Immune suppression in premalignant respiratory papillomas: enriched functional CD4+Foxp3+ regulatory T cells and PD-1/PD-L1/L2 expression

Quantification and Functional Studies of Neutrophilic Cells Identifies Distinct Papilloma Phenotypes

OBJECTIVES

To characterize the distribution of immune cell subsets within laryngeal papillomas and to study the function of potentially immunosuppressive neutrophilic and regulatory T cells (Tregs).

METHODS

Fresh clinical papilloma specimens were collected at the time of surgery and studied with multiparameter flow cytometry. Papilloma infiltrating neutrophilic cells and Tregs were sorted and studied functionally with ex vivo T cell suppression assays.

RESULTS

Flow cytometric analysis of fresh laryngeal papillomas samples from 18 adult patients with recurrent respiratory papillomatosis revealed patterns in immune constituency between patients. Clearly divergent phenotypes based primarily on the degree of neutrophilic and T cell infiltration were identified. Relative neutrophilic cell enrichment and T cell depletion were observed in 50% of samples and neutrophilic cell depletion and T cell enrichment were observed in the others. Greater papilloma neutrophilic cell enrichment was positively associated with the number of clinically indicated interventions required in the 12 months prior to sample collection, linking papilloma neutrophil inflammation to disease severity. Functional assays revealed the ability of both papilloma infiltrating neutrophilic and Tregs to suppress T cell function at roughly equal magnitudes, but substantially increased infiltration of neutrophilic cells compared to Tregs across samples.

CONCLUSION

Neutrophilic cells are an important contributor to immunosuppression within the respiratory papilloma microenvironment. Given these data and the association between greater neutrophilic cell infiltration and lack of clinical response to therapeutic vaccination, additional study of strategies aimed at limiting neutrophilic cell infiltration or function within papillomas is warranted.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3238-3244, 2024.

Profiling of VEGF Receptors and Immune Checkpoints in Recurrent Respiratory Papillomatosis

OBJECTIVES

Recurrent respiratory papillomatosis (RRP) is caused by human papilloma virus (HPV) infection of the aerodigestive tract that significantly impacts quality-of-life including the ability to communicate and breathe. Treatment was traditionally limited to serial ablative procedures in the O.R. with possible local adjuvant therapy, but new systemic therapies, such as Vascular endothelial growth factor (VEGF) inhibitors, are showing significant promise. This study aims to determine whether rationale exists for combination therapeutic approaches using VEGF inhibitors and/or immune checkpoint blockade.

METHODS

Using fresh specimens from the O.R., we performed flow cytometry on papilloma, normal adjacent tissue, and blood. Papilloma and surrounding tissue were examined for expression of PD-L1, PD-L2, Galectin-9, VEGFR2, and VEGFR3. CD8+ and CD4+ T cells were assayed for expression of PD-1, TIGIT, LAG3, and TIM3.

RESULTS

Our data shows that papilloma tissue exhibits significantly higher levels of PD-L1 and PD-L2 compared to adjacent tissue. Elevated levels of the VEGF receptor VEGFR3 were also observed in papilloma tissue. When examining T cells within the papilloma, elevated PD-1 and TIGIT expression was observed on CD8+ T cells, while levels of PD-1, TIGIT, and TIM3 were elevated on CD4+ T cells compared to PBMCs. Heterogenous marker expression was observed between individuals.

CONCLUSIONS

Our analysis shows that RRP tissue shows elevated levels of multiple immune check point targets and VEGFR3, with varied patterns unique to each papilloma patient. Some of these immune checkpoint markers already have novel immunotherapies available or in development, providing molecular rationale to offer these systemic treatments to selected patients affected by RRP alongside VEGF inhibitors. Laryngoscope, 134:2819-2825, 2024.

Preclinical development and clinical studies of targeted JAK/STAT combined Anti-PD-1/PD-L1 therapy

Programmed cell death protein 1 (PD-1) binds to its ligand to help tumours evade the immune system and promote tumour progression. Although anti-PD-1/PD-L1 therapies show powerful effects in some patients, most patients are unable to benefit from this treatment due to treatment resistance. Therefore, it is important to overcome tumour resistance to PD-1/PD-L1 blockade. There is substantial evidence suggesting that the JAK/STAT signalling pathway plays a significant role in PD-1/PD-L1 expression and anti-PD-1/PD-L1 treatment. Herein, we describe the effects of the JAK/STAT signalling pathway on PD-1/PD-L1. Subsequently, the relationship between molecular mutations in the JAK/STAT signalling pathway and immune resistance was analysed. Finally, the latest advancements in drugs targeting the JAK/STAT pathway combined with PD1/PD-L1 inhibitors are summarised.

Inflammation-Driven Nanohitchhiker Enhances Postoperative Immunotherapy by Alleviating Prostaglandin E2-Mediated Immunosuppression

Inflammation contributes to the immunosuppressive microenvironment and leads to the recurrence of surgically resected tumors. The COX-2/PGE2 axis is considered a key player in shaping the immunosuppression microenvironment. However, targeted modulation of the postoperative tumor microenvironment is challenging. To specifically curb the inflammation and alleviate immunosuppression, here, we developed a PGE2 inhibitor celecoxib (CXB)-loaded bionic nanoparticle (CP@CM) coated with activated murine vascular endothelial cell (C166 cells) membrane to target postoperative melanoma and inhibit its recurrence. CP@CM adhered to inflammatory white blood cells (WBCs) through the adhesion molecules, including ICAM-1, VCAM-1, E-selectin, and P-selection, expressed on the surface of C166 cells. Leveraging the natural tropism of the WBC to the inflammatory postoperative tumor site, CP@CM efficiently targeted postoperative tumors. In melanoma postoperative recurrence models, CXB significantly reduced PGE2 secretion and the recruitment of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Treg) by inhibiting the activity of COX-2. This was followed by an increase in the infiltration of CD8+ T cells and CD4+ T cells in tumor tissues. Additionally, the immune responses were further enhanced by combining a PD-L1 monoclonal antibody. Ultimately, this immunotherapeutic strategy reversed the tumor immunosuppressive microenvironment and inhibited tumor recurrence, demonstrating a promising potential for postoperative immunotherapy for melanoma.

Prevalence of viral DNA in high-grade serous epithelial ovarian cancer and correlation with clinical outcomes

INTRODUCTION

Currently 11 infectious agents are classified as carcinogenic but the role of infectious agents on outcomes of epithelial ovarian cancer is largely unknown.

OBJECTIVE

To explore the association between infectious agents and ovarian cancer, we investigated the prevalence of viral DNA in primary ovarian cancer tumors and its association with clinical outcomes.

METHODS

Archived tumors from 98 patients diagnosed with high-grade serous epithelial ovarian cancer were collected between 1/1/1994 and 12/31/2010. After DNA extraction, Luminex technology was utilized to identify polymerase chain reaction-amplified viral DNA for 113 specific viruses. Demographic data and disease characteristics were summarized using descriptive statistics. We used logistic regression and Cox proportional hazards model to assess associations between tumor viral status and disease outcome and between tumor viral presence and overall survival (OS), respectively.

RESULTS

Forty-six cases (45.9%) contained at least one virus. Six highly prevalent viruses were associated with clinical outcomes and considered viruses of interest (VOI; Epstein-Barr virus 1, Merkel cell polyomavirus, human herpes virus 6b, and human papillomaviruses 4, 16, and 23). Factors independently associated with OS were presence of VOI (HR 4.11, P = 0.0001) and platinum sensitivity (HR 0.21, P<0.0001). Median OS was significantly decreased when tumors showed VOI versus not having these viruses (22 vs 44 months, P<0.0001). Women <70 year old with VOI in tumors had significantly lower median OS versus age-matched women without VOI (20 vs 57 months, P = 0.0006); however, among women ≥70 years old, there was no difference in OS by tumor virus status.

CONCLUSIONS

The presence of a VOI was significantly associated with a lower OS. These findings may have implications for clinical management of ovarian cancer but require additional studies.

In vivo transfection of cytokine genes into tumor cells using a synthetic vehicle promotes antitumor immune responses in a visceral tumor model

The tumor microenvironment (TME) strongly affects the clinical outcomes of immunotherapy. This study aimed to activate the antitumor immune response by manipulating the TME by transfecting genes encoding relevant cytokines into tumor cells using a synthetic vehicle, which is designed to target tumor cells and promote the expression of transfected genes. Lung tumors were formed by injecting CT26.WT intravenously into BALB/c mice. Upon intravenous injection of the green fluorescent protein-coding plasmid encapsulated in the vehicle, 14.2% tumor-specific expression was observed. Transfection of the granulocyte-macrophage colony-stimulating factor (GM-CSF) and CD40 ligand (L)-plasmid combination and interferon gamma (IFNγ) and CD40L-plasmid combination showed 45.5% and 54.5% complete remission (CR), respectively, on day 60; alternate treatments with both the plasmid combinations elicited 66.7% CR, while the control animals died within 48 days. Immune status analysis revealed that the density of dendritic cells significantly increased in tumors, particularly after GM-CSF- and CD40L-gene transfection, while that of regulatory T cells significantly decreased. The proportion of activated killer cells and antitumoral macrophages significantly increased, specifically after IFNγ and CD40L transfection. Furthermore, the level of the immune escape molecule programmed death ligand-1 decreased in tumors after transfecting these cytokine genes. As a result, tumor cell-specific transfection of these cytokine genes by the synthetic vehicle significantly promotes antitumor immune responses in the TME, a key aim for visceral tumor therapy.

