bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulmonary egress of CD8 T cells during influenza A virus infection. (49.10)
Authors: Jennrich Silke , Lee Michael , Dewberry Kristofer , Debes Gudrun 
Published: January 2023

Abstract
The capacity to migrate to and accumulate at infected sites is a requirement for antiviral effector functions of CD8 T cells. Memory/effector T cells efficiently enter sites of infection from the blood and subsequently leave the site via the afferent lymph. While T cell exit from extralymphoid tissue is regulated by the chemokine receptor CCR7 and alternative chemoattractant signals, it is controversial if effector T cells exit from the lung during acute respiratory infection. Here, we found that pulmonary T cells from influenza virus infected mice egress from the inflamed lung and migrate into draining lymph nodes. In addition, in vitro polarized (CD8+) Tc1 effector cells with the ability to protect against lethal influenza virus challenge were also able to egress from infected lungs upon intranasal transfer. Pulmonary egress of Tc1 cells was blocked by inhibition of chemoattractant signaling with pertussis toxin and significantly reduced by CCR7 deficiency. Our data demonstrate that effector T cell exit from the infected lungs is an active process, mediated by T cell expressed CCR7. We suggest that local T cell effector function and efficiency of host defense against influenza virus infection is controlled by the regulated expression of T cell exit receptors such as CCR7.
Route of priming regulates access to residual antigen and migration of memory T cells (49.12)
Authors: Jelley-Gibbs Dawn , Winfrey Carolyn , Woodland David 
Published: January 2023

Abstract
Memory T cells resident in peripheral tissues are key to establishing protective immunity to pathgens. There exist seemingly paradoxical concepts in the understanding of mechanisms regulating tissue-specific migration of CD8 memory T cells. One concept is that tissue-specific homing is imprinted by exposure to environmental factors during T cell priming. A contrasting concept is that memory T cells acquire tissue-specific homing properties through continued maturation in the periphery. Our mouse models of respiratory virus infection demonstrate that continued recruitment of CD8 T cells to the airways during steady-state memory is mediated by sequential events. Initial priming of CD8 T cells in the lung draining lymph node imprints memory CD8 T cells with the capacity to access residual antigen depots. Stimulation by residual antigen in the weeks to months following resolution of infection then promotes continued maturation and airway migration of CD8 T cells during steady-state memory. Interestingly, despite the formation of residual antigen depots following intraperitoneal, subcutaneous, or intramuscular infection, the resulting memory T cells ignore this maturation stimulus and fail to migrate to the airways despite exposure to lung inflammation. We hypothesize the site of priming is critical for imprinting memory T cells with the ability to access the additional signals required for continued maturation and effective migration of memory T cells to peripheral tissues.
Do immunostimulatory defective viral genomes arise during natural infections? (49.16)
Authors: Tapia Karla , López Carolina 
Published: January 2023

Abstract
The generation of defective viral genomes (DVGs) during the replication of viruses in vitro has been described for many different viruses including influenza, vesicular stomatitis and rabies. DVGs are truncated forms of the standard virus genome that are unable to replicate due to the lack of a functional viral polymerase. We have shown that DVGs have a potent ability to elicit the activation of dendritic cells in vitro demonstrating their exceptional capacity to trigger innate immunity. The presence of DVGs in viral preparations has been broadly correlated with protection against lethal doses of viruses. It was recently shown that RIG-I predominantly binds DVGs during infections with Sendai virus. The role of DVGs during natural infections is not known. Infection of bone marrow dendritic cells with different strains of Sendai virus showed that DVGs of different sizes are detected in all the viral preparations. In addition, infection with a Sendai virus strain that had been depleted of DVGs results in DVG generation at late points after infection correlating with the peak of viral replication. Interestingly, in mice infected with Sendai virus lacking DVGs we could also detect the appearance of DVGs at late times of infection. Together, these results show that DVGs can arise during the course of a natural virus infection stimulating exciting questions regarding their role stimulating anti-viral immune responses.
Cytolytic CD4 cells in the lungs of influenza-infected mice (49.17)
Authors: Marshall Nikki , Swain Susan 
Published: January 2023

