bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESX5 associated PE proteins of Mycobacterium tuberculosis drives Th1 type polarization: an immunomodulatory paradigm
Authors: Ehtram Aquib , Shariq Muhammed , Ali Sabeeha , Ehtesham Nasreen Z. , Hasnain Seyed E. 
Published: January 2023

Abstract
Mycobacterium tuberculosis (M.tb) harbors various effector molecules that affect human immune system. There exists a varied difference between the slow growing pathogenic mycobacteria compared to the fast growing non-pathogenic strains. One marked difference is the presence of ESX5, a type VII secretion system that is found to be most recently evolved and has been acquired by the pathogenic M.tb. ESX5 is involved in the secretion of an enigmatic PE/PPE family of proteins that are exclusive to the genus mycobacteriacea. PE/PPE are the effector virulent molecules that play vivid role in modulating host immune system. ESX5 locus has 2 pe genes and 3 ppe genes. Of the translated products, two PE proteins are paralogs, but contrastingly found to have different PPE binding partners as these proteins function as heterodimers, homodimers and individual proteins. THP1 macrophages (differentiated human monocytes) when treated with different micro-concentrations of PE 1X and PE 1Y induce differential Th1 type cytokine responses. PE 1X and PE 1Y induced stronger TNF-α response at 24hrs of protein exposure that increased markedly at 48hrs. IL-12 p70 was found to decrease from 24hrs to 48hrs during PE 1X treatment whereas PE 1Y exposure led to the secretion of IL-12 p70 which was constantly maintained from 24hrs to 48hrs of exposure time. PE 1X specifically mediated TLR2 dependent activation of macrophages that was responsible for the secretion of pro-inflammatory cytokines. On the contrary PE 1Y activated macrophages through TLR4 dependent cascade. These results therefore, conclude that PE 1X and PE 1Y contribute profoundly towards Th1 polarization of the immune response.
Immune responses to Dengue infected microvascular endothelial cells
Authors: Sekaran Shamala Devi , Soe Hui Jen , Raju Chandramathi Samudi , Manikam Rishya , Vellasamy Shalini 
Published: January 2023

Abstract
Severe dengue is associated with manifestations such as bleeding, fluid accumulation and organ impairment. This study aimed to investigate the role of dengue non-structural 1 (NS1) protein and host factors contributing to severe dengue. Electrical cell-substrate impedance sensing system was used to investigate the changes in barrier function of microvascular endothelial cells treated NS1 protein and serum samples from dengue patients. Cytokines and metabolites profiles were also assessed. Our study revealed that dengue NS1 protein was able to induce the loss of barrier function of the microvascular endothelium in a dose dependent manner. However, the level of NS1 did not correlate with the extent of vascular leakage observed in the microvascular endothelium treated with serum samples from patients with dengue virus infection. This implies presence of other host factors that might overshadow the direct effect of NS1 in inducing vascular leakage during dengue virus infection. Most of the cytokines that were highly expressed in dengue patients including CCL2, CCL5, CCL20 and CXCL1 are involved in leukocyte infiltration where the rearrangement of junctional complex proteins such as ICAM-1, which was detected significantly higher in patients with SD, may lead to the disruption of inter-endothelial junctions. Altered lipid metabolism was detected in in patients with DWWS and SD. This might be associated with phospholipid metabolism, which may affect the membrane permeability of cells including the microvascular endothelium. The identification of these altered metabolites could facilitate dengue diagnosis or be used as a potential target for new therapeutic options.
Modeling a human STAT4 mutation that predisposes to disseminated Coccidioidomycosis in mice
Authors: Powell Daniel A , Shubitz Lisa F , Butkiewicz Christine D , Moale Hilary , Trinh Hien T , Doetschman Thomas , Hsu Amy P , Holland Steven M , Galgiani John N , Frelinger Jeffrey A 
Published: January 2023

