bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of a human toll-like receptor 3 antibody designed to block ligand binding and ligand mediated signaling (180.16)
Authors: Singh Sujay , Chitta Sriram , Lee Hyun-Ku , Singh Gita , Rosenberg Jonathan 
Published: January 2023

Abstract
Toll-like receptors (TLRs) play key roles during pathogen invasion to initiate innate immune responses. Toll-like receptor 3 (TLR3) recognizes double-stranded RNA (microbial and endogenous) and transmits signals to activate NF-kappa B. TLR3 is restricted to acidic pH+ intracellular compartments of innate immune cells (viz immature DC). Ligand binding and formation of multimeric signal complexes, to activate down-stream signaling, are facilitated by acidic pH in these compartments. Mutational and co-crystallization studies determined the interaction of TLR3 & ligand binding at the molecular level and also individual residues important in ligand recognition and signal transduction. Besides, neutralizing antibodies were utilized as tools for better understanding of ligand binding and TLR3 signaling. In the present study, we report results of a TLR3 antibody which blocks ligand (poly IC) binding and its' effect on functional activity. We tested multiple TLR3 antibodies, generated through use of synthetic peptides designed to include various regions of protein and also the residues playing important role in ligand binding. The binding and blocking (ligand) activities were analyzed by flow cytometry using TLR3 transfectant cells in presence/absence of poly IC. We also tested blocking activity in a functional assay by measuring secreted alkaline phosphatase (SEAP) in cultures of TLR3-NF-kB-SEAP co-transfectants stimulated wih poly IC in the presence of antibody.
Genetic screen reveals CYLD as a regulator of the balance between inflammation and cell death (180.18)
Authors: Schworer Stephen , Smirnova Irina , Poltorak Alexander 
Published: January 2023

Abstract
During the innate immune response to infection, a critical balance exists between the production pro-inflammatory cytokines and immune cell death. Cell death through RIP1-mediated regulated necrosis is emerging as an important mechanism through which cells respond to certain viral pathogens. To determine novel regulatory mechanisms of this signaling pathway, we studied cellular responses to TLR agonists in evolutionarily divergent wild-derived mice (MOLF/Ei) in a forward genetic screen of TLR-induced necrosis. In contrast to C57BL/6 macrophages, which are susceptible to TLR-induced necrosis, MOLF macrophages are resistant to death induced through this pathway. Using an N2 panel and forward genetic analysis, we found a locus on chromosome 8 that confers resistance to TLR-induced necrosis. Through gene expression analysis, allelic bias studies, and siRNA knockdown in peritoneal macrophages, we concluded that a genetic difference in CYLD confers the differential susceptibility to TLR-induced necrosis between B6 and MOLF macrophages. This difference was revealed through analysis of the regulation of CYLD mRNA splicing following TLR stimulation. The molecular defect that results in greater survival of MOLF cells appears to be mutually exclusive splicing of CYLD mRNA in activated or quiescent cells. Through our use of wild-derived mice in forward genetic analysis, we were able to uncover a key function of naturally occurring CYLD splice isoforms in a physiologic setting.
Regulation of TLR-triggered innate immune response by ubiquitin-specific protease 25 (180.8)
Authors: Zhong Bo , Liu Xikui , Wang Xiaohu , Liu Xindong , Chang SeonHee , Li Hongxiu , Darnay Bryant , Lin Xin , Sun Shaocong , Dong Chen 
Published: January 2023

Abstract
Protein ubiquitination plays a critical role in Toll-like receptor (TLR) signaling and innate immunity. Although several E3 ubiquitin ligases have been identified downstream of TLRs, the deubiquitination regulation in innate immunity is poorly understood. Here, we identified ubiquitin-specific protease 25 (USP25) as a novel negative regulator for TLR signaling. Deficiency of USP25 potentiated TLR2- and TLR4-induced activation of NF-kB and MAPKs and pro-inflammatory cytokine expression. Consistently, Usp25-/- mice exhibited increased susceptibility to LPS-induced septic shock than the control littermates. USP25 was found recruited to the TLR4 signaling complex and associated with TRAF3 and TRAF6 after LPS stimulation. Notably, USP25 specifically removed cIAP2-induced K48-linked ubiquitin conjugation of TRAF3 and loss of USP25 resulted in enhanced K48-linked ubiquitination and accelerated degradation of TRAF3 after TLR2/4 activation. Our findings thus identify USP25 as a novel, critical negative regulator in innate immunity via regulating TRAF3 degradation during TLR2/4 activation.
A genome guardian role for RAG-mediated restriction of repair pathway choice (42.10)
Authors: Coussens Marc , Wendland Rebecca , Deriano Ludovic , Arnal Suzzette , Roth David 
Published: January 2023

