Immunophenotyping characteristics and outcome of COVID-19 patients: peripheral blood CD8+T cell as a prognostic biomarker for patients with Nirmatrelvir.

Background: Nirmatrelvir has been authorized for the treatment of both hospitalized and non-hospitalized COVID-19 patients. However, the association between T lymphocyte subsets and the outcome of hospitalized COVID-19 patients treated with oral Nirmatrelvir has not been investigated. The objective of this study was to examine whether lymphocyte subsets could serve as biomarkers to assess the risk of mortality in COVID-19 patients undergoing Nirmatrelvir treatment, with the aim of enhancing medication management for COVID-19 patients. Methods: We conducted a retrospective cohort study at the Xiangya Hospital of Central South University in China between December 5, 2022 and January 31, 2023. The study reported demographic, clinical, T lymphocyte subsets, and inflammatory cytokine data of COVID-19 patients. We evaluated the associations of T lymphocyte subsets on admission with the composite outcome or death of patients using univariate and multivariable Cox regression analyses with hazards ratios (HRs) and 95% confidence intervals (CIs). Results: We identified 2118 hospitalized COVID-19 patients during the study period, and conducted a follow-up of up to 38 days. Of these, 131 patients received Nirmatrelvir, with 56 (42.7%) in the composite outcome group, and 75 (57.3%) in the non-composite outcome group. Additionally, 101 (77.1%) patients were discharged, while 30 (22.9%) died. Our results showed a significant decrease in the CD3+, CD4+, and CD8+ T cell counts of patients in the composite outcome group and mortality group compared to the non-composite outcome group and discharged group, respectively. Multivariate Cox regression analysis showed that the significant decrease in CD8+ T cell count in peripheral blood was independently associated with the composite outcome in COVID-19 patients treated with Nirmatrelvir, with an HR of 1.96 (95%CI: 1.01-3.80). The significant decrease in CD4+ and CD8+ T cell counts in peripheral blood increased the hazard of developing mortality, with HRs of 6.48 (95%CI: 1.47-28.63) and 3.75 (95%CI: 1.27-11.11), respectively. Conclusion: Our study revealed a significant positive correlation between a decrease in CD8+ T cell counts and progression and mortality of hospitalized COVID-19 patients treated with Nirmatrelvir. Lower counts (/µL) of CD8+ T cell (<201) were associated with a higher risk of in-hospital severity and death. Our findings may provide valuable references for physicians in optimizing the use of Nirmatrelvir.

Predictive and Prognostic Implications of Circulating CX3CR1+ CD8+ T Cells in Non-Small Cell Lung Cancer Patients Treated with Chemo-Immunotherapy.

Lack of reliable predictive biomarkers is a major limitation of combination therapy with chemotherapy and anti-programmed cell death protein 1/programmed death-ligand 1 (anti-PD-1/PD-L1) therapy (chemo-immunotherapy). We previously observed that the increase of peripheral blood CD8+ T cells expressing CX3CR1, a marker of differentiation, correlates with response to anti-PD-1 therapy; however, the predictive and prognostic value of T-cell CX3CR1 expression during chemo-immunotherapy is unknown. Here, we evaluated the utility of circulating CX3CR1+CD8+ T cells as a predictive correlate of response to chemo-immunotherapy in patients with non-small cell lung cancer (NSCLC). At least 10% increase of the CX3CR1+ subset in circulating CD8+ T cells from baseline (CX3CR1 score) was associated with response to chemo-immunotherapy as early as 4 weeks with 85.7% overall accuracy of predicting response at 6 weeks. Furthermore, at least 10% increase of the CX3CR1 score correlated with substantially better progression-free (P = 0.0051) and overall survival (P = 0.0138) on Kaplan-Meier analysis. Combined single-cell RNA/T-cell receptor (TCR) sequencing of circulating T cells from longitudinally obtained blood samples and TCR sequencing of tumor tissue from the same patient who received a long-term benefit from the treatment demonstrated remarkable changes in genomic and transcriptomic signatures of T cells as well as evolution of TCR clonotypes in peripheral blood containing highly frequent tumor-infiltrating lymphocyte repertoires overexpressing CX3CR1 early after initiation of the treatment despite stable findings of the imaging study. Collectively, these findings highlight the potential utility of T-cell CX3CR1 expression as a dynamic blood-based biomarker during the early course of chemo-immunotherapy and a marker to identify frequent circulating tumor-infiltrating lymphocyte repertoires. Significance: Current approaches to combined chemotherapy and anti-PD-1/PD-L1 therapy (chemo-immunotherapy) for patients with NSCLC are limited by the lack of reliable predictive biomarkers. This study shows the utility of T-cell differentiation marker, CX3CR1, as an early on-treatment predictor of response and changes in genomic/transcriptomic signatures of circulating tumor-infiltrating lymphocyte repertoires in patients with NSCLC undergoing chemo-immunotherapy.

