bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell-intrinsic adenosine A2A receptor signaling is required for T cell homeostasis and control of tumor growth (47.1)
Authors: Cekic Caglar , Sag Duygu , Linden Joel 
Published: January 2023

Abstract
Adenosine generated as a result of normal metabolic activity is elevated in response to tissue stress, damage, or hypoxia. By stimulating adenosine A2A receptors (A2ARs) adenosine links metabolic activity to regulation of normal physiological functions such as sleep, blood flow, and inflammation. Although stimulation of A2ARs on activated T cells and APCs acutely suppresses inflammation and immune killing of tumor cells, global A2AR deletion has variable effects on the growth rate of syngeneic tumors, suggesting that A2AR signaling has opposing effects on immune function. Here we show that A2ARs are required for homeostatic maintenance of naïve T cells. In global A2AR-deficient mice naïve T cells undergo apoptosis, which drastically lower their number in blood and in peripheral lymph nodes. Lymphoid deletion of A2ARs, adoptive co-transfer and mixed bone-marrow reconstitution experiments showed that cell intrinsic A2AR signaling is required for T cell homeostasis. A2AR signaling is also required for interleukin 7 to optimally facilitate T cell survival ex vivo. In mice injected with syngeneic melanoma cells, lymphoid-specific A2AR deletion decreases T cell numbers in the periphery and in the tumor, reduces the proportion of tumor infiltrating T cells with an activated/memory phenotype, and markedly accelerates tumor growth. The results indicate that homeostatic adenosine production and A2AR signaling are required in naïve T cell maintenance and immune defense against tumors.
Polyfunctional capacity of T cell function in older adults (47.10)
Authors: Canaday David , Burant Christopher , Banks Richard , Aung Htin , Hornick Thomas , Higgins Patricia 
Published: January 2023

Abstract
The precise polyfunctional capabilities of T cells from older persons are not well known. We determined the polyfunctionality of memory CD8+ and CD4+ T cell subsets using a 13-color flow cytometric assay that simultaneously analyzes IFN-gamma, TNF, MIP1-alpha, IL-2, and perforin expression after stimulation. PBMC from 37 older (mean age 82) and 30 younger (mean age 34) individuals were stimulated with a sub-maximal concentration of the mitogen SEB. Older adults were also assessed by the Fried frailty test. The proportion of highly polyfunctional cells that could perform 3, 4, or 5 functions was similar in the memory T cell subsets from older and younger individuals. The percentage of cells capable of performing each individual function had only small differences between the age groups. Within the older group however, polyfunctionality of central memory CD4+ and CD8+ T cells and CD8+ effector cells had in inverse correlation with frailty while not having a relationship with age. In conclusion, as a whole the frequency and polyfunctionality and mitogen-activated CD4+ and CD8+ memory T cell subsets in older individuals is preserved compared to the younger group. Therefore, the phenomenon of immunosenescence particularly in the non-frail elderly may not include the loss of capability and breadth of function of T cells if stimulated sufficiently. This may inform specific strategies to boost the older immune system.
Inducible costimulator (ICOS) negatively regulate programmed death-1 (PD-1) induced apoptosis of effector memory CD4 T cells under homeostatic condition (47.11)
Authors: Suvas Susmit , Channappanavar Rudragouda , Twardy Brandon 
Published: January 2023

Abstract
ICOS, a T cell specific costimulator, promote the survival of effector memory CD4 T cells whereas PD-1, an inhibitory molecule, can induce apoptosis of memory CD4 T cells. However, the role of these cell-surface associated accessory molecules in regulating each other function when co-expressed on a single cell is not well known. In this report, we demonstrate that naturally occurring effector memory like CD4 T cells in unmanipulated young (12 weeks) C57BL/6 mice either do not express PD-1 and ICOS (PD-1-ICOS-) or express PD-1 (PD-1+) or ICOS (ICOS+) or both molecules (PD-1+ICOS+) when measured by flow cytometery in the spleen. A similar trend was noted in the splenocytes obtained from aged (24 months) B6 mice but the proportion and number of PD-1+ICOS+ effector memory CD4 T cell pool was significantly higher in the aged mice in comparison to young B6 mice. While comparing the ability of these four subsets of effector memory CD4 T cells to undergo spontaneous apoptosis in vivo by Annexin V staining, we determined that PD-1+ICOS+ subset was least susceptible to spontaneous apoptosis. In vivo administration of anti-ICOS antibody given to unmanipulated aged B6 mice resulted in significantly increased proportion of apoptotic PD-1 expressing memory CD4 T cells when compared to isotype treated control group. Taken together, our results suggest a novel mechanism by which PD-1 expressing antigen specific effector memory CD4 T cells might survive under steady state condition.
PI3K/Akt pathway contributes to development of apoptosis resistance during differentiation of human macrophages by maintaining antiapoptotic Bcl-xL protein expression (48.7)
Authors: Kumar Ashok , Busca Aurelia , Saxena Mansi 
Published: January 2023

