Epithelium derived interleukin 15 regulates intraepithelial lymphocyte Th1 cytokine production, cytotoxicity, and survival in coeliac disease

Background and aims: Epithelium derived interleukin (IL)-15 signalling via IL-15Rα is critical for the development, activation, and survival of intraepithelial lymphocytes (IEL). We aimed to better understand the IL-15 driven effects on IEL underlying mucosal damage and lymphomagenesis in coeliac disease (CD). Methods: Enterocytes, IEL, and lamina propria mononuclear cells (LPMC) were isolated from 46 patients with uncomplicated CD (25 untreated and 21 treated) and 22 controls. IL-15 and IL-15Rα expression were determined by immunoblotting. Secretion of IL-15, interferon γ (IFN-γ), tumour necrosis factor α (TNF-α), and granzyme B into cell culture supernatants was assessed by ELISA. The ability of IL-15 to regulate IEL proliferation, perforin/granzyme dependent cytotoxicity, and apoptosis was tested by adding different combinations of IL-15, IL-15 blocking antibody, or chloroquine to IEL cultured alone or with Caco-2 cells as target. IL-15 mucosal levels were also determined by ELISA in five patients with complicated CD (two ulcerative jejunoileites, one refractory sprue, and two enteropathy associated T cell lymphomas) tested for T cell receptor γ chain clonality. Results: IL-15 was overexpressed in untreated CD enterocytes and LPMC, and in the mucosa of complicated CD patients and uncomplicated untreated CD patients, where its levels correlated with the degree of mucosal damage. Enterocytes from untreated, but not treated, CD patients and controls secreted IL-15. Untreated CD IEL, characterised by higher IL-15Rα expression, showed increased proliferation, production of IFN-γ and TNF-α, and perforin/granzyme dependent cytotoxicity, and a decreased propensity to apoptosis in response to IL-15. Conclusions: Our findings suggest that IL-15 plays a crucial role in the generation of epithelial damage in active CD. Its promotion of IEL survival in CD may predispose to the emergence of T cell clonal proliferations. Blocking IL-15, by suppressing uncontrolled IEL activation and survival, has the potential to provide new therapeutic tools to prevent tissue damage and lymphomagenesis in CD.

[1]  K. Lundin,et al.  Histological changes in small bowel mucosa induced by gliadin sensitive T lymphocytes can be blocked by anti-interferon gamma antibody. , 1995, Gut.

[2]  T. Dassopoulos,et al.  IL-15 receptor maintains lymphoid homeostasis by supporting lymphocyte homing and proliferation. , 1998, Immunity.

[3]  R. Paus,et al.  Interleukin-15 protects from lethal apoptosis in vivo , 1997, Nature Medicine.

[4]  Vahid Asnafi,et al.  Interleukin 15: a key to disrupted intraepithelial lymphocyte homeostasis and lymphomagenesis in celiac disease. , 2003, Gastroenterology.

[5]  J. Miyazaki,et al.  IL-15-Dependent Activation-Induced Cell Death-Resistant Th1 Type CD8αβ+NK1.1+ T Cells for the Development of Small Intestinal Inflammation1 , 2002, The Journal of Immunology.

[6]  M. Zucca,et al.  Human monocytes constitutively express membrane-bound, biologically active, and interferon-gamma-upregulated interleukin-15. , 1999, Blood.

[7]  G. Leclercq,et al.  Differential effects of interleukin-15 and interleukin-2 on differentiation of bipotential T/natural killer progenitor cells , 1996, The Journal of experimental medicine.

[8]  Paul Rutgeerts,et al.  IL-15 Is Highly Expressed in Inflammatory Bowel Disease and Regulates Local T Cell-Dependent Cytokine Production1 , 2000, The Journal of Immunology.

[9]  I. McInnes,et al.  Interleukin-15 mediates T cell-dependent regulation of tumor necrosis factor-α production in rheumatoid arthritis , 1997, Nature Medicine.

[10]  R. Jian,et al.  Selective expansion of intraepithelial lymphocytes expressing the HLA-E–specific natural killer receptor CD94 in celiac disease☆☆☆ , 2000, Gastroenterology.

[11]  J. Schatzle,et al.  Functional Defects of NK Cells Treated with Chloroquine Mimic the Lytic Defects Observed in Perforin-Deficient Mice1 , 2000, The Journal of Immunology.

[12]  Y. Yoshikai,et al.  Interleukin‐15 preferentially promotes the growth of intestinal intraepithelial lymphocytes bearing γδ T cell receptor in mice , 1997 .

[13]  E. Ebert.  Interleukin 15 is a potent stimulant of intraepithelial lymphocytes. , 1998, Gastroenterology.

[14]  P. Isaacson,et al.  Mucosal intra-epithelial lymphocytes in enteropathy-associated T-cell lymphoma, ulcerative jejunitis, and refractory celiac disease constitute a neoplastic population. , 1999, Blood.

