bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foreign epitope-specific regulatory T cells respond robustly to vaccination and limit Th1 differentiation by conventional T cells specific for the same epitope
Authors: Krueger Peter D , Jenkins Marc K 
Published: January 2023

Abstract
CD4+ naïve T cell populations specific for MHCII-bound foreign peptides contain FOXP3− conventional (Tconv) cells and less abundant FOXP3+ regulatory (Treg) cells. Little is known about how naïve Treg cells respond to foreign peptides and for what purpose given that their activation might impede immunity. We addressed this issue by tracking naïve T cells after vaccination with a foreign peptide in an oil-based adjuvant. The Tconv and Treg naïve cells specific for the peptide proliferated extensively during the first week after vaccination. The Tconv population generated only Tconv progeny, mainly of the T helper 1 (Th1) and follicular helper (Tfh) varieties. Most of the naïve Treg cells formed Th1- or T helper 17 (Th17)-like Treg progeny while a minority lost FOXP3 and adopted a Tfh phenotype. The Treg progeny limited the formation of conventional Th1 cells in peptide-specific manner. Thus, foreign peptide-specific naïve Treg cells undergo a robust primary response that generates progeny resembling Th1 and Th17 cells that limit differentiation of their conventional Th1 counterparts.
IFN-γ signaling is essential for the clearance of C. neoformans in the brain and survival of the infected mice
Authors: Chen Yanli , Strickland Ashley , Shi Meiqing 
Published: January 2023

Abstract
Cryptococcus neoformans is an encapsulated pathogenic fungus, which primarily infects immunocompromised individuals including HIV-infected patients, organ transplant recipients, and patients treated with immunosuppressive drugs. Each year, about 180,000 people die from cryptococcosis. Although it is believed that C. neoformans enters the body through the airway and initially causes infections in the lung, cryptococcosis commonly presents as meningoencephalitis. Previous studies mainly focused on immune responses to C. neoformans in the lung, and little is known about mechanisms involved in the clearance of the organism in the brain. IFN-γ signaling has been previously shown to play a critical role in control of the fungal infections in the lung. In the current study, we characterize the role of IFN-γ signaling in the clearance of C. neoformans in the brain using a mouse model of brain infections. The results show that IFN-γR−/− mice died significantly earlier compared to wild-type mice following intravenous infection with C. neoformans. Infected IFN-γR−/− mice displayed significantly higher fungal burden in the brain with enlarged lesion size compared to infected wild-type mice. The impaired clearance of C. neoformans in the brain of IFN-γR−/− mice was associated with reduced production of proinflammatory cytokines in the brain, altered recruitments of leukocytes to the brain, and M2-type polarization of microglia. We conclude that IFN-γ signaling is essential for the clearance of C. neoformans in the brain and survival of the infected mice.
Glucuronoxylomannan in the Cryptococcus species capsule as a target for CAR+ T-cell therapy
Authors: Kumaresan Pappanaicken , daSilva Thiago , Laskowski Tamara 
Published: January 2023

Abstract
The genus Cryptococcus comprises two major fungal species that cause clinical infections in humans: C. gattii and C. neoformans. Each year, about 1 million cases of Cryptococcus infection are reported worldwide, and the infection’s mortality rate ranges from 20% to 70%. To combat the cryptococcosis, we proposed the redirection of CD8+ T cells to target glucuronoxylomannan (GXM), a sugar present in the Cryptococcus species capsule, via expression of a GXM-specific chimeric antigen receptor (GXMR-CAR) for treatment of cryptococcosis. GXMR-CAR has an anti-GXM single-chain variable fragment followed by an IgG4 stalk, a CD28 transmembrane domain, and CD3-zeta and CD28 signaling domains. After lentiviral transduction of human T cells with the GXMR-CAR construct, flow cytometry demonstrated that 82.4% of the cells expressed GXMR-CAR on their surface. To determine whether the GXMR-CAR+ T cells exhibited GXM-specific recognition, these cells were incubated with GXM for 24 h and examined using bright-field microscopy. Large clusters of proliferating GXMR-CAR+ T cells were observed, while no clusters were present in the control cells. The ability of GXMR-CAR T cells to bind to the yeast form of C. neoformans was detected by flow cytometry and fluorescent microscopy, but no binding was detected in mock-transduced control T cell (NoDNA T cells). Furthermore, when GXMR-CAR+ T cells were administered to immunocompromised NSG mice infected with C. neoformans their C. neoformans burden was significantly lower than mock-transduced control T cell treated mice as shown via immunofluorescence using an anti-GXM antibody and Gomori methenamine-silver (GMS) staining of Titan cells in lung tissue.
Correlation of DNA Methylation Status and Immune Function in the Cytotoxic Immune Cells of Tuberculosis Patients
Authors: Nishiguchi Tomoki , Mtetwa Godwin , Kay Alexander , Maphalala Gugu , Mandalakas Anna , Coarfa Cristian , DiNardo Andrew 
Published: January 2023

