bluuebunny/crossref_metadata_2025_split huggingface dataset:
Type I interferon and pro-inflammatory cytokine synthesis induced by Toll-like receptor signaling in dendritic cells is regulated by estrogen receptor alpha (57.7)
Authors: Kovats Susan , Bentley Caroline , Turner Sean , Roach Kimberly , Wilburn Stephanie , Khan Sohaib 
Published: January 2023

Abstract
Estrogen receptors (ER) regulate target gene expression by forming complexes with chromatin-modifying coregulators and transcription factors. Indeed, ER alter the activity of NF-κB and C/EBPβ, which are crucial regulators of cytokine gene expression. To test the hypothesis that ER alpha (ERα) signaling regulates pro-inflammatory cytokine and type I interferon production by CD11c+ dendritic cells (DC), we developed a novel line of mice, bearing CD11c-Cre and a conditional allele of ERα, in which ERα deficiency is restricted to CD11c+ cells. Isolated ERα+ or ERα-/- splenic DC were stimulated by Toll-like receptor (TLR) ligands in steroid-deficient medium with physiological levels (1 nM) of estradiol, followed by assessment of cytokine RNA and protein synthesis. ERα deficiency significantly reduced the synthesis of Ifna and Il6 RNA and protein by plasmacytoid DC triggered via TLR7 with influenza virus or via TLR9 with unmethylated CpG-rich DNA. In conventional DC stimulated via TLR9, ERα deficiency led to reduced levels of Il1a, Csf2, Ifnb, Nos2 and Ifng RNA and IL-1α and GM-CSF protein. Taken together, these data show that cell autonomous ERα signaling in DC promotes type I interferon and pro-inflammatory cytokine synthesis induced by pathogen-specific nucleic acids. Thus, estradiol-bound ERα may interact with transcription factors activated by TLR 7 and 9 signaling to increase transcription of cytokine genes, thereby regulating the ability of DC to promote pathogen immunity.
Listeria monocytogenes inhibits innate immunity by driving regulatory B10 cell expansion (58.10)
Authors: Weimer Eric , Horikawa Mayuka , Tedder Thomas 
Published: January 2023

Abstract
Regulatory B cells, including the CD1dhiCD5+ IL-10-competent regulatory B cell subset called B10 cells, significantly influence immune responses. In this study, B10 cell regulatory functions were examined during L. monocytogenes infection. Five days post-infection, B10 cells had expanded ≥2-fold in the spleen, lymph nodes, and blood of wild type mice. Remarkably, CD19-/- mice that lack B10 cells were more resistant to L. monocytogenes infection when compared with wild type mice. Furthermore, the adoptive transfer of wild type CD1dhiCD5+ B cells, but not CD1dloCD5- B cells, inhibited bacterial clearance in CD19-/- mice. To confirm the importance of endogenous B10 cell expansion in wild type mice, a monoclonal antibody that preferentially depletes B10 cells was given to mice before Listeria infection. B10 cell depletion lowered bacteria numbers in the spleen by two-logs when compared with control antibody-treated mice. Furthermore, monocytes from infected mice produced 2-3 fold more IFN-γ and TNF-α after B10 cell depletion. Taken together, these results argue that endogenous B10 cells negatively regulate monocyte activation and IFN-γ production, which are both critical for early Listeria clearance. As a consequence of lowered bacterial load, the proliferation of antigen-specific CD4+ T cells was reduced 5-fold in mice that were depleted of B10 cells. Thus, endogenous B10 cells negatively regulate innate immune responses during Listeria infection.
Immunization with heat-killed T. cruzi prior to T. cruzi infection causes increased cardiac inflammation and decreased parasitosis (58.11)
Authors: Bonney Kevin , Taylor Joann , Engman David 
Published: January 2023

Abstract
Chagas’ heart disease (CHD), caused by the protozoan parasite Trypanosoma cruzi, is a potentially fatal myocarditis often associated with cardiac-specific autoimmunity. Immunization with heat-killed T. cruzi (HKTC) induces polyantigenic autoimmunity similar to that observed during T. cruzi infection, as well as acute cardiac damage. However, HKTC-immunized mice do not develop myocarditis or the robust Th1/Th17-skewed immune response observed in T. cruzi-infected mice. We hypothesized that HKTC immunization inhibits inflammatory Th1 and Th17 responses and myocarditis by inducing a regulatory response (Treg). We infected mice that had been immunized with HKTC or PBS for 28 days with T. cruzi, and assessed the development of myocarditis and Th responses through 21 days post-infection. HKTC-immunized, infected mice developed more cardiac inflammation and lower cardiac parasitosis than controls, and a reduced Th1 response late in infection. This suggested that prior exposure to HKTC may actually suppress regulatory responses in infected mice. To assess the role of Tregs in these responses, we treated mice with neutralizing anti-CD25 antibody, and analyzed the development of myocarditis and Th responses following Treg depletion. Our findings suggest that autoimmunity may contribute to the pathogenesis of CHD, which has implications for the efficacy of antigen-based vaccines. We are continuing to investigate the mechanism(s) by which HKTC modulates the inflammatory response.
A possible TLR2-medited immunity to experimental cysticercosis caused by Taenia crassiceps (58.3)
Authors: Terrazas Luis I , Reyes Jose Luis , Gonzalez-Gonzalez Marisol I. , Satoskar Abhay R. 
Published: January 2023

