Donna Ray | Texas Woman's University (original) (raw)

Papers by Donna Ray

Biological Procedures Online, 2003

Integrin adhesion molecules have important adhesion and signaling functions. They also play a cen... more Integrin adhesion molecules have important adhesion and signaling functions. They also play a central role in the pathogenesis of many autoimmune diseases. Over the past few years we have described a T cell adoptive transfer model to investigate the role of T cell integrin adhesion molecules in the development of autoimmunity. This report summarizes the methods we used in establishing this murine model. By treating murine CD4+ T cells with DNA hypomethylating agents and by transfection we were able to test thein vitro effects of integrin overexpression on T cell autoreactive proliferation, cytotoxicity, adhesion and trafficking. Furthermore, we showed that the ability to inducein vivo autoimmunity may be unique to the integrin lymphocyte function associated antigen-1 (LFA-1).

Arthritis and Rheumatism, 2001

Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by... more Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by modifying gene expression. T cells from patients with lupus exhibit diminished levels of DNA methyltransferase (MTase) enzyme activity, hypomethylated DNA, and changes in gene expression similar to those exhibited by T cells treated with methylation inhibitors, suggesting that DNA hypomethylation may contribute to human lupus. Since it is known that DNA MTase levels are regulated by the ras-mitogen-activated protein kinase (MAPK) pathway, this study sought to determine whether decreased ras-MAPK signaling could account for the DNA hypomethylation in lupus T cells.

Arthritis and Rheumatism, 2001

Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by... more Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by modifying gene expression. T cells from patients with lupus exhibit diminished levels of DNA methyltransferase (MTase) enzyme activity, hypomethylated DNA, and changes in gene expression similar to those exhibited by T cells treated with methylation inhibitors, suggesting that DNA hypomethylation may contribute to human lupus. Since it is known that DNA MTase levels are regulated by the ras-mitogen-activated protein kinase (MAPK) pathway, this study sought to determine whether decreased ras-MAPK signaling could account for the DNA hypomethylation in lupus T cells.

Clinical Immunology, 2008

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of au... more Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies against a host of nuclear antigens. The pathogenesis of lupus is incompletely understood. Environmental factors may play a role via altering DNA methylation, one mechanism regulating gene expression. In lupus, genes including CD11a and CD70 are overexpressed in T cells as a result of promoter hypomethylation. T cell DNA methyltransferase expression is regulated in part by the ERK signaling pathway. In this study, we investigate the effects of decreased ERK pathway signaling in T cells using transgenic animals. We generated a transgenic mouse that inducibly expresses a dominant negative MEK in T cells in the presence of doxycycline. We show that decreased ERK pathway signaling in Tcells results in decreased expression of DNA methyltransferase 1 and overexpression of the methylation sensitive genes CD11a and CD70, similar to Tcells in human lupus. Our transgenic animal model also develops anti-dsDNA antibodies. Interestingly, microarray expression assays revealed overexpression of several interferon-regulated genes in the spleen similar to peripheral blood cells of lupus patients. This model supports the contention that ERK pathway signaling defects in T cells contribute to the development of autoimmunity.

Clinical Reviews in Allergy & Immunology, 2010

The decline in immunocompetence with age is accompanied by the increase in the incidence of autoi... more The decline in immunocompetence with age is accompanied by the increase in the incidence of autoimmune diseases. Aging of the immune system, or immunosenescence, is characterized by a decline of both T and B cell function, and paradoxically the presence of low-grade chronic inflammation. There is growing evidence that epigenetics, the study of inherited changes in gene expression that are not encoded by the DNA sequence itself, changes with aging. Interestingly, emerging evidence suggests a key role for epigenetics in human pathologies, including inflammatory and neoplastic disorders. Here, we will review the potential mechanisms that contribute to the increase in autoimmune responses in aging. In particular, we will discuss how epigenetic alterations, especially DNA methylation and histone acetylation, are accumulated during aging and how these events contribute to autoimmunity risk.

We previously reported that heterozygous DNA methyltransferase 1-deficient (Dnmt1 þ/À ) mice main... more We previously reported that heterozygous DNA methyltransferase 1-deficient (Dnmt1 þ/À ) mice maintain T-cell immune function and DNA methylation levels with aging, whereas controls develop autoimmunity, immune senescence, and DNA hypomethylation. We therefore compared survival, cause of death, and T-cell DNA methylation gene expression during aging in Dnmt1 þ/À mice and controls. No difference in longevity was observed, but greater numbers of Dnmt1 þ/À mice developed jejunal apolipoprotein AII amyloidosis. Both groups showed decreased Dnmt1 expression with aging. However, expression of the de novo methyltransferases Dnmt3a and Dnmt3b increased with aging in stimulated T cells from control mice. MeCP2, a methylcytosine binding protein that participates in maintenance DNA methylation, increased with age in Dnmt1 þ/À mice, suggesting a mechanism for the sustained DNA methylation levels. This model thus provides potential mechanisms for DNA methylation changes of aging, and suggests that changes in DNA methylation may contribute to some forms of amyloidosis that develop with aging.

