mice primed in vivo with MTg and lipopolysaccharide (LPS) can be activated in vitro with MTg to transfer EAT to naive syngeneic recipients. This cell transfer system was used to elucidate the cellular basis for the I-A restriction in EAT. While the cell active in transferring EAT was Thy 1+ I-A-, depletion of I-A+ cells from the in vitro culture prevented the activation of EAT effector T cells. MTg-pulsed mitomycin C-treated naive syngeneic spleen cells as antigen-presenting cells (APCs) could replace the I-A+ cells in vitro. Allogeneic (Balb/c) APCs were ineffective. Using APCs from several recombinant inbred strains of mice, it was shown that C3H/HEN and B10.A(4R) APCs were effective in activating MTg/LPS-primed CBA/J spleen cells to transfer EAT while B10.A(5R) APCs were ineffective. This maps the H-2 restriction to the K or I-A subregions. Addition of polyclonal anti-Iak or monoclonal anti-I-Ak or anti-L3T4 during in vitro activation inhibited both the generation of EAT effector cells and the proliferative response to MTg. Irrelevant anti-Ia reagents, monoclonal anti-I-Ek, and monoclonal anti-I-Jk were ineffective. Thus the I-A restriction in murine EAT appears to result from an I-A restricted interaction between Ia+ APCs and Ia- EAT effector T cells.
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PMID:The cellular basis for the Ia restriction in murine experimental autoimmune thyroiditis. 349 88

Factor B, the complement alternative pathway serine proteinase, a class III gene product of the major histocompatibility complex, is a major constitutive secretion product of mouse mononuclear phagocytes. This glycoprotein was synthesized and secreted by macrophages as a doublet of Mr 90,000 and 93,000 polypeptides that were immunoprecipitable with antibodies raised to human serum factor B, and that were indistinguishable from plasma factor B by immunoreactivity, peptide mapping, and molecular weight. Macrophage factor B was cleaved and activated to factor Bb- and Ba-like fragments by factor D and cobra venom factor. Some conversion of macrophage factor B to Bb-sized fragments occurred spontaneously in the conditioned culture medium after several hours. Factor B represented approximately 0.5% of newly synthesized protein and 4-6% of the secreted protein of resident peritoneal macrophages and macrophages elicited with thioglycollate broth, pyran copolymer, NaIO4, bacillus Calmette-Guerin, or Corynebacterium parvum. We detected synthesis of factor B immediately upon explanting these macrophages in culture; synthesis continued for several days in culture. The rate of secretion of factor B, as a proportion of total protein secretion in culture, remained constant with time. By radioimmunoassay, factor B antigens accumulated in the 24-h macrophage-conditioned culture medium at 2-10 nM, and was present in cell lysates at 4-8 nmol per 10(6) cells. We detected synthesis of factor B in bone marrow-derived macrophages as early as 5 d of culture. The P388D1 macrophage line synthesized factor B, but mouse L cells did not. In contrast, apolipoprotein E, another secreted protein of macrophages, was secreted by resident and thioglycollate-elicited macrophages but not by freshly harvested pyran copolymer-activated macrophages. Its synthesis was initiated at day 9 in culture of bone marrow-derived macrophages. These data support the classification of factor B as a constitutive biosynthetic and secreted protein of immature and mature macrophages in various states of activation. Production of factor B was modulated by treatment of macrophages in vivo or in culture with bacterial lipopolysaccharide endotoxin, which increased the synthesis, secretion, and accumulation of factor B up to 11-fold.
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PMID:Factor B, the complement alternative pathway serine proteinase, is a major constitutive protein synthesized and secreted by resident and elicited mouse macrophages. 384 38

The monoclonal antibodies (mAb) DA6.147, DA6.164, and HIG.48 against human Ia antigens, but not the W6/32 mAb against human class I major histocompatibility complex antigens or the anti-monocyte OKM1 and 63D3 mAb, stimulated monocytes to secrete interleukin 1 (IL-1). IL-1 was measured by its property of promoting the production of interleukin 2 (IL-2) by phytohemagglutinin-treated LBRM-33 clone 1A5 cells. IL-1 activity induced by anti-Ia antibodies could be detected 24 hr after initiation of the cultures and reached its highest levels at days 3-4 of culture. Concentrations of 1 microgram/ml or higher of the anti-Ia antibodies induced monocytes to secrete significant levels of IL-1 activity. The anti-Ia mAb induced Ia-bearing but not Ia-negative monocytes to secrete IL-1. Both Ia-positive and Ia-negative monocytes produced IL-1 activity under the stimulus of lipopolysaccharide. It is concluded that the DA6.147, DA6.164, and HIG.48 mAb stimulate secretion of IL-1 by interacting Ia antigens on monocytes. The data support the view that besides serving as restricting elements for recognition of foreign antigens by T cells, Ia antigens may also function as transducer elements.
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PMID:Monoclonal antibodies against human Ia antigens stimulate monocytes to secrete interleukin 1. 387 60