Abstract
CD4 cells have been shown to acquire cytolytic activity (ThCTL) and demonstrate MHC class II-restricted killing of infected and transformed cells. We have identified a striking ThCTL subset in the lungs of influenza-infected mice that expresses high levels of Granzyme B, CD103 integrin, and CD107a and CD107b, markers of degranulation. This subset is not found in the spleen or lymph node. The ThCTL utilize a perforin-mediated mechanism to kill antigen-specific class II targets, and may play a role in killing influenza-infected airway epithelium which express high levels of MHC class II expression during influenza infection. ThCTL in the lung developed in mice deficient in Th1 polarizing cytokines IFN-γ and IL-12, further supporting their claim to being a unique subset of CD4 T cells. We are currently investigating the role of ThCTL in protection against influenza and the ability of ThCTL to develop into memory.
Apoptosis is necessary for functional T cell memory after influenza infection (49.19)
Authors: Thomas Paul , Dillon Christopher , Green Douglas , Sturm Oliver 
Published: January 2023

Abstract
Apoptosis can play a central role in the response to intracellular infections, both in the regulation of innate and adaptive immune responses and in the survival of the pathogen-infected cell. We investigated the effect of apoptosis in the response to influenza in various apoptosis deficient mouse models (Bim-/-, Bcl-2 and Akt tg) in vivo. Quantification of CD8 T-cells specific for immunodominant influenza epitopes (DbNP366, Db PA244, KbPB1703) revealed an increase in percentage and absolute CD8+ T cell numbers in the Akt tg, Bcl2 tg and Bim-/- primary, memory and secondary CD8+ T cell responses. The most striking effect was found in the Bim-/- model: a total ablation of the contraction phase after the CD8+ T cell response, leaving the number of flu specific memory CD8+ T cells abnormally high. Surprisingly, the immunodominance hierarchy in the memory Bim-/- response resembles that of a recall response (NP&gt;&gt;PA≈PB1). Their recall potential seemed blunted on a per cell basis compared to recall infections in wildtype mice, but after competitive adoptive transfer, the intrinsic recall division potential between the two memory cell populations was identical. However, Bim-/- CD8 T cells proved to be functionally deficient by cytokine production and effector activity, indicating a defect in the quality of memory. Thus, Bim-/- mediated contraction plays a role in selecting a memory precursor population with effector, rather than division, potential.
Development of Th17 and Treg cells during influenza viral infection in neonatal mice. (49.23)
Authors: Hoskins Samantha , Lines Louise , Garvy Beth 
Published: January 2023

Abstract
T cells in the neonatal lung are less activated than in adults and do not infiltrate the alveolar spaces in response to influenza virus infection. TGFβ is elevated in the lungs of neonatal mice, and since neonatal mice do not respond with a typical Th1 response, the Th17 and T regulatory (Treg) cells were evaluated. Neonatal mice had similar CD4 T cells expressing IL-17A compared to adults in the lung during viral clearance. In an adoptive transfer of adult and neonatal CD4 T cells into adult T cell receptor knockout mice (TCR-/-), neonatal T cells were able to enter the airways but failed to expand as robustly as adult T cells. In this model, neonatal CD4 T cells expressed more IL-17A than adult T cells and this coincided with increased numbers of neutrophils in the airway. Depletion studies will be used to examine the role of IL-17A and neutrophils in the clearance of influenza virus. In addition to a robust Th17 response, neonatal mice had higher levels of Tregs than adults, and these elevated levels persisted during influenza viral infection. Upon depletion of Tregs by anti-CD25 antibody, neonatal T cells still did not infiltrate into the alveolar spaces during an influenza viral infection. However, the anti-CD25 treated mice had a higher body weight and larger lymph nodes. To determine whether Tregs are responsible for the delayed viral clearance seen in neonatal mice, cytolytic T lymphocytes will be examined in neonatal mice without Tregs and plaque assays performed.
Rhinovirus has the unique ability to activate CD4 and CD8 T-cells, in the absence of Antigen-Presenting Cells (49.26)
Authors: Ilarraza Ramses , Wu Yingqi , Adamko Darryl 
Published: January 2023

