Marshall Behrens | Mayo Clinic Graduate School (original) (raw)
Uploads
Papers by Marshall Behrens
Journal of Molecular and Cellular Cardiology, 2007
Most individuals have viral infections at some point in their life, however, only few develop aut... more Most individuals have viral infections at some point in their life, however, only few develop autoreactivity to cardiac myosin following infection resulting in myocarditis suggesting a genetic predisposition. Most mouse models of myocarditis are induced by viral infection or by immunization with cardiac myosin. We generated HLA-DR3.Aβo and HLA-DQ8.Aβo transgenic mice in NOD and HLA-DQ8.Aβo in B10 background to study spontaneous autoimmunity. A high mortality was observed in NOD.DQ8 female mice 16 weeks or older. Echocardiography showed marked systolic dysfunction. Histopathology of various organs revealed an enlarged heart with mononuclear infiltrate consisting of CD4 and Mac-1+ cells and myocyte necrosis. The autoimmunity was associated with the presence of spontaneous autoreactive T cells and antibodies to cardiac myosin. Serologically, mice were negative for all known mouse viruses. NOD.DR3.Aβo, the transgene negative littermates, NOD, and B10.DQ8 Aβo mice had no gross or microscopic cardiac pathology. Spontaneous cellular and humoral response to cardiac myosin suggest that NOD.DQ8 may harbor autoreative cells that can lead to spontaneous myocarditis and dilated cardiomyopathy. HLA-DQ8 is required for predisposition to the spontaneous autoreactivity while NOD background influences onset and progression of disease. This model of myocarditis occurs predominantly in female mice and may provide insight into the pathogenesis of heart disease in women.
Arthritis and Rheumatism, 2007
ObjectiveTo generate a mouse model that can mimic human rheumatoid arthritis (RA). A major differ... more ObjectiveTo generate a mouse model that can mimic human rheumatoid arthritis (RA). A major difference between RA in humans and collagen-induced arthritis (CIA) in mice is the lack of sex bias and autoantibodies in the animal model. We used DRB1*0401-transgenic mice to understand the role of DR4 in susceptibility and sex bias in RA.To generate a mouse model that can mimic human rheumatoid arthritis (RA). A major difference between RA in humans and collagen-induced arthritis (CIA) in mice is the lack of sex bias and autoantibodies in the animal model. We used DRB1*0401-transgenic mice to understand the role of DR4 in susceptibility and sex bias in RA.MethodsA transgenic mouse was generated that lacked all endogenous mouse class II genes (AEo) and expressed the RA susceptibility allele HLA–DRB1*0401. These transgenic mice were tested for incidence, severity, and sex distribution of CIA.A transgenic mouse was generated that lacked all endogenous mouse class II genes (AEo) and expressed the RA susceptibility allele HLA–DRB1*0401. These transgenic mice were tested for incidence, severity, and sex distribution of CIA.ResultsDRB1*0401.AEo mice developed CIA predominantly in females and produced rheumatoid factors, similar to the features of human RA. Another feature similar to human RA is the expression of class II molecules on antigen-presenting cells as well as T cells. Activated and sorted CD4+ T cells can present DR4-restricted type II collagen (CII)–derived peptide in vitro, but cannot process the antigen. This suggests a role for these cells in epitope presentation locally in joints, which affects disease severity. After challenge with CII, female mice had higher cellularity and increased T cell proliferation and produced higher levels of proinflammatory cytokines than did the male mice.DRB1*0401.AEo mice developed CIA predominantly in females and produced rheumatoid factors, similar to the features of human RA. Another feature similar to human RA is the expression of class II molecules on antigen-presenting cells as well as T cells. Activated and sorted CD4+ T cells can present DR4-restricted type II collagen (CII)–derived peptide in vitro, but cannot process the antigen. This suggests a role for these cells in epitope presentation locally in joints, which affects disease severity. After challenge with CII, female mice had higher cellularity and increased T cell proliferation and produced higher levels of proinflammatory cytokines than did the male mice.ConclusionDR4.AEo mice expressed HLA similar to humans and displayed increased arthritis susceptibility in females, thus mimicking RA in humans. This model may be valuable for studying sex differences observed in humans and for understanding why autoimmunity is increased in women. These mice may also be useful for developing future therapeutic strategies.DR4.AEo mice expressed HLA similar to humans and displayed increased arthritis susceptibility in females, thus mimicking RA in humans. This model may be valuable for studying sex differences observed in humans and for understanding why autoimmunity is increased in women. These mice may also be useful for developing future therapeutic strategies.