Abstract
The V(D)J recombinase, which includes the RAG 1/2 proteins, retains broken DNA intermediates in a post-cleavage complex, restricting repair to the canonical nonhomologous end joining (NHEJ) pathway. Previously, we described a C-terminal RAG2 truncation mutant that ablates repair pathway restriction, allowing RAG-generated DNA double strand breaks (DSBs) to access alternative NHEJ, an error-prone pathway characterized by junctional microhomologies and associated with oncogenic chromosome translocations. In “core” RAG2 knock in mice, which lack RAG2’s dispensable C-terminus, V(D)J junctions show characteristics of alternative NHEJ and thymocytes display genomic instability. RAG2 core/core p53-/- mice rapidly succumb to thymic lymphomas bearing complex chromosome translocations involving antigen receptor loci. Because the C-terminus of RAG2 contains multiple regulatory motifs, it remained unclear whether pathway choice restriction per se contributes to genomic stability. We now show that deleting or altering a C-terminal acidic “hinge” region destabilizes the post-cleavage complex, allows repair by alternative NHEJ, and promotes genomic instability. These data identify a novel regulatory region in RAG2 and show that the post-cleavage complex plays a genome guardian role by restricting repair pathway choice.
Interaction of the humoral immune system with peptides presented by class I major histocompatibility (MHC) complexes (42.4)
Authors: Held Gerhard , Luescher Immanuel , Neumann Frank , Sester Martina , Guillaume Philippe , Hoth Markus , Pfreundschuh Michael 
Published: January 2023

Abstract
Antibodies usually bind to unprocessed antigens, while cytotoxic T cells react with peptides derived from intracellular antigens when presented by class I major histocompatibility (MHC) complexes. We screened human sera for antibodies reacting specifically with the influenza matrix protein (IMP) derived peptide (58-66) displayed by HLA-A*0201 complexes by ELISA. Among blood donors, high-titered HLA-A*0201/IMP (58-66) complex-specific IgG antibodies were detected in HLA-A*0201- females with a history of pregnancies. Extended analyses of specificity indicated that these antibodies interacted peptide-specific with the MHC complex. No antibodies were detected in HLA-A*0201+ female or male blood donors. In another cohort of 218 females on delivery, only HLA-A*0201- mothers had HLA-A*0201/IMP (58-66) antibodies, which were also detected in the cord blood of the newborns, demonstrating that HLA-A*0201/ IMP58-66 antibodies are produced in HLA-A*0201- mothers and enter the fetal blood system. Refolding the peptide IMP (58-66) with all HLA-A, -B and -Cw alleles of the mothers and newborns revealed, that these antibodies are allo-reactive and are binding in some cases to the peptide displayed by a MHC allele of an offspring. Therefore allo-MHC/IMP (58-66) antibodies might provide immunity in HLA-disparate pregnancies. These antibody responses specific to a peptide displayed by a class I MHC complex opens a new dimension of interactions between the cellular and humoral immune system.
Retinoic acid regulates α-galactosylceramide-mediated B cell activation and differentiation in CD19hi and CD19lo B cell subsets (42.9)
Authors: Chen Qiuyan , Ross A. Catharine 
Published: January 2023

Abstract
B cells are professional antigen-presenting cells and effector cells for antibody production. Besides the B-cell receptor (BCR), B cells may possess BCR coreceptors and other antigen receptors, such as CD1d. Previously, all-trans retinoic acid (RA) has been shown to promote the differentiation of B cells, and increase CD1d expression and CD1d-mediated antibody production in vivo. The current study focused on the characterization of B cell differentiation regulated by RA and the CD1d ligand, α-galactosylceramide (αGalCer). Treatment of purified murine B cells with αGalCer and RA enriched a CD19hi B cell subpopulation with higher CD1d expression; these cells exhibited a more differentiated phenotype in terms of expression of costimulatory molecules CD40 and CD86; surface IgG1; the plasmacytic marker CD138; and Fas/PNA, markers of germinal center formation. RA and αGalCer also regulated the gene expression of transcription factor Pax-5 and IRF-4, as well as γ1-germline transcript, activation-induced cytidine deaminase (AID, Aicda), genes that control B cell proliferation and plasmacyte differentiation. Moreover, whereas αGalCer increased the expression of CD40, CD86 and Pax-5 that are critical factors for B cell activation, RA mainly enriched CD138+ and Fas+/PNA+ cells that represent the later stage of B cell differentiation. Our data demonstrate that αGalCer and RA are potent B cell regulators that play complementary roles to promote B cell differentiation.
Cellular basis for clearance of the protozoan parasite Babesia microti in immunocompromised hosts (43.13)
Authors: Vannier Edouard , Silver Zachary , Wilson Carrie , Su Jia-Shyuan , Chiam Jake , Laurie Sonia , Telford Sam , Gelfand Jeffrey , Krause Peter , Wortis Henry 
Published: January 2023

