bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD4 T Cell-autonomous TNF receptor type 2 promotes interleukin-2 transcription (IRM6P.723)
Authors: McKarns Susan , Miller Patrick 
Published: January 2023

Abstract
Interleukin (IL)-2 plays a key role in adjusting the dynamic state of equilibrium between effector T cells (Teffs) and regulatory T cells (Tregs) as well as channeling the outcome of immune responses. IL-2 is mainly produced by activated CD4 T cells and the absence of IL-2 signaling results in lethal autoimmunity. In this study we investigated the role of tumor necrosis factor alpha (TNF) receptors type 1 (TNFR1) and type 2 (TNFR2) on the regulation of IL-2 at the level of transcription during the primary activation of CD4 T cells. We generated TNFR1- and/or TNFR2-deficient-IL-2-GFF knock-in reporter mice to examine Il2 promoter activity at the single cell level. We found that the deficiency of TNFR2, but not TNFR1, markedly diminished the number of CD4 T cells that produced IL-2. We further correlated decreased Il2 transcription with impaired intracellular c-Rel expression in TNFR2 KO CD4 T cells. IL-2 production was augmented in response to the addition of soluble TNF implicating a role for transmembrane TNF (tmTNF). Collectively, these data suggest that CD4 T cell autonomous tmTNF/TNFR2 signaling contributes to the number of IL-2 producers by providing a critical third signal necessary for threshold Il2 promoter activity. These results have important implications for understanding the contribution of IL-2 signaling on the dynamic equilibrium between Teff cells and Treg cells and the outcome of inflammatory immune responses.
Peroxisome proliferator-activated receptor-alpha (PPARα) suppresses T helper 1 (Th1) cytokine production in male mice by inducing post-translational histone modifications at the interferon-gamma (IFNγ) locus (IRM6P.724)
Authors: Zhang Monan Angela , Dunn Shannon 
Published: January 2023

Abstract
Women develop more robust Th1 inflammatory responses than men. Previously, we showed that lower Th1 cytokine responses in males correlated with higher expression of the androgen-sensitive nuclear receptor PPARα, which represses IFNγ production by T cells (Zhang et al. PNAS 2012). The current study aimed to elucidate the molecular mechanism of repression of IFNγ by PPARα in male mouse CD4+ T cells. We first contrasted the expression of various Th-associated genes between anti-CD3 and anti-CD28-stimulated PPARα+/+ (WT) and PPARα-/- (KO) T cells. Of these genes, only T-bet, Eomes, and IFNγ mRNAs were expressed at higher levels in KO vs. WT T cells. Since these genes can reinforce each others’ expression, we further examined their expressions under conditions of either T-bet deficiency or IFNγ neutralization. We found that the higher expressions of T-bet and Eomes were lost, but IFNγ mRNAs remained elevated in KO cells, indicating IFNγ as the likely gene repressed by PPARα. We then performed chromatin immunoprecipitation experiments to examine the abundance of a permissive histone mark (acetylated-H4) and a co-repressor protein (NcoR) at conserved non-coding sequence sites across the ifng locus. We detected global de-repression of ifng in KO vs. WT cells while treating WT cells with a specific agonist induced PPARα recruitment and decreased H4 acetylation at certain sites. Thus, our data suggest that PPARα suppresses IFNγ in males by keeping ifng less poised for transcription.
The RNA-binding protein HuR is required for normal homeostatic control of IL-2 expression in activated CD4 T cells (IRM6P.713)
Authors: Techasintana Patsharaporn , Magee Joseph , Atasoy Ulus 
Published: January 2023

Abstract
Upon T cell activation approximately 50% of genes are regulated at the posttranscriptional level by RNA-binding proteins (RBPs). HuR is a stabilizing RBP which regulates mRNA via interactions with AU-rich elements (ARE) in mRNA 3’UTRs. HuR has been shown to be crucial for T cell development, thymic selection and egression. However, it is unclear how HuR regulates T cell differentiation and cytokine expression. To further investigate these questions, we generated a novel conditional HuR KO mouse, distal-Lck Cre ROSA HuRfl/fl which ablates HuR in mature T cells prior to activation. HuR KO T cells develop and egress from thymus normally; however, they display aberrant cytokine and receptor expression upon activation. Activated HuR KO T cells show striking increases in IL-2 (20-30 fold) and display an inability to turn off IL-2 expression, but significant decreases in IL-4, IL-5 and IL-13 with no change in IFN-γ. Over 90% of HuR KO CD4 cells still make IL-2 five days after activation but display impaired IL-4, IL-5 and IL-13 secretion. Increases in IL-2 in HuR KO cells are due to augmentation of IL-2 transcription and mRNA stability. Moreover, there are significant decreases in proliferation and CD25 (IL-2Rα) expression in HuR KO cells as a result of reductions in CD25 transcription. Thus, HuR is required for cytokine homeostasis in CD4 cells and may well function as a critical off-switch for IL-2 expression during T cell activation.
β-catenin promotes colitis and colon cancer through imprinting of pro-inflammatory properties in T-cells. (LYM3P.727)
Authors: Keerthivasan Shilpa , Aghajani Katayoun , Dose Marei , Khazaie Khashayarsha , Gounari Fotini 
Published: January 2023