Influence of PD-1/PD-L1 on immune microenvironment in oral leukoplakia and oral squamous cell carcinoma

OBJECTIVE

To evaluate the relation between the expression of PD-1, PD-L1, CD3, CD8, Foxp3 and clinicopathological features in patients with oral leukoplakia (OLK) and oral squamous cell carcinomas (OSCC) as well as the malignant outcome in OLK patients, and to study the effect of PD-1 and PD-L1 on immune microenvironment in the progression of oral carcinogenesis.

METHODS

We evaluated the expression of PD-1/PD-L1 and composition of CD3+ , CD8+ and Foxp3+ T lymphocytes in OLK and OSCC samples by immunohistochemical (IHC) staining and analyzed their relation with clinical information and malignant transformation in OLK patients.

RESULTS

IHC staining demonstrated that the expression of PD-1 was significantly increased in the high-grade OLK group than in the low-grade OLK group, while PD-L1 was detected mainly in OSCC. The expression of CD3, CD8, and Foxp3 was found higher in the high-grade OLK group than in the low-grade OLK group, and the Foxp3+ cells were found more in the OSCC group than in the high-grade OLK group. PD-1 was significantly correlated with CD3 (p < 0.05, R = 0.52), CD8 (p < 0.05, R = 0.46), and Foxp3 (p < 0.05, R = 0.46), and the low PD-1-expression group showed a better malignant-free survival than high PD-1 expression group in the OLK (p < 0.05).

CONCLUSION

The PD-1/PD-L1 may induce immune suppression in OLK and accelerate the progress of malignant transformation.

Stabilization of Recurrent Respiratory Papillomatosis with Pembrolizumab Therapy: A Case Report

Recurrent respiratory papillomatosis (RRP) is a benign neoplastic disease of the respiratory tract that is caused by human papilloma virus (HPV). The current standard of care is surgical excision with adjuvant treatment as needed. Multiple adjuvant treatments have been used with some success, but long-term control of disease remains difficult. We report on a case of a patient with a long history of RRP who had stabilized true vocal fold disease while on pembrolizumab for concurrent early stage lung squamous cell carcinoma.

Efficacy and Safety of Low-Dose Apatinib Combined with Chemotherapy as Second-Line Treatment for Advanced Gastric Cancer: A Meta-Analysis

INTRODUCTION

At present, there are several studies on low-dose apatinib combined with chemotherapy as a second-line treatment of advanced gastric cancer (AGC), but the conclusions are controversial. Therefore, this meta-analysis aimed to evaluate the efficacy and safety of low-dose apatinib combined with chemotherapy as a second-line treatment of AGC.

METHODS

Nine databases were searched for records on apatinib combined with chemotherapy in treating AGC from inception to June 2022. The observation group received low-dose apatinib combined with chemotherapy, while the controls received chemotherapy alone or other non-placebo treatments. Outcomes included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and adverse events. The relative risk (RR) and weighted mean difference (WMD) were used as effect sizes.

RESULTS

Eight studies involving 679 patients were included in this meta-analysis. The results of the meta-analysis showed that the observation group was superior to the controls in terms of ORR (RR = 1.38, 95% confidence interval [CI]: 1.05-1.81, p = 0.02), DCR (RR = 1.35, 95% CI: 1.20-1.53, p < 0.001), OS (WMD = 4.72, 95% CI: 0.71-8.72, p < 0.001), and PFS (WMD = 2.67, 95% CI: 1.7-3.63, p < 0.001). There were no significant differences between the two groups in adverse events of any grade except hypertension (RR = 2.82, 95% CI: 2.07-3.84, p < 0.001), hand-mouth syndrome (RR = 1.84, 95% CI: 1.84-2.48, p < 0.001), and proteinuria (RR = 3.63, 95% CI: 2.31-5.7, p < 0.001).

CONCLUSION

Low-dose apatinib combined with chemotherapy as a second-line therapy is more effective in improving the efficacy of AGC compared to chemotherapy alone. However, this option has the potential to increase the risk of hypertension, hand-mouth syndrome, and proteinuria.

Clinical correlation analysis of HPV infection in adult laryngeal papilloma and adverse events

OBJECT

To explore the factors affecting dysplasia and carcinogenesis in adult patients with laryngeal papilloma, and the clinical differences between human papillomavirus (HPV)-positive and HPV-negative patients.

METHODS

Clinical data of 80 adult patients with laryngeal papilloma and associated adverse events were collected retrospectively. They had undergone surgery in the Department of Otolaryngology Head and Neck, Beijing Tongren Hospital, Capital Medical University between January 2010 and December 2020. HPV infection was detected using RNA in situ hybridization.

RESULTS

Regression analysis showed that multiple lesions and high Ki-67 expression were independent factors affecting the occurrence of adverse events. Differences between the HPV-positive and HPV-negative groups were compared. The age and Ki-67 expression in the HPV-negative group were significantly higher than those in the HPV-positive group. In the severe dysplasia to carcinogenesis subgroup, the proportion of HPV-negative patients was significantly higher than that in the mild to moderate dysplasia subgroup. There was a high correlation between positive p16 immunohistochemistry (IHC) and positive HPV.

CONCLUSIONS

Multiple lesions and high Ki-67 expression are independent factors that are linked with adverse laryngeal papilloma progression. Elderly HPV-negative patients are at an increased risk of severe dysplasia and carcinogenesis. Positive p16 IHC was very accurate in detecting HPV infection.

Molecular Mechanisms of Carcinogenesis in Pediatric Airways Tumors

Primary tumors of the airways in the pediatric population are very rare entities. For this reason, little is known about the pathogenesis of these neoplasms. Understanding the biology has different practical implications: for example, it could help in the differential diagnosis, have a prognostic significance, or may lead to the development of a targeted therapy. The aim of this article is to present the current knowledge about pediatric airways tumors, focusing on the molecular mechanisms that cause the onset and progression of these neoplasms. After a brief introduction of epidemiology and clinical presentation, the tumorigenesis of the most frequent pediatric airways tumors will be described: Juvenile-onset recurrent respiratory papillomatosis (JORRP), Subglottic Hemangiona (SH), Rhabdomyosarcoma (RMS), and Mucoepidermoid carcinoma (MEC).

PGE2 expression by HPV6/11-induced respiratory papillomas blocks NK cell activation in patients with recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP), a rare chronic disease caused primarily by human papillomavirus types 6 and 11, consists of repeated growth of premalignant papillomas in the airway. RRP is characterized by multiple abnormalities in innate and adaptive immunity. Natural killer (NK) cells play important roles in immune surveillance and are part of the innate immune responses that help prevent tumor growth. We identified that papillomas lack classical class I MHC and retain nonclassical class I MHC expression. Moreover, in this study, we have identified and characterized the mechanism that blocks NK cell targeting of papilloma cells. Here, we show for the first time that the PGE₂ secreted by papilloma cells directly inhibits NK cells activation/degranulation principally through the PGE₂ receptor EP2, and to a lesser extent through EP4 signaling. Thus, papilloma cells have a potent mechanism to block NK cell function that likely supports papilloma cell growth.

Prospective, Multi-Center Study of the Anatomic Distribution of Recurrent Respiratory Papillomatosis

OBJECTIVES/HYPOTHESIS

To create a model of the anatomic distribution, recurrence, and growth patterns of recurrent respiratory papillomatosis (RRP).

STUDY DESIGN

Prospective, multi-institutional cohort study.

METHODS

Adult patients with a diagnosis of RRP evaluated between August 1, 2018 and February 1, 2021 at six participating centers were invited to enroll. At each office or operating room encounter, laryngologists recorded the location and size of RRP lesions using a 22-region schematic. A generalized linear mixed effects model was used to compare region variations in lesion prevalence and recurrence.

RESULTS

The cohort comprised 121 patients: 74% were male, 81% had been diagnosed with adult-onset RRP, and a plurality (34%) had undergone 0 to 3 RRP interventions prior to enrollment. Across the study period, the odds of a lesion occurring in the glottis was significantly higher (odds ratio [OR]: 26.51; 95% confidence interval [CI]: 11.76-59.75, P < .001) compared with all other areas of the larynx and trachea. Within the true vocal folds, the membranous vocal folds had significantly higher odds (OR: 6.16; 95% CI: 2.66-14.30, P < .001) of lesion occurrence compared to the cartilaginous vocal folds. Despite these strong trends in lesion distribution, there were no differences in the odds of lesion recurrence, growth, or in the time to recurrence, between anatomic subsites.

CONCLUSIONS

RRP lesions are most likely to occur in the glottis, particularly the membranous vocal folds, compared with other regions of the larynx or trachea. However, all lesions demonstrate similar behavior with respect to recurrence, growth, and time to recurrence regardless of anatomic location.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2403-2411, 2022.

Restricted Recruitment of NK Cells with Impaired Function Is Caused by HPV-Driven Immunosuppressive Microenvironment of Papillomas in Aggressive Juvenile-Onset Recurrent Respiratory Papillomatosis Patients

Laryngopharynx epithelium neoplasia induced by HPV6/11 infection in juvenile-onset recurrent respiratory papillomatosis (JO-RRP) causes a great health issue characteristic of frequent relapse and aggressive disease progression. Local cell-mediated immunity shaped by the recruitment and activation of cytotoxic effector cells is critical for viral clearance. In this study, we found that NK cells in the papillomas of aggressive JO-RRP patients, in contrast to massive infiltrated T cells, were scarce in number and impaired in activation and cytotoxicity as they were in peripheral blood. Data from cell infiltration analysis indicated that the migration of NK cell to papilloma was restricted in aggressive JO-RRP patients. Further study showed that the skewed chemokine expression in the papillomas and elevated ICAM-1 expression in hyperplastic epithelia cells favored the T cell but not NK cell recruitment in aggressive JO-RRP patients. In parallel to the increased CD3⁺ T cells, we observed a dramatical increase in Tregs and Treg-promoting cytokines such as IL-4, IL-10 and TGFβ in papillomas of aggressive JO-RRP patients. Our study suggested that likely initialized by the intrinsic change in neoplastic epithelial cells with persistent HPV infection, the aggressive papillomas built an entry barrier for NK cell infiltration and formed an immunosuppressive clump to fend off the immune attack from intra-papillomas NK cells. IMPORTANCE Frequent relapse and aggressive disease progression of juvenile-onset recurrent respiratory papillomatosis (JO-RRP) pose a great challenge to the complete remission of HPV 6/11 related laryngeal neoplasia. Local immune responses in papillomas are more relevant to the disease control considering the locale infected restriction of HPV virus in epitheliums. In our study, the restricted NK cell number and reduced expression of activating NKp30 receptor suggested one possible mechanism underlying impaired NK cell defense ability in aggressive JO-RRP papillomas. Meanwhile, the negative impact of HPV persistent infection on NK cell number and function represented yet another example of a chronic pathogen subverting NK cell behavior, affirming a potentially important role for NK cells in viral containment. Further, the skewed chemokine/cytokine expression in the papillomas and the elevated adhesion molecules expression in hyperplastic epithelia cells provided important clues for understanding blocked infiltration and antiviral dysfunction of NK cells in papilloma.

Prognostic value of PD-1, PD-L1 and PD-L2 deserves attention in head and neck cancer

Head and neck cancer has high heterogeneity with poor prognosis, and emerging researches have been focusing on the prognostic markers of head and neck cancer. PD-L1 expression is an important basis for strategies of immunosuppressive treatment, but whether it has prognostic value is still controversial. Although meta-analysis on PD-L1 expression versus head and neck cancer prognosis has been performed, the conclusions are controversial. Since PD-L1 and PD-L2 are two receptors for PD-1, here we summarize and analyze the different prognostic values of PD-1, PD-L1, and PD-L2 in head and neck cancer in the context of different cell types, tissue localization and protein forms. We propose that for head and neck cancer, the risk warning value of PD-1/PD-L1 expression in precancerous lesions is worthy of attention, and the prognostic value of PD-L1 expression at different subcellular levels as well as the judgment convenience of prognostic value of PD-1, PD-L1, PD-L2 should be fully considered. The PD-L1 evaluation systems established based on immune checkpoint inhibitors (ICIs) are not fully suitable for the evaluation of PD-L1 prognosis in head and neck cancer. It is necessary to establish a new PD-L1 evaluation system based on the prognosis for further explorations. The prognostic value of PD-L1, PD-L2 expression in head and neck cancer may be different for early-stage and late-stage samples, and further stratification is required.

Intratumoral IL-28B Gene Delivery Elicits Antitumor Effects by Remodeling of the Tumor Microenvironment in H22-Bearing Mice

IL-28B, belonging to type III interferons (IFN-λs), exhibits a potent antitumor activity with reduced regulated T cells (Tregs) population, yet the effect of IL-28B on the tumor microenvironment (TME) and if IL-28B can downregulate Tregs directly in vitro are still unknown. In this study, we investigated the effects of IL-28B on Tregs in the spleen and TME in H22 tumor-bearing mice and verified the downregulation of IL-28B on Tregs in vitro. We found that rAd-mIL-28B significantly inhibited tumor growth and reduced the frequency of splenic CD4⁺Foxp3⁺ T cells. The levels of CXCL13, ICAM-1, MCP-5, and IL-7 in the serum, and the levels of IL-15 and sFasL in the tumor tissue decreased significantly after rAd-mIL-28B treatment relative to rAd-EGFP. Furthermore, the percentage of CD8⁺ cells in the TME was significantly increased in the rAd-mIL-28B group compared with the untreated group. In vitro, splenocytes were stimulated with anti-CD3/CD28 and IL-2 in the presence of TGF-β with or without IL-28B for three days and followed by flow cytometric, RT-PCR, and IL-10 production analysis. The results showed that IL-28B significantly reduced the proportion of induced Foxp3⁺ cells. It demonstrated that IL-28B may be used as a promising immunotherapy strategy against cancer.

Tumor associated antigen PRAME exhibits dualistic functions that are targetable in diffuse large B-cell lymphoma

PRAME is a prominent member of the cancer testis antigen family of proteins, which triggers autologous T cell–mediated immune responses. Integrative genomic analysis in diffuse large B cell lymphoma (DLBCL) uncovered recurrent and highly focal deletions of 22q11.22, including the PRAME gene, which were associated with poor outcome. PRAME-deleted tumors showed cytotoxic T cell immune escape and were associated with cold tumor microenvironments. In addition, PRAME downmodulation was strongly associated with somatic EZH2 Y641 mutations in DLBCL. In turn, PRC2-regulated genes were repressed in isogenic PRAME-KO lymphoma cell lines, and PRAME was found to directly interact with EZH2 as a negative regulator. EZH2 inhibition with EPZ-6438 abrogated these extrinsic and intrinsic effects, leading to PRAME expression and microenvironment restoration in vivo. Our data highlight multiple functions of PRAME during lymphomagenesis and provide a preclinical rationale for synergistic therapies combining epigenetic reprogramming with PRAME-targeted therapies.

A review of the risk factors associated with juvenile-onset recurrent respiratory papillomatosis: genetic, immune and clinical aspects

BACKGROUND

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is one of the most common benign lesions of hyperplastic respiratory epithelial tissue in children and is predominantly caused by human papillomaviruses (HPVs) 6 and 11. The clinical course of the disease is variable, and some patients even develop a malignancy. The purpose of this review was to summarize the related factors affecting the disease course in patients with JoRRP.

DATA SOURCES

We used databases, including PubMed and Google Scholar, to search for publications on factors associated with the genetic, immune, and clinical aspects of JoRRP. The most relevant articles to the scope of this review were chosen for analysis.

RESULTS

Mother-to-child transmission is the most important mode of disease transmission; other factors, such as immune condition or genetic susceptibility, may be important determinants of JoRRP occurrence. Genetically, the presence of DRB1*0301 and HPV 6/11 E6/E7 is associated with a more severe disease. Immunewise, patients have an enhanced T helper 2-like response. In addition, regulatory T cells are enriched in tumors and may become one of the effective prognostic indicators. For clinical characteristics, patients infected with HPV-11 have more aggressive disease. However, compared with HPV type, age at first onset is a more important factor related to the aggressiveness of JoRRP. Furthermore, socioeconomic status may also affect the course.

CONCLUSIONS

Genetic, immune, and some clinical factors have been noted to play an important role in the course of JoRRP. Exploring definite influencing factors will be an important direction of research in the future.

PD-L1: Can it be a biomarker for the prognosis or a promising therapeutic target in cervical cancer?

Cervical cancer is one of the most common in the female genital tract and remains a leading cause that threatens the health and lives of women worldwide, although preventive vaccines and early diagnosis have reduced mortality. While treatment by operation and chemoradiotherapy for early-stage patients achieve good outcomes, the great majority of cervical cancers caused by the human papilloma virus (HPV) make immunotherapy realizable for patients with advanced and recurrent cervical cancer. To date, some clinical trials of checkpoint immunotherapy in cervical cancer have indicated significant benefits of programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) inhibitors, providing strong evidence for PD-1/PD-L1 as a therapeutic target. In this review article, we discuss the role of PD-L1 and the application of PD-L1 inhibitors in cervical cancer, with the aim of providing direction for future research.