Association between CD8+ tumor-infiltrating lymphocytes and prognosis of non-small cell lung cancer patients treated with PD-1/PD-L1 inhibitors: a systematic review and meta-analysis.

BACKGROUND: A meta-analysis method was used to investigate the prognostic value of CD8+ tumor-infiltrating lymphocytes (TILs) in non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 inhibitors. METHODS: A database search of PubMed, Embase, Web of Science and Cochrane Library up until 7 February, 2023. A clinical study on the relationship between CD8+ TILs and PD-1/PD-L1 inhibitors in the therapeutics of NSCLC. RevMan 5.3 and StataMP 17.0 software were used for meta-analysis. The outcome indicators incorporated overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). RESULTS: Nineteen articles with 1488 patients were included. The analysis results showed that high CD8+ TILs were associated with better OS (HR = 0.60, 95% CI: 0.46-0.77; P < 0.0001), PFS (HR = 0.68, 95% CI: 0.53-0.88; P = 0.003) and ORR (OR = 2.26, 95% CI: 1.52-3.36; P < 0.0001) in NSCLC patients treated with PD-1/PD-L1 inhibitors. Subgroup analysis indicated that patients with high CD8+ TILs had good clinical prognostic benefits whether the location of CD8+ TILs was intratumoral or stromal, and compared with East Asian, high CD8+ TILs in Caucasians showed a better prognosis. High CD8+ TILs in peripheral blood did not improve OS (HR = 0.83, 95% CI: 0.69-1.01; P = 0.06) and PFS (HR = 0.93, 95% CI: 0.61-1.14; P = 0.76) in NSCLC patients receiving PD-1/PD-L1 inhibitors. CONCLUSION: In spite of the location of CD8+ TILs, high densities of CD8+ TILs were predictive of treatment outcomes in NSCLC patients treated with PD-1/PD-L1 inhibitors. However, high CD8+ TILs in peripheral blood had no predictive effect.

Particulate Matter and Its Components Induce Alteration on the T-Cell Response: A Population Biomarker Study.

Compared with the T-cell potential of particulate matter (PM) in animal studies, comprehensive evaluation on the impairments of T-cell response and exposure-response from PM and its components in human population is limited. There were 768 participants in this study. We measured environmental PM and its polycyclic aromatic hydrocarbons (PAHs) and metals and urinary metabolite levels of PAHs and metals among population. T lymphocyte and its subpopulation (CD4+ T cells and CD8+ T cells) and the expressions of T-bet, GATA3, RORγt, and FoxP3 were measured. We explored the exposure-response of PM compositions by principal component analysis and mode of action by mediation analysis. There was a significant decreasing trend for T lymphocytes and the levels of T-bet and GATA3 with increased PM levels. Generally, there was a negative correlation between PM, urinary 1-hydroxypyrene, urinary metals, and the levels of T-bet and GATA3 expression. Additionally, CD4+ T lymphocytes were found to mediate the associations of PM2.5 with T-bet expression. PM and its bound PAHs and metals could induce immune impairments by altering the T lymphocytes and genes of T-bet and GATA3.

