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R Winchester

Publications and source records attributed to R Winchester.

At least 55 records · Page 3Linked to original sources
PubMed1989

Aspects of the spectrum, prevalence and disease susceptibility determinants of Reiter's syndrome and related disorders associated with HIV infection.

Arthrocutaneous disorders including Reiter's syndrome, psoriasiform rashes, and other forms of chronic arthritis and enthesopathy, such as psoriatic arthritis, occur with an increased prevalence in the setting of HIV infection. Herein we describe the spectrum and prevalence of musculoskeletal and allied skin disorders as they occur in the setting of HIV infection. The role of genetic susceptibility in the development of these disorders is addressed. Based on the frequency of infectious agents capable of triggering reactive arthritis and the presence of HLA-B27 in 71% of these individuals, it is suggested that the disorder strongly resembles Reiter's syndrome as it occurs in the not HIV-infected group. Preliminary evidence indicates an enhanced penetrance for susceptibility among HLA-B27 individuals. In contrast, among HIV-infected patients with psoriasiform lesions there was no statistically significant association (P less than 0.05) between the presence of psoriasiform rash and the HLA alleles Cw6, B7, B17, Bw16, or Bw57 when compared with HIV-infected controls. These findings suggest that among HIV-infected individuals the development of Reiter's syndrome involves an immune recognition event primarily dependent upon HLA-B27 molecules in which an unknown antigen in the context of HLA-B27 is presented to CD8 lineage suppressor/cytotoxic cells. In contrast, the pathogenesis of psoriasiform lesions in HIV patients, despite their similarity to certain lesions in Reiter's syndrome, proceeds by distinct pathways that do not involve events influenced by specific polymorphic class I molecules.

Arthritis, Psoriatic↗
PubMed1989

DNA sequence analysis of the HLA-DRw12 allele.

The complete DNA sequence of a DR beta chain cDNA encoding the DRw12 allele has been determined. The sequence of this DRB1 allele reveals a structural relationship to the group of other DRB1 genes found on DRw52 haplotypes, such as DR3, -w11, -w13, -w14, and -w8. The structural similarities among this group of alleles are particularly evident in the first hypervariable as well as in the 3' untranslated region. The second hypervariable region contains a unique sequence not identified in any other DRB1 allele. The third hypervariable region appears to have arisen by gene conversion events involving two DRB1 chain genes, DR7 and DR1 or DR2/Dw21.

Alleles↗
PubMed1989

Definition of DRw10 by restriction fragment length polymorphism.

To better define the presence of the DRw10 haplotype which has sometimes proved difficult to type by using serologic reagents, Southern blot analysis was performed on seven DRw10 heterozygous individuals with rheumatoid arthritis. Using the restriction enzymes Taq I or BamH I, the restriction fragment length polymorphism (RFLP) pattern for the DRw10 haplotype was clearly distinguishable from that of other DR alleles. Digestion with Taq I revealed a unique DR beta/Taq I 12.20 fragment. A characteristic DR beta/Taq I 4.60 fragment was also present only in DRw10 and DR1 haplotypes. Digestion with the restriction enzyme BamH I revealed a DR beta/BamH I 5.07 fragment also present in DRw10 and DR1 haplotypes, and a DR beta/BamH I 4.30 fragment shared with the DRw52 and DR2 haplotypes but not found in DR1 haplotypes. The pattern was readily distinguished from those given by the haplotypes DR4, 7 and w9. Family studies of five individuals demonstrated appropriate segregation of the restriction fragments. In particular, segregation of DRw10 haplotypes from DR1 haplotypes was clearly shown in a family in which the DRw10 haplotype was associated with rheumatoid arthritis in two individuals. Southern blot analysis proved to be a useful alternative method for identifying the DRw10 allele in certain combinations where this allele has been difficult to define serologically.

Arthritis, Rheumatoid↗
PubMed1989

Acquired congenital heart block. Pattern of maternal antibody response to biochemically defined antigens of the SSA/Ro-SSB/La system in neonatal lupus.

