Are tissues a patch quilt of ectopic gene expression?
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Animals↗
Biomedical subjects
B Pernis
Publications and source records attributed to B Pernis.
Binding of labelled influenza matrix peptide to HLA DR in living B lymphoid cells.
T cells recognize protein antigens as fragments (peptides) held in a defined binding site of class I or class II major histocompatibility (MHC) molecules. The formation of complexes between various immunologically active peptides and different MHC molecules has been demonstrated directly in binding studies between the peptides and solubilized, purified molecules of class II MHC. Studies with intact cells, living or fixed, have not directly demonstrated the binding of the peptides to MHC molecules on antigen-presenting cells, but the formation of such complexes has been shown indirectly through the capacity of antigen-presenting cells to stimulate specific T cells. Here we report evidence that supports directly the binding of radiolabelled influenza matrix peptide 17-29 to products of the human class II MHC locus HLA-DR, on living homozygous B-cell lines, and we show that the kinetics of such binding is much faster with living cells than with fixed cells. Furthermore, whereas the peptide reacts with HLA-DR molecules of all alleles, it binds preferentially to DR1, the restricting element in antigen presentation.
Amino Acid Sequence↗
Role of early region 3 (E3) in pathogenesis of adenovirus disease.
The cotton rat Sigmodon hispidus has provided an animal model of adenovirus pneumonia that permits investigation of the viral gene products required to produce the disease and the molecular mechanisms effecting the damage. This study was carried out to test the hypothesis that early region 3 (E3) of the adenovirus genome plays a critical role in pathogenesis of the virus's disease process even though none of its gene products are essential for its replication. Mutants whose E3 region is largely deleted (i.e., H2dl801 and H5dl327) replicated like wild-type virus in the cotton rats' lungs, but the lymphocyte and macrophage/monocyte inflammatory response was markedly increased. Viruses containing mutations that ablated production of the 19-kDa glycoprotein had the same effect as H2dl801 and H5dl327. However, mutants with deletions in the other E3 open reading frames, some of which encode known proteins, did not differ from wild-type virus in their pathogenic properties. The 19-kDa glycoprotein markedly reduces expression of the class I major histocompatibility complex antigens on the surface of infected cells. A complete correlation was found between those mutants that had increased pathogenic effects and those that lost the ability to reduce transport of the class I major histocompatibility complex antigens to surface of infected cells (i.e., all mutants unable to express the 19-kDa glycoprotein). H5sub304, which has a deletion between 83.2 and 85.1 map units in the E3B region and expresses the 19-kDa glycoprotein, did not increase the extent of pneumonia but qualitatively changed the inflammatory response in that increased numbers of polymorphonuclear leukocytes accumulated, often in small foci.
Adenoviruses, Human↗
Seronegative rheumatoid arthritis, rheumatoid factor cross reactive idiotype expression, and hidden rheumatoid factors.
The major rheumatoid factor cross reactive idiotype (RCRI), defined by prototypic monoclonal rheumatoid factors (RFs), is expressed as a dominant idiotype by pokeweed mitogen induced plasma cells obtained from seropositive (RF+) patients with rheumatoid arthritis (RA). Some patients who meet clinical diagnostic criteria for RA set by the American Rheumatism Association fail to express RFs at any time during their clinical course. To determine if seronegative (RF-) patients with RA, so designated by the latex fixation, Rose-Waaler classic binding assays, or a RF enzyme linked immunosorbent assay (ELISA), express the RCRI in the absence of detectable RFs we examined pokeweed mitogen plasma cells from these patients by indirect immunofluorescence. In addition, we used an inhibition ELISA to detect RCRI bearing molecules in the sera of RF- patients with RA. Five of 10 RF- patients with RA had a high prevalence of RCRI+ plasma cells (16-49% of total pokeweed mitogen plasma cells in culture). Six of 20 RF- patients with RA had high serum concentrations of molecules marked by the RCRI, equivalent to 21-110 micrograms/ml of RCRI+ reference monoclonal IgM RF. Four of five patients who expressed the RCRI in high prevalence in pokeweed mitogen plasma cells, also demonstrated high concentrations of RCRI in their sera detected by inhibition ELISA. There was significant concordance of RCRI expression determined by the two different assays. Four RF- patients with RA who expressed RCRI in their whole sera had hidden RFs detected in their 19S and, in one case, 7S serum fraction. Detection of RF related molecules in whole sera by the expression of RCRI in RF- patients with RA identifies a subgroup of RF- patients with RA who possess hidden RFs. Some RF- patients with RA can express the major RCRI in pokeweed mitogen plasma cells and in their sera and therefore are related to patients with prototypic Waldenstrom's macroglobulinaemia, who produce RCRI+ 19S IgM monoclonal RFs.
