bluuebunny/crossref_metadata_2025_split huggingface dataset:
NK cell Activation during Acute Hepatitis C Virus Infection (45.18)
Authors: Pelletier Sandy , Bédard Nathalie , Drouin Christian , Khakoo Salim , Bruneau Julie , Shoukry Naglaa H. 
Published: January 2023

Abstract
Genetic studies have implicated the inhibitory natural killer (NK) cell receptor KIR2DL3 and its human leukocyte antigen C group 1 (HLA-C1) ligand in resolution of hepatitis C virus (HCV) infection but a functional correlation was not established. To examine the role of NK cells during acute HCV, we have analyzed longitudinally the phenotype and function of NK cells from a cohort of patients following HCV exposure. Three groups with different infectious outcome were identified: spontaneous resolvers (SR), chronic evolution (C) and exposed un-infected (EU) (n=10 in each group). We have observed increased NK cell cytotoxicity (%CD107a+) in all groups suggesting NK cell activation following exposure but no correlation was established with infectious outcome. Nevertheless, we observed decreased expression of KIR2DL1, associated with highest NK cell inhibition, in SR. Furthermore, the highest IFN-γ production was observed in KIR2DL3+ NK cells, the least inhibited population, in all groups. Our results suggest that NK cell direct cytotoxicity might not be implicated in HCV clearance but that less NK cell inhibition is more frequent in SR patients. These results confirm the important role of host genetic background in NK cell function and provides the first demonstration of such a functional correlation in an in vivo infection setting.
Research support: The Dana Foundation, CIHR, FRSQ, NCRTP-HepC
Mucosal Epithelial Cells Provide the Critical Link for Dendritic Cell-mediated Amplification of HIV (45.19)
Authors: Fontenot Danielle R , He Hong H , Hanabuchi Shino , Nehete Pramod N , Ma Zhong-min , Courtney Amy N , Miller Christopher J , Sun Shao-Cong , Liu Yong-Jun , Sastry K. Jagannadha 
Published: January 2023

Abstract
An estimated 30-40% of all new HIV-1 infections occur in women through the vaginal mucosa even though it carries a lower transmission probability per exposure rate (1/200 - 1/2,000) than both rectal and mother to child transmission (1/10 - 1/300). Paradoxically, the mucosal epithelial cells express low to negligible levels of the HIV receptors and the mucosal tissue microenvironment is laden with numerous antiviral factors. We obtained in vitro and in vivo evidence of HIV manipulating the mucosal microenvironment to sustain and increase infection by inducing genital mucosal epithelial cells to produce thymic stromal lymphopoietin (TSLP), a cytokine known to activate DC to induce robust CD4+ T cell homeostatic expansion. We provide molecular evidence for the involvement of NFκB signaling pathway in HIV-induced TSLP expression. In rhesus macaques we observed dramatic increases in TSLP expression concurrent with increases in DC and CD4+ T cell numbers, and viral replication in the vaginal tissues within the first two weeks after vaginal SIV exposure. Our studies demonstrate that HIV-mediated TSLP production by mucosal epithelial cells is a critical trigger for DC-mediated amplification of HIV-infection in activated CD4+ T cells. The cross talk between mucosal epithelial cells and DC, mediated by HIV induced TSLP, is a novel mechanism important for AIDS pathology that should be explored for therapeutic potential.
Rat coronavirus infection of alveolar type I cells causes neutrophil recruitment followed by resolution of infection (45.28)
Authors: Miura Tanya A. , Funk Joel , Holmes Kathryn V. , Mason Robert J. 
Published: January 2023

Abstract
Viral infections in the lung are an important cause of morbidity and mortality in humans worldwide. In order to design strategies for vaccination and therapy, we need to understand the molecular mechanisms that initiate and regulate effective antiviral immune responses in the lung. This requires animal models in which in vitro mechanistic studies can be correlated with infections in vivo. We study rat coronavirus (RCoV) infection in rats and cultures of primary differentiated rat alveolar epithelial cells as a model for the early events in respiratory coronavirus pathogenesis. Intratracheal inoculation of adult rats with RCoV resulted in infection of the lung, primarily in alveolar type I cells. Infection caused transient weight loss and focal lesions and recruitment of neutrophils in the lung, followed by clearance of virus and resolution of inflammation. Thus, adult rats mounted an effective innate immune response to RCoV infection in the lung. In agreement, in primary cultures of differentiated rat alvoelar type I cells, RCoV replicated and induced expression of neutrophil chemotactic CXC chemokines. This in vitro model will elucidate the molecular interactions between RCoV and alveolar epithelial cells that initiate and regulate the innate antiviral immune response in the lung.
This work was supported by NIH grants AI-059576 and HL-029891, and NCRR/NIH grant P20 RR015587.
Epitope-Specific Regulatory T cells Differentially Modulate the CD8 T Cell Response to Respiratory Syncytial Virus in Mice (45.29)
Authors: LIU JIE , RUCKWARDT TRACY , CHEN MAN , JOHNSON TERESA , GRAHAM BARNEY 
Published: January 2023