The studies summarized in this chapter demonstrate that the failure to maintain DNA methylation p... more The studies summarized in this chapter demonstrate that the failure to maintain DNA methylation patterns in mature CD4+ T cells causes aberrant expression of several methylation-sensitive genes, including LFA-1, perforin, CD70, and likely others, and that their overexpression alters T cell function, promoting autoreactivity, monocyte/macrophage killing, and B cell overstimulation. Furthermore, T cells experimentally demethylated with DNA methyltransferase or ERK signaling pathway inhibitors cause a lupus-like disease in murine models. Procainamide and hydralazine are DNA methylation inhibitors and cause a lupus-like disease in genetically susceptible individuals. Patients with idiopathic lupus have hypomethylated DNA, overexpress the same genes due to the same changes in DNA methylation patterns as in the methylation inhibition model, and demonstrate identical changes in CD4+ T cell function including autoreactive, perforin-mediated monocyte killing and B cell overstimulation. Thus, similar changes in DNA methylation and chromatin structure likely contribute to the pathogenesis of autoimmunity in the DNA hypomethylation model as in idiopathic lupus. The DNA hypomethylation model may also provide an approach to predict additional aberrantly expressed genes in human lupus T cells, since CD11a, perforin, and CD70 were predicted by this model. Finally, these studies also suggest that environmental agents may act by mechanisms analogous to those seen in DIL, triggering changes in chromatin structure and affecting gene expression through signaling inhibition or direct DNA methyltransferase inhibition. Clearly, there is a fundamental role for a failure to maintain DNA methylation patterns and chromatin structure in this disease.

Arthritis and Rheumatism, 2002

ObjectiveInhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like dis... more ObjectiveInhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like disease in vivo, suggesting that T cell DNA hypomethylation may contribute to autoimmunity. The hypomethylation effects are due, in part, to overexpression of lymphocyte function–associated antigen 1 (LFA-1) (CD11a/CD18). Importantly, T cells from patients with active lupus have hypomethylated DNA and overexpress LFA-1 on an autoreactive subset, suggesting that the same mechanism could contribute to human lupus. The present study investigated the nature of the methylation change that affects LFA-1 expression in vitro and in human lupus.Inhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like disease in vivo, suggesting that T cell DNA hypomethylation may contribute to autoimmunity. The hypomethylation effects are due, in part, to overexpression of lymphocyte function–associated antigen 1 (LFA-1) (CD11a/CD18). Importantly, T cells from patients with active lupus have hypomethylated DNA and overexpress LFA-1 on an autoreactive subset, suggesting that the same mechanism could contribute to human lupus. The present study investigated the nature of the methylation change that affects LFA-1 expression in vitro and in human lupus.MethodsBisulfite sequencing was used to determine the methylation status of the ITGAL promoter and flanking regions in T cells from lupus patients and healthy subjects, and in T cells treated with DNA methylation inhibitors. “Patch” methylation of promoter sequences in reporter constructs was used to determine the functional significance of the methylation changes.Bisulfite sequencing was used to determine the methylation status of the ITGAL promoter and flanking regions in T cells from lupus patients and healthy subjects, and in T cells treated with DNA methylation inhibitors. “Patch” methylation of promoter sequences in reporter constructs was used to determine the functional significance of the methylation changes.ResultsHypomethylation of specific sequences flanking the ITGAL promoter was seen in T cells from patients with active lupus and in T cells treated with 5-azacytidine and procainamide. Patch methylation of this region suppressed ITGAL promoter function.Hypomethylation of specific sequences flanking the ITGAL promoter was seen in T cells from patients with active lupus and in T cells treated with 5-azacytidine and procainamide. Patch methylation of this region suppressed ITGAL promoter function.ConclusionDNA methylation changes occur in specific sequences that regulate LFA-1 expression in lupus T cells and in the hypomethylation model, indicating that altered methylation of specific genes may play a role in the pathogenesis of lupus.DNA methylation changes occur in specific sequences that regulate LFA-1 expression in lupus T cells and in the hypomethylation model, indicating that altered methylation of specific genes may play a role in the pathogenesis of lupus.