Abstract
TLR2 is a key molecule required for innate immunity and is involved in the recognition of a wide range of pathogens from bacteria, fungi, parasites and viruses. Its role on immunity to cestode infections is poorly understood. Here the role of TLR2 was evaluated in a Taenia crassiceps infection model. Compared with wild-type mice, TLR2 knockout (KO) mice failed to produce significant levels of inflammatory cytokines in both sera and their spleens during the first two weeks of Taenia infection. TLR2 KO mice developed a Th2-dominant whereas wild-type mice developed a Th1-dominant immune response after Taenia infection. Associated with the insufficient production of early inflammatory cytokines and lack of Th1-dominant adaptive immunity, TLR2 KO mice developed significantly higher numbers of parasites whereas WT mice appeared to be resistant. TLR2 KO mice developed more amounts of alternatively activated macrophages. These results suggest that TLR2-dependent signaling pathway is not only required for inflammatory cytokine production in the early phase of host response to T. crassiceps infection but also that plays a critical role in the development of Th1-adaptive immunity, both of which may be essential for limiting infection and reducing pathology during experimental cysticercosis. Collectively, these studies indicate that TLR2 is involved in T. crassiceps recognition and subsequent innate immune activation.
Defective neutrophil function underlies the absence of T cell recruitment into challenge sites during elicitation of contact sensitivity in gld/perforin-/- mice (60.7)
Authors: Kish Danielle , Gorbachev Anton , Fairchild Robert 
Published: January 2023

Abstract
Contact hypersensitivity (CHS) is a CD8 T cell mediated response to hapten sensitization and challenge of the skin. Hapten-primed CD8 T cell infiltration into the skin challenge site is not observed until 12-16 h post-challenge and requires prior neutrophil infiltration and activation within the site. The neutrophil activities required to direct this T cell infiltration to mediate CHS responses are undefined. Although primed CD8 T cells do not express FasL or perforin, CHS responses to 2, 4-dinitrofluorobenzene (DNFB) are absent in gld/perforin-/- mice. ELISPOT analyses indicated equivalent priming of DNFB-specific CD8 cells in sensitized wild-type (WT) and gld/perforin-/- mice. Whereas DNFB-primed CD8 T cells from WT or gld/perforin-/-mice transferred CHS responses to naïve WT recipients, WT CD8 T cells did not transfer the response to gld/perforin-/- mice. Neutrophil infiltration into the challenge site of sensitized gld/perforin-/- and WT mice was equivalent at 6 h post-challenge but T cell infiltration was absent in the challenge site of gld/perforin-/- mice at 18 h. This T cell infiltration and the CHS response were restored by transferring WT neutrophils i.v. to sensitized gld/perforin-/- mice at challenge. Neutrophils from sensitized WT mice expressed high levels of FasL and perforin mRNA. These results indicate that neutrophil expression of FasL and perforin required to direct effector CD8 T cell recruitment into the skin challenge site to mediate CHS responses.
B cells have a dual effect on pulmonary fibrosis induced by bleomycin in a mouse model (61.11)
Authors: Hamaguchi Yasuhito , Tedder Thomas , Fujimoto Manabu 
Published: January 2023

