Transfection of IL-10 expression vectors into endothelial cultures attenuates α4β7-dependent lymphocyte adhesion mediated by MAdCAM-1

BACKGROUND: Enhanced expression of MAdCAM-1 (mucosal addressin cell adhesion molecule-1) is associated with the onset and progression of inflammatory bowel disease. The clinical significance of elevated MAdCAM-1 expression is supported by studies showing that immunoneutralization of MAdCAM-1, or its ligands reduce inflammation and mucosal damage in models of colitis. Interleukin-10 (IL-10) is an endogenous anti-inflammatory and immunomodulatory cytokine that has been shown to prevent inflammation and injury in several animal studies, however clinical IL-10 treatment remains insufficient because of difficulties in the route of IL-10 administration and its biological half-life. Here, we examined the ability of introducing an IL-10 expression vector into endothelial cultures to reduce responses to a proinflammatory cytokine, TNF-α METHODS: A human IL-10 expression vector was transfected into high endothelial venular ('HEV') cells (SVEC4-10); we then examined TNF-α induced lymphocyte adhesion to lymphatic endothelial cells and TNF-α induced expression of MAdCAM-1 and compared these responses to control monolayers. RESULTS: Transfection of the IL-10 vector into endothelial cultures significantly reduced TNF-α induced, MAdCAM-1 dependent lymphocyte adhesion (compared to non-transfected cells). IL-10 transfected endothelial cells expressed less than half (46 ± 6.6%) of the MAdCAM-1 induced by TNF-α (set as 100%) in non-transfected (control) cells. CONCLUSION: Our results suggest that gene therapy of the gut microvasculature with IL-10 vectors may be useful in the clinical treatment of IBD

Three Month Follow-Up of Patients With COVID-19 Pneumonia Complicated by Pulmonary Embolism

Background: Previous studies have demonstrated persistent dyspnoea and impairment of respiratory function in the follow-up of patients who have recovered from COVID-19 pneumonia. However, no studies have evaluated the clinical and functional consequences of COVID-19 pneumonia complicated by pulmonary embolism. Objective: The aim of our study was to assess the pulmonary function and exercise capacity in COVID-19 patients 3 months after recovery from pneumonia, either complicated or not by pulmonary embolism. Methods: This was a retrospective, single-centre, observational study involving 68 adult COVID-19 patients with a positive/negative clinical history of pulmonary embolism (PE) as a complication of COVID-19 pneumonia. Three months after recovery all patients underwent spirometry, diffusion capacity of the lungs for carbon monoxide (DLCO), and 6 minute walk test (6MWT). In addition, high-resolution computed tomography (HRCT) of the lung was carried out and CT-pulmonary angiography was conducted only in the PE+ subgroup. Patients with a previous diagnosis of PE or chronic lung diseases were excluded from the study. Results: Of the 68 patients included in the study, 24 had previous PE (PE+) and 44 did not (PE-). In comparison with the PE- subgroup, PE+ patients displayed a FVC% predicted significantly lower (87.71 ± 15.40 vs 98.7 ± 16.7, p = 0.009) and a significantly lower DLCO% predicted (p = 0.023). In addition, a higher percentage of patients were dyspnoeic on exercise, as documented by a mMRC score ≥1 (75% vs 54.3%, p < 0.001) and displayed a SpO2 <90% during 6MWT (37.5% vs 0%, p < 0.001). HRCT features suggestive of COVID-19 pneumonia resolution phase were present in both PE+ and PE- subjects without any significant difference (p = 0.24) and abnormalities at CT pulmonary angiography were detected in 57% of the PE+ subgroup. Conclusion: At the 3 month follow-up, the patients who recovered from COVID-19 pneumonia complicated by PE showed more dyspnoea and higher impairment of pulmonary function tests compared with those without PE

Improving the yield of circulating tumour cells facilitates molecular characterisation and recognition of discordant HER2 amplification in breast cancer

BACKGROUND: Circulating tumour cells (CTCs) offer a non-invasive approach to obtain and characterise metastatic tumour cells, but their usefulness has been limited by low CTC yields from conventional isolation methods. METHODS: To improve CTC yields and facilitate their molecular characterisation we compared the Food and Drug Administration-approved CellSearch Epithelial Kit (CEK) to a simplified CTC capture method, CellSearch Profile Kit (CPK), on paired blood samples from patients with metastatic breast (n=75) and lung (n=71) cancer. Molecular markers including Human Epidermal growth factor Receptor 2 (HER2) were evaluated on CTCs by fluorescence in situ hybridisation (FISH) and compared to patients' primary and metastatic cancer. RESULTS: The median cell count from patients with breast cancer using the CPK was 117 vs 4 for CEK (P<0.0001). Lung cancer samples were similar; CPK: 145 cells vs CEK:4 cells (P<0.0001). Recovered CTCs were relatively pure (60-70%) and were evaluable by FISH and immunofluorescence. A total of 10 of 30 (33%) breast cancer patients with HER2-negative primary and metastatic tissue had HER2-amplified CTCs. CONCLUSION: The CPK method provides a high yield of relatively pure CTCs, facilitating their molecular characterisation. Circulating tumour cells obtained using CPK technology demonstrate that significant discordance exists between HER2 amplification of a patient's CTCs and that of the primary and metastatic tumour

Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair

The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway

The MHV68 M2 Protein Drives IL-10 Dependent B Cell Proliferation and Differentiation

Murine gammaherpesvirus 68 (MHV68) establishes long-term latency in memory B cells similar to the human gammaherpesvirus Epstein Barr Virus (EBV). EBV encodes an interleukin-10 (IL-10) homolog and modulates cellular IL-10 expression; however, the role of IL-10 in the establishment and/or maintenance of chronic EBV infection remains unclear. Notably, MHV68 does not encode an IL-10 homolog, but virus infection has been shown to result in elevated serum IL-10 levels in wild-type mice, and IL-10 deficiency results in decreased establishment of virus latency. Here we show that a unique MHV68 latency-associated gene product, the M2 protein, is required for the elevated serum IL-10 levels observed at 2 weeks post-infection. Furthermore, M2 protein expression in primary murine B cells drives high level IL-10 expression along with increased secretion of IL-2, IL-6, and MIP-1α. M2 expression was also shown to significantly augment LPS driven survival and proliferation of primary murine B cells. The latter was dependent on IL-10 expression as demonstrated by the failure of IL10−/− B cells to proliferate in response to M2 protein expression and rescue of M2-associated proliferation by addition of recombinant murine IL-10. M2 protein expression in primary B cells also led to upregulated surface expression of the high affinity IL-2 receptor (CD25) and the activation marker GL7, along with down-regulated surface expression of B220, MHC II, and sIgD. The cells retained CD19 and sIgG expression, suggesting differentiation to a pre-plasma memory B cell phenotype. These observations are consistent with previous analyses of M2-null MHV68 mutants that have suggested a role for the M2 protein in expansion and differentiation of MHV68 latently infected B cells—perhaps facilitating the establishment of virus latency in memory B cells. Thus, while the M2 protein is unique to MHV68, analysis of M2 function has revealed an important role for IL-10 in MHV68 pathogenesis—identifying a strategy that appears to be conserved between at least EBV and MHV68

The role of dendritic cells in driving genital tract inflammation and HIV transmission risk: are there opportunities to intervene?

CAPRISA, 2015.Abstract available in pdf

LPS induces IL-10 production by human alveolar macrophages via MAPKinases- and Sp1-dependent mechanisms

<p>Abstract</p> <p>Background</p> <p>IL-10 is a cytokine mainly produced by macrophages that plays key roles in tolerance to inhaled antigens and in lung homeostasis. Its regulation in alveolar macrophages (HAM), the resident lung phagocytes, remains however unknown.</p> <p>Methods</p> <p>The present study investigated the role of intracellular signalling and transcription factors controlling the production of IL-10 in LPS-activated HAM from normal nonsmoking volunteers.</p> <p>Results</p> <p>LPS (1–1000 pg/ml) induced <it>in vitro </it>IL-10 production by HAM, both at mRNA and protein levels. LPS also activated the phosphorylation of ERK, p38 and JNK MAPkinases (immunoblots) and Sp-1 nuclear activity (EMSA). Selective inhibitors of MAPKinases (respectively PD98059, SB203580 and SP600125) and of Sp-1 signaling (mithramycin) decreased IL-10 expression in HAM. In addition, whilst not affecting IL-10 mRNA degradation, the three MAPKinase inhibitors completely abolished Sp-1 activation by LPS in HAM.</p> <p>Conclusion</p> <p>These results demonstrate for the first time that expression of IL-10 in lung macrophages stimulated by LPS depends on the concomitant activation of ERK, p38 and JNK MAPKinases, which control downstream signalling to Sp-1 transcription factor. This study further points to Sp-1 as a key signalling pathway for IL-10 expression in the lung.</p

Interleukin 10 (IL-10): an immunosuppressive factor and independent predictor in patients with metastatic renal cell carcinoma

Interleukin 10 (IL-10) is an immunosuppressive factor and has been detected in tumour cell cultures of renal cell carcinoma and of malignant melanoma. IL-10 has been described as a cytokine of the Th2 response; it is able to suppress antigen-presenting cells (APCs) and may lead to down-regulation of HLA class I and II molecules on dendritic cells and to anergy of T-lymphocytes. We evaluated pretreatment serum levels of soluble IL-10 and various clinical parameters to determine their prognostic value in 80 advanced renal cell carcinoma patients seen at our institution between May 1990 and April 1996. For statistical evaluation we used both univariate and multivariate Cox proportional hazards models. An elevated pretreatment serum level of IL-10 was a statistically independent predictor of unfavourable outcome (P < 0.0028), in addition to the well-known clinical and biochemical risk factors. These data support risk stratification for future therapeutic trials and identify a predictor which needs to be validated in prospective studies and may potentially influence decision making in palliative management of patients with metastatic renal cell carcinoma. These data also suggest a potential role of IL-10 in the development of advanced renal cell carcinoma and in the future design of therapeutic strategies. © 1999 Cancer Research Campaig