Abstract
RSV infection is the leading cause of lower respiratory disease in infants and young children, accounting for &gt;120,000 hospitalizations each year in the US alone. Although CD8 T cell effector function is key to virus clearance, CD4 T cells coordinate the immune response and can lead to immunopathology. Therefore, they play a central role in the immunity and immunopathogenesis of RSV infection.
To facilitate in depth evaluation of RSV-induced CD4 T cell responses we identified two new I-Ab- restricted dominant CD4 T cell epitopes, M213-223 and M227-37, in RSV M and M2 that also contain well characterized CD8 T cell epitopes. CD4 T cells from lung and spleen of RSV-infected CB6F1 mice produce different patterns of IL-2, IFN-γ and other cytokines after peptide stimulation. Novel tetrameric peptide-I-Ab complexes identified 0.5% and 1.6% RSV M- and M2-specific CD4 T cells in lungs of the infected mice. Peptide-stimulated CD4 T cells produced different patterns of regulation on CD8 T cell responses to RSV M and M2 epitopes in vitro. The regulatory function of the CD4 T cell correlated with the level of FoxP3 expression in epitope-specific CD4 T cells Our study demonstrates that the biophysical properties of the epitope may dictate the functional properties of the CD4 T cell response. Understanding how epitope structure influences T cell function will provide new insight into viral pathogenesis and may improve vaccine design.
Liver cCD8a+DC from Mice Immunized with Gamma-irradiated Plasmodium berghei Sporozoites Mediate the Induction of Intrahepatic Effector CD8+ T cells against Liver-Stage Malaria (45.30)
Authors: Krzych Urszula , Jobe Ousman , Schwenk Robert 
Published: January 2023

Abstract
Immunization with radiation (γ)-attenuated Plasmodia sporozoites (γ-spz) confers sterile and long-lasting immunity against malaria liver-stage infection. In the P. berghei γ-spz model, protection is linked to liver CD8+ T cells that express an effector/memory (TEM) phenotype, (CD44hiCD45RBloCD62Llo ), and produce IFN-γ. However, neither the antigen presenting cells (APC) that activate these CD8+ TEM cells nor the site of their induction have been fully investigated. Because conventional (c)CD8α+ DC (a subset of CD11c+ DC) are considered the major inducers of CD8+ T cells, in this study we focused primarily on cCD8α+ DC from livers of mice immunized with Pb γ-spz and asked whether the cCD8α+ DC might be involved in the activation of CD8+ TEM cells. We demonstrate that multiple exposures of mice to Pb γ-spz lead to a progressive and nearly concurrent accumulation in the liver but not the spleen of both the CD11c+NK1.1- DC and CD8+ TEM cells. Upon adoptive transfer, liver CD11c+NK1.1- DC from Pb γ-spz-immunized mice induced protective immunity against sporozoite challenge. Moreover, in an in vitro system, liver cCD8α+ DC induced naïve CD8+ T cells to express the CD8+ TEM phenotype and to secrete IFN-γ. The in vitro induction of functional CD8+ TEM cells by cCD8α+ DC was inhibited by anti-MHC class I and anti-IL-12 mAbs. These data suggest that liver cCD8α+ DC present liver-stage antigens to activate CD8+ TEM cells, the pre-eminent effectors against pre-erythrocytic malaria. These results provide important implications towards a design of anti-malaria vaccines. Supported by a grant from NIH and USAMRMC.
RICK/RIP2 Promotes Inflammation and Lethality after Gram-Negative Bacterial Infection in Mice Stimulated with Lipopolysaccharide (45.4)
Authors: Park Jong-Hwan , Kim Yun-Gi , Nunez Gabriel 
Published: January 2023