E3 Ubiquitin Ligase RNF125 Suppresses Immune Escape in Head and Neck Squamous Cell Carcinoma by Regulating PD-L1 Expression.

Head and neck squamous cell carcinoma (HNSCC) is a lethal malignancy. Given the essential roles of E3 ligases in cancer immunotherapies, this paper explored the effect of E3 ubiquitin ligase ring finger protein 125 (RNF125) on immune escape in HNSCC. After delivering overexpressed (oe)-RNF125, interferon-gamma, or oe-programmed death-ligand 1 (PD-L1) into HNSCC cells and cell culture with carboxyfluorescein succinimidyl ester-labeled CD8+ T cells, RNF125 and PD-L1 levels were determined via RT-qPCR and Western blot, with HNSCC cell behaviors assessed via colony formation assay, Transwell assays and flow cytometry, and inflammatory factors measured via ELISA. PD-L1 ubiquitination level and PD-L1's interaction with RNF125 were analyzed via co-immunoprecipitation. The in vivo action of RNF125 on HNSCC was validated via nude mouse tumorigenicity assay. Briefly, RNF125 was weakly expressed in HNSCC cells. RNF125 overexpression inhibited immune escape of HNSCC cells, evidenced by decreased TSCCA cell proliferation, migration, and invasion, increased CD8+ T cell proliferation, and elevated IL-2 and TNF-α levels. RNF125 downregulated PD-L1 in TSCCA cells and facilitated PD-L1 ubiquitinational degradation. PD-L1 overexpression partially abated RNF125-mediated suppression on TSCCA cell immune escape. Moreover, RNF125 suppressed tumorigenesis and tumor growth in vivo. Overall, RNF125 promoted PD-L1 ubiquitinational degradation, hence inhibiting immune escape in HNSCC.

Duodenal CD8+ T resident memory cell apoptosis contributes to gut barrier dysfunction and microbial translocation in early alcohol-associated liver disease in humans.

BACKGROUND: Intestinal T cells are key in gut barrier function. Their role in early stages of alcohol-associated liver disease (ALD) remain unknown. AIM: To explore the links between intestinal T cells, microbial translocation and ALD METHODS: Patients with alcohol use disorder (AUD) following a rehabilitation programme were compared to subjects with non-alcoholic fatty liver disease (NAFLD) and healthy controls. Clinical and laboratory data (liver stiffness, controlled attenuation parameter, AST, ALT, K18-M65) served to identify AUD patients with isolated steatosis (minimal liver disease) or steatohepatitis/fibrosis (ALD). Serum microbial translocation markers were measured by ELISA, duodenal and plasma levels of sphingolipids by targeted LC-MS. T lymphocytes in duodenal biopsies were characterised by immunohistochemistry, flow cytometry and RNA sequencing on FACS-sorted cells. Mechanisms for T-cell alterations were assessed in vitro. RESULTS: Patients with ALD, but not those with minimal liver disease, showed reduced numbers of duodenal CD8+ T resident memory (TRM) cells compared to controls or patients with NAFLD. TRM transcriptomic analysis, in vitro analyses and pharmacological inhibition of cathepsin B confirmed TRM apoptosis driven by lysosomal membrane permeabilisation and cathepsin B release into the cytosol. Altered lipid metabolism and increased duodenal and plasma sphingolipids correlated with apoptosis. Dihydroceramide dose-dependently reduced viability of TRM. Duodenal TRM phenotypic changes, apoptosis and transcriptomic alterations correlated with increased levels of microbial translocation markers. Short-term abstinence did not reverse TRM cell death in patients with ALD. CONCLUSIONS: Duodenal CD8+ TRM apoptosis related to functional changes in lysosomes and lipid metabolism points to impaired gut adaptive immunity specifically in patients with AUD who developed early ALD.