Abstract
The density and type of lymphocytes infiltrating colon tumors are predictive of the clinical outcome of colon cancer. High densities of TH17 cells and inflammation predict poor outcome, while infiltration by T regulatory cells (Tregs) that naturally suppress inflammation is associated with longer patient survival. However, the role of Tregs in cancer remains controversial. We previously reported that Tregs in colon cancer patients can become pro-inflammatory and tumor promoting. These properties were directly linked with their expression of RORγt, the signature transcription factor of TH17 cells. Here, we report that Wnt/β-catenin signaling in T-cells promotes expression of RORγt. Expression of β-catenin was elevated in T-cells, including Tregs, of patients with colon cancer. Genetically engineered activation of β-catenin in mouse T-cells resulted in enhanced chromatin accessibility in the proximity of Tcf-1 binding sites genome-wide, induced expression of TH17 signature genes including RORγt, and promoted TH17-mediated inflammation. Strikingly, the mice had inflammation of small-intestine and colon and developed lesions indistinguishable from colitis-induced cancer. Activation of β-catenin only in Tregs was sufficient to produce inflammation and initiate cancer. Based on these findings we conclude that activation of Wnt/β-catenin signaling in effector T-cells and/or Tregs is causatively linked with the imprinting of pro-inflammatory properties and promotion of colon cancer.
Deep sequencing of the gag-specific CD4+ T cell receptor repertoire and CD4+ memory subsets of HIV viral controllers reveals significant sharing of unique gag-specific TCRs in central and effector memory TCR repertoires (LYM3P.742)
Authors: Pilkinton Mark , Barnett Louise , Kalams Spyros 
Published: January 2023

Abstract
HIV viral controllers maintain preserved CD4+ T cells counts and undetectable viral levels off antiretroviral therapy. The diversity of the HIV-specific T cell receptor (TCR) repertoire within memory may be important for maintaining viral control, however, sequencing the entire CD4+ memory repertoire to evaluate for HIV specific TCRs would be prohibitive by conventional methods. In this study, the TCR repertoire of two HIV controllers was analyzed with deep sequencing. Peripheral blood mononuclear cells (PBMC) of HIV+ individuals were stimulated by Gag peptides and the Gag-specific CD4+ T cells were sorted by expression of the activation markers. Unstimulated PBMC were sorted for CD4+ memory subsets based on central memory (CD45RO+CCR7+), effector memory (CD45RO+CCR7-), and naïve (CD45RO-CCR7+). Subject 1 had 46 Gag-specific CD4+ TCR. 18 were in the Tcm population and 24 in the Tem population, though 15 of these sequences were identified in both subsets. In Subject 2, there were 29 Gag-specific TCR with 27 in the Tcm population and 20 in the Tem repertoire with 20 Gag-specific TCR identified in both populations. Deep sequencing of the HIV specific TCR repertoire and unbiased memory subsets revealed a high degree of overlap of CD4+ HIV-specific cells in both the Tcm and Tem populations. Further studies will need to be performed to determine if this provides an advantage for virologic control.
Harnessing the heterogeneity of T cell differentiation fate to fine-tune generation of effector and memory T cells (LYM4P.759)
Authors: Gong Chang , Linderman Jennifer , Kirschner Denise 
Published: January 2023

