Harout DerSimonian - Academia.edu (original) (raw)

Papers by Harout DerSimonian

Journal of Immunology, Oct 1, 1987

In order to identify the V region genes encoding systemic lupus erythematosus (SLE)-derived anti-... more In order to identify the V region genes encoding systemic lupus erythematosus (SLE)-derived anti-DNA autoantibodies, we have determined the nucleotide sequence of heavy chain mRNA from several DNA-binding immunoglobulins secreted by human hybridomas. We used the technique of cDNA primer extension for determining sequences of the VH, D, and JH gene segments of anti-DNA autoantibodies from three different primary hybridoma growths from an SLE patient and one hybridoma from a leprosy patient. Immunoglobulins from two of the SLE hybridomas expressed the same idiotype, Id-16/6, which is also expressed on immunoglobulins in sera of patients with active SLE. Their mRNA sequences showed complete homology to each other in the V, D, and J genes and more than 99% homology to the VH26 germ-line gene sequence, a member of the human VHIII gene family. The VH mRNA sequence of the third SLE hybridoma, 21/28, which was idiotypically unrelated to the other two, was 93% homologous to a different VH germ-line gene sequence, HA2, a member of the human VHI gene family. The fourth anti-DNA-producing hybridoma, 8E10, was derived from a leprosy patient of different ethnic origin than the SLE patient. It was idiotypically related to 21/28 and expressed a VH segment gene identical to that of 21/28. Hybridomas 21/28 and 8E10 shared sequence homology with the VH26 anti-DNA antibodies in the first complementarity-determining region. In addition, 21/28 shared sequence homology with the Id-16/6+ group in the region encoded by the D and J gene segments. Our findings indicate that some SLE autoantibodies are encoded by unmodified or scarcely modified VH germ-line genes that are conserved in the human population and identify two distinct VH germ-line genes that can encode segments of anti-DNA immunoglobulins.

International Reviews of Immunology, 1990

ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline... more ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline V genes that contribute to the immunoglobulin repertoire in normal persons, whether they stem from “abnormal” V genes that are peculiar to patients with autoimmune diseases, and whether they are encoded by unmodified or somatically mutated immunoglobulin genes. These issues influence the way we think about three aspects of autoimmunity: genetic susceptibility to autoimmunization, the origins of lesion-producing autoantibodies, and the prevention and medical management of autoimmune disorders.

Journal of Immunology, Jun 1, 1989

Identi cation and sequence of the VH gene elements encoding a human anti-DNA antibody.

The Journal of Immunology

RNA sequences for the V regions of human hybridoma-produced autoantibodies were determined by pri... more RNA sequences for the V regions of human hybridoma-produced autoantibodies were determined by primer extension with reverse transcriptase. The sequencing of IgM autoantibodies from a leprosy patient revealed examples of recurrent use of V region gene segments in different autoantibodies from this patient and a previously studied patient with SLE. Moreover, several gene segments used in these autoantibodies show little alteration from germ-line sequences. mAb TH3, from a patient with leprosy, binds denatured DNA and poly(dT). The center of its H chain CDR35 has a sequence identical to that found previously in two anti-DNA antibodies from a lupus patient; these identities and their overlapping with two other published sequences define a human D-gene segment of approximately 25 nucleotides. Autoantibody TH9, from a leprosy patient, does not bind DNA. Its VH sequence has 87% identity with a VHI anti-DNA antibody, but differs from it markedly in the CDR1 region. TH9 also has a different ...

Xenotransplantation, 2002

Transplantation, 1997

The cell surface carbohydrate moiety, Gal(alpha1,3)Galactose (alphaGal), has been implicated as t... more The cell surface carbohydrate moiety, Gal(alpha1,3)Galactose (alphaGal), has been implicated as the major determinant recognized by more than 80% of human anti-porcine natural antibodies (NAb). An ELISA system was developed for the detection of this subpopulation of porcine cell-reactive NAb using synthetic alphaGal conjugated to bovine serum albumin. A screen of 95 human serum samples by this method demonstrated marked variability in the alphaGal reactivity of unrelated donors. The percentage of alphaGal-reactive NAb relative to total immunoglobulin was determined for 10 donors. alphaGal-reactive NAb comprised 1.0-2.4% of total serum IgG, whereas the range was from 3.9% to 8.0% for IgM. The higher level of alphaGal-reactive IgM suggests that xenoreactive NAbs may be the product of germ-line genes. Two-dimensional gel analysis of affinity-purified alphaGal-reactive NAb from two donors provided evidence suggesting that IgM from this subpopulation of NAb were restricted in protein charge heterogeneity.