Abstract
Resistance to apoptosis is an important characteristic that human macrophages acquire during differentiation from monocytes. However, the intracellular mechanisms that mediate the development of resistance remain mostly unknown. We have used PMA-treated THP1 cells and MCSF-stimulated primary monocytes to generate human macrophages. By using chemical inhibitors for the PI3K and MAPK pathways, our results show that only pretreatment of cells before differentiation with the PI3K/Akt inhibitor LY294002 induced caspase dependent apoptosis that was associated with decreased expression of antiapoptotic Bcl-xL protein. These results were confirmed by inactivation of this pathway by Akt specific siRNAs. Moreover, this effect was specific if Akt was knocked down before inducing differentiation. Furthermore, Bcl-xL expression was found to be dependent on NFkB in differentiating macrophages. However, NFkB activation was prevented by LY294002 pretreatment, indicating that NFkB is responsible for Bcl-xL expression via PI3K/Akt signaling. Taken together, these results suggest that survival of macrophages is distinctly regulated during and after differentiation. A signaling pathway encompassing PI3K/Akt-mediated activation of NFkB plays a key role in survival of differentiating macrophages by specifically sustaining antiapoptotic Bcl-xL expression.
CD4+ T cells are necessary and sufficient to confer protection against C. trachomatis infection in the murine upper genital tract. (49.18)
Authors: Gondek David , Olive Andrew , Starry Georg , Starnbach Michael 
Published: January 2023

Abstract
Chlamydia trachomatis infection is the most common bacterial sexually transmitted disease in the United States. Chlamydia infections that ascend to the upper genital tract can persist, trigger inflammation, and result in serious sequelae such as infertility. However, current mouse models where the vaginal vault is infected with C. trachomatis do not recapitulate the course of human disease. These intravaginal infections of the mouse do not cause significant infection of the upper genital tract, do not cause persistent infection, do not induce significant inflammation, and do not induce CD4+ T cell infiltration. Here we describe a non-invasive transcervical infection model where we bypass the cervix and directly inoculate C. trachomatis into the uterus. We show that direct C. trachomatis infection of the murine upper genital tract stimulates a robust Chlamydia-specific CD4+ T cell response that is both necessary and sufficient to clear infection and provide protection against re-infection.
Conditional deletion of RANK in intestinal epithelial cells of mice results in loss of Peyer’s patch M cells and impaired acquisition of orally delivered antigen (49.2)
Authors: Rios Daniel , Knoop Kathryn , Kumar Nachiket , Tawde Suprita , Chablani Lipika , D'Souza Martin , Williams Ifor 
Published: January 2023

Abstract
Microfold (M) cells are antigen-sampling intestinal epithelial cells found in the follicle-associated epithelium (FAE) of Peyer’s patches (PPs). M cells initiate mucosal immune responses by transcytosis of particulate antigens for delivery to antigen-presenting cells that traffic through the intraepithelial pocket of M cells. We previously showed that RANKL from stromal cells in the subepithelial dome of PPs is necessary and sufficient for inducing M cell differentiation. To determine how selective loss of intestinal M cells affects host immune responses to antigens encountered in the gut lumen, we generated mice with a floxed allele of RANK deleted only in intestinal epithelial cells (IEC) by a villin-cre transgene (RANKΔIEC mice). The FAE of PP in RANKΔIEC mice lacked any cells expressing the M-cell marker GP2, proving that RANKL promotes M cell differentiation from intestinal stem cells via a direct action on RANK-expressing IEC. An OT-II T cell adoptive transfer model was used to analyze ovalbumin (OVA)-specific T cell responses 2 to 3 days after gavage with various forms of OVA. RANKΔIEC mice had compromised T cell responses to both soluble OVA and particulate OVA (OVA encapsulated in acid-stable microparticles prepared by spray drying). The RANKΔIEC mouse provides a first-of-its-kind mouse model for the specific assessment of the contribution of intestinal M cells to uptake of protein antigens and pathogenic microorganisms encountered in the intestinal lumen.
Anti-TBGL IgA antibody suggest mucosal immunity involvement in latent tuberculosis infection, which is frequently positive for anti-TBGL-IgG antibody. (49.28)
Authors: Hattori Toshio , Siddiqi Umme , Leano Susan , Chagan-Yasutan Haorile , Telan Elizabeth Freda 
Published: January 2023

