Crystallization and synchrotron X-ray diffraction studies of human interleukin-22

Human interleukin-22, a novel member of the cytokine family, has been crystallized in hanging drops using the vapour-diffusion technique. Preliminary X-ray diffraction experiments using synchrotron radiation reveal that the protein crystallizes in space group P2(1)2(1)2(1), with unit-cell parameters a = 55.44, b = 61.62, c = 73.43 Angstrom, and diffracts beyond 2.00 Angstrom resolution.58352953

Alpha and lambda interferon together mediate suppression of CD4 T cells induced by respiratory syncytial virus

The mechanism by which respiratory syncytial virus (RSV) suppresses T-cell proliferation to itself and other antigens is poorly understood. We used monocyte-derived dendritic cells (MDDC) and CD4 T cells and measured [(3)H]thymidine incorporation to determine the factors responsible for RSV-induced T-cell suppression. These two cell types were sufficient for RSV-induced suppression of T-cell proliferation in response to cytomegalovirus or Staphylococcus enterotoxin B. Suppressive activity was transferable with supernatants from RSV-infected MDDC and was not due to transfer of live virus or RSV F (fusion) protein. Supernatants from RSV-infected MDDC, but not MDDC exposed to UV-killed RSV or mock conditions, contained alpha interferon (IFN-alpha; median, 43 pg/ml) and IFN-lambda (approximately 1 to 20 ng/ml). Neutralization of IFN-alpha with monoclonal antibody (MAb) against one of its receptor chains, IFNAR2, or of IFN-lambda with MAb against either of its receptor chains, IFN-lambdaR1 (interleukin 28R [IL-28R]) or IL-10R2, had a modest effect. In contrast, blocking the two receptors together markedly reduced or completely blocked the RSV-induced suppression of CD4 T-cell proliferation. Defining the mechanism of RSV-induced suppression may guide vaccine design and provide insight into previously uncharacterized human T-cell responses and activities of interferons

IL-22 mediates goblet cell hyperplasia and worm expulsion in intestinal helminth infection.

Type 2 immune responses are essential in protection against intestinal helminth infections. In this study we show that IL-22, a cytokine important in defence against bacterial infections in the intestinal tract, is also a critical mediator of anti-helminth immunity. After infection with Nippostrongylus brasiliensis, a rodent hookworm, IL-22-deficient mice showed impaired worm expulsion despite normal levels of type 2 cytokine production. The impaired worm expulsion correlated with reduced goblet cell hyperplasia and reduced expression of goblet cell markers. We further confirmed our findings in a second nematode model, the murine whipworm Trichuris muris. T.muris infected IL-22-deficient mice had a similar phenotype to that seen in N.brasiliensis infection, with impaired worm expulsion and reduced goblet cell hyperplasia. Ex vivo and in vitro analysis demonstrated that IL-22 is able to directly induce the expression of several goblet cell markers, including mucins. Taken together, our findings reveal that IL-22 plays an important role in goblet cell activation, and thus, a key role in anti-helminth immunity

IL-22 Is Produced by Innate Lymphoid Cells and Limits Inflammation in Allergic Airway Disease

Interleukin (IL)-22 is an effector cytokine, which acts primarily on epithelial cells in the skin, gut, liver and lung. Both pro- and anti-inflammatory properties have been reported for IL-22 depending on the tissue and disease model. In a murine model of allergic airway inflammation, we found that IL-22 is predominantly produced by innate lymphoid cells in the inflamed lungs, rather than TH cells. To determine the impact of IL-22 on airway inflammation, we used allergen-sensitized IL-22-deficient mice and found that they suffer from significantly higher airway hyperreactivity upon airway challenge. IL-22-deficiency led to increased eosinophil infiltration lymphocyte invasion and production of CCL17 (TARC), IL-5 and IL-13 in the lung. Mice treated with IL-22 before antigen challenge displayed reduced expression of CCL17 and IL-13 and significant amelioration of airway constriction and inflammation. We conclude that innate IL-22 limits airway inflammation, tissue damage and clinical decline in allergic lung disease

HHV-6B Induces IFN-Lambda1 Responses in Cord Plasmacytoid Dendritic Cells through TLR9

Human herpesvirus type 6B (HHV-6B) is a strong inducer of IFN-alpha and has the capacity to promote Th1 responses and block Th2 responses in vitro. In this study we addressed whether inactivated HHV-6B can also induce IFN lambda responses and to what extent interferons alpha and lambda affect Th1/Th2 polarization. We show that inactivated HHV-6B induced IFN-lambda1 (IL-29) but not IFN-lambda2 (IL-28A) responses in plasmacytoid DC and that this induction was mediated through TLR9. We have previously shown that HHV-6B promotes Th1 responses and blocks Th2 responses in both humans and mice. We now show that neutralization of IFN-alpha but not IFN-lambda1 blocked the HHV-6B-induced enhancement of Th1 responses in MLR, but did not affect the HHV-6-induced dampening of Th2 responses. Similarly, blockage of TLR9 counteracted HHV-6Bs effects on the Th1/Th2 balance. In addition, IFN-alpha but not IFN-lambda1 promoted IFN-gamma production and blocked IL-5 and IL-13 production in purified CD4+ T-cells. The lack of effect of IFN-lambda1 correlated with the absence of the IFN-lambda receptor IL-28Ralfa chain on the cell surface of both resting and activated CD4+ T-cells. We conclude that inactivated HHV-6B is a strong inducer of IFN-lambda1 in plasmacytoid DC and that this induction is TLR9-dependent. However, human CD4+ T-cells do not express the IFN-lambda receptor and are refractory to IFN-lambda1 treatment. The HHV-6B-induced alterations in the Th1/Th2 balance are instead mediated mainly through TLR9 and IFN-alpha