Journal of Autoimmunity, 2011
Population studies have shown that amongst all the genetic factors linked with autoimmune disease... more Population studies have shown that amongst all the genetic factors linked with autoimmune disease development, MHC class II genes are the most significant. Experimental autoimmune arthritis resembling human rheumatoid arthritis (RA) can be induced in susceptible strains of mice following immunization with type II collagen (CIA). We generated transgenic mice lacking endogenous class II molecules and expressing various HLA genes including RA-associated, HLA-DRB1*0401 and HLA-DQ8, and RA-resistant, DRB1*0402, genes. The HLA molecules in these mice are expressed on the cell surface and can positively select CD4+ T cells expressing various Vβ T cell receptors. Endogenous class II invariant chain is required for proper functioning of the class II transgene. Arthritis development in transgenic mice is CD4+ and B cells dependent. Studies in humanized mice showed that B cells are required as antigen presenting cells in addition to antibody producing cells for the development of CIA. The transgenic mice expressing *0401 and *0401/DQ8 genes developed sex-biased arthritis with predominantly females being affected, similar to that of human RA. Further, the transgenic mice produced autoantibodies like rheumatoid factor and anti-cyclic antibodies. Antigen presentation by B cells leads to a sex specific immune response in DRB1*0401 mice suggesting a role of B cells and HLA-DR in rendering susceptibility to develop arthritis in females.
Journal of Autoimmunity, 2010
HLA class II allele DRB1*0401 is associated with predisposition to Rheumatoid Arthritis in humans... more HLA class II allele DRB1*0401 is associated with predisposition to Rheumatoid Arthritis in humans as well as collagen-induced arthritis in mice. Predominantly females develop arthritis in humans and DR4 transgenic mice; however the mechanism of sex-bias is still unknown. We have investigated the molecular basis by which DR4 is associated with sex-bias of arthritis. Here we show that differential antigen-specific immune mechanisms in DR4 male and female mice lead to increased susceptibility in female mice. B cells are hyperactive and present DR-restricted peptides robustly in females compared to males. Antigen-specific response showed that females produced B cell modulating cytokines like IL-13 while males produced IFNγ. Male transgenic mice have higher number of T and B regulatory cells. An exogenous supply of 17β estradiol in male mice led to enhanced expression of DR4 and antigen-specific response to DR4-restricted peptides. On the other hand, castration increased the incidence of arthritis. We propose that sex-bias in arthritis involves B cells and presentation of antigen by HLA-DR4 leading to activation of autoreactive cells and autoantibodies production in females, while regulatory B cells in males protect them from pathogenesis. The transgenic mice expressing RA susceptible haplotype simulate human RA and may be valuable to study gender differences observed in patients.
Journal of Clinical Investigation, 2003
Journal of Molecular and Cellular Cardiology, 2007
Most individuals have viral infections at some point in their life, however, only few develop aut... more Most individuals have viral infections at some point in their life, however, only few develop autoreactivity to cardiac myosin following infection resulting in myocarditis suggesting a genetic predisposition. Most mouse models of myocarditis are induced by viral infection or by immunization with cardiac myosin. We generated HLA-DR3.Aβo and HLA-DQ8.Aβo transgenic mice in NOD and HLA-DQ8.Aβo in B10 background to study spontaneous autoimmunity. A high mortality was observed in NOD.DQ8 female mice 16 weeks or older. Echocardiography showed marked systolic dysfunction. Histopathology of various organs revealed an enlarged heart with mononuclear infiltrate consisting of CD4 and Mac-1+ cells and myocyte necrosis. The autoimmunity was associated with the presence of spontaneous autoreactive T cells and antibodies to cardiac myosin. Serologically, mice were negative for all known mouse viruses. NOD.DR3.Aβo, the transgene negative littermates, NOD, and B10.DQ8 Aβo mice had no gross or microscopic cardiac pathology. Spontaneous cellular and humoral response to cardiac myosin suggest that NOD.DQ8 may harbor autoreative cells that can lead to spontaneous myocarditis and dilated cardiomyopathy. HLA-DQ8 is required for predisposition to the spontaneous autoreactivity while NOD background influences onset and progression of disease. This model of myocarditis occurs predominantly in female mice and may provide insight into the pathogenesis of heart disease in women.