[15]  L. Maiuri,et al.  Interleukin 15 mediates epithelial changes in celiac disease. , 2000, Gastroenterology.

[16]  S. Fukuyama,et al.  Autocrine IL-15 Mediates Intestinal Epithelial Cell Death Via the Activation of Neighboring Intraepithelial NK Cells1 , 2002, The Journal of Immunology.

[17]  Y. Yoshikai,et al.  Interleukin 15 activity in the rectal mucosa of inflammatory bowel disease. , 1998, Gastroenterology.

[18]  A. Abbas,et al.  Homeostasis and self-tolerance in the immune system: turning lymphocytes off. , 1998, Science.

[19]  S. Riddell,et al.  Costimulation of CD8alphabeta T cells by NKG2D via engagement by MIC induced on virus-infected cells. , 2001, Nature immunology.

[20]  J. Sloane,et al.  A Simplified Method of Detection of Clonal Rearrangements of the T‐Cell Receptor-γ Chain Gene , 1992 .

[21]  T. Strom,et al.  Fibroblast-Like Synoviocytes from Rheumatoid Arthritis Patients Express Functional IL-15 Receptor Complex: Endogenous IL-15 in Autocrine Fashion Enhances Cell Proliferation and Expression of Bcl-xL and Bcl-21 , 2002, The Journal of Immunology.

[22]  Govind Bhagat,et al.  Coordinated induction by IL15 of a TCR-independent NKG2D signaling pathway converts CTL into lymphokine-activated killer cells in celiac disease. , 2004, Immunity.

[23]  P. Morrissey,et al.  Reversible Defects in Natural Killer and Memory Cd8 T Cell Lineages in Interleukin 15–Deficient Mice , 2000, The Journal of experimental medicine.

[24]  R. Winchester,et al.  TCR specificity dictates CD94/NKG2A expression by human CTL. , 2002, Immunity.

[25]  木下 直俊.  Autocrine IL-15 mediates intestinal epithelial cell death via the activation of neighboring intraepithelial NK cells , 2003 .

[26]  R. Macdermott,et al.  Intestinal epithelial cells both express and respond to interleukin 15. , 1996, Gastroenterology.

[27]  Seiamak Bahram,et al.  A direct role for NKG2D/MICA interaction in villous atrophy during celiac disease. , 2004, Immunity.

[28]  S. Bauer,et al.  Recognition of stress-induced MHC molecules by intestinal epithelial gammadelta T cells. , 1998, Science.

[29]  S. Riddell,et al.  Costimulation of CD8αβ T cells by NKG2D via engagement by MIC induced on virus-infected cells , 2001, Nature Immunology.

[30]  S. Melgar,et al.  Paradoxical coexpression of proinflammatory and down-regulatory cytokines in intestinal T cells in childhood celiac disease. , 2002, Gastroenterology.

[31]  C. Doglioni,et al.  Cytolytic mechanisms of intraepithelial lymphocytes in coeliac disease (CoD) , 2000, Clinical and experimental immunology.

[32]  T. Waldmann,et al.  IL-15: a pleiotropic cytokine with diverse receptor/signaling pathways whose expression is controlled at multiple levels. , 1996, Immunity.

[33]  N. Copeland,et al.  Functional Characterization of the Human Interleukin-15 Receptor αChain and Close Linkage of IL15RA and IL2RA Genes (*) , 1995, The Journal of Biological Chemistry.

[34]  G. Corazza,et al.  Intraepithelial and lamina propria lymphocytes show distinct patterns of apoptosis whereas both populations are active in Fas based cytotoxicity in coeliac disease , 2001, Gut.

[35]  R. Zambello,et al.  Role of IL-15, IL-2, and their receptors in the development of T cell alveolitis in pulmonary sarcoidosis. , 1996, Journal of immunology.

[36]  J. Sloane,et al.  A simplified method of detection of clonal rearrangements of the T-cell receptor-gamma chain gene. , 1992, Diagnostic molecular pathology : the American journal of surgical pathology, part B.

[37]  Shih-Shun Chen,et al.  Differential Effects of IL-2 and IL-15 on the Death and Survival of Activated TCRγδ+ Intestinal Intraepithelial Lymphocytes , 1999, The Journal of Immunology.

[38]  D. Schuppan,et al.  Matrix metalloproteinase pattern in celiac duodenal mucosa , 2005, Laboratory Investigation.

[39]  M. Dunnill,et al.  A method for the quantitation of small intestinal biopsy specimens , 1972, Journal of clinical pathology.

[40]  G. Corazza,et al.  Quantitative assessment of the mucosal architecture of jejunal biopsy specimens: a comparison between linear measurement, stereology, and computer aided microscopy. , 1985, Journal of clinical pathology.

[41]  D. Reintgen,et al.  Interleukin 15 induction of lymphokine-activated killer cell function against autologous tumor cells in melanoma patient lymphocytes by a CD18-dependent, perforin-related mechanism. , 1995, Cancer research.