Adult↗
The major rheumatoid factor cross-reactive idiotype in rheumatic disease.
The major rheumatoid factor cross-reactive idiotype (RCRI), a tertiary structure formed by both light and heavy chains, is found on 60% of all monoclonal IgM kappa RFs. To determine if the RCRI is expressed in patients with rheumatic disease, we used polyclonal rabbit anti-idiotypic antibodies to detect RCRI in sera and in pokeweed mitogen cultures of blood mononuclear cells (PBM) from patients with rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). We detected increased expression of RCRI+, plasma cells in PWM cultures, and in sera from these patients. We have determined that some 7S IgM molecules from RF+RA patients are RCRI+, and can bind IgG in a sensitive RF ELISA. We have also observed that the CD5+ B cell subset, which is responsible for autoantibody production, generates RCRI+ antibodies. We review these data and discuss the relationship of the idiotypic network of interacting antibodies with rheumatic disease.
Animals↗
Cell biology of antigen presentation by B cells.
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Animals↗
New differentiation antigens associated with the growth and maturation of B lymphocytes.
Monoclonal antibodies (mAb) NDA3 and NDA4 were generated by hyperimmunizing mice with an alloreactive human T cell clone and fusing the splenocytes with the NS1 myeloma. Immunofluorescence studies indicated that these mAb react with activated, but not with resting T and B lymphocytes or with other types of cells. Immunoprecipitation studies with 125-I-labeled extracts from T and B cell lines demonstrated that the m.w. of the antigen recognized by mAb NDA3 is 36,000 and that of NDA4 is 46,000. Studies on the effect of mAb NDA3 and NDA4 on Epstein Barr Virus-transformed lymphoblastoid B cell lines (LBCL) demonstrated that these antibodies stimulate B cell proliferation and Ig synthesis. The level of expression of NDA3 and NDA4 on the membrane of LBCL is significantly augmented when cells are grown in the presence of recombinant human interferon-beta and gamma and is decreased in the presence of 12-O-tetradecanoyl-phorbol-13-acetate. These observations, in conjunction with the stimulatory effect of mAb NDA3 and NDA4 on the growth and differentiation of LBCL, suggest that these new differentiation antigens, NDA3 and NDA4, may serve as growth factor receptors.
Animals↗
Cellular expression of rheumatoid factor cross-reactive idiotype in patients with seropositive and seronegative rheumatoid arthritis.
A study has been made of the presence of the major rheumatoid Factor cross-reacting idiotype (RCRI) in the serum of patients with seropositive and seronegative rheumatoid arthritis as well as in the cytoplasm of plasmacells induced by cultivation of peripheral blood leucocytes (PBL) from the same RA patients and from normal humans. The PBL were stimulated in vitro with two different B cell mitogens, namely pokeweed mitogen (PWM) or Staph Auerus Cowan strain I (SAC). The RCRI was detected in the serum of seropositive RA patients and in the serum of four out of twenty seronegative RA patients. In these four, however, the seronegative condition was only apparent, since all four had hidden rheumatoid factors that could be shown after dissociation from IgG. The expression of the RCRI in the cytoplasm of PWM-stimulated PBL from seronegative RA patients was concordant with the expression in the serum. Thus the majority of truly seronegative RA patients also appear not to express the RCRI neither in the serum nor in the cytoplasm of plasmacells induced by PWM stimulation of PBL. An unexpected finding was the detection of the RCRI in plasmacells obtained by SAC stimulation of PBL from normal individuals. Up to 40% of RCRI-positive plasmacells were seen in many of these cultures, as opposed to an average of 2% in cultures stimulated with PWM from PBL of the same individuals. High percentages of RCRI-positive plasma-cells have previously been detected by us in PWM cultures only if these were from PBL from RA patients. Our working hypothesis is that PWM is a non-selective stimulator of B cells and that RCRI + precursors are in high frequency in RA patients, whereas SAC selectively stimulates these precursors even in normal PBL populations, where their frequency is not abnormally high.
Adult↗
Monomeric (7S) IgM found in the serum of rheumatoid arthritis patients share idiotypes with pentameric (19S) monoclonal rheumatoid factors.
