bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-4 PROTECTS THE CH31 B-CELL LINE FROM ANTI-IgM-INDUCED GROWTH ARREST AND APOPTOSIS: CONTRIBUTION OF THE PI-3′ KINASE/AKT PATHWAY (84.11)
Authors: Carey Gregory B. , Semenova Elena , Qi Xiulan , Keegan Achsah D. 
Published: January 2023

Abstract
Interleukin-4 (IL-4) promotes lymphocyte survival and protects primary lymphomas from apoptosis. Previous studies reported differential requirements for the STAT6 and IRS2/PI-3′ kinase signaling pathways in mediating the IL-4-induced protection from Fas-mediated apoptosis. In this study, we characterized IL-4-activated signals that suppress anti-IgM-mediated apoptosis and growth arrest of CH31, a model B-cell lymphoma line. In these cells, anti-IgM treatment led to mitochondrial dysfunction and the loss of activation-specific phosphorylation of Akt and of CDK2. These were followed by caspase activation, loss of BAD phosphorylation, growth-arrest and then apoptosis. Strikingly, IL-4 treatment prevented or reversed these changes, dramatically rescuing the cells from Go/G1-arrest and driving them back into S- and G2/M- phases of the cell cycle. Furthermore, IL-4 suppressed the activation of caspases 9 and 3 and, in contrast to previous reports, induced the phosphorylation (deactivation) of BAD. IL-4 treatment also induced expression of BclxL, a STAT6-dependent gene. Finally, pharmacologic inhibitors of PI-3′ kinase, of Akt and of JAK/STAT signaling and dominant inhibitory forms of PI-3′ kinase and Akt, abrogated IL-4 anti-apoptotic function. These results suggest that the IL-4 receptor activates several signaling pathways that act to suppress the apoptotic program activated by anti-IgM.
B Cell Receptor Crosstalk: The IL-4-induced Alternate Pathway for BCR Signaling Operates in Parallel with the Classical Pathway, Is Sensitive to Rottlerin, and Depends on Lyn (86.14)
Authors: Guo Benchang , Blair Derek , Chiles Thomas , Lowell Clifford , Rothstein Thomas 
Published: January 2023

Abstract
B cell exposure to IL-4 alters subsequent B cell receptor signaling such that ERK phosphorylation becomes signalosome-independent; however, the nature of this new, alternate signaling pathway and its relationship to the classical, signalosome-dependent signaling pathway, are not known. Here we report that the alternate and classical pathways for BCR signaling are differentially affected by rottlerin, and by Go6976 or LY294002, respectively. Further, in B cells lacking PKCâ, the classical pathway for BCR signaling is blocked, whereas the alternate pathway is little affected. Conversely, in B cells lacking Lyn, the alternate pathway for BCR signaling is blocked, whereas the classical pathway is little affected. The rottlerin-sensitive element is not PKCä, inasmuch as the alternate pathway as not blocked in PKCä-deficient B cells. These results indicate that the rottlerin-sensitive, Lyn-dependent alternate pathway, and the classical pathway, for BCR signaling operate in parallel when BCR engagement follows IL-4 exposure.
B-Cell-Receptor Signal-Transduction in Antigen Internalization and Presentation (86.15)
Authors: Malhotra Shikha , Cogeshall K Mark 
Published: January 2023

