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H O McDevitt

Publications and source records attributed to H O McDevitt.

At least 109 records · Page 6Linked to original sources
PubMed1988

Limited heterogeneity of T cell receptors from lymphocytes mediating autoimmune encephalomyelitis allows specific immune intervention.

Experimental allergic encephalomyelitis (EAE) is an induced autoimmune disease mediated by CD4+ T lymphocytes. Analysis of T cell receptors of myelin basic protein-specific encephalitogenic T cell clones derived from six different PL/J (H-2u) or (PL/J x SJL) F1 (H-2uxs) mice revealed a limited heterogeneity in primary structure. In vivo, the majority of T lymphocytes recognize the N-terminal MBP-nonapeptide in association with I-Au and utilize the V beta 8 gene element. cDNA-sequencing showed that all T cell receptors from a panel of such T cell clones, grown in vitro, share the same V alpha gene segment. Despite heterogeneity in the D-J regions, the clones unexpectedly display a striking similarity in fine specificity. Based on these results, prevention and reversal of autoimmune disease with V beta 8-specific monoclonal antibodies was achieved.

Amino Acid Sequence↗
PubMed1988

Predominant expression of a T cell receptor V beta gene subfamily in autoimmune encephalomyelitis.

TCR beta chain gene expression of individual T cell clones that share the same MHC class II restriction and similar fine specificity for the encephalitogenic NH2 terminus of the autoantigen myelin basic protein (MBP) has been examined. TCR V beta expression was examined by FACS analysis with mAbs specific for the V beta 8 subfamily of TCR beta chain genes. 14 of 18 (78%) NH2-terminal MBP-specific clones examined express a member of the TCR V beta 8 subfamily. Southern analysis was used to identify which member(s) of the TCR V beta 8 subfamily is expressed by these clones. Each of four clones examined uses V beta 8.2, though two different V beta 8.2-J beta 2 combinations were identified. Our findings indicate that there is restricted TCR V beta usage in the autoimmune T cell response to the dominant encephalitogenic NH2-terminal epitope of the MBP. The use of an mAb to the antigen-specific TCR in the prevention of T cell-mediated autoimmune disease has been investigated. Our results demonstrate that in vivo administration of a TCR V beta 8-specific mAb prevents induction of autoimmune encephalomyelitis.

Animals↗
PubMed1988

A newly characterized HLA DQ beta allele associated with pemphigus vulgaris.

The inheritance of particular alleles of major histocompatibility complex class II genes increases the risk for various human autoimmune diseases; however, only a small percentage of individuals having an allele associated with susceptibility develop disease. The identification of allelic variants more precisely correlated with disease susceptibility would greatly facilitate clinical screening and diagnosis. Oligonucleotide-primed gene amplification in vitro was used to determine the nucleotide sequence of a class II variant found almost exclusively in patients with the autoimmune skin disease pemphigus vulgaris. In addition to clinical implications, the disease-restricted distribution of this variant should provide insight into the molecular mechanisms underlying associations between diseases and HLA-class II genes.

Alleles↗
PubMed1988

Tumour necrosis factor-alpha in murine autoimmune 'lupus' nephritis.

The (NZB x NZW)F1 hybrid mouse develops a severe autoimmune disease similar to systemic lupus erythematosus in humans. Both the human and murine form of the disease show strong associations with alleles of the major histocompatibility complex (MHC) gene products. The severe form of the disease found in F1 mice is due, in part, to dominant NZW gene(s) mapping with the H-2 complex (the murine MHC). Here we present evidence that the tumour necrosis factor (TNF-alpha) gene, which is located within the H-2 complex (the murine major histocompatibility complex), could be involved in the pathogenesis of lupus nephritis in F1 mice. Thus, a restriction fragment length polymorphism in the TNF-alpha gene correlates with the reduced levels of TNF-alpha produced by NZW mice. Furthermore, replacement therapy with recombinant TNF-alpha induces a significant delay in the development of the nephritis.

Animals↗
PubMed1988

Aspartic acid at position 57 of the HLA-DQ beta chain protects against type I diabetes: a family study.

