Obesity reshapes regulatory T cells in the visceral adipose tissue by disrupting cellular cholesterol homeostasis.

Regulatory T cells (T) accumulate in the visceral adipose tissue (VAT) to maintain systemic metabolic homeostasis but decline during obesity. Here, we explored the metabolic pathways controlling the homeostasis, composition, and function of VAT T under normal and high-fat diet feeding conditions. We found that cholesterol metabolism was specifically up-regulated in ST2 VAT T subsets.

An early precursor CD8 T cell that adapts to acute or chronic viral infection.

This study examines the origin and differentiation of stem-like CD8+ T cells that are essential for sustained T cell immunity in chronic viral infections and cancer and also play a key role in PD-1 directed immunotherapy. These PD-1+ TCF-1+ TOX+ stem-like CD8+ T cells, also referred to as precursors of exhausted T cells, have a distinct program that allows them to adapt to chronic antigen stimulation. Using the mouse model of chronic LCMV infection we found that virus specific stem-like CD8+ T cells are generated early (day 5) during chronic infection suggesting that this crucial fate commitment occurs irrespective of infection outcome.

Differentiation fate of a stem-like CD4 T cell controls immunity to cancer.

The T cell response to cancer controls disease progression and response to immunotherapy. Despite extensive knowledge regarding CD8 T cells, how CD4 T cells contribute to this process is less well understood. Here we identified a population of PD1TCF1 CD4 T cells with stem-like properties that are capable of self-renewal and differentiation into canonical CD4 effector cells.

Pre-operative stereotactic radiosurgery and peri-operative dexamethasone for resectable brain metastases: a two-arm pilot study evaluating clinical outcomes and immunological correlates.

Enhancing the efficacy of immunotherapy in brain metastases (BrM) requires an improved understanding of the immune composition of BrM and how this is affected by radiation and dexamethasone. Our two-arm pilot study (NCT04895592) allocated 26 patients with BrM to either low (Arm A) or high (Arm B) dose peri-operative dexamethasone followed by pre-operative stereotactic radiosurgery (pSRS) and resection (n= 13 per arm). The primary endpoint, a safety analysis at 4 months, was met.

Neoadjuvant cabozantinib restores CD8+ T cells in patients with locally advanced non-metastatic clear cell renal cell carcinoma: a phase 2 trial.

Cabozantinib is an oral multikinase inhibitor approved for treatment in metastatic renal cell carcinoma (RCC). We hypothesized that neoadjuvant cabozantinib could downstage localized tumors, facilitating partial nephrectomy, and facilitating surgery in patients with locally advanced tumors that would require significant adjacent organ resection. We, therefore, conducted a phase 2, single-arm trial of cabozantinib treatment for 12 weeks in 17 patients with locally advanced biopsy-proven non-metastatic clear cell RCC before surgical resection.

CD28-CD57+ T cells from head and neck cancer patients produce high levels of cytotoxic granules and type II interferon but are not senescent.

T lymphocytes expressing CD57 and lacking costimulatory receptors CD27/CD28 have been reported to accumulate with aging, chronic infection, and cancer. These cells are described as senescent, with inability to proliferate but enhanced cytolytic and cytokine-producing capacity. However, robust functional studies on these cells taken directly from cancer patients are lacking.

Distinct SIV-specific CD8 T cells in the lymph node exhibit simultaneous effector and stem-like profiles and are associated with limited SIV persistence.

Human immunodeficiency virus (HIV) cure efforts are increasingly focused on harnessing CD8 T cell functions, which requires a deeper understanding of CD8 T cells promoting HIV control. Here we identifiy an antigen-responsive TOXTCF1CD39CD8 T cell population with high expression of inhibitory receptors and low expression of canonical cytolytic molecules. Transcriptional analysis of simian immunodeficiency virus (SIV)-specific CD8 T cells and proteomic analysis of purified CD8 T cell subsets identified TOXTCF1CD39CD8 T cells as intermediate effectors that retained stem-like features with a lineage relationship with terminal effector T cells.

Impact of immunotherapy time-of-day infusion on survival and immunologic correlates in patients with metastatic renal cell carcinoma: a multicenter cohort analysis.