Abstract
Humoral immune response is initiated by triggering B cell receptor (BCR). Antigen-induced clustering of the BCR results in the assembly of a multimolecular signaling complex. We are investigating the link between antigen receptor-triggered signal transduction and receptor internalization in mouse B- lymphocytes. BCR internalization requires formation of clathrin-coated pits and actin polymerization. The dynamin GTPase provides energy for clathrin-mediated endocytosis of various receptors. We found that transfection of B cells with a GTPase defective Dynamin mutant prevents BCR internalization. Additionally, dynamin co-localized with the BCR during BCR internalization. Vav is a guanine nucleotide exchange factor for Rho GTPases (regulators of actin polymerization). We found Vav is similarly co-localized with the BCR, and transfection with inhibitory Vav mutants block activation of Rac and prevent BCR internalization. We propose a model in which Vav regulates the activity of Rac during BCR internalization. Once Rac is activated, actin nucleation proteins cause F-actin assembly, which is required for both BCR internalization and BCR movement to endosomal compartments where the antigen is processed and finally presented to a T cell. Studies are in progress to see if dynamin regulates Vav recruitment to the BCR, or if they are independently regulated molecules, but both are required for internalization.
Expression of bone specific alkaline phosphatase on human B cells (86.18)
Authors: Hossain Ashfaque , Jung Larry K 
Published: January 2023

Abstract
A complex relationship exists among the molecules involved in the development of the immune system and of the bony skeleton. Molecules involved in one system can exert effects on the other system. Alkaline phosphatase (AP) is produced at high levels by osteoblasts and it plays an important role in bone remodeling. AP activity is also found on human B cells although the exact nature is not clearly understood. The purpose of this study is to determine the nature of expression of AP in human lymphocytes. Using a monoclonal antibody against bone specific alkaline phosphatase (BAP), its expression was detected in approximately 50% of circulating B cells but not T cells. These cells were distinct from the circulating osteoblasts. Lymphocyte stimulation by TPA with or without ionomycin, did not change BAP expression. Using RT-PCR, BAP specific transcripts were detected in the B cells expressing surface BAP but not in those not expressing BAP. The expression of BAP on B cells was similar in children as in adults. Its expression on transformed B cell lines was variable and EBV-transformed B cells did not express BAP. BAP was predominantly expressed in the CD27negative subpopulation. As CD27 is thought to be a marker for memory lymphocytes, it might be inferred that BAP is down-regulated in the memory B cells. Collectively, these data suggest that BAP may play an important role in the differentiation and maturation of human B cells.
Negative Regulation of CD40-mediated B Cell Responses by E3 Ubiquitin Ligase Cbl-b (87.21)
Authors: Zhang Jian , Qiao Guilin , Lei Minxiang , Li Zhenping 
Published: January 2023

Abstract
CD40 is a TNF receptor (TNFR) superfamily member which is essential for B cell function. Cbl-b, an adapter protein and ubiquitin ligase, has been shown to regulate activation of T and B cells through their antigen receptors. In this study, we report that CD40-induced proliferation is significantly augmented in mice lacking Cbl-b. Furthermore, Cbl-b−/− mice display enhanced thymus–dependent (TD) Ab responses and germinal center (GC) formation, whereas introduction of CD40 deficiency abolishes the hyper-Ab responses and heightened GC formation in response to TD Ag challenge. Mechanistically, Cbl-b selectively down-modulates CD40-induced activation of NF-κB and JNK. Cbl-b associates with TNFR-associated factor 2 (TRAF-2) upon CD40 ligation, and inhibits the recruitment of TRAF-2 to the CD40. Together, our data suggest that Cbl-b attenuates CD40-mediated NF-κB and JNK activation, thereby suppressing B cell responses.
Role of IFN-γ and IL-12 in Silencing the IL-4-Producing Potential in Th1 Cells (87.29)
Authors: Zhuang Yonghua , Huang Zan , Nishida Jun , Masuda Jennifer , Gapin Laurent , Brown Melissa , Zhang Lin , Huang Hua 
Published: January 2023