Abstract

BACKGROUND
Less than 10% of individuals infected with Mtb develop disease. Similarly, in the pre-antibiotic era, ~20% of Tuberculosis (TB) patients overcame the disease. This implies host immunity can control Mtb infection. We evaluated the role of cytotoxic immune cells (CD8, CD56 and CD3+CD56+) among individuals with chronic infections that increase risk of TB progression.

METHODS
DNA Methyl EPIC was evaluated in patients with helminths, HIV and TB (n = 32) and flow-based immune phenotyping was implemented on 108 individuals. Gene expression of 717 TB patients and 525 healthy controls was downloaded from publicly available databases.

RESULTS
All evaluated cytotoxic cells displayed DNA methylation perturbations in the IL-2-STAT5, PI3K and IFNγ signaling pathways. TB patients experienced DNA hyper-methylation of perforin in CD56 NK cells and in granzyme A and granzyme B of CD8+ cytotoxic lymphocytes (CTLs). By flow cytometry TB patients up-regulated mycobacterial-specific perforin in CTLs while CD3−CD56+ NK cells expressed decreased perforin. Early evidence suggests that the increased perforin expression from CTLs was heterogenous and only occurs in ~46% of TB patients. Further evidence for heterogenous TB sub-groups was demonstrated by gene expression as 333 TB patients had increased perforin gene expression, while 313 had decreased gene expression (log2 fold change with FDR &lt; 1%).

CONCLUSION
To evaluate the DNA methylation-immune phenotype associations from this clinical cohort, mechanistic studies manipulating DNA methylation status are undergoing. Identifying how epigenetic modifications alter cytotoxic cells capacity to kill intracellular mycobacteria is critical to future host directed therapeutic options.
Role of meningeal lymphatic vessels in the T cell response against Toxoplasma gondii
Authors: Kovacs Michael , Smirnov Igor , Batista Samantha J. , Cowan Maureen N. , Still Katherine M. , Bolte Ashley C. , Harris Tajie H. 
Published: January 2023

Abstract
Toxoplasma gondii is an intracellular protozoan parasite that causes persistent infection in the central nervous system (CNS). Studies have demonstrated that continuous T cell recruitment to the brain is necessary for parasite control. However, the mechanisms by which T cell responses against T. gondii are maintained remain poorly understood. Recently, it was discovered that the meninges harbor a previously unappreciated lymphatic network that drains CNS protein and immune cells. We hypothesized that the meningeal lymphatic network is necessary for maintaining host-protective T cell responses against T. gondii. To test this hypothesis, we performed surgical ligation of the lymphatic vessels that carry cerebrospinal fluid via meningeal lymphatic vessels to the cervical lymph nodes. Following blockade of meningeal lymphatic outflow, we observed a decrease in the number and frequency of antigen-specific T cells in the deep cervical lymph nodes, supporting a role for meningeal lymphatic drainage in maintaining T cell responses against the parasite. We have also observed extensive lymphangiogenesis in the meninges during infection. Lymphangiogenesis has not previously been reported in response to CNS infection but could influence antigen or immune cell outflow from the CNS. Together, our results demonstrate that the meningeal lymphatic network dynamically responds to CNS infection with T. gondii and contributes to T cell responses against the parasite.
CD4 T cells are important in protection against M. tuberculosis reinfection in cynomolgus macaques
Authors: Ganchua Sharie Keanne C , Maiello Pauline , Hopkins Forrest , Fortune Sarah , Flynn JoAnne L 
Published: January 2023

