bluuebunny/crossref_metadata_2025_split huggingface dataset:
AID phosphorylation is required for base excision repair during class switch recombination
Authors: Matthews Allysia J , Choi Jee Eun , Vuong Bao Q 
Published: January 2023

Abstract
Activation-induced cytidine deaminase (AID) generates dU:dG mismatches in the immunoglobulin heavy chain locus during class switch recombination (CSR). The resolution of these mismatches occurs primarily through the base excision repair (BER) pathway and additionally through the mismatch repair (MMR) pathway. The disruption of either pathway results in a reduction in class switch recombination, whereas ablation of both pathways completely blocks CSR. The phosphorylation of AID at Ser38 (pS38-AID) is required for wild-type levels of CSR, in part through its interaction with APE1, an essential component of the BER pathway. B cells carrying a homozygous knock-in mutation of the AID phosphorylation site (AIDS38A/S38A) have intermediate levels of CSR as compared to wild-type and AID−/− B cells. CSR in AIDS38A/S38AUNG−/− and AIDS38A/S38AMSH2−/− B cells is completely blocked. This data parallels the CSR defect observed in UNG−/−MSH2−/− B cells as compared to UNG−/− or MSH2−/− B cells and genetically confirms the critical role of pS38-AID in the BER repair pathway during CSR.
Inhibition of H3K27me3-specific demethylases promotes plasma cell formation
Authors: Kania Anna , Scharer Christopher , Boss Jeremy M 
Published: January 2023

Abstract
B cell terminal differentiation must be properly regulated to ensure robust humoral immune responses. In additional to the well-established role of key transcription factors, there is a growing interest in the epigenetic regulation of B cell differentiation. However, the epigenetic remodeling that occurs to suppress the B cell and promote the plasma cell fate is still poorly understood. Histone H3 lysine 27 trimethylation (H3K27me3) is a modification associated with a repressive chromatin state and gene silencing. H3K27me3 is established by EZH2 (component of PRC2) and was shown to be essential in the formation and maintenance of germinal centers. In addition, other studies have shown that active removal of silencing marks by H3K27me3-specific demethylases is necessary for T-cell differentiation. To further evaluate the role of H3K27me3 in plasma cell differentiation, we evaluated the effects of pharmacological inhibition of UTX and JMJD3 (H3K27me3-specific demethylases) in B cells stimulated ex vivo with LPS, IL2, and IL5 in the presence of the inhibitor or vehicle control. Our preliminary data suggest that retention of those silencing histone modifications nearly doubles the number of B220+ CD138+ plasma cells after 3-day ex vivo culture as assayed by flow cytometry. We also evaluated viability, gene expression profile, and functionality of the plasma cells treated with or without the inhibitor. Taken together, the collected data provide us with more insight into the role of H3K27me3 dynamics in B cell terminal differentiation.
Expression of immune checkpoint molecules on tumor infiltrating lymphocytes in glioblastoma multiforme
Authors: Park Junsik , Kwon Minsuk , Kim Kyung Hwan , Chang Jong He , Shin Eui-Cheol 
Published: January 2023

