bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunological characterization of oncogene-driven models of hepatocellular carcinoma. (100.19)
Authors: Scarzello Anthony , Stauffer Jim , Back Tim , Subleski Jeff , Weiss Jonathan , Ortaldo John , Wiltrout Robert 
Published: January 2023

Abstract
Constitutively active AKT, MET, and beta-catenin (CAT) are initiating oncogenes that efficiently induce hepatic primary tumors when co-delivered; but not as single agents. Using a qPCR assay, we have begun to detail the early events of oncogene integration and to correlate the amount of integrated oncogene with developing tumor size. Furthermore, we found that the serum from mice injected with MET/CAT have elevated levels of alpha fetoprotein, a biomarker which has been similarly observed in advanced cases of HCC. Correlating the influx of infiltrating leukocytes and serum biomarker levels with the quantity of integrated oncogenes is critical to characterize their relative contributions to tumor progression. The profile of liver leukocytes in both MET/CAT and AKT/CAT murine models display phenotypes similar to those in HCC patients. By day 14, increased frequency and numbers of Tregs, MDSCs, as well as an up-regulation of PD-1 on CD4+ and CD8+ T cells was observed. The oncogene-driven tumor models described in this study exhibit many of the molecular and cellular events underlying HCC progression in humans. This molecularly defined approach to hepatocellular oncogenesis should enable us to characterize the contributions of inflammation in a primary tumor model with a defined oncogene signaling pathway.
Crystal structure of a gp100:44-59 peptide-HLA-DR4 complex enables design of an altered peptide ligand with enhanced immunogenicity (100.25)
Authors: Chen Shuming , Depontieu Florence , Li Yili , Salay Theresa , Mariuzza Roy , Topalian Suzanne 
Published: January 2023

Abstract
T cells recognizing tumor-associated self-antigens play a central role in anti-cancer immunity. CD4+ T cells are important in generating and regulating anti-tumor immunity, and MHC II-restricted tumor epitopes may enhance the clinical efficacy of polyvalent cancer vaccines. Gp100 is a non-mutated lineage-specific melanoma antigen containing the dominant HLA-DRB1*0401-restricted epitope gp100:44-59 with intermediate MHC binding affinity. The crystal structure of gp100:44-59 bound to HLA-DR4 was determined to 3 Å resolution to facilitate rational design of agonistic altered peptide ligands (APLs) which could improve the immunogenicity of this self antigen. The structure identified Leu48 as the peptide’s P1 MHC anchor, revealing suboptimal secondary anchors at P4, P7, and P9 based on published motifs. APLs with substituted secondary anchors were assessed for recognition by a gp100:44-59-specific CD4+ T cell clone, identifying P9 Q56A as an optimal APL with 10-fold enhanced T cell recognition. Fresh PBL from a DR4+ melanoma patient were twice stimulated in vitro with wild type (WT) or Q56A peptides and then assessed for peptide recognition (IFN-g ELISPOT). While WT-raised T cell cultures were non-specific, Q56A-raised cultures were specific for both Q56A and WT peptides. Q56A T cells also recognized DR4+, gp100+ melanoma cells (GM-CSF ELISA). These findings suggest that gp100:44-59 Q56A has improved immunogenicity and may warrant clinical testing as a melanoma vaccine.
Impaired tumoricidal activity in macrophages infiltrating intraocular tumors is caused by selective inhibition of inducible nitric oxide synthase (NOS2) (100.5)
Authors: Vicetti Miguel Rodolfo , Cherpes Thomas , McKenna Kyle 
Published: January 2023

Abstract
Transfer of ovalbumin (OVA) specific cytotoxic CD8+ T lymphocytes (OT-I CTL) into C57BL/6 mice produces rejection of OVA-expressing intradermal tumors in a NOS2-dependent manner, while intraocular OVA-expressing tumors are fully refractory to transfer therapy. We have previously found that infiltrating CTL were not suppressed in the ocular tumor microenvironment. However, macrophages (Mϕ) from CTL-transferred ocular tumors were not tumoricidal in vitro due to reduced NO production, despite high levels of NOS2 protein. We could replicate this phenomenon in vitro, when peritoneal and RAW264.7 Mϕ were stimulated with IFN-γ and TNF or LPS in the presence of aqueous humor (AqH). Moreover, we found decreased NOS2 enzymatic activity in lysates of these Mϕ, which was not due to increased Arg1 activity or inhibited GTP cylohydrolase activity since AqH did not affect their mRNA levels, and supplementation with L-arginine and tetrahydrobiopterin did not overcome AqH-mediated NO suppression. Interestingly, AqH did not affect the expression of NOS2, Arg1, CD40, PDL-1, MHC-II, IL-12 and TNF, indicating selective inhibition of NOS2 activity. Finally, TGF-β2, CGRP and α-MSH alone or in combination did not recapitulate the suppressive effect of AqH on NO production by Mϕ. In conclusion, reduced NO production by ocular tumor associated Mϕ was due to inhibition of NOS2 activity through a post-translational mechanism, suggesting that the ocular microenvironment can modulate Mϕ effector function.
A phosphorylated β-catenin peptide that is presented by HLA-A2 generates strong phosphospecific T cell responses against melanoma (101.10)
Authors: Obeng Rebecca , Le Poole I. , Hunt Donald , Engelhard Victor 
Published: January 2023