Abstract
Early human studies show individuals with latent M. tuberculosis (Mtb) infection are less likely to develop active tuberculosis (TB) compared to naïve individuals with similar levels of exposure. Using Mtb-barcoded libraries (Lib A as first and Lib B as second infection), we published that an existing Mtb infection in cynomolgus macaques protects against the establishment and progression of a second Mtb challenge. CD4 T cells are important in control of TB, and depletion results in worse acute infection and latent TB reactivation in macaques. We hypothesized that CD4 T cells play a major role in protection against a secondary Mtb challenge. To test this hypothesis, CD4 T cells were depleted in infected and treated macaques before a second Mtb challenge. As controls, one group received IgG and a naive group received only Lib B. The number of Lib B granulomas in the IgG group was significantly fewer than in the naïve group, while the αCD4 group was in between the two. The IgG group had the lowest lung bacterial burden followed by the αCD4 group (16-fold higher than IgG) and lastly the naïve group (57.5-fold higher than IgG). Both reinfected groups (αCD4 and IgG) had a higher frequency of CD8 T cells producing IFNγ and/or TNF in Lib B granulomas compared to naïve macaques but there was no significant difference when compared to each other. Because each Mtb bacterium has a unique barcode, we can track the spread of Mtb to different organs. Both naïve and αCD4 groups had a greater number of unique Lib B barcodes in the thoracic lymph nodes compared to the IgG group. These data suggest that CD4 T cells help limit the establishment, progression and dissemination of the second infection. However, they are not the only factor responsible for protection against reinfection.
Effect of muscarine and atropine in the synthesis and secretion of IgA by T-dependent and T-independent mechanisms in small intestine of mice
Authors: Albor Aldo Arturo Resendiz , Rebollar-Ruíz Xóchitl Abril , Arciniega-Martínez Ivonne Maciel , Santamaría-Chávez Mónica Miguel , Campos-Rodríguez Rafael 
Published: January 2023

Abstract
IgA secretion is carried out through two pathways: T dependent in which the T cells cooperate in the production of this immunoglobulin and the T independent in which the isotype switch is made by mechanisms independent of CD4 T cells, each one of the pathways is identified by the expression of specific cytokines which are required to be able to switch the isotype. The enteric nervous system through acetylcholine and muscarinic and nicotinic receptors regulates the immune system however the mechanisms by which it does have not been completely elucidated, In this work we evaluated the effect it has muscarine and atropine in the secretion of total IgA and secretory IgA in the small intestine, the production of cytokines was measure in Th2 cells (IL-4, IL-5, IL-10, IL-12 and TGF-β) and the expression of independent T cytokines (APRIL, BAFF and BAFF receptor) in lamina propia (LP) and Peyer’s patches (PP). The results obtained we indicate that muscarine produces an increase in total IgA while atropine lowers it, the cytokines that increased with the agonist treatment were IL-5, IL-12 and TGF-β in PP while cytokines that decreased with the muscarinic antagonist were IL-4 and TGF-β in the LP. Besides the muscarine increased the expression of APRIL and BAFF in the inducer site and the effector site, the BAFF receptor in microvilli increase with muscarine in PP. In this study the muscarinic and nicotinic receptors regulates the secretion of total IgA in the small intestine in BALB/c mice.
This work was supported by SIP and COFFA IPN.
Tbet-expressing Tregs protect against lethal immunopathology during T. gondii infection
Authors: Wohlfert Elizabeth A , Warunek Jordan , Jin Richard M , Marzullo Brandon 
Published: January 2023

Abstract
Toxoplasma gondii infection has proven to be an ideal model to understand the delicate balance between protective immunity and immune mediated pathology. Tregs are necessary for maintaining immune homeostasis, particularly in the gut where immune tolerance to food and the microbiota is tightly regulated. Oral infection with T. gondii leads to a robust Th1 immune response initiating in the GI tract and has also been implicated in dysbiosis associated with inflammatory bowel disease. During T. gondii infection, Tregs highly express the Th1 lineage specifying transcription factor, Tbet, throughout infection. To determine the role of Tbet in Tregs, we infected Tbetf/f-Foxp3YFPCre and control Foxp3YFPCre mice with the type II strain ME49 T. gondii, Surprisingly, greater than 75% Tbetf/f-Foxp3YFPCre mice succumb to infection at peak acute infection while nearly 100% of the control Foxp3YFPCre mice survive. Analysis of parasite burden showed Tbetf/f-Foxp3YFPCre mice controlled the infection. Tbetf/f-Foxp3YFPCre mice did not control the Th1 mediated inflammation, which lead to immune mediated pathology. Depletion of CD4+ T cells and antibiotic treatment ameliorates morbidity in Tbetf/f-Foxp3YFPCre mice. While loss of Tbet in Tregs lead to higher frequencies and numbers of Tregs, these cells were still unable to prevent lethal immunopathology. RNA-seq analysis reveals that Tbet regulates several key cellular pathways and developmental processes that enhance the Treg’s ability to suppress immune response in a Th1 environment. Taken together, our data highlights an essential role for Tbet in Tregs to prevent lethal immunopathology during acute Toxoplasma gondii infection.
Cigarette smoke has opposite effects in murine models of ulcerative colitis and Crohn’s disease through mucosal immunity and gut environment
Authors: Kitabatake Masahiro , Nishioka Tatsuki , Ouji-Sageshima Noriko , Ito Toshihiro 
Published: January 2023