Abstract
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and is manifested with poor prognosis. GBM has long been recognized as an immunosuppressive neoplasm characterized by activation of various immune escape mechanisms. Recently, immune checkpoint inhibitors have shown clinically relevant improvements with high response rates and durable tumor remissions in several cancer types, and anti-PD-1, PD-L1 and CTLA-4 blockade are currently tested in clinical trials for GBM. However, the expression and principal role of the checkpoint molecules in GBM have not been well studied. The present study assessed the expression of immune checkpoint molecules in patients with GBM by flow cytometry. Overall levels of PD-1, CTLA-4, Tim-3 and LAG-3 on CD8+ T cells were significantly higher in tumor infiltrating lymphocytes (TILs) compared to those detected on the T cells in peripheral blood mononuclear cells (PBMCs). In the case of CD4+ TILs, PD-1, CTLA-4, Tim-3, LAG-3 and TIGIT were significantly increased. Furthermore, co-expression of the checkpoint molecules was prevalently found in TILs. PD-1+CTLA-4+, PD-1+Tim-3+, and PD-1+LAG-3+ CD8+ T cells and PD-1+CTLA-4+, PD-1+CTLA-4+Tim-3+, and PD-1+CTLA-4+TIGIT+ CD4+T cells were relatively enriched in TILs compared to PBMCs. However, in detail, checkpoint molecules in each individual patient showed various expression patterns. Collectively, our results indicate that GBM induces expression of multiple immune checkpoint molecules on TILs. Further studies are needed to determine whether immune checkpoint blockers can functionally restore these exhausted T cells and which combination of the blockers can optimally restore T cell function in GBM.
Depletion of Treg cells induces an increased activation of T-CD4+ and T-CD8+ cells during colorectal cancer
Authors: Terrazas Luis I , Olguín Efraín J , Medina-Andrade Itzel , Ledesma-Soto Yadira , Saavedra Rafael , Molina Emmanuel , Rodríguez-Sosa Miriam 
Published: January 2023

Abstract
Colorectal Cancer (CAC) is the second most commonly diagnosed cancer in women and the third in men in North America and Europe. CAC is associated with inflammatory responses where intestinal pathology is caused by a T-cell dysregulation that concludes in an imbalance between T activated (Tact) and T regulatory (Treg) cells. Treg cells are CD4+Foxp3+ cells that actively suppress pathological and physiological immune responses, contributing to the maintenance of immune homeostasis. It has been suggested a tumor-promoting function for Treg cells in CAC, but the kinetics of Treg cells during CAC development is poorly known. Thereby we used a mouse model of CAC induced by azoxymethane and three cycles of dextran sodium sulfate (DSS, 2%). We analyzed the percentage of Treg cells in blood, spleen and mesenteric lymph nodes (MLN) in each cycle. A significant reduction of Treg cells in blood and spleen during the first cycle, but increased percentage of Treg cells during the second and third cycle was observed. We did not observe reduction on Treg cells in the first DSS cycle in MLN, but a significant increase in percentage was detected during the second and third cycle of DSS. A Higher percentage of Treg cells-expressing PD1, CD127 and Tim-3 during the second and third DSS cycle in spleen and MLN was observed, whereas CD25 had no changes. However, we found increasing percentages of CD4+CD25+Foxp3− Tact cells only in the first DSS cycle in blood, spleen, and MLN. These results suggest that a gradually increased number of Treg cells suppress Tact cells during the second and third DSS cycle. Depletion of Treg cells with anti-CD25 PC61 antibody in the second DSS cycle increased percentages of CD4+CD25+Foxp3− Tact and TCD8+ cells, with an impact in tumorigenesis.
Separate molecular pathways mediate anti-tumor versus tumor-promoting aspects of Poly-I:C signaling in cancer microenvironments
Authors: Theodoraki Marie-Nicole , Sarkar Saumendra N , Mogundo Francesmary , Edwards Robert P , Kalinski Pawel 
Published: January 2023

Abstract

Background
We have previously shown that Poly-I:C, a frequently used adjuvant, induces both the CTL-attracting chemokines and Treg attractants. Here we evaluated the molecular pathways, which lead to the induction of chemokines by poly-I:C in TME and different types of tumor-associated cells, in order to develop improved adjuvants which selectively attract the desirable effector cells rather than suppressive cells.

Methods
Isolated cells or human cancer biopsies were cultured for 0.5–48 hours in the absence or presence of one of two synthetic TLR3 ligands Poly-I:C (non-selective activator of TLR3 and helicases) rintatolimod (selective TLR3 ligand), in the absence or presence of a COX-1/2 inhibitor, NF-kB- and TNFa inhibitors. mRNA assays, confocal microscopy, ELISA, chemotaxis assays and molecular biology assays were used to analyze the chemokine production and tumor-associated suppressive factors.