Serum from some seropositive (RF+) rheumatoid arthritis (RA) patients contains relatively high concentrations of monomeric (7S) IgM molecules. Seven S IgM molecules fail to bind the Fc portion of IgG, unlike 19S IgM RFs that bind aggregated IgG in classical RF assays. Some pentameric IgM RFs are marked by crossreactive idiotypes (RCRI) defined by prototypic monoclonal RFs. In previous studies, we observed that a proportion of pokeweed mitogen (PWM) induced plasma cells from RA patients' blood lymphocytes express the major RCRI as assayed by indirect immunofluorescence with polyclonal anti-RCRI antibodies. In this study, 7S IgM obtained from three different RF+ RA patients inhibits specific anti-RCRI intracytoplasmic staining of PWM induced RF+ RA-derived plasma cells. These 7S molecules also block polyclonal anti-RCRI antibodies from reacting with red blood cells bearing 7S IgM molecules from RF+ patients with RA or Waldenstrom's macroglobulinemia. We conclude that some 7S IgM molecules in the serum of RF+ RA patients are marked by the major RCRI idiotype and are related to 19S monoclonal and polyclonal RFs.
Adult↗
Intracellular accumulation of T-cell receptor complex molecules in a human T-cell line.
This work was aimed at understanding the mechanisms of T-lymphocyte function by studying the cellular distribution and traffic of molecules of the T-cell receptor complex. The accumulation of specific molecules in intracytoplasmic vesicles is related to the activation of T lymphocytes. Some of these molecules include acid hydrolases, the transferrin receptor, and class I antigens of the major histocompatibility complex. Molecules of the T-cell receptor complex have now also been found in intracytoplasmic vesicles in a human T-cell line derived from a lymphoblastic leukemia. Such vesicles were tightly associated with the cytoplasmic microtubule network. One functional aspect of this association is a cellular pathway by which vesicles traveling to and from the cell surface converge in an area of the cells that is rich in processing enzymes.
Antibodies, Monoclonal↗
A new HLA-linked T cell membrane molecule, related to the beta chain of the clonotypic receptor, is associated with T3.
The 38 kD molecule is noncovalently associated with beta 2 microglobulin (beta 2m)-free HLA heavy chain-like molecule, and thus forms a second heterodimer distinct from the clonotypic alpha/beta T cell receptor expressed by the same clone of leukemia cells. This second heterodimer (38 kD/HLA) is variably expressed and appears to be associated with the T3 molecule. We suggest, therefore, that it has a functional role in T cell activation.
Antibodies, Monoclonal↗
Dissection of the human antigammaglobulin idiotype system with monoclonal antibodies.
Murine monoclonal antibodies (MoAb) were prepared by immunizing mice with human monoclonal rheumatoid factors from patients with mixed cryoglobulinaemia. Indirect solid phase radioimmunoassay and haemagglutination inhibition were used to screen the MoAb. Reactivity patterns of MoAb were determined using (a) polyclonal and monoclonal IgM proteins, (b) monoclonal IgM proteins from patients with neuropathy, (c) monoclonal and polyclonal IgM antigammaglobulins, and (d) various isolated VkIIIb-positive immunoglobulins. Several patterns were obtained: MoAb reacting with private idiotypic determinants, with VkIIIb-related determinants, and with cross-reactive idiotypes (CRI). Two MoAb of the second type reacted with VkIIIb-positive immunoglobulins and light chains regardless of their antigenic activity. Another MoAb reacted with VkIII light chains only when in association with mu heavy chains. MoAb of the third type defined distinct CRI systems. One of these was restricted to antigammaglobulins and another also involved neuropathy-associated monoclonal IgM proteins. All MoAb clearly reacted with a minor population of normal polyclonal IgM, except for the MoAb detecting private idiotypic determinants. Studies using inhibition of binding by enzyme-linked immunosorbent assay showed that polyclonal IgM antigammaglobulins may carry a CRI determinant detected by one of the MoAb. This CRI system, defined by the MoAb Glo 86.3, was similar to but not identical with the previously described Wa CRI, which is widely prevalent among IgM antigammaglobulins of rheumatoid arthritis.
Animals↗
Recycling class I MHC antigens: dynamics of internalization, acidification, and ligand-degradation in murine T lymphoblasts.