Abstract
To develop into committed Th1 cells, naive CD4+ T cells not only need to acquire the capacity to produce IFN-γ, but also need to silence the IL-4-producing potential. The role of IFN-γ is thought to primarily upregulate the IL-12β2 chain expression and thus enhances the IL-12 responsiveness. The direct effect of IFN-γ in Th1 cell development remains less clear. Furthermore, it is not clear whether both the IFN-γ and the IL-12 pathway are critical in silencing the IL-4-producing potential in Th1 cells. In this study, we investigated the role of the IFN-γ and the IL-12 pathways in silencing the IL-4-producing potential in Th1 cells. We found that IFN-γ was essential in silencing the IL-4-producing potential in Th1 cells, while IL-12 only partially suppressed the IL-4-producing potential. IL-12 completely depended on STAT4, while IFN-γ completely depended on STAT1 to suppress the IL-4-producing potential. Interestingly, T-bet is only partially required for IFN-γ to silence the IL-4-producing potential, whereas it is absolutely required for IL-12 to suppress the IL-4-producing potential. Our study clarifies the role of IFNγ-STAT1-T-bet and IL-12-STAT4-T-bet pathway in silencing the IL-4-protential during Th1 cell development, indicating that an additional factor, whose induction is STAT1 signaling, may be critical in Th1 cell commitment.
This work is funded by an NIH grant (RO1 AI48568).
Monomeric Agonist pMHC Ligand Triggers TCR Signaling Independent of Endogenous Ligand (87.31)
Authors: Ma Zhengyu , Sharp Kim A , Janmey Paul A , Finkel Terri H 
Published: January 2023

Abstract
At the contact interface between T-cell and antigen presenting cell (APC), peptide antigen presented by MHC (pMHC) binds to T-cell receptor (TCR) and initiates signaling. The mechanism of TCR signal initiation, or triggering, remains unclear. A critical yet controversial issue is whether monomeric agonist pMHC is sufficient to trigger TCR, or if simultaneous engagement of TCRs by two pMHCs is required. Here, we show that CD4+ T-cells are triggered by very low numbers of monomeric agonist pMHCs anchored on fluid planar lipid bilayers. T-cells responded to bilayer-anchored agonist MCC-IEk in a sub-linear fashion, further indicating the sufficiency of monovalent ligand. Moreover, on bilayers, fixed plastic surfaces, or live APCs, endogenous pMHC did not enhance TCR triggering by agonist pMHC. Therefore, agonist pMHCs trigger TCR as individual monomers, independent of endogenous pMHC, supporting a model of TCR triggering by conformational change or kinetic segregation, and not via pMHC pseudodimers.
Wound repair mediated by γδ T cells requires mTOR (87.43)
Authors: Jameson Julie Marie , Mills Robyn Elaine 
Published: January 2023

Abstract
γδ TCR-expressing lymphocytes in the skin play roles in biological processes such as wound repair, tissue homeostasis, and tumor rejection.
γδ T cells regulate their epithelial neighbors by producing growth factors for keratinocyte proliferation, epithelial homeostasis, and inflammatory cell migration. Rapamycin is a triene macrolide, which inhibits mTOR signaling by binding FKBP12, thus inhibiting αβ T lymphocyte function. Rapamycin is approved by the U.S. Food and Drug Administration for the prophylaxis of acute kidney rejection, however patients that receive rapamycin report an increased incidence of wound healing complications. We hypothesize that rapamycin not only targets allograft-specific αβ T lymphocytes, but also suppresses skin γδ T cells. mTOR plays key roles in growth factor and cytokine signal reception, therefore rapamycin administration may mimic nutrient insufficiency. Our preliminary studies indicate that rapamycin arrests skin γδ T cell proliferation in G1 phase and causes them to undergo autophagy. We have established skin organ cultures to administer rapamycin to wounded murine skin. Our results demonstrate that when rapamycin is present, there is a defect in wound closure over time. We propose that rapamycin blocks skin γδ T cells from receiving survival signals, which results in the inhibition of skin γδ T cell proliferation and function negatively impacting wound repair.
Support from Leukemia and Lymphoma Society and NIH DK073098.
Adoptively transferred tumor-specific T cells expanded ex vivo using HSV amplicons encoding 4-1BBL persist in the host and demonstrate anti-tumor activity in vivo. (88.11)
Authors: Yi Kyung Hee , Nechushtan Hovav , Zhang Yu , Bowers William J , Tolba Khaled A , Podack Eckhard R , Federoff Howard J , Rosenblatt Joseph D 
Published: January 2023