The molecular basis of autoantibody reactivity with components of the SSA/Ro-SSB/La particle exhibited by sera of mothers of infants with severe and permanent manifestations of neonatal lupus (NLE) was investigated using immunoblotting and immunoprecipitation. The characteristics of NLE that were studied included congenital complete heart block (CCHB), second degree heart block, and hepatic fibrosis. Antibodies specific for one or more components of the SSA/Ro-SSB/La particle were found in sera from all 20 mothers of permanently affected infants. However, no antibody specific for a single peptide of this particle was common to all sera. Using tissue extracts from a human cell substrate, 80% of these sera had antibodies to one or more components of the SSA/Ro particle demonstrable by immunoblotting. The predominant antibody response in the NLE group was to the newly recognized 52-kD SSA/Ro peptide component. In contrast, antibodies to the 60-kD SSA/Ro component although present, were the least represented and not significantly increased in frequency among mothers of these infants, compared with a group of 31 mothers with autoimmune diseases such as systemic lupus erythromatosus (SLE) but who had healthy offspring. Antibodies directed to the 48-kD SSB/La antigen were demonstrated in 90% of the NLE mothers often accompanying antibodies against the 52-kD SSA/Ro component. The combination of antibodies to 48- and 52-kD structures was significantly increased in the NLE group, with an odds ratio of 35. The type of cell or tissue substrate was shown to influence detectability of antibodies. The 52-kD SSA/Ro peptide and the 48-kD SSB/La peptide were abundant in cardiac tissues from fetuses aged 18-24 wk, further supporting the possible relevance of these peptides to heart block.

Autoantibodies↗
PubMed1988

Nucleotide sequence of a DRw10 beta chain cDNA clone. Identity of the third D region with that of the DRw53 allele of the beta 2 locus and as the probable site encoding a polymorphic MHC class II epitope.

The nucleotide and inferred amino acid sequence of a DRw10 beta chain was obtained from cDNA clones isolated from a DR1, DRw10 heterozygous cell line. The sequence of this beta chain gene was distinctive, differing from those of all other defined DR types. The DRw10 beta chain gene was shown by transfection experiments to encode a polymorphic epitope recognized by mAb 109d6 that is also encoded by the DRw53 beta 2 chain gene. Comparison of the nucleotide sequence of both genes revealed that their third D regions (amino acids 67 to 73) were identical. This suggested first that the 109d6 epitope could be encoded by residues of this region, and second, that a putative gene conversion event transferred this sequence along with the information encoding the 109d6 epitope from a donor gene such as DRw53 beta 2. The sequence of the DRw10 beta chain gene was observed to be identical to that of clone pII beta 4 derived from the non-DR3 haplotype in the Raji cell line, which was also demonstrated to express the determinant recognized by antibody 109d6, suggesting that the typing of this cell line is HLA-DR3/DRw10. No evidence was found for the existence of a DR beta 2 chain gene product encoded by the DRw10 haplotype. The DRw10 haplotype was of particular interest because it was present along with a DR1 haplotype in the propositus who had rheumatoid arthritis, and was shared by the DR4-positive son of the propositus, who also had rheumatoid arthritis. This raised the possibility that the DRw10 haplotype, and most probably one or more specific conformations encoded by the DR beta chain, are involved in the definition of the disease susceptibility phenotype.

Alleles↗
PubMed1988

Identification of the DRw10 DR beta 1-chain allele as encoding a polymorphic class II major histocompatibility complex epitope otherwise restricted to DR beta 2 molecules of the DRw53 type.

Although the polymorphic human Ia epitope recognized by monoclonal antibody 109d6 typically is expressed by DRw53 beta 2 chains, the epitope was shown to be encoded by distinctive DR beta 1 chains of a DRw10 haplotype in three unrelated DR4-negative individuals with rheumatoid arthritis. No evidence of a DR beta 2 (DR beta 4) chain molecule was found to be encoded by this haplotype. Using two-dimensional gel analysis and partial radioactive N-terminal microsequencing, the DR and DQ products were characterized in the heterozygous members of a family in which the segregation of both varieties of DR beta chains specifying the 109d6 epitope was demonstrated. The expression of the epitope on the DR beta 2 chain, but not on the DR beta 1 chain, was abolished by preventing N-linked glycosylation, although in both molecules the epitope was not altered by neuraminidase digestion. The potential structural bases of the serologic cross reactions of DRw10 are discussed, as are the possible implications of the findings for the definition of susceptibility to rheumatoid arthritis.

Alleles↗
PubMed1988

Surface expression of Gp 165/95, the complement receptor CR3, as a marker of disease activity in systemic Lupus erythematosus.