Results
We observed that poly-I:C induced activation of NF-kB- and COX-2 pathways leading to induction of COX2-dependent suppressive factors and Treg- and MDSC-attracting chemokines. These undesirable effects were blocked with inhibitors of both NF-kB- or COX-2 pathways. In contrast rintatolimod selectively induced the desirable chemokines, which were associated with lack of direct activation of NF-kB- or COX-2 pathways, and strongly suppressed attraction of Tregs and MDSCs, with elevated CTL attraction in ex vivo migration assays.

Conclusion
Our data implicates an important new role of helicases by the induction of tumor-promoting factors by dsRNA and points out to new targets to enhance the immunogenic and antitumor activities of adjuvants.
Th17 Cytokines Drive Liver Fibrosis Progression by Regulating TGF-β Signaling through Activation of MAPKs
Authors: Shoukry Naglaa H , Fabre Thomas , Molina Manuel Flores , Soucy Genevieve , Willems Bernard , Villeneuve Jean-Pierre , Bilodeau Marc 
Published: January 2023

Abstract
Activation of hepatic stellate cells (HSCs) is a key event in the initiation of liver fibrosis. We and others have demonstrated that IL-17A produced by Th17 cells promotes activation of HSCs. Th17 cells also produce IL-22, an enigmatic cytokine with pro-inflammatory and hepatoprotective properties. In addition, regulatory T cells (Treg) negatively modulate activation of HSCs. We hypothesized that liver fibrosis progression results from an alteration in the Th17/Treg ratio leading to an imbalance in pro-fibrotic Th17 cytokines in the liver. We examined ex vivo the frequency of Th17 and Treg populations and the cytokine profile of intrahepatic lymphocytes in liver biopsy samples (n=32). We observed increased Th17/Treg ratio in advanced as compared to moderate or no-fibrosis. Furthermore, we observed a bias towards Th17 cytokines in fibrotic livers with viral-hepatitis both in situ and ex vivo. All biopsies exhibited a 5-fold increase in IL-22 in fibrotic livers irrespective of aetiology. In vitro stimulation of HSCs with IL-22 sensitized them to suboptimal doses of TGF-β and activated p38 pathways. Chemical inhibition of p38 suppressed the pro-fibrogenic effect of IL-22. In vivo, lack of IL-22 signaling protected mice against liver fibrosis. IL-22RA1 Knockout mice exhibited reduced collagen deposition and expression of pro-fibrotic genes (ACTA2, LOXL2, TIMP-I, TGFb1, COL1A1) in comparison to wild-type littermates. Our results suggest a dysregulated Th17 response with increased IL-22 signaling in advanced fibrosis from all different aetiologies. Finally, we have identified IL-22 as a common factor in advanced liver fibrosis acting through sensitization of HSCs to TGF-β in a p38-dependent manner.
The use of tMUC1 highly specific chimeric antigen receptor-redirected T cells for the eradication of triple negative breast cancer
Authors: Zhou Ru , Roy Lopamudra Das , Yazdanifar Mahboubeh , Livasy Chad , Mukherjee Pinku 
Published: January 2023