Abstract
4-1BB is a T cell costimulatory receptor which promotes T cell expansion and survival. We studied the anti-tumor effects of adoptively transferred tumor-specific T cells expanded ex vivo using herpes simplex virus (HSV) amplicons encoding either 4-1BBL (HSV.4-1BBL) or B7.1 (HSV.B7). Lewis Lung Carcinoma cells expressing ovalbumin (LLC/OVA) were transduced with HSV.4-1BBL, HSV.B7, or control HSV and used to stimulate GFP+ OVA-specific CD8+ T cells (OT-1). Naïve or ex vivo-stimulated OT-1 were then transferred into LLC/OVA-bearing mice. Mice given 4-1BBL-stimulated OT-1 had significantly decreased tumor volumes compared to untreated mice (P&lt;0.0001) or mice given naïve OT-1 (P=0.0003). Transfer of B7-stimulated OT-1 did not control tumor growth. Higher percentages of OT-1 were seen in the blood, draining lymph nodes, and tumor for the 4-1BBL-stimulated OT-1 group compared to other groups at 8 days post transfer. BrdU incorporation of 4-1BBL-stimulated OT-1 was markedly increased within the tumor bed. Splenocytes from the 4-1BBL-stimulated OT-1 group showed increased cytolytic activity against LLC/OVA and higher numbers of OT-1 cells, which expressed CD44 and the memory marker Ly-6C, compared to controls. Tumor-specific T cells stimulated ex vivo using tumor transduced with HSV.4-1BBL expand efficiently in vivo resulting in tumor eradication and the generation of tumor-specific memory T cells.
Costimulation Through ICAM-1 Induces Differentiation of Human Naïve CD4+ T Cells to Regulatory T Cells (88.32)
Authors: Cool Kelli M , Dotson Abby L. , Otto Amber R. , Kohlmeier Jacob E. , Benedict Stephen H 
Published: January 2023

Abstract
Inducible regulatory T cells can be generated from precursor cells in the periphery. However, the specific precursors and the mechanism of Treg differentiation are not well characterized. We investigated the participation of Intercellular Adhesion Molecule-1 (ICAM-1) in the process of Treg induction beginning with human naïve CD4+ T cells, defined as CD45RA+CD45RO-CD11aloCD27+CCR7+. Costimulation of naïve CD4+ T cells through ICAM-1 (but not CD28) resulted in the appearance of a sizeable population of Foxp3+CD25+CD4+ Treg cells. This stimulation treatment also generated substantial quantities of the immunosuppressive cytokine IL-10. The Treg cells that differentiated following costimulation through ICAM-1 strongly inhibited responder cell proliferation in co-culture experiments. The ability of naïve CD4+ T cells to undergo this differentiation process was examined using cells from both young individuals and older individuals. These results indicate that ICAM-1 resident on the surface of naïve CD4+ T cells can mediate the differentiation of Tregs from naïve cells and suggest that ICAM-1 may be a signaling molecule to target for Treg therapies.
HVEM-BTLA interactions regulate early CD8+ T cell response against Listeria monocytogenes (88.33)
Authors: Sun Yonglian , Ruddy Matthew , Miller Mendy , Wang Yang , Lee Youjin , Kaye Jonathan , Murphy Kenneth , Pfeffer Klaus , Fu Yang-Xin 
Published: January 2023