Abstract
Babesia microti is the primary etiologic agent of human babesiosis, an emerging infectious disease in the US. In healthy individuals, babesiosis typically causes a mild flu-like illness or is asymptomatic. In immunocompromised patients, particularly those with B cell lymphoma and treated with rituximab, babesiosis is severe, persistent, and sometimes fatal. The mechanisms by which the host controls this obligate parasite of erythrocytes are poorly understood. In C57Bl/6 mice, parasitemia is marginal and transient. Lack of mature B cells due to igh6 deficiency does not hinder resistance. In rag1-/- mice, however, parasitemia is intense and persists for at least three months. This pattern also is observed in athymic (nude) mice, in mice lacking TCRαβ cells and in MHCii-/- mice. Surprisingly, parasitemia is intense but transient in cd4-/- mice. In the spleens of these mice, CD8+ T cells and CD4-CD8- T cells greatly expand during the course of infection. Parasitemia resolves in cd4-/- cd8-/- mice, but persists in cd4-/- igh6-/- mice. Likewise, parasitemia persists in cd4-/- mice depleted of B cells by repeated administration of anti-CD20. Resolution of parasitemia in cd4-/- mice is concomitant with the rise in circulating Babesia specific IgG, but does not require Fc receptors as demonstrated in cd4-/- fcegr1-/- mice. Our studies establish that, in the absence of CD4, B cells are critical for resolution of babesiosis. The role of complement and cytokines will be discussed.
Phagocytosis, Interferon-γ, IL-21, and CD4+ MHC class II-restricted T cells in resistance to Babesia microti infection (43.14)
Authors: Laurie Sonia , Vannier Edouard , Wortis Henry 
Published: January 2023

Abstract
Babesiosis is an emerging infectious disease caused by the hematoprotozoan parasite Babesia microti. The mechanisms of resistance to B. microti are not fully understood. The laboratory has developed a murine model of babesiosis with many of the features of the human disease that is used to examine the genetic determinants of resistance. The goal of the present study was to identify cellular processes that convey resistance to this parasitic infection. We established that the depletion of macrophages by chronic administration of clodronate liposomes resulted in early (0 to 30 days post-infection) hyperacute phase parasitemia (quantified as percent parasitized erythrocytes) but did not affect late phase (days 35-50) clearance of B. microti. In contrast, the absence of MHC-ii or the αβ T cell receptor prevents both early and late resistance. We find that early resistance requires the production of the cytokine IL-21. We also observed that the dual loss of CD4 and IL-21 results in the complete loss of resistance. We therefore hypothesize that IL-21 activates CD4+ T lymphocytes to synthesize IFN- γ that, in turn, activates macrophages to phagocytose and destroy B. microti infected red blood cells or B. microti itself. A model of resistance that incorporates these observations will be presented.
MyD88 acts directly on CD4+ T cells to promote resolution of Chlamydia muridarum genital tract infection (43.18)
Authors: Frazer Lauren , Zurenski Matthew , Mintus Margaret , Darville Toni 
Published: January 2023

