bluuebunny/crossref_metadata_2025_split huggingface dataset:
TSLP and IL-33 distinctively modulate the allergic response by differentially modulating Th2 cells and ILC2s
Authors: Gurram Rama Krishna , Zhu Jinfang (Jeff) , Leonard Warren J 
Published: January 2023

Abstract
Alarmins are endogenous chemotactic or immune-activating proteins released after cell injury or immune activation, and these include thymic stromal lymphopoietin (TSLP) and IL-33. Mice lacking these cytokines exhibit defective type 2 responses, but there is controversy regarding the roles of these cytokines in allergic responses in vivo. Here, we demonstrate that the nature of the allergic response is dictated by the alarmin. Mice lacking IL-33 were resistant to pulmonary inflammation induced by papain, but they exhibited normal OVA-induced allergic inflammation. In contrast, mice lacking either TSLP or TSLPR had significantly lower pulmonary inflammation in response to OVA challenge but responded normally to papain. Moreover, while intranasal papain challenge rapidly induced the release of IL-33, OVA challenge predominantly released TSLP. Steady-state pulmonary ILC2s were activated in response to IL-33, and correspondingly, Il33 KO mice showed a similar defect in effector Th2 generation to that observed in animals lacking ILC2s. In contrast to IL-33, TSLP did not activate steady-state ILC2s. Instead, conditional deletion of TSLPR in T cells hampered Th2 cell generation in the OVA-induced asthma model, but these mice responded normally to papain. These data demonstrate that Th2 cells rely on IL-33-stimulated ILC2s, whereas in the OVA-induced asthma model, TSLP acts on Th2 cells to promote type 2 responses. Thus, TSLP and IL-33 are both alarmins, but they have distinctive effects on allergic responses based on their different release kinetics and on their differential actions on Th2 cells versus ILC2s. These findings indicate approaches to selectively target different allergic responses, with potential translational impact.
This research was supported by the Intramural Research Programs of NIAID and NHLBI, NIH.
LMAN1, a Negative Regulator of the Response to House Dust Mite
Authors: Tigno-Aranjuez Justine , Miller Madelyn , Swaby Lindsay , LaFratta Maggie , Zhang Bin 
Published: January 2023

Abstract
We have utilized an unbiased receptor capture approach (CaptiRec) to screen for receptors on dendritic cells which directly bind HDM. Using this technique, we have identified LMAN1 (Lectin, Mannose Binding 1) as a candidate receptor for HDM. LMAN1 is a mannose binding lectin which is primarily known to act as a cargo transporter between the ER, ERGIC, and Golgi compartments. The role played by LMAN1 in the recognition of and response to HDM, is currently unknown. We verify the ability of LMAN1 to directly bind HDM proteins biochemically and in a cellular context. Furthermore, we present evidence to demonstrate that LMAN1 downregulates NF-κB responses in response to inflammatory cytokines and to HDM. Loss of LMAN1 on DCs used for allergic sensitization leads to exacerbated airway inflammation in a HDM model of allergic asthma. Lastly, peripheral DCs of asthmatics show a significant reduction in expression of LMAN1 compared to healthy controls. These findings have potential implications for the development of novel therapeutic interventions for allergy and allergic asthma.
Supported by American Lung Association Innovation Award IA-695632
Sexual dimorphism in the antigen-specific T cell response in S. Typhimurium infections within extra-lymphoid tissues
Authors: D’Souza Shaina J , Immethun Vicki , Godwin Matthew , McLachlan James B 
Published: January 2023