Abstract
We hypothesize eosinophils (EOS) are key effector cells in asthma exacerbations caused by virus.We have shown that T-cells incubated with airway viruses activate eosinophil degranulation in vitro,after antigen-presentation (AP).Our recent data suggests Rhinovirus (RV) has the unique ability to activate T-cells directly.METHODS.Human blood monocyte-derived dendritic cells (moDC) were cultured with Respiratory Syncytial virus (RSV) or Rhinovirus (RV),washed and autologous T-cells and EOS were added.To inhibit AP,some moDC were treated with chloroquine during virus exposure.Also,T-cells alone (CD4+,CD8+,or mixed) were exposed to virus.Proliferation was measured by BrdU-ELISA and apoptosis by flowcytometry.EOS cysteinyl-leukotriene (Cys-LT) release was measured by ELISA.We also used agonists for TLR (2,3,4,7,8).RESULTS.RV induced Cys-LT release from EOS cultured with T-cells (n=6,p&lt;0.001).Virus-moDC induced T-cell proliferation but,unlike RSV,RV was chloroquine-insensitive (n=5,p&lt;0.001).T-cells alone showed proliferation (n=3-7,p&lt;0.01) and apoptosis (n=4,p&lt;0.001) with RV but not with UV-inactivated RV,or RSV.Proliferation was time-(n=3,p&lt;0.01) and dose-(n=2) dependent.CD8 T-cells showed higher proliferation (n=2) and cell death (n=4,p&lt;0.001) than CD4.TLR agonists alone did not induce T-cell proliferation.CONCLUSIONS.Results suggest RSV and RV induce T-cell activation differentially.Our data may help understand why RV is a potent inducer of asthma exacerbation in allergic patients
Suppressor T cell exosomes via miR-150* and antigen specific Ig light chains. (50.13)
Authors: Askenase Philip 
Published: January 2023

Abstract
Tolerance in contact sensitivity (CS) is due to CD8+ suppressor T cell (Ts) released factor (TsF) that is phenol chloroform extractable (PCE), in RNA fraction of Qiagen DNA/RNA separation column, sensitive to RNase A, not DNase nor trypsin, and also sensitive to RNase III; a property of double stranded RNA (dsRNA) like miRNA. Sizing electrophoresis indicated the active inhibitory RNA was about 75bp; the size of pre-miRNA. TsF RNA also inhibited in vitro IL-2 responses of T cell lines. We concluded that the small suppressive dsRNA was in the miRNA family TsF RNA is transported systematically in vivo in exosomes in the blood plasma of Ts donors. Remarkably, the exosomes act antigen (Ag) specifically due to surface coat of Ag-specific immunoglobulin free light chains, likely derived from activated B-1 B cells, and absorbed to receptors on the exosome surface. Ag specificity of the exosomes that eluted from the Ag column provided enriched exosome RNA for cDNA cloning and deep sequencing to identify candidate miRNA-150*. We postulate that the suppressive Ag-specific exosomes act systemically in an endocrine manner, via the blood, to target Ag specific effector T cells at distant sites, and inhibit their function via transfer of the inhibitory miRNA. This is the first demonstration of systemic immunoregulation by exosomes delivering inhibitory miRNA Ag specifically from donor suppressor T cells to distant target effector T cells in an endocrine manner.
Bariatric surgery regulates tissue specific inflammation in high fat diet-induced obese mice (50.14)
Authors: Yin Dengping , Gao Qiang , Ma Lian Li , Yan Wenwei , Williams Phillip , Wasserman David , Abumrad Naji 
Published: January 2023

Abstract
Visceral fat deposition induces chronic low grade inflammatory reactions and insulin resistance. However, surgical removal of visceral fat fails to reverse metabolic disease, suggesting that intrahepatic fat, not visceral fat, may be linked with metabolic complications of obesity. Using gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) mouse models, we examined whether the effects of bariatric surgery in the treatment of obesity and insulin resistance were associated with the regulation of inflammation in visceral adipose tissue (VAT) and liver in DIO mice. SG produced weight loss and improved glucose tolerance in the short term, and RYGB, but not SG, resulted in sustained prevention of weight gain and impaired glucose tolerance and decrease in phosphorylation of IRS-1/Ser307 in liver and muscle. RYGB, SG and caloric restriction inhibited NF-kappaB activation in VAT and muscle. RYGB and SG decreased circulating insulin, inhibited proinflammatory cytokine transcription in VAT and reduced CD11b macrophages in liver and in VAT. However, RYGB, but not SG, inhibited CD11c+ cells (-53%) and promoted CD206+ cells (+79%) in liver but not in VAT. RYGB and SG inhibited CD4+/IFNgamma+ subset (-50% and -44%) in DIO VAT, and only RYGB enhanced CD4+/IL-10+ subset (+100%) in DIO liver. We conclude that the improvements in insulin resistance associated with RYGB and SG appear to be modulated by the inhibition of inflammation in a tissue specific manner.
TLR4-activated B cells out-compete TLR9-activated B cells to establish peripheral tolerance (50.16)
Authors: Matheu Melanie , Su Yan , Greenberg Milton , Parker Ian , Scott David , Cahalan Michael 
Published: January 2023