Circulation, 2001

Background —Myocardial infarction (MI) promotes deleterious remodeling of the myocardium, resulti... more Background —Myocardial infarction (MI) promotes deleterious remodeling of the myocardium, resulting in ventricular dilation and pump dysfunction. We examined whether supplementing infarcted myocardium with skeletal myoblasts would (1) result in viable myoblast implants, (2) attenuate deleterious remodeling, and (3) enhance in vivo and ex vivo contractile performance. Methods and Results —Experimental MI was induced by 1-hour coronary ligation followed by reperfusion in adult male Lewis rats. One week after MI, 10 6 myoblasts were injected directly into the infarct region. Three groups of animals were studied at 3 and 6 weeks after cell therapy: noninfarcted control (control), MI plus sham injection (MI), and MI plus cell injection (MI+cell). In vivo cardiac function was assessed by maximum exercise capacity testing and ex vivo function was determined by pressure-volume curves obtained from isolated, red cell–perfused, balloon–in–left ventricle (LV) hearts. MI and MI+cell hearts had ...

The Journal of Heart and Lung Transplantation, 2003

Scientific reports, Jan 7, 2018

Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Cu... more Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Current reconstruction approaches are limited to utilization of an autologous conduit such as stomach, small bowel, or colon. A tissue engineered construct providing an alternative for esophageal replacement in circumferential, full thickness resection would have significant clinical applications. In the current study, we demonstrate that regeneration of esophageal tissue is feasible and reproducible in a large animal model using synthetic polyurethane electro-spun grafts seeded with autologous adipose-derived mesenchymal stem cells (aMSCs) and a disposable bioreactor. The scaffolds were not incorporated into the regrown esophageal tissue and were retrieved endoscopically. Animals underwent adipose tissue biopsy to harvest and expand autologous aMSCs for seeding on electro-spun polyurethane conduits in a bioreactor. Anesthetized pigs underwent full thickness circumferential resection of th...

Transplantation Proceedings, May 1, 1996

Transplantation, Aug 15, 1997

Background: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine g... more Background: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine glycoproteins and glycolipids, but is not expressed by human cells. Consequently human sera contain anti-alphaGal natural antibodies. The human blood group B antigen [Gal alpha1,3(Fuc1,2)Galactose] is differentiated from the alphaGal epitope by the presence of a fucosyl group. Methods: To determine whether the expression of the B antigen has any effect on the level of alphaGal-reactive natural antibodies, equal numbers (n=12) of A, B, AB, and O serum samples were evaluated by ELISA and flow cytometry. Results: A significant reduction in IgG alphaGal reactivity was observed with serum samples from B antigen-expressing donors (B, AB) relative to non-B antigen-expressing donors (A, O). Conclusions: These results are consistent with the possibility that anti-alphaGal antibodies in non-B antigen-expressing individuals include a subset that is reactive with the structurally related B antigen and that this subset is absent in B and AB individuals.

ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline... more ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline V genes that contribute to the immunoglobulin repertoire in normal persons, whether they stem from “abnormal” V genes that are peculiar to patients with autoimmune diseases, and whether they are encoded by unmodified or somatically mutated immunoglobulin genes. These issues influence the way we think about three aspects of autoimmunity: genetic susceptibility to autoimmunization, the origins of lesion-producing autoantibodies, and the prevention and medical management of autoimmune disorders.

Transplantation Proceedings, May 1, 1996

The Journal of Immunology, Dec 1, 1995

Partially inbred, MHC homozygous miniature swine have been used to study the nature of the human ... more Partially inbred, MHC homozygous miniature swine have been used to study the nature of the human xenogeneic cellular immune response to swine Ags in vitro. Human T cells responded to xeno-MHC Ags in MLR at least as well as they did to allo-MHC Ags and appeared to share similar requirements for APC of either stimulator (direct pathway) or responder (indirect pathway) derivation. In addition, mAb-blocking experiments indicated that the majority of the primary human anti-pig xeno-response was directed toward porcine MHC class II Ags and involved interaction with the human CD4 accessory molecule. Finally, the availability of intra-MHC recombinant haplotypes in our herds has made it possible to map genetically the antigenic specificities recognized in human anti-swine cellular responses. For this purpose, T cell clones were generated from human anti-swine MLR cultures and were tested for reactivity to stimulator cells from MHC homozygous and recombinant haplotypes. Clear evidence for antixenogeneic MHC Ags was observed. In all cases in which allelic differences between haplotypes were detected (the majority of clones), the reactivity could be mapped to the class II region of stimulator haplotypes. In addition, cross-reactivity between haplotypes was consistent with known sequence similarities between DR beta-chains. Our results indicate, therefore, that the human anti-porcine T cell response is similar in strength and specificity to an allogeneic response, and that the TCR repertoire, accessory molecule interactions, and cytokine production required for both direct and indirect pathways of recognition in the human anti-porcine MHC class II responses are functionally intact.