Abstract
RICK, a serine-threonine kinase, functions downstream of the pattern-recognition receptors Nod1 and Nod2 to mediate NF-kB and MAPK activation in response to specific microbial stimuli. However, the function of RICK in the recognition and host defense of Gram-negative bacteria remains poorly understood. We report here that infection of wild-type and RICK-deficient macrophages with Pseudomonas aeruginosa and Escherichia coli, elicited comparable activation of NF-kB and MAPKs as well as secretion of pro-inflammatory cytokines. However, production of IL-6 and IL-1b induced by these Gram-negative bacteria was impaired in RICK-deficient macrophages when the cells were previously stimulated with LPS or E. coli. The diminished pro-inflammatory response of RICK-deficient macrophages to bacteria was associated with reduced activation of NF-kB and MAPKs. Importantly, mutant mice deficient in RICK were less susceptible than wild-type mice to P. aeruginosa infection when the animals were previously stimulated with LPS. The reduced lethality of RICK-deficient mice infected with P. aeruginosa was independent of pathogen clearance, but was associated with diminished production of pro-inflammatory molecules in vivo. These results demonstrate that RICK contributes to the induction of pro-inflammatory responses and susceptibility to Gram-negative bacteria after exposure to LPS, a condition that is associated with reduced TLR signaling.
Poly-gamma-D-glutamic acid and protective antigen conjugate vaccines induce functional antibodies against the protective antigen and capsule of Bacillus anthracis in guinea pigs and rabbits (45.8)
Authors: Rhie Gi-eun , Lee Deog-Yong , Ha Hyun-Joon , Park Jungchan , Chun Jeong-Hoon , Oh Hee-Bok , Yoo Cheon-Kwon 
Published: January 2023

Abstract
Anthrax is a lethal infectious disease caused by spore-forming Bacillus anthracis. The two major virulence factors of B. anthracis are exotoxin and the poly-gamma-D-glutamic acid (PGA) capsule. The three components of exotoxin, protective antigen (PA), lethal factor and edema factor act in binary combination, which results in massive edema and organ failure in the progress of anthrax disease. The antiphagocytic PGA capsule disguises the bacilli from immune surveillance and allows unimpeded growth of bacilli in the host. Because PA can elicit a protective immune response, it has been a target of anthrax vaccine. In addition to PA, efforts have been made to include PGA as a component of anthrax vaccine. In this study, we report that PA-PGA conjugates induce expression of anti-PA, anti-PGA and toxin neutralizing antibodies in guinea pigs and completely protect guinea pigs against a 50xLD50 challenge with fully virulent B. anthracis spores. Polyclonal rabbit antisera produced against either PA or ovalbumin conjugated to a PGA 15mer offers passive protection to guinea pigs against B. anthracis infection, indicating that anti-PGA antibodies play a protective role.
This work was supported by Korea National Institute of Health Grants (H. H and G. R.).
Differential requirements of MHC and of DCs for endogenous proliferation of different T cell subsets in vivo (46.16)
Authors: Min Booki , Do Jeong-su 
Published: January 2023

Abstract
T cells transferred into severe lymphopenic hosts undergo rapid proliferative responses that are distinct from conventional homeostatic proliferation, known as 'endogenous proliferation'. Unlike homeostatic proliferation, cytokines such as IL-7 is dispensable, yet TCR interaction with peptide:MHC complexes is believed to be essential for this process to occur. However, cell types inducing the proliferation have not been defined. In this study, we provide evidence that CD11c+ conventional DCs play pivotal roles in inducing endogenous proliferation of both naive and memory phenotype CD4 T cells via TCR-MHC II interaction. T cells transferred into MHC II-/- TCRβ-/- or CD11c+ DC-deleted TCRβ-/- recipients failed to undergo endogenous proliferation. By contrast, CD8 T cell endogenous proliferation was independent of MHC I or CD11c+ DCs. Interestingly, depleting both B cells and DCs was able to abrogate the proliferation of naive CD8 T cells in TCRβ-/- environments. However, memory phenotype CD8 T cell proliferation was not abrogated by the absence of both B cells and DCs. Taken together, these results strongly suggest that depending on the T cell lineages as well as the differentiation status different mechanisms operate during endogenous proliferation, revealing unexpected in vivo complexity of T cell proliferation under lymphopenic conditions.
Route of infection determines T helper-1 versus T helper-17 subset differentiation (46.9)
Authors: Linehan Jonathan , Dileepan T. , Cleary Pat , Jenkins Marc 
Published: January 2023

