Expression, localization, and functional activity of TL1A, a novel Th1-polarizing cytokine in inflammatory bowel disease.
TL1A is a novel TNF-like factor that acts as a costimulator of IFN-gamma secretion through binding to the death domain-containing receptor, DR3. The aim of this study was to test the hypothesis that TL1A may play an important role in inflammatory bowel disease (IBD) by functioning as a Th1-polarizing cytokine. The expression, cellular localization, and functional activity of TL1A and DR3 were studied in intestinal tissue specimens as well as isolated lamina propria mononuclear cells from IBD patients and controls. TL1A mRNA and protein expression was up-regulated in IBD, particularly in involved areas of Crohn's disease (CD; p < 0.03 vs control). TL1A production was localized to the intestinal lamina propria in macrophages and CD4(+) and CD8(+) lymphocytes from CD patients as well as in plasma cells from ulcerative colitis patients. The amount of TL1A protein and the number of TL1A-positive cells correlated with the severity of inflammation, most significantly in CD. Increased numbers of immunoreactive DR3-positive T lymphocytes were detected in the intestinal lamina propria from IBD patients. Addition of recombinant human TL1A to cultures of PHA-stimulated lamina propria mononuclear from CD patients significantly augmented IFN-gamma production by 4-fold, whereas a minimal effect was observed in control patients. Our study provides evidence for the first time that the novel cytokine TL1A may play an important role in a Th1-mediated disease such as CD.
Bamias
Giorgos
G
Digestive Health Center of Excellence, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA.
Martin
Charles
C
Marini
Marco
M
Hoang
Sharon
S
Mishina
Margarita
M
Ross
William G
WG
Sachedina
Muhammadreza A
MA
Friel
Charles M
CM
Mize
James
J
Bickston
Stephen J
SJ
Pizarro
Theresa T
TT
Wei
Ping
P
Cominelli
Fabio
F
D015153:Blotting, Western; D002478:Cells, Cultured; D003424:Crohn Disease / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D007371:Interferon-gamma / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis; D053219:Receptors, Tumor Necrosis Factor, Member 25; D012720:Severity of Illness Index; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism*; D053380:Tumor Necrosis Factor Ligand Superfamily Member 15; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D053219:Receptors, Tumor Necrosis Factor, Member 25; C506033:TNFRSF25 protein, human; C117026:TNFSF15 protein, human; D053380:Tumor Necrosis Factor Ligand Superfamily Member 15; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma