bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumor cell IDO1 increases intratumoral immunosuppressive Tregs independent of enzyme activity
Authors: Zhai Lijie , Bell April , Qian Jun , Ladomersky Erik , Lauing Kristen L , Wainwright Derek A 
Published: January 2023

Abstract

Objective
Indoleamine 2, 3 dioxygenase 1 (IDO1) is a rate limiting enzyme that converts tryptophan (Trp) into kynurenine (Kyn). IDO1 knockdown in murine glioblastoma (GBM) cells suppresses intratumoral regulatory T cell (Treg) recruitment and increases survival, but unexpectedly, has no effect on intratumoral Trp levels. Moreover, while GBM cell IDO1 overexpression increases intratumoral Treg levels, treatment with a pharmacological IDO1 enzyme inhibitor fails to reverse this effect. These novel data led us to question whether GBM cell IDO1 recruits Tregs independent of enzyme activity, in vivo.

Methods
Ido1−/− mouse GBM cells reconstituted with wild-type or enzyme-null (H350A) murine Ido1 cDNA, and IDO1−/− human GBM cells were created. HPLC for Trp/Kyn levels, cell proliferation, cell viability, and splenic macrophage-GBM cell co-cultures, were studied in vitro. Syngeneic or humanized mice intracranially-engrafted with modified mouse or human GBM cells, respectively, were studied for the effect(s) on Treg accumulation and/or survival.

Results
As compared with IDO1 WT GBM cells, IDO1 H350A GBM cells show a significant decrease of Trp metabolism without affecting cell proliferation and viability. As compared with vector control GBM cells, co-culture for both IDO1 WT and H350A GBM cells induces greater numbers of mature macrophages. Independent of enzyme activity, GBM cell IDO1 expression increases intratumoral Tregs and decreases animal survival.

Conclusions
We created novel GBM models for elucidating the mechanism of metabolism-independent, IDO1-mediated intratumoral Treg accumulation. Given the majority of cancers with IDO1 expression, we suspect that our work may be generalizable to many types of malignancies.
Blockade of IDO/TDO downstream effectors restricts cancer immune suppression
Authors: Campesato Luis Felipe , Budhu Sadna , Tchaicha Jeremy , Jaiswal Abhinav , Gigoux Mathieu , Pourpe Stephane , Liu Cailian , Zamarin Dmitriy , Manfredi Mark G , McGovern Karen , Wolchok Jedd D , Merghoub Taha 
Published: January 2023

Abstract
Immune checkpoint blockade (ICB) results in clinical benefit for a subset of cancer patients, yet multiple mechanisms of resistance can impair optimal response. The catabolism of tryptophan into metabolites known as kynurenines (Kyn) by the expression of enzymes such as IDO or TDO is a frequent phenomenon that plays a suppressive role in tumor immunity. Recently it was shown that Kyn acts as agonist of the aryl hydrocarbon receptor (AHR). Here we sought to characterize the mechanisms of immune suppression associated with the AHR pathway and to evaluate its potential as therapeutic target. RNAseq analysis of human cancers revealed a correlation between the expressions of AHR-related genes with markers associated with immunotherapy resistance (PD-1, FOXP3, CD206). By using IDO or TDO-overexpressing variants of a melanoma cell model (B16-F10), we found that myeloid cells, such as tumor-associated macrophages (TAMs) and dendritic cells (DCs), present up-regulation of the AHR. IDO-expressing tumors (B16-IDO) show higher myeloid cell infiltration, which present a tolerogenic phenotype. Tumor-antigen specific CD8T cells present reduced expression of activation markers and proliferation rate when primed by Kyn-treated BMDCs. Treatment of B16-IDO-bearing mice with an AHR-specific antagonist (CH-223191) leads to an increase of MHC II in TAMs, of activation markers in CD8 T cells and reduced frequency of T-regs. AHR inhibition delays progression of tumors with an active IDO/TDO/Kyn pathway (B16-IDO and B16-TDO), and efficacy is further improved when ICB is used in combination. In summary, our findings demonstrate that targeting the Kyn pathway through AHR inhibition could overcome key suppressive mechanisms and sensitize tumors to ICB.
B Cell Subset Changes During Ovarian Cancer
Authors: Riggs James Edward , Maslanka Jeff , Londregan Jennifer , Goldman Naomi , DePierri Kelley , Somerville John 
Published: January 2023

Abstract
Early biomarkers of ovarian cancer (OvCa) are needed for timely disease detection. Monitoring alterations in the immune system might be informative in this regard. To study humoral immunity during OvCa, we transplant murine epithelial carcinoma cells (ID8) into the peritoneal cavity (PerC). As the PerC is enriched for B1 cells, we assessed B cell subset composition via flow cytometry. As OvCa developed PerC B1 cells were lost while B2 cells persisted in the PerC and spleen (SP). This difference might reflect that self-reactive B1 cells have a role in housekeeping and lack progenitors in adult mice. We tested the latter hypothesis by monitoring transitional (T) B cells, and found the T1, T2, and T3 subsets were markedly reduced in late stage disease, suggesting depletion of B1 B cells, as opposed to expansion of B2 B cells. Intriguingly, marginal zone B cells (MZB) expanded early then contracted as OvCa progressed. We speculate that housekeeping burden grows with OvCa progression and the cells most associated with this vital homeostatic process, notably B1 and MZB cells, are most at risk. These findings highlight the disruption of B cell biology in mice challenged with OvCa, and may help to inform strategies to develop biomarkers for the disease.
Potent anti-tumor effector functions in tumor-infiltrating MAIT and γδ T cells isolated from colon cancer patients
Authors: Rodin William Carl Ivar , Sundström Patrik , Ahlmanner Filip , Lindskog Elinor Bexe , Järbrink Marianne Quiding 
Published: January 2023

Abstract
In colon cancer, tumor progression and patient outcome is affected by the cytokine balance in the tumors. IFNγ, TNFα and Granzyme B expression are associated with favorable patient outcome, while high IL-17 expression is associated with accelerated tumor progression. However, knowledge of the regulation and activation of unconventional T cell subsets in colon tumors is limited. The aim of this study was to characterize unconventional T cells in colon tumors and unaffected tissue, determine their capacity to produce cytokines affecting tumor progression as well as the In vitro cytotoxic capabilities of MAIT and γδ T cells. Using flow cytometry, we show that MAIT cells accumulate in colon tumors and that the frequencies of γδ T cells are reduced in the tumor epithelium. Using polyclonal stimulation, we show that IFNγ production by tumour infiltrating MAIT cells is impaired whilst tumour infiltrating γδ T have an increased expression of IFNγ, TNFα and Granzyme B. IL-17 expression was also elevated in tumour infiltrating γδ T cells, but at lower levels than the TH1 - associated cytokines. Tumor infiltrating MAIT cells had an exhausted (PD-1highTim-3+) phenotype compared to MAIT cells from unaffected tissue. Analyzing cytokine expression, we show that while no single molecule is lost the polyfunctional capacity of tumour infiltrating MAIT cells is decreased compared to MAIT cells from unaffected tissue. Altogether, this study shows that γδ T cells and MAIT cells contribute to the cytokine balance in colon tumors with a TH1 – dominated profile and that they have potent cytotoxic capacity, which may reduce tumor progression and improve patient outcome.
Regulatory T cells suppress the cytotoxic phenotype of T cells in intestinal tumors of APCMin/+ mice
Authors: Szeponik Louis , Akeus Paulina , Järbrink Marianne Quiding , Rodin William Carl Ivar 
Published: January 2023

Abstract
The presence of activated T cells in colorectal cancer (CRC) tissues is a strong predictor of patient survival. Our previous research have shown that regulatory T cells (Treg) are able to reduce T-cell transendothelial migration in vitro and accumulation of effector T cells in intestinal tumors in vivo in a murine model for intestinal adenomas (APCMin/+).
In this study we investigated the effect of Treg depletion on the cytotoxic potential of conventional αβ T cells and γδ T cells in intestinal adenomas. We used the APCMin/+ \DEREG mouse model, which harbours a high affinity diphtheria toxin receptor under the control of the FOXP3 promoter, to deplete Treg in tumor bearing mice. We found that the number of CD8αβ T cells per mg tissue in the lamina propria was significantly increased in the Treg depleted intestinal adenomas in comparison to the non-depleted tumors. We could confirm this finding with IHC staining in tissue sections. The number of CD8αα T cells and γδ T cells remained unchanged. Furthermore, ex vivo frequencies in the lamina propria of Granzyme B+ CD8αβ T cells were increased in the Treg depleted intestinal adenomas. Following in vitro stimulation of lymphocytes from lamina propria with PMA/ionomycin, there was a trend towards a higher frequency of IFNγ+ CD8αβ T cells in Treg depleted adenomas, but frequencies of CD107a+ CD8αβ T cells were decreased. The frequency of TNF+CD8αβ T cells was elevated in the tumor in comparison to the unaffected tissue regardless of Treg depletion. We are investigating the combined effect of Treg depletion and PD-1 immunotherapy on the cytotoxic phenotype of T cells in the intestinal adenomas.
The results indicate that the modulation of Treg in colorectal cancer could have apositive effect on T cell cytotoxicity.
Tumor infiltrating B cells co-localize with CD4 T effector cells within organized tertiary lymphoid structures to present antigen and educate the anti-tumor immune response in human primary tumors
Authors: Bruno Tullia Carmela , Ruffin Ayana , Cillo Anthony , Liu Dongyuan , Kunning Sheryl , Ferris Robert L , Vignali Dario A.A. , Bruno Tullia Carmela 
Published: January 2023