Abstract
Coccidioidomycosis is a common fungal respiratory disease caused by the fungus Coccidioides spp. fungi in Arizona and the central valley of California. Disseminated Coccidioidomycosis (DCM) occurs in 8% of identified cases, causing significant morbidity and mortality. DCM occurred in 3 generations of a family in Tucson, Arizona who all shared a heterozygous missense mutation (p.E626G) in STAT4. Transfection of STAT4 E626G in WT human cells showed dampened responses to STAT4-dependent cytokine gene induction, suggesting the mutation is a dominant negative.
To understand the function of E626G mutation, we generated the homologous mutation in Stat4 in B6 mice. Mice carrying E626G were grossly normal with normal numbers of innate and adaptive immune cells in primary and secondary lymphoid organs. To examine the effect of E626G on susceptibility to Coccidioides infection, we infected mice with C. posadasii strain 1038 intranasally. After infection E626G heterozygous mice all died by 50 days post infection (dpi), median time to death 45.5 days; range 30–50 dpi. 87% of WT B6 controls were alive when the experiment ended at a predetermined 70 dpi, resulting in a median time to death of &gt;70 days. Mediastinal lymph nodes in E626G heterozygous mice had reduced numbers of B cells and activated (CD62Llow) T cells compared to B6 controls on 14 dpi. Cells from infected lungs from E626G heterozygotes produced less IFN-gamma after infection on 28, 35 and 42 dpi. Interferon stimulated cytokines (IP-10, MIG, MIP-2) were also significantly reduced compared to WT controls. Ongoing work includes examining the cells requiring STAT4 signaling and IFN-gamma production as well as the mechanism of reduced accumulation of immune cells in the draining lymph nodes.
Clostridia protect from food allergy by promoting intestinal barrier integrity and modulating retinoic acid metabolism
Authors: Kemter Andrea Maria , Wang Shan , Nagler Cathryn 
Published: January 2023

Abstract
We previously reported that intestinal bacteria of the Clostridia class modulate epithelial barrier function through induction of IL-22 and hypothesized that this was crucial for their allergy protective effect. We now confirm that hypothesis and further describe the mechanisms underlying this protection. Clostridia colonization of weanling germ free mice induced colonic IL-22 production and expression of the antimicrobial peptides Reg3b and Reg3g within three days. At the same time, the numbers of CD11b+, CD103+ and CD11b+CD103+ dendritic cells (DC) in the colonic lamina propria were reduced, while the number of macrophages remained unaltered. Seven days post colonization, the numbers of those same DC subsets were increased in the colon draining mesenteric lymph node (cMLN) and we detected an increased ability to produce retinoic acid (RA) in CD11c+ cells in the cMLN. We also observed increased expression of Reg3b, Reg3g and the retinol dehydrogenase Rdh7 in the ileum and the RA-responsive gene Isx in colon epithelial cells. At 14 days, Clostridia colonization increased percentages of RORγt+ Foxp3+ regulatory T cells (Tregs), which are known to efficiently suppress type 2 immune responses. Finally, preliminary data showed that the TLR5 ligand flagellin replicates Clostridia-induced production of IL-22 and intestinal barrier protection but not modulation of RA metabolism. With the rapid induction of IL-22, which supports intestinal barrier integrity, and the slower modulation of retinoic acid metabolism and Treg induction we describe two mechanisms by which Clostridia promote tolerance to food antigens. Detailed knowledge of these mechanisms will enable us to develop new strategies to combat the dramatic rise of food allergies.
Microbial enzyme stereoselectively converts EPA into 17(S),18(R)-epoxyeicosatetraenoic acid useful for the amelioration of contact hypersensitivity
Authors: Saika Azusa , Nagatake Takahiro , Kishino Shigenobu , Park Si-Bum , Honda Tetsuya , Matsumoto Naomi , Shimojou Michiko , Morimoto Sakiko , Tiwari Prabha , Node Eri , Hirata So-ichiro , Hosomi Koji , Kabashima Kenji , Ogawa Jun , Kunisawa Jun 
Published: January 2023

Abstract
Dietary intake of ω3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid are beneficial for health control because ω3 fatty acids are metabolized to pro-resolution and anti-inflammatory lipid metabolites. We previously identified 17,18-epoxyeicosatetraenoic acid (17,18-EpETE) as a new lipid metabolite endogenously generated from EPA that exhibits potent anti-allergic and anti-inflammatory properties. However, the chemically synthesized 17,18-EpETE is enantiomeric mixture concerning to its epoxy group, i.e., 17(S),18(R)-EpETE and 17(R),18(S)-EpETE, and the stereostructural differences in anti-inflammatory effect of 17,18-EpETE has not been clarified. Because it is necessary to identify which isomer shows physiological function to develop it as a medicine, we evaluated stereospecific effects of 17(S),18(R)-EpETE and 17(R),18(S)-EpETE in amelioration of skin contact hypersensitivity. As a result, we found that anti-inflammatory activity was detected in 17(S),18(R)-EpETE, but not 17(R),18(S)-EpETE. In addition, we found that cytochrome P450 BM-3 derived from Bacillus megaterium stereoselectively converts EPA into 17(S),18(R)-EpETE, which effectively inhibited the development of contact hypersensitivity by inhibiting neutrophil migration in a G protein-coupled receptor 40-dependent manner. These results demonstrated that immune cells (e.g., neutrophils) distinguish biological active lipid metabolites stereoselectively for the control of their activity, which is a new strategy for the development of efficient immunotherapy.
Regulation of thymic T-cell development by intestinal microbiota
Authors: Majumdar Shubhabrata , Ruiz Daniel Zegarra , Wu Wan-Jung , Orozco Stephanie , Bettini Maria , Diehl Gretchen , Bettini Matthew L. 
Published: January 2023