Abstract
Recent studies show that naïve T cells bearing identical T cell receptors experience heterogeneous differentiation and clonal expansion processes. The factors controlling this outcome are not well characterized, and their contributions to immune cell dynamics are similarly poorly understood. In this study, we develop a computational model to elaborate mechanisms occurring within and between two important physiological compartments, lymph nodes and blood, to determine how immune cell dynamics are controlled. Our multi-organ (multi-compartment) model integrates cellular and tissue level events and allows us to examine the heterogeneous differentiation of individual precursor cognate naïve T cells to generate both effector and memory T lymphocytes. Using this model, we simulate a hypothetical immune response and reproduce both primary and recall responses to infection. Increased numbers of antigen-bearing dendritic cells are predicted to raise production of both effector and memory T cells, and distinct “sweet spots” of peptide-MHC levels on those dendritic cells exist that favor CD4+ or CD8+ T cell differentiation towards either effector or memory cell phenotypes. This has important implications for vaccine development and immunotherapy.
Probiotic lactobacillus ameliorates heightened colonic inflammatory responses in infected stressor-exposed C57BL/6 mice and inhibits dysbiosis (MPF1P.771)
Authors: Galley Jeff , Mackos Amy , Parry Nicola , Yu Zhongtang , Ahmer Brian , Bailey Michael 
Published: January 2023

Abstract
The mammalian colon is a primary niche for the microbiota, a community of bacteria in part involved in immune maintenance. Alterations in these microbial populations, referred to as dysbiosis, can have deleterious effects on host health and previous studies show psychological stress can lead to dysbiosis. We investigated if stressor exposure could increase the severity of colonic infection with the enteric pathogen, Citrobacter rodentium. Mice that were subjected to social stressor exposure had increases in pathogen burden and the inflammation-related gene transcripts TNF-alpha, iNOS, and CCL2. The stressor-exposed mice also had increased colitic pathology. When mice were treated with a probiotic strain of Lactobacillus reuteri, the colitic pathology and resultant inflammatory markers were abrogated. The mechanism by which L. reuteri reduces colitis is unknown. Probiotic treatment of germ-free mice mono-associated with C. rodentium did not reduce inflammation, indicating that direct immune intervention is unlikely. However, quantitative PCR of conventional mice infected with C. rodentium revealed that stressor-exposed mice had altered levels of commensal microbes, and probiotic treatment caused these populations to rebound. Thus, stressor exposure exacerbated infection-induced dysbiosis and colonic inflammation. It is proposed that probiotic treatment prevents stressor-induced exacerbation of colonic inflammation by preventing dysbiosis.
IL-1α is critical for leukocyte recruitment during pulmonary Aspergillus fumigatus infection (MPF1P.776)
Authors: Caffrey Alayna , Lehmann Margaret , Shepardson Kelly , Watschke Christopher , Hilmer Kimberly , Zickovich Julianne , Barker Bridget , Cramer Robert , Obar Joshua 
Published: January 2023

Abstract
Aspergillus fumigatus is a mold that causes severe pulmonary infections. Currently, our knowledge of how A. fumigatus growth is controlled in the respiratory tract is limited. Alveolar macrophages and the airway epithelial cells constitute the first lines of defense against inhaled A. fumigatus conidia; subsequently, neutrophils and macrophages are sequentially recruited to the respiratory tract to control fungal growth and germination. How neutrophils and macrophages are recruited to the respiratory tract after A. fumigatus infection remains ill defined. A. fumigatus instillation induced biphasic expression of the inflammasome-dependent cytokines IL-1β and IL-18 during the first 48 hours, while IL-1α expression linearly grew over the same period. Il1r1-deficient mice are highly susceptible to pulmonary A. fumigatus infection. Enhanced susceptibility of Il1r1-deficient mice correlated with defects in leukocyte recruitment and anti-fungal activity. Interestingly, IL-1α rather than IL-1β was crucial for optimal leukocyte recruitment. IL-1α signaling enhanced the production of CXCL1, which was responsible for pulmonary leukocyte recruitment. In contrast, the inflammasome and IL-1β was only essential for optimal activation of anti-fungal activity of leukocytes. As such, Pycard-deficient mice were only mildly susceptible to A. fumigatus infection. Taken together, our data reveal central, non-redundant roles for IL-1α and IL-1β in controlling A. fumigatus infection in the lung.
Basic leucine zipper transcription factor, ATF-like (BATF) is essential for the development of protective immunity against parasitic helminth infection (MPF1P.779)
Authors: Bao Katherine , Reinhardt Richard 
Published: January 2023