Abstract
Only 20% of cancer patients produce a durable response to current immunotherapies. Thus, a need exists to develop additional therapeutic strategies to treat these patients, which includes evaluation of other tumor infiltrating immune cells that could further augment the T cell response. Tumor infiltrating B cells (TIL-B) represent a possible target for immunotherapy due to their crucial role in the immune response. In fact, current data demonstrate that detection of TIL-Bs within tertiary lymphoid structures (TLS) correlate with increased survival in patients with solid tumors and enhanced response to anti-PD1 immunotherapy. We hypothesize that TIL-Bs help generate potent, long-term immune responses against cancer by presenting tumor antigens to CD4 TILs within TLS.
We observed increased numbers of activated TIL-Bs in the primary tumors of head and neck squamous cell carcinoma and non-small cell lung cancer patients. We further assessed the transcriptional signature and location of TIL-Bs within the TME and demonstrated that they are adjacent to Th1 and Tfh CD4+ tumor infiltrating lymphocytes (TILs) within organized, germinal center containing TLS. Further, we generated an antigen presentation assay in vitro, and we observed increased CD4+ TIL responses when TIL-Bs presented autologous tumor antigens. These data suggest that TIL-Bs influence the function of CD4+ TILs in patient tumors within TLS. Ultimately, results from this study will increase effective targeting of TIL-Bs within patient primary tumors.
Altered phenotypes of tumor-infiltrating B cells in response to exhausted CD8+ T cells
Authors: Avalos Christian A , Egelston Colt , Simons Diana , Lim Min Hui , Huang Yinghui , Lee Peter P. 
Published: January 2023

Abstract
During chronic infections, such as cancer, tumor antigen presentation and inflammation mobilizes a heterogeneous T cell response, consisting of cells in unique states of differentiation and functional capacity. We assayed tumor-infiltrating lymphocytes from human breast, colorectal and melanoma tumors. By flow cytometry, we observed T cells undergoing exhaustion as characterized by a loss of effector functions (IFNy, TNFa, and IL-2) and expressing surface markers PD-1, TIM-3 and CD39. Although this cell intrinsic signature of T cell exhaustion has been well studied, its association with B lymphocytes is still obscure. CXCL13 expression was one of the most significantly upregulated genes in tumor exhausted T cells, as observed by single-cell sequencing. We identified infiltration of CD138+ CD38− plasma cells and CD138−CD38−CD19+ B cells in human breast, colorectal and melanoma tumors. In addition, we observed, by immunohistochemistry, large tertiary lymphoid structures (TLS) in human breast cancer tumors composed of CD20+ B cells and T cells in close proximity. Finally, we evaluated the differential expression of immune modulatory molecules GARP, CD39 and CD73 on B cell subsets from tumors. Further work will investigate the inhibitory or stimulatory role of B cells on tumor-infiltrating T cells.
The death receptor Fas mediates local bystander killing of antigen-negative variants by antigen-specific CD8 T cells in a heterogeneous tumor
Authors: Upadhyay Ranjan , Wroblewska Aleksandra , Baccarini Alessia , Brown Brian D , Brody Joshua D 
Published: January 2023