Abstract
How environmental cues distinctly shape CD4+ T cell differentiation in response to specific bacterial infections remains largely unknown. Here we tested whether the route of infection determined which cytokines were produced by specific memory CD4+ T cells. Listeria monocytogenes and Streptococcus pyogenes were engineered to express the 2W1S antigenic peptide (LM-2W1S and SP-2W1S) and used to infect C57BL/6 mice. Endogenous 2W1S-specific CD4+ T cells were tracked using a 2W1S:I-Ab tetramer and magnetic bead enrichment. Infection with either LM-2W1S or SP-2W1S via the intranasal route resulted in splenic 2W1S:I-Ab-specific CD4+ memory cells that produced interleukin-17A (IL-17A) but not interferon-γ (IFN-γ) upon in vivo challenge, whereas infection with LM-2W1S or SP-2W1S via the intravenous route resulted in splenic 2W1S:I-Ab-specific memory cells that produced IFN-γ, but not IL-17A. These results suggest that the lymphoid environment of primary antigen encounter is an important factor in determining the type of CD4+ T cell memory generated and indicate that the route of immunization should be a major consideration when designing vaccines to improve cell-mediated immunity.
This work was funded by the NIH.
c-Maf determines IL-10 regulation during Th17 polarization (47.22)
Authors: Xu Jiangnan , Yang Yu , Lal Girdhari , Ochando Jordi C. , Bromberg Jonathan S. , Ding Yaozhong 
Published: January 2023

Abstract
IL-10 production by Th17 cells is critical for limiting autoimmunity and inflammatory responses. Gene array analysis on Stat6 and T-bet double deficient Th17 cells identified the Th2 transcription factor c-Maf to be synergistically up-regulated by IL-6 plus TGFβ, and associated with Th17 IL-10 production. Both c-Maf and IL-10 induction during Th17 polarization depended on Stat3, but not Stat6 or Stat1, and mechanistically differed from IL-10 regulation by Th2 or IL-27 signals. TGFβ was also synergistic with IL-27 to induce c-Maf, and induced Stat1 independent IL-10 expression in contrast to IL-27 alone. Retroviral transduction of c-Maf induced IL-4/Stat6 independent IL-10 expression, and c-Maf directly transactivated IL-10 gene expression through binding to a MARE motif in the IL-10 promoter. Together, these data reveal a novel role for c-Maf in regulating T effector development, and suggest that TGFβ may antagonize Th17 immunity by IL-10 production through c-Maf induction.
iNKT Cell-development is Orchestrated by Different Branches of TGF-beta Signaling (47.24)
Authors: MARIE Julien C , Doisne Jean-Marc , Garcia Céline , Bartholin Laurent , Losson Régine , Benlagha Kamel 
Published: January 2023

Abstract
iNKT cells constitute a distinct subset of T lymphocytes exhibiting important immune-regulatory functions. Although different steps of their differentiation have been well characterized, the factors controlling their development remain poorly documented. Here, we show that TGF-β controls the differentiation program of iNKT cells. We demonstrate that TGF-β signaling finely and specifically orchestrates several steps of iNKT cell development. In vivo this multifaceted role of TGF-β involves the concerted action of different pathways of TGF-β signaling. Whereas the Tif-1γ branch controls lineage expansion, the Smad4 branch maintains the maturation stage that is initially repressed by a Tif-1γ/Smad4-independent branch. Thus, these three different branches of TGF-β signaling function in concert as complementary effectors allowing TGF-β to finely tune the iNKT cell-differentiation program.
Isolated CD39 Expression On CD4+ T Cells Denotes Both Regulatory and Memory Populations (47.26)
Authors: Zhou Qiang , Putheti Prabhakar , Wu Yan , Kassam Nasim , Enjyoji Keiichii , Robson Simon C. , Strom Terry B. , Gao Wenda 
Published: January 2023

Abstract
Foxp3+ regulatory T cells (Tregs) express both ectoenzymes CD39 and CD73, which in tandem hydrolyze pericellular ATP into adenosine, an immunoinhibitory molecule that contributes to Treg suppressive function. Using Foxp3GFP knockin mice, we noted that the mouse CD4+CD39+ T cell pool contains two roughly equal size Foxp3+ and Foxp3- populations. While Foxp3+CD39+ cells are CD73bright and are the bone fide Tregs, Foxp3-CD39+ cells are CD44+CD62L-CD25-CD73dim/-, exhibiting memory cell phenotype. Compared with Foxp3-CD39- naïve T cells, Foxp3-CD39+ cells freshly isolated from non-immunized mice express strikingly higher levels of mRNA for T helper lineage specific cytokines IFN-γ (Th1), IL-4/IL-10 (Th2), IL-17A/F (Th17), as well as pro-inflammatory cytokines IL-1, IL-6, TNF-α, and MCP-1. Upon stimulation, Foxp3-CD39+ but not Foxp3-CD39- cells rapidly secrete these cytokines. Moreover, the presence of Foxp3-CD39+ cells inhibits TGF-β-induced conversion of Foxp3-CD39- cells into iTregs. Thus, CD39 denotes both Treg and pre-existing memory T cells of Th1-, Th2-, and Th17-types.
TRAF6 is an Intrinsic Negative Regulator of Th17 Differentiation (47.32)
Authors: Cejas Pedro Joel , Walsh Matthew C , Pearce Erika L , Harms Gretchen , Choi Yongwon 
Published: January 2023