Complement-derived peptides capable of activating neutrophils appear in plasma during flares of systemic lupus erythematosus (SLE). One possible consequence of such activation is an increased expression of the surface adhesion promoting heterodimer gp165/95 (the complement receptor CR3). The quantity of gp165/95 was measured by indirect immunofluorescence using a monoclonal antibody of the CD11b group. Mol, directed to the alpha chain. Eighty-three percent of 26 patients with SLE expressed gp165/95 on their neutrophil surface to a greater extent than normals. The highest levels of surface gp165/95 were found in patients with the most severe disease, who also had the highest levels of the circulating anaphylatoxin C3a (mean = 560 ng/ml versus 147 ng/ml in controls). There was a negative correlation between expression of gp165/95 and absolute neutrophil count. Five individuals followed serially demonstrated an increase in surface gp165/95 during disease flares which returned to normal with clinical improvement. These data support the hypothesis that the neutrophils of patients with active SLE recruit increased numbers of gp165/95 molecules to their surface in respose to complement activation; these activated neutrophils bearing increased numbers of adhesion promoting gp165/95 may contribute to endothelial injury in SLE.

Antibodies, Monoclonal↗
PubMed1988

HLA-Dw14 and HLA-DR3 haplotypes share a functional determinant recognized by a human alloreactive T-cell clone.

In the process of studying the fine specificity of HLA class II molecules, we identified an alloreactive T-cell clone raised to a HLA-Dw14 homozygous cell line that was specifically stimulated by Dw14+ homozygous typing cells but negatively with cells expressing the HLA-Dw4,-Dw10, -Dw13, and -Dw15 subspecificities of DR4. Of interest, this clone was also equivalently activated by stimulation with all DR3 cells and cell lines tested. Negative responses were obtained using a panel of 87 non-DR3 and non-Dw14 cells, including cell lines of the Tenth Histocompatibility Workshop. A monoclonal antibody inhibition study revealed the relevant stimulating determinant to be on HLA-DR molecules in both Dw14- and DR3-positive cells. A comparison of the DR beta 1-chain-inferred amino acid sequences suggests that formation of a topologically equivalent stimulating determinant would involve the participation of two noncontiguous regions of the third diversity region of DR beta 1. The putative recognition conformation detected by the clone is most probably specified by the presence of a valine at position 86 and a nonnegatively charged residue at positions 70, 71, and 74, since these are the only residues where DR3 and Dw14 are distinguishable from all other HLA-DR types. These findings illustrate that the functional ability of class II molecules is not necessarily either illustrated or predicted by serologic typing or by simple considerations of amino acid sequence.

Amino Acid Sequence↗
PubMed1988

Up-regulation of the iC3b receptor (CR3) is neither necessary nor sufficient to promote neutrophil aggregation.

The iC3b receptor (CR3) is required for neutrophil adhesive functions, including homotypic aggregation. Because stimuli that enhance neutrophil adhesion also induce up-regulation of surface CR3, it is widely held that these two responses are causally related. We have dissociated CR3 display (immunofluorescence) from CR3 function (aggregation). Neutrophils isolated at 4 degrees C and rewarmed to 37 degrees C up-regulated surface CR3 twofold, but did not aggregate. The kinetics of FMLP-induced CR3 up-regulation were discordant with those of aggregation. In the absence of extracellular divalent cations, CR3 expression increased twofold after exposure to FMLP, but neutrophils did not aggregate. FMLP elicited 3.5-fold more aggregation than the ionophore A23187, yet less than one-half as much CR3 up-regulation. 3 mM sodium salicylate inhibited aggregation 55 +/- 4%, but had no effect on CR3 up-regulation. Conversely, 1 mM tetracaine completely inhibited CR3 up-regulation, while significantly enhancing aggregation. Neutroplasts expressed CR3, but did not up-regulate the receptor; in contrast, FMLP induced CR3-dependent aggregation of neutroplasts. We conclude that, although constitutive surface CR3 is required for neutrophil aggregation, the up-regulation of CR3 is neither necessary nor sufficient to promote cell-cell adhesion.

Antibodies, Monoclonal↗
PubMed1988

Implications from the occurrence of Reiter's syndrome and related disorders in association with advanced HIV infection.

