bluuebunny/crossref_metadata_2025_split huggingface dataset:
An essential role of transcription factors PU.1 and IRF8 in follicular B cell development and the germinal center response
Authors: Wang Hongsheng , Jain Shweta , Sun Jiafang , Kovalchuk Alexander L. , Morse Herbert C. 
Published: January 2023

Abstract
The transcription factors PU.1 and IRF8 regulate an unknown number of gene programs for differentiation of many hematopoietic cells including B cells, dendritic cells and myeloid cells. Their roles in B cell development were previously studied using B cell-specific conditional deletion mouse models, such as PU.1flox/flox-CD19Cre, IRF8flox/flox-CD19Cre, IRF8−/−PU.1flox/flox-CD19Cre, or IRF8flox/flox-PU.1flox/flox-CD19Cre mice. While PU.1-deficient B cells are phenotypically normal, deletion of IRF8 in B cells caused a moderate expansion of marginal zone B cells. Double deletion of PU.1 and IRF8 caused moderate expansion of plasma cells (PCs) in vitro. In this report, we investigated IRF8 and PU.1 double deletion mice using Mb1-Cre - termed DKO mice. FACS analysis revealed normal levels of early stage B cells in the bone marrow and transitional B cells in the spleens of DKO mice. However, follicular B cells were markedly reduced and the MZ B cell compartment was modestly expanded in DKO mice. The peritoneal CD5+ B-1a cells, which are a major source of circulating IgM, were completely absent in DKO mice. Surprisingly, the serum levels of IgM were higher and the levels of IgG3 and IgA were slightly lower in DKO than control mice. While the levels of serum IgG1 were comparable between DKO and control mice, DKO mice had no serum IgG2b or IgG2c antibodies. More intriguingly, following immunization with NP-KLH/alum, although the DKO mice produced more IgM-secreting PCs early on, they failed to generate germinal centers and produced markedly reduced levels of NP-specific switched IgG antibodies. Taken together, these data revealed a critical role of IRF8 and PU.1 in differentiation of follicular and germinal center B cells.
Progressive upregulation of oxidative metabolism facilitates plasmablast differentiation to a T-independent antigen
Authors: Price Madeline J. , Patterson Dillon , Scharer Christopher D. , Boss Jeremy M. 
Published: January 2023

Abstract
Transitioning from a metabolically quiescent naïve B cell to an antibody-secreting plasmablast requires division-dependent cellular differentiation. Though cellular processes such as cell division and antibody secretion demand significant ATP and metabolites, the metabolic processes used to generate ATP during plasmablast formation are not well described. Here, the metabolic machinery requirements for plasmablast formation were determined. Following T-independent stimulation with lipopolysaccharide, B cells increased expression of the oxidative phosphorylation machinery in a step-wise manner. Such activated B cells have increased capacity to perform oxidative phosphorylation, but showed additional dependency on glycolytic metabolism. Plasmablasts displayed higher oxidative metabolism to support antibody secretion, as inhibiting oxidative ATP production with oligomycin resulted in decreased antibody titres. Differentiation orchestrated by Blimp1 was required for this increase in oxidative metabolism as Blimp1-deficient cells proliferate normally, but neither differentiate to plasmablasts nor upregulate oxidative phosphorylation. Therefore, Blimp1 expression is required for full metabolic activity, and proliferation alone is insufficient to induce full oxidative phosphorylation. Together, these findings identify a shift in metabolic pathways as B cells differentiate, as well as the requirement for increased metabolic potential to support antibody production.
The histone demethylase LSD1 regulates B cell proliferation and plasmablast differentiation
Authors: Haines Robert Richard , Barwick Benjamin G. , Majumder Parimal , Scharer Christopher D. , Boss Jeremy M. 
Published: January 2023

Abstract
In order to generate humoral immunity, B cells must differentiate into antibody-secreting cells in response to antigen. LSD1 is a histone demethylase that regulates multiple cellular differentiation pathways and has been implicated to function during B cell differentiation through interaction with Blimp-1. Here we show that LSD1 is necessary for maximal proliferation and differentiation of naïve B cells into LPS-induced plasmablasts. LSD1-deficient B cell differentiation results in the targeted upregulation of hundreds of genes, a subset being Blimp-1 repressed genes, as well as the targeted downregulation of cell cycle genes. Plasmablasts lacking LSD1 fail to close chromatin at naïve B cell active enhancers in addition to PU.1 and IRF4 binding sites. LSD1 directly regulates the Blimp-1 target gene Sell through H3K4me1 demethylation at its Blimp-1 target binding sites. Our data defines LSD1 as a critical transcriptional and epigenetic repressor in plasmablasts.
Defining the mechanism of BATF specificity in Th cell lineages
Authors: Fu Yongyao , Kaplan Mark H. 
Published: January 2023