Journal of Immunology, Oct 1, 1987

In order to identify the V region genes encoding systemic lupus erythematosus (SLE)-derived anti-... more In order to identify the V region genes encoding systemic lupus erythematosus (SLE)-derived anti-DNA autoantibodies, we have determined the nucleotide sequence of heavy chain mRNA from several DNA-binding immunoglobulins secreted by human hybridomas. We used the technique of cDNA primer extension for determining sequences of the VH, D, and JH gene segments of anti-DNA autoantibodies from three different primary hybridoma growths from an SLE patient and one hybridoma from a leprosy patient. Immunoglobulins from two of the SLE hybridomas expressed the same idiotype, Id-16/6, which is also expressed on immunoglobulins in sera of patients with active SLE. Their mRNA sequences showed complete homology to each other in the V, D, and J genes and more than 99% homology to the VH26 germ-line gene sequence, a member of the human VHIII gene family. The VH mRNA sequence of the third SLE hybridoma, 21/28, which was idiotypically unrelated to the other two, was 93% homologous to a different VH germ-line gene sequence, HA2, a member of the human VHI gene family. The fourth anti-DNA-producing hybridoma, 8E10, was derived from a leprosy patient of different ethnic origin than the SLE patient. It was idiotypically related to 21/28 and expressed a VH segment gene identical to that of 21/28. Hybridomas 21/28 and 8E10 shared sequence homology with the VH26 anti-DNA antibodies in the first complementarity-determining region. In addition, 21/28 shared sequence homology with the Id-16/6+ group in the region encoded by the D and J gene segments. Our findings indicate that some SLE autoantibodies are encoded by unmodified or scarcely modified VH germ-line genes that are conserved in the human population and identify two distinct VH germ-line genes that can encode segments of anti-DNA immunoglobulins.

International Reviews of Immunology, 1990

ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline... more ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline V genes that contribute to the immunoglobulin repertoire in normal persons, whether they stem from “abnormal” V genes that are peculiar to patients with autoimmune diseases, and whether they are encoded by unmodified or somatically mutated immunoglobulin genes. These issues influence the way we think about three aspects of autoimmunity: genetic susceptibility to autoimmunization, the origins of lesion-producing autoantibodies, and the prevention and medical management of autoimmune disorders.

Journal of Immunology, Jun 1, 1989

Identi cation and sequence of the VH gene elements encoding a human anti-DNA antibody.

The Journal of Immunology

RNA sequences for the V regions of human hybridoma-produced autoantibodies were determined by pri... more RNA sequences for the V regions of human hybridoma-produced autoantibodies were determined by primer extension with reverse transcriptase. The sequencing of IgM autoantibodies from a leprosy patient revealed examples of recurrent use of V region gene segments in different autoantibodies from this patient and a previously studied patient with SLE. Moreover, several gene segments used in these autoantibodies show little alteration from germ-line sequences. mAb TH3, from a patient with leprosy, binds denatured DNA and poly(dT). The center of its H chain CDR35 has a sequence identical to that found previously in two anti-DNA antibodies from a lupus patient; these identities and their overlapping with two other published sequences define a human D-gene segment of approximately 25 nucleotides. Autoantibody TH9, from a leprosy patient, does not bind DNA. Its VH sequence has 87% identity with a VHI anti-DNA antibody, but differs from it markedly in the CDR1 region. TH9 also has a different ...

Xenotransplantation, 2002

Transplantation, 1997

The cell surface carbohydrate moiety, Gal(alpha1,3)Galactose (alphaGal), has been implicated as t... more The cell surface carbohydrate moiety, Gal(alpha1,3)Galactose (alphaGal), has been implicated as the major determinant recognized by more than 80% of human anti-porcine natural antibodies (NAb). An ELISA system was developed for the detection of this subpopulation of porcine cell-reactive NAb using synthetic alphaGal conjugated to bovine serum albumin. A screen of 95 human serum samples by this method demonstrated marked variability in the alphaGal reactivity of unrelated donors. The percentage of alphaGal-reactive NAb relative to total immunoglobulin was determined for 10 donors. alphaGal-reactive NAb comprised 1.0-2.4% of total serum IgG, whereas the range was from 3.9% to 8.0% for IgM. The higher level of alphaGal-reactive IgM suggests that xenoreactive NAbs may be the product of germ-line genes. Two-dimensional gel analysis of affinity-purified alphaGal-reactive NAb from two donors provided evidence suggesting that IgM from this subpopulation of NAb were restricted in protein charge heterogeneity.