Abstract
Host commensal microbiota plays an important role in the development and functioning of a healthy immune system. Early life interference with commensal colonization is associated with immune disorders like inflammatory bowel disease (IBD), asthma, allergic rhinitis and atopic dermatitis. One important aspect of microbiota mediated immune regulation is its impact on T-cell differentiation and function. Although most studies show that microbial regulation of T-cells is limited to the periphery, some studies have suggested that the microbiota might impact antigen specific T-cell development in the thymus. However, there has been insufficient data. Interestingly, we are able to detect bacterial signatures by 16s sequencing within mouse and human thymus. Additionally, we observed development of antigen specific thymocytes in SFB colonized 7B8 TCR transgenic mice and in wildtype mice through SFB tetramer staining. We therefore, hypothesize that antigen-presenting cells (APCs) from the gut sample local microbial antigens and migrate to the thymus to present them to the developing thymocytes and influence selection. To test this hypothesis, we tracked the migration of intestinal APCs to the thymus using mice that express the photoconvertible Kikume protein. We performed targeted photo-conversion of the cecum through live surgery and discovered photoconverted APCs in the thymus 48 hours later. These observations open up the possibility that intestinal APCs migrate to the thymus early in life to shape the microbiota specific TCR repertoire.
Innate CD8αα cells orchestrate intraepithelial lymphocytes balance and protect against colitis
Authors: Nazmi Ali , Hoek Kristen L. , Tansie Stephen , Piazuelo M. Blanca , Olivares-Villagómez Danyvid 
Published: January 2023

Abstract
Innate CD8αα+ cells (iCD8α) are TCRneg intraepithelial lymphocytes (IEL) that possess immune functions such as phagocytosis, bacteria killing, and antigen processing and presentation. Recently our group and others reported that iCD8α cells promote IEL survival via osteopontin. Herein, we investigate whether iCD8α cells sustain intestinal homeostasis through maintaining IEL balance.
We compared the number of IEL in the colon of WT and iCD8α-deficient mice (E8i−/−). E8i is an enhancer required for CD8α homodimer expression in IEL. Despite the dramatic reduction of CD8αα expression on TCRαβ+ and TCRgd+ IEL in E8i−/− mice, the total cell numbers were comparable to WT mice. E8i−/− mice had higher number of TCRβ+CD4+, and lower number of TCRβ+CD4+CD8α+ and TCRβ+CD8αα+ IEL. There were no differences in TCRβ+CD8αβ+ and TCRneg IEL.
Then, we tested the role of iCD8α cells during intestinal inflammation in different colitis models. iCD8α-deficient mice had higher susceptibility to Citrobacter rodentium infection as indicated by increased weight loss, disease index, and bacterial load in the colon compared to WT mice. Similar results were obtained using DSS-induced colitis: E8i−/− mice presented increased shortening of colon and pathological scores. Finally, we performed adoptive transfer of naïve CD4 T cells into Rag-2−/− and E8i−/−Rag-2−/− mice. iCD8α-deficient mice rapidly developed chronic colitis, manifested by sever weight loss and bloody diarrhea. These mice also reconstituted with higher number of donor-derived CD4 T cells that mostly developed into pathogenic TCRβ+CD4+ IEL.
Our results indicate that iCD8α cells have a critical role in the maintenance of IEL homeostasis and healthy intestines.
Resident memory CD8 T cells patrol the lung and mediate early protective immunity
Authors: Anthony Scott M , Langlois Ryan A , Varga Steven M , Harty John T 
Published: January 2023