Sensory Neurotransmitter Calcitonin Gene-Related Peptide Modulates Tumor Growth and Lymphocyte Infiltration in Oral Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma are highly innervated by peripheral sensory neurons. Local neurotransmitter release (e.g., calcitonin gene-related peptide (CGRP)) from sensory neurons innervating cancer is linked to tumorigenesis. CGRP-immunoreactive nerve presence comprised 9.53±1.9% of total nerve area across 11 HNSCC patients. A syngeneic tongue tumor transplant mouse model of oral cancer and a global Calca knockout mouse (CGRPKO ) are used to investigate the impact of CGRP signaling on tumor growth and the associated immune response in vivo. In tumor-bearing CGRPKO mice, there is a significant reduction in tumor size over time compared to wildtype mice using two different mouse oral cancer cell lines. Furthermore, tumor tissue from CGRPKO mice had a significant increase in tumor-infiltrating CD4+ T cells, cytotoxic CD8+ T cells, and NK1.1+ NK cells compared to wildtype. Fluorescent-activated cell sorting and real-time qPCR are used to confirm that CD4+ T cells are isolated from tumor-bearing wildtype mice containing a high expression of Ramp1 compared to sham mice. These data suggest that sensory neurotransmitter CGRP may modulate oral cancer progression via tumor immunosurveillance. Understanding the relationship between sensory neurons and cancer will aid in repurposing clinically available nervous system drugs for the treatment of cancer.

Effect of Exercise on Acute Senescent Lymphocyte Counts: A Systematic Review and Meta-Analysis.

BACKGROUND: Highly differentiated, senescent lymphocytes are pro-inflammatory and contribute to age-related systemic inflammation, called inflammageing. There are several reports of acute changes in senescent lymphocyte counts post exercise, which potentially have consequences for systemic inflammation. However, there is little consensus since the studies differ with respect to participants, exercise protocols, cellular markers assessed, and the time point of assessment post exercise. OBJECTIVE: We performed a systematic review and meta-analysis to assess the impact of exercise on senescent lymphocyte counts in blood immediately, 1 h and 2 h post exercise. METHODS: The search was performed in PubMed (MEDLINE), Web of Science, Embase, Scopus, and Cochrane, on January 11, 2021. The 13 studies selected tested aerobic exercise effects, mainly in young men. They assessed the counts of lymphocytes (CD4 T cells, CD8 T cells, and NK cells), with the following immune cell marker combinations: KLRG1+, CD57+ (only NK cells), EMRA T cells (CD45RA+CCR7-CD28-CD27-), CD28-CD27-, KLRG1+CD28-, and CD28-. Independent extraction of articles was done by 2 researchers. RESULTS: Standardized mean difference (SMD) and 95% confidence interval between baseline and post exercise showed significant increase (SMD >0.9, p < 0.003) in all types of senescent lymphocytes counts immediately post exercise. At 1 h post exercise, senescent CD4 T cells returned to baseline values (p = 0.74), CD8 T cells were reduced (-0.26 [-0.41; -0.11], p = 0.001), and senescent NK cells were raised (0.62 [0.14; 1.10], p = 0.01) above baseline. By 2 h post exercise, senescent CD4 T cells were reduced (-0.94 [-1.40; -0.48], p < 0.001), CD8 T cells remained below baseline (-0.53 [-1.04; -0.009], p = 0.04), and NK cells had returned to baseline values (-0.29 [-0.64; 0.07], p = 0.11). The main determinants of heterogeneity between studies were cytomegalovirus (CMV) serostatus and the characteristics of exercise protocols. CMV+ individuals had a higher immediate lymphocytosis and 1 h post lymphopenia than CMV- individuals. Exercise performed at higher intensities and shorter durations led to higher magnitude of change in senescent lymphocyte counts at all time-points. CONCLUSION: The differing effects of exercise on senescent NK cells and CD4 and CD8 T cells suggest differing susceptibility to factors modulating lymphocyte extravasation such as adrenaline and exercise intensity.