Abstract
Differences in susceptibility to and severity of infectious diseases between the sexes are well established. Females often generate a beneficially stronger immune response when combatting infection but show an increased risk of developing autoimmunity. While the sex-related hormone estradiol is known to affect CD4 T cell cytokine release in vitro, less is known about T cells behavior in vivo. To address this, we intravenously infected male and female mice with attenuated Salmonella Typhimurium (S. Tm). By day 15 post infection (p.i.), male mice showed significantly lower rates of survival. Males also generated a higher number of S. Tm-specific CD4 T cells in the liver but, conversely, displayed higher bacterial burdens. To isolate the role of sex hormones, mice were gonadectomized before reaching sexual maturity and then infected. Ovariectomized mice lost significantly more weight than ovary-intact females by day 15 p.i. Like normal males, ovariectomized females demonstrated a significantly higher number of S. Tm-specific CD4 T cells but also higher liver bacterial burdens. To investigate the role of extra-lymphoid tissues such as the liver, we infected lymphotoxin-alpha (LTa) mice that genetically lack lymphoid tissues. Surprisingly, we found the stark difference in survival and CD4 T cell expansion between the sexes was lost. These differences in T cell expansion, and the commensurate effect on survival, in the presence or absence of endogenous sex hormones or lymphoid tissues indicate that females may have evolved a separate ability to regulate immune responses outside of traditional lymphoid organs. These studies will provide insights into sex-based differences seen in cellular immunity against bacterial pathogens in vivo.
Supported by a grant from the Keck Foundation
Mycobacterium tuberculosis reduces global histone acetylation in human macrophages which is restored by Sirtuin inhibitors
Authors: Jagannath Chinnaswamy , Singh Vipul , Mishra Abhishek , Khan Arshad , Zhang Kangling 
Published: January 2023

Abstract
Mycobacterium tuberculosis (Mtb) infects and grows in human macrophages unless they are activated earlier using IFN-γ. IFN-γ polarized M1-Macrophages (MΦs) and IL-4 driven M2-MΦs respectively kill Mtb or are permissive. Mtb infected M1-MΦs showed an increased expression of iNOS and autophagy-regulating ATGs compared to M2-MΦs. Despite increased bactericidal function, M1-MΦs were unable to eradicate Mtb.

Hypothesis
Because M1- and M2-MΦs differentially expressed Sirtuin1, 2, 3 and Sirt5, we hypothesized that, Sirtuin-dependent histone deacetylation would affect gene expression and bactericidal function

Methods
M0 (naive), M1 or M2-MΦs were treated with inhibitors of Sirtuin1, Sirt2, Sirt3 and Sirt5 followed by Mtb infection, and evaluation of histone modifications using a novel triomics approach. Viability of Mtb was measured before and after Sirtuin blockade and correlated to mRNA expression for iNOS and ATG5 using qPCR.

Results
a) Relative to uninfected M0-MΦs, M1-MΦs showed higher levels of histone acetylation followed by M2-MΦs. b) Mtb infection reduced global histone acetylation in all three MΦ phenotypes, with an concurrent increase in histone methylation. c) Blockade of Sirt1, 2, 3 but not Sirt5 led to a dramatic restoration of histone acetylation in all three phenotypes, although M2-MΦs were still resistant to Sirt3 inhibitors. d) M0, M1- and M2-MΦs killed Mtb more effectively after Sirt2 blockade compared to Sirt1, 3 and 5 inhibition, which was associated with an increase in mRNA for iNOS and ATG5.

Conclusion
We conclude that Mtb decreases histone acetylome of human MΦs and Sirtuin inhibitors provide a new epigenetic mechanism to restore macrophage bactericidal function against tuberculosis.
Supported by NIH NIAID RO1 AI-122070 and AI-161015.
Core fucosylation of N-linked glycans: a novel player in memory CD8+ T cell differentiation following acute viral infection
Authors: Abdelbary Mahmoud , Harbour Jake , Fancher Samantha , Nappi Taylen , Nolz Jeffrey C 
Published: January 2023

Abstract
Core fucosylation (CF) of N-linked glycans is indispensable for normal physiology, but whether CF regulates any aspect of T cell activation, differentiation, or function remains unknown. Fucosyltransferase 8 (Fut8) is the only enzyme in mammals that catalyzes CF and following activation, both expression of Fut8 and CF synthesis increases on CD8+ T cells. To test the hypothesis that CF of N-glycans regulates memory T cell differentiation following acute viral infection, we generated mice with a floxed Fut8 gene. WT (CD4-Cre−) and Fut8−/− (CD4-Cre+) mice were infected with LCMV Armstrong (LCMV-Arm) and the differentiation of LCMV-specific CD8+ T cells was analyzed by measuring the surface expression of killer-cell lectin like receptor G1 (KLRG1) and the α chain of interleukin 7 receptor (CD127) to identify short-lived effector and memory precursor T cells, respectively. LCMV-specific CD8+ T cells from both WT and Fut8−/− followed the same pattern of expansion and contraction without any significant difference in the overall frequency of LCMV-specific CD8+ T cells. However, Fut8−/− retained a higher percentage of CD127+ KLRG1− and a lower percentage of KLRG1+ CD127− CD8 T cells throughout the course of infection suggesting CF influences the progression to long-term memory. At day 42 post infection, mice were infected with virulent Listeria monocytogenes expressing the LCMV epitope GP33–41. Both WT and Fut8−/− GP33-specific CD8+ T cells expanded equally. However, Fut8−/− retained a higher frequency of GP33-specific CD8+ T cells and did not undergo contraction until &gt;3 weeks post-2ry challenge. Taken together, our findings suggest that CF of N-linked glycans regulates memory CD8+ T cell differentiation following acute viral infection.
Supported by grants from NIH (R21 AI159401)
Tim-3 deletion on Treg increases virus-specific T cell response and reduces viral burden in chronic LCMV infection
Authors: Nieves-Rosado Hector M , Banerjee Hridesh , Kane Lawrence P 
Published: January 2023