Abstract
IL-9 is a pleiotropic cytokine produced by Th9 cells and inappropriate expression is associated with immune disorders. The basic leucine zipper transcription factor (BATF) is expressed in multiple Th subsets and cooperates with other factors to regulate gene transcription. BATF-deficiency results in diminished IL-9 in Th9 cells and decreased IL-17 in Th17 cells. However, ectopic expression of BATF activates only the lineage-specific cytokine; IL-9 in Th9 cells and IL-17 in Th17 cells. The mechanism for this restricted activity is unclear. In this study, we demonstrate a lineage specific mechanism of how BATF activates Il9 in Th9 and Th17 cells. Using ChIP and chromatin accessibility assays we found that BATF binds to the Il9 gene locus at a greater level in Th9 cells compared to Th17 cells. This observation may be because the DNA in Th17 cells is in a heterochromatic state. Increasing the chromatin accessibility of Il9 gene locus in Th17 cells followed by BATF overexpression leads to increased IL-9 production. BATF forms a heterodimer with Jun family members to induce gene expression. The expression level of c-Jun and JunB in Th17 cells is lower compared to Th9 cells. In testing the role of these factors, we observed that the loss of c-Jun or JunB impairs IL-9 production in Th9 cells, indicating that Jun family members promote IL-9 production. Ectopic expression of BATF with either c-Jun or JunB significantly increases IL-9 production in Th17 cells, suggesting the low expression of Jun family members limits the ability of BATF to induce IL-9 in Th17 cells. Taken together, our results reveal a mechanism for how BATF achieves specificity of cytokine induction in Th subsets.
The plasma kallikrein-kininogen pathway is critical in the pathogenesis of colitis in mice
Authors: Wu Yi 
Published: January 2023

Abstract
The kallikrein-kinin system (KKS) consists of two serine proteases, prekallikrein (pKal) and factor XII (FXII), and a cofactor, high-molecular-weight kininogen (HK). Although the KKS is activated in humans and animals with inflammatory bowel disease (IBD), its role in the pathogenesis of IBS has not been characterized. Here we determined the role of the KKS in the pathogenesis of IBD using mice that lack proteins involved in the KKS. In two colitis models, induced by dextran sulfate sodium (DSS) or 2,4,6-trinitrobenzene sulfonic acid (TNBS), mice deficient in HK, pKal, or bradykinin receptors displayed attenuated phenotypes including body weight loss, disease activity index, colon length shortening, reduced histological scoring, and increased colonic production of cytokines. Infiltration of neutrophils and inflammatory monocytes in the colonic lamina propria was reduced in HK-deficient mice. Reconstitution of HK-deficient mice through intravenous injection of HK recovered their susceptibility to DSS-induced colitis, increased IL-1β levels in the colon tissue, and bradykinin concentrations in plasma. In contrast to the phenotypes of other mice lacking other proteins involved in the KSS, mice lacking FXII had comparable colonic inflammation to that observed in wild-type mice. The concentration of bradykinin was significantly increased in the plasma of wild-type mice after DSS-induced colitis. In vitro DSS-induced pKal activation, HK cleavage, and bradykinin plasma release were prevented by the absence of pKal or the inhibition of Kal. Unlike DSS, TNBS-induced colitis did not trigger HK cleavage. Collectively, our data strongly suggests that Kal contributes to experimental colitis by promoting bradykinin release from HK.
Enterohepatic Helicobacter species modulate severity of DSS-induced colitis but do not prevent amelioration by indole-3-carbinol
Authors: Alkarkoushi Rasha Raheem , Singh Udai P. , Chatzistamou Ioulia , Bam Marpe , Nagarkatti Prakash S. , Nagarkatti Mitzi , Testerman Traci L. 
Published: January 2023