Abstract
Parasitic helminth infections afflict roughly a quarter of the world’s population. Immunity against parasitic helminth infection relies on the induction of allergic inflammation. Major hallmarks of allergic inflammation, such as IgE, eosinophilia, and mucus production, depend on the cytokines interleukin-4 (IL-4) and IL-13. In mice, IL-4 from CD4+ follicular T helper (Tfh) cells is required for IgE production, while IL-13 from CD4+ T-helper 2 (Th2) cells is required for worm clearance and mucus production. The basic leucine zipper transcription factor, ATF-like (BATF) is critical for Tfh function, however its necessity in Th2 cell development and IL-4 production remains unclear. To investigate the role of BATF in the context of allergic inflammation, we infected wild-type and BATF-deficient mice with the helminth Nippostrongylus brasiliensis to compare the resultant immune responses. In wild-type mice, N. brasiliensis infection induced a robust response as indicated by lung eosinophilia, high serum IgE, and worm expulsion. In contrast, BATF-deficient mice exhibited dramatically reduced eosinophilia, no IgE, and were unable to clear parasites from the intestine. Studies with IL-4-reporter mice revealed that these defects in allergic immunity were attributed to impaired Tfh and Th2 cell development. These findings suggest that BATF plays a central role in protection against helminths, and BATF is critical for the development of both Th2 and Tfh cells during allergic responses.
Interleukin-3-deficient mice have increased resistance to blood-stage malaria (MPF1P.764)
Authors: Auclair Sarah , Roth Kenneth , Saunders Bryan , Ogborn Kathryn , Sheikh Abdalla , Naples Julianne , Young Anna Marie , Boisen Dorottya , Tavangar Amelia , Welch Jane , Lantz Chris 
Published: January 2023

Abstract
The contribution of interleukin-3 (IL-3), a hematopoietic growth factor and immunoregulatory cytokine, to resistance to blood-stage malaria was investigated by infecting IL-3 deficient (knockout [KO]) mice with Plasmodium berghei NK65. Male IL-3 KO mice, but not female mice, were more resistant to infection than wild-type (WT) mice, evidenced by lower peak parasitemia and prolonged survival. Both male and female IL-3 KO mice had increased splenomegaly and were more anemic than corresponding WT mice. Anemia was compensated for by an increase in bone marrow and splenic erythropoiesis in IL-3 KO mice, as evidenced by higher levels of erythroid progenitors. Plasma levels of gamma interferon (IFN-γ) and CXCL9 (Monokine Induced by IFN-γ; [MIG]) were found to be significantly reduced in IL-3 KO mice during early stages of infection whereas G-CSF levels were significantly greater than in WT counterparts. Overall, our results indicate that IL-3 plays a critical role in suppressing protective immunity to P. berghei NK65 infection and that it is involved in inhibiting the development of splenomegaly, anemia, and erythropoiesis. IL-3 also influences IFN-γ, CXCL9, and G-CSF production in response to infection. The abnormal responses seen in infected IL-3 KO mice may be due to the lack of IL-3 during development, to the lack of IL-3 in the infected mature mice, or to both.
Influenza infection suppresses NADPH oxidase-dependent phagocytic bacterial clearance and enhances susceptibility to secondary MRSA infection (MPF2P.811)
Authors: Sun Keer , Metzger Dennis 
Published: January 2023

Abstract
Methicillin-resistant S. aureus (MRSA) has emerged as a leading contributor to mortality during recent influenza pandemics. The mechanism for this influenza-induced susceptibility to secondary S. aureus infection is poorly understood. Here we show that innate antibacterial immunity was significantly suppressed during the recovery stage of influenza infection, despite the fact that MRSA super-infection had no significant effect on viral burdens. Compared to mice infected with bacteria alone, post-influenza MRSA infected mice exhibited impaired bacterial clearance, which was not due to defective phagocyte recruitment, but rather coincided with reduced intracellular reactive oxygen species (ROS) levels in alveolar macrophages and neutrophils. NADPH oxidase is responsible for ROS production during phagocytic bacterial killing, a process also known as oxidative burst. gp91phox-containing NADPH oxidase activity in macrophages and neutrophils is essential for optimal bacterial clearance during respiratory MRSA infections. In contrast to WT animals, gp91phox-/- mice exhibited similar defects in MRSA clearance before and after influenza infection. Using gp91phox+/- mosaic mice, we further demonstrate that influenza infection inhibits a cell-intrinsic contribution of NADPH oxidase to phagocyte bactericidal activity. Together, our results establish that influenza infection suppresses NADPH oxidase-dependent bacterial clearance and leads to susceptibility to secondary MRSA infection.
Increased CD4 and CD206 expression in a rich environment of IL-4 and IFN-γ in fatal cases of coccidiodomycosis (MPF2P.813)
Authors: Rosas-Taraco Adrian , Rodriguez-Ramirez Heidi , Barboza-Quintana Oralia , Ceceñas-Falcon Luis , Gonzalez Gloria , Salinas-Carmona Mario 
Published: January 2023