Abstract
Using metal ion affinity chromatography and mass spectrometry, we have previously shown that phosphorylated peptides are endogenously processed and presented by many different MHC I and II molecules, and have identified differentially displayed phosphopeptides presented by HLA-A2 on cancer cells. Many of the source proteins for these phosphopeptides are involved in tumorigenesis and metastasis. These peptides are appealing immunotherapeutic targets since mutations in or downregulation of the source proteins as a means of immune escape may compromise malignancy. We focused on one phosphopeptide spanning residues 30-39 of β-catenin (βcatpS33). When used to immunize HLA-A2 transgenic mice, βcatpS33 was very weakly immunogenic. Replacement of a suboptimal Ala anchor residue at P10 with a Val (βcatpS33(V)) enhanced the HLA-A2 binding affinity 10 fold and substantially improved immunogenicity. CD8 T cells from βcatpS33(V)-immunized mice were crossreactive to βcatpS33. The T cells also recognized endogenously processed βcatpS33 on several HLA-A2+ melanoma cells. Thus, crossreactivity to the natural βcatpS33 phosphopeptide can be maintained by making minimal changes in the sequence while preserving the ability of T cells to discriminate between the phosphorylated and unphosphorylated forms of the peptide. Enhancing immunogenicity by fine-tuning such an attractive tumor antigen linked to tumorigenic and metastatic processes should improve the efficiency of tumor control.
Mutations in BRCA-1 result in the functional loss of NKT cells (101.18)
Authors: Webb Tonya , Hester Danubia , Jones Laundette 
Published: January 2023

Abstract
Natural killer T (NKT) cells have been shown to be important in regulating immune responses to tumors; however, the number and function of NKT cells are reduced in cancer patients. Genetic factors regulating NKT cell number and function have yet to be determined. The Breast Cancer Susceptibility gene 1 (BRCA-1) encodes a tumor suppressor gene that functions, in part, as a caretaker gene in preserving chromosomal stability. In this study we have investigated the role of BRCA-1 on NKT expression and function using a transgenic mouse model in which BRCA-1 is mutated. This mouse model has a direct translational link to a specific type of human breast cancer, because it develops the same genetic changes that are described in BRCA-1-related human cancer. BRCA-1 is highly expressed in the T cell lineages, and we have found that our NKT cell lines express BRCA-1 protein. When we examined the liver and spleens of BRCA-1 mutant mice, we found that the NKT cell population was significantly reduced, compared to wildtype control mice. The classical CD4 and CD8 T cell subpopulations were comparable between the BRCA-1 mutant mice and wildtype controls, which suggests that NKT cell population is specifically regulated BRCA-1. Collectively, our data suggest that determining whether genetic susceptibility alters the function of NKT cells, a key regulator of anti-tumor immune responses, could help in designing novel therapeutics targeting aggressive breast cancers.
Toll-like receptor agonists to the rescue: saving tumor-specific T-cells (101.8)
Authors: Srivastava Ratika , Zheng Liquin , Geng Degui , Davila Eduardo 
Published: January 2023