Background: Recent studies have demonstrated that earlier time-of-day infusion of immune checkpoint inhibitors (ICIs) is associated with longer progression-free survival (PFS) and overall survival (OS) among patients with metastatic melanoma and non-small cell lung cancer. These data are in line with growing preclinical evidence that the adaptive immune response may be more effectively stimulated earlier in the day. We sought to determine the impact of time-of-day ICI infusions on outcomes among patients with metastatic renal cell carcinoma (mRCC).

Radiation and anti-PD-L1 synergize by stimulating a stem-like T cell population in the tumor-draining lymph node.

Radiotherapy (RT) and anti-PD-L1 synergize to enhance local and distant (abscopal) tumor control. However, clinical results in humans have been variable. With the goal of improving clinical outcomes, we investigated the underlying synergistic mechanism focusing on a CD8+ PD-1+ Tcf-1+ stem-like T cell subset in the tumor-draining lymph node (TdLN).

Early generation of a precursor CD8 T cell that can adapt to acute or chronic viral infection.

Virus specific PD-1+ TCF-1+ TOX+ stem-like CD8+ T cells are essential for maintaining T cell responses during chronic infection and are also critical for PD-1 directed immunotherapy. In this study we have used the mouse model of chronic LCMV infection to examine when these virus specific stem-like CD8+ T cells are generated during the course of chronic infection and what is the role of antigen in maintaining the stem-like program. We found that these stem-like CD8+ T cells are generated early (day 5) during chronic infection and that antigen is essential for maintaining their stem-like program.

Localized high-risk prostate cancer harbors an androgen receptor low subpopulation susceptible to HER2 inhibition.

Patients diagnosed with localized high-risk prostate cancer have higher rates of recurrence, and the introduction of neoadjuvant intensive hormonal therapies seeks to treat occult micrometastatic disease by their addition to definitive treatment. Sufficient profiling of baseline disease has remained a challenge in enabling the in-depth assessment of phenotypes associated with exceptional vs. poor pathologic responses after treatment.

Case Report: Exceptional response to nivolumab plus cabozantinib in a patient with extrarenal clear cell renal cell carcinoma.

Extrarenal clear cell renal cell carcinoma (eccRCC) is a rare type of RCC that arises in areas other than the kidney. Given its rarity, consensus guidelines for optimal treatment of eccRCC have not been established, and the literature is lacking any reports of patient response to systemic therapy and any reports of administration of immunotherapy to patients with ecRCC. Here, we present the case of a patient in their 60s with eccRCC arising in the spleen.

Characteristics and anatomic location of PD-1TCF1 stem-like CD8 T cells in chronic viral infection and cancer.

CD8 T cells play an essential role in antitumor immunity and chronic viral infections. Recent findings have delineated the differentiation pathway of CD8 T cells in accordance with the progenitor-progeny relationship of TCF1 stem-like and Tim-3TCF1 more differentiated T cells. Here, we investigated the characteristics of stem-like and differentiated CD8 T cells isolated from several murine tumor models and human lung cancer samples in terms of phenotypic and transcriptional features as well as their location compared to virus-specific CD8 T cells in the chronically lymphocytic choriomeningitis virus (LCMV)-infected mice.

Immune-Related Adverse Events and Clinical Outcomes in Advanced Urothelial Cancer Patients Treated With Immune Checkpoint Inhibitors.

Background: In advanced urothelial cancers (UC), immune checkpoint inhibitors (ICI) show promise as a durable therapy. Immune-related adverse events (irAEs), a side effect of ICIs, may serve as an indicator of beneficial response. We investigated the relationship between irAEs and clinical outcomes in patients with advanced UC who received ICI.

Immune niches in brain metastases contain TCF1+ stem-like T cells, are associated with disease control and are modulated by preoperative SRS.

The CD8 T-cell response is prognostic for survival outcomes in several tumor types. However, whether this extends to tumors in the brain, an organ with barriers to T cell entry, remains unclear. Here, we analyzed immune infiltration in 67 brain metastasis (BrM) and found high frequencies of PD1 TCF1 stem-like CD8 T-cells and TCF1 effector-like cells.

