Tumor-Infiltrating PD-1+ Immune Cell Density is Associated with Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer.

BACKGROUND: Elevated tumor-infiltrating T-cell density is associated with favorable outcomes in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (CRT). Here, we evaluated the significance of programmed cell death 1 (PD-1)-positive cells, regulatory T cells, and macrophages in response to CRT and prognosis. PATIENTS AND METHODS: We assessed CD8+, PD-1+, FOXP3+, CD68+, and CD163+ intratumoral and stromal cell densities by immunohistochemistry using pre-treatment biopsies from 275 patients with rectal cancer treated with neoadjuvant CRT. We determined the impact of these measurements on response to CRT and survival. Response to CRT was determined by tumor regression grade (TRG) of surgical specimens, with good responders defined as TRG3-4. RESULTS: Intratumoral CD8+ and PD-1+ cell densities were significantly higher in good responders than in poor responders, whereas stromal CD68+ cell density was significantly lower in good responders as compared with poor responders. The multivariable analysis revealed high intratumoral CD8+ and PD-1+ cell densities to be independently associated with good responders (CD8: odds ratio [OR], 2.27; 95% confidence interval [CI], 1.21 - 4.34, P = .010; PD-1: OR, 1.97; 95%CI, 1.03 - 3.84, P = .039), and improved recurrence-free survival (CD8: hazard ratio [HR], 0.56; 95%CI, 0.32 - 0.98, P = .044; PD-1: HR, 0.37; 95%CI, 0.19 - 0.71, P = .002). Only high intratumoral CD8+ cell density was associated with improved overall survival (P = .022). CONCLUSION: Pre-treatment high intratumoral PD-1+ and CD8+ cell densities were independently associated with good response to CRT and improved recurrence-free survival, with high intratumoral CD8+ cell density additionally associated with improved overall survival. These values may serve as predictive and prognostic biomarkers in rectal cancer.

Microsatellite instability in Chinese gastric cancer and its correlation with clinical characteristics.

BACKGROUND: Microsatellite instability (MSI) remains a focus of interest in cancer research, but the characteristics of MSI in gastric cancer (GC) are ambiguous. METHODS: In this retrospective study, we analyzed the prevalence of MSI and the expression of programmed death-ligand 1 (PD-L1) and cluster of differentiation 8 (CD8) cells in Chinese GC patients. A total of 393 GC patients admitted to two centers from January 2010 to December 2017 were enrolled. RESULTS: The prevalence of MSI in this cohort was 3.4% and most frequently occurred in females, patients aged between 59 and 69 years, and patients at a lower clinical stage. All MSI GCs had CD8 expression but lacked PD-L1 expression, indicating that MSI was related to CD8 expression but irrelevant to PD-L1 expression. However, there was no significant difference in the expression of CD8/PD-L1 between MSI GC and microsatellite stable (MSS) GC. Kaplan-Meier survival curves revealed that patients with MSI had a significantly longer overall survival (OS) than patients with MSS. CONCLUSIONS: In Chinese GC patients, MSI frequently occurred in females, patients aged between 59 and 69, and patients with lower clinical stages. Patients with MSI-High (MSI-H) and MSI-Low (MSI-L) had a longer OS than patients with MSS. MSI was related to CD8 expression but irrelevant to PD-L1 expression.

Nivolumab for esophageal squamous cell carcinoma and the predictive role of PD-L1 or CD8 expression in its therapeutic effect.

INTRODUCTION: Nivolumab, a programmed death 1 (PD-1) inhibitor, has recently demonstrated efficacy as second-line therapy for esophageal squamous cell carcinoma (ESCC) patients in a phase III trial. We report real-world clinical outcomes of nivolumab therapy for ESCC patients. METHODS: ESCC patients refractory/intolerant to at least one line of chemotherapy and who received nivolumab as a subsequent line of therapy were included. The efficacy and safety of nivolumab and the predictive role of PD-L1 and CD8 expression were analyzed. RESULTS: Fifty-eight patients were analyzed for safety and survival outcomes, while 57 were analyzed for objective response rates (ORR) excluding one with no measurable lesions. Eleven patients achieved a partial response, leading to an ORR of 19.3%. The median response duration was 6.5 months (range 4.1-22.4). The median progression-free survival (PFS) and overall survival were 2.1 (95% confidence interval [CI] 1.8-2.3) and 7.4 (95% CI 4.8-10.0) months, respectively. Among patients with adequate samples, 56.9% (29/51), 27.5% (14/51), and 17.6% (9/51) expressed a combined positive score (CPS) ≥ 1, ≥ 10, and ≥ 20, respectively, while 24.4% (11/45) and 57.5% (23/40) were positive for intratumoral and peritumoral CD8 + T cell infiltration, respectively. A significantly longer PFS was observed in patients with a CPS ≥ 20 (7.5 [95% CI 1.8-13.1] vs. 1.9 [1.4-2.3] months, P = 0.05), and a trend towards better survival was seen in those with CPS ≥ 10 or intratumoral CD8 + T cell infiltration. CONCLUSIONS: Nivolumab is a valuable option at subsequent treatment lines for patients with advanced ESCC.