Abstract
MyD88-dependent signaling is required for resolution of Chlamydia muridarum genital tract infection. We hypothesized that MyD88 was required for development of a robust chlamydiacidal CD4+ T cell response. Examination of chlamydia-specific cytokine production by CD4+ T cells in the genital tract revealed a 2-fold decrease in the frequency of CD4+ T cells producing IFNγ in the oviducts of MyD88-/- mice, but this difference was not statistically significant and was accompanied by an increased frequency of TNFα producing CD4+ T cells. In addition, the absolute number of CD4+ T cells in the oviducts, uterine horns, and lymph nodes did not differ between the strains. These data indicate that impaired trafficking of T cells to the genital tract is not responsible for the deficits in resolution of infection and that the defective chlamydiacidal capacity of MyD88-/- T cells may be IFNγ-independent. To determine if MyD88 plays a direct role in promoting T cell chlamydiacidal capacity, MyD88-/- or WT CD4+ T cells were transferred into Rag1-/- mice. Infection was significantly increased (p&lt;0.01, two-way RM ANOVA) and prolonged (p&lt;0.03 via log-rank test) when T cells lacked MyD88, with a median time to clearance of 23 days for mice receiving WT CD4+ T cells and 47 days for mice receiving MyD88-/- CD4+ T cells. MyD88 directly promotes the chlamydiacidal function of CD4+ T cells in vivo, but the precise requirement for this molecule remains to be determined.
IL-25 mediates the induction of IL-9-producing T cell responses against T. spiralis infection (43.20)
Authors: Angkasekwinai Pornpimon , Srimanote Potjanee , Wang Yui-Hsi , Sakolvaree Yuwaporn , Pattanapanyasat Kovit , Chaicumpa Wanpen , Chaiyaroj Sansanee , Dong Chen 
Published: January 2023

Abstract
IL-9-producing T cells were shown to be important in immunity against helminth infection, however, the occurrence and regulation of this distinct cell subset during T. spiralis infection remain elusive. Here, we showed that the occurrence of both IL-9-producing T cells (Th9 cells) and Th2 cells increased significantly at early stage of infection. While the frequency of induced Th2 cells within mesenteric lymph node sustained, Th9 cells declined sharply after 14 days of infection. Notably, we observed that the transient expression of IL-25 transcript preceded those of IL-9 and IL-4 genes in the intestine during T. spiralis infection. Administration of anti-IL-25-neutralizing antibody into T. spiralis-infected mice resulted in the reduction of antigen specific Th9 cell development, which was correlated with the increased worm burden. In addition, the expression of intestinal IL-9-regulated genes, including mast cell and paneth cell-specific genes such as mast cell protease 1, and angiogenin 4 (Ang4), cryptdins, and phospholipase A2 were markedly reduced in the intestine of T. spiralis-infected mice after IL-25 blockade, but strongly up-regulated after IL-25 treatments. Our study reveals a temporal expression pattern of Th9 development during helminth infection and suggests that IL-25 may play key roles in regulating the induction of protective IL-9 immune response against parasitic infection.
Experimental tuberculosis in the humanized mouse (43.28)
Authors: Endsley Janice , Calderon Veronica , Valbuena Gustavo , Goez-Rivillas Yenny , Judy Barbara , Johnston Rebecca , Estes Don , Cirillo Jeffrey 
Published: January 2023

Abstract
Currently there is no animal model of HIV/Mtb co-infection, limiting our understanding of how HIV-induced defects in immune function promote the dramatic susceptibility to Mtb. The humanized mouse is contributing to discoveries relevant to HIV/AIDS, but the model has not been further developed for opportunistic infection. The goal of this project was to develop the humanized mouse as a small animal model of Mtb infection to determine the potential use for HIV/Mtb co-infection research. NOD-SCID/γcnull mice were engrafted with human fetal liver and thymus tissue, and injected intravenously with CD34+ fetal liver cells. At 12 weeks following engraftment in this model we observe that on average, 40% of the total leukocytes in mouse peripheral blood are human CD45+ cells. These human leukocytes include human T cells (CD4 and CD8), as well as NK cells, and antigen presenting cells (macrophages, DC). Importantly, the circulating human T cells and NK cells respond to specific antigen and/or positive stimuli as measured by proliferation and expression of effector molecules (e.g. IFN-γ, granulysin). Animals infected intranasally with Mtb have progressive bacterial infection in the lung, dissemination of bacteria to spleen and liver, and formation of organized granulomatous lesions at sites of infection. The results demonstrate the utility of the humanized mouse as a model of experimental TB and suggest promise as a small animal model of HIV/Mtb co-infection.
Abnormal distribution of peripheral B lymphocyte subpopulations in chronic human Trypanosoma cruzi infection (43.7)
Authors: Postan Miriam , Fernandez Esteban , Gonzalez Mariela , Hernandez Vasquez Yolanda , Sirena Natalia , Moran Maria , Ledesma Oscar , Olivera Gabriela 
Published: January 2023