One hundred seventy-two members from 27 randomly selected multiple case Caucasian families of patients with insulin-dependent diabetes mellitus (IDDM) were studied at the DNA level to ascertain the reliability of codon 57 of the HLA-DQ beta-chain gene as a disease protection/susceptibility marker. The analysis was carried out by polymerase chain reaction amplification of DNA encoding the first domain of the DQ beta chain and by dot blot analysis of the amplified material with allele-specific oligonucleotide probes. One hundred twenty-three randomly selected healthy Caucasian donors were also tested. The results demonstrated that haplotypes carrying an aspartic acid in position 57 (Asp-57) of their DQ beta chain were significantly increased in frequency among nondiabetic haplotypes (23/38), while non-Asp-57 haplotypes were significantly increased in frequency among diabetic haplotypes (65/69). Ninety-six percent of the diabetic probands in our study were homozygous non-Asp/non-Asp as compared to 19.5% of healthy unrelated controls. This conferred a relative risk of 107 (chi 2 = 54.97; P = 0.00003) for non-Asp-57 homozygous individuals. Even though the inheritance and genetic features of IDDM are complex and are not necessarily fully explained by DQ beta chain polymorphism, this approach is much more sensitive than HLA serolog in assessing risk for IDDM.

Aspartic Acid↗
PubMed1988

Involvement of distinct murine T-cell receptors in the autoimmune encephalitogenic response to nested epitopes of myelin basic protein.

The peptide p89-101 (Val-His-Phe-Phe-Lys-Asn-Ile-Val-Thr-Pro-Arg-Thr-Pro) of myelin basic protein is encephalitogenic in mice expressing H-2q and H-2s antigens. Six of 13 encephalitogen-specific T-cell clones were shown to express the variable beta-chain (V beta) 17a gene product (KJ23a+), whereas seven clones were KJ23a-. Both KJ23a+ and KJ23a- subpopulations were encephalitogenic in SJL/J mice when adoptively transferred. Depletion of KJ23a+ cells in vivo with the administration of the antibody KJ23a suppresses experimental allergic encephalomyelitis induced with KJ23a+ T-cell lines. However, experimental allergic encephalomyelitis induced with either (i) encephalitogenic peptide p89-101, (ii) intact myelin basic protein, or (iii) KJ23a- T cells reactive to p89-101 cannot be prevented with monoclonal antibody KJ23a. These data indicate that in spite of the V beta 17a gene expression in a relatively large proportion of p89-101-specific T cells, such V beta gene use is not essential for the induction of experimental allergic encephalomyelitis in SJL/J mice. These results contrast with the predominance of V beta gene use (V beta 8.2) in T cells reactive to the encephalitogenic fragment (pR1-11) in PL/J mice. One reason for this lack of dominant use of a particular T-cell receptor V beta gene family in the autoimmune response to myelin basic protein in SJL/J mice stems from the observation that two encephalitogenic epitopes exist in p89-101. KJ23a- T cells are stimulated by the deleted peptide p89-100, whereas KJ23a+ T cells are not. Thus, in the response to an encephalitogenic fragment of myelin basic protein containing two nested epitopes, at least two distinct T-cell receptor V beta genes are expressed. These distinct T-cell subpopulations can each trigger experimental allergic encephalomyelitis. These findings have implications for therapy of autoimmune disease with antibodies to the T-cell receptor gene products.

Animals↗
PubMed1987

In vivo treatment of (NZB X NZW)F1 lupus-like nephritis with monoclonal antibody to gamma interferon.

The (NZB X NZW)F1 mouse is recognized as an important animal model of the human disease systemic lupus erythematosus (SLE). Groups of NZB/W F1 mice were treated either with IFN-gamma or with PBS. The results demonstrate that IFN-treated animals have accelerated development of fatal immune complex glomerulonephritis relative to age-matched controls. On the other hand, administration of mAbs specific for IFN-gamma to such mice from 4 to 7 mo of age resulted in significant remission. Development of both proteinuria and anti-DNA antibodies were delayed and survival at 11 mo was increased from less than 20% to 95% in treated mice relative to controls (p less than or equal to 0.001). These findings may have therapeutic implications for the treatment of SLE.

Animals↗
PubMed1987

Molecular mapping of class II polymorphisms in the human major histocompatibility complex. I. DR beta.

We have studied 27 cell lines homozygous by consanguinity for the major histocompatibility complex to establish the restriction fragment length polymorphism (RFLP) patterns seen with six different restriction enzymes (Bam HI, Bg1 II, Eco RI, Hinc II, Hind III, Pvu II) and DR beta chain probes. The probes used were a full-length cDNA DR beta probe and a probe specific for the 3' untranslated region. The RFLP obtained represent the first standard patterns for the individual haplotypes DR1 through 7 and DR9 as defined by genetically homozygous lines. The patterns obtained reflect the DR specificities closely, as well as the DRw52 and DRw53 specificities. These latter specificities are associated with the most prominent patterns of RFLP. Bands are present which are unique for the haplotypes DR1, DR2, DR4, DR7, DRw52, and DRw53, and could be used for typing these haplotypes in heterozygotes. Subtypes can be identified for all of the haplotypes except DR1. These subtypes indicate that there is an extensive amount of polymorphism in the DR subregion that has not been identified serologically.