Abstract
The molecular basis for the costimulatory effects of toll-like receptor (TLR) agonists are being gradually unravelled, adding to our understanding of how TLR signals enhance T-cell-mediated immune responses. Recent studies indicate that the adjuvant effects of certain TLR agonists may be attributed to activating TLR-myeloid differentiation factor (MyD88) directly in T-cells. We examined the survival of TLR2-MyD88-stimulated CD8 T-cells derived from melanoma patients and T-cell receptor transgenic pmel mice. TLR2 stimulation on pmel CD8 T-cells but not on TLR2-/-pmel or MyD88-/-pmel T-cells enhanced T-cell expansion primarily by reducing apoptosis rather than enhancing cell division. We determined the requirement for intrinsic MyD88 signals within pmel T-cells, by co-transferring congenic MyD88-/-pmel and pmel T-cells into CD45.1 mice and comparing T-cell numbers at different time points. Pmel T-cells outnumbered MyD88-/-pmel T-cells as early as 14 days after adoptive cell transfer and became more disparate after 34 days. MyD88-/- T-cells could not be rescued despite conditions sufficient to support pmel T-cell survival within the same environment. At the molecular level, we detected significant changes in various apoptotic molecules, favoring T-cell longevity. These findings reveal a novel role for TLR-MyD88 signals within tumor-specific T-cells which may inspire new approaches for enhancing cancer immunotherapies by manipulating TLR-MyD88 signaling within T-cells.
Identity of Toxoplasma gondii antigens that elicit CD4 T cells and their protective potential (130.13)
Authors: Satija Harshita , Blanchard Nicolas , Gonzalez Federico , Robey Ellen , Shastri Nilabh 
Published: January 2023

Abstract
Toxoplasma gondii (Toxo) can cause severe disease in immunocompromised individuals. Previous studies in various strains of mice have shown that genetic resistance to disease is linked to the MHC locus and protection is largely mediated by Toxo-specific CD8 T cells. In B10.D2 (H-2d) mice, CD8 T cells recognize an immunodominant peptide derived from the Toxo-protein, GRA6. However, a GRA6-specific response is not detected in C57BL/6 (B6, H-2b) mice. Instead, Toxo immunization of B6 mice elicits primarily a CD4 T cell response to unknown Toxo antigens. To identify the CD4 T cell stimulating antigens, we generated a Toxo-specific, lacZ inducible, CD4 T cell hybridoma and used it as a probe to screen a Toxo-cDNA library in bone marrow derived dendritic cells. The results reveal that CD4 T cells can be elicited by a hypothetical protein in the Toxo sequence database. We have defined the minimal peptide presented by MHC class II molecules and we will discuss the protective potential of this peptide-specific CD4 T cells in Toxo infected mice.
Retinoic acid and α-galactosylceramide differentially regulate CD19+ B cell activation in vitro and augment antibody production in vivo (130.20)
Authors: Chen Qiuyan , Ross A. Catharine 
Published: January 2023

Abstract
All-trans retinoic acid (RA) promotes the maturation and differentiation of B cells, which are known as a class of professional antigen-presenting cells. Here we have shown that CD1d, a MHC-class I-like molecule that presents lipid antigens, is expressed in the spleen mainly on B cells, and is increased by RA. Thus we hypothesized that RA and the CD1d ligand, α-galactosylceramide (αGalCer), could interact to promote the differentiation, maturation, and antibody response of antigen-activated B cells. αGalCer alone markedly stimulated and RA further increased B cell proliferation, synergizing with the B-cell antigen receptor. Combined treatment with RA and αGalCer also enriched a CD19hi B cell subpopulation, with higher CD1d expression, that exhibited a more differentiated phenotype in terms of sIgG1, CD138/syndecan-1 and PNA/Fas expression, as well as γ1 GLT, Pax-5, AID, and IRF-4, genes that control B cell proliferation and plasmacytic cell differentiation. In vivo, mice treated with RA and/or αGalCer during primary immunization with tetanus toxoid produced a higher anti-tetanus IgG response and, after reimmunization, had more bone marrow anti-tetanus antibody-secreting cells, indicative of heightened long-term memory. Thus, RA together with αGalCer can effectively regulate B cell proliferation and differentiation, ultimately promoting a more efficient antibody response to protein antigen.
Editing the pMHCI repertoire in the ER by tapasin and ERAAP (130.24)
Authors: Kanaseki Takayuki , Camfiled Lind Kristin , Shastri Nilabh 
Published: January 2023

Abstract
The peptide/MHC class I complexes (pMHCI) displayed on the cell surface are essential for eliciting CD8+ T cell responses for adaptive immunity. How appropriate pMHCI are assembled within the peptide loading complex (PLC) in the endoplasmic reticulum (ER) is unclear. Here we show that tapasin, the core component of the PLC, edits the pMHCI repertoire in vivo. Compared to cells from wild-type mice, cells from tapasin-deficient mice express an immunologically distinct pMHCI repertoire. Tapasin-deficient cells lack many normal pMHCI and also express a set of novel pMHCI on the surface. Thus, CD8+ T cells responses are elicited in reciprocal immunizations between wild-type and tapasin-deficient mice. Interestingly, this set of pMHCI ligands is distinct from that found earlier in mice lacking ERAAP, the ER aminopeptidase associated with antigen processing. Taken together these findings suggest that the pMHC I repertore is edited independently by tapasin and ERAAP in the ER.
The Contribution of Peptide-MHC Stability to Immunodominance and the Duration of Cross-Priming (130.31)
Authors: Watson Alan , Thompson Megan , Mylin Lawrence , Schell Todd 
Published: January 2023