Abstract
Tim-3, a surface protein, is upregulated on Treg during chronic viral infections. During HCV infection in humans there is an increase in frequency of Tim-3+ Treg, which have increased proliferation, survival, and expression of immunosuppressive cytokines like IL-10. Similarly, it’s been recently reported that there is an increase in Tim-3+ Treg in people with HIV (PWH). However, the role of regulatory T cells (Treg) during chronic viral infection has not been fully defined. We hypothesize that Tim-3 promotes an effector phenotype on Treg during chronic viral infection, which limits the virus-specific T cell response and impairs viral clearance. Using an inducible Treg-specific Tim-3 loss-of-function (Tim-3 Treg KO) model, we found a significant decrease in morbidity during LCMV chronic infection. Tim-3 Treg KO mice mounted a higher virus-specific T cell response and had lower viral burden in blood, liver, and kidney at 30dpi. Lack of Tim-3 expression on Treg limited their ability to upregulate IL-10, TGFb, CD39, PD-1, CD25, CTLA-4 and CD44. Similarly, in PWH Tim-3+ Treg have increased expression of IL-10 compared to HIV(−). In addition, Tim-3+ Treg from PWH show significant upregulation of Ki67+, CD73+, Gzmb+ and TGFb+ compared to their Tim-3− Treg counterpart. Our findings demonstrate that modulation of a surface protein in Treg can lead to a reduction in viral burden and enhance LCMV-specific T cell response. We found that Tim-3+ Treg have an increased suppressive phenotype, compared with Tim-3− Treg in PWH, regardless of viral suppression. Elucidation of the mechanism of Tim-3 function in Treg may provide insights into the biology of chronic infections and for developing novel potential strategies to achieve HIV remission off ART.
Supported by grants from NIH (T32GM008208, R01AI138504, U01AI131285)
Upregulation of CD9 identifies cytokine-producing T follicular helper (Tfh) cells during viral infection
Authors: Antao Olivia Quinn , Sanchez Gina M , Mayer Daniel , Weinstein Jason S 
Published: January 2023

Abstract
T follicular helper (Tfh) cells, a subset of CD4+ T cells, critically regulate the adaptive immune response by promoting germinal center (GC) B cell maturation into memory B cells and antibody secreting plasma cells. Tfh cells promote the GC response through the production of canonical cytokines IL-21 and IFNg, or IL-4 and CD40L signaling. Tfh cells progressively differentiate to regulate the germinal center response, but other than previous studies using cytokine reporter mice, the stages of this differentiation remain unclear. We identified that CD9, a tetraspanin protein, is temporally upregulated on a subset of Tfh cells following acute LCMV infection. To assess the function of the CD9 expressing Tfh cells, we compared migration to GC honing chemokines CXCL12 and CXCL13 and cytokine production between CD9hi and CD9lo Tfh cells at 8 days post LCMV infection. We found that CD9hi Tfh cells exhibited enhanced migration to CXCL12 and CXCL13 compared to CD9lo cells. Ex vivo stimulation of Tfh cells revealed that the CD9hi subsets were the primary producers of IL-21 and IFNg. Transcriptional analysis demonstrated that that CD9hi and CD9lo Tfh cells are distinct subsets characterized by enhanced expression of cell cycling genes in the CD9hi fraction. Thus, not only does CD9 identify the cytokine producing population of Tfh cells but marks a functionally and transcriptionally distinct subset promoting GC responses during viral infections.
Ena/VASP protein-mediated actin polymerization contributes to naive CD8+ T cell activation and expansion by promoting T cell-APC interactions in vivo
Authors: Waldman Monique M , Rahkola Jeremy T , Willett Benjamin A S , Chung Jeffrey W , Sigler Ashton L , Friedman Rachel S , Kedl Ross M , Jacobelli Jordan 
Published: January 2023