Abstract
CD20 antibody immunotherapy effectively treats non-Hodgkin’s lymphoma and autoimmune diseases. However, the contributions of B cells to the pathophysiology of pulmonary fibrosis remains unknown. Therefore, the contributions of B cells to the initiation and progression of pulmonary fibrosis was quantified using the mouse model of bleomycin-induced fibrosis. B cell depletion before the induction of lung fibrosis substantially exacerbated disease symptoms. By contrast, B cell depletion during the inflammatory phase of pathology dramatically suppressed disease symptoms. Similarly, pulmonary fibrosis was also significantly worse in genetically B cell-deficient μMT mice when compared with wild type mice. The adoptive transfer of wild type B cells into μMT mice before disease initiation significantly reduced pulmonary pathology in μMT mice. Thus, B cells have important regulatory and pathogenic roles during the immunopathogenesis of lung fibrosis. These findings parallel published observations in the EAE model of multiple sclerosis and the NZBxW F1 mouse model of lupus, where a regulatory subpopulation of endogenous B cells (B10 cells) significantly reduces disease severity during early disease onset through the production of IL-10. Thereby, B cell depletion for the treatment of fibrosis may depend on the relative contributions and the timing of these opposing B cell activities during the course of disease.
Positive selection during affinity maturation relies on T cell derived BLyS (61.3)
Authors: Goenka Radhika , Mathews Andrew , O'Neill Patrick , Scholz Jean , Leonard Warren , Stohl William , Cancro Michael 
Published: January 2023

Abstract
Protective humoral immunity relies on high affinity B cell clones that are generated and selected during the germinal center (GC) reaction. To determine whether BLyS family member(s) play a role in this process, we assessed their distribution within the GC. We show that majority of the GC is devoid of BLyS despite the presence of ample BLyS in the adjacent follicular regions. The paucity of BLyS correlates with down-regulation of TACI receptor on GC B cells and likewise follicular B cells in TACI-deficient mice bind less BLyS. TACI down-regulation on follicular B cells is mediated by IL-21 in a surrogate thymus-dependent stimulation. Furthermore, some BLyS staining is detectable in the light zone associated by T Follicular Helper cells (TFH). The expression of BLyS by TFH is crucial for appropriate GC evolution, since efficient affinity maturation fails in mixed bone marrow chimeras where T cells are deficient in BLyS. We conclude that positive selection during affinity maturation relies on restricted sources of BLyS on GC TFH that provide survival signals to preserve high affinity clones.
Dendritic cell-B cell interactions in the marginal zone drive extrafollicular antibody responses. (61.4)
Authors: Chappell Craig , Draves Kevin , Giltiay Natalia , Clark Edward 
Published: January 2023

Abstract
Targeting Ag directly to dendritic cell (DC) subsets through the use of monoclonal antibodies (mAb) is increasingly being employed as a means to generate CD4 and CD8 T cell responses. However, the ability of individual DC subsets to raise primary Ab responses following Ag targeting is not well characterized. Using the hapten 4-hydroxy-3-nitrophenyl (NP) coupled to mAbs that recognize DC-specific DEC205 or DCIR2, we found that MZ-associated DCIR2+ DCs, but not DEC205+ DCs, were able to induce robust T cell- and CD40-dependent anti-NP Ab responses following injection of soluble Ag. Anti-NP Ab responses were restricted to the IgG1 sub-class but failed to either persist over time or undergo affinity maturation, despite the addition of TLR or RLR agonists. Using adoptive transfers with NP-specific B cells, we show that the unique ability of DCIR2+ DCs to induce Ab responses was associated with rapid, MHC class II-independent activation of Ag-specific B cells that occurred specifically upon Ag delivery to DCIR2. Importantly, we found that NP-specific B cells accumulated in MZ-associated bridging channels in close association with CD11c+ cells as early as 24hr following Ag delivery to DCIR2+ DCs. Together, these results reveal a previously unrecognized role for DC-B cell interactions in splenic bridging channels, and provide a novel mechanism for the initiation of T-dependent extrafollicular Ab responses.
TLR9 induces germinal center light zone expansion and augments B cell fate decisions (61.8)
Authors: Rookhuizen Derek , Sha William , DeFranco Anthony 
Published: January 2023

Abstract
Toll-like receptor 9 (TLR9) signaling regulates inflammatory processes in response to unmethylated CpG motifs that are enriched in viral, bacterial and protozoan DNA. While its roles in dendritic cell (DC) maturation, class switch recombination, and polyclonal B cell proliferation have been extensively studied, the importance of TLR9 in T-dependent germinal center (GC) B cell processes is unclear. To address this problem in vivo, we linked a biotinylated form of the model antigen NP-chicken gamma globulin (NP-CGG) with either biotin-CpG or biotin-nonCpG control (Ctrl) oligos using streptavidin and generated CpG- and Ctrl-conjugates, respectively. As early as 7dpi in the footpad of C57BL/6 mice, we observed TLR9-induced affinity maturation and a selective expansion of GC B cells in the light zone (LZ) where B cells receive survival signals from T follicular helper cells (Tfh) and selection for high affinity clones and distinct B cell fates occurs. We then looked for evidence of TLR9-enhanced selection and found increases in the GC to plasma cell transition as well as a robust increase in GC B cell CD38 expression that signifies memory B cell formation. We conclude that TLR9 selectively enhances light zone processes such as B cell fate decisions and enrichment for high affinity clones. The relationship between LZ expansion and fate decision is a future focus of this project.
Induction of antigen-specific B cell responses to pathogens — a balancing act! (61.9)
Authors: Baumgarth Nicole , Priest Stephen 
Published: January 2023