Circulation, 2001

Background —Myocardial infarction (MI) promotes deleterious remodeling of the myocardium, resulti... more Background —Myocardial infarction (MI) promotes deleterious remodeling of the myocardium, resulting in ventricular dilation and pump dysfunction. We examined whether supplementing infarcted myocardium with skeletal myoblasts would (1) result in viable myoblast implants, (2) attenuate deleterious remodeling, and (3) enhance in vivo and ex vivo contractile performance. Methods and Results —Experimental MI was induced by 1-hour coronary ligation followed by reperfusion in adult male Lewis rats. One week after MI, 10 6 myoblasts were injected directly into the infarct region. Three groups of animals were studied at 3 and 6 weeks after cell therapy: noninfarcted control (control), MI plus sham injection (MI), and MI plus cell injection (MI+cell). In vivo cardiac function was assessed by maximum exercise capacity testing and ex vivo function was determined by pressure-volume curves obtained from isolated, red cell–perfused, balloon–in–left ventricle (LV) hearts. MI and MI+cell hearts had ...

The Journal of Heart and Lung Transplantation, 2003

Scientific reports, Jan 7, 2018

Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Cu... more Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Current reconstruction approaches are limited to utilization of an autologous conduit such as stomach, small bowel, or colon. A tissue engineered construct providing an alternative for esophageal replacement in circumferential, full thickness resection would have significant clinical applications. In the current study, we demonstrate that regeneration of esophageal tissue is feasible and reproducible in a large animal model using synthetic polyurethane electro-spun grafts seeded with autologous adipose-derived mesenchymal stem cells (aMSCs) and a disposable bioreactor. The scaffolds were not incorporated into the regrown esophageal tissue and were retrieved endoscopically. Animals underwent adipose tissue biopsy to harvest and expand autologous aMSCs for seeding on electro-spun polyurethane conduits in a bioreactor. Anesthetized pigs underwent full thickness circumferential resection of th...

Transplantation Proceedings, May 1, 1996

Transplantation, Aug 15, 1997

Background: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine g... more Background: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine glycoproteins and glycolipids, but is not expressed by human cells. Consequently human sera contain anti-alphaGal natural antibodies. The human blood group B antigen [Gal alpha1,3(Fuc1,2)Galactose] is differentiated from the alphaGal epitope by the presence of a fucosyl group. Methods: To determine whether the expression of the B antigen has any effect on the level of alphaGal-reactive natural antibodies, equal numbers (n=12) of A, B, AB, and O serum samples were evaluated by ELISA and flow cytometry. Results: A significant reduction in IgG alphaGal reactivity was observed with serum samples from B antigen-expressing donors (B, AB) relative to non-B antigen-expressing donors (A, O). Conclusions: These results are consistent with the possibility that anti-alphaGal antibodies in non-B antigen-expressing individuals include a subset that is reactive with the structurally related B antigen and that this subset is absent in B and AB individuals.

ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline... more ABSTRACT Important questions about pathogenic autoantibodies are whether they arise from germline V genes that contribute to the immunoglobulin repertoire in normal persons, whether they stem from “abnormal” V genes that are peculiar to patients with autoimmune diseases, and whether they are encoded by unmodified or somatically mutated immunoglobulin genes. These issues influence the way we think about three aspects of autoimmunity: genetic susceptibility to autoimmunization, the origins of lesion-producing autoantibodies, and the prevention and medical management of autoimmune disorders.

Transplantation Proceedings, May 1, 1996

The Journal of Immunology, Dec 1, 1995

Partially inbred, MHC homozygous miniature swine have been used to study the nature of the human ... more Partially inbred, MHC homozygous miniature swine have been used to study the nature of the human xenogeneic cellular immune response to swine Ags in vitro. Human T cells responded to xeno-MHC Ags in MLR at least as well as they did to allo-MHC Ags and appeared to share similar requirements for APC of either stimulator (direct pathway) or responder (indirect pathway) derivation. In addition, mAb-blocking experiments indicated that the majority of the primary human anti-pig xeno-response was directed toward porcine MHC class II Ags and involved interaction with the human CD4 accessory molecule. Finally, the availability of intra-MHC recombinant haplotypes in our herds has made it possible to map genetically the antigenic specificities recognized in human anti-swine cellular responses. For this purpose, T cell clones were generated from human anti-swine MLR cultures and were tested for reactivity to stimulator cells from MHC homozygous and recombinant haplotypes. Clear evidence for antixenogeneic MHC Ags was observed. In all cases in which allelic differences between haplotypes were detected (the majority of clones), the reactivity could be mapped to the class II region of stimulator haplotypes. In addition, cross-reactivity between haplotypes was consistent with known sequence similarities between DR beta-chains. Our results indicate, therefore, that the human anti-porcine T cell response is similar in strength and specificity to an allogeneic response, and that the TCR repertoire, accessory molecule interactions, and cytokine production required for both direct and indirect pathways of recognition in the human anti-porcine MHC class II responses are functionally intact.