Abstract
CD8+ T-cell responses are often multivalent, directed toward epitopes contained in one or several proteins. The response to Simian virus 40 large-tumor (T) antigen is directed toward four H-2b restricted epitopes (designated sites I, II/III, IV and V). Site V is immunorecessive since specific T cells are not detected following immunization unless the three dominant epitopes are inactivated in T antigen. Site V was previously shown to form unstable peptide-MHC (pMHC) complexes and to be inefficiently cross-presented. In this study, we identified point mutations within site V that increase the stability of pMHC while conserving recognition by site V-specific T cells. These mutations overcame the immunorecessive nature of site V within the context of full length T antigen. Increased immunogenicity of the site V variants was associated with an increase in both the proportion of naïve T cells that were primed and the duration of cross-priming in-vivo. We are currently investigating the contribution of the increased duration of epitope V cross-priming toward more effective naïve T cell recruitment. A model is proposed in which immunization approaches that extend the duration of cross-priming may promote effective T cell responses against otherwise weak epitopes.
Administration of a vaccine composed of dendritic cells pulsed with premalignant oral lesion lysate results in an increase in CD4+ and CD8+ T cells and a decrease in Foxp3+ cells in tongues of mice bearing carcinogen-induced premalignant oral lesions. (131.24)
Authors: Clark Anna-Maria , Young M. Rita 
Published: January 2023

Abstract
Most studies with dendritic cell vaccines have focused on eliminating or preventing progression of established malignancies. This is complicated by the immune suppression often exhibited in the presence of solid carcinomas. The goal of this study is to determine if an immune response can be elicited by administering a DC vaccine during the premalignant stages of oral squamous cell carcinoma, prior to development of systemic immune suppression. Mice treated with the carcinogen 4NQO in drinking water develop premalignant oral lesions which progress to OSCC. As previous studies in our lab demonstrated that premalignant lesions and OSCC overexpress common tumor antigens, BM-derived DCs were pulsed with premalignant lesion lysate and administered to 4NQO-treated C57/BL6 mice exhibiting premalignant lesions. Immunohistochemical analysis demonstrated an increase in CD8+ and CD4+ cells, as well as a decrease in Foxp3+ cells, in the tongues of 4NQO-treated mice immunized with premalignant lesion-pulsed dendritic cells (DCpm) compared to 4NQO-treated control mice. In addition, splenocytes from 4NQO-treated DCpm mice released greater amounts of IFN-γ compared to splenocytes from 4NQO-treated control mice in response to stimulation with antigen. These studies indicate that DCpm vaccination may be able to elicit a stimulatory immune response in 4NQO-treated mice bearing premalignant lesions.
Accumulation of a unique mature B cell population in aged mice. (132.2)
Authors: Hao Yi , O’Neill Patrick , Cancro Michael 
Published: January 2023

Abstract
Humoral immune responses and protective immunity are compromised in aged individuals, but the basis for this remains unclear. We have discovered a novel CD21/35-CD23-CD43-AA4.1-CD19+B220+ B cell population that gradually increases with age, expanding more than 5-fold in magnitude by 22 months of age. Despite sharing phenotypic features with mature follicular and marginal zone B cells, this novel subset is largely unresponsive to BCR, TLR or CD40 mediated stimulation. In addition, this population is markedly less reliant on the survival factor BLyS both in vitro and in vivo. The expansion of this unusual population does not reflect intrinsic features of cells derived from aged BM progenitors, but instead appears to be derived from a very small subset of FO B cells after exhaustive expansion. Together these findings reveal that primary B cell pools in aged individuals are increasingly populated by a unique population with the characteristics of “exhausted” B cells.
CD38 modulates CXCR4-mediated signals and homing of chronic lymphocytic leukemia (CLL) cells. (133.5)
Authors: Vaisitti Tiziana , Aydin Semra , Rossi Davide , Cottino Francesca , Audrito Valentina , Serra Sara , D'Arena Giovanni , Brennan Paul , Pepper Chris , Gaidano Gianluca , Malavasi Fabio , Deaglio Silvia 
Published: January 2023