Cutibacterium acnes Induces the Expression of Immunosuppressive Genes in Macrophages and is Associated with an Increase of Regulatory T-Cells in Prostate Cancer

Tumors and infectious agents both benefit from an immunosuppressive environment. Cutibacterium acnes (C. acnes) is a bacterium in the normal skin microbiota, which has the ability to survive intracellularly in macrophages and is significantly more common in prostate cancer tissue compared with normal prostate tissue. This study investigated if prostate cancer tissue culture positive for C. acnes has a higher infiltration of regulatory T-cells (Tregs) and if macrophages stimulated with C. acnes induced the expression of immunosuppressive genes that could be linked to an increase of Tregs in prostate cancer. Real-time PCR and enzyme-linked immunosorbent spot assay (ELISA) were used to examine the expression of immunosuppressive genes in human macrophages stimulated in vitro with C. acnes, and associations between the presence of C. acnes and infiltration of Tregs were investigated by statistically analyzing data generated in two previous studies. The in vitro results demonstrated that macrophages stimulated with C. acnes significantly increased their expression of PD-L1, CCL17, and CCL18 mRNA and protein (p <0.05). In the cohort, Tregs in tumor stroma and tumor epithelia were positively associated with the presence of C. acnes (P = 0.0004 and P = 0.046, respectively). Since the macrophages stimulated with C. acnes in vitro increased the expression of immunosuppressive genes, and prostate cancer patients with prostatic C. acnes infection had higher infiltration of Tregs than their noninfected counterparts, we suggest that C. acnes may contribute to an immunosuppressive tumor environment that is vital for prostate cancer progression. IMPORTANCE In an immune suppressive tumor microenvironment constituted by immunosuppressive cells and immunosuppressive mediators, tumors may improve their ability to give rise to a clinically relevant cancer. In the present study, we found that C. acnes might contribute to an immunosuppressive environment by recruiting Tregs and by increasing the expression of immunosuppressive mediators such as PD-L1, CCL17, and CCL18. We believe that our data add support to the hypothesis of a contributing role of C. acnes in prostate cancer development. If established that C. acnes stimulates prostate cancer progression it may open up avenues for targeted prostate cancer treatment.

Rational administration sequencing of immunochemotherapy elicits powerful anti-tumor effect

As a research hotspot, immune checkpoint inhibitors (ICIs) is often combined with other therapeutics in order to exert better clinical efficacy. To date, extensive laboratory and clinical investigations into the combination of ICIs and chemotherapy have been carried out, demonstrating augmented effectiveness and broad application prospects in anti-tumor therapy. However, the administration of these two treatment modalities is usually randomized or fixed to a given chronological order. Nevertheless, the pharmacological effect of drug is closely related to its exposure behavior in vivo, which may consequently affect the synergistic outcomes of a combined therapy. In this study, we prepared a lipid nanoparticle encapsulating docetaxel (DTX-VNS), and associated it with the immune checkpoint inhibitor anti-PD-1 antibody (αPD-1) for the treatment of malignant tumors. To identify the optimum timing and sequencing for chemotherapy and immunotherapy, we designed three administration regimes, including the simultaneous delivery of DTX-VNS and αPD-1(DTX-VNS@αPD-1), DTX-VNS delivery before (DTX-VNS plus αPD-1) or post (αPD-1 plus DTX-VNS) PD-1 blockade with an interval of two days. Analysis from mass spectrometry, multi-factor detection and other techniques indicated that DTX-VNS plus αPD-1 initiated a powerful anti-tumor response in multiple tumor models, contributing to a remarkably reshaped tumor microenvironment landscape, which may attribute to the maximum therapeutic additive effects arise from a concomitant exposure of DTX-VNS and αPD-1 at the tumor site. By profiling the exposure kinetics of nanoparticles and αPD-1 in vivo, we defined the administration schedule with utmost therapeutic benefits, which may provide a valuable clinical reference for the rational administration of immunochemotherapy.

Sequential administration of pemetrexed and cisplatin reprograms tumor immune microenvironment and potentiates PD-1/PD-L1 treatment in a lung cancer model

This article aimed to investigate the effects of the administration method of pemetrexed and cisplatin on the efficacy and safety of treating non-small cell lung cancer (NSCLC) and the intrinsic molecular mechanism. Subcutaneous injection of A549 cells into BALB/C nude mice was used to explore the efficacy of different administration methods of pemetrexed and cisplatin in vivo. Immunogenic cell death (ICD) was evaluated by ATP secretion, ecto-CALR expression, and high mobility group protein 1 release. Western blot, qRT-PCR, and immunohistochemical staining were applied to detect the expression of apoptosis, cell cycle, and stimulator of interferon genes (STING) pathway-related markers. Immune microenvironment was evaluated by secretion of cytokines, infiltration of CD8⁺ T cells, and expression of programmed death molecular ligand-1 (PD-L1). Sequential treatment with pemetrexed and cisplatin inhibited A549 cell-driven tumor formation in nude mice and regulated the expression of apoptosis and cell cycle-related genes. STING pathway and ICD were further activated by sequential treatment with pemetrexed and cisplatin. This sequential administration method increased the levels of interferon β, tumor necrosis factor α, interleukin 12, and C-X-C motif chemokine ligand 10, enhanced the infiltration of CD8⁺ T cells, and upregulated the expression of PD-L1. Sequential administration of pemetrexed and cisplatin in the treatment of mouse NSCLC model may have a better effect than combination of drugs, providing theoretical basis and potential guidance for clinical medication.

Potential role of immune cell genetic variants associated with tumor microenvironment response in laryngeal squamous cell carcinoma (LSCC) in terms of clinicopathological features

Immunomodulatory signals regulate the self-tolerance, activation, priming and survival processes of T cells. Programmed cell death protein 1 (PD1), Programmed death-ligand 1 (PD-L1) inhibitory signals and CD27, CD28 costimulators have been detected for many solid organ cancers in tumor-infiltrating T cells. It was aimed to investigate the immune cell-based regulatory genetic variants in laryngeal squamous cell carcinoma (LSCC) in terms of clinicopathological features. Genotyping was performed by PCR-RFLP method for PD-1 rs2227981, PD-L1 rs2890658, CD28 rs3116496, CD27 rs2267966 genetic variants from genomic DNAs extracted from peripheral blood samples in One Hundred Thirty-Six individuals (Sixty-one LSCC and seventy-five controls). Analysis of SNPs was carried out according to multiple inheritance models (co-dominant, dominant, recessive, over-dominant and log-additive). There was no difference between LSCC and control groups in genotype/allele distribution for PD-1 and PD-L1 (p > 0.05). In the PD-1 overdominant model, the CT genotype was found to be high (p = 0.036) in those without a family history. The frequency of C allele (AC+CC) in the PD-L1 dominant model was higher in alcohol users and those with reflux (p = 0.024; p = 0.001 respectively). In the Dominant model for PD-L1, the AA genotype was lower in moderately and well-differentiated tumors than in poorly differentiated tumors (p = 0.02). CD27 AT and CD28 CT genotypes were found to be higher in LSCC patients compared to the control group (p = 0.009; p = 0.01 respectively), while linkage disequilibrium (LD) was detected between CD27 and CD28 (p = 0.02). In the CD28 dominant model, C allele (CT+CC) carriage was found to be high in those with family history and in those without reflux and perineural invasion (p = 0.01; p = 0.01; p = 0.03 respectively). In LSCC, PD-L1 rather than PD-1 has a prognostic effect in terms of clinicopathology, and the LD and clinicopathological relationships detected between CD28 and CD27 genotypes suggest that the hereditary immune checkpoint-dependent T cell traffic may be pathophysiologically important.

Microenvironmental modulation of the developing tumour: an immune-stromal dialogue

Successful establishment of a tumour relies on a cascade of interactions between cancer cells and stromal cells within an evolving microenvironment. Both immune and nonimmune cellular components are key factors in this process, and the individual players may change their role from tumour elimination to tumour promotion as the microenvironment develops. While the tumour-stroma crosstalk present in an established tumour is well-studied, aspects in the early tumour or premalignant microenvironment have received less attention. This is in part due to the challenges in studying this process in the clinic or in mouse models. Here, we review the key anti- and pro-tumour factors in the early microenvironment and discuss how understanding this process may be exploited in the clinic.

Impact of tumor programmed death ligand-1 expression on osimertinib efficacy in untreated EGFR-mutated advanced non-small cell lung cancer: a prospective observational study

Background

Osimertinib monotherapy is currently the standard of care as a first-line treatment for patients harboring epidermal growth factor receptor (EGFR) mutations; however, some EGFR-mutated non-small cell lung cancer (NSCLC) patients exhibit primary resistance and an insufficient response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Elevated programmed death-ligand 1 (PD-L1) expression in tumors was reported as a negative predictive factor for outcomes of first- or second-generation EGFR-TKIs.

Methods

We prospectively assessed advanced NSCLC patients with EGFR mutations who were treated with osimertinib at 14 institutions in Japan between September 2019 and December 2020. Relationships between outcomes of osimertinib monotherapy and patients’ characteristics were reviewed.

Results

Seventy-one patients who underwent the tumor PD-L1 test were enrolled. Multivariate analysis identified tumor PD-L1 expression as an independent predictor for progression-free survival (PFS) with osimertinib treatment (P=0.029). The objective-response and disease-control rates for osimertinib treatment were significantly lower in patients demonstrating elevated PD-L1 levels relative to those with low or negative PD-L1 level (P=0.043 and P=0.007, respectively). Furthermore, among patients treated with osimertinib, those with high PD-L1 levels exhibited shorter PFS relative to those with low plus negative PD-L1 level (median PFS: 5.0 vs. 17.4 months; P<0.001).

Conclusions

Elevated tumor PD-L1 expression is associated with poor outcomes of osimertinib monotherapy in previously untreated advanced NSCLC patients with EGFR mutation. Further clinical trials are warranted to accumulate evidence demonstrating the effectiveness of combination therapy with osimertinib for EGFR-mutated advanced NSCLC patients with elevated tumor PD-L1 expression.

Trial Registration

UMIN000043942.

