bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Aryl hydrocarbon receptor and the effect of selective AhR modulators on T cell differentiation (P1201)
Authors: Mohinta Sonia , August Avery , Perdew Gary 
Published: January 2023

Abstract
The physiological role of AhR, particularly in immune response remains a key question after identification of AhR as an essential transcription factor for Th17 differentiation. Selective AhR modulators (SAhRMs) are a recently identified class of compounds that are capable of binding to AhR and repress cytokine- driven gene expression. These compounds are interesting therapeutically as they can be used to inhibit Dioxin Response Element (DRE)-mediated while inducing anti-inflammatory responses. Under non-skewing conditions, AhR agonist beta-naphthoflavone (BNF) enhances IL-17A production whereas SGA-360 an inhibitor suppresses it. Under Th17 skewing condition, AhR agonist BNF enhanced Th17 differentiation whereas AhR antagonist GNF and partial antagonist SGA-360 suppressed it. Interestingly, under Treg skewing condition the antagonists enhanced the Foxp3 expression, suggesting that such compounds have therapeutic potential in autoimmune disease by modulating the Th17/Treg balance. We have also examined AhR antagonists after disease development in a murine model of Th17 mediated disease, hypersensitivity pneumonitis mediated by Staphylopolyspora rectivirgula (SR). We find that these antagonists suppress AhR activity and induce IL-4, suggestive of a shift in T helper lineage. This suggests that SAhRMs may be useful in modulating AhR activation to regulate Th17/Treg balance, and that AhR selective ligands have potential for use as therapeutics in Th17 mediated diseases.
Complex role for Interleukin-2 inducible T-cell kinase in T helper differentiation and effector function in vivo (P1204)
Authors: Kannan Arun , Butcher Barbara , Kim Do-Geun , Lee Yong , Bynoe Margaret , Denkers Eric , August Avery 
Published: January 2023

Abstract
T helper responses are critical for a productive immune response but an inappropriate response results in inflammatory and autoimmune disorders. The tyrosine kinase ITK has been shown to regulate the development of Th2 responses. Here, we show that ITK regulates Th1/Th17 responses as well. We find that Itk-/- mice are more susceptible to infection by Th1 inducing intracellular pathogen T. gondii, with generation of fewer antigen specific Th1 cells in vivo and fewer effector cells ex vivo upon antigen re-challenge. Transfer of WT CD4+ T cells confers protection against infection in Itk-/- mice. Furthermore, WT but not Itk-/- CD4+ T cells can promote the survival of Rag-/- mice infected by T. gondii. Additionally, the absence of ITK is protective during Th1/Th17 mediated Experimental Autoimmune Encephalomyelitis (EAE) with fewer pathogenic Th1 and Th17 effector cells in the periphery. Furthermore, transfer of Itk-/- CD4+ T cells into Tcra-/- mice results in lower severity of EAE compared to mice that receive WT cells suggesting that Itk-/- CD4+ T cells are intrinsically less pathogenic. Finally, using mice that express an analog sensitive mutant of ITK (ITKas) we show that temporally inhibiting the kinase activity of ITK with a genetically selective small-molecule inhibitor impairs development of Th1, Th2, and Th17 lineages. This work has implications for understanding ITK as a therapeutic target for Th2 mediated inflammatory and Th1/Th17 mediated autoimmune disorders.
Early effector T helper cells are precursors to both terminal effectors and memory T cells (P1207)
Authors: Opata Michael , Carpio Victor , Obiero Joshua , Dillon Brian , Stephens Robin 
Published: January 2023