Abstract
Antigen presentation by B cells can generate either long-lived antigen-specific CD4+ T cell tolerance or activate T cells for additional B cell help during the humoral response. In our model, both naïve and LPS-activated B cells mOVA B cells expressing ovalbumin induced long-lived peripheral T cell tolerance, suppressing OTII T cell proliferation and T-cell-dependent antibody production in vivo. In contrast, CpG-activated mOVA B cells did not induce tolerance to OVA. Using two-photon microscopy we compared T-B cell interactions in the lymph node during tolerance induction or priming of OTII T cells mOVA B cells. Naïve, LPS- or CpG-activated mOVA B cells were individually capable of establishing long-lived interactions with OTII-T cells. Disruption of CTLA-4 / B7 interactions prevented establishment of long-lived T-B cognates and inhibited tolerance induced by LPS-treated B cells in vivo. In competition experiments with co-transferred LPS- and CpG-activated B cells, LPS- activated B cells dominated cell-cell interactions and were capable of establishing tolerance. In addition, tolerogenic LPS-activated B cells were capable of physically disrupting pre-established CpG-activated mOVA T-B pairs, exhibiting directional motility towards pre-established CpG-OTII pairs prior to disruption. Our findings demonstrate that LPS-activated B cells can act early in an immune response to establish tolerogenic dominance in the presence of priming CpG-activated B cells.
GRAIL targets CDC37 to maintain CD4 T cell unresponsiveness (50.9)
Authors: Whiting Chan , Su Leon , Lin Jack , Lineberry Neil , Fathman C. 
Published: January 2023

Abstract
It has long been appreciated that CD4 T cells are held in G1/S cell cycle arrest. How this is initially achieved, and then lost upon activation, is not well understood. Recent studies from our lab have demonstrated that the E3 ligase, GRAIL (gene related to anergy in lymphocytes, also known as RNF128), is expressed only in late stage QA2 positive thymocytes upon their exit from the thymus, and that its expression holds CD4 T cells in cell cycle arrest. GRAIL is not only expressed in late stage thymic migrants, but in resting CD4 T cells as well as in anergic CD4 T cells suggesting that GRAIL might be involved in holding CD4 T cells in cell cycle arrest. Using a novel E3 substrate screen, we identified cdc37 (a G1-specific cyclin) as a target of GRAIL mediated ubiquitination. Consistent with this idea, GRAIL expression leads to diminished cdc37 expression and maintained cell cycle arrest upon activation. Inversely, primary CD4 T cells lacking GRAIL have higher levels of cdc37 compared to wildtype T cells in resting conditions and allow full activation with TCR stimulation in the absence of costimulation. These data suggest that GRAIL ubiquinates and targets cdc37 for degradation and thus, maintains CD4 T cells in G1/S cell cycle arrest. These data also highlight a role for cdc37 in GRAIL-mediated cell cycle regulation and CD4 T cell proliferation. The activated CD4 T cells reacquire GRAIL expression and return to the resting G1/S interphase by unknown mechanisms.
Innate immune agonists conjugated to nanolipoproteins elicit robust inflammatory responses in mouse macrophages: implications for host-based therapeutics. (52.10)
Authors: Rasley Amy , Blanchette Craig , Fischer Nicholas , El-Etr Sahar , Loots Gabriela , Corzett Michele , Thomas Cindy , Urbin Salustra 
Published: January 2023

Abstract
Modulation of the innate immune system has the potential to provide transient, non-specific protection from a variety of infectious organisms. We hypothesize that combinatorial formulations of synthetic innate immune agonists may significantly enhance protection over single-agonist formulations. To readily incorporate multiple, chemically diverse agonists onto a single particulate platform for co-localized delivery, nanolipoprotein particles (NLPs) will be used. NLPs are discoidal, nanometer-sized particles comprised of self-assembled phospholipid membranes and apolipoproteins, analogous to reconstituted HDLs. NLPs assembled with human apolipoproteins have been used for numerous biotechnology applications, including membrane protein solubilization, drug delivery, and diagnostic imaging. NLPs can be functionalized to incorporate myriad agonists, including CpG-containing oligonucleotides, monophosphoryl Lipid A, muramyl dipeptide, flagellin, and an LL-37 analog. Development of NLPs incorporating CpGs and MPLA will be described, as well as preliminary results from in vitro analyses, including quantitative inflammatory cytokine secretion, cellular cytotoxicity, and cellular localization. Our data indicate that agonist:NLP constructs are internalized by macrophages, are immunostimulatory, and induce low levels of cellular cytotoxicity.
The lipid raft hinders antibodies from binding to the external segment of the membrane-anchor peptide of mIgA (52.19)
Authors: Hung Alfur , Chen Jiun-Bo , Lu Chien-Sheng , Chen Nien-Yi , Yu Hui-Ming , Chang Tse Wen 
Published: January 2023