Cell Line↗
PubMed1987

Molecular mapping class II polymorphisms in the human major histocompatibility complex. II. DQ beta.

The restriction fragment length polymorphisms have been determined for six restriction enzymes (Bam HI, Bg1 II, Eco RI, Hinc II, Hind III, and Pvu II) and a DQ beta probe on 25 cell lines that are homozygous by consanguinuity at the MHC. These patterns reflect both DR haplotypes and DQ types of the cells tested. At least one non-polymorphic band is present in all the cell lines with every restriction enzyme except Hinc II. This band most probably represents DX beta hybridization. The polymorphic bands indicate that more polymorphism exists in the DQ subregion than is predicted serologically. Each DR haplotype is associated with a unique set of restriction fragments except for DR2 and DR6. The patterns are largely consistent within each DR haplotype. In addition, some bands reflect the established DQ specificities DQw1 and DQw2. Individual bands can be identified that are unique to the haplotypes DR1, DR4, DR5, and DR6 and the DQw1- and DQw2-associated haplotypes. Subdivisions of haplotypes can be identified with this probe. In particular, MVL (DR1), Akiba (DR2), QBL (DR3), FPF (DR5), and APD (DR6) have polymorphisms that distinguish them from other members of their DR haplotype.

Cell Line↗
PubMed1987

Monoclonal anti-Ia antibody therapy in animal models of autoimmune disease.

Allele-specific monoclonal anti-I-A antibodies are capable of specifically suppressing the immune response to antigens under the control of the allele towards which the antibody is directed, without suppressing the response to antigens under the control of the alternative allele of the I-A alpha and beta chain genes in an F1 heterozygote. This phenomenon, which has been termed 'allele-specific immunosuppression', is antigen-specific, long-lasting and transferrable with Thy-1-positive spleen cells. This type of immunosuppression has been applied to animal models of autoimmune disease, in both homozygous and heterozygous animal models. Anti-I-A monoclonal antibodies are capable of preventing, suppressing and treating experimental allergic encephalomyelitis (EAE), of partially suppressing experimental autoimmune myasthenia gravis, and of preventing the onset of type I insulin-dependent diabetes in the BB/W diabetic rat. In addition, this type of immunotherapy has succeeded in almost completely suppressing nephritis in NZB X NZW F1 mice, which normally develop severe lupus-like nephritis. Significant toxicity, which may be due to anti-allotype antibodies, anti-idiotype antibodies, or to impurities in the monoclonal antibody preparations, has been encountered in the BB/W diabetic rat. In addition, attempts to extend these observations to EAE in the cynomolgus monkey have encountered significant mortality which appears to be attributable to the monoclonal antibody injections (anti-HLA-DR). The mechanism of this toxicity and means of circumventing it are currently under investigation. These results demonstrate the critical role of I-A molecules in the induction and continuance of the autoimmune process in these experimental animal models.

Animals↗
PubMed1987

HLA-DR restriction-fragment-length polymorphisms in narcolepsy.

Seventeen white patients from the Stanford Sleep Disorders Clinic complaining of excessive daytime somnolence (EDS) were selected for restriction-fragment-length polymorphism (RFLP) studies. Fourteen of the patients with clinically diagnosed narcolepsy were seropositive for DR2. RFLP analysis of these patients compared with a homozygous DR2-Dw2 cell line failed to reveal any polymorphism when digested with six restriction endonucleases and hybridized with three different cDNA probes. None of the three patients with central nervous system hypersomnia, a syndrome similar to narcolepsy, were DR2-positive. We conclude that any polymorphism of the DR beta, DQ alpha, or DQ beta genes of DR2 narcoleptics that might distinguish them from DR2 normals cannot be resolved through RFLP analysis.

HLA-D Antigens↗
PubMed1987

Structural and functional variability among DQ beta alleles of DR2 subtypes.

