Gliadin induces neutrophil migration via engagement of the formyl peptide receptor, FPR1

Background Gliadin, the immunogenic component within gluten and trigger of celiac disease, is known to induce the production of Interleukin-8, a potent neutrophil-Activating and chemoattractant chemokine.We sought to study the involvement of neutrophils in the early immunological changes following gliadin exposure. Methods Utilizing immunofluorescence microscopy and flow cytometry, the redistribution of major tight junction protein, Zonula occludens (ZO)-1, and neutrophil recruitment were assessed in duodenal tissues of gliadin-gavaged C57BL/6 wild-Type and Lys-GFP reporter mice, respectively. Intravital microscopy with Lys-GFP mice allowed monitoring of neutrophil recruitment in response to luminal gliadin exposure in real time. In vitro chemotaxis assays were used to study murine and human neutrophil chemotaxis to gliadin, synthetic alpha-gliadin peptides and the neutrophil chemoattractant, fMet-Leu-Phe, in the presence or absence of a specific inhibitor of the fMet-Leu-Phe receptor-1 (FPR1), cyclosporine H. An irrelevant protein, zein, served as a control. Results Redistribution of ZO-1 and an influx of CD11b+Lys6G+ cells in the lamina propria of the small intestine were observed upon oral gavage of gliadin. In vivo intravital microscopy revealed a slowing down of GFP+ cells within the vessels and influx in the mucosal tissue within 2 hours after challenge. In vitro chemotaxis assays showed that gliadin strongly induced neutrophil migration, similar to fMet-Leu-Phe.We identified thirteen synthetic gliadin peptide motifs that induced cell migration. Blocking of FPR1 completely abrogated the fMet-Leu-Phe-, gliadin- and synthetic peptide-induced migration. Conclusions Gliadin possesses neutrophil chemoattractant properties similar to the classical neutrophil chemoattractant, fMet-Leu-Phe, and likewise uses FPR1 in the process. Copyright

Half-life measurement of 44Sc and 44mSc.

The half-lives of 44Sc and 44mSc were measured by following their decay rate using several measurement systems: two ionization chambers and three γ-spectrometry detectors with digital and/or analogue electronics. For 44Sc, the result was the combination of seven half-life values giving a result of 4.042(7) h, which agrees with the last reported value of 4.042(3) h and confirms the near to 2% deviation from the recommended half-life of 3.97(4) h. Scandium-44 is present as an impurity in the production of 44Sc by cyclotron proton irradiation. Its half-life was determined by measurements performed a few days after End of Bomardment (EoB), so that the 44Sc decayed down to a negligible level. Seven measurements were combined to obtain an average of 58.7(3) h, which is in agreement with the recommended value of 58.6(1) h

Probiotic-based vaccines may provide effective protection against covid-19 acute respiratory disease

Severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) infection, the causative agent of COVID-19, now represents the sixth Public Health Emergency of International Concern (PHEIC)�as declared by the World Health Organization (WHO) since 2009. Considering that SARS-CoV-2 is mainly transmitted via the mucosal route, a therapy administered by this same route may represent a desirable approach to fight SARS-CoV-2 infection. It is now widely accepted that genetically modified microorganisms, including probiotics, represent attractive vehicles for oral or nasal mucosal delivery of therapeutic molecules. Previous studies have shown that the mucosal administration of therapeutic molecules is able to induce an immune response mediated by specific serum IgG and mucosal IgA antibodies along with mucosal cell-mediated immune responses, which effectively concur to neutralize and eradicate infections. Therefore, advances in the modulation of mucosal immune responses, and in particular the use of probiotics as live delivery vectors, may encourage prospective studies to assess the effectiveness of genetically modified probiotics for SARS-CoV-2 infection. Emerging trends in the ever-progressing field of vaccine development re-emphasize the contribution of adjuvants, along with optimization of codon usage (when designing a synthetic gene), expression level, and inoculation dose to elicit specific and potent protective immune re-sponses. In this review, we will highlight the existing pre-clinical and clinical information on the use of genetically modified microorganisms in control strategies against respiratory and non-respiratory viruses. In addition, we will discuss some controversial aspects of the use of genetically modified probiotics in modulating the cross-talk between mucosal delivery of therapeutics and immune system modulation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Selective accumulation of langerhans-type dendritic cells in small airways of patients with COPD