Abstract
Human CD38 is a glycoprotein endowed with enzymatic and receptorial functions. Its engagement leads to activation/proliferation signals in T, B, NK and dendritic cells. In chronic lymphocytic leukemia (CLL) cells, CD38 drives proliferation and survival signals and its expression defines a subset of cells with higher migration and signaling ability in response to CXCL12, a critical chemokine in the re-circulation of leukemic cells from blood to lymphoid organs. The aim of this work is to define the role of CD38 in the regulation of CLL cell homing, an essential step in the maintenance and progression of the disease. Results indicate that i) CD38 signals stabilize early (ERK1/2 phosphorylation) and late (chemotaxis) functional responses to CXCL12. ii) The use of CLL clones with bimodal CD38 expression confirmed that the migrating population is CD38+. Furthermore, iii) de novo expression of CD38 using a lentiviral technique is followed by increased sensitivity to CXCL12 and ultimately chemotaxis. iv) In CLL cells, CD38 and CXCR4 are part of the same supra-molecular complex, that also includes the tetraspanin CD81 and the integrin CD49d. These results indicate that CD38 synergizes with the CXCR4 signaling pathway, through a specific molecular organization on CLL cells. The functional and physical association between CD38 and CXCR4 represents a novel mechanism in the regulation of neoplastic lymphocyte chemotaxis and homing and potentially a novel therapeutic target.
Role of CCR9-CCL25 axis in Prostate Cancer Metastasis (133.7)
Authors: Singh Shailesh , Sharma Praveen , Singh Rajesh , Grizzle William 
Published: January 2023

Abstract
Bone metastasis is major cause of prostate cancer (PCa) associated deaths and handful options are available to deal with this condition. Therefore, better understating of metastatic process and identification of molecular signature on metastatic cells are urgently needed to improve therapeutic. We have shown that chemokine receptor CCR9 is highly expressed by the PCa tissue and cells and play an important role in cell migration and invasion under the chemotactic gradient of CCL25, which is the only natural ligand for CCR9. CCL25 is primarily expressed by the thymus, which involutes with age. For the first time we show higher serum CCL25 in PCa patients in comparison to normal healthy donors and secretion of CCL25 within the primary prostate cancer in a paracrine manner. Interestingly, CCL25 was highly produced by the bone marrow cells of tumor bearing mice in comparison to non-tumor bearing mice. Furthermore, inhibition of CCR9-CCL25 interaction in vivo showed significant inhibition of bone metastasis and tumor establishment. These results provide clinical and biological significance of CCR9-CCL25 axis in prostate cancer metastasis. Higher production of CCL25 by the bone marrow cells of the tumor bearing mice confirms that CCL25 produced the bone marrow stromal cells are induced by the factors produced by the tumor cell to facilitate metastasis to the bone. Therefore, developing CCR9 directed therapies, may improve the therapeutic outcome of prostate cancer.
IL-16 Mediates CD4 T Lymphocyte Accumulation in the lymph nodes by desensitizing S1P1 (134.1)
Authors: Green Daniel , Richmond Jillian , Harstine Bo , Center David , Cruikshank William 
Published: January 2023

Abstract
IL-16 is a cytokine generated at sites of inflammation. Originally characterized as a CD4 ligand that induces migration, it is now known that IL-16 can alter TCR-induced cell activation and inhibit many chemokine receptors via cross-receptor desensitization. Previous work has demonstrated that stimulation by HIV-1 gp120 results in greater CCL21 induced migration with concomitant inhibition of sphingosine-1-phosphate (S1P) induced migration. Injection of gp120 into SCIDhu mice resulted in sequestration of CD4+ T cells within lymph nodes. We now investigated whether a natural ligand for CD4, IL-16, could similarly affect T cell homing. We found that IL-16 could not augment CCL21; however, was capable of inhibiting S1P induced migration. This effect was dependent on p56lck signaling and did not affect S1P receptor expression. IL-16 intratracheal instillation resulted in initial recruitment of CD4+ cells into the lung with subsequent recruitment into lung draining lymph nodes. Instillation of eotaxin-2 resulted in lung accumulation but not lymph node accumulation of T cells. The effect by IL-16 was CD4 dependent as no accumulation was seen using CD4-/- mice. Accumulation within the nodes occurred 2 h post instillation and resolved by 24 h. We propose that this is the first description of cytokine desensitization of S1P stimulation and further, suggests an additional mechanism by which IL-16 can regulate recruitment of cells and mediate the inflammatory process.