Abstract
Naive T cell activation in secondary lymphoid organs such as lymph nodes (LNs) occurs upon recognition of cognate antigens presented by antigen presenting cells (APCs). T cell activation requires cytoskeleton rearrangement and sustained interactions with APCs. Ena/VASP proteins are a family of cytoskeletal effector proteins responsible for actin polymerization and are frequently found at the leading edge of motile cells. Ena/VASP proteins have been implicated in motility and adhesion in various cell types, but their role in primary T cell activation has not been explored. Our goal was to determine the contribution of Ena/VASP proteins to T cell activation and expansion in vivo. Our results showed that naïve T cells from Ena/VASP-deficient mice have a significant reduction in antigen-specific T cell accumulation following Listeria monocytogenes infection. The kinetics of antigen-specific T cell impairment were further confirmed in Ena/VASP-deficient T cells stimulated via dendritic cell immunization. To investigate the cause of this T cell expansion defect, we analyzed T cell-APC interactions in vivo by 2-photon microscopy and observed fewer Ena/VASP-deficient naïve T cells interacting with APCs in LNs during priming. We also found that Ena/VASP-deficient T cells formed conjugates with significantly less actin polymerization at the T cell-APC synapse, and that these conjugates were less stable than their WT counterparts. Thus, we conclude that Ena/VASP proteins contribute to T cell actin remodeling downstream of T-APC interactions required for the initiation of stable T cell conjugates during APC scanning and for efficient activation and expansion of T cells in vivo.
Supported by NIH (R01AI125553; T32AI007405)
Macrophage inflammatory response increases in adult female exposed to neonate stress
Authors: Bouchard Karine , Patoine Dany , Fournier Stephanie , Lerdu Ophélie , Marsolais David , Kinkead Richard , Bissonnette Elyse , Lauzon-Joset Jean-Francois 
Published: January 2023

Abstract
Impacts of stress on the immune system vary depending on the nature, intensity, and time during which stress is experienced (eg, acute stress is pro-inflammatory vs chronic stress is anti-inflammatory). However, there is limited knowledge on the long-term impact of early life stress on immune responses. Given that immune programming occurs early in life and that immunity and stress both involve sexual dimorphisms, our hypothesis is that neonatal maternal separation (NMS) induces sex-specific immune alterations.

Objective
Our objective is to evaluate the influence of early life stress on immune response in adult and its dimorphism related to biological sex.

Methods
We used a well-established rat model of early life stress, NMS, in which we observed sex-specific modulations of the myeloid compartment. Thus, we evaluated the impact of NMS on macrophage activation using LPS stimulation of bone-marrow derived macrophages (BMDM) in vitro. Expression of activation (MHCII, CD40, CD86 and CD80) and maturation markers (SIRPα, CD11b, CD200 and CD200R) were analyzed by flow cytometry. TNF levels were measured by ELISA.

Results
LPS stimulation of female NMS BMDM had higher expression of activation markers compared to controls. Inflammatory cytokine levels, TNF, increased after LPS stimulation and further increased in female NMS, whereas male NMS level was lower than control male. Futhermore, LPS stimulation lowered CD200 receptor (CD200R) to a greater extent in male NMS than in female NMS.

Conclusion
These results suggest that NMS accentuates the pro-inflammatory response in adult female (but not in male) and will provide a strong base for improving sex-specific interventions in the context of diseases involving stress and the immune system.
Supported by grants from CIHR, QRHN and CRIUCPQ
Costimulation of TLR8 responses by CXCL4 in Human Monocytes Mediated by TBK1-IRF5 Signaling and Epigenomic Remodeling
Authors: Yang Chao , Bachu Mahesh , Brauner Caroline , Yuan Ruoxi , Du Yong , Ah Kioon Marie Dominique , Chesi Giancarlo , Barrat Franck J , Ivashkiv Lionel B 
Published: January 2023