Abstract
Enterohepatic Helicobacter (EHH) species are bacteria that colonize the colons and biliary ducts of humans and other mammals. Virtually nothing is known about the mechanisms of EHH-induced colitis in wild-type mice or humans. Indole-3-carbinol (I3C), a chemical extracted from cruciferous vegetables, ameliorates Dextran sulfate sodium (DSS)-induced colitis. We hypothesized that specific EHH species would alter the course of DSS-induced colitis and possibly the responses to I3C treatment. We infected C57BL/6 mice with human- and rodent-associated EHH species and measured the effects on DSS-induced colitis and response to I3C treatment. We found that H. muridarum(H.m) and H. cinaedi exacerbate DSS-induced colitis and delay recovery. Furthermore, I3C ameliorated colitis and shifted the Treg/Th17 balance in H.m-infected mice. Moreover, the microRNAs expression pattern was altered in H.m-infected mice when compared to that of uninfected mice. Interestingly, enhanced colitis, as well as increased Th17 cells in spleens and mesenteric lymph nodes, were observed in H.m-infected DSS-treated mice(DHM). I3C treatment of DSS + H.m-infected mice (DMI) decreased the expression of pro-inflammatory IL17 and RORC as well as increased anti-inflammatory Foxp3 when compared to DHM group. These immunological changes correlated with the microRNAs expression. This demonstrates that the presence of EHH species alters susceptibility to DSS-induced colitis. Importantly, mice with exacerbated colitis respond to I3C. In the future, we plan to study the mechanisms underlying the effects of EHH on colon cancer development and the efficacy of I3C in both the colitis and colon cancer models.
Increased levels of Th1-inducing cytokines are detected in cervical secretions of women with Chlamydia trachomatis infection limited to their cervix
Authors: Lee De’Ashia E. , Zhong WuJuan , Dong Li , Russell Ali Russell , O’Connell Catherine , Wiesenfeld Harold , Hillier Sharon , Sempowski Gregory D. , Zheng Xiaojing , Darville Toni 
Published: January 2023

Abstract

Background
Chlamydia trachomatis (CT) is the leading bacterial sexually transmitted infection worldwide. CT can ascend to the upper reproductive tract in women, and cause tissue damage resulting in reproductive sequalae. Data from animal and human studies indicate a role for the Th1 cytokine, IFNγ, in protection from infection and disease.

Methods
We recruited 246 women at high risk for CT infection. Cervical swabs and endometrial biopsies were collected for detection of sexually transmitted pathogens, including CT, by nucleic acid amplification test (NAAT). Cervical secretions collected using cervical sponges were screened for 57 cytokines using multiplex bead arrays. Data were analyzed by logistic regression.

Results
92 (37%) women were NAAT+ for CT in only their cervix and 69 (28%) women had CT infection detected at both their cervix and endometrium. Compared to women with endometrial infection, women with only cervical infection had higher levels of CX3CL1 (p&lt;0.05), a potent chemoattractant of T cells and monocytes; CXCL14 (p&lt;0.01), a chemoattractant and activator of dendritic cells, monocytes, and NK cells; and the Th1 inducing cytokine IL-12p70 (p=0.07). Conversely, type I IFN-inducible proteins CXCL9 (p&lt;0.05) and CXCL10 (p&lt;0.01) were significantly increased in women with endometrial infection, compared to women with cervical infection only.

Conclusions
Th1-associated cytokines in cervical secretions are associated with limitation of infection to the cervix, whereas type I IFN-associated chemokines are associated with endometrial CT infection. These proteins may be used as biomarkers to identify women at increased risk for upper reproductive tract pathology and those who could benefit from enhanced screening.
Intestine-specific CCR10+ plasma cells regulate migration of intestinal regulatory T cells
Authors: Zhao Luming , Hu Shaomin , Davila Micha L. , Xiong Na 
Published: January 2023

Abstract
In intestines, B cells are activated in gut-associated lymphoid tissue (GALT) to differentiate predominantly to IgA antibody-secreting cells (IgA-ASCs), which acquire a CCR10+ specific gut-homing property and migrate into intestinal lamina propria where they secrete IgA antibodies specifically acting on commensal bacteria and food-borne antigens for homeostatic regulation. While IgA antibodies were extensively investigated, differentiation of B cells and their functional mechanisms in establishment of intestinal homeostasis are still incompletely understood. We herein report a novel process in which CCR10+ differentiated B cells regulate intestinal homeostasis. We found that CCR10+ IgA-ASCs preferentially interact with activated regulatory T (Treg) cells in GALT and lamina propria to help their localization in colons. In CCR10-knockout mice, defective intestinal migration of IgA-ASCs resulted in reduced Treg cells and spontaneous development of inflammatory symptoms in colons. In addition, in IgA-deficient mice, there was preferential compensatory generation of CCR10+ IgG-ASCs that substituted CCR10+ IgA-ASCs to promote T cell homeostasis and regulate commensal bacteria in colons. The preferential compensatory generation of CCR10+ IgG-ASCs was also observed in IgA-deficient patients. These findings aid our understanding of B cell differentiation and functional mechanisms in intestinal homeostatic regulation.
Phosphorescence-optimized 2-photon lifetime and kinetic imaging reveals reanimation of tumor immune surveillance by hyper-oxygenation
Authors: Rytelewski Mateusz , Harutyunyan Karine , Wspanialy Patrick , Nwajei Felix , Zal Malgorzata Anna , Vinogradov Sergei , Konopleva Marina , Zal Tomasz 
Published: January 2023