Abstract
The mIgA is associated with Igα/Igβ as the B cell receptor (BCR) complex on mIgA-expressing B cells. The α chain of mIgA (mα), comparing to the α chain of secreted IgA, contains an extra C-terminal membrane-anchor peptide, which encompasses an extracellular, a transmembrane, and an intracellular segments. The extracellular segment, referred to as mIg isotype-specific (migis-α) segment or extracellular membrane proximal domain (EMPD), has been proposed as a specific antigenic site for isotype-specific targeting of mIgA-expressing B cells by antibodies. In this study, we developed several anti-migis-α mAbs, such as MAb 29C11, which were specific to a peptide segment toward the N-terminal of migis-α. The mAbs bound strongly to synthetic peptides of migis-α and various recombinant proteins containing migis-α in ELISA. However, the mAbs did not bind to mIgA on B cell lines strongly in fluorescence flow cytometric analysis. After disrupting the lipid raft integrity of the B cells by a typical cholesterol extraction procedure, the mAbs could then bind to the treated B cells strongly. Immunopricipitation analysis with the mAbs indicated only when the B cell lines were solubilized by sufficiently strong detergents, such as sodium dodecyl sulfate (SDS), the mIgA could be pulled down by the mAbs. These results suggest that the migis-α region of mIgA in the BCR is associated with the lipid raft. Future studies will investigate inhibitory effects of mAb 29C11 on mIgA-expressing B cells.
Amplification of long-lived polyfunctional memory CD8 T cells by prime boost vaccination is dependent on high precursor frequencies. (52.29)
Authors: Fraser Kathryn , Schenkel Jason , Vezys Vaiva , Masopust David 
Published: January 2023

Abstract
Memory CD8 T cell quantity and quality are related to their capacity to protect against infection. We have shown that heterologous prime boost vaccination results in abundant effector memory CD8 T cells due to minimized contraction of tertiary effector cells. Critical questions include, 1) why are tertiary effector CD8 T cells so efficiently recruited into the memory pool, and 2) does repeated boosting result in functionally exhausted memory cells? We demonstrate that enhanced recruitment into the tertiary memory pool is dependent upon high antigen-specific precursor frequencies prior to boosting and correlates with retention of CD127 and Bcl2 during clonal expansion and a more modest number of cell divisions. Despite enrichment of an effector memory phenotype at the population level, resulting tertiary memory cells were highly functional, as measured by cytokine secretion potential, antigen sensitivity, and proliferative potential. However, reducing the precursor frequency prior to boosting resulted in effectors that undergo a greater number of divisions and experience large changes in global gene expression patterns, reduced expression of CD127 and Bcl2, reduced probability of recruitment into the memory pool, and reduced functionality of resulting memory. These results give insight into the parameters that regulate memory CD8 T cell development and define conditions under which immense quantity can be achieved while either preserving or diminishing protective potential.
Innate immune responses to açaí polysaccharides (52.31)
Authors: Holderness Jeff , Freedman Brett , Schepetkin Igor , Kemoli Sharon , Hedges Jodi , Jutila Mark 
Published: January 2023

Abstract
The açaí fruit has become a popular nutritional supplement with anecdotal claims of increasing immunity. Previous works by others show that the procyanidin fraction of this supplement induces immune activation. We expand upon this work to identify an endotoxin-free, purified polysaccharide fraction in Açaí fruit that can also stimulate immune responses. Treatment with Açaí polysaccharides results in activation of the innate immune system, particularly γδ T cell and monocyte cell activation. Responses include: TNFα, IL-6, and IL-10 cytokine production, γδ T cell activation (CD69/IL-2Rα expression), ROS production, as well as myeloid cell recruitment/activation and IL-12 secretion in the lung after i.t. delivery. This response to Açaí polysaccharide is at least partially mediated by the polysaccharide receptor, Dectin-1. Unlike fungal polysaccharide recognition, which typically utilizes TLR2 as a co-receptor, our studies suggest that the lung immune response to Açaí polysaccharides is TLR2-independent and instead may require TLR4.