High PD-1 expression level is associated with an unfavorable prognosis in patients with cervical adenocarcinoma.

PURPOSE: The effectiveness of immunotherapy for cervical adenocarcinoma (CA) has not been demonstrated yet. Programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and CD8 may be used as biomarkers of response to immune therapy in CA patients. In the present study, we aimed to investigate whether the expression levels of PD-1, PD-L1, and CD8 can predict the prognosis of patients with CA and their response to immune checkpoint inhibition therapy. METHODS: In the present study, the clinical stage for all 82 patients with cervical adenocarcinoma was classified according to the guidelines of the International Federation of Gynecology and Obstetrics (FIGO); there were 5, 48, 5, 14, 8, and 2 patients with stage IA, IB, IIA, IIB, IIIB, and IVB disease, respectively. The levels of PD-1, PD-L1, and CD8 were analyzed by the immunohistochemical analysis of the formalin-fixed paraffin-embedded tumor samples. The correlation between the expression levels and patient prognosis was analyzed using the Kaplan-Meier method and univariate and multivariate Cox proportional hazard regression models. RESULTS: We observed a significant inverse correlation between the expression of PD-1 and CD8 (p = 0.001, chi-square test). We also found a significant inverse correlation between the expression of PD-L1 and CD8 (p = 0.027). The overall survival and progression-free survival rates were significantly worse in patients with positive PD-1 expression (p = 0.031; p = 0.087, respectively). CONCLUSION: Our results suggest that a high PD-1 expression is associated with a poor prognosis in patients with CA. Further research is necessary to identify the molecular mechanisms that mediate this association.

Classical Hodgkin Lymphoma With Aberrant CD8 Expression: A Clinicopathologic Study of Five Cases.

Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (CHL) are of B-cell origin. In a small number of CHL cases, the tumor cells can express T-cell antigens. CD8 expression in this setting is extremely rare. We identified 5 cases of CHL with aberrant CD8 expression from our database. The patients included 3 men and 2 women with a median age of 33 years (range = 20-59 years). All the patients initially presented with lymphadenopathy and variable number of RS cells. Two cases were classified as mixed cellularity type that showed prominent vascular proliferation mimicking peripheral T-cell lymphoma. Two cases represented nodular sclerosis type. The tumor cells in all cases were positive for CD8 and negative for CD2, CD3, CD4, and CD7 and carried germline T-cell receptor genes. Molecular studies revealed T-cell receptor genes to be in germline configuration in 4 cases with available information. Given the morphologic overlap with peripheral T-cell lymphoma and the rarity of this type of CHL, identifying more cases will help our better understanding of this entity.

Stromal PD-1/PD-L1 Expression Predicts Outcome in Colon Cancer Patients.

INTRODUCTION: The programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays an important role in controlling immune suppression by down-regulating T effector cell activities, enabling tumor cells to escape from the host's antitumor immunsurveillance. While only a small part of colon cancer cells express PD-L1, we sought to evaluate the differential impact of stromal and epithelial PD-L1 expression of primary tumors and liver metastasis on overall survival (OS) in colon cancer patients. PATIENTS AND METHODS: Using a next-generation tissue microarray approach, we assessed both epithelial and stromal PD-L1 expression levels in primary tumors (n = 279) and corresponding liver metastases (n = 14) of colon cancer patients. PD-L1 positivity was graded according to the percentage (0.1%-1%, > 1%, > 5%, > 50%) of tumor cells with membranous PD-L1 expression or as the percentage of positive stroma cells and associated inflammatory infiltrates. We also assessed the interplay between stromal PD-1/PD-L1 and both intratumoral and stromal CD8 count and their impact on outcome. The primary end point was OS. RESULTS: Stromal PD-L1 and PD-1 expression were both associated with less aggressive tumor behavior in colon cancer patients, which translated into better OS and disease-free survival, respectively. Conversely, PD-L1 staining in the tumor cells was less frequent than stromal staining and was associated with features of aggressive tumor biology, although without impact on outcome. Interestingly, the PD-L1 staining pattern remained similar between primary tumors and corresponding liver metastases. Stromal PD-1 expression correlated significantly with stromal PD-L1 staining and both intratumoral and stromal CD8 expression. CONCLUSION: Stromal PD-1/PD-L1 expression might serve as a prognostic marker in colon cancer patients.