Abstract
Anti-tubercular-glycolipis-IgG (TBGL-IgG) and -IgA (TBGL-IgA) elisa and interferon gamma release assay (IGRA) were done in healthcare workers (HCW, n=31) in Manila to study the immune responses in latent TB infection (LTBI). Forty eight percent (15/31) of the HCWs showed positive reactions in the IGRA indicating high incidences of LTBI in Manila. Eleven of 15 IGRA-positive HCWs had positive TBGL-IgG responses (categorical agreement 73%), whereas 5 of 16 QFT-negative subjects had positive TBGL-IgG responses (categorical agreement 68.7%). The overall κ value was 0.42, indicating a moderate association between the two assays (overall agreement: 71%; 95% CI: 0.10 ~ 0.73). The TBGL-IgG-positive proportions were also significantly different between the IGRA-positive and -negative groups of HCWs (P = 0.02). The TBGL-IgG+IgA double-positive response was shown only by IGRA-positive HCWs. A significant, positive correlation was observed between the IFN-γ levels and TBGL IgA titers in the IGRA-positive group (r = 0.74, P = 0.006) but not in the IGRA-negative group. There was no such association between the levels and TBGL-IgG titers in HCWs, although a tendency for a positive correlation was observed in the IGRA-positive HCWs (r = 0.43, P = 0.11). No association was observed between the IFN-γ concentrations in antigen stimulated IGRA-plasma and thr TBGL-IgG or -IgA titers. These findings suggest the involvement of mucosal immunity in LTBI.
Characterization of a DC Presenting a Microbial Polysaccharide to Regulatory T cells. (49.9)
Authors: Dasgupta Suryasarathi , Erturk-Hasdemir Deniz , Kasper Dennis 
Published: January 2023

Abstract
Bacteroides fragilis Polysaccharide A (PSA) is a unique commensal microflora molecule which has shown potent CD4+T cell mediated IL-10 dependent anti-inflammatory properties in various murine models. Little is known about how these immunoregulatory T cells are induced in order to control inflammation. We first observed that PSA dependent augmentation of regulatory T cells correlated with frequency of B220+CD11cint cells in MLN. We focused majorly on Plasmacytoid dendritic cells (PDCs), which have been implicated as tolerogenic DCs in other inflammatory situations. We observed higher expression of TLR2, a previously reported PSA receptor, in PSA treated PDCs compared to media control in vitro. Isolated PDCs from wild type compared to TLR2 deficient PDCs significantly augmented the liberation of IL-10 from CD4T cells in presence of PSA (p=0.0046), a process mediated by co-stimulators ICOSL and CD86. In a TNBS induced colonic inflammation model to study PSA mediated protection, the frequency of PDCs correlated significantly but inversely with cumulative colitis score (R2=0.4377, p=0.0002) suggesting an immunoregulatory role of these cells. Interestingly, neither protection nor change in PDCs was observed in TLR2-/-mice. In addition, PSA failed to protect mice when either PDCs were depleted or co-stimulators inhibited in vivo with monoclonal antibodies. This work suggests a tolerogenic or immunoregulatory role for PDCs most probably by generating regulatory features in T cells.
STAT4 isoforms are biomarkers in patients with inflammatory bowel disease (51.2)
Authors: Jabeen Rukhsana , Steiner Steven , Miller Lucy , Kaplan Mark 
Published: January 2023