Abstract
Antigen-specificity is one of the hallmarks of the adaptive immune system, and CD8 T cells are particularly crucial for eliminating malignant cells with aberrant expression of tumor-associated self-antigens or neoantigens. We established a high-throughput pooled CRISPR/Cas9 screen for functionally assessing cancer cell genes involved in modulating the cytotoxic activity of antigen-specific CD8 T cells. As validation of our approach, we identified many genes known to be altered in cancers refractory to immunotherapy, including MHC component B2m and the checkpoint molecule Cd274. Interestingly, the cell surface death receptor Fas was identified as a strong hit in mediating the killing of antigen-positive lymphoma and was further verified with breast cancer, despite the availability of other cytotoxic effectors such as perforin/granzymes. Using a 2-antigen system, we surprisingly observed that Fas was also mediating the killing of neighboring GFP-negative cancer cells by T cells highly specific for a GFP epitope. This phenomenon was not dependent on MHC Class I expression but was potentiated by interferon gamma, which is known to upregulate Fas expression. Even for T cells that were previously primed, this bystander cytotoxicity required the presence of neighboring antigen-positive cells, suggesting a very hyperlocal and temporally regulated off-target effect that was not dependent on natural killer cells in vivo. We believe this phenomenon to be crucial to the durable remissions seen with highly antigen-specific approaches such as CAR-T cell therapy. Modulating this pathway may be a viable approach for preventing immune escape of rare antigen-loss variants or treating heterogeneous tumors with no clear single target antigen.
Characterizing unconventional T cells in the tumor microenvironment of metastatic osteosarcoma
Authors: Appel Nicole , Christie John , Blattman Joseph 
Published: January 2023

Abstract
Osteosarcoma is the most common bone cancer and typically affects patients in the second decade of life. Current treatment methods have not proven effective for treating reoccurring or metastatic osteosarcoma (mOS) given the 5-year survival rate of 15–30%. Previous work has shown anti-PD-L1 combined with anti-CTLA-4 improves survival of mOS in mice from 0% in no treatment mice to 60% in treated mice. To further improve survival, we analyzed tumor infiltrating lymphocytes (TILs) in mice over time and discovered CD4hiCD8hiPD-1hi T cells consistently appeared in the tumor microenvironment (TME) after approximately two months. To determine whether these CD4hiCD8hi, or double positive (DP) cells, were candidates for immune therapy, TILs from mice with long-term cancer were stained for CD3 to confirm T cell lineage, CD44 to verify activation, and Qa-2, which is first expressed during the stage IV single positive phase of T cell maturation and is therefore a marker to distinguish mature from immature T cells. The DP TILs were found to be activated, mature T cells that are distinct from DP immature thymocytes. The DP TILs were further compared to splenocytes and were determined to be concentrated in the TME rather than resulting from a systemic change in the immune system. Finally, the presence of DP T cells in the lungs was found to be unique to long-term lung metastases when lung tissues from age-matched healthy mice were obtained and processed alongside experimental lung metastases. Overall, mature and activated DP T cells concentrate in the TME of long-term lung metastases of mOS.
Identification of exhausted CD8+ T cells in low tumor mutation burden breast cancer patients
Authors: Egelston Colt , Avalos Christian A , Simons Diana , Huang Yinghui , Lim Min Hui , Lee Peter P. 
Published: January 2023

Abstract
Tumor immunogenicity is generally thought to be correlated with increased tumor mutation burden and the resulting neoantigen driven T cell reactivity to cancer cells. This immunogenicity results in the formation of tumor specific, but exhausted tumor infiltrating CD8+ T cells (TILex). Breast cancer tumors, which are predominantly low mutation burden, are widely viewed as non-immunogenic. Here we demonstrate that subsets of both triple negative and estrogen receptor positive breast cancer patients have primary tumors heavily infiltrated by tumor specific CD8+ TILex. CD8+ TILex in breast cancer patients were demonstrated to coexpress PD-1 and CD39 and showed a significant reduction of IFNγ, TNFα, and IL-2 production capacity. Like melanoma and colorectal CD8+ TILex, CD8+ TILex human breast tumors had increased expression of CD103, CD38, and TIM-3 in addition to loss of KLRG1 and CD127 expression. Similarly, melanoma, colorectal, and breast tumor CD8+ TILex shared transcriptional signatures identified by single cell sequencing. T cell receptor sequencing revealed a distinct repertoire of CD8+ TILex as compared to other CD8+ TILs from the same tumors, suggesting them to be a unique population in response to tumor antigen. Finally, we demonstrated that increased levels of CD8+ TILex in human breast tumors are not associated with higher levels of tumor mutation burden, as assessed by a tumor mutation load oncogene panel. This work suggests that a subset of breast cancer patients have inflamed, tumors associated with the presence of exhausted CD8+ T cells and that these patients may benefit from immunotherapeutic interventions.
Satb1 deficiency licenses TFH-differentiation
Authors: Chaurio Gonzalez Ricardo A , Biswas Subir , Payne Kyle K. , Galindo Carmen Maria Anadon , Costich Tara Lee , Perales-Puchalt Alfredo , Perez-Sanz Jairo , Harro Carly M , Mine Jessica A , Allegrezza Michael J , Svoronos Nikolaos , Kroeger Jodi , Robinson John , Conejo-Garcia Jose R 
Published: January 2023