Abstract
Effector memory CD4+ T cells (Tem) are important for protection from many chronic infections, but their development is poorly understood. While IFN-γ+ effector T cells (Teff) can survive into the memory phase in infection, it is not clear if mature Teff generate Tem, or if memory T cells diverge from Teff early after activation, as suggested for central memory T cells (Tcm) by data in model antigen systems. However, we have shown that both Tem and Teff are continuously generated from Tcm in chronic malaria infection. In the current study, we identified phenotypic subsets defining the gamut of activation of Teff using malaria-specific B5 TCR transgenic and IFN-γ reporter mice. We demonstrate that all Effector subsets (Early, Middle and Late) divide, and make IFN-γ in Plasmodium chabaudi infection, with IFN-γ+ TeffMid dominating expansion. We have shown by adoptive transfer that only TeffEarly have the potential to differentiate into the Middle and Late subsets, while TeffMid express low levels of anti-apoptotic Bcl-2, and high levels of Fas and PD-1, suggesting terminal differentiation. TeffLate express high levels of the Th1 factors T-bet and RUNX3, but are highly apoptotic. Of these subsets, only the less-differentiated TeffEarly subset survives to become memory cells (both Tcm and Tem) in naïve recipients. Our data suggest that TeffEarly are the elusive CD4+ precursor to memory and will accelerate the study of T cell mediated vaccine protection from the earliest stages.
Spatial and temporal regulation of interleukin 4 and interleukin 13 expression identified by dual reporter mice. (P1129)
Authors: Kyle Ryan , Robinson Marcus , Plunkett Catherine , Mearns Helen , Ochiai Sotaro , Tang Shiau Choot , Forbes-Blom Elizabeth , Chen Xi , Paul William , Le Gros Graham 
Published: January 2023

Abstract
Type II immune responses are associated with protection against helminth infections, as well as the pathology of allergic diseases that are initiated against innocuous antigens. Two integral cytokines associated with type II immunity are interleukin (IL-)4 and IL-13. The 4C13R transgenic dual reporter mouse has been created to allow identification of IL-4 and IL-13 producing cells by the production of two intracellular fluorescent molecules, AmCyan and DS-Red respectively. The expression of the distinct reporter proteins are under the normal transcriptional control of the Il4 or Il13 genes. This technology allows for the analysis of in situ IL-4 and/or IL-13 production by the relevant differentiated immune cell types without any effect on the endogenous cytokine genes or their effector activities in the mouse. Using this reporter system we have identified that in vitro generated CD4+ Th2 cells have divergent expression of IL-4 and IL-13, suggesting cytokine specific Th2 subsets. Additionally, IL-13 expression is delayed compared with IL-4 in this system. Reporter expression in vivo has also highlighted that IL-4/IL-13 double producers are only a subpopulation of CD4+ T cells, and cytokine expression profiles differ significantly between lymph node and effector tissues during type II responses. Studying the expression and regulation of these cytokines will allow us to understand their contribution in both disease and protection.
Gfi1 couples maturation of DP thymocytes and generation of nTreg cells (P4418)
Authors: Shi Lewis Zhichang , Kalupahana Nishan , Turnis Meghan , Neale Geoffrey , Vignali Dario , Chi Hongbo 
Published: January 2023

Abstract
Double-positive (DP) thymocytes respond to intrathymic TCR signaling by undergoing positive selection and lineage differentiation. Concomitant with these well-characterized events is the acquisition of mature T-cell gene-expression programs, notably the upregulation of effector molecules that are essential for their proper survival and trafficking, a process that is much less understood. nTreg cells also develop from immature thymocytes, but how their development is linked to the thymocyte maturation remains unclear. Here we report that Gfi1 has a central role in coupling DP cell maturation and thymic generation of nTreg cells. Using a conditional Gfi1 deletion system, we observed that specific ablation of Gfi1 in DP cells led to premature expression of mature effector genes and transcription factors, thereby facilitating developmental maturation. Associated with this “expedited” maturation of DP cells was expansion of nTreg cells. Mechanistically, we identified that elevated IL-2 signaling in the absence of Gfi1 drove the expansion of nTreg cells via a non-cell-autonomous mechanism. Finally, we provide evidence that deficiency of Gfi1 dampened anti-tumor immunity. Our results establish a Gfi1-dependent mechanism that actively maintains DP cell fate for proper developmental maturation and generation of nTreg cells.
Role of Dβ germline sequence on constraining TCR CDRβ3 diversity (P4426)
Authors: Levinson Michael , Silva Sanchez Aaron , Zhuang Yingxin , Schroeder Harry 
Published: January 2023