Abstract
Crohn’s disease (CD) and ulcerative colitis (UC), the major forms of inflammatory bowel disease (IBD) in humans are characterized by chronic relapsing inflammation of the gastrointestinal tract (GI). Th1 and Th17 cells have been implicated as important mediators of IBD. Signal transducer and activator of transcription (STAT4) is critical for the development of Th1 cells and promotes IL-17 production from Th17 cells. STAT4 is expressed as two isoforms, a full-length STAT4α, and STAT4β that lacks the C-terminal transactivation domain. In a previous study we found that although both isoforms mediate inflammation in a mouse model of colitis, STAT4β seems more potent in generating tissue inflammation. With this we hypothesized that if STAT4β is more pro-inflammatory, ratios of the isoforms might change in disease. Compared to healthy controls, we observed increased STAT4β/STAT4α ratios in the peripheral blood mononuclear cells of UC and CD patients, correlating with the disease and ratios were normalized after patient treatment. Increased STAT4β/STAT4α ratios in GI biopsies of CD patients further confirmed that ratios correlate with the location and grade of inflammation. In contrast, we did not observe changes in STAT4β/STAT4α ratios in biopsy specimens from eosinophilic esophagitis (EE) patients. Collectively, these data indicate that STAT4 isoforms could be an important non-invasive biomarker in the diagnosis and treatment of IBD, and potentially other inflammatory diseases.
Adenosine Receptor 2A Agonist-Induced Tolerogenic Dendritic Cells Protect Mouse Kidney from Ischemia-Reperfusion Injury (52.2)
Authors: Li Li , Huang Liping , Ye Hong , Song Steven , Bajwa Amandeep , Lee Sang Ju , Jaworska Katarzyna J , Kinsey Gilbert , Day Yuan , Linden Joel , Lobo Peter , Rosin Diane , Okusa Mark 
Published: January 2023

Abstract
Dendritic cell (DC)-mediated nature killer T (NKT) cell activation is critical in initiating the immune response following kidney ischemia-reperfusion injury (IRI). Adenosine 2A receptor (A2AR) agonists protect kidneys from IRI through their actions on bone marrow (BM)-derived leukocytes. We hypothesized that A2AR agonists attenuate IRI by tolerizing DCs and preventing NKT cell activation. ATL313 attenuated kidney IRI in WT mice but not in mice deficient of DC A2ARs (CD11c-CreAdora2a-/-). BM-derived DCs were activated by ex vivo incubation with alpha-galactosylceramide (aGC)±ATL313 (1nM), washed and adoptively transferred into naïve WT mice 2 days before kidney IRI. ATL313-treated aGC-loaded WT DCs (DC-aGC-ATL313) but neither Adora2a-/- DC-aGC-ATL313 nor DC-aGC protected kidney function following IRI. Co-culture of NKT cells with DC-aGC-ATL313 caused less IFN-g production than with DC-aGC. ATL313 down-regulated OX40L and CD40 and up-regulated B7-DC expression but had no effect on DC surface and intracellular CD1d/aGC complexes. DC-aGC-ATL313-mediated kidney protection was not due to Treg cell expansion, but was in part due to IL-10, as IL-10mRNA level increased and IL-10 neutralization reversed the protective effect of DC-aGC-ATL313; DC-aGC-ATL313 also up-regulated PD-1 expression on co-cultured Tregs. We conclude that A2AR-induced tolerized DCs, which suppressed NKT cell activation in vivo, provide a unique and potent cell-based strategy to attenuate organ IRI.
Higher antioxidant capacity determines the survival of class I restricted antigen specific CD4 T cells in comparison to CD8 T cells (52.20)
Authors: Kesarwani Pravin , Mehrotra Shikhar 
Published: January 2023

Abstract
CD8+T cells are known to be effector cells, however, recent reports illustrate CD4+T cells as effectors capable of controlling tumor growth. Due to differences in specificity of these two T cell subsets, a comparison in an antigen specific manner has not been possible. Utilizing the TCR transgenic h3T (human TIL derived Tyrosinase TCR, specific for human tyrosinase epitope368-375) mice with class I restricted CD8 and CD4 T cells. We investigated the differences in class I restricted CD4 and C8 T cells in terms of differential signaling and cell death. Our results demonstrate that despite the lower cytolytic capacity class I restricted CD4 T cells were equally capable of controlling human MEL-624 cell in a xenograft model. Vβ12+CD4+ in comparison to Vβ12+CD8+ cells upon antigen specific re-stimulation showed reduced cell death and increased resistance to oxidative stress induced cell death. Our results also demonstrate that Vβ12+CD4+ cells exhibit higher cell surface thiols, higher mitochondrial membrane potential and lower ROS in comparison to Vβ12+CD8+ cells. Further we found that CD4+T cells show higher level of antioxidant enzymes such as SOD1, GPX4, CYBA and antiapoptotic molecule BCL2. In addition CD4+T cells had higher levels of micro RNA-let-7 (down regulates Myc and FasL). These results suggest that CD4+T cells have less lytic capacity they are also less susceptibility to cell death in comparison to CD8+ T cells due to innate differences at oxidative capacity.
CD11b/CD18 ligation on monocyte-derived dendritic cells dampens human Th17 cell responses (52.6)
Authors: Nowatzky Johannes , Khan Shaukat , Manches Olivier , Bhardwaj Nina 
Published: January 2023