Abstract
In previous studies we have shown that human chronic T. cruzi infection is associated with abnormalities of CD8+ and CD4+ T cell compartments, probably as a consequence of chronic antigenic stimulation by persisting parasites. In this study, we measured the levels of circulating B cell subsets in 25 patients chronically infected with T. cruzi and 19 non-infected controls (mean age±SD=41.0±12.2 and 34.9±10.6 y respectively). The results showed that T. cruzi-infected patients had higher percentages of CD19+CD27-IgD+ (naïve; mean%±SD=54.1±16.1) and lower percentages of CD19+CD27+ (Ag-experienced; mean%±SD=35.8±16.5) B lymphocytes compared to controls (mean%±SD=33.8±15.8 and 55.7±18.0, respectively, p&lt;0.05), with similar levels of CD69 or CD86 activation markers. The observed memory B cell reduction comprised switched (IgD-) and no-switched (IgD+) subsets (mean%±SD=17.9±11.2 and 17.9±12.6, respectively) in relation to controls (mean%±SD=30.9±17.8 and 24.8±16.4, respectively; p&lt;0.05). The proportion of CD19+CD27+CD138+ plasma cells in patients was lower than in the controls (mean%±SD=5.0±3.6 and 26.4±27.1 respectively; p&lt;0.05), with no differences in CD19+CD10+ cell levels (immature; mean%±SD=5.6±4.7 and 4.3±3.3, respectively). The accumulation of naïve and loss of memory B cell and plasma cell subsets in chronic Chagas disease patients indicate that T. cruzi infection affects the phenotypic profile of the peripheral blood B cell-compartment. Support: FONCyT PICT 2007 N°1732
TNF-alpha modulates alveolar bone repair under homeostatic conditions in mice (44.1)
Authors: Garlet Gustavo , Vieira Andreia , Repeke Carlos Eduardo , Francisconi Carolina , Silveira Elcia , Assis Gerson , Taga Rumio , Campanelli Ana Paula , Trombone Ana Paula 
Published: January 2023

Abstract
Cytokines have been implicated in the pathogenesis of bone diseases, but its role in bone repair process remains unknown. Our objective was to characterize the role of TNF-alpha in alveolar bone healing after tooth extraction in mice. Following the extraction of the right upper incisor of C57Bl/6(WT) and TNFp55KO strains, the maxilla containing the remaining alveolus was collected for histomorphometric and molecular (RealTimePCR) analysis. In WT mice the initial formation of clot was followed by the transient inflammatory infiltrate and a granulation tissue, gradually substituted by bone. In WT mice TNF-a mRNA was detected with an initial peak at 7 days, followed by a decreasing expression over time and a second peak at 28 days. Bone markers expression presented an initial high expression of COL-I, followed by CBFA-1 and ALP and subsequently by OCN and PHEX. TNFp55KO strain presented a delayed angiogenesis and osteogenesis processes, increased inflammatory reaction, despite of a decrease in CXCL1, CCL-2 and CCL3 levels; and increased COL-I mRNA levels and decreased CBFA-1, ALP, OCN and PHEX expression. The results presented here demonstrate that the absence of TNF-alpha interferes in alveolar bone repair through mechanisms that involve the modulation of inflammatory cell migration and osteogenic markers expression during the course of alveolar bone repair.
Different GATA factors dictate CCR3 transcription in a cell type-specific manner of allergic inflammatory cells (44.10)
Authors: Chung Il Yup , Kong Su-Kang , Kim Byung Soo , Uhm Tae Gi , Hwang Sae Mi , Kang Jin Hyun 
Published: January 2023

Abstract
CCR3 is expressed in prominent allergic inflammatory cells, including eosinophils, mast cells, and Th2 cells, which preferentially express GATA-1, GATA-2, and GATA-3, respectively. We have previously demonstrated GATA-1-mediated CCR3 transcription with functional mapping of a GATA element in the regulatory region of CCR3 gene. Herein, we investigated whether GATA factors other than GATA-1 play a major role in CCR3 transcription in these cell types. A CCR3 reporter plasmid, but not a mutant CCR3 reporter lacking the functional GATA element, was activated in all three cell types, EoL-1 eosinophilic cells, HMC-1 master cells, and Jurkat T cells, suggesting a critical involvement of the GATA element regardless of cell types expressing different GATA factors. Knockdown assay showed that siRNAs directed to GATA-1 and GATA-2 significantly reduced CCR3 transactivation with an additive effect in EoL-1 and HMC-1 cells, while GATA-3 siRNA exclusively abrogated CCR3 transcription in Jurkat cells. In parallel, EMSA analysis showed that the functional GATA element preferentially bound GATA-1, GATA-2, and GATA-3 with nuclear extracts from EoL-1, HMC-1, and Jurkat T cells, respectively. These results highlight that different GATA factors are engaged in CCR3 transcription in a cell type-specific fashion, depending on the major allergic inflammatory cells.