<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DC) linking innate and adaptive immune responses are present in human lungs, but the characterization of different subsets and their role in COPD pathogenesis remain to be elucidated. The aim of this study is to characterize and quantify pulmonary myeloid DC subsets in small airways of current and ex-smokers with or without COPD.</p> <p>Methods</p> <p>Myeloid DC were characterized using flowcytometry on single cell suspensions of digested human lung tissue. Immunohistochemical staining for langerin, BDCA-1, CD1a and DC-SIGN was performed on surgical resection specimens from 85 patients. Expression of factors inducing Langerhans-type DC (LDC) differentiation was evaluated by RT-PCR on total lung RNA.</p> <p>Results</p> <p>Two segregated subsets of tissue resident pulmonary myeloid DC were identified in single cell suspensions by flowcytometry: the langerin+ LDC and the DC-SIGN+ interstitial-type DC (intDC). LDC partially expressed the markers CD1a and BDCA-1, which are also present on their known blood precursors. In contrast, intDC did not express langerin, CD1a or BDCA-1, but were more closely related to monocytes.</p> <p>Quantification of DC in the small airways by immunohistochemistry revealed a higher number of LDC in current smokers without COPD and in COPD patients compared to never smokers and ex-smokers without COPD. Importantly, there was no difference in the number of LDC between current and ex-smoking COPD patients.</p> <p>In contrast, the number of intDC did not differ between study groups. Interestingly, the number of BDCA-1+ DC was significantly lower in COPD patients compared to never smokers and further decreased with the severity of the disease. In addition, the accumulation of LDC in the small airways significantly correlated with the expression of the LDC inducing differentiation factor activin-A.</p> <p>Conclusions</p> <p>Myeloid DC differentiation is altered in small airways of current smokers and COPD patients resulting in a selective accumulation of the LDC subset which correlates with the pulmonary expression of the LDC-inducing differentiation factor activin-A. This study identified the LDC subset as an interesting focus for future research in COPD pathogenesis.</p

Role of the tachykinin NK1 receptor in a murine model of cigarette smoke-induced pulmonary inflammation

<p>Abstract</p> <p>Background</p> <p>The tachykinins, substance P and neurokinin A, present in sensory nerves and inflammatory cells such as macrophages and dendritic cells, are considered as pro-inflammatory agents. Inflammation of the airways and lung parenchyma plays a major role in the pathogenesis of chronic obstructive pulmonary disease (COPD) and increased tachykinin levels are recovered from the airways of COPD patients. The aim of our study was to clarify the involvement of the tachykinin NK₁receptor, the preferential receptor for substance P, in cigarette smoke (CS)-induced pulmonary inflammation and emphysema in a mouse model of COPD.</p> <p>Methods</p> <p>Tachykinin NK₁receptor knockout (NK₁-R^-/-) mice and their wild type controls (all in a mixed 129/sv-C57BL/6 background) were subjected to sub acute (4 weeks) or chronic (24 weeks) exposure to air or CS. 24 hours after the last exposure, pulmonary inflammation and development of emphysema were evaluated.</p> <p>Results</p> <p>Sub acute and chronic exposure to CS resulted in a substantial accumulation of inflammatory cells in the airways of both WT and NK₁-R^-/-mice. However, the CS-induced increase in macrophages and dendritic cells was significantly impaired in NK₁-R^-/-mice, compared to WT controls, and correlated with an attenuated release of MIP-3α/CCL20 and TGF-β1. Chronic exposure to CS resulted in development of pulmonary emphysema in WT mice. NK₁-R^-/-mice showed already enlarged airspaces upon air-exposure. Upon CS-exposure, the NK₁-R^-/-mice did not develop additional destruction of the lung parenchyma. Moreover, an impaired production of MMP-12 by alveolar macrophages upon CS-exposure was observed in these KO mice. In a pharmacological validation experiment using the NK₁receptor antagonist RP 67580, we confirmed the protective effect of absence of the NK₁receptor on CS-induced pulmonary inflammation.</p> <p>Conclusion</p> <p>These data suggest that the tachykinin NK₁receptor is involved in the accumulation of macrophages and dendritic cells in the airways upon CS-exposure and in the development of smoking-induced emphysema. As both inflammation of the airways and parenchymal destruction are important characteristics of COPD, these findings may have implications in the future treatment of this devastating disease.</p