Dual PD-L1 and TGF-b blockade in patients with recurrent respiratory papillomatosis

Background

Recurrent respiratory papillomatosis (RRP) is a human papillomavirus (HPV) driven neoplastic disorder of the upper aerodigestive tract that causes significant morbidity and can lead to fatal airway obstruction. Prior clinical study demonstrated clinical benefit with the programmed death-ligand 1 (PD-L1) monoclonal antibody avelumab. Bintrafusp alfa is a bifunctional inhibitor of PD-L1 and transforming growth factor-beta (TGF-b) that has shown clinical activity in several cancer types.

Methods

We conducted a phase II clinical trial evaluating bintrafusp alfa in adults with RRP. Papilloma samples before and after treatment with bintrafusp alfa were assessed for correlates of response with multiplex immunofluorescence as well as immunological and genomic analyses. Post hoc analyses of papilloma samples before and after treatment with avelumab were assessed for comparison.

Results

Dual PD-L1/TGF-b inhibition failed to abrogate papilloma growth in most subjects and increased the frequency of clinically indicated interventions after treatment in four of eight subjects based on each subject’s own historical control. TGF-b neutralization consistently decreased pSMAD3 and p21 and increased Ki67 expression within the basal layers of papillomas, indicating that TGF-b restrained proliferation. These alterations were not observed in papillomas treated with PD-L1 blockade alone. Dual PD-L1/TGF-b inhibition did not enhance anti-HPV immunity within papillomas beyond that observed with PD-L1 blockade. Genomic alterations in TGF-b superfamily genes were infrequent in papillomas and normal mucosa but present in a significant fraction of head and neck carcinomas.

Conclusions

Intact TGF-b signaling restrains proliferation within papillomas, and the use of clinical agents that abrogate this pathway should be avoided in patients with RRP.

Trial registration numbers

NCT03707587 and NCT02859454.

Immune delineation of laryngeal papilloma reveals enhanced neutrophil associated gene profile

Laryngeal papilloma (LP) is a rare benign disease, caused by recurrent multisite papillomas that are referred to as recurrent respiratory papillomatosis (RRP). RRP is caused primarily by two types of human papillomavirus (HPV): HPV6 and HPV11. The immune dysregulation within the microenvironment of the lesions has been shown to likely play a role in the development of RRP. The present study aimed at analyzing the transcriptional profile of immune response genes and cancer-related genes in the LP microenvironment. We used the NanoString^® nCounter^® analysis system to study expression of 730 genes among seven paired samples of LP and healthy laryngeal (HL) tissue. qRT-PCR and flow cytometric analysis was performed to confirm identified transcripts and follow-up scores of infiltrating immune cells, respectively. In total, 113 differentially expressed transcripts were detected of which 37 showed increased expression levels and 76 decreased expression levels in the LP samples compared to the HL samples (fold change ≥ 2). Transcripts with increased expression levels included S100As (A7, A8, and A12), CEACAM1, neutrophil activation associated cytokines (IL8), chemokines (CXCL6), and IL receptors, e.g., IL4R. Transcripts with decreased expression in LP were associated with innate and adaptive immunity. Overall, HPV6 and 11 were present in 67% and 33% of the patients, respectively. There was a significant increase in neutrophils and a significant decrease in CD8⁺ T cells in LP. LP samples display an immune profile characterized by enhanced expression of neutrophilic markers and significantly reduced T cell-associated markers.

The Synthesis of Main Capsid Protein of Anogenital Type HPV6 L1 in Plant Expression System on the Basis of Tomato Fruits

The anogenital type HPV6 L1 major capsid protein was synthesized in a plant expression system on the basis of tomato fruits. The content of HPV6 L1 reached 380 μg per 1 mg of total soluble protein of raw fruit mass, which was represented as a single band with a molecular mass of 56 kDa on the SDS electrophoregram. When orally administrated to mice, the vaccine material from the tomato fruit transgenic for HPV6 L1 induced highly effective antibody immune response with a high titer. The cross-reactivity during the interaction of the antibody to the HPV6 L1 protein from peripheral blood serum of mice vaccinated with HPV6 L1 with the antigenic proteins HPV16 L1, HPV18 L1, HPV31 L1, and HPV45 L1 was found. This is promising for creating a vaccine with a broad reactivity against dangerous anogenital papillomatoses and cervical cancer.

Therapeutic potential of targeting Tfr/Tfh cell balance by low-dose-IL-2 in active SLE: a post hoc analysis from a double-blind RCT study

OBJECTIVE

To investigate the regulation of T follicular regulatory (Tfr) and T follicular (Tfh) cell subtypes by low-dose IL-2 in systemic lupus erythematosus (SLE) in a randomized, double-blind, placebo-controlled clinical trial.

METHODS

A post hoc analysis was performed in a randomized cohort of SLE patients (n=60) receiving low-dose IL-2 therapy (n=30) or placebo (n=30), along with the standard of care treatment. The primary endpoint was the attainment of SLE responder index-4 (SRI-4) at week 12 in the trial. Twenty-three healthy controls were enrolled for T cell subset detection at the same time as the trial. The t-stochastic neighbor embedding (tSNE) analysis of CD4 T subsets based on immune cells flow cytometry markers was performed to distinguish Tfh, Tfh1, Tfh2, Tfh17, and Tfr cell subsets.

RESULTS

Compared with HC, the frequency of Tfr (CXCR5+PD-1low Treg and CXCR5+PD-1high Treg) cells was significantly reduced, while the pro-inflammatory Tfh cells were increased in patients with SLE. The imbalanced Tfh cell was associated with several pathogenic factors (anti-dsDNA antibodies (r=0.309, P=0.027) and serum IL-17 (r=0.328, P=0.021)) and SLE Disease Activity Index (SLEDAI) score (r=0.273, P=0.052). Decreased CXCR5+PD-1low Treg/Tfh and CXCR5+PD-1low Treg/Tfh17 were both associated with increased immunoglobulin M (IgM) (r=-0.448, P=0.002 and r=-0.336, P=0.024, respectively). Efficacy of low-dose IL-2 therapy was associated with a restored Tfr/Tfh cell balance.

CONCLUSION

These data support the hypothesis that promotion of Tfr is associated with decreased disease activities and that low-dose IL-2 therapy can recover Tfr/Tfh immune balance.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registries ( NCT02465580 ).

Biologics for the Treatment of Recurrent Respiratory Papillomatosis

This article aims to educate readers on adjuvant therapies for recurrent respiratory papillomatosis (RRP). Although antivirals are injected locally into papillomas as an adjuvant treatment, new biologics targeting vascular endothelial growth factor or induction of human papillomavirus (HPV)-specific immunity are gaining traction with demonstration of clinical benefit and mechanism of action in retrospective case series and prospective clinical trials. The future of RRP treatment, alone or in combination with surgery, lies in the careful clinical study of vascular and immune targeting agents that balance the risk of adverse events with the chance for elimination of HPV-infected cells.

The Roles of Programmed Cell Death Ligand-1/ Programmed Cell Death-1 (PD-L1/PD-1) in HPV-induced Cervical Cancer and Potential for their Use in Blockade Therapy

BACKGROUND

Cervical cancer induced by infection with human papillomavirus (HPV) remains a leading cause of mortality for women worldwide although preventive vaccines and early diagnosis have reduced morbidity and mortality. Advanced cervical cancer can only be treated with either chemotherapy or radiotherapy but the outcomes are poor. The median survival for advanced cervical cancer patients is only 16.8 months.

METHODS

We undertook a structural search of peer-reviewed published studies based on 1). Characteristics of programmed cell death ligand-1/programmed cell death-1(PD-L1/PD-1) expression in cervical cancer and upstream regulatory signals of PD-L1/PD-1 expression, 2). The role of the PD-L1/PD-1 axis in cervical carcinogenesis induced by HPV infection and 3). Whether the PD-L1/PD-1 axis has emerged as a potential target for cervical cancer therapies.

RESULTS

One hundred and twenty-six published papers were included in the review, demonstrating that expression of PD-L1/PD-1 is associated with HPV-caused cancer, especially with HPV 16 and 18 which account for approximately 70% of cervical cancer cases. HPV E5/E6/E7 oncogenes activate multiple signalling pathways including PI3K/AKT, MAPK, hypoxia-inducible factor 1α, STAT3/NF-kB and microRNA, which regulate PD-L1/PD-1 axis to promote HPV-induced cervical carcinogenesis. The PD-L1/PD-1 axis plays a crucial role in the immune escape of cervical cancer through inhibition of host immune response. Creating an "immune-privileged" site for initial viral infection and subsequent adaptive immune resistance, which provides a rationale for the therapeutic blockade of this axis in HPV-positive cancers. Currently, Phase I/II clinical trials evaluating the effects of PDL1/ PD-1 targeted therapies are in progress for cervical carcinoma, which provide an important opportunity for the application of anti-PD-L1/anti-PD-1 antibodies in cervical cancer treatment.

CONCLUSION

Recent research developments have led to an entirely new class of drugs using antibodies against the PD-L1/PD-1 thus promoting the body's immune system to fight cancer. The expression and roles of the PD-L1/ PD-1 axis in the progression of cervical cancer provide great potential for using PD-L1/PD-1 antibodies as a targeted cancer therapy.