Arthritis and Rheumatism, 2007
ObjectiveTo generate a mouse model that can mimic human rheumatoid arthritis (RA). A major differ... more ObjectiveTo generate a mouse model that can mimic human rheumatoid arthritis (RA). A major difference between RA in humans and collagen-induced arthritis (CIA) in mice is the lack of sex bias and autoantibodies in the animal model. We used DRB1*0401-transgenic mice to understand the role of DR4 in susceptibility and sex bias in RA.To generate a mouse model that can mimic human rheumatoid arthritis (RA). A major difference between RA in humans and collagen-induced arthritis (CIA) in mice is the lack of sex bias and autoantibodies in the animal model. We used DRB1*0401-transgenic mice to understand the role of DR4 in susceptibility and sex bias in RA.MethodsA transgenic mouse was generated that lacked all endogenous mouse class II genes (AEo) and expressed the RA susceptibility allele HLA–DRB1*0401. These transgenic mice were tested for incidence, severity, and sex distribution of CIA.A transgenic mouse was generated that lacked all endogenous mouse class II genes (AEo) and expressed the RA susceptibility allele HLA–DRB1*0401. These transgenic mice were tested for incidence, severity, and sex distribution of CIA.ResultsDRB1*0401.AEo mice developed CIA predominantly in females and produced rheumatoid factors, similar to the features of human RA. Another feature similar to human RA is the expression of class II molecules on antigen-presenting cells as well as T cells. Activated and sorted CD4+ T cells can present DR4-restricted type II collagen (CII)–derived peptide in vitro, but cannot process the antigen. This suggests a role for these cells in epitope presentation locally in joints, which affects disease severity. After challenge with CII, female mice had higher cellularity and increased T cell proliferation and produced higher levels of proinflammatory cytokines than did the male mice.DRB1*0401.AEo mice developed CIA predominantly in females and produced rheumatoid factors, similar to the features of human RA. Another feature similar to human RA is the expression of class II molecules on antigen-presenting cells as well as T cells. Activated and sorted CD4+ T cells can present DR4-restricted type II collagen (CII)–derived peptide in vitro, but cannot process the antigen. This suggests a role for these cells in epitope presentation locally in joints, which affects disease severity. After challenge with CII, female mice had higher cellularity and increased T cell proliferation and produced higher levels of proinflammatory cytokines than did the male mice.ConclusionDR4.AEo mice expressed HLA similar to humans and displayed increased arthritis susceptibility in females, thus mimicking RA in humans. This model may be valuable for studying sex differences observed in humans and for understanding why autoimmunity is increased in women. These mice may also be useful for developing future therapeutic strategies.DR4.AEo mice expressed HLA similar to humans and displayed increased arthritis susceptibility in females, thus mimicking RA in humans. This model may be valuable for studying sex differences observed in humans and for understanding why autoimmunity is increased in women. These mice may also be useful for developing future therapeutic strategies.
Journal of Autoimmunity, 2011
Population studies have shown that amongst all the genetic factors linked with autoimmune disease... more Population studies have shown that amongst all the genetic factors linked with autoimmune disease development, MHC class II genes are the most significant. Experimental autoimmune arthritis resembling human rheumatoid arthritis (RA) can be induced in susceptible strains of mice following immunization with type II collagen (CIA). We generated transgenic mice lacking endogenous class II molecules and expressing various HLA genes including RA-associated, HLA-DRB1*0401 and HLA-DQ8, and RA-resistant, DRB1*0402, genes. The HLA molecules in these mice are expressed on the cell surface and can positively select CD4+ T cells expressing various Vβ T cell receptors. Endogenous class II invariant chain is required for proper functioning of the class II transgene. Arthritis development in transgenic mice is CD4+ and B cells dependent. Studies in humanized mice showed that B cells are required as antigen presenting cells in addition to antibody producing cells for the development of CIA. The transgenic mice expressing *0401 and *0401/DQ8 genes developed sex-biased arthritis with predominantly females being affected, similar to that of human RA. Further, the transgenic mice produced autoantibodies like rheumatoid factor and anti-cyclic antibodies. Antigen presentation by B cells leads to a sex specific immune response in DRB1*0401 mice suggesting a role of B cells and HLA-DR in rendering susceptibility to develop arthritis in females.
Journal of Autoimmunity, 2010
HLA class II allele DRB1*0401 is associated with predisposition to Rheumatoid Arthritis in humans... more HLA class II allele DRB1*0401 is associated with predisposition to Rheumatoid Arthritis in humans as well as collagen-induced arthritis in mice. Predominantly females develop arthritis in humans and DR4 transgenic mice; however the mechanism of sex-bias is still unknown. We have investigated the molecular basis by which DR4 is associated with sex-bias of arthritis. Here we show that differential antigen-specific immune mechanisms in DR4 male and female mice lead to increased susceptibility in female mice. B cells are hyperactive and present DR-restricted peptides robustly in females compared to males. Antigen-specific response showed that females produced B cell modulating cytokines like IL-13 while males produced IFNγ. Male transgenic mice have higher number of T and B regulatory cells. An exogenous supply of 17β estradiol in male mice led to enhanced expression of DR4 and antigen-specific response to DR4-restricted peptides. On the other hand, castration increased the incidence of arthritis. We propose that sex-bias in arthritis involves B cells and presentation of antigen by HLA-DR4 leading to activation of autoreactive cells and autoantibodies production in females, while regulatory B cells in males protect them from pathogenesis. The transgenic mice expressing RA susceptible haplotype simulate human RA and may be valuable to study gender differences observed in patients.
Journal of Clinical Investigation, 2003