Biological Procedures Online, 2003

Integrin adhesion molecules have important adhesion and signaling functions. They also play a cen... more Integrin adhesion molecules have important adhesion and signaling functions. They also play a central role in the pathogenesis of many autoimmune diseases. Over the past few years we have described a T cell adoptive transfer model to investigate the role of T cell integrin adhesion molecules in the development of autoimmunity. This report summarizes the methods we used in establishing this murine model. By treating murine CD4+ T cells with DNA hypomethylating agents and by transfection we were able to test thein vitro effects of integrin overexpression on T cell autoreactive proliferation, cytotoxicity, adhesion and trafficking. Furthermore, we showed that the ability to inducein vivo autoimmunity may be unique to the integrin lymphocyte function associated antigen-1 (LFA-1).

Arthritis and Rheumatism, 2001

Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by... more Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by modifying gene expression. T cells from patients with lupus exhibit diminished levels of DNA methyltransferase (MTase) enzyme activity, hypomethylated DNA, and changes in gene expression similar to those exhibited by T cells treated with methylation inhibitors, suggesting that DNA hypomethylation may contribute to human lupus. Since it is known that DNA MTase levels are regulated by the ras-mitogen-activated protein kinase (MAPK) pathway, this study sought to determine whether decreased ras-MAPK signaling could account for the DNA hypomethylation in lupus T cells.

Arthritis and Rheumatism, 2001

Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by... more Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by modifying gene expression. T cells from patients with lupus exhibit diminished levels of DNA methyltransferase (MTase) enzyme activity, hypomethylated DNA, and changes in gene expression similar to those exhibited by T cells treated with methylation inhibitors, suggesting that DNA hypomethylation may contribute to human lupus. Since it is known that DNA MTase levels are regulated by the ras-mitogen-activated protein kinase (MAPK) pathway, this study sought to determine whether decreased ras-MAPK signaling could account for the DNA hypomethylation in lupus T cells.

Clinical Immunology, 2008

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of au... more Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies against a host of nuclear antigens. The pathogenesis of lupus is incompletely understood. Environmental factors may play a role via altering DNA methylation, one mechanism regulating gene expression. In lupus, genes including CD11a and CD70 are overexpressed in T cells as a result of promoter hypomethylation. T cell DNA methyltransferase expression is regulated in part by the ERK signaling pathway. In this study, we investigate the effects of decreased ERK pathway signaling in T cells using transgenic animals. We generated a transgenic mouse that inducibly expresses a dominant negative MEK in T cells in the presence of doxycycline. We show that decreased ERK pathway signaling in Tcells results in decreased expression of DNA methyltransferase 1 and overexpression of the methylation sensitive genes CD11a and CD70, similar to Tcells in human lupus. Our transgenic animal model also develops anti-dsDNA antibodies. Interestingly, microarray expression assays revealed overexpression of several interferon-regulated genes in the spleen similar to peripheral blood cells of lupus patients. This model supports the contention that ERK pathway signaling defects in T cells contribute to the development of autoimmunity.

Clinical Reviews in Allergy & Immunology, 2010

The decline in immunocompetence with age is accompanied by the increase in the incidence of autoi... more The decline in immunocompetence with age is accompanied by the increase in the incidence of autoimmune diseases. Aging of the immune system, or immunosenescence, is characterized by a decline of both T and B cell function, and paradoxically the presence of low-grade chronic inflammation. There is growing evidence that epigenetics, the study of inherited changes in gene expression that are not encoded by the DNA sequence itself, changes with aging. Interestingly, emerging evidence suggests a key role for epigenetics in human pathologies, including inflammatory and neoplastic disorders. Here, we will review the potential mechanisms that contribute to the increase in autoimmune responses in aging. In particular, we will discuss how epigenetic alterations, especially DNA methylation and histone acetylation, are accumulated during aging and how these events contribute to autoimmunity risk.

We previously reported that heterozygous DNA methyltransferase 1-deficient (Dnmt1 þ/À ) mice main... more We previously reported that heterozygous DNA methyltransferase 1-deficient (Dnmt1 þ/À ) mice maintain T-cell immune function and DNA methylation levels with aging, whereas controls develop autoimmunity, immune senescence, and DNA hypomethylation. We therefore compared survival, cause of death, and T-cell DNA methylation gene expression during aging in Dnmt1 þ/À mice and controls. No difference in longevity was observed, but greater numbers of Dnmt1 þ/À mice developed jejunal apolipoprotein AII amyloidosis. Both groups showed decreased Dnmt1 expression with aging. However, expression of the de novo methyltransferases Dnmt3a and Dnmt3b increased with aging in stimulated T cells from control mice. MeCP2, a methylcytosine binding protein that participates in maintenance DNA methylation, increased with age in Dnmt1 þ/À mice, suggesting a mechanism for the sustained DNA methylation levels. This model thus provides potential mechanisms for DNA methylation changes of aging, and suggests that changes in DNA methylation may contribute to some forms of amyloidosis that develop with aging.