Abstract
Negative regulation of T cell responses at the early phase of an immune response is largely unknown. Here, we show that the newly discovered co-inhibitory interaction between B and T lymphocyte attenuator (BTLA) receptor and herpesvirus entry mediator (HVEM) ligand is essential and sufficient to negatively regulate the early CD8+ T cell response against Listeria monocytogenes infection. BTLA expression is transiently up-regulated on bacteria-specific CD8+ T cells shortly after infection. Both HVEM−/− and BTLA−/−, but not LIGHT−/− mice, demonstrate resistance to Listeria infection. Accordingly, blocking BTLA pathway by antagonist anti-BTLA monoclonal antibody promotes antigen-specific CD8+ T cell expansion and IFN-γ production as well as bacteria clearance in vivo. In contrast, engagement of BTLA inhibitory signal with HVEM-Ig inhibited antigen-specific CD8+ T cell responses as well as bacteria clearance in a CD8+ T cell dependent manner, indicating the critical role of CD8+ T cell in early bacteria clearance and that cross-linking BTLA is sufficient to suppress CD8+ T cell response at an early stage. These studies reveal that HVEM-BTLA co-inhibitory interactions play a critical regulatory role in the early stages of the CD8+ T cell response against bacteria infection.
IL-15 administration to human CD4+ T cells leads to expansion of CD4+CD25− cells but to a decrease of CD4+CD25highFoxp3+T cells via apoptosis (88.44)
Authors: Strauss Laura , Bergmann Christoph , Whiteside Theresa L. 
Published: January 2023

Abstract
Objective: Adoptive transfer of CD4+CD25highFoxp3+ regulatory T cells (nTreg) for immune therapy will require the development of strategies to expand these cells on a clinical scale. We have shown that rapamycin promotes the survival of nTreg. IL-15 protects human T cells from apoptosis. However, effects of IL-15 on nTreg remain unknown.
Methods: CD4+CD25+ and CD4+CD25− T cells were sorted from PBMC of normal controls using AutoMACS. All separated T cells were expanded in the presence of anti-CD3/CD28 Abs, 1000 IU/mL IL-2 or 20 IU/mL IL-15 for 21 d. Rapamycin (1 nM) was added to half of the cultures. After 21 d sensitivity to apoptosis (AnnexV+) was determined. Regulatory function was tested by co-culture analysis with CFSE-labeled responders.
Results: TCR-stimulated CD4+CD25− T cells were sensitive to rapamycin-induced apoptosis, whereas Treg were resistant (90±7.5% vs. 12±10.5%). IL-15 + activated CD4+CD25− T cells were resistant to apoptosis relative to activated CD4+CD25− T cells alone (2±1.5 %). In contrast, Treg + IL-15 and rapamycin became sensitive to apoptosis (98±2.5% vs. 2.8±1.7%). Rapamycin enhanced the suppressor function of Treg (p ≤ 0.001). CD4+CD25− T cells were not suppressive, but expanded with IL-15 + rapamycin did suppress T cell proliferation (60±15%).
Conclusion: Our results indicate that proliferation and survival of Treg and T responders are mediated by different molecular pathways.
ROLE OF TLR4 TYROSINE PHOSPHORYLATION IN SIGNAL TRANSDUCTION AND ENDOTOXIN TOLERANCE (89.2)
Authors: Medvedev Andrei , Piao Wenji , Rhee Sang Hoon , Chen Haiyan , Basu Subhendu , Wahl Larry M , Fenton Matthew J , Vogel Stefanie N 
Published: January 2023

Abstract
This study examined if tyrosine phosphorylation of TLR4 is required for signaling. Introduction of the P712H mutation into the TIR domain of constitutively-active mouse ΔTLR4 and mutation of the homologous P714 in human CD4-TLR4 rendered them signaling-incompetent and blocked TLR4 tyrosine phosphorylation. Y674A and Y680A mutations within the TIR domains of CD4-TLR4 impaired its ability to elicit phosphorylation of p38 and JNK, IκB-α degradation, and activation of NF-κB and RANTES reporters. Full-length human TLR4 expressing Y674A or Y680A mutations showed suppressed LPS-inducible cell activation that correlated with altered MyD88-TLR4 interactions, increased association with a short IRAK-1 isoform, and decreased levels of activated IRAK-1 in complex with TLR4. Pretreatment of HEK293/TLR4/MD-2 cells with protein tyrosine kinase or Src kinase inhibitors suppressed LPS-driven TLR4 tyrosine phosphorylation, p38 and NF-κB activation. Induction of endotoxin tolerance markedly suppressed LPS-mediated TLR4 tyrosine phosphorylation and recruitment of Lyn kinase to TLR4, but did not affect TLR4-MD-2 interactions. These data demonstrate that TLR4 tyrosine phosphorylation is important for signaling and is impaired in endotoxin tolerance, and suggest involvement of Lyn kinase in these processes.
This study was supported by NIH grants AI-059524 (AEM), AI-057490 and AI-44936 (SNV).
HMGB1 secretion is regulated by protein kinase C (89.26)
Authors: Oh Young Joo , Youn Ju Ho , Shin Jeon Soo 
Published: January 2023