Abstract
In contrast to the long-lived nature of resident-memory CD8 T cells (Trms) residing in the skin or intestine, Trms located in the lung parenchyma wane and their loss coincides with the decline of protective immunity against subsequent heterosubtypic Influenza infections. We utilized intravital 2-photon microscopy of live mice to dissect the relative contribution and examine the real-time spatiotemporal dynamics of secondary CD8 T cell responses containing or lacking lung Trms. Early post-Influenza infection, the lung contained a mixture of phenotypically defined circulating and CD69+/CD103+ resident-memory transgenic P14 cells which exhibited heterogeneous motility patterns, comprised of both highly motile cells and those exhibiting a slow to moderate scanning pattern. The incorporation of IV exclusion during intravital imaging predominantly labeled highly dynamic cells, and largely spared slower CD103+ Trms in the lung parenchyma and surrounding airways. Conversely, the selective loss of this slow to moderate population was observed with either CD103 antibody-mediated depletion of early memory or at 6 months post infection, suggesting that CD103+ CD8 Trms exhibit slow to moderate motility dynamics in the lung at homeostasis. Importantly, upon secondary infection, hosts containing Trms exhibited a higher proportion of CD8 T cells with altered dynamics, more pronounced clustering around infected cells in the lung in an antigen-specific manner and provided superior early heterosubtypic protection compared to hosts containing only circulating memory. Overall, these data indicate that lung Trms exhibit slow to moderate motility patterns, rapidly respond to and mediate early immunity to subsequent infections in the lung.
Ornithine-A urea cycle metabolite enhances autophagy and controls Mycobacterium tuberculosis infection
Authors: Thandi Ramya Sivangala , Radhakrishnan Rajesh kumar , Tripathi Deepak , Paidipally Padmaja , Vankayalapati Ramakrishna 
Published: January 2023

Abstract
Alveolar macrophages (AMs) are the first cells encountered by TB pathogen and serve as the primary defense against Mycobacterium tuberculosis (Mtb) in the lungs. Studies have shown that liver macrophages (Kupffer cells; KCs) can control Mtb growth but, it is not clear how KCs completely eliminate mycobacterial infections. Thus, identification of these mechanisms will facilitate the development of immunomodulatory strategies to boost AM-mediated immunity to Mtb. In the current study, we compared Mtb growth in murine AMs, peritoneal (PMs), liver macrophages (Kupffer cells; KCs) and bone marrow-derived monocytes (BDMs). KCs restricted Mtb growth more efficiently than all other macrophages and monocytes despite equivalent infections. Differences in Mtb growth restriction were not due to differences in cytokine production, expression of Toll-like receptors 2 and 4, M1/M2 paradigm or apoptosis. We provide evidence that the enhanced autophagy efficiently restricts Mtb growth in KCs using flow cytometry, western blot, RT-PCR and confocal microscopy. A metabolomic comparison of Mtb-infected macrophages by liquid chromatography mass spectrometry indicated that ornithine (VIP=1.8) and imidazole (VIP=1.6) were two top-scoring metabolites found in Mtb-infected KCs and that acetylcholine was top-scoring in Mtb-infected AMs. Ornithine and imidazole inhibited Mtb growth in AMs by enhancing AMPK mediated autophagy whereas imidazole directly killed Mtb by reducing cytochrome P450 activity. Intranasal delivery of ornithine or imidazole or together restricted Mtb growth in Mtb-infected mouse lungs. Our study demonstrates that the metabolic differences in Mtb-infected AMs and KCs leads to differences in the restriction of Mtb growth.
Regulation of Respiratory CD8+ T cell Immunity by Suppressive Monocyte Derived Dendritic Cells (moDCs)
Authors: Reagin Katie L , Klonowski Kimberly D 
Published: January 2023