Abstract
Antibody-derived Chimeric Antigen Receptor (CAR) T cells have great success in reduction of liquid form of tumor, but not solid tumor. Our novel antibody TAB 004 can specifically recognize the tumor form of MUC1 (tMUC1) while sparing the normal MUC1 in several subtypes of breast cancers including &gt;95% of triple negative breast cancer (TNBC). In vivo delivery of TAB 004 specifically accumulates in the xenograft TNBC tumor only. Therefore, we hypothesize that TNBC can be specifically targeted with TAB 004-derived tMUC1-specific CAR T cells. A panel of 45 human breast cancer cell lines were tested for tMUC1 level, and 11 out of 13 TNBC cell lines showed higher frequency of tMUC1 expression compared to that on normal cells. We engineered a 2nd generation human CAR using TAB 004 that was coupled to the CD28-CD3zeta. CAR was well expressed on activated human primary CD8 and CD4 T cells. Compared to their mock control, CAR-T cells expressed higher CD25 and CD11c, particularly on CD8 T cells. Those CAR-T cells specifically recognized the tMUC1 antigen and formed tight synapse with tMUC1high tumor cells in vitro. The susceptibility of TNBC cells to CAR-T cell cytolysis was dramatic while still corresponding to their tMUC1 level. Only the tMUC1-specific CAR-T cells expressed and released large amount of IFN-gamma after antigen recognition on TNBC cells. However, IFN-gamma was not directly involved in the tumor killing by CAR-T cells. The in vivo treatment of TNBC tumor by CAR-T cells is ongoing. Taken together, our TAB 004-originated CAR-T cells are very potent at killing TNBC tumor cells in a tMUC1-highly specific manner, which is very promising to provide a safe, effective and tumor antigen-specific immunotherapeutic intervention.
Targeted deletion of liver myeloid derived suppressor cells by inhibition of STAT3 dependent survival pathways to rescue CAR-T function
Authors: Gardell Jillian , Guha Prajna , Cunetta Marissa , Lima Matthew , Darpolor Josephine , Espat N. Joseph , Junghans Richard P. , Katz Steven C 
Published: January 2023

Abstract
Myeloid derived suppressor cells (MDSC) subvert anti-tumor immunity. Previously we reported that the GM-CSF/ JAK2/STAT3 axis drives liver MDSC (L-MDSC) proliferation and CAR-T suppression. We hypothesized that STAT3 supports L-MDSC survival and suppressive function by inhibiting apoptosis. We treated liver metastasis (LM) in mice with STAT3 inhibitors (STATTIC or BBI) or with vehicle control. STAT3 inhibition caused a significant reduction in tumor burden (p&lt;0.05) and L-MDSC frequency (DMSO 41±3% vs. STATTIC 29±3%/BBI 20±3%, p&lt;0.0001, n=10) in association with lower pSTAT3 levels (DMSO 33±4% vs. STATTIC 11±3%/BBI 9±2%, p&lt;0.0001, n=10). L-MDSC isolated from STATTIC or BBI treated mice were co-cultured with CAR-Ts and corresponding target tumor cells at 1:1:1 ratio. There was a significant decrease in tumor cell density (DMSO 100% vs. STATTIC 71±5%/BBI 20±3%, p&lt;0.05, n=5) and enhancement of tumor cell killing (DMSO 28±4% vs. STATTIC 54±4%/BBI 52±7%, p&lt;0.01, n=5). Rescue of CAR-T tumor killing function correlated with enhanced L-MDSC apoptosis signaling. We detected upregulation of pro-apoptotic proteins Bax, caspase 3, and Fas. Signaling molecules downstream of Fas, JNK and p38 MAPK (p&lt;0.05), were also activated in L-MDSC. In contrast, L-MDSC pro-survival Bcl2, pErk, and pAkt (p&lt;0.05) were downregulated in response to STAT3 inhibition. Microarray results confirmed the STAT3-induced changes in apoptotic and survival gene expression, which was validated by RT-PCR (p&lt;0.05). Within LM, STAT3 inhibition drove L-MDSC apoptosis via the Fas/Fas- L pathway with downstream pro-apoptotic signaling through p38 MAPK. Blocking STAT3 may have clinical application for enhancing immunotherapy for LM.
Active Specific Immunotherapy plus Doxorubicin Chemotherapy Mediates Durable Remission of Lethal Canine Hemangiosarcoma
Authors: Konduri Vanaja , Halpert Matthew M , Chen Yunyu , Liang Dan , Levitt Jonathan M , Neal Brittany , Husdon Caleb , Hottinger Heidi , Piscoya Sindy , Wilson Nicola , DiBernardi Lisa , Stallings Shonda , Omarbekov Zarkhyn , Seelhoff Lori , Ramirez Oscar , Yao Qizhi C , Bhardwaj Ratan D , Ravi Vinod , Douglass Laurel , Decker William K 
Published: January 2023