Abstract
Lymphocytes encounter varying oxygen levels as they traverse through healthy and diseased tissue. Hypoxia is a hallmark of the tumor microenvironment and can affect the anti-tumor immune response. However, despite the importance of T cell adaptation to differing oxygen concentrations in the tumor niche, there has been no method to study T cell spatiotemporal dynamics in the context of oxygen in vivo. To this end, we developed phosphorescence-optimized 2-photon lifetime and kinetic (2pOLAK) microscopy which enables co-imaging of phosphorescence lifetimes and cellular dynamics in highly fluorescent biological reporter systems. In conjunction with the PtP-C343 oxygen probe, 2pOLAK microscopy revealed the tissue oxygen landscapes and individual oxygen “experiences” of T cells as they moved through tissues in syngeneic models of metastatic lung cancer and acute leukemia. We found that T cells experienced hypoxia in leukemic bone marrow, and that the motility of these cells was significantly decreased relative to non-hypoxic T-cells in healthy bone marrow. Inhibition of oxidative phosphorylation slowed non-hypoxic T cell motility to a level comparable with that of hypoxic T cells. T cell motility was also decreased in hypoxic lung tumor cores, and it was significantly lower than in the tumor margin, where T cells experienced higher oxygen. Supplemental oxygenation increased the oxygen experienced by T cells in the tumor core and reanimated T cell motility. These studies describe a novel method for co-imaging tissue oxygen and cellular behavior, shed light on the role that oxygen availability plays in T cell dynamics in vivo, and suggest that counteracting hypoxia can improve tumor immune surveillance by restarting T cell motility.
Interaction between Kynurenine and the AhR is an effector mechanism of tumor immunosuppression and represents a potential immunotherapy target
Authors: Campesato Luis Felipe , Budhu Sadna , Tchaicha Jeremy , Pourpe Stephane , Liu Cailian , Manfredi Mark G. , McGovern Karen , Wolchok Jedd D. , Merghoub Taha 
Published: January 2023

Abstract
Although with notable impact on cancer treatment, immune-checkpoint blockade (ICB) have multiple mechanisms of resistance. The catabolism of Tryptophan into metabolites known as Kynurenines (Kyn) by enzymes such as IDO or TDO plays a major suppressive role in different tumor types. Recently it was shown that Kyn acts as an endogenous agonist of the Aryl-hydrocarbon Receptor (AhR). In order to gain a better understanding of this pathway, we sought to characterize the mechanisms of immunosuppression associated with AhR and evaluate its potential as therapeutic target. Gene-expression analysis of IDO-overexpressing melanomas (B16-IDO vs B16-WT) present reduced expression levels of Type-1 inflammatory genes, including IFNy, TNFa, Granzyme B and CD40. In addition, B16-IDO presents higher infiltration of TAMs, which up-regulate classic AhR-regulated genes (Cyp1a1 and Cyp1b1) and are differentially skewed towards an immunosuppressive M2-phenotype. Tumor-antigen specific CD8+T cells present reduced expression of activation markers (GzmB and CD44) and proliferation rate when primed by Kyn-treated BMDMs. Also, B16-IDO TAMs suppressed activation of CD8+T cells in vitro and their depletion abrogated tumor growth. Implantation of B16-IDOs in FoxP3-depleted mice prevents TAMs accumulation. Treatment of B16-IDO tumors with an AhR-specific antagonist (CH-223191) up-regulates MHC II in APCs, activation markers in CD8s and reduced frequency of T-regs. AhR inhibition slows down tumor growth and prolongs survival, which is improved in combination with PD-1 blockade. In summary, our findings demonstrate that targeting the Kyn pathway through AhR-inhibition represents a promising approach in cancer patients who are resistant to ICB.
Rapamycin prevents surgery-induced T cell exhaustion in patients with bladder cancer
Authors: Svatek Robert S. , Ji Niannian , Mukherjee Neelam , de Leon Essel , Kabra Aashish , Hurez Vincent , Nicolas Marlo , Michalek Joel E. , Javors Martin , Livi Carolina , Sharp Z. Dave , Curiel Tyler J. 
Published: January 2023