Abstract
Diversity of the T cell receptor is mainly developed through V(D)J rearrangement and N addition during TCR development. The product of V(D)J rearrangement is the CDRβ3, a region of high variability that recognizes antigen and includes all of the D gene. The Dβ sequence is highly conserved across various species, from trout to mouse to humans. This suggests that there are some natural constraints on the TCR; these constraints are thought to limit deleterious T cells from reaching the periphery. We hypothesize that altering the D region will have an effect on the development of thymocytes. To do this we have created Dβ altered mice. These mutants are a Dβ2 KO (Dβ1); a replacement of the Dβ locus with a charged Dβ (DβDKRQ); and a replacement of the Dβ locus with a hydrophobic DH (DβYTL). When compared to WT mice, the mutant Dβ mice have an altered T cell repertoire in both CDRβ3 amino acid composition and length and these differences can be attributed to the changes in the germline sequence. Changing the Dβ also changes the total T cell number in both developing and mature T cells, with a charged Dβ being selected against. Ongoing experiments will elucidate the role of the Dβ sequence on the development of T cells and the role it plays in infection and inflammation.
CD55 expression is induced during T cell maturation and protects recent thymic emigrants from complement-mediated killing (P4433)
Authors: Hsu Fan-Chi , Chen Meibo , McWilliams Douglas , Seaburg Lauren , Tangen Sarah , Shapiro Virginia 
Published: January 2023

Abstract
Newly generated T cells must undergo phenotypic and functional maturation. Previously, we showed that the absence of NKAP severely curtailed T cell maturation, and NKAP-deficient recent thymic emigrants (RTEs) fail to enter the long-lived naïve peripheral T cell pool. The paucity of peripheral T cells in CD4-cre NKAP conditional knockout (cKO) mouse is not due to apoptosis as neither loss of Bax nor Bcl-2 or Bcl-xL transgenes rescued the maturation defect. Here, we show that CD55, a complement regulatory protein functioning to disassemble C3 convertases, plays a role in T cell maturation. The expression of CD55, but not Crry or CD59, increases concurrently with T cell maturation by two orders of magnitude. NKAP-deficient peripheral T cells display a diminished expression of CD55 and an increase in complement C3 deposition, indicating CD55 is required for peripheral T cell fitness of RTEs. Reconstitution of CD4-cre NKAP cKO bone marrow into C3-deficient host partially rescues the maturation defect as measured by upregulation of Qa2 and CD55, and an increased proportion of mature naïve T cells. Thus, successful T cell maturation results in increased expression of CD55 that protects RTEs from complement-mediated killing.
The thymoproteasome subunit β5T generates pMHC specialized for positive selection of CD8 T cells (P4445)
Authors: Xing Yan , Hogquist Kristin 
Published: January 2023

Abstract
Recent data show that a thymoproteasome subunit β5T is uniquely expressed in cortical thymic epithelial cells (cTECs) and plays an essential role in the development of CD8 T cells. The thymoproteasome may generate peptides that are specialized for positive selection or it may simply serve to generate peptides that are distinct from other APCs that cause negative selection, thereby promoting an overall larger number of surviving clones to mature and function in the immune system. To distinguish these models, we engineered mice to express distinct peptide repertoires in cTECs versus other APCs, but not using β5T. We did this by generating β5t5i knock-in mice in which the immunoproteasome subunit-β5i replaced β5T in cTECs. When such animals were crossed to β5i-/- mice, β5i was exclusively expressed in cTECs, whereas β5 was expressed in other cells. However, this did not support normal positive selection, suggesting that β5T generates peptides that are intrinsically “better” for positive selection, and not merely because these peptides are distinct from peptides presented by other APC. Finally, using a Nur77GFP reporter, we demonstrate that the T cells generated in the absence of β5T have higher reactivity to self; generating predominantly CD44hi “memory phenotype” peripheral CD8+ T cells. Altogether our results suggest that the thymoproteasome supports positive selection by generating peptides that are optimized for the selection of weakly self-reactive, naïve T cell clones.
Genome-wide profiling of estrogen receptor alpha-bound chromatin in differentiating myeloid progenitors reveals regulation of inflammatory pathways by estradiol (P4470)
Authors: Kovats Susan , Turner Sean , Wren Jonathan , Dozmorov Mikhail 
Published: January 2023

