title: Long-term treatment with anti-alpha 4 integrin antibodies aggravates colitis in G alpha i2-deficient mice.
abstract: Targeted deletion of the heterotrimeric G protein, Galphai2, in mice induces lethal colitis closely resembling ulcerative colitis. In chronic colitis, migration of circulating leukocytes into the intestinal mucosa is partially dependent on alpha4 integrins. In previous studies, short-term administration of anti-alpha4 integrin antibodies has been shown to attenuate intestinal inflammation, and here we elucidate the effect of long-term administration of anti-alpha4 integrin antibodies on colitis in Galphai2(-/- )mice. Long-term blockade of alpha4 integrin significantly increased the severity of colitis in Galphai2(-/-) mice. The inflammation was confined to the colon, associated with increased cancer in situ, destruction of crypt architecture, and increased production of IL-1beta, TNF-alpha and IFN-gamma. Blockade of alpha4 integrin reduced the recruitment of activated T cells to the small intestine. In strong contrast, there were significantly higher numbers of activated T cells in the colonic lamina propria and epithelium, most probably due to in situ proliferation. Furthermore, treatment with alpha4 integrin antibodies induced decreased levels of total IgA and IgG in sera, whereas total IgM levels were unchanged. These new findings may have implications in the understanding of the progression of chronic intestinal inflammation.
authors.affiliation: Department of Clinical Immunology, Göteborg University, Gothenburg, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Bjursten
authors.forename: Paul W
authors.initials: PW
authors.lastname: Bland
authors.forename: Roger
authors.initials: R
authors.lastname: Willén
authors.forename: Elisabeth Hultgren
authors.initials: EH
authors.lastname: Hörnquist
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000009:adverse effects* / Q000627:therapeutic use; D000911:Antibodies, Monoclonal / Q000009:adverse effects* / Q000627:therapeutic use; D003092:Colitis / Q000276:immunology* / Q000473:pathology; D003106:Colon / Q000187:drug effects / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000172:deficiency* / Q000235:genetics; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D039441:Integrin alpha4 / Q000276:immunology*; D008221:Lymphoid Tissue / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011518:Proto-Oncogene Proteins / Q000172:deficiency* / Q000235:genetics; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013997:Time Factors
chemical_list: D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011518:Proto-Oncogene Proteins; D039441:Integrin alpha4; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C498016:Gnai2 protein, mouse