Abstract
Inflammatory bowel diseases (IBD), comprising ulcerative colitis (UC) and Crohn’s disease (CD), represent chronic intestinal inflammation, and the exact cause of each disease is still unclear. Clinical studies have reported that smoking exacerbates pathogenesis in CD patients, whereas it plays a protective factor in UC patients. However, the mechanism of how smoking has different effects on UC and CD remains unknown.
In this study, C57BL/6 mice were exposed with cigarette smoke (CS; 20 cigarettes/day) for two weeks, and then, mice were administered dextran sodium sulfate (DSS) or tri-nitrobenzene sulfonic acid (TNBS) to induce colitis as UC and CD model, respectively. CS exposure improved the colon inflammation and histological score in UC model, while it worsened them in CD model. In UC model, CS induced regulatory T cells (Tregs) and decreased activated CD8+ T cells. Diversity of gut microbiota was expanded by CS exposure. Interestingly, proportion of Lachnospiraceae, which is thought to generate short chain fatty acid and induce Tregs, was increased. On the other hand, Th1 cells were significantly increased in lamina propria in CD model, and diversity of gut microbiota was decreased and proportion of Enterobacteriaceae, which is considered to associate with onset and enhanced inflammation in IBD, was remarkably increased in CD model. Moreover, one of metabolites induced by CS in UC model improved DSS-induced colitis by increasing Tregs and by decreasing inflammatory cytokines in colon.
These results suggest that CS exposure regulates pathogenesis of IBD by changing gut environment including gut microbiota as well as intestinal immunity.
Olfactory sensory neurons regulate mucosal antiviral immune responses
Authors: Kraus Aurora , Salinas Irene 
Published: January 2023

Abstract
The olfactory mucosa is the first line of defense against respiratory and neurotropic viruses but must balance eradication of virus with the cost of extended inflammation that can itself be deleterious. In bony fish, aquatic rhabdovirus and olfactory sensory neurons (OSNs) directly interact prompting action potentials toward the olfactory bulb (OB) and rapid onset of immune gene transcription and cell infiltration. The presence of viral invaders in the olfactory organ (OO) must be dealt with swiftly to protect the central nervous system (CNS), however, the mechanisms by which OSNs participate in defense are unknown. The goal of this project is to understand the role OSN activation plays in regulating ultra- rapid immune responses to rhabdovirus. I have established a zebrafish model of nasal rhabdoviral infection where intranasal viral delivery causes inflammation and vasodilation in the zebrafish OO in just 15 minutes. Both the OO and OB show little neuronal damage by immunofluorescence of apoptosis markers. In both larval and adult fish OSN activation sends signals to the OB, mediating significant behavioral changes. single cell (sc)RNA-Seq of the OB reveals the onset of a protective state where both microglia and neurons downregulate sensory differentiation factors and innate immune response mediators (cytokines/complement), in the absence of viral translocation. Together these experiments reveal that viral detection by OSNs creates a neuroprotective state in both the OO and OB in minutes. Further work aims to elucidate precise mechanisms by which OSNs are participating in immediate antiviral immunity.
A novel lung DC(3) population potently induces Th17 responses to inhaled allergens
Authors: Cook Donald N , Izumi Gentaro , Karmaus Peer WF , Nakano Hideki 
Published: January 2023