CD8 T cell activation in cancer comprises an initial activation phase in lymph nodes followed by effector differentiation within the tumor.

Improvements in tumor immunotherapies depend on better understanding of the anti-tumor T cell response. By studying human tumor-draining lymph nodes (TDLNs), we found that activated CD8 T cells in TDLNs shared functional, transcriptional, and epigenetic traits with TCF1 stem-like cells in the tumor. The phenotype and TCR overlap suggested that these TDLN cells were precursors to tumor-resident stem-like CD8 T cells.

Longitudinal Analysis of the Phenotype, Transcriptional Profile, and Anatomic Location of Memory CD8 T Cell Subsets after Acute Viral Infection.

Increased demand for novel, highly effective vaccination strategies necessitates a better understanding of long-lived memory CD8 T cell differentiation. To achieve this understanding, we used the mouse model of acute lymphocytic choriomeningitis virus (LCMV) infection. We reexamined classical memory CD8 T cell subsets and performed in-depth, longitudinal analysis of their phenotype, transcriptional programming, and anatomic location within the spleen.

Targeting vasoactive intestinal peptide-mediated signaling enhances response to immune checkpoint therapy in pancreatic ductal adenocarcinoma.

A paucity of effector T cells within tumors renders pancreatic ductal adenocarcinoma (PDAC) resistant to immune checkpoint therapies. While several under-development approaches target immune-suppressive cells in the tumor microenvironment, there is less focus on improving T cell function. Here we show that inhibiting vasoactive intestinal peptide receptor (VIP-R) signaling enhances anti-tumor immunity in murine PDAC models.

PD-1 combination therapy with IL-2 modifies CD8 T cell exhaustion program.

Combination therapy with PD-1 blockade and IL-2 is highly effective during chronic lymphocytic choriomeningitis virus infection. Here we examine the underlying basis for this synergy. We show that PD-1 + IL-2 combination therapy, in contrast to PD-1 monotherapy, substantially changes the differentiation program of the PD-1TCF1 stem-like CD8 T cells and results in the generation of transcriptionally and epigenetically distinct effector CD8 T cells that resemble highly functional effector CD8 T cells seen after an acute viral infection.

PD-1-cis IL-2R agonism yields better effectors from stem-like CD8 T cells.

Expansion and differentiation of antigen-experienced PD-1TCF-1 stem-like CD8 T cells into effector cells is critical for the success of immunotherapies based on PD-1 blockade. Hashimoto et al. have shown that, in chronic infections, administration of the cytokine interleukin (IL)-2 triggers an alternative differentiation path of stem-like T cells towards a distinct population of 'better effector' CD8 T cells similar to those generated in an acute infection.

TGF-β regulates the stem-like state of PD-1+ TCF-1+ virus-specific CD8 T cells during chronic infection.

Recent studies have defined a novel population of PD-1+ TCF-1+ stem-like CD8 T cells in chronic infections and cancer. These quiescent cells reside in lymphoid tissues, are critical for maintaining the CD8 T cell response under conditions of persistent antigen, and provide the proliferative burst after PD-1 blockade. Here we examined the role of TGF-β in regulating the differentiation of virus-specific CD8 T cells during chronic LCMV infection of mice.

Clinical outcome following checkpoint therapy in renal cell carcinoma is associated with a burst of activated CD8 T cells in blood.

Purpose: Checkpoint therapy is now the cornerstone of treatment for patients with renal cell carcinoma (RCC) with advanced disease, but biomarkers are lacking to predict which patients will benefit. This study proposes potential immunological biomarkers that could developed for predicting therapeutic response in patients with RCC.

Methods: Using flow cytometry, RNA sequencing, and T-cell receptor (TCR) sequencing, we investigated changes in T cells in the peripheral blood of patients with advanced RCC after receiving immunotherapy.

New epigenetic regulators of T cell exhaustion.

In this issue of Cancer Cell, Belk et al. perform an in vitro CRISPR screen to identify genes that regulate CD8 T cell exhaustion. They find several genes related to epigenetic modification and show that by eliminating Arid1a, CD8 T cells retain proliferative and cytotoxic function in vivo, leading to better anti-tumor activity.