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Plasmacytoid dendritic cells (pDCs) are the key producers of type I interferons (IFNs), thus playing a central role in initiating antiviral immune response. Besides robust type I IFN production, pDCs also act as antigen presenting cells post immunogenic stimulation. Transcription factor Irf8 is indispensable for the development of both pDC and cDC1 subset. However, the mechanism underlying the differential regulation by IRF8 in cDC1- and pDC-specific genomic architecture of developmental pathways still remains to be fully elucidated. Previous studies indicated that the Irf8R294C mutation specifically abrogates development of cDC1 without affecting that of pDC. In the present study using RNA-seq based approach, we have found that though the point mutation Irf8R294C did not affect pDC development, it led to defective type I IFN production, thus resulting in inefficient antiviral response. This observation unraveled the distinctive roles of IRF8 in these two subpopulations—regulating the development of cDC1 whereas modulating the functionality of pDCs without affecting development. We have reported here that Irf8R294C mutation also caused defect in production of ISGs as well as defective upregulation of costimulatory molecules in pDCs in response to NDV infection (or CpG stimulation). Through in vivo studies, we demonstrated that abrogation of type I IFN production was concomitant with reduced upregulation of costimulatory molecules in pDCs and increased NDV burden in IRF8R294C mice in comparison with wild type, indicating inefficient viral clearance. Further, we have also shown that Irf8R294C mutation abolished the activation of type I IFN promoter by IRF8, justifying the low level of type I IFN production. Taken together, our study signifies that the single point mutation in Irf8 , Irf8R294C severely compromised type I IFN-mediated immune response by murine pDCs, thereby causing impairment in antiviral immunity. [ABSTRACT FROM AUTHOR]

Dendritic cells (DCs) are a collection of different subtypes, each of which is characterized by specific surface markers, gene-expression patterns, and distinct functions. Members of the IFN regulatory factor family play critical roles in DC development and functions. Recently, Irf8 was shown to activate TGF-b signaling, which led to exacerbated neuroinflammation in the experimental autoimmune encephalomyelitis mouse model. We analyzed the effect of Irf8 on TGF-β/bone morphogenetic protein pathway-specific genes in DCs and identified Acvrl1, a type I TGF-β superfamily receptor, as a gene strongly induced by Irf8 expression. Among various DC subtypes, Acvrl1 is differentially expressed in CD8β+ DCs. ACVRL1 signaling augmented Irf8-directed classical CD8α+ DC development. Irf8 expression is essential for plasmacytoid DC and CD8α+ DC development, and this study demonstrates that ACVRL1 signaling plays a pivotal role whereby it suppresses plasmacytoid DC development while enhancing that of CD8α+ DCs, thus contributing to DC diversity development. [ABSTRACT FROM AUTHOR]

In low and middle-income countries, access to cancer diagnosis and treatment is suboptimal. Further, compliance to cancer treatment is a major issue due to various reasons including financial barriers, lack of family support and fear of treatment. This article discusses the determinants of treatment completion in cancer patients of a government-run hospital, in a rural part of Punjab in India. The Sangrur hospital-based cancer registry data for the year 2018 have been used. We have registered 2,969 cancer cases, out of which 2,528 (85%) cases were eligible for the analysis. Of the total 2,528 cases, 1,362 (54%) cases completed the cancer directed treatment and 1,166 (46%) did not. The data have been collected from the electronic medical record (EMR) department and entered into CanReg5 software. The bivariate and multivariate binary logistic regression analysis was performed to see the effect of variables on the treatment completion. The results indicate that the elderly age group (>60 years) (odds ratio (OR): 0.52, (95% confidence interval (CI): 0.31-0.86)), distance from hospital (OR: 0.67, (95% CI: 0.50-0.89)) and access to government health schemes (OR: 0.13, (95% CI: 0.10-0.19)] have direct correlation with the treatment completion. The educated patients (OR: 1.49, (95% CI: 1.13-1.96)) and patients who received curative treatment (OR: 2.7, (95% CI: 1.88-3.88)) have shown 58% and 84% compliance to treatment completion, respectively. The other variables like the clinical extent of disease, religion, gender and income do not have any significant effect on the treatment completion. Determinants like age (young), education, distance from the hospital, curative treatment and availability of government health schemes for financial support have shown positive effects on treatment completion. These factors have to be considered by the cancer hospitals, health departments and policymakers while planning for cancer care or control in India. [ABSTRACT FROM AUTHOR]