Prognostic impact of tumor-infiltrating lymphocytes in non-small cell lung carcinomas.

INTRODUCTION: Tumor-infiltrating lymphocytes represent a pivotal component of the host anti-tumor response. Thus, they considerably influence the evolution of cancers including non-small cell lung carcinomas. Even if, this important role is consensual, many discordant results are published in the literature about the prognostic role of the different populations of tumor-infiltrating lymphocytes. The aim of our work was to evaluate the prognostic impact of CD8+, CD4+, and forkhead box protein P3+ lymphocytes in the tumor microenvironment of non-small cell lung carcinomas. METHODS: We conducted a retrospective descriptive study, which included non-small cell lung carcinomas diagnosed in the department of pathology and followed in the medical oncology department of the same hospital between 2011 and 2015. Tumor-infiltrating lymphocytes were analyzed by the immunohistochemical method for forkhead box protein P3, CD4, and CD8. Intratumoral and stromal-labeled lymphocytes were quantified by manual counting at high magnification (×400). Forkhead box protein P3+/CD8+, forkhead box protein P3+/CD4+, and CD8+/CD4+ ratios were subsequently calculated. The prognostic value of tumor-infiltrating lymphocytes was assessed in respect of overall survival, recurrence-free survival, and relapse-free survival. RESULTS: Thirty-nine patients were included. The mean age of patients was 59.6 years. A complete surgical resection (p = 0.009), and a CD8/CD4 ratio (p = 0.008) were prognostic factors for overall survival. Complete surgical resection (p = 0.003), the forkhead box protein P3/CD8 (p = 0.005), and forkhead box protein P3/CD4 (p = 0.037) ratios were prognostic factors for recurrence-free survival. The CD8+ tumor-infiltrating lymphocytes rate (p = 0.037) was a prognostic factor for relapse-free survival with a threshold of 67.8/high power field. Microscopic subtype (p = 0.037) was a prognostic factor for relapse-free survival when only adenocarcinoma and squamous cell carcinoma were considered. In multivariate analysis, age (p = 0.004) and a CD8/CD4 ratio (p = 0.016) were independent predictors of overall survival. CONCLUSION: Despite the limitations of our study, our results confirm the prognostic value of tumor-infiltrating lymphocytes in non-small cell lung carcinomas and the importance of the combined quantification of their different subpopulations.

Mechanistic diversity in MHC class I antigen recognition.

Throughout its evolution, the human immune system has developed a plethora of strategies to diversify the antigenic peptide sequences that can be targeted by the CD8+ T cell response against pathogens and aberrations of self. Here we provide a general overview of the mechanisms that lead to the diversity of antigens presented by MHC class I complexes and their recognition by CD8+ T cells, together with a more detailed analysis of recent progress in two important areas that are highly controversial: the prevalence and immunological relevance of unconventional antigen peptides; and cross-recognition of antigenic peptides by the T cell receptors of CD8+ T cells.

HIV-1-Specific CD11c+ CD8+ T Cells Display Low PD-1 Expression and Strong Anti-HIV-1 Activity.