Abstract
Coccidioidomycosis is a fungal disease caused by Coccidioides immitis or Coccidioides posadasii. Little is known about the immunological environment in human lung of fatal cases. The aim of this study was to analyze inflammatory and anti-inflammatory cytokine expression (IL-4, IL-10, IL-17, and IFN-γ), as well as, CD4 (T helper, Th), CD8 (T cytotoxic, Tc), FOXP3 (Regulatory T cell), and CD206 (alternatively activated macrophage, AAM) markers in human lung tissue from fatal cases of coccidioidomycosis. A total of five biological samples from fatal cases and five controls were included in this study. Paraffin embedded blocks were cut in sections and prepared for immunohistochemistry (IHC) for each cytokine or cell marker. No differences were found in IL-10 and IL-17 expression, however, high levels of IL-4 and IFN-γ were found in lung of fatal cases of coccidioidomycosis (P&lt;0.05). CD4+ and CD206+ cell markers were elevated in coccidioidomycosis samples when compared with control (P&lt;0.05). In conclusion, our data suggest that AAM/Th2 and Th1 environment co-exists in fatal cases of coccidioidomycosis.
Chlamydia muridarum used in the mouse model of C. trachomatis, contains multiple variants that lead to differential immune responses and disease development. (MPF2P.807)
Authors: Sullivan Jeanne , Frazer Lauren , Darville Toni , O'Connell Catherine 
Published: January 2023

Abstract
C. muridarum Nigg is commonly used in the mouse model of C. trachomatis genital tract infection. Plaque-purified isolates derived from a C. muridarum Nigg stock were compared in the murine model of genital tract infection. C57BL/6 mice were intravaginally infected with strains CM001, CM002, CM005, CM006, CM012, or the parental AR Nigg and differences in infection course and disease outcome were observed. We identified CM001 as hyper-virulent because infection course in the lower tract was extended, bacterial load was elevated (P=0.02) and we observed increased frequency of hydrosalpinx (P&lt;0.01) and oviduct dilatation scores when compared to AR Nigg. CM012 was attenuated, with reduced lower genital tract course of infection (P=0.05), decreased pyosalpinx early, and decreased hydrosalpinx (P&lt;0.001) and oviduct dilatation (P&lt;0.01) at resolution. Infection with CM002, CM005, and CM006 yielded similar bacterial burden and oviduct pathology to the parental stock. Inoculation of immune deficient mice revealed that infection with CM001 resulted in the death of rag1-/- mice in contrast to both CM012 and AR Nigg, which established chronic infections. Furthermore, CM001 caused enhanced oviduct pathology in tlr2-/- mice compared with AR Nigg while CM012 infection resulted in even milder pathology than the parent. Importantly, differences between chlamydial strains used for animal modeling of human disease should be considered as a cause for observed differences in disease phenotype.
Vaccine mediates protection against penicilliosis in BALB/c mice (MPF2P.810)
Authors: Yang Fengjuan , Yuen Kwok-Yung , Lau Susanna KP , Woo Patrick CY 
Published: January 2023

Abstract
Dimorphic pathogenic fungus Penicillium marneffei can cause penicilliosis which is a common infectious disease in AIDS patients in Southeast Asia and southern parts of China. Mp1p is a highly antigenic cell wall mannoprotein encoded by MP1 gene of P. marneffei and it is a pivotal factor for the pathogen infection and survival. Recombinant protein Mp1p produced in E.coli and Pichia pastors was used as an antigen vaccine against penicilliosis. While administered with different adjuvants and injection routes to BALB/c mice, this vaccine protein combination with Sigma Adjuvant System by intraperitoneal injection elicited a strong immunoglobulin G antibody response and conferred protection against a lethal P. marneffei challenge. These results showed that protein Mp1p could protect BALB/c mice in a dose, adjuvant and injection dependent manner. Protein vaccine Mp1p induced resistance was assessed in terms of survival, fungal growth (CFU) and histopathological examination. Immunised BALB/c mice could be protected against P. marneffei with 100% survival. CFU and histopathological analysis implied that fungal growth was systemically restricted at target organ of vaccinated mice, especially in liver where there was a significant lower value of CFU than non-vaccinated mice. Our results support the further development of an effective vaccine against penicilliosis.