Tuberculosis is the leading cause of death due to an infectious disease worldwide. Innate lymphoid type 3 cells (ILC3s) mediate early protection during Mycobacterium tuberculosis ( Mtb ) infection. However, the early signaling mechanisms that govern ILC3 activation or recruitment within the lung during Mtb infection are unclear. scRNA-seq analysis of Mtb -infected mouse lung innate lymphoid cells (ILCs) has revealed the presence of different clusters of ILC populations, suggesting heterogeneity. Using mouse models, we show that during Mtb infection, interleukin-1 receptor (IL-1R) signaling on epithelial cells drives ILC3 expansion and regulates ILC3 accumulation in the lung. Furthermore, our data revealed that C-X-C motif chemokine receptor 5 (CXCR5) signaling plays a crucial role in ILC3 recruitment from periphery during Mtb infection. Our study thus establishes the early responses that drive ILC3 accumulation during Mtb infection and points to ILC3s as a potential vaccine target., Importance: Tuberculosis is a leading cause of death due to a single infectious agent accounting for 1.6 million deaths each year. In our study, we determined the role of type 3 innate lymphoid cells in early immune events necessary for achieving protection during Mtb infection. Our study reveals distinct clusters of ILC2, ILC3, and ILC3/ILC1-like cells in Mtb infection. Moreover, our study reveal that IL-1R signaling on lung type 2 epithelial cells plays a key role in lung ILC3 accumulation during Mtb infection. CXCR5 on ILC3s is involved in ILC3 homing from periphery during Mtb infection. Thus, our study provides novel insights into the early immune mechanisms governed by innate lymphoid cells that can be targeted for potential vaccine-induced protection., Competing Interests: The authors declare no conflict of interest.

Plasmacytoid dendritic cells (pDCs) are the key producers of type I interferons (IFNs), thus playing a central role in initiating antiviral immune response. Besides robust type I IFN production, pDCs also act as antigen presenting cells post immunogenic stimulation. Transcription factor Irf8 is indispensable for the development of both pDC and cDC1 subset. However, the mechanism underlying the differential regulation by IRF8 in cDC1- and pDC-specific genomic architecture of developmental pathways still remains to be fully elucidated. Previous studies indicated that the Irf8 R294 C mutation specifically abrogates development of cDC1 without affecting that of pDC. In the present study using RNA-seq based approach, we have found that though the point mutation Irf8 R294 C did not affect pDC development, it led to defective type I IFN production, thus resulting in inefficient antiviral response. This observation unraveled the distinctive roles of IRF8 in these two subpopulations-regulating the development of cDC1 whereas modulating the functionality of pDCs without affecting development. We have reported here that Irf8 R294 C mutation also caused defect in production of ISGs as well as defective upregulation of costimulatory molecules in pDCs in response to NDV infection (or CpG stimulation). Through in vivo studies, we demonstrated that abrogation of type I IFN production was concomitant with reduced upregulation of costimulatory molecules in pDCs and increased NDV burden in IRF8 R294C mice in comparison with wild type, indicating inefficient viral clearance. Further, we have also shown that Irf8 R294 C mutation abolished the activation of type I IFN promoter by IRF8, justifying the low level of type I IFN production. Taken together, our study signifies that the single point mutation in Irf8 , Irf8 R294 C severely compromised type I IFN-mediated immune response by murine pDCs, thereby causing impairment in antiviral immunity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Das, Chauhan, Kumar and Tailor.)