Exhaustion of HIV-1-specific CD8+ T cells prevents optimal control of HIV-1 infection. Identifying unconventional CD8+ T cell subsets to effectively control HIV-1 replication is vital. In this study, the role of CD11c+ CD8+ T cells during HIV-1 infection was evaluated. The frequencies of CD11c+ CD8+ T cells significantly increased and were negatively correlated with viral load in HIV-1-infected treatment-naïve patients. HIV-1-specific cells were enriched more in CD11c+ CD8+ T cells than in CD11c- CD8+ T cells, which could be induced by HIV-1-derived overlapping peptides, marking an HIV-1-specific CD8+ T cell population. This subset expressed higher levels of activating markers (CD38 and HLA-DR), cytotoxic markers (granzyme B, perforin, and CD107a), and cytokines (IL-2 and TNF-α), with lower levels of PD-1 compared to the CD11c- CD8+ T cell subset. In vitro analysis verified that CD11c+ CD8+ T cells displayed a stronger HIV-1-specific killing capacity than the CD11c- counterparts. These findings indicate that CD11c+ CD8+ T cells have potent immunotherapeutic efficacy in controlling HIV-1 infection.

Rapid Identification of the Tumor-Specific Reactive TIL Repertoire via Combined Detection of CD137, TNF, and IFNγ, Following Recognition of Autologous Tumor-Antigens.

Detecting the entire repertoire of tumor-specific reactive tumor-infiltrating lymphocytes (TILs) is essential for investigating their immunological functions in the tumor microenvironment. Current in vitro assays identifying tumor-specific functional activation measure the upregulation of surface molecules, de novo production of antitumor cytokines, or mobilization of cytotoxic granules following recognition of tumor-antigens, yet there is no widely adopted standard method. Here we established an enhanced, yet simple, method for identifying simultaneously CD8+ and CD4+ tumor-specific reactive TILs in vitro, using a combination of widely known and available flow cytometry assays. By combining the detection of intracellular CD137 and de novo production of TNF and IFNγ after recognition of naturally-presented tumor antigens, we demonstrate that a larger fraction of tumor-specific and reactive CD8+ TILs can be detected in vitro compared to commonly used assays. This assay revealed multiple polyfunctionality-based clusters of both CD4+ and CD8+ tumor-specific reactive TILs. In situ, the combined detection of TNFRSF9, TNF, and IFNG identified most of the tumor-specific reactive TIL repertoire. In conclusion, we describe a straightforward method for efficient identification of the tumor-specific reactive TIL repertoire in vitro, which can be rapidly adopted in most cancer immunology laboratories.

Prognostic Role of Tumoral PD-L1 and IDO1 Expression, and Intratumoral CD8+ and FoxP3+ Lymphocyte Infiltrates in 132 Primary Cutaneous Merkel Cell Carcinomas.

The association of immune markers and clinicopathologic features and patient outcome has not been extensively studied in Merkel cell carcinoma (MCC). We correlated tumoral PD-L1 and IDO1 expression, and intratumoral CD8+ and FoxP3+ lymphocytes count with clinicopathologic variables, Merkel cell polyomavirus (MCPyV) status, and patient outcomes in a series of 132 MCC. By univariate analyses, tumoral PD-L1 expression >1% and combined tumoral PD-L1 >1% and high intratumoral FoxP3+ lymphocyte count correlated with improved overall survival (OS) (p = 0.016, 0.0072), MCC-specific survival (MSS) (p = 0.019, 0.017), and progression-free survival (PFS) (p = 0.043, 0.004, respectively). High intratumoral CD8+ and FoxP3+ lymphocyte count correlated with longer MSS (p = 0.036) and improved PFS (p = 0.047), respectively. Ulceration correlated with worse OS and worse MSS. Age, male gender, and higher stage (3 and 4) significantly correlated with worse survival. MCPyV positivity correlated with immune response. By multivariate analyses, only ulceration and age remained as independent predictors of worse OS; gender and stage remained for shorter PFS. Tumoral PD-L1 expression and increased density of intratumoral CD8+ lymphocytes and FoxP+ lymphocytes may represent favorable prognosticators in a subset of MCCs. Tumoral PD-L1 expression correlated with intratumoral CD8+ and FoxP3+ lymphocytes, which is supportive of an adaptive immune response.

Measuring the effect of drug treatments on primary human CD8+ T cell activation and cytolytic potential.