Abstract
In inflammation, elevated GM-CSF directs the development of dendritic cells (DCs) from myeloid precursors that infiltrate tissues. These inflammatory DCs play a central role in infection and autoimmunity. We previously showed that estradiol and estrogen receptor alpha (ERα) act in murine Flt3+ myeloid progenitors to promote GM-CSF-mediated DC differentiation. ERs are ligand-dependent transcription factors that form complexes with chromatin-modifying coregulators near gene promoters. Thus, we hypothesized that ERα regulates chromatin structure at loci important for DC differentiation. We used anti-ERα chromatin immunoprecipitation and next generation sequencing to identify genome-wide sites of ERα binding in myeloid progenitors stimulated with GM-CSF -/+ estradiol. Bioinformatics analyses identified unique ERα binding sites in the presence of estradiol near the transcription start site of &gt;900 genes. Binding of ERα was enriched at CpG islands and consensus binding sites for SP1 and GABPA transcription factors. ERα bound to genes in pathways related to ER, GM-CSF and ERK/MAPK signaling, protein ubiquitination and cell cycle progression. ERα also bound to multiple genes in the NF-κB and Toll-like receptor pathways. These data suggest that ERα regulates genes involved in the NF-κB and GM-CSF signaling pathways during GM-CSF-mediated differentiation, and primes myeloid progenitors or mature DCs for responses to inflammatory stimuli.
Role of inhibins in dendritic cells differentiation and maturation (P4482)
Authors: Olguín Alor Roxana , Ambriz Peña Xochitl , Aleman-Muench Germán Rodrigo , Bonifaz Laura , Macías-Silva Marina , García-Zepeda Eduardo , Soldevila Gloria 
Published: January 2023

Abstract
Dendritic cells (DC) play a central role establishing the balance between tolerance and immunity. Inhibins and Activins, members of the TGFβ superfamily, have been implicated in the immune system as keys regulators of cellular functions, such as proliferation, apoptosis and differentiation. Several reports have previously shown the role of Activins in DC maturation and function, however the role of their closely related cytokines, the Inhibins, in those processes remains unclear. In this study, we compare the differentiation and maturation of bone marrow derived DC (BMDC) of wild type (WT) and Inhibin α deficient (KO) female mice. Our data showed that the percentage of immature BMDC was similar between WT and KO mice but, interestingly, analysis of mature BMDC obtained after lipopolysaccharide (LPS) stimulation (mBMDC) showed a significant reduction in the surface expression of MCHII, CD80 and CD86 in KO BMDC compared to WT mBMDC. In agreement, KO mBMDC retained the morphology characteristic of iDC, consisting in cellular spreading and presence of podosome like structures. Moreover, the chemotaxis of KO mBMDC towards CCL19 was significantly diminished in comparison to WT mBMDC. Collectively, these data show an impairment in the maturation of KO BMDC mediated by LPS, suggesting a role of Inhibins in the regulation of DC mediated functions. This data contribute to a better understanding of the mechanisms involved in DC maturation and the balance between tolerance and immunity.
Leucine rich repeat containing 8a is essential for lymphocyte development and function (P4372)
Authors: Kumar Lalit , Chou Janet , Yee Christina S.K. , Borzutzky Arturo , Vollmann Elisabeth , von Andrian Ulrich , Park Shin-Young , Hollander Georg , Manis John , Poliani P. Luigi , Geha Raif 
Published: January 2023

Abstract
LRRC8a encodes a ubiquitously expressed leucine rich repeat containing protein. Absence of B cells and agammaglobulinemia has been reported in a patient with a balanced translocation mutation affecting an LRRC8a allele. We have generated LRRC8a deficient mice in order to define the role of LRRC8a in B- and T-cells development and function. LRRC8a deficient mice exhibited a modest block in B cell development, decreased peripheral B cell numbers but intact intrinsic B cell function. In contrast, they exhibited a cell autonomous severe block in early thymic development with decreased proliferation and increased apoptosis of thymocytes, and severely impaired peripheral T cells function. The thymus had a ~ten-fold reduction in cellularity. TdT-mediated dUTP nick end labeling (TUNEL) staining demonstrated significantly increased numbers of apoptotic cells. LRRC8a deficient thymi had diminished content of phosphorylated Akt. LRRC8a constitutively associated with Grb2 and its ligation caused PI3-kinase dependent activation of Akt. These findings reveal a critical role for LRRC8a in the early development and peripheral expansion of B- and T-cells and in T-cell function.
Trp53 inactivation in the tumor microenvironment promotes tumor progression by enhancing MDSC differentiation (P2073)
Authors: Cui Yan , Guo Gang , Marrero Luis , Rodriguez Paulo , Ochoa Augusto 
Published: January 2023