Abstract
The mechanistic target of rapamycin (mTOR) integrates environmental inputs to regulate cellular growth and metabolism in tumors. However, mTOR also regulates T cell differentiation and activation, rendering applications of mTOR inhibitors towards treating cancer complex. Recent preclinical data supports distinct biphasic effects of rapamycin with higher doses directly suppressing tumor cell growth and lower doses enhancing T cell immunity. We conducted a randomized controlled pre-surgical clinical trial to study the tumor and immune effects of low dose mTOR complex 1 inhibition with rapamycin for patients with invasive, non-metastatic bladder cancer. At 3 mg daily for four weeks, rapamycin significantly inhibited tumor mTORC1 (ribosomal protein S6 phosphorylation), and achieved high bladder tissue levels. Rapamycin also reduced surgery-mediated T cell exhaustion, evidenced by a significant decrease in the prevalence of dysfunctional programmed death-1 (PD-1) expressing circulating T cells without decreasing T cell proliferation or cytokine production. In mice challenged with MB49 orthotopic bladder tumors, a 2 cm surgical laparotomy reduces the efficacy of α-PD-L1 immunotherapy but efficacy can be partly restored with presurgical administration of rapamycin. These findings support favorable delivery, pharmacodynamic activity, and immune modulatory profile of low dose rapamycin in bladder cancer and identifies a novel role for mTOR inhibition in modulating surgery-induced immune dysfunction.
Crosstalk of sphingolipids and inflammasomes modulates tumor microenvironment and promotes cancer progression
Authors: Guo Beichu , Kantono Melvin , Sun Wei , Ogretmen Besim 
Published: January 2023

Abstract
Sphingosine-1-phosphate (S1P), a bioactive lipid, plays important roles in tumor development through its ability to promote tumor cell growth, migration, and invasion. S1P, synthesized by sphingosine kinase 1 and 2 (SK1 and SK2), can initiate multiple signal events through intracellular and extracellular mechanisms. In human cancer patients, increased levels of S1P and SK1 are correlated with poor prognosis and high incidence of diseases recurrence. How sphingolipid signaling regulates the function of immune cells and inflammation during tumor development remains poorly understood. Our results demonstrate that sphingolipid-induced inflammasome activation and IL-1β production promotes tumorigenesis and metastasis. Interestingly, our data indicate that SK-1/S1P signaling induces inflammasome activation and IL-1 production. We found that in MMTV-PyT transgenic mouse mammary gland tumor model, genetic loss of SphK1 significantly inhibited breast cancer progression and metastasis, accompanied by reduced levels of IL-1β at primary tumors and metastatic sites. Our results further show that SK1 and S1P modulate tumor microenvironments through induction of inflammasome activation and recruitment of myeloid cells. These findings indicate that the cross-talk between the SK1/S1P and inflammasome/IL-1 pathways promotes tumor growth and metastasis.
The efficacy of PD-L1 blockade on PD-L1 negative medulloblastoma is dependent on timing and the tumor microenvironment
Authors: Allen Frederick , Dorand Rodney Dixon , Rauhe Peter , Petrosiute Agne , Huang Alex Y. 
Published: January 2023

Abstract
PD-L1 blockade has shown great success in the rejection of specific PD-L1+ tumor-types within various tissues. Blocking PD-L1 interactions with PD-1 molecules expressed on effector T cells allow them to engage their targets unimpeded and enhances tumor rejections. However, most pediatric tumors and some adult tumors express low to no surface PD-L1. Interestingly, some reports have demonstrated the rejection of PD-L1 negative tumors after treatment with anti-PD-L1 antibodies (Abs). When we administered anti-PD-L1 Abs 7 days after injection of CRISPR-negative PD-L1 (crPD-L1neg) medulloblastoma (MM1) tumors, all tumors were rejected. However, treating with anti-PD-L1 Abs at the time of tumor inoculation (day 0), resulted in a greatly diminished response to further treatment and a loss of protection. In addition, analysis of day 7 treated tumors in comparison to isotype and day 0 treated tumors, revealed an ~4- and ~2-fold increase in PD-1+ CD8+ T cells by day 21, respectively. These data suggest that the efficacy of anti-PD-L1 Abs on PD-L1 negative tumors is dependent on the timing and the microenvironment in which the T cell priming occurs. Our lab is investigating this phenomenon by interrogating the interaction of DC-T cell priming in the tumor draining lymph nodes (TDLNs) during the early stages of tumor growth. These studies may lead to improved efficacy of immune checkpoint blockade in PD-L1 negative tumors.