Abstract
High mobility group box-1 protein (HMGB1) is secreted from activated monocytes/macrophages and known as a key late mediator of sepsis, so the regulation of secretion is important to control the sepsis. Phosphorylation of HMGB1 is one of major secretion pathways in our previous report. To investigate the phosphorylation-related pathway of HMGB1, LPS-induced HMGB1 secretion was observed with various inhibitors in RAW264.7 cells. Wortmannin and LY294002 inhibited HMGB1 secretion, suggesting the involvement of phosphoinositide 3-kinase (PI3K). Akt inhibitor IV and rapamycin failed to inhibit HMGB1 secretion, suggesting no relevance of Akt-mTOR axis pathway. In contrast, protein kinase C (PKC) inhibitor Gö6983 could inhibit HMGB1 secretion. And we confirmed that HMGB1 was directly phosphorylated by PKC but not by casein kinase II or cdc2 in in vitro kinase assay using autoradiography and □-scintillation counting. When RAW264.6 cells were pre-treated with JNK inhibitor, LPS-induced HMGB1 secretion was decreased but not by PD 98059 and SB 203580, p42/44 and p38 pathway inhibitors respectively. These results suggesting that PKC is effector kinase for HMGB1 phosphorylation for secretion and PI3K may act in concert to control of HMGB1 secretion via a pathway independent manner of p42/44 and p38 MAPK. Which specific isoform of PKC is involved in HMGB1 phosphorylation is now under investigation.
TYROSINE PHOSPHORYLATION OF MAL IS ESSENTIAL FOR SIGNAL TRANSDUCTION AND IS BLOCKED IN ENDOTOXIN TOLERANCE (89.8)
Authors: Piao Wenji , Fitzgerald Katherine A. , Medvedev Andrei E. 
Published: January 2023

Abstract
Posttranslational modifications of TLRs, adapter proteins and IRAKs are important in signalosome assembly. This study examined the role of tyrosine phosphorylation for signal-transducing functions of MAL, and analyzed if induction of endotoxin tolerance inhibits LPS-induced MAL tyrosine phosphorylation. Overexpression of wild-type MAL in 293T cells led to its constitutive tyrosine phosphorylation and activation of p38 MAPK, IκB-α degradation, and IL-8 mRNA expression. In contrast, tyrosine-deficient Y86A, Y106A, and Y159A MALs showed impaired abilities to signal upon overexpression in 293T cells, and exerted dominant-negative effects on LPS-driven NF-κB reporter activation in HEK293/TLR4/MD-2 cells. Mutations of the Y187, Y195, and Y196 did not affect MAL signaling and did not confer upon it the ability to act as a dominant-negative inhibitor of LPS signaling. LPS stimulation of HEK293/TLR4/MD-2 cells and human monocytes resulted in tyrosine phosphorylation of endogenous MAL, which was significantly impaired in LPS-tolerant cells. LPS-inducible association between endogenous MAL and Bruton’s tyrosine kinase (Btk) was observed in cell extracts obtained from medium-pretreated human monocytes, whereas LPS failed to induce Btk recruitment to MAL in endotoxin-tolerant cells. Thus, phosphorylation of MAL is required for TLR signaling, and is inhibited in endotoxin tolerance.
This work was supported by NIH grant AI-059524 (to A.E.M.)