IFN-Lambda (IFN-λ) Is Expressed in a Tissue-Dependent Fashion and Primarily Acts on Epithelial Cells In Vivo

Interferons (IFN) exert antiviral, immunomodulatory and cytostatic activities. IFN-α/β (type I IFN) and IFN-λ (type III IFN) bind distinct receptors, but regulate similar sets of genes and exhibit strikingly similar biological activities. We analyzed to what extent the IFN-α/β and IFN-λ systems overlap in vivo in terms of expression and response. We observed a certain degree of tissue specificity in the production of IFN-λ. In the brain, IFN-α/β was readily produced after infection with various RNA viruses, whereas expression of IFN-λ was low in this organ. In the liver, virus infection induced the expression of both IFN-α/β and IFN-λ genes. Plasmid electrotransfer-mediated in vivo expression of individual IFN genes allowed the tissue and cell specificities of the responses to systemic IFN-α/β and IFN-λ to be compared. The response to IFN-λ correlated with expression of the α subunit of the IFN-λ receptor (IL-28Rα). The IFN-λ response was prominent in the stomach, intestine and lungs, but very low in the central nervous system and spleen. At the cellular level, the response to IFN-λ in kidney and brain was restricted to epithelial cells. In contrast, the response to IFN-α/β was observed in various cell types in these organs, and was most prominent in endothelial cells. Thus, the IFN-λ system probably evolved to specifically protect epithelia. IFN-λ might contribute to the prevention of viral invasion through skin and mucosal surfaces

High Fat Diet Induces Formation of Spontaneous Liposarcoma in Mouse Adipose Tissue with Overexpression of Interleukin 22

Interleukin 22 (IL-22) is a T-cell secreted cytokine that modulates inflammatory response in nonhematopoietic tissues such as epithelium and liver. The function of IL-22 in adipose tissue is currently unknown. We generated a transgenic mouse model with overexpression of IL-22 specifically in adipose tissue. The IL-22 transgenic mice had no apparent changes in obesity and insulin resistance after feeding with high fat diet (HFD). Unexpectedly, all the IL-22 transgenic mice fed with HFD for four months developed spontaneous tumors in epididymal adipose tissue. Histological analysis indicated that the tumors were well-differentiated liposarcomas with infiltration of inflammatory cells. IL-22 overexpression promotes production of inflammatory cytokines such as IL-1β and IL-10 and stimulates ERK phosphorylation in adipose tissue. Furthermore, IL-22 treatment in differentiated 3T3-L1 adipocytes could induce IL-1β and IL-10 expression, together with stimulation of ERK phosphorylation. Taken together, our study not only established a novel mouse model with spontaneous liposarcoma, but also revealed that IL-22 overexpression may collaborate with diet-induced obesity to impact on tumor development in mouse

Tumour suppressor function of MDA-7/IL-24 in human breast cancer

Introduction Melanoma differentiation associated gene-7 (MDA-7), also known as interleukin (IL)-24, is a tumour suppressor gene associated with differentiation, growth and apoptosis. However, the mechanisms underlying its anti-neoplastic activity, tumour-specificity and efficacy across a spectrum of human cancers have yet to be fully elucidated. In this study, the biological impact of MDA-7 on the behavior of breast cancer (BC) cells is evaluated. Furthermore, mRNA expression of MDA-7 is assessed in a cohort of women with BC and correlated with established pathological parameters and clinical outcome. Methods The human BC cell line MDA MB-231 was used to evaluate the in-vitro impact of recombinant human (rh)-MDA-7 on cell growth and motility, using a growth assay, wounding assay and electric cell impedance sensing (ECIS). Localisation of MDA-7 in mammary tissues was assessed with standard immuno-histochemical methodology. BC tissues (n = 127) and normal tissues (n = 33) underwent RNA extraction and reverse transcription, MDA-7 transcript levels were determined using real-time quantitative PCR. Transcript levels were analyzed against tumour size, grade, oestrogen receptor (ER) status, nodal involvement, TNM stage, Nottingham Prognostic Index (NPI) and clinical outcome over a 10 year follow-up period. Results Exposure to rh-MDA-7 significantly reduced wound closure rates for human BC cells in-vitro. The ECIS model demonstrated a significantly reduced motility and migration following rh-MDA-7 treatment (p = 0.024). Exposure to rh-MDA-7 was only found to exert a marginal effect on growth. Immuno-histochemical staining of human breast tissues revealed substantially greater MDA-7 positivity in normal compared to cancer cells. Significantly lower MDA-7 transcript levels were identified in those predicted to have a poorer prognosis by the NPI (p = 0.049) and those with node positive tumours. Significantly lower expression was also noted in tumours from patients who died of BC compared to those who remained disease free (p = 0.035). Low levels of MDA-7 were significantly correlated with a shorter disease free survival (mean = 121.7 vs. 140.4 months, p = 0.0287) on Kaplan-Meier survival analysis. Conclusion MDA-7 significantly inhibits the motility and migration of human BC cells in-vitro. MDA-7 expression is substantially reduced in malignant breast tissue and low transcript levels are significantly associated with unfavourable pathological parameters, including nodal positivity; and adverse clinical outcomes including poor prognosis and shorter disease free survival. MDA-7 offers utility as a prognostic marker and potential for future therapeutic strategies