Homozygous lymphoblastoid cell lines representing various Dw subtypes of DR2 were examined for polymorphism at the DQ beta locus by molecular and cellular techniques. The subtypes studied included Dw2, Dw12, and a group heterogenous by cellular typing that we shall refer to as non-Dw2/non-Dw12. Restriction fragment length polymorphism analysis of cell lines representing these subtypes revealed DQ beta-specific patterns consistent with cellular typing. Two-dimensional gel electrophoresis of DQ molecules from representative cell lines revealed a structural polymorphism of DQ beta among the three subtypes. The DQ beta chain migrated to a position that was unique to each subtype and was consistent among various representative cell lines of each subtype. Nucleotide sequence analysis of cDNA clones of DQ beta from Dw2, Dw12, and non-Dw2/non-Dw12 lines confirmed that the variability resided at the genetic level. Variability was found in the form of numerous scattered nucleotide substitutions throughout the first domain of these alleles. The DQ beta gene of the non-Dw2/non-Dw12 cell line AZH was further found to be almost identical with the DQ beta gene of a DR1 line (Bell et al. 1985b), implicating a common evolutionary origin of these alleles. The only difference between these two sequences was due to an apparent gene conversion event at amino acid 57. T-cell cloning experiments resulted in the derivation of Epstein-Barr virus-specific, DQw1-restricted clones that proliferated against only those cell lines that exhibited the DQ beta gene common to AZH and the DR1 cell line. Thus, the polymorphism among DQ beta alleles within DR2 results in subtype-specific restriction.

Alleles↗
PubMed1987

HLA-DR2 subtypes form an additional supertypic family of DR beta alleles.

Homozygous lymphoblastoid cell lines representing Dw subtypes of the DR2 serotype were studied for structural polymorphism at DR beta. These subtypes included Dw2, Dw12, and non-Dw2/non-Dw12. Analysis by two-dimensional gel electrophoresis showed that two DR beta genes were expressed in each cell line studied. One of these expressed genes encoded a protein that was nonpolymorphic on two-dimensional gel electrophoresis among all subtypes. The second expressed DR beta gene was polymorphic and migrated to a position on two-dimensional gels dependent on the subtype of the cell line. cDNA sequence analysis of the DR beta genes revealed a DR beta gene identical between the Dw2 and Dw12 subtypes, which correlates with the nonpolymorphic spot on two-dimensional gels. A second gene was sequenced that exhibited variability between the Dw2 and Dw12 subtypes. This variability takes the form of clustered point mutations in the first domain of the molecules. The alleles from the DR beta genes of a non-Dw2/non-Dw12 cell line, AZH, were unusual in sequence. In contrast to other DR beta alleles, the AZH genes may have been generated by a double recombinational event between two DR beta loci from a DR2 parent. The DR2 serotype may also constitute a supertypic "family," with one DR beta gene relatively nonpolymorphic, and one that varies with Dw subtype.

Alleles↗
PubMed1987

Allelic variation in the DR subregion of the human major histocompatibility complex.

Allelic variation in the DR subregion of the human major histocompatibility complex has been analyzed by nucleic acid sequencing of cDNA clones obtained from cell lines homozygous by consanguinity for all the common serological types DR1-9. Two expressed loci were identified in the haplotypes DR2, -3, -4, -7, and -9; one locus being present at a much lower frequency (4-7%) than the other. The low-frequency allele was highly conserved between each of the DRw53 (DR4, -7, -9) and the DRw52 (DR3, -5, -6) haplotypes. Analysis of the variation between alleles confirms the presence of three allelic hypervariable regions. At each variable residue, a limited range of amino acid substitutions are found, distinguishing them from immunoglobulin hypervariable regions. Dinucleotide substitutions are extremely common. Individual hypervariable regions are often shared between haplotypes. Much of the variation in these alleles can be attributed to the shuffling of these regions between haplotypes, possibly by the mechanism of gene conversion.

Alleles↗
PubMed1987

The first external domain of the nonobese diabetic mouse class II I-A beta chain is unique.

The nonobese diabetic mouse is recognized as an important animal model for human insulin-dependent diabetes mellitus. One of the components of susceptibility to this disease has been mapped to the major histocompatibility complex. In this study, full-length cDNA clones encoding the I-A alpha and beta chains from the nonobese diabetic mouse have been isolated and sequenced. They are identical to the sequences previously determined from the H-2d haplotype except for the sequence encoding the first external domain, the leader peptide, and the 5' untranslated region of the I-A beta chain molecule. Most strikingly, there are five consecutive nucleotide substitutions which lead to two radical amino acid changes in a region that is conserved between human and mouse. We suggest that the unique structure of the first external I-A beta chain domain is a major determinant in the disease susceptibility that maps to the major histocompatibility complex of the nonobese diabetic mouse.

Amino Acid Sequence↗