Abstract
Complex developmental and immune regulatory programs ensure that B cells respond to foreign but not to self-antigens. However, B cell responses can also be triggered non-specifically by mitogens, such as TLR-agonists, which seems counterintuitive and even dangerous. Furthermore, our studies showed a strong, albeit transient and highly specific increase of TLR3 and TLR7 in B cells that had accumulated in regional lymph nodes within 48h after infection with influenza virus, causing enhanced responsiveness of B cells to TLR7 agonists. This increase was induced by direct stimulation of B cells via the type I IFNR. While these observations provide a mechanism for the observed enhancing effects of type I IFN on antiviral B cell responses, they raise the question of how self-reactive responses are avoided, given that TLR7 overexpression has been directly linked to enhanced self-reactivity and autoimmune diseases. We hypothesize that signals must exist that counterbalance this increased sensitivity of B cells to TLR7 signals during influenza infection. Our data now suggest that type I IFN itself might provide such a counterbalance by suppressing B cell cell-cycle progression. Together our data indicate a dual role for type I IFN in differentially regulating specific and non-specific B cell responses after infection. They also raise questions about the role and function of the increased levels of type I IFN observed in patients with certain autoimmune diseases such as SLE.
Mitf family inhibition perturbs B cell homeostasis (62.14)
Authors: Lopez Ocasio Maria , Huan Chongmin , Roman Christopher 
Published: January 2023

Abstract
B cell activation is essential for recruitment of the appropriate antigen-specific B cells into an immune response and must be tightly controlled to avoid autoantibody production. The transcription factor Mitf, a member of the Mitf family of transcription factors that includes TFE3, TFEB and TFEC, is known to be important in restraining B cell activation by acting as a repressor of IRF4, itself needed for plasma cell development. However, the Mitf mutation caused osteopetrosis due to defective Mitf-dependent osteoclast development, and thus necessitated the evaluation of Mitf mutant B cells via adoptive transfer of Mitf-mutant stem cells into a normal host. In addition, the contribution of the other MiT family members that are also expressed in B cells was not evaluated. To address these issues, we have developed a single transgene model for B cell specific MiT family inactivation. The transgene encodes an artificial trans-dominant negative protein that forms inactive heterodimers with all four MiT family members. In preliminary data, we observed that mice that express this TDN protein in B cell lineage exhibit a number of B cell defects including splenomegaly, elevated numbers of spontaneous GCs and plasma cells, and perturbations to different B cell subsets. These data point to B cell subset specific dependency on the MiT family and possibly reveal the contribution of other MiT family members.
MicroRNA-mediated repression of XBP1: a novel mechanism for regulation of a UPR transcriptional activator (62.15)
Authors: Byrd Andrew , Brewer Joseph 
Published: January 2023

Abstract
The unfolded protein response (UPR), a multi-faceted signaling system emanating from the endoplasmic reticulum (ER) membrane, plays a critical role in the differentiation of B-lymphocytes into antibody-secreting plasma cells. Specifically, XBP1(S), a UPR transcriptional activator generated by IRE1-mediated splicing of Xbp1(u) mRNA, mediates expansion of the ER, up-regulates expression of many secretory pathway genes, and is required for normal antibody production. However, a full understanding of the molecular mechanisms regulating expression of Xbp1 is still lacking. Using bioinformatics analysis, we identified a microRNA (miR-30c-2*) predicted to target Xbp1 mRNA. Indeed, luciferase reporter assays demonstrated that miR-30c-2* targets a site in the 3’-untranslated region of Xbp1 mRNA in a sequence-specific manner. Over-expression of miR-30c-2* attenuated expression of both Xbp1 and XBP1(S) target genes, consistent with diminished expression of XBP1(S) protein. Furthermore, our studies revealed that expression of miR-30c-2* is up-regulated during UPR activation, concomitant with Xbp1, suggesting a feedback mechanism for XBP1(S) homeostasis. Finally, preliminary studies provided evidence linking expression of miR-30c-2* with specific UPR signaling events. These data provide the first link between microRNA and the UPR and, importantly, implicate miR-30c-2* in the regulation of Xbp1 and plasma cell differentiation.
Chromatin conformations and contacts that support Tcra/d locus rearrangement (62.2)
Authors: Shih Han-Yu , Olcott William , Krangel Michael 
Published: January 2023