Information bearing on the prevalence and character of Reiter's syndrome and allied disorders as they occur in a setting of HIV infection was reviewed. Based on the frequency of infections by organisms capable of inducing reactive arthritis and the presence of HLA-B27 in 71% of the individuals, it was concluded that the disorder strongly resembled Reiter's syndrome occurring in the non-HIV infected group. Preliminary evidence suggested an enhanced penetrance of susceptibility among HLA-B27 individuals. In view of the preservation of CD8 lineage T cells and functional loss of CD4 lineage T cells in HIV-infected patients, it was suggested that a specific immune recognition event is at the center of the pathogenesis of this syndrome which involves preservation of an unknown antigen in the context of HLA-B27 to CD8 lineage suppressor/cytotoxic T cells.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Hypotheses on the molecular basis of susceptibility to rheumatoid arthritis.

An interpretive summary of recent immunologic and molecular biologic data concerning the molecular basis of susceptibility of rheumatoid arthritis will be presented. The central point of view is taken that the MHC class II molecules encoding disease susceptibility function in a specific immune recognition event. This could involve an antigen "X" that currently eludes characterization or be directed to polymorphic determinants on the MHC molecule itself. The problem of understanding the meaning of the association of susceptibility to rheumatoid arthritis with diverse MHC alleles such as DR4 (Dw4 and Dw14) and DR1 is approached by detailed biochemical analysis that led to the identification of common stretches of amino acid sequence, presumably encoding conformationally equivalent structures. The sequence shared by the otherwise unrelated DR1 and DR4 haplotypes from residue 67 in the DR a chain that appears to confer susceptibility is Leu-X-X-Gln-Arg/Lys. Non-classic MHC polymorphisms related to disease susceptibility but not associated with particular alleles such as identified by Ab109d6 prove especially valuable in suggesting new directions for attempting to understand the significance of these associations. Consideration is given to the possibility that a family of either slightly different or identical conformations encoded in either cis or trans cumulatively confer the liability to develop rheumatoid arthritis. This implies a highly non-classic mode of inheritance. It seems reasonable to consider the pathogenesis of rheumatoid arthritis as evolving from a typical immune response based on a simple immune recognition event directed to a single antigen.

Antigens, Differentiation↗
PubMed1988

Diversity in inhibitory effects of IFN-gamma and IFN-alpha A on the induced DNA synthesis of a hairy cell leukemia B lymphocyte clone reflects the nature of the activating ligand.

A hairy cell leukemia population was used as a clonal model for studying the direct immunomodulatory effects of recombinant interferon-alpha A (rIFN-alpha A) and rIFN-gamma on human B-cell proliferation. The leukemic cell population KON was notably quiescent when incubated in medium alone but was induced to significant in vitro DNA synthesis when cultured with any of four activators of human B cells: anti-IgM antibody, Staphylococcus aureus cells (SAC), phorbol myristate acetate (PMA), or B-cell growth factor (BCGF). While both rIFN-gamma and rIFN-alpha A exhibited suppressive effects on these responses, their inhibitory patterns were distinct and reciprocal. Thus, rIFN-gamma exclusively suppressed anti-IgM-and SAC-induced leukemic DNA synthesis, and rIFN-alpha A significantly suppressed only PMA- and BCGF-induced DNA synthesis. The effects of the rIFN preparations were ablated in the presence of IFN type-specific monoclonal antibodies. Kinetic analyses and pulsing studies revealed that inhibition was most notable when cells were exposed concomitantly to IFN and the activating ligand. That the diverse effects of IFN-gamma and IFN-alpha A are manifested on a single B-cell clone was confirmed by Southern blot analysis of restriction enzyme-digested KON cell DNA with a JH-specific probe. These studies suggest that the therapeutic potential of the two types of IFN may be influenced by the nature of the extracellular ligands in the leukemic mileau that promote leukemic clonal expansion.

Antigen-Antibody Reactions↗
PubMed1988

Complete congenital heart block: risk of occurrence and therapeutic approach to prevention.