How Enhancing Immunity to Low-Risk HPV Could Cure Recurrent Respiratory Papillomatosis

Recurrent respiratory papillomatosis (RRP) is currently treated with repeat surgical resection of papillomatous disease that does not address the fundamental underlying issue of chronic infection with low-risk human papillomavirus. Here, we review the biology and immunology of low-risk human papillomavirus (HPV) infections. Antiviral or antiangiogenic adjuvant treatments similarly address the papillomatous disease itself but do not activate HPV immunity. It is likely that only through immune-mediated clearance of low-risk HPV infection can patients with RRP be cured. In some patients, this occurs spontaneously. In others with more aggressive disease, adjuvant immunotherapy to activate immunity may be needed. Based on current understanding of antiviral immune responses, the only rational strategy to clear HPV-infected epithelial cells is through activation of the T-lymphocyte arm of the adaptive immune response. Translation of immunotherapies that are Food and Drug Administration-approved or under clinical study for cancer, such as immune checkpoint blockade or engineered therapeutic vaccines, may provide a path toward tolerable and efficacious adjuvant immunotherapy for RRP. LEVEL OF EVIDENCE: NA Laryngoscope, 131:2041-2047, 2021.

Associations of PD-L1, PD-L2, and HLA class I expression with responses to immunotherapy in patients with advanced sarcoma: post hoc analysis of a phase 1/2 trial

BACKGROUND

Although immunotherapy is thought to be a promising cancer treatment, most patients do not respond to immunotherapy. In this post hoc analysis of a phase 1/2 study, associations of programmed death ligand 1 (PD-L1), PD-L2, and HLA class I expressions with responses to dendritic cells (DCs)-based immunotherapy were investigated in patients with advanced sarcoma.

METHODS

This study enrolled 35 patients with metastatic and/or recurrent sarcomas who underwent DC-based immunotherapy. The associations of PD-L1, PD-L2, and HLA class I expressions in tumor specimens, which were resected before immunotherapy, with immune responses (increases of IFN-γ and IL-12) and oncological outcomes were evaluated.

RESULTS

Patients who were PD-L2 (+) showed lower increases of IFN-γ and IL-12 after DC-based immunotherapy than patients who were PD-L2 (-). The disease control (partial response or stable disease) rates of patients who were PD-L1 (+) and PD-L1 (-) were 0% and 22%, respectively. Disease control rates of patients who were PD-L2 (+) and PD-L2 (-) were 13% and 22%, respectively. Patients who were PD-L1 (+) tumors had significantly poorer overall survival compared with patients who were PD-L1 (-). No associations of HLA class I expression with the immune response or oncological outcomes were observed.

CONCLUSIONS

This study suggests that PD-L1 and PD-L2 are promising biomarkers of DC-based immunotherapy, and that addition of immune checkpoint inhibitors to DC-based immunotherapy may improve the outcomes of DC-based immunotherapy.

Immune Escape Is an Early Event in Pre-Invasive Lesions of Lung Squamous Cell Carcinoma

Bronchial dysplasia is the pre-neoplastic lesion recognized for invasive squamous cell carcinoma. The mechanisms leading to invasive squamous cell carcinoma for this lesion are not fully known. Programmed Death-Ligand 1 (PD-L1) expression by the bronchial dysplasia neoplastic epithelium might suggest a response to immunotherapy. The objective of this work is to further characterize PD-L1 and CD8 expression in bronchial dysplasia and bronchial metaplasia compared to normal bronchial epithelium. Immunohistochemical analysis of PD-L1 and CD8 staining were characterized in bronchial dysplasia of 24 patients and correlated with clinical data. We also compared PD-L1 expression in dysplasia samples to 30 normal epithelium and 20 samples with squamous bronchial metaplasia. PD-L1 was never expressed in normal epithelium and in metaplastic epithelium whereas 37.5% of patients with bronchial dysplasia were stained by PD-L1 (p < 0.001). PD-L1 expression was not related to the degree of dysplasia or a medical history of invasive squamous cell carcinoma, while CD8 expression and its localization were related to medical history of squamous cell carcinoma (p = 0.044). Our results show that PD-L1 is expressed in roughly one third of patients with bronchial dysplasia and is not expressed in normal and metaplastic epithelium. This suggests that PD-L1 is expressed in preneoplastic lesions of squamous cell carcinoma.

Altered Monocyte and Langerhans Cell Innate Immunity in Patients With Recurrent Respiratory Papillomatosis (RRP)

The micromilieu within respiratory papillomas supports persistent human papillomavirus (HPV) infection and disease recurrence in patients with recurrent respiratory papillomatosis (RRP). These patients show polarized (T_H2-/Treg) adaptive immunity in papillomas and blood, enriched immature Langerhans cell (iLC) numbers, and overexpression of cyclooxygenase-2/prostaglandin E₂ (PGE₂) in the upper airway. Blood monocyte-derived, and tissue-derived iLCs from RRP patients and controls were now studied to more fully understand innate immune dysregulation in RRP. Patients' monocytes generated fewer iLCs than controls, due to a reduced fraction of classical monocytes that generated most but not all the iLCs. Prostaglandin E₂, which was elevated in RRP plasma, reduced monocyte-iLC differentiation from controls to the levels of RRP patients, but had no effect on subsequent iLC maturation. Cytokine/chemokine responses by iLCs from papillomas, foreskin, and abdominal skin differed significantly. Freshly derived tissue iLCs expressed low CCL-1 and high CCL-20 mRNAs and were unresponsive to IL-36γ stimulation. Papilloma iLCs uniquely expressed IL-36γ at baseline and expressed CCL1 when cultured overnight outside their immunosuppressive microenvironment without additional stimulation. We conclude that monocyte/iLC innate immunity is impaired in RRP, in part due to increased PGE₂ exposure in vivo. The immunosuppressive papilloma microenvironment likely alters iLC responses, and vice versa, supporting T_H2-like/Treg HPV-specific adaptive immunity in RRP.

Laryngeal Tumor Microenvironment

Tumor microenvironment has been extensively studied in various forms of cancer, like head and neck squamous cell carcinoma. Progress in the field revealed the prognostic significance of the various components of the tumor's ecosystem and led to changes in treatment strategies, like including immunotherapy as an important tool. In this chapter, the microenvironment of tumors with a special interest in laryngeal cancer will be described. The issues assessed include innate immune response factors, like neutrophils, neutrophil extracellular traps (NET), platelets, macrophages M1 or M2, dendritic cells, natural killer cells, as well as adaptive immunity aspects, like cytotoxic, exhausted and regulatory T cells, and immune checkpoints (PD-1/PD-L1, CTLA4). Also, stroma-associated factors, like fibroblasts, fibrosis, extracellular matrix, vessels and perineural invasion, hypoxia and cancer metabolism aspects, as well as the pre-metastatic niche, exosomes and cGAS-STING, are reviewed.

Immunological tolerance of low-risk HPV in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is characterized by benign exophytic lesions of the respiratory tract caused by the human papillomavirus (HPV), in particular low-risk HPV6 and HPV11. Aggressiveness varies greatly among patients. Surgical excision is the current standard of care for RRP, with adjuvant therapy used when surgery cannot control disease recurrence. Numerous adjuvant therapies have been used to control RRP with some success, but none are curative. Current literature supports a polarization of the adaptive immune response to a T helper type 2 (Th2)-like or T regulatory phenotype, driven by a complex interplay between innate immunity, adaptive immunity and HPV6/11 proteins. Additionally, certain immunogenetic polymorphisms can predispose individuals to an HPV6/11-tolerant microenvironment. As a result, immunomodulatory efforts are being made to restore the host immune system to a more balanced T cell phenotype and clear viral infection. Literature has shown exciting evidence for the role of HPV vaccination with Gardasil or Gardasil-9 as both primary prevention, by decreasing incidence through childhood vaccinations, and secondary prevention, by treating active RRP disease. Multi-institution randomized clinical trials are needed to better assess their efficacy as treatment for active disease. Interestingly, a DNA vaccine has recently shown in-vitro success in generating a more robust CD8⁺ T cell response. Furthermore, clinical trials for programmed death 1 (PD-1) inhibitors are under investigation for RRP management. Molecular insights into RRP, in particular the interplay between RRP and the immune system, are needed to advance our understanding of this disease and may lead to the identification of immunomodulatory agents to better manage RRP.

The expression of C-MYC in gastric adenocarcinoma is associated with PD-L1 and FOXP3 expression: C-MYC overexpression is a good prognostic factor

BACKGROUND

C-MYC appears to initiate and maintain tumorigenesis through modulation of immune regulatory molecules such as PD-L1. The aim of our research was to evaluate the clinical implication of C-MYC expression in gastric adenocarcinoma in relation to the expression of the immune regulatory molecules PD-L1 and FOXP3.

METHODS

Tissue samples were acquired from 182 cases of gastric adenocarcinoma that were surgically resected at Kyung Hee University Hospital at Gangdong from 2006 to 2012. Immunohistochemical staining for C-MYC, PD-L1, CD8 and FOXP3 was done.

RESULTS

C-MYC overexpression showed a significant correlation with smaller tumor size, lower T category, lower N category, lower recurrence rate, and less lymphatic invasion. And C-MYC overexpression was negatively correlated with PD-L1 expression. The tumoral FOXP3 was positively correlated with C-MYC overexpression and Tregs count. PD-L1 expression was positively correlated with Tregs, CD8 + T cells, and tumor infiltrating lymphocytes (TIL). Tregs count was positively correlated with CD8 + T cells and TIL. CD8 + T cells was positively correlated with TIL.