Abstract
Angiosarcoma is a deadly neoplasm of the vascular endothelium. Metastases are often present at diagnosis, and 5-year survival is only 10–30%. While the disease is uncommon in humans, angiosarcoma is a major killer of companion dogs, responsible for 120,000 deaths per year in the US. The canine disease (HSA) presents as acute hemoabdomen secondary to splenic rupture. Even if life-saving splenectomy is performed, median OS is only 48 days, and one-year survival is 0%. Here we report an interim analysis of a phase I multi-site, open-label trial of chemo-immunotherapy performed on consecutively-presenting splenectomized canines with verified HSA. Subjects received doxorubicin plus an autologous cell-therapy that generates durable CD8+ memory. Disease was monitored monthly by abdominal ultrasound, chest x-ray, and echocardiogram. At the time of this submission, median OS had not yet been reached in the per protocol population, with 75% of animals alive and healthy at up to one year post-splenectomy (p&lt;0.0002). Abdominal ultrasound documented resolution of local mesenteric disease in one animal, sternal lymphadenopathy in another, and hepatic metastases in a third. No significant adverse events were reported. Administration of this therapy appears feasible, safe, and highly efficacious in dogs. If subjects survived long enough to begin treatment, prognosis became highly favorable. The results suggest additional clinical studies in both canines and humans are warranted.
Cyclophosphamide preconditioning facilitates autoimmune vitiligo and enhanced antitumor efficacy following vaccination with activated dendritic cells.
Authors: Mullins David W , Alexander Matthew P 
Published: January 2023

Abstract
Cyclophosphamide (CTX) has been used as a lymphoablative conditioning agent to deplete regulatory T cells (Tregs) and enhance the efficacy of adoptive immune therapies. We initially investigated whether CTX conditioning could enhance the immunogenicity of melanoma Ag-pulsed dendritic cells (DC) in a murine model. CTX enhanced Ag-specific CD8+ T cell responses and control of SC-growing OVA+ melanoma following immunization with activated OVA257–265-pulsed DC; immunogenicity and tumor control were abrogated by reconstitution of Treg compartments. Unexpectedly, CTX-conditioned, DC-immunized animals developed significant vitiligo, despite the absence of exogenous melanocyte-specific Ag in the vaccine. CTX treatment or DC immunization alone failed to induce vitiligo. Injection of CTX-conditioned mice with MHC class II−/− DC, but not β2 microglobulin−/− DC, induced vitiligo regardless of exogenous Ag, suggesting that the induction of vitiligo may result from cross-presentation of endogenous melanocyte Ag in an environment of relaxed tolerance. Ab-mediated depletion of CD8 cells abrogated the vitiligo. These data suggest that CTX conditioning liberates class I-restricted melanocyte Ag for cross-presentation by activated DC to cognate CD8 cells, which in turn, achieve full activation and effector function in the absence of a normal regulatory environment. CTX conditioning may also open dermal compartments for increased effector T cell infiltration. Thus, CTX mediates multiple immunomodulatory mechanisms that may impact the future design of immunotherapy for melanoma.
Low-dose chemotherapy induces immunogenic tumor dormancy in mouse mammary carcinoma cells
Authors: Smith Timothy M , Butler Savannah E. , Wang Xiang-Yang Shawn , Manjili Masoud H 
Published: January 2023