The studies summarized in this chapter demonstrate that the failure to maintain DNA methylation p... more The studies summarized in this chapter demonstrate that the failure to maintain DNA methylation patterns in mature CD4+ T cells causes aberrant expression of several methylation-sensitive genes, including LFA-1, perforin, CD70, and likely others, and that their overexpression alters T cell function, promoting autoreactivity, monocyte/macrophage killing, and B cell overstimulation. Furthermore, T cells experimentally demethylated with DNA methyltransferase or ERK signaling pathway inhibitors cause a lupus-like disease in murine models. Procainamide and hydralazine are DNA methylation inhibitors and cause a lupus-like disease in genetically susceptible individuals. Patients with idiopathic lupus have hypomethylated DNA, overexpress the same genes due to the same changes in DNA methylation patterns as in the methylation inhibition model, and demonstrate identical changes in CD4+ T cell function including autoreactive, perforin-mediated monocyte killing and B cell overstimulation. Thus, similar changes in DNA methylation and chromatin structure likely contribute to the pathogenesis of autoimmunity in the DNA hypomethylation model as in idiopathic lupus. The DNA hypomethylation model may also provide an approach to predict additional aberrantly expressed genes in human lupus T cells, since CD11a, perforin, and CD70 were predicted by this model. Finally, these studies also suggest that environmental agents may act by mechanisms analogous to those seen in DIL, triggering changes in chromatin structure and affecting gene expression through signaling inhibition or direct DNA methyltransferase inhibition. Clearly, there is a fundamental role for a failure to maintain DNA methylation patterns and chromatin structure in this disease.

Arthritis and Rheumatism, 2002

ObjectiveInhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like dis... more ObjectiveInhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like disease in vivo, suggesting that T cell DNA hypomethylation may contribute to autoimmunity. The hypomethylation effects are due, in part, to overexpression of lymphocyte function–associated antigen 1 (LFA-1) (CD11a/CD18). Importantly, T cells from patients with active lupus have hypomethylated DNA and overexpress LFA-1 on an autoreactive subset, suggesting that the same mechanism could contribute to human lupus. The present study investigated the nature of the methylation change that affects LFA-1 expression in vitro and in human lupus.Inhibition of T cell DNA methylation causes autoreactivity in vitro and a lupus-like disease in vivo, suggesting that T cell DNA hypomethylation may contribute to autoimmunity. The hypomethylation effects are due, in part, to overexpression of lymphocyte function–associated antigen 1 (LFA-1) (CD11a/CD18). Importantly, T cells from patients with active lupus have hypomethylated DNA and overexpress LFA-1 on an autoreactive subset, suggesting that the same mechanism could contribute to human lupus. The present study investigated the nature of the methylation change that affects LFA-1 expression in vitro and in human lupus.MethodsBisulfite sequencing was used to determine the methylation status of the ITGAL promoter and flanking regions in T cells from lupus patients and healthy subjects, and in T cells treated with DNA methylation inhibitors. “Patch” methylation of promoter sequences in reporter constructs was used to determine the functional significance of the methylation changes.Bisulfite sequencing was used to determine the methylation status of the ITGAL promoter and flanking regions in T cells from lupus patients and healthy subjects, and in T cells treated with DNA methylation inhibitors. “Patch” methylation of promoter sequences in reporter constructs was used to determine the functional significance of the methylation changes.ResultsHypomethylation of specific sequences flanking the ITGAL promoter was seen in T cells from patients with active lupus and in T cells treated with 5-azacytidine and procainamide. Patch methylation of this region suppressed ITGAL promoter function.Hypomethylation of specific sequences flanking the ITGAL promoter was seen in T cells from patients with active lupus and in T cells treated with 5-azacytidine and procainamide. Patch methylation of this region suppressed ITGAL promoter function.ConclusionDNA methylation changes occur in specific sequences that regulate LFA-1 expression in lupus T cells and in the hypomethylation model, indicating that altered methylation of specific genes may play a role in the pathogenesis of lupus.DNA methylation changes occur in specific sequences that regulate LFA-1 expression in lupus T cells and in the hypomethylation model, indicating that altered methylation of specific genes may play a role in the pathogenesis of lupus.