CONCLUSION

We discovered that the immune regulatory effect of C-MYC and PD-L1, and the tumor suppressor function of tumoral FOXP3 had a significant influence on the tumor microenvironment (Tregs, CD8 + T cells, and tumor infiltrating lymphocytes) in a complex manner. The C-MYC overexpression is a good prognostic factor in gastric adenocarcinoma.

Retrospective analysis of docetaxel in combination with ramucirumab for previously treated non-small cell lung cancer patients

Background

Current clinical trials demonstrated that combination regimens comprising chemotherapy and immunotherapy lead to better patient outcomes compared to chemotherapy alone as the first line of treatment for non-small cell lung cancer (NSCLC). In addition, the combination therapy of docetaxel (Doc) and ramucirumab (Ram) was considered one of the standard treatments for advanced or relapsed NSCLC patients. However, little is known about the therapeutic responders of this combination therapy among previously treated NSCLC patients. In the present study, we aimed to identify predictive factors for therapeutic response, including programmed death-ligand 1 (PD-L1) expression in tumors, for Doc treatment in combination with Ram.

Methods

We retrospectively analyzed a total of 135 advanced or relapsed NSCLC patients who were refractory to platinum-based chemotherapy at eleven institutions in Japan between July 2016 and November 2018.

Results

Our observations showed that PD-L1 expression in tumors is not associated with the efficacy of combined therapy of Doc and Ram in previously treated NSCLC patients. Analysis of the patient clinical profiles indicated that prior treatment with immune checkpoint inhibitors (ICIs) is a reliable predictor for the good progression-free survival (PFS) to this combination therapy (P=0.041).

Conclusions

Our retrospective study indicated that combination regimens comprising chemotherapy and ICIs followed by Doc and Ram could be an optimal therapeutic option for NSCLC patients regardless of the PD-L1 status of tumors. Further investigations are required to strengthen clinical evidence demonstrating the effectiveness of the combination therapy of Doc plus Ram in previously treated NSCLC patients.

Safety and clinical activity of PD-L1 blockade in patients with aggressive recurrent respiratory papillomatosis

Background

Recurrent respiratory papillomatosis (RRP) is a human papillomavirus (HPV)-driven disorder that causes substantial morbidity and can lead to fatal distal airway obstruction and post-obstructive pneumonias. Patients require frequent surgical debridement of disease, and no approved systemic adjuvant therapies exist.

Methods

A phase II study was conducted to investigate the clinical activity and safety of programmed death-ligand 1 (PD-L1) blockade with avelumab in patients with RRP.

Results

Twelve patients were treated. All patients with laryngeal RRP displayed improvement in disease burden, and 5 of 9 (56%) displayed partial responses. None of 4 patients with pulmonary RRP displayed a response. Using each patient’s surgical history as their own control, patients required fewer surgical interventions after avelumab treatment (p = 0.008). A subset of partial responders developed HPV-specific reactivity in papilloma-infiltrating T-cells that correlated with reduced HPV viral load and an increased Tissue Inflammation Signature.

Conclusions

Avelumab demonstrated safety and clinical activity in patients with laryngeal RRP. Further study of immune checkpoint blockade for RRP, possibly with longer treatment duration or in combination with other immunotherapies aimed at activating antiviral immunity, is warranted.

Trial registration

NCT, number NCT02859454, registered August 9, 2016.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0603-3) contains supplementary material, which is available to authorized users.

Expression of programmed cell death-ligand 1 in oral squamous cell carcinoma and oral leukoplakia is associated with disease progress and CD8+ tumor-infiltrating lymphocytes

OBJECTIVE

In recent years, monoclonal antibodies targeting programmed cell death-ligand 1 (PD-L1) have become a promising cancer immunotherapy. However, the role of PD-L1 in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs), including oral leukoplakia (OLK), remains controversial. The aim of the present study was to investigate the expression level of PD-L1 in OSCC and OPMDs, and examine its relationship with CD8 expression and different clinicopathological features.

METHOD

Expression of PD-L1 and CD8 were conducted in 41 OSCC, 21 OLK, and 25 normal mucosa samples by immunohistochemistry. Then, the density of PD-L1 expression was measured, and its correlation with CD8 expression and different clinicopathological features was analyzed.

RESULTS

PD-L1 protein was detected in 97.6% of OSCC, 61.9% of OLK, and 0% of normal tissues. PD-L1 was highly expressed in human OSCC tissue (P < 0.0001), when compared to both OLK and control tissues. PD-L1 positivity was significantly associated with CD8 density (P < 0.0001, r = 0.8491). The PD-L1 high expression OSCC group displayed a trend for improved overall survival (OS) and disease-free survival (DFS) compared to the low expression group, although the differences were not significant. Moreover, the expression level of PD-L1 in OSCC was positively correlated with the pathological grade (P < 0.0001), but it was independent of age, gender, smoking, drinking, tumor size, lymph node status, or recurrence (P > 0.05). Also, there was a significant upregulation of PD-L1 expression observed in the OLK group compared to the control group (P < 0.0001). PD-L1 positivity in OLK patients was associated with gender and smoking habits (P < 0.05), but it did not correlate with age, drinking, or dysplasia (P > 0.05).

CONCLUSION

The upregulation of PD-L1 may be associated with disease progress and CD8+ tumor-infiltrating lymphocytes in oral premalignant and malignant lesions.

Clinical Activity of Nivolumab for Human Papilloma Virus-Related Juvenile-Onset Recurrent Respiratory Papillomatosis

BACKGROUND

Juvenile-onset recurrent respiratory papillomatosis (JO-RRP) is a human papilloma virus-mediated progressive benign neoplasm that affects children and young adults. Primary management consists of regular surgical debulking to maintain airway patency and vocal function. Like condyloma acuminata, JO-RRP is associated with immune dysregulation, and T cells isolated from papillomas express an anergic phenotype. Therefore, we hypothesized that programmed death protein 1 axis inhibition could stabilize tumor growth.

MATERIALS AND METHODS

We treated two patients with refractory JO-RRP using nivolumab, with the primary objective of assessing clinical activity. We explored baseline papilloma features using immunohistochemistry and comprehensive genomic profiling.

RESULTS

Both patients experienced symptomatic improvement, and interval laryngoscopies revealed a reduction in papillomatosis burden. One patient has not required subsequent surgical debridement for almost 2 years. On pathologic examination of pretreatment papillomas from both cases, infiltrating T cells were evident in the papilloma stroma, and papilloma programmed death ligand 1 expression was absent. Papilloma mutational load ranged between three and six mutations per megabase for each case. From on-treatment biopsy tissue, a higher amount of intraepithelial T cells and programmed death ligand 1 expression were detected in the papilloma.

CONCLUSION

Nivolumab appears to have promising activity in JO-RRP, and further clinical investigation with more patients in clinical trials is warranted.

IMPLICATIONS FOR PRACTICE

To the authors' knowledge, this article is the first report describing clinical activity with a programed cell death-1 (PD-1) inhibitor to treat a rare but detrimental type of respiratory tract epithelial neoplasm that afflicts young adults. Two patients were treated, and tumor features, such as mutational load, were examined with the intent to stimulate future hypotheses for translational research. The safety and activity of PD-1 inhibitors in this population still need to be corroborated in clinical trials and should not yet be adopted into clinical practice.

Expression of programmed death ligand-1 and programmed death-1 in samples of invasive ductal carcinoma of the breast and its correlation with prognosis

The aim of the current study is to investigate programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) expressions and to analyze the relationship between the expression of PD-L1 and PD-1 proteins and the molecular type, clinicopathological factors, and prognosis of invasive ductal carcinoma. We enrolled 136 patients with invasive ductal carcinoma of the breast. The expression of PD-L1 in tumor cells and that of PD-1 on paratumor-infiltrating immune cells was detected by immunohistochemistry, and the data were analyzed using SPSS software. The positive expression rates of PD-L1 and PD-1 in triple-negative breast cancer (TNBC) were 47.8 and 43.5%, which were higher than those of other subtypes (P<0.05). The expression of PD-L1 in tumor cells was correlated with the expression of estrogen receptor, progesterone receptor, and Ki-67 (P<0.05). The expression of PD-1 in the tumor-infiltrating immune cells was correlated with the expression of estrogen receptor, progesterone receptor, and Ki-67 and the histological grade (P<0.05). The expression of PD-L1 in tumor cells was correlated with the expression of PD-1 in paratumor-infiltrating immune cells (P<0.001). The expression of PD-L1 in tumor cells was found to be an independent prognostic risk factor with the progression-free survival rate for breast invasive ductal carcinoma (P=0.003). These results indicate that PD-L1 and PD-1 were highly expressed in TNBC which suggests that patients with TNBC may benefit from targeted immune therapies to a greater degree than patients with other subtypes. PD-L1 expression is an independent risk factor for breast invasive ductal carcinoma and expression of PD-L1 is expected to be a prognostic factor for breast cancer.