Downregulation of the AU-Rich RNA-Binding Protein ZFP36 in Chronic HBV Patients: Implications for Anti-Inflammatory Therapy

Inflammation caused by chronic hepatitis B virus (HBV) infection is associated with the development of cirrhosis and hepatocellular carcinoma; however, the mechanisms by which HBV infection induces inflammation and inflammatory cytokine production remain largely unknown. We analyzed the gene expression patterns of lymphocytes from chronic HBV-infected patients and found that the expression of ZFP36, an AU-rich element (ARE)-binding protein, was dramatically reduced in CD4+ and CD8+ T lymphocytes from chronic HBV patients. ZFP36 expression was also reduced in CD14+ monocytes and in total PBMCs from chronic HBV patients. To investigate the functional consequences of reduced ZFP36 expression, we knocked down ZFP36 in PBMCs from healthy donors using siRNA. siRNA-mediated silencing of ZFP36 resulted in dramatically increased expression of multiple inflammatory cytokines, most of which were also increased in the plasma of chronic HBV patients. Furthermore, we found that IL-8 and RANTES induced ZFP36 downregulation, and this effect was mediated through protein kinase C. Importantly, we found that HBsAg stimulated PBMCs to express IL-8 and RANTES, resulting in decreased ZFP36 expression. Our results suggest that an inflammatory feedback loop involving HBsAg, ZFP36, and inflammatory cytokines may play a critical role in the pathogenesis of chronic HBV and further indicate that ZFP36 may be an important target for anti-inflammatory therapy during chronic HBV infection

The RNA binding protein HuR differentially regulates unique subsets of mRNAs in estrogen receptor negative and estrogen receptor positive breast cancer

<p>Abstract</p> <p>Background</p> <p>The discordance between steady-state levels of mRNAs and protein has been attributed to posttranscriptional control mechanisms affecting mRNA stability and translation. Traditional methods of genome wide microarray analysis, profiling steady-state levels of mRNA, may miss important mRNA targets owing to significant posttranscriptional gene regulation by RNA binding proteins (RBPs).</p> <p>Methods</p> <p>The ribonomic approach, utilizing RNA immunoprecipitation hybridized to microarray (RIP-Chip), provides global identification of putative endogenous mRNA targets of different RBPs. HuR is an RBP that binds to the AU-rich elements (ARE) of labile mRNAs, such as proto-oncogenes, facilitating their translation into protein. HuR has been shown to play a role in cancer progression and elevated levels of cytoplasmic HuR directly correlate with increased invasiveness and poor prognosis for many cancers, including those of the breast. HuR has been described to control genes in several of the acquired capabilities of cancer and has been hypothesized to be a tumor-maintenance gene, allowing for cancers to proliferate once they are established.</p> <p>Results</p> <p>We used HuR RIP-Chip as a comprehensive and systematic method to survey breast cancer target genes in both MCF-7 (estrogen receptor positive, ER+) and MDA-MB-231 (estrogen receptor negative, ER-) breast cancer cell lines. We identified unique subsets of HuR-associated mRNAs found individually or in both cell types. Two novel HuR targets, <it>CD9 </it>and <it>CALM2 </it>mRNAs, were identified and validated by quantitative RT-PCR and biotin pull-down analysis.</p> <p>Conclusion</p> <p>This is the first report of a side-by-side genome-wide comparison of HuR-associated targets in wild type ER+ and ER- breast cancer. We found distinct, differentially expressed subsets of cancer related genes in ER+ and ER- breast cancer cell lines, and noted that the differential regulation of two cancer-related genes by HuR was contingent upon the cellular environment.</p