CD8+ T cells are key effector cells in adaptive immune responses against intracellular pathogens and cancer cells. Systemic drug treatments, like chemotherapy, may positively or negatively affect CD8+ T cell function. In this protocol, we describe robust and optimized ex vivo polyclonal activation and cell culture conditions to measure drug treatments' effects on primary human CD8+ T cell activation and cytolytic potential. We provide streamlined methods for measuring effector cytokines and activation markers of CD8+ T cells via flow cytometry. For complete details on the use and execution of this protocol, please refer to Loo Yau et al. (2021).

Temporal analysis of T-cell receptor-imposed forces via quantitative single molecule FRET measurements.

Mechanical forces acting on ligand-engaged T-cell receptors (TCRs) have previously been implicated in T-cell antigen recognition, yet their magnitude, spread, and temporal behavior are still poorly defined. We here report a FRET-based sensor equipped either with a TCR-reactive single chain antibody fragment or peptide-loaded MHC, the physiological TCR-ligand. The sensor was tethered to planar glass-supported lipid bilayers (SLBs) and informed most directly on the magnitude and kinetics of TCR-imposed forces at the single molecule level. When confronting T-cells with gel-phase SLBs we observed both prior and upon T-cell activation a single, well-resolvable force-peak of approximately 5 pN and force loading rates on the TCR of 1.5 pN per second. When facing fluid-phase SLBs instead, T-cells still exerted tensile forces yet of threefold reduced magnitude and only prior to but not upon activation.

Alterations in regulatory T cells and immune checkpoint molecules in pancreatic cancer patients receiving FOLFIRINOX or gemcitabine plus nab-paclitaxel.

PURPOSE: This pilot study aimed on generating insight on alterations in circulating immune cells during the use of FOLFIRINOX and gemcitabine/nab-paclitaxel in pancreatic ductal adenocarcinoma (PDAC). PATIENTS AND METHODS: Peripheral blood mononuclear cells were isolated before and 30 days after initiation of chemotherapy from 20 patients with advanced PDAC. Regulatory T cells (FoxP3+) and immune checkpoints (PD-1 and TIM-3) were analyzed by flow cytometry and immunological changes were correlated with clinical outcome. RESULTS: Heterogeneous changes during chemotherapy were observed in circulating T-cell subpopulations with a pronounced effect on PD-1+ CD4+/CD8+ T cells. An increase in FoxP3+ or PD-1+ T cells had no significant effect on survival. An increase in TIM3+/CD8+ (but not TIM3+/CD4+) T cells was associated with a significant inferior outcome: median progression-free survival in the subgroup with an increase of TIM-3+/CD8+ T cells was 6.0 compared to 14.0 months in patients with a decrease/no change (p = 0.026); corresponding median overall survival was 13.0 and 20.0 months (p = 0.011), respectively. CONCLUSIONS: Chemotherapy with FOLFIRNOX or gemcitabine/nab-paclitaxel induces variable changes in circulating T-cell populations that may provide prognostic information in PDAC.

Caloric Restriction Impairs Regulatory T cells Within the Tumor Microenvironment After Radiation and Primes Effector T cells.