A retrospective literature review revealed that in 41% of cases of complete congenital heart block (CCHB) there was at least one other affected sibling, emphasizing the considerable risk of carrying a second affected fetus with CCHB. Therefore an aggressive approach was taken to prevent CCHB in a fetus with a high risk for the condition as defined by (1) presence of DR3 and high titers of antibodies to SSA(Ro) and SSB(La) in the mother (2) previous history of CCHB in a sibling. In a feasibility study, thrice weekly plasmapheresis was initiated in the 19th week of gestation to remove antibodies from the maternal circulation in advance of major placental transport to the developing fetus. Prednisone was also administered to decrease antibody synthesis. The concentration of total maternal IgG and antibodies to SSA(Ro) and SSB(La) were decreased by greater than 60% during the course of therapy. Planned delivery of a healthy baby was done at 36 weeks.

Adult↗
PubMed1987

Analysis of the domain specificity of various murine anti-human IgM monoclonal antibodies differing in human B lymphocyte signaling activity.

The domain binding specificity of 19 murine anti-human IgM monoclonal antibodies (MoAbs) that have shown considerable heterogeneity in the transduction of stimulatory and inhibitory signals to B lymphocytes was evaluated by competition radioimmunoassays. Through the use of: (i) enzymatic fragments of IgM which each encompass more than a single CH domain, i.e. Fc5 mu and F(ab')2 mu, (ii) isolated single domains, C mu 2, C mu 3, and C mu 4, and (iii) mu heavy chain disease proteins, nine anti-IgM MoAbs were found to have C mu 1 domain specificity, five to have C mu 2 specificity, and five others to have C mu 4 specificity. Ineffective binding to isolated mu chain demonstrated that C mu 1-specific MoAbs were directed to epitopes which require light chain for expression. The lack of binding of the C mu 4-specific MoAbs to CNBr cleavage fragments of Fc5 mu suggest that the determinants recognized by these MoAbs may also be conformational in nature. Cross-inhibition analyses were used to determine the number of unique epitopes recognized by the anti-IgM MoAbs. Results from these experiments showed that: (i) eight of the nine MoAbs specific for C mu 1 likely bind to a single epitope, or very proximate epitopes, (ii) the five C mu 2-specific MoAbs recognize at least three distinct epitopes, and (iii) the five C mu 4-specific MoAbs each recognize a separate determinant. A comparison of the known B cell activating properties of these MoAbs with their specificity for the various segments of the IgM molecule indicate that mitogenicity cannot be attributed to selective binding to any one domain.

Animals↗
PubMed1987

Monoclonal antibody 1a3 recognizes a monomorphic epitope unique to DQ molecules.

Monoclonal antibody 1a3 reacts with a unique monomorphic epitope present only on DQ molecules as determined by immunoprecipitation, two-dimensional gel analysis and partial N-terminal amino acid sequencing. This monomorphic epitope is found on DQ molecules of all homozygous B lymphoblastoid cell lines tested, including those that type as either DQw1, DQw2, DQw3, or DQ "blank." Analysis of the predicted secondary structure of class II molecules indicates that the regions most likely to constitute an antigenic determinant are variable in DQ molecules, possibly accounting for the rarity of antibodies to monomorphic DQ epitopes.

Antibodies, Monoclonal↗
PubMed1987

Molecular characterization by high-resolution isoelectric focusing of the products encoded by the class II region loci of the major histocompatibility complex in humans. I. DR and DQ gene variants.

We describe a new approach to the analysis of the structural polymorphism of the DR beta, DQ alpha, and DQ beta polypeptide chains of human histocompatibility class II antigens. In comparison to conventional two-dimensional gel studies, this method provides sharper definition of the protein bands and side-by-side comparisons within the same gel, thereby permitting the detection of minor differences in the isoelectric points of the protein chains. Using this methodology we have analyzed the IEF polymorphism and the variability in the number of the DR beta chains encoded by different DR haplotypes. Twenty DR beta chain variants, which include the products of no less than two separate DR beta loci, have been thus far identified. Alleles at one of these loci are assumed to code for DR beta chains carrying the DR alloespecificities DR1, DR2, DR3, DR4, DR5, DRw6, DR7, and DR8. Alleles at a second DR beta locus encode DR beta chains that may be shared by serologically DR-different haplotypes and carry supertypic serologic specificities (i.e., DRw52 and DRw53). We also demonstrate here that the structural polymorphisms of the DQ alpha and DQ beta chains are more extensive than previously thought, report the characterization of 14 DQ beta variants, and define their relationship to the previously described DQw serologic specificities. In addition, we describe the class II haplotype associations observed for the different DR and DQ variants characterized.

Alleles↗