Abstract
Patients with early stage cancer do not usually die from primary cancer, which tends to be responsive to therapy, but rather as a result of distant recurrence of the tumor in the form of advanced stage diseases. This phenomenon can be explained by cancer dormancy. However, many patients that harbor dormant tumor cells survive without experiencing recurrence. It has been suggested that certain chemotherapeutics that induce immunogenic tumor cell death (ICD) could prolong survival of patients because of inducing an anti-tumor immune response. However, tumor-reactive immune cells might fade away due to toxic doses of chemotherapy and/or tolerogenic properties of dormant tumor cells. Here, we hypothesize that some chemotherapeutic drugs at a low dose could also induce immunogenic tumor dormancy (ITD) for constant stimulation of the immune system. To test our hypothesis, we used neu overexpressing mouse mammary carcinoma (MMC) cells, and different doses of Adriamycin, Cyclophosphamide, or a combination therapy of 5-flurouracil, Adriamycin, and Cyclophosphamide (FAC). We demonstrated that low dose FAC was more effective in inducing ICD and ITD compared with other drugs or more cytotoxic doses. These findings warrant further examination into using a conditioning regimen of low-dose chemotherapeutics as a means of establishing ICD and ITD, thereby inducing and maintaining an immune response for the prevention of tumor recurrence.
Antibody-dependent Tumor Phagocytosis Enhances PD-L1 and IDOs Expression on Macrophages, Which Mediate Trastuzumab Resistance in Her2+ Breast Cancer
Authors: Song Erwei , Su Shicheng , Zhao Jinghua 
Published: January 2023

Abstract
The immune response has been linked to the therapeutic effect of trastuzumab, the monoclonal antibody against Her2. However, the underlying mechanism remains unclear. Here, we reported that the infiltration of tumor-associated macrophages is associated with the reduction of CD8+ T cells and NK cells in tumors and poor response of trastuzumab-containing neo-adjuvant chemotherapy in Her2+ breast cancer patients. In vitro, the macrophages suppress proliferation and tumoricidal effect of CD8+ T cells and NK cells after phagocytosis of Her2+ tumor cells mediated by trastuzumab in a CD16 and CD32a-dependent manner. By using global expression screening, we identified the immunosuppression effect is due to the upregulation of PD-L1 and IDOs on macrophages after tumor phagocytosis. Accordingly, optimal response of 4D5, the mouse anti-human Her2 antibody as trastuzumab parental drug, require macrophage depletion or anti-PD-L and IDO inhibition in tumor-bearing mice. In consistent with results form mice, the expression of PD-L1 and IDOs on tumor-associated macrophages increase in clinical samples of patients who received trastuzumab-containing neo-adjuvant chemotherapy, but not in those of patients who received neo-adjuvant chemotherapy without trastuzumab. Collectively, our data suggest that trastuzumab and double immune checkpoint blockade exert non-redundant clinical effects on Her2+ breast cancer patients with dense tumor-associated macrophages infiltration.
The antitumor function of anti-4-1BB therapy involves the suppression of CD73-A2BR axis
Authors: Chen Siqi , Fan Jie , Zhang Minghui , Qin Lei , Dominguez Donye , Long Alan W , Zhang Bin 
Published: January 2023

Abstract
Agonist antibodies (Ab) directed against costimulatory molecule CD137 (4-1BB) on the surface of antigen-primed T-lymphocytes are currently in various stages of pre-clinical and clinical trials, albeit with limited therapeutic benefit as single agents. Here, we examined the inhibitory role of ecto-enzyme CD73 (generating adenosine) on the antitumor efficacy of agonistic anti-4-1BB Ab therapy, as anti-4-1BB treatment can downregulate the expression of CD73 on T cells within tumor microenvironment. CD73-deificient mice treated with anti-4-1BB Ab completely rejected CD73-nonexpressing B16-SIY melanoma when compared to wild-type mice. To explore the therapeutic relevance of these observations, we combined anti-4-1BB and anti-CD73 Ab to treat mice with established B16-SIY melanoma. This combination therapy induced tumor regression associated with enhanced antitumor CD8+ T cell responses and reduced CD4+Foxp3+ regulatory T cell number and function. In contrast, neither anti-4-1BB nor anti-CD73 monotherapy is effective to control the growth of established melanoma. Notably, anti-4-1BB treatment was also able to downregulate specifically the expression of adenosine receptor A2BR. Moreover, anti-4-1BB treatment elicited potent antitumor effect in A2BR-deficient mice as that in CD-73-deficient hosts. Our study establishes a novel mechanistic link between the CD73-A2BR axis and 4-1BB engagement. Thus, the blockade of CD73-A2BR axis has potential implications for more effective clinical targeting of 4-1BB and possibly other costimulatory molecules.