Abstract
The Tcra/d locus rearranges in DN thymocytes to assemble Tcrd genes and in DP thymocytes to assemble Tcra genes. We used 3D-FISH to show that the 3’ portion of the locus is contracted in both DN and DP thymocytes, whereas the 5’ portion is contracted in DN but decontracts in DP thymocytes. We proposed that the fully contracted conformation in DN thymocytes allows dispersed Vαs to be used in a single round of Vδ-Dδ-Jδ rearrangement, whereas the 3’-contracted, 5’-decontracted conformation in DP thymocytes allows for multiple rounds of Vα-to-Jα rearrangement initiating with 3' Vαs. For high resolution analysis, we used the 3C method to detect molecular interactions between different sites in the locus. The Tcra enhancer (Eα) activates the T early α promoter (TEA) to target 5’Jαs for initial rearrangement. Eα also activates proximal Vαs over 500 kb. We detected molecular interactions between Eα and TEA, between Eα and proximal Vαs, and between different proximal Vαs, in DP but not DN thymocytes. All pairwise interactions depended on Eα. With TEA deleted, Eα also interacted with downstream Jαs. We propose that Eα nucleates a chromatin hub that supports transcription and ordered Vα-to-Jα recombination. However, deletion of Eα does not impact Tcra/d locus 3’end contraction as measured by 3D-FISH. Thus, overall locus conformation is independent of Eα, but this conformation may facilitate Eα interactions with distant sites.
Regulatory B10 cells activated in vivo transiently produce IL-10 before differentiating into antibody-secreting cells with a diverse BCR repertoire (62.4)
Authors: Bryant Jacquleyn , Candando Kathleen , Maseda Damian , Smith Susan , Weaver Casey , Dilillo David , Tedder Thomas 
Published: January 2023

Abstract
B cells with potent IL-10-dependent regulatory functions (B10 cells) expand in mice and humans during inflammation and autoimmunity. In this study, the fate of B10 cells following in vivo expansion was examined using two distinct il-10 reporter strains: Tiger mice that express cytoplasmic GFP and 10BiT mice that express cell surface Thy1.1. B10 cells from Tiger mice express cytoplasmic IL-10 and GFP with similar kinetics following stimulation in vitro and in vivo. By contrast, B10 cell Thy1.1 expression in 10BiT mice was delayed relative to IL-10 production and persisted even after B10 cells had lost the capacity to produce IL-10. Thy1.1 also served as a marker for B10 cells that expressed plasma cell-associated transcription factors and had the capacity to differentiate into CD138+B220LO antibody-secreting plasma cells in vivo and in vitro. Antibodies secreted by B10 cells included broadly reactive “natural antibodies” and autoantibodies, and were antigen-specific in immunized mice. At the molecular level, B10 cells predominantly expressed a germline-encoded IgM antibody repertoire with diverse VH and VL gene utilization. These results indicate that B10 cells can differentiate following IL-10 secretion to produce broadly-reactive germline-encoded antibodies that may function to rapidly clear antigens and further reduce inflammation and immunopathology.
Repertoire restriction of immunoglobulin DH gene segments impairs T cell regulation of a thymus-dependent immune response (62.7)
Authors: Lemke Hilmar , Trad Ahmad , Tanasa Radu , Zemlin Michael , Schroeder Harry 
Published: January 2023

Abstract
The significance of DH gene segments for the thymus-dependent (TD) immune response to the hapten 2-phenyloxazolone (phOx) was investigated in two mouse strains with a single DH gene segment that was derived from a modified DFL16.1 gene. In DD-DmuFS and in DD-iD mice, the central portion of the altered DH gene segment predominantly encodes for hydrophobic or charged amino acids, respectively. Compared with the response of BALB/c wild-type mice, the restriction of DH repertoire in both mutant strains caused drastic changes of the anti-phOx response. (i) The humoral anti-phOx antibody response was significantly reduced. (ii) Class switch recombination (CSR) was severely impaired. (iii) There was no restriction of VH/VL gene usage during CSR in the primary response and during further immune maturation. (iv) There was no selection of a dominant clonotype. (v) CSR did not select B cell clones with shorter and more uniform CDR-H3 lengths, as observed in BALB/c wild-type mice. These data confirm those obtained in wild-type mice and corroborate the view that CDR-H3-directed T cell action is important for clonal selection during CSR and immune maturation.