Outcomes for triple negative breast cancer (TNBC) are poor and may be improved by increasing CD8+ tumor infiltrating lymphocytes (TIL) to augment antitumor immunity. Radiation (RT) can promote immunogenic cell death with increased antitumor T cell activity but also stimulates suppressive regulatory T cells (Tregs). Because metabolic alterations affect immune homeostasis and prior studies show caloric restriction (CR) combined with RT improves preclinical TNBC outcomes, we hypothesized that CR augments RT, in part, by altering intratumoral immunity. Using an in vivo model of TNBC, we treated mice with ad libitum (AL) diet, radiation, a CR diet, or CR + RT, and demonstrated an immune suppressive environment with a significant increase in CD4+ CD25+Foxp3+ Tregs after RT but not in CR-fed mice. CD8:Treg ratio in CR + RT TIL increased 4-fold compared with AL + RT mice. In vivo CD8 depletion was performed to assess the role of effector T cells in mitigating the effects of CR, and it was found that in mice undergoing CR, depletion of CD8 T cells resulted in increased tumor progression and decreased median survival compared with isotype control-treated mice. In addition, PD-1 expression on CD3+CD8+ T cells within the tumor microenvironment was significantly increased in CR + RT versus AL + RT treated mice as per immunofluorescence. Serum from breast cancer patients undergoing RT alone or CR and RT was collected pre- and postintervention, and a cytokine array demonstrated that patients treated with CR + RT had notable decreases in immunosuppressive cytokines such as IL-2Rγ, IL-10Rß, and TGF-ß2 and 3 compared with patients receiving RT alone. In conclusion, combining CR with RT decreases intratumoral Tregs, increases CD8:Treg, and increases PD-1 expression via a process dependent on CD8 T cells in a TNBC model. Breast cancer patients undergoing CR concurrently with RT also had significant reduction in immunosuppressive cytokine levels compared with those receiving RT alone.

Atypical BCL6/GATA3+ Primary Cutaneous Acral CD8-Positive T-Cell Lymphoma: A Diagnostic Challenge.

ABSTRACT: Primary cutaneous acral CD8-positive T-cell lymphoma consists of slow-growing nodules in acral sites with a histopathology, suggesting high-grade lymphoma despite the indolent clinical course. It has been recently included in WHO-EORTC classification for primary cutaneous lymphomas as a provisional entity. A correct diagnosis of this entity is important because its differential diagnosis include more aggressive cutaneous lymphomas. We present a 53-year-old woman with an indolent solitary nodule on her right leg, which histopathologically showed features of CD8-positive T-cell lymphoma, although with some peculiarities, including epidermotropism, absence of CD68 expression, and positivity for GATA3 and Bcl6 in neoplastic cells. This case could contribute to better define the spectrum of this rare cutaneous lymphoma.

Inducible de novo expression of neoantigens in tumor cells and mice.

Inducible expression of neoantigens in mice would enable the study of endogenous antigen-specific naïve T cell responses in disease and infection, but has been difficult to generate because leaky antigen expression in the thymus results in central T cell tolerance. Here we develop inversion-induced joined neoantigen (NINJA), using RNA splicing, DNA recombination and three levels of regulation to prevent leakiness and allow tight control over neoantigen expression. We apply NINJA to create tumor cell lines with inducible neoantigen expression, which could be used to study antitumor immunity. We also show that the genetic regulation in NINJA mice bypasses central and peripheral tolerance mechanisms and allows for robust endogenous CD8 and CD4 T cell responses on neoantigen induction in peripheral tissues. NINJA will enable studies of how T cells respond to defined neoantigens in the context of peripheral tolerance, transplantation, autoimmune diseases and cancer.

Stem-like CD8 T cells mediate response of adoptive cell immunotherapy against human cancer.

Adoptive T cell therapy (ACT) using ex vivo-expanded autologous tumor-infiltrating lymphocytes (TILs) can mediate complete regression of certain human cancers. The impact of TIL phenotypes on clinical success of TIL-ACT is currently unclear. Using high-dimensional analysis of human ACT products, we identified a memory-progenitor CD39-negative stem-like phenotype (CD39-CD69-) associated with complete cancer regression and TIL persistence and a terminally differentiated CD39-positive state (CD39+CD69+) associated with poor TIL persistence. Most antitumor neoantigen-reactive TILs were found in the differentiated CD39+ state. However, ACT responders retained a pool of CD39- stem-like neoantigen-specific TILs that was lacking in ACT nonresponders. Tumor-reactive stem-like TILs were capable of self-renewal, expansion, persistence, and superior antitumor response in vivo. These data suggest that TIL subsets mediating ACT response are distinct from TIL subsets enriched for antitumor reactivity.