We have previously shown that BALB/c anti-DBA/2 T cells can lyse the Moloney virus-induced BALB/c lymphoma YC8. In order to determine whether serologically defined minor histocompatibility antigens (MiHA) cross-reacting with those of DBA/2 tissues are present on YC8, we produced an antiserum directed against non-H-2 antigens by immunizing BALB/c mice with DBA/2 Con A and lipopolysaccharide (LPS)-induced lymphoblasts. In a direct complement-dependent cytotoxicity assay, the antiserum (OR-1) lysed DBA/2 and YC8 but not BALB/c lymphocytes and blasts. No reactions against viral antigens were detected in the antisera as shown by the lack of cytotoxicity on a panel of lymphomas expressing a variety of viral antigens. In addition, OR-1 was able to specifically block a cytotoxic T lymphocyte (CTL), H-2-restricted BALB/c anti-DBA/2 cytotoxic response when bound to DBA/2 or to YC8 target cells. These results indicate that antigens cross-reacting between YC8 lymphoma and DBA/2 tissues are serologically defined MiHA of DBA/2 background and that OR-1 serum can block a CTL reaction by binding to target antigen rather than to major histocompatibility complex products.
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PMID:DBA/2-like minor histocompatibility antigens on a BALB/c lymphoma. A BALB/c anti-DBA/2 serum which lyses the tumor and blocks BALB/c anti-tumor and anti-DBA/2 effectors. 387 2

The mechanism by which soluble anti-IgM inhibits plaque formation by lipopolysaccharide-stimulated B cells was investigated. Since lower amounts of immunoprecipitable mu heavy and kappa light chains were found in cell lysates, this indicated that soluble anti-IgM was inhibiting not only secretion. Subsequently, Northern blot analysis of poly(A+) RNA showed that the steady state levels of mRNA for immunoglobulin heavy and light chain from B cells stimulated with lipopolysaccharide were reduced if the cultures were treated with soluble anti-IgM. The steady-state levels of class I major histocompatibility complex antigen RNA were unaffected by anti-IgM treatment. Addition of supernatants from mouse spleen cells stimulated with concanavalin A at day 2 of culture partially reversed the effect of soluble anti-IgM on immunoglobulin expression.
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PMID:Anti-IgM treatment influences immunoglobulin heavy and light chain mRNA levels in mitogen-stimulated B lymphocytes. 392 32

The receptor specificity of H-2-restricted T lymphoblasts activated against trinitrobenzene sulfonate (TNBS)-coupled spleen cells was examined using an antigen binding assay. A population of Lyt-1+,2-T lymphoblasts acquired syngeneic Ia determinants during 4 days of primary culture with hapten-coupled stimulator cells. Syngeneic Ia was not reexpressed after trypsin treatment of the T cells, but was found after incubation with soluble Ia shed from lipopolysaccharide-activated blasts. Self-Ia binding was specific in that Lyt-1+,2- but not Lyt-1-,2+ cells acquired the antigen, and in that self-Ia bound more effectively than allogeneic Ia material. To determine the relationship of self-Ia binding to the recognition of foreign antigen, the binding of trinitrophenyl (TNP)-coupled plasma membrane vesicles by TNP-specific T cells was studied. TNP-vesicle binding occurred via TNP and H-2(Ia) molecules on the vesicles in that binding was inhibited with antibodies against TNP or H-2(Ia) molecules but not non-major histocompatibility complex (e.g., Ly-6.2) molecules on the vesicles. Complete inhibition of TNP-vesicle binding by an Iak-restricted TNP-specific T-cell line occurred with soluble TNP-lysine, but not an unrelated hapten, N-iodoacetyl-N-(5-sulfonic-1-naphthyl)ethylenediamine (I-AED)-cysteine. Conversely, I-AED-cysteine, but not TNP-lysine, inhibited binding of I-AED-coupled B6 vesicles by B6 anti-I-AED T cells. Significant, but weak inhibition of TNP-vesicle binding by the anti-TNP line was observed with glycoprotein preparations containing partially purified self-Ia molecules. However, inhibition was specific for I-Ak molecules, in that inhibition was lost after removal of I-Ak molecules from the glycoprotein preparation, and very little inhibition occurred with soluble glycoproteins prepared from thymocytes which contained very little Ia material or from LPS blasts of an unrelated H-2 haplotype. These results suggest a recognition model in which TNP and Ia determinants are recognized by neighboring receptor combining sites.
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PMID:Receptor specificity of Ia-restricted T lymphoblasts activated against trinitrobenzene sulfonate-coupled spleen cells: recognition of distinct trinitrophenyl and Ia moieties. 619 19


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