Abstract
Inactivation of the tumor suppressor p53 is one of the leading causes of cancer as p53 inactivation via somatic mutations occurs in 50% of human cancers and sometimes in other cells of the tumor microenvironment (TME). Recent studies by our laboratory and others showed that innate and adaptive immunities are skewed towards pro-inflammation in hosts lacking p53 function. As chronic inflammation plays a vital role in tumor initiation, progression, and metastases, we hypothesized that p53 inactivation in the TME favors tumorigenesis by promoting inflammation. In this study, we compared the growth of subcutaneously inoculated B16F1 melanoma in p53null and WT mice. Tumor growth in p53null mice was greatly accelerated, correlating with marked increases in CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs), FoxP3+ regulatory T cells, and a loss of effector function, compared with those in WT mice. This augmented immunotolerance in tumor bearing p53null mice was associated with an enhanced MDSC proliferation, an increased frequency of myeloid progenitors in the peripheral lymphoid tissues, and a marked elevation of serum inflammatory cytokines/chemokines, compared with those of WT mice. Together, these results support our hypothesis and reveal a previously unappreciated function for p53 in maintaining an immunological microenvironment that suppresses tumor initiation and progression.
Thyroid status modulates the in vivo antitumor response to T lymphoma cells (P2079)
Authors: Sterle Helena A , Barreiro Arcos Maria L , Valli Eduardo , Paulazo Maria A , Colombo Lucas , Rabinovich Gabriel A , Cremaschi Graciela A 
Published: January 2023

Abstract
We have previously observed the regulation of immunity by thyroid status but little is known on how the levels of thyroid hormones (THs) influence antitumor responses. Our aim was to evaluate the antitumor immune response in hyper- and hypothyroid C57BL/6 mice (Hyper and Hypo respectively) which develop solid tumors and metastases in response to inoculation with EL-4 T lymphoma. Hyper showed increased rate of tumor growth compared to Hypo and control mice (C), while Hypo showed more metastases than other groups. Hyper Solid tumors had increased expression of cyclin D1, D3, E1, while Hypo had higher levels of cell cycle inhibitors p27, p16 and p53. At day 10th after EL-4 cell inoculation, when differences in tumor growth were significant, Hyper displayed higher number of cells in lymph nodes and spleens, a lower percentage (%) of myeloid-derived suppressor cells and an increased % of NK cells in the spleen accompanied by an augmented NK cell cytotoxic activity. On the other hand, Hypo displayed a reduction of CD8+ T cells and a decrease in tumor-specific cytotoxic activity. However, there were no differences among the groups in the % of T, B or Treg cells in secondary lymphoid organs. Our results suggest that THs modulate tumor growth through mechanisms involving regulation of proteins related to the progression and/or arrest of the cell cycle, and through the control of the anti-tumor immune response that could limit tumor dissemination.
FcγRIIB limits protection against F. tularensis LVS challenge induced by inactivated F. tularensis immunogen (P4294)
Authors: Franz Brian , Li Ying , Bitsaktsis Constantine , Iglesias Bibiana , Pham Giang , Rosa Sarah , Gosselin Edmund 
Published: January 2023

Abstract
We have previously shown that intranasal immunization with inactivated Francisella tularensis LVS targeted to FcR induces partial protection against a mucosal challenge with F. tularensis SchuS4 and that this protection is Ab and IFN-γ dependent. FcγRIIB, the only inhibitory FcγR, has been reported to regulate IgG production, which plays a major role in protection against F. tularensis LVS and SchuS4 challenge. Thus, we sought to determine the impact of FcγRIIB on immune protection against F. tularensis infection. We utilized inactivated F. tularensis as an immunogen. Naïve or inactivated F. tularensis-immunized FcγRIIB knockout versus wildtype C57BL/6 mice were challenged with varying doses of F. tularensis LVS. While we observed no difference in survival between naïve knockout versus wildtype mice, knockout mice immunized with inactivated F. tularensis showed significantly increased survival as compared to similarly immunized wildtype mice. Also, both F. tularensis-specific IgG and IgA production were elevated in serum and bronchoalveolar lavage fluid from inactivated F. tularensis-immunized knockout versus wildtype mice, as was IFN-γ production. In summary, our studies show that FcγRIIB limits the level of protection against F. tularensis challenge generated by inactivated F. tularensis immunization, by limiting the production of F. tularensis-specific IgG, IgA, and IFN-γ, which have been shown to be important for protection against F. tularensis infection.