Abstract
Active immune suppression can mediate the balance between protective cellular immunity and harmful immunopathology. This suppression can occur locally, at an infection site, or in regional draining lymph nodes (dLN). Immune regulation is of particular importance in sites such as the lung where aberrant immunopathology can result in loss of tissue function. We have recently identified a novel population of CD11b+CD103+CCR2+monocyte-derived dendritic cells (moDCs) which directly suppress CD8+ T cell proliferation in vitro. Respiratory infection with RNA viruses recruits these moDCs either exclusively to the dLN (after vesicular stomatitis virus infection) or both the dLN and site of viral replication (after influenza infection). Exclusive depletion of moDCs from the dLN using CCR2-DTR bone marrow chimeras results in enhanced respiratory CD8+ lung tissue resident memory cell formation. By contrast, depletion of moDCs from both the dLN and respiratory tract following influenza infection results in enhanced respiratory CD8+ T cell responses coupled with fatal immunopathology. Together, these data suggest that suppressive moDCs govern key aspects of respiratory immunity by regulating the function and development of long-lived CD8+ T cells, thereby balancing immunity and adverse pathology in the context of viral infection. Ongoing experiments seek to uncouple moDC interactions with CD8+ T cells in specific sites in order to better understand, and potentially beneficially modulate, CD8+ T cell immunity within the lung.
Empty-loadable MHC class I tetramers for efficient detection of antigen-specific T cells
Authors: Tamhane Tripti , Saini Sunil Kumar , Anjanappa Raghavendra , Saikia Ankur , Ramskov Sofie , Donia Marco , Swane Inge Marie , Jakobsen Søren Nyboe , Zacharia Martin , Meijers Rob , Springer Sebastian , Hadrup Sine 
Published: January 2023

Abstract
The peptide-dependent stability of MHC class I molecules poses a substantial challenge for their use for peptide-MHC multimer-based approaches to comprehensively analyze T cell immunity. We demonstrate here the generation, analysis, and use of empty-loadable (peptide-free) MHC class I tetramers made from disulfide-stabilized MHC molecules.
A disulfide bond links the α1 and α2 helices of MHC class I molecule at the extreme end of the F pocket. It allows in vitro folding of recombinant A2 with a dipeptide and subsequent removal of the dipeptide to yield stable peptide-receptive MHC monomers. Empty-loadable tetramers prepared using disulfide-stabilized MHC monomers can be loaded with peptides within minutes. These tetramers efficiently detects antigen-specific T cells. Furthermore, peptide-MHC tetramers prepared using disulfide-stabilized MHC molecules provide a better staining index for antigen-specific T cell detection compared to multimers prepared with wild-type MHC class I molecules. We demonstrate the value of empty-loadable tetramers that are converted to antigen-specific tetramers by a single-step peptide addition, for the identification of T cells specific to several neo- and cancer-associated antigens in melanoma. Disulfide stabilization has been achieved with several MHC class I allotypes-HLA-A* 02:01, HLA-A*01:01, HLA-A*03:01, HLA-A*11:01, HLA-A*24:02, HLA-B*07:02, and H-2Kb.
Use of TCR-mimic bispecific antibodies against pMHC-II for monitoring antigen processing and redirecting cytolytic effector cells
Authors: Sengupta Srona , Douglass Jacqueline , Wu Fengting , Moskovljevic Milica , Reed Madison , Yu Jeanna , Tabdili Yasmine , Hsiue Emily Han-Chung , Veenhuis Rebecca , Vogelstein Bert , Siliciano Janet , Siliciano Robert , Sadegh-Nasseri Scheherazade 
Published: January 2023

Abstract
HIV-1 infects CD4+ T cells and macrophages and is currently incurable due to a latent reservoir. Targeting infected cells using TCR-mimic antibodies to peptide-MHC (pMHC) would provide a specific, high-affinity platform for immune system activation and monitoring antigen processing. However, antibodies to pMHC are notoriously difficult to isolate. Using a phage display platform, we panned for phage expressing variable fragments against immunodominant HIV pMHC complexes. These Fab fragments were cloned into a bispecific antibody (bsAb) backbone, such that one Fab fragment is specific for an HIV pMHC and the other fragment binds to CD3. These antibodies utilize the sensitivity of T cell signaling as readouts for antigen processing and potentially as therapeutic formats. Using this approach, we have shown that bsAbs specific for the most conserved MHC-II HIV capsid epitope (Gag293) can recognize the processed epitope on human monocyte-derived dendritic cells (moDCs) fed with the whole Gag protein antigen. Recognition is exquisitely epitope-specific. Additionally, human monocyte-derived macrophages infected with HIV were able to present Gag293 using the endogenous MHC-II pathway, as read out by a Gag-specific bsAb. To our knowledge, this is the first description of endogenous class II presentation of HIV in a major cell type that supports viral replication. By developing bsAbs to detect HIV peptide presentation, we can begin to address the kinetics, pathways, and cell types contributing to the priming events in early HIV infection, which will inform improved vaccine therapies. Additionally, given the potential for therapeutic application, these bsAbs may be used to redirect cytolytic effector cells towards infected targets.