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Browsing by Author "Lee, Kelvin P."
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Item CD8+ T cell metabolic flexibility elicited by CD28-ARS2 axis-driven alternative splicing of PKM supports antitumor immunity(Springer Nature, 2024) Holling, G. Aaron; Chavel, Colin A.; Sharda, Anand P.; Lieberman, Mackenzie M.; James, Caitlin M.; Lightman, Shivana M.; Tong, Jason H.; Qiao, Guanxi; Emmons, Tiffany R.; Giridharan, Thejaswini; Hou, Shengqi; Intlekofer, Andrew M.; Higashi, Richard M.; Fan, Teresa W. M.; Lane, Andrew N.; Eng, Kevin H.; Segal, Brahm H.; Repasky, Elizabeth A.; Lee, Kelvin P.; Olejniczak, Scott H.; Medicine, School of MedicineMetabolic flexibility has emerged as a critical determinant of CD8+ T-cell antitumor activity, yet the mechanisms driving the metabolic flexibility of T cells have not been determined. In this study, we investigated the influence of the nuclear cap-binding complex (CBC) adaptor protein ARS2 on mature T cells. In doing so, we discovered a novel signaling axis that endows activated CD8+ T cells with flexibility of glucose catabolism. ARS2 upregulation driven by CD28 signaling reinforced splicing factor recruitment to pre-mRNAs and affected approximately one-third of T-cell activation-induced alternative splicing events. Among these effects, the CD28-ARS2 axis suppressed the expression of the M1 isoform of pyruvate kinase in favor of PKM2, a key determinant of CD8+ T-cell glucose utilization, interferon gamma production, and antitumor effector function. Importantly, PKM alternative splicing occurred independently of CD28-driven PI3K pathway activation, revealing a novel means by which costimulation reprograms glucose metabolism in CD8+ T cells.Item Indoleamine 2,3-dioxygenase 1 is essential for sustaining durable antibody responses(Elsevier, 2021) Lightman, Shivana M.; Peresie, Jennifer L.; Carlson, Louise M.; Holling, G. Aaron; Honikel, Mackenzie M.; Chavel, Colin A.; Nemeth, Michael J.; Olejniczak, Scott H.; Lee, Kelvin P.; Medicine, School of MedicineHumoral immunity is essential for protection against pathogens, emphasized by the prevention of 2-3 million deaths worldwide annually by childhood immunizations. Long-term protective immunity is dependent on the continual production of neutralizing antibodies by the subset of long-lived plasma cells (LLPCs). LLPCs are not intrinsically long-lived, but require interaction with LLPC niche stromal cells for survival. However, it remains unclear which and how these interactions sustain LLPC survival and long-term humoral immunity. We now have found that the immunosuppressive enzyme indoleamine 2,3- dioxygenase 1 (IDO1) is required to sustain antibody responses and LLPC survival. Activation of IDO1 occurs upon the engagement of CD80/CD86 on the niche dendritic cells by CD28 on LLPC. Kynurenine, the product of IDO1 catabolism, activates the aryl hydrocarbon receptor in LLPC, reinforcing CD28 expression and survival signaling. These findings expand the immune function of IDO1 and uncover a novel pathway for sustaining LLPC survival and humoral immunity.Item Intron-Retention Neoantigen Load Predicts Favorable Prognosis in Pancreatic Cancer(American Society of Clinical Oncology, 2022) Dong, Chuanpeng; Reiter, Jill L.; Dong, Edward; Wang, Yue; Lee, Kelvin P.; Lu, Xiongbin; Liu, Yunlong; BioHealth Informatics, School of Informatics and ComputingPurpose: High tumor mutation burden (TMB) in many cancer types is associated with the production of tumor-specific neoantigens, a favorable outcome and response to immune checkpoint blockade (ICB) therapy. Besides mutation-derived neoantigens, aberrant intron retention also produces tumor neopeptides that could trigger an immune response. The relationship between intron-retention-derived tumor neoantigens (IR-neoAg) and clinical outcomes in pancreatic cancer remains uncertain. Here, we quantify IR-neoAg in pancreatic cancer and evaluate whether IR-neoAg load might serve as a biomarker for selecting patients who may benefit from ICB therapy. Methods: We developed a computational approach to estimate patient-specific IR-neoAg load from transcriptome data available in The Cancer Genome Atlas pancreatic cancer cohort. Associations between IR-neoAg load and patient overall survival were evaluated using Kaplan-Meier estimates and Cox regression. Differential expression of immune checkpoint and HLA-I genes was evaluated in tumors with high IR-neoAg load. Results: High IR-neoAg load predicted better overall survival in pancreatic cancer, although no association was found for TMB. IR-neoAg load remained a significant prognostic factor after adjusting for patient age, sex, tumor stage and grade, and TMB. Moreover, pancreatic tumors with both high IR-neoAg load and high HLA-I gene expression had similar gene expression profiles as other tumor types that showed response to anti-programmed cell death protein 1 therapy. Conclusion: IR-neoAg load is associated with favorable survival in pancreatic cancer. These findings provide strong evidence for considering IR-neoAgs when selecting patients who might benefit from ICB therapy.Item Leadership Diversity and Development in the Nation's Cancer Centers(Oxford University Press, 2022) Lerman, Caryn; Hughes-Halbert, Chanita; Falcone, Mary; Gosky, David M.; Jensen, Roy A.; Lee, Kelvin P.; Mitchell, Edith; Odunsi, Kunle; Pegher, Jennifer W.; Rodriguez, Elisa; Sanchez, Yolanda; Shaw, Reuben; Weiner, George; Willman, Cheryl L.; Medicine, School of MedicineThe capacity and diversity of the oncology leadership workforce has not kept pace with the emerging needs of our increasingly complex cancer centers and the spectrum of challenges our institutions face in reducing the cancer burden in diverse catchment areas. Recognizing the importance of a diverse workforce to reduce cancer inequities, the Association of American Cancer Institutes conducted a survey of its 103 cancer centers to examine diversity in leadership roles from research program leaders to cancer center directors. A total of 82 (80%) centers responded, including 64 National Cancer Institute-designated and 18 emerging centers. Among these 82 respondents, non-Hispanic White individuals comprised 79% of center directors, 82% of deputy directors, 72% of associate directors, and 72% of program leaders. Women are underrepresented in all leadership roles (ranging from 16% for center directors to 45% for associate directors). Although the limited gender, ethnic, and racial diversity of center directors and perhaps deputy directors is less surprising, the demographics of current research program leaders and associate directors exposes a substantial lack of diversity in the traditional cancer center senior leadership pipeline. Sole reliance on the cohort of current center leaders and leadership pipeline is unlikely to produce the diversity in cancer center leadership needed to facilitate the ability of those centers to address the needs of the diverse populations they serve. Informed by these data, this commentary describes some best practices to build a pipeline of emerging leaders who are representative of the diverse populations served by these institutions and who are well positioned to succeed.Item Mitigating the prevalence and function of myeloid-derived suppressor cells by redirecting myeloid differentiation using a novel immune modulator(BMJ, 2022) Oliver, Liliana; Alvarez, Rydell; Diaz, Raquel; Valdés, Anet; Colligan, Sean H.; Nemeth, Michael J.; Twum, Danielle Y. F.; Fernández, Audry; Fernández-Medina, Olivia; Carlson, Louise M.; Yu, Han; Eng, Kevin H.; Hensen, Mary L.; Rábade-Chediak, Maura L.; Fernández, Luis Enrique; Lee, Kelvin P.; Perez, Leslie; Muhitch, Jason B.; Mesa, Circe; Abrams, Scott I.; Medicine, School of MedicineBackground: Immune suppression is common in neoplasia and a major driver is tumor-induced myeloid dysfunction. Yet, overcoming such myeloid cell defects remains an untapped strategy to reverse suppression and improve host defense. Exposure of bone marrow progenitors to heightened levels of myeloid growth factors in cancer or following certain systemic treatments promote abnormal myelopoiesis characterized by the production of myeloid-derived suppressor cells (MDSCs) and a deficiency in antigen-presenting cell function. We previously showed that a novel immune modulator, termed 'very small size particle' (VSSP), attenuates MDSC function in tumor-bearing mice, which was accompanied by an increase in dendritic cells (DCs) suggesting that VSSP exhibits myeloid differentiating properties. Therefore, here, we addressed two unresolved aspects of the mechanism of action of this unique immunomodulatory agent: (1) does VSSP alter myelopoiesis in the bone marrow to redirect MDSC differentiation toward a monocyte/macrophage or DC fate? and (2) does VSSP mitigate the frequency and suppressive function of human tumor-induced MDSCs? Methods: To address the first question, we first used a murine model of granulocyte-colony stimulating factor-driven emergency myelopoiesis following chemotherapy-induced myeloablation, which skews myeloid output toward MDSCs, especially the polymorphonuclear (PMN)-MDSC subset. Following VSSP treatment, progenitors and their myeloid progeny were analyzed by immunophenotyping and MDSC function was evaluated by suppression assays. To strengthen rigor, we validated our findings in tumor-bearing mouse models. To address the second question, we conducted a clinical trial in patients with metastatic renal cell carcinoma, wherein 15 patients were treated with VSSP. Endpoints in this study included safety and impact on PMN-MDSC frequency and function. Results: We demonstrated that VSSP diminished PMN-MDSCs by shunting granulocyte-monocyte progenitor differentiation toward monocytes/macrophages and DCs with heightened expression of the myeloid-dependent transcription factors interferon regulatory factor-8 and PU.1. This skewing was at the expense of expansion of granulocytic progenitors and rendered the remaining MDSCs less suppressive. Importantly, these effects were also demonstrated in a clinical setting wherein VSSP monotherapy significantly reduced circulating PMN-MDSCs, and their suppressive function. Conclusions: Altogether, these data revealed VSSP as a novel regulator of myeloid biology that mitigates MDSCs in cancer patients and reinstates a more normal myeloid phenotype that potentially favors immune activation over immune suppression.Item PDZ proteins SCRIB and DLG1 regulate myeloma cell surface CD86 expression, growth, and survival(American Association for Cancer Research, 2022) Moser-Katz, Tyler; Gavile, Catherine M.; Barwick, Benjamin G.; Lee, Kelvin P.; Boise, Lawrence H.; Medicine, School of MedicineDespite advances in the treatment of multiple myeloma in the past decades, the disease remains incurable, and understanding signals and molecules that can control myeloma growth and survival are important for the development of novel therapeutic strategies. One such molecule, CD86, regulates multiple myeloma cell survival via its interaction with CD28 and signaling through its cytoplasmic tail. Although the CD86 cytoplasmic tail has been shown to be involved in drug resistance and can induce molecular changes in multiple myeloma cells, its function has been largely unexplored. Here, we show that CD86 cytoplasmic tail has a role in trafficking CD86 to the cell surface. This is due in part to a PDZ-binding motif at its C-terminus which is important for proper trafficking from the Golgi apparatus. BioID analysis revealed 10 PDZ domain-containing proteins proximal to CD86 cytoplasmic tail in myeloma cells. Among them, we found the planar cell polarity proteins, SCRIB and DLG1, are important for proper CD86 surface expression and the growth and survival of myeloma cells. These findings indicate a mechanism by which myeloma cells confer cellular survival and drug resistance and indicate a possible motif to target for therapeutic gain.Item Role of Sphingolipids in Multiple Myeloma Progression, Drug Resistance, and Their Potential as Therapeutic Targets(Frontiers Media, 2022-06-08) Petrusca, Daniela N.; Lee, Kelvin P.; Galson, Deborah L.; Medicine, School of MedicineMultiple myeloma (MM) is an incapacitating hematological malignancy characterized by accumulation of cancerous plasma cells in the bone marrow (BM) and production of an abnormal monoclonal protein (M-protein). The BM microenvironment has a key role in myeloma development by facilitating the growth of the aberrant plasma cells, which eventually interfere with the homeostasis of the bone cells, exacerbating osteolysis and inhibiting osteoblast differentiation. Recent recognition that metabolic reprograming has a major role in tumor growth and adaptation to specific changes in the microenvironmental niche have led to consideration of the role of sphingolipids and the enzymes that control their biosynthesis and degradation as critical mediators of cancer since these bioactive lipids have been directly linked to the control of cell growth, proliferation, and apoptosis, among other cellular functions. In this review, we present the recent progress of the research investigating the biological implications of sphingolipid metabolism alterations in the regulation of myeloma development and its progression from the pre-malignant stage and discuss the roles of sphingolipids in in MM migration and adhesion, survival and proliferation, as well as angiogenesis and invasion. We introduce the current knowledge regarding the role of sphingolipids as mediators of the immune response and drug-resistance in MM and tackle the new developments suggesting the manipulation of the sphingolipid network as a novel therapeutic direction for MM.