Abstract
Manipulating monocyte-derived DC (moDC) to alter effector T cell responses is an important strategy for the development of suppressive immunotherapy. We have previously shown that the ligation of CD11b/CD18 on moDC decreases the secretion of the Th17-skewing inflammatory cytokines IL-1β and IL-6, but maintains “immunosuppressive” TGF-β1. Here, we hypothesized that this “tolerogenic” DC-profile would diminish Th17 responses in peripheral human T cell populations. Healthy donor PBMC were differentiated into moDC in IL-4, GM CSF-supplemented media for 5 days. CD11b/CD18 on moDC was targeted via a bead-based surrogate system developed in our lab. Irrelevant IgG, or avb5, and beads without antibodies were used as controls. DC were stimulated with LPS and MDP or PGN or not stimulated, and then co-cultured with enriched CD4+ human T memory cells. IL-17 secretion was monitored per CBA after 24 hours and/or 4 days, and Th17 frequency assessed by ICS following restimulation with PMA/Ionomycin after 2 weeks. LPS/MDP or PGN-stimulated moDC induced significant increases in co-culture supernatant IL-17 levels and CD4+ Th17 cell frequencies (up to15%). Strikingly, these changes were significantly reduced in CD11b/CD18-ligated DC/T cell conditions, showing reversal of this NOD2/TLR4 or TLR2-mediated expansion effect though ligation of CD11b/CD18 on moDC.
Involvement of Type I Interferon pathway in generating antibody responses elicited by DNA vaccination. (52.7)
Authors: Suschak John , Wang Shixia , Fitzgerald Kate , Lu Shan 
Published: January 2023

Abstract
Recent human study data suggests that DNA immunization can substantially enhance the protective antibody responses elicited by conventional influenza vaccines, but the mechanism of such actions is completely unknown. The current study was designed to explore the roles of innate immunity in regulating acquired immunity elicited by influenza vaccines. Innate pattern recognition receptors (PRRs), and their downstream signaling molecules, were investigated for their effect on DNA vaccination. Of particular interest was the type I interferon (IFN) pathway and its effects on the antigen-specific antibody response. Wild type C57BL/6 mice and selected Interferon Regulatory Factors (IRFs) knockout mice were immunized with DNA vaccines expressing the hemagglutinin antigen (HA) of H1 subtype influenza virus. Mouse serum anti-H1HA antibodies and non-antigen specific cytokine profile analysis showed that deletion of the IRF3 pathway alone did not result in a significantly decreased antibody response but deletion of both the IRF3 and IRF7 pathways led to a dramatic reduction of the anti-HA antibody response. Interestingly, deletion of IL-1 signaling did not significantly affect the anti-HA antibody responses. These results suggested that the IFN pathway does play an important role in shaping the antigen specific antibody response to DNA vaccines and may require the involvement of more than one key regulatory molecule.
Interruption with TNFα/TNFR1 function impairs host immune response against cutaneous vaccinia virus infection (52.8)
Authors: Tian Tian , Dubin Krista , Jin Qiushuang , Qureshi Ali , King Sandra , Liu Luzheng , Jiang Xiaodong , Murphy George , Kupper Thomas , Fuhlbrigge Robert 
Published: January 2023

Abstract
One strategy adopted by vaccinia virus (VV) to evade the host immune system is to encode homologs of TNF receptors (TNFR) that block TNFα function. The response to VV skin infection under conditions of TNFα deficiency, however, has not been reported. We found that TNFR1-/- developed larger skin lesions with higher virus levels after VV scarification. Following their recovery, these TNFR1-/- mice were fully protected against lethal VV intranasal challenge, suggesting their effective memory immune response. A functional systemic immune response of TNFR1-/- mice was further demonstrated by enhanced production of VV-specific IFNγ and CD8+ T cells in spleens and draining lymph nodes as well as efficient T cell skin homing. Interestingly, bone marrow (BM) reconstitution studies using WT BM →TNFR1-/- mice, but not TNFR1-/- BM → WT mice, reproduced the original results seen in TNFR1-/- mice, indicating that TNFR1 deficiency in resident skin cells, rather than hematopoietic cells, accounts for the impaired cutaneous immune response. Similar phenotype was also found in in TNFα-/- mice following VV scarification while both WT BM→ TNFα-/- mice and TNFα-/-BM →WT mice developed significantly larger skin lesions with higher virus counts than the control chimeric mice.Therefore, while the target of TNFα action is restricted to skin stromal components, the source of TNFα produced in response to VV infection would appear to include both hematopoietic cells and radioresistant skin elements.