Abstract
CXCL4 regulates responses of immune cells to endosomal TLRs and has been implicated in the pathogenesis of inflammatory and fibrotic diseases. However, mechanisms by which CXCL4 modulates TLR responses, and its functions in monocytes/macrophages, are still unclear. Here we report that CXCL4 changes the profile of the TLR8 response in human monocytes by selectively and dramatically amplifying inflammatory gene transcription and IL-1b production while partially attenuating the IFN response. Mechanistically, costimulation by CXCL4 and TLR8 synergistically activated TBK1/IKKe and repurposed these kinases towards an inflammatory response via coupling with IRF5, and by activating the NLRP3 inflammasome without the need for a second signal. CXCL4 strongly induced chromatin remodeling in a cooperative and synergistic manner with TLR8 signaling, inducing de novo enhancers associated with inflammatory genes. These findings identify signaling and epigenomic mechanisms that underly synergistic activation of inflammatory genes by CXCL4 and TLR8, provide a new paradigm for modulation of TLR responses that is relevant for cytokine storm, and suggest targeting the TBK1/IKKe-IRF5 axis may be beneficial in inflammatory diseases.
MicroRNAs modulate Chlamydia trachomatis infection- and vaccine-induced immunity in macrophages
Authors: Eko Francis , Bell Cortnee , Jones Leandra , Medhavi Fnu , Tanner Tayhlor , Omosun Yusuf , Igietseme Joseph U 
Published: January 2023

Abstract
Recent studies indicate that microRNAs (miRNAs), including immune cell type-specific miRNAs modulate inflammation and immune response to Chlamydia trachomatis (CT) genital infection. However, the role of these miRNAs in modulation of immune cell function following CT infection or vaccine stimulation has not been investigated. We hypothesized that pretreatment of CT-infected and vaccine-stimulated macrophages with miRNA mimics or inhibitors will modulate secretion of inflammatory cytokines and expression of IFN-γ pathway-related genes. Thus, THP-1-differentiated macrophages (TDM) transfected with miRNA mimics or inhibitors were infected with CT or stimulated with a Vibrio cholerae ghost (rVCG)-based vaccine (rVCG-MECA) and the level of inflammatory cytokines secreted in culture supernatants was assessed by cytokine ELISA. Also, TDM expression of IFN-γ pathway-related genes was assessed by RT-qPCR. The results show that CT infection of TDM resulted in the downregulation of miR-15a, miR-29a, miR-146a and miR-222 while stimulation with rVCG-MECA resulted in their upregulation, as we previously reported. The level of TNF-α, IL-8, IL-1β and IFN-γ secreted by miRNA mimic- or inhibitor-treated TDM following infection or vaccine stimulation was dependent on the miRNA type. Furthermore, CT infection of untreated macrophages increased mRNA expression of INFGR1, JAK2, STAT1 and SOCS1. However, pretreatment of CT-infected cells with miR-146a mimic or inhibitor showed significantly decreased expression of these genes. The study demonstrated that miRNAs differentially modulate macrophage secretion of inflammatory cytokines and expression of IFN-γ pathway-related genes following CT infection or vaccine stimulation.
Supported by None.
Anti-inflammatory Response Induced by Exopolysaccharide of the Probiotic Bacillus subtilis
Authors: Zamora-Pineda Jesus Bernabe , Knight Katherine L 
Published: January 2023

Abstract
Probiotics can lessen the severity of intestinal inflammatory diseases, although the mechanisms by which this occur are poorly understood. We showed that exopolysaccharide (EPS) from the probiotic Bacillus subtilis induces anti-inflammatory macrophages and protects mice from enteric infection and sepsis. Here, we examined the molecular mechanisms by which EPS induces an anti-inflammatory response. In co-cultures of OVA-loaded bone marrow-derived dendritic cells (BMDC) and OT-II T cells, EPS inhibits T cell activation in a TLR4-dependent manner. We hypothesize that EPS engages TLR4 and activates the noncanonical NF-kB signaling pathway, which up-regulates the expression of indoleamine 2,3-dioxygenase (IDO). IDO degrades the essential amino acid tryptophan into kynurenine, which leads to suppression of T-cell activation and induction of tolerance. Western blot analysis of BMDCs treated with EPS showed nuclear translocation of the transcription factor RelB, which is central to the noncanonical pathway and upregulation of IDO. Inhibition of IDO using the inhibitor 1-methyl tryptophan, and ido1−/− BMDCs reverse the effect of EPS. We conclude that EPS inhibition of T cell activation and proliferation is mediated by IDO. We have identified a novel mechanism for immune protection by a probiotic molecule.