We have previously shown that activated T lymphocytes spontaneously internalize their own surface class I MHC antigens and that this phenomenon is specific for these cells since it does not occur in B lymphocytes even after activation. The present work was aimed at defining the quantitative aspects of this phenomenon and, in particular, at the elucidation of the route of the internalized class I MHC antigens. We intended to determine if the internalized molecules are delivered to the lysosomal compartment and digested there or if instead they are brought back to the plasma membrane in a recycling pathway similar to that described for various cell surface proteins known to be engaged in the process of receptor-mediated endocytosis. We have devised a flow cytometric assay based on the use of fluorochrome-labeled monoclonal anti-H-2K antibodies to measure the kinetics of H-2K internalization. Comparison of the time necessary for the internalization of one-half of the surface H-2K molecules in activated T lymphocytes, which is approximately 1 hour, with the half-life of these molecules on the same cells, which is 14 hours, clearly indicates that the internalized molecules are not degraded but are instead recycled. The recycling takes place in an endosomal compartment with an average pH of about 5.6. The monoclonal anti-H-2K antibody used in these studies was not eluted from the H-2K molecules at this pH and is recycled along with them. On the other hand, protein A bound to the Fc of the anti-H-2K antibody was eluted at the low pH of the endosomes, delivered to lysosomes, and digested. We have therefore defined a novel phenomenon, namely the recycling of class I MHC antigens, which occurs selectively in T lymphocytes. The features of this phenomenon are similar to the recycling of surface receptors which mediate the endocytosis of a variety of extracellular ligands in different cells. However, no physiological extracellular ligand is known for class I MHC antigens. It is a reasonable speculation that upon activation T lymphocytes recycle their own surface class I MHC antigens as part of the complex machinery whereby these lymphocytes recognize and respond to non-self moieties on the plasma membranes of presentor or target cells.
Animals↗
IgD-induced enhancement of the immune response.
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Animals↗
Anti-immunoglobulin stimulation of human B lymphocytes is inhibited by anti-class II major histocompatibility complex antibodies.
The effect of murine monoclonal antibodies binding monomorphic epitopes of Class II, HLA-DR molecules on responding human B lymphocytes stimulated by anti-immunoglobulin M (IgM) antibodies was studied. Goat F(ab')2 anti-human IgM coupled to Sepharose beads (insoluble), or in solution, was added to macrophage-depleted B cells in culture with, or without, anti-human HLA-DR monoclonal antibodies. The addition of monoclonal anti-HLA-DR antibodies to anti-human IgM-stimulated B lymphocytes inhibited this T-independent B-cell proliferation by 82-94%. The role of Class II, HLA-DR molecules on B cells may therefore exceed that of antigen presentation alone, to include responding B-cell activation induced by anti-immunoglobulin.
Antibodies, Anti-Idiotypic↗
A one and a half receptor model for MHC-restricted antigen recognition by T lymphocytes.
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Animals↗
Studies on human low serum IgD phenotype and Gm markers.
The human "low serum IgD phenotype" was studied by simultaneous Gm typing and IgD immunoassay of several populations. An association between Gm (f+b+) haplotype and low human IgD was confirmed and extended to the "low serum IgD phenotype"--as defined from population distribution and genetic studies by Dunnette et al. 1978. Further, it was shown that Black American sera determined by Gm haplotype, had a similar percentage of "low serum IgD phenotype" samples (16%) although they lacked the "associated" Gm(f+b+) haplotype of White American samples. Sardinian sera showed a low incidence of the "low serum IgD phenotype" which was not correlated with Gm haplotype distribution. Familial aggregation of the "low serum IgD phenotype" was observed. No association was found between "low serum IgD phenotype" and serum IgE values. Age related abiotrophy of IgD could not be attributed to selective survival of "low serum IgD phenotype" persons.
Adult↗
Antibodies against monomorphic determinants of the alpha chain of class I human leukocyte antigens inhibit the reaction of human lymphocytes to mitogen and tetanus toxoid.
Monoclonal antibodies directed against the alpha chain of Class I Major Histocompatibility Complex (MHC) antigens inhibit the reactivity of human T lymphocytes to mitogen or antigen. In contrast, monoclonal antibodies to beta 2 microglobulin do not suppress human T cell proliferation to these same stimuli. As antigen presentation by accessory cells involves Class II and not Class I MHC antigens, the inhibition of human T cell proliferation in response to mitogen or antigen may occur at the level of the responder cell. The differential effect seen between monoclonal antibodies directed against the alpha chain of Class I MHC framework determinants and antibodies reactive with the polymorphic determinants suggests functionally separate components of the Class I MHC molecules.
Antibodies, Monoclonal↗