Abstract
Allergic asthma is an inflammatory disease of the airways associated with T helper (Th)2-driven eosinophilia and Th17-directed neutrophilia. Although eosinophilic asthma generally responds well to inhaled glucocorticoids, neutrophilic asthma does not, and new therapies are needed for this disease subtype. A consensus DC subset in the lung that strongly promotes Th17 responses to inhaled allergens has remained elusive, as some groups have reported that CD103+ DCs (DC1) promote Th17 differentiation, whereas other groups have attributed this function to CD11bhi DCs (DC2). We hypothesized that this apparent discrepancy might be due to the heterogeneity of lung CD11b+ DCs and therefore used mass cytometry (CyTOF) to study these cells following allergic sensitization through the airway. We identified a novel CD11b+ APC that was recruited to the inflamed airways of mice following their inhalation of house dust extracts. These cells were bona fide DCs, as they were FLT3L-dependent, expressed Zbtb46, and formed dendrites. Bulk RNA-seq analysis of these DCs revealed that their transcriptome was similar to, yet distinct from, that of conventional DC2s. Although the novel DCs promoted only weak Th2 differentiation, they drove robust Th17 differentiation. Single cell RNA-sequencing of total lung CD11bhi DCs revealed seven distinct clusters, two of which co-expressed both Tgfb1 and Il1b. Pseudotime analysis suggested a progression from an immature form of these cells to a more mature form. Together, these findings identify a novel DC population (DC3) in the lung that potently stimulates Th17 responses to inhaled allergens.
Inhibition of Acute Type-2 Lung Inflammation by 2′3′-cyclic Guanosine Monophosphate-Adenosine Monophosphate (2′3′-cGAMP)
Authors: She Li , Barrera Gema , Yan Liping , Alanazi Hamad , Brooks Edward , Dube Peter , Sun Yilun , Liu Yong , Zhang Nu , zhang Xin , Li Xiao-Dong 
Published: January 2023

Abstract
2′3′-cGAMP is known as a novel non-classical 2nd messenger synthesized by the novel DNA sensor cyclic GMP-AMP synthase (cGAS) in response to cytosolic invasion of DNA-containing microorganisms in mammalian cells. 2′3′-cGAMP possess potent anti-tumor, antiviral and immune adjuvant effects via the STING-mediated signaling pathway. However, its function in modulating type-2 immune responses remains unclear. In this report, we investigated the role of 2′3′-cGAMP in regulating type-2 inflammatory reactions in a mouse model of allergic asthma. We demonstrate that 2′3′-cGAMP strongly inhibits both IL-33 and allergen-driven acute type-2 lung inflammation and airway hyperresponsiveness. Mechanistically, we demonstrate that 2′3′-cGAMP treatment inhibits the proliferation and function of group 2 innate lymphoid cells (ILC2) through an IFNAR1-dependent mechanism. We further show that internalization of 2′3′-cGAMP by alveolar macrophages activates STING-IRF3 signaling to induce the production of IFNα in mouse lungs. Taken together, our results present a proof-of-concept evidence to support a therapeutic value of 2′3′-cGAMP in preventing acute lung inflammation in a mouse model of allergic asthma.
Antifibrotics Modify B-cell Induced Fibroblast Migration and Activation in IPF Patients
Authors: Ali Mohamed , Egan Ashley M , Shaughnessy Gaja F , Dasari Harika , Van Keulen Virginia P. , Aubry Marie Christine , Limper Andrew H , Peikert Tobias , Carmona Eva M 
Published: January 2023

Abstract

Background
Acute respiratory exacerbations in idiopathic pulmonary fibrosis (IPF), often triggered by infection, are life threatening events characterized by rapid deterioration of lung function and associated with poor prognosis. Since microbial antigens modulate immunity by activating different pattern recognition receptors (PRR) expressed by innate immune cells (including B-cells), we sought to investigate how the activation of human B-cells through PRR stimulation by different microbial (CpG and β-glucan) and non-microbial (Mitochondrial DAMPs; MTDs) antigens resulted in the release of an inflammatory/fibrotic milieu that contributed to the pathogenesis of fibrosis in patients with IPF.

Results
Our results show that an inflammatory milieu is induced by stimulating circulating B-cells with both noninfectious (MTDs) and infectious antigens (CpG and β-glucan) commonly found in bacteria and fungi. Moreover, we show that the inflammatory milieu produced was specific to the inducing antigen, and that the microbial antigens (CpG and β-glucan) triggered distinct signaling pathways in B-cells. Specifically, CpG induced mTOR-activation while β-glucan was mTOR-independent and activated Src and p38. Furthermore, our results also show that B-cell aggregates are present within fibrotic areas of the lung in IPF patients and activated B-cells induce fibroblast migration, which was modified by antifibrotics (nintedanib and pirfenidone).

Conclusion
Our results highlight the potential contribution of activated B-cells through PRRs to the proinflammatory and profibrotic milieu seen in patients with idiopathic pulmonary fibrosis.