Accentuated hypo- and hyper-NK lymphocyte CD8 expression is a marker of NK subsets' misbalance and is predictive for reproductive failures.

INTRODUCTION: NK cells play critical yet poorly defined role in reproductive processes. Role of CD8αα expression on a part of peripheral blood NK lymphocyte population is not clear. PATIENTS AND METHODS: During isolated double-blinded clinical investigation we studied blood samples from 153 women with multiple reproductive failures undergoing IVF which were drawn 5-12d before embryo transfer procedure. 90 women had IVF failures (IVFf), 24 became pregnant with subsequent pregnancy failure (Pf), 39 became pregnant with subsequent successful pregnancy. During retrospective study we analyzed our laboratory data of 1045 infertile women which underwent routine immunology investigation after IVF failures. Lymphocyte phenotype and NK cytotoxicity was studied by FACScan flow cytometer using BD monoclonal abs. RESULTS: We showed that NK-CD8 expression being increased↑ (>60%) was predictive for IVFf (OR 3.523, p=0.0193, n=23) while being decreased↓ (<40%) was significantly predictive for subsequent Pf (OR 4.571, p=0.0418, n=37). Balanced "conditionally normal" NKCD8 expression (40-60%, n=93) was very significantly predictive for whole reproductive success after IVF (OR 3.972, p=0.0021). Analysing retrospective data, we found decreased CD3- CD56++ and T lymphocyte frequency in both "accentuated" groups compared to patients with "conditionally normal" NK-CD8 expression (n=562). NK-CD8 expression↓ (n=341) was associated with elevated HLADR expression on NK, CD3+, CD3+ CD8+, CD3+ CD4+ cells. Meanwhile, NK-CD8 expression ↑ (n=142) was associated with elevated NK frequency, NK cytotoxicity levels and CD158a expression on NK cells, simultaneously with decreased CD3CD8 and CD3+ CD56+ numbers. CONCLUSION: Both hypo- and hyper-NK lymphocyte CD8 expression "accentuations" associated with NK subsets' misbalance (NK and T lymphocyte phenotype and cytotoxicity). Both hypo- and hyper-NK lymphocyte CD8 expression "accentuations" associated with poor IVF outcome, possibly through their association with other unfavorable accentuated parameters that result into unfavorable combination of "accentuated phenotype".

IL-4 and IL-13 mediated down-regulation of CD8 expression levels can dampen anti-viral CD8⁺ T cell avidity following HIV-1 recombinant pox viral vaccination.

We have shown that mucosal HIV-1 recombinant pox viral vaccination can induce high, avidity HIV-specific CD8(+) T cells with reduced interleukin (IL)-4 and IL-13 expression compared to, systemic vaccine delivery. In the current study how these cytokines act to regulate anti-viral CD8(+) T, cell avidity following HIV-1 recombinant pox viral prime-boost vaccination was investigated. Out of a panel of T cell avidity markers tested, only CD8 expression levels were found to be enhanced on, KdGag197-205 (HIV)-specific CD8(+) T cells obtained from IL-13(-/-), IL-4(-/-) and signal transducer and, activator of transcription of 6 (STAT6)(-/-) mice compared to wild-type (WT) controls following, vaccination. Elevated CD8 expression levels in this instance also correlated with polyfunctionality, (interferon (IFN)-γ, tumour necorsis factor (TNF)-α and IL-2 production) and the avidity of HIVspecific CD8(+) T cells. Furthermore, mucosal vaccination and vaccination with the novel adjuvanted IL-13 inhibitor (i.e. IL-13Rα2) vaccines significantly enhanced CD8 expression levels on HIV-specific CD8(+), T cells, which correlated with avidity. Using anti-CD8 antibodies that blocked CD8 availability on CD8(+), T cells, it was established that CD8 played an important role in increasing HIV-specific CD8(+) T cell avidity and polyfunctionality in IL-4(-/-), IL-13(-/-) and STAT6(-/-) mice compared to WT controls, following vaccination. Collectively, our data demonstrate that IL-4 and IL-13 dampen CD8 expression levels on anti-viral CD8(+) T cells, which can down-regulate anti-viral CD8(+) T cell avidity and, polyfunctionality following HIV-1 recombinant pox viral vaccination. These findings can be exploited to, design more efficacious vaccines not only against HIV-1, but many chronic infections where high, avidity CD8(+) T cells help protection.