Abstract
T Follicular Helper cells (TFH) provide both co-stimulation and stimulatory cytokines to B cells to facilitate affinity maturation, class switch recombination, and plasma cell differentiation within the germinal center. However, is not clear how TFH differentiation is regulated. We found that deficiency of the chromatin organizer Satb1 results in increased TFH formation in CD4Cre+Satb1flx/flx mice through up-regulation of the canonical TFH markers ICOS and PD-1 and suppression of Foxp3+PD-1highCXCR5+ T follicular regulatory (TFR) cells as well. Accordingly, CD4Cre+Satb1flx/flx mice, or RAG1−/− mice transferred with Satb1-deficient CD4+ T cells showed a dramatic accumulation of CD4+CXCR5+PD-1high upon ovarian tumor challenge, compared to their Satb1+ counterparts, which was associated with reduced tumor growth. Importantly, intratumoral administration of Satb1-deficient CD4+ T cells re-directed to target ovarian cancer cells through chimeric receptors, but not their Satb1+ counterparts, induce the formation of Tertiary Lymphoid Structures in most tumors.

Conclusion
Satb1 controls three mechanisms relevant for TFH differentiation and, subsequently, antigen-specific humoral responses; namely, PD- 1 expression, ICOS de-repression and TFR formation. Our results suggest a novel role for Satb1 as a major regulator of TFH differentiation and TLS during tumor formation.
Anti-alpha-enolase T cell response in oral squamous cell carcinoma
Authors: Chia Jean-San , Tuan Chih-Hsuan , Lay Fang-Yun , Ye Jung-Hsuan , Chiu Yen-Ling 
Published: January 2023

Abstract
In Taiwan, oral cancer ranks as the 6th highest incidence of cancer in general population. Characterized by high metastatic potency, oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. Alpha-enolase (α-enolase) is a glycolytic enzyme expressed in most tissues. Many researches have pointed out the over-expression of α-enolase in various cancer type. Its role as glycolytic enzyme and plasminogen receptor were reported to promote cancer invasion, proliferation, and metastasis.
Our works focused on the relationship between α-enolase and OSCC. We found the increased α-enolase expression in OSCC and were able to detect anti-α-enolase antibodies in serum of some OSCC patients. These results revealed a non-negligible influence of α-enolase in OSCC. Next, we spliced α-enolase from whole protein into peptide pool and tested T cell response upon its stimulation. Both CD8+ T cells and CD4+ T cells from peripheral blood mononuclear cells (PBMCs) and tumor infiltrating lymphocytes (TILs) were able to detect the cytokine production, like interferon gamma (IFN-γ) or tumor necrosis factor (TNF-α), and as well as the expression of activation marker like CD107a. Taken together, our works indicated that α-enolase is a potential antigen that may be involved in anti-tumor response in OSCC.
Metformin potentiates BCG efficacy against Mtb infection
Authors: Haugen Jessica , Obregon-Henao Andres , Ackart David , Todd Alexandra , Basaraba Randall 
Published: January 2023

Abstract
Tuberculosis (TB) is a chronic inflammatory disease that is caused by the bacterium Mycobacterium tuberculosis (Mtb) and is currently the leading cause of death by an infectious disease worldwide. Presently, TB therapeutic strategies include prolonged treatments with antimicrobial drugs, which often produce toxic side-effects, and vaccination with Bacille Calmette-Guérin (BCG), the only available and only partially protective TB vaccine. Considering the critical need for better prevention strategies, there have been multiple attempts to enhance the efficacy of BCG, yet none have significantly outperformed BCG alone. Previously, we have demonstrated that the anti-diabetic drug, metformin, has immunomodulatory effects and is associated with increased host resistance against TB. Based on our findings we hypothesized that following BCG vaccination, treatment with metformin would also enhance the vaccine response to Mtb. To test our hypothesis, we vaccinated guinea pigs with BCG Pasteur, dosed them with metformin or mock treatment, and performed low dose aerosol infection with Mtb H37Rv. At 90 days following infection, histological evaluation revealed that guinea pigs that received metformin- BCG had significantly reduced lung lesion burden compared to BCG alone. In addition, we evaluated the effects of metformin on T cell differentiation using an in vitro model of anti-CD3/anti-CD28 activation and found that metformin enhances memory T cell marker expression. Moreover, we show that mitochondrial hyperpolarization, a critical component of T cell activation, is dampened by metformin, which may ultimately alter T cell differentiation towards a memory-like phenotype and help explain metformin’s protective efficacy.