Abstract
The newly defined Th17 cell subset of CD4+ T cells is characterized by their ability to secrete IL-17A, IL-17F and IL-22, as well as by the expression of the transcription factor RORγt. Differentiation into the Th17 phenotype requires TGF-β1 and IL-6 both in vivo and in vitro, and is negatively regulated by non-Th17 cytokines such as IL-4, IFN-γ, IL-27 and IL-2. Interestingly, the negative effect of IL-2 is suppressed by IL-1.
TRAF6 is an intracellular adaptor protein that mediates signalling from the IL-1 receptor, so we reasoned that TRAF6-deficient CD4+ T cells would show impaired Th17 differentiation. To our surprise, TRAF6-deficient CD4+ T cells show preferential differentiation into the Th17 phenotype. In contrast, we have previously shown that in presence of the corresponding stimuli, in vitro differentiation into the Th1 or Th2 subsets is not affected in TRAF6-deficient CD4+ T cells. The observed Th17 bias is also reflected in vivo, as mice with a T cell-specific TRAF6 gene deletion (TRAF6-ΔT) show increased IL-17-producing cells. We have analyzed the effects of increased IL-17 levels in TRAF6-ΔT mice as well as the molecular reasons that explain the negative effect of TRAF6 in Th17 differentiation.
Neither Smad2 or Smad3 is essential for TGF-β to induce Foxp3+ Tregs and Th17 (47.8)
Authors: Zheng Song Guo , Lu Ling , Wang Julie , Brand David , Horwitz David , Shi Wei 
Published: January 2023

Abstract
TGF-ß induces the development of Foxp3+ regulatory T (iTreg) and IL-17-producing (Th17) cells based on the present cytokines. However, the signaling pathways involved in the differentiation of these cells are poorly defined. TGF-ß signals through Smad-dependent and -independent pathways to affect T cell responses. While others reported Smad3 is required for activity of the Foxp3 enhancer, our studies suggest that Smad3 is not essential for TGF-ß to induce Foxp3+ expression. In naïve CD4+CD25- cells isolated from either Smad3 KO or Smad2 conditional KO mice, TGF-ß was still able to induce TCR-activated T cells to express Foxp3 and developed suppressive activity, although the level of Foxp3 was slightly lower than induction in wild type cells. TGF-ß induced naïve CD4+ cells from wild type and Smad3-/- CD4+ to become Th17 cells in the presence of IL-6. Addition of retinoic acid (ATRA) increased iTreg differentiation and controlled Th17 development in both wild type and Smad3-/- mice. These results suggest that although the combined effects of Smad2 and Smad3 may be needed for the induction of iTreg and Th17 cells, Smad-independent signaling pathways are also required for these TGF-ß differentiation effects. (Supported by ACR REF Award and Outstanding youth Scientist Award from NSFC)
Tracking of individual autoreactive and regulatory T cells in Aire deficient TCR "mini" Foxp3-GFP mice (48.16)
Authors: Daniely Danielle Leigh , Ignatowicz Leszek 
Published: January 2023

Abstract
The presentation of tissue specific antigens (TSA) in the thymus is crucial in developing tolerant T cells and the lack thereof, leads to the development of autoimmunity (AI). Peripherally, autoreactive T cells (TA cell) that escape central tolerance can be controlled by FoxP3+ (TRcells). Mice deficient of the Aire gene lack Aire dependent TSA expression and develop organ-specific AI. It has been postulated that in the absence of Aire the diversity of TRcells positively selected is compromised. We propose to examine the effect of Aire on the T cell repertoire at the level of a single T cell clone, using an in vivo model (Aire-/-TCRminiFoxp3GFP mice) where Aire deficient mice express polyclonal, but miniature TCR repertoires. The T cells have a narrow αβ TCR repertoire composed of one transgenic TCR Vβ14+ chain and various TCRα chains produced by the rearrangements of the transgenic Vα2-Jα26,Jα2 mini-locus. The sequence of the CDR3 regions can be used as "tags" to follow the expansion of T cells and GFP driven by the FoxP3 promoter labels all TRcells. We show that irrespective of the mini repertoire, these mice develop multi-organ AI characterized by circulating autoantibodies and organ infiltrates. Analysis of individual TA and TRcell infiltrating organs show non-overlapping repertoires with the expansion of specific T cells. Further research will reveal if these clones are the tissue specific "culprits" responsible for this AI.