Expression of PD-L1 and SOX2 during rectal tumourigenesis: Potential mechanisms for immune escape and tumour cell invasion

Immunoediting is defined as a process whereby tumour cells develop the capacity to escape immune cell recognition. Accumulating evidence suggests that cancer stem-like cells (CSCs) have an enhanced capacity to interact with the immune system. The expression of CSCs and immune cell-associated markers has been demonstrated to change with disease progression from premalignant lesions to invasive cancer. The present study investigated the expression of putative CSC and immune cell-associated markers in different stages of progression from dysplasia to invasive malignancy in rectal lesions. Immunohistochemistry was performed for the CSC markers Lgr5 and SOX2 and the immune-associated markers CD8, Foxp3 and PD-L1 in 79 cases of endoscopically-excised rectal lesions, ranging from low grade adenoma (LG) to invasive adenocarcinoma (AdCa). CD8 and Foxp3 expression significantly increased with advances in disease progression [AdCa vs. LG: Odds ratio (OR) 4.33; 95% confidence interval (CI), 1.16–16.3; P=0.03 and OR, 40.5; 95% CI, 6.57–249.6; P<0.0001, respectively]. An increase in programmed death-ligand 1 (PD-L1) expression was also observed with disease progression (OR, 24.0; 95% CI, 4.23–136.2; P=0.0003). The expression of sex determining region Y-box 2 (SOX2) did not correlate with disease progression, although an elevated expression was observed in areas with high grade dysplasia. Increased PD-L1 expression may be a mechanism by which tumour cells evade immune recognition, facilitating tumour cell invasion in rectal cancer. The expression of SOX2 in areas with high grade dysplasia may indicate the de-differentiation of tumour cells, or the activation of migration pathways for invasion.

Prognostic value of PD-1 and PD-L1 expression in patients with metastatic clear cell renal cell carcinoma

OBJECTIVE

In renal cell carcinoma (RCC), several prognostic biomarkers have been identified and are under investigation. Several reports have shown that the expression of programmed death 1 (PD-1) and its ligand PD-L1 is associated with poor outcome for patients with RCC. The present study is aimed at evaluating the expression of PD-1 and PD-L1 and to investigate their clinical and prognostic significance in patients with clear cell RCC (CCRCC) having received molecular targeted therapies. In addition, we also evaluated the relationship between the expression of PD-1 and PD-L1 and intratumoral tumor infiltrating lymphocytes (TILs).

METHODS

A total of 33 patients with metastatic CCRCC who underwent surgery and received molecular targeted therapies from March 2008 to April 2016 were retrospectively reviewed and analyzed. Tissue specimens from the patients were analyzed for PD-1 and PD-L1 expression by immunohistochemistry.

RESULTS

The median patient age was 64 years old (range=53-78). The majority of patients were male (81.8%). All Memorial Sloan Kettering Cancer Center risk groups were represented among the patients with 39.4% with favorable-, 51.5% with intermediate- and 9.1% with poor-risk. The expression of PD-1 and PD-L1 was observed in 16 (48.5%) and 9 (27.3%) patients, respectively. The expression of PD-1 and PD-L1 was associated with a larger primary renal tumor size, higher nuclear grade and sarcomatoid feature. Kaplan-Meier analysis revealed that no significant difference in progression free survival of first line molecular targeted therapy was found for PD-1 (P=0.2396) and PD-L1 (P=0.5919) expression. However, PD-1 expression has a significant worse impact on overall survival (OS) (P=0.0385), while for PD-L1 expression only a trend is seen for OS (P=0.1542). The patients with PD-1 and PD-L1 expression showed higher infiltration of CD4 (P<0.0001 and P<0.0001, respectively), CD8 (P=0.0328 and P=0.0044, respectively) and FOXP3 (P<0.0001 and P=0.0033, respectively) positive TILs.

CONCLUSION

PD-1 and PD-L1 expression is significantly associated with adverse clinicopathological features in CCRCC. Furthermore, PD-1 expression could be one of the biomarkers suggesting poor outcome in patients with metastatic CCRCC receiving molecular targeted therapies.

The prognostic significance of pdl1 and foxp3 expressions in tumor cells and the tumor microenvironment of ovarian epithelial tumors

BACKGROUND

The aim of this study is to determine the prognostic values of PDL1 expression in ovarian epithelial tumors and to detect the presence of FOXP3-positive T reg cells in the tumor microenvironment.

METHODS

This study included patients with benign, borderline or malignant ovarian serous tumors (n=82), mucinous cancer (n=17) and endometrioid cancer (n=36). FOXP3 and PDL1 were immunohistochemically evaluated and compared with histopathological and clinical prognostic parameters.

RESULTS

There was no expression of PDL1 in any tumor cell. However, PDL1-positive inflammatory cells were seen in 10 cases (7.3%) with mucinous carcinoma (n=6), endometrioid carcinoma (n=2), borderline (n=1), and benign (n=1) serous tumors. It was also determined that there was a significant positive correlation between PD-L1 expression in tumor infiltrating cells and survival (P<0.01). In 47 (34.3%) cases, there were FOXP3-positive cells. The number of FOXP3-positive cells was significantly higher in ovarian cancer, especially in serous and endometrioid carcinomas, rather than benign and borderline tumors (P=0.007). But there was no statistically significant association between the survival times and the presence of T regs (P=0.241).

CONCLUSIONS

This study demonstrated that the presence of FOXP3 and PDL1-positive regulatory T cells in TILs was associated with mainly malignant tumors. We also found that the presence of PD-L1-positive inflammatory cells has a positive effect on survival.

Tristetraprolin Overexpression in Gastric Cancer Cells Suppresses PD-L1 Expression and Inhibits Tumor Progression by Enhancing Antitumor Immunity

The RNA-binding protein tristetraprolin (TTP) binds to adenosine-uridine AU-rich elements in the 3'-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their microenvironment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PD-L1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

Clinicopathological and prognostic significance of PD-L1 expression in sarcoma: A systematic review and meta-analysis

Programmed cell death-ligands 1 (PD-L1) is a key immune checkpoint protein and a promising therapeutic target for malignancy tumor immunotherapy. The prognostic value of PD-L1 in patients with bone and soft tissue sarcoma remains controversial. Therefore, this meta-analysis is conducted to evaluate the associations of PD-L1 expression with overall survival (OS), progression-free survival (PFS), and clinicopathological characteristics of sarcomaA comprehensive literature search of PubMed, Web of Science, Embase, and Cochrane Library was conducted for relevant studies. A total of 14 studies published from 2013 to 2017 were included. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted from included studies to assess the association between PD-L1 expression and OS, PFS of patients with sarcoma. Other relevant data were extracted to evaluate the correlations of PD-L1 expression with risk and clinicopathological characteristics of sarcoma. Stata 12.0 software was applied to calculate the strength of association between PD-L1 expression and sarcoma.In total, 14 articles containing 15 independent studies and 1,451 patients were included in this meta-analysis. We found that the high PD-L1 expression was associated with poorer overall survival (HR 1.27, 95% CI: 0.70-1.84 P = .000) and poorer events-free survival (HR 2.05, 95% CI: 1.55-2.70, P = .000) in bone and soft-tissue sarcoma patients. Additionally, we conducted subgroup analysis according to histology type, ethnicity, target of PD-L1 assessment, cutoff, the significant correlations with poor overall survival and events-free survival were also observed. In contrast none of the clinicopathological characteristics (gender, age, tumor site, tumor grade, tumor depth, tumor necrosis rate, metastasis, recurrence, chemotherapy, radiotherapy) was found to be associated with PD-L1 expression in our analysis.The findings from this meta-analysis indicate that PD-L1 expression might be a useful predicative factor of poor prognosis for patients with bone and soft tissue sarcoma.

The PD-1 and PD-L1 pathway in recurrent respiratory papillomatosis

OBJECTIVES/HYPOTHESIS

Generation of an immunosuppressive microenvironment may enable a persistent human papillomavirus infection in the setting of an otherwise normal immune system. We hypothesized that expression of the T-lymphocyte co-inhibitory receptor programmed death 1 (PD-1) and its ligand PD-L1 would be increased in the recurrent respiratory papillomatosis (RRP) microenvironment compared to normal controls.

STUDY DESIGN

Case-control study.

METHODS

Formalin-fixed paraffin-embedded respiratory papilloma and normal controls were obtained under institutional review board approval, stained for CD4, CD8, FoxP3, and PD-1, and scored by automated cell count. PD-L1 staining was scored by a blinded pathologist using an adjusted inflammation score that accounted for epithelial and immune infiltrate.

RESULTS

Thirty-nine RRP cases and seven controls were studied. All immunologic markers demonstrated significantly increased staining in RRP specimens compared to normal controls (all P < .01). PD-1 correlated with both CD4 (P < .0001) and CD8 (P < .001) cell counts. Epithelial staining for PD-L1 (68%) and PD-L1+ infiltrating immune cells (76%) were observed in the majority of papilloma samples. The strongest staining for PD-L1 was usually observed in the basal papilloma layer adjacent to the immunologic infiltrate in the vascular core. Disease severity inversely correlated with CD8 cell counts (P = .01). A correlation between disease severity and other immunologic markers was not observed.

CONCLUSIONS

Most RRP specimens demonstrate PD-1 T-lymphocyte infiltration and PD-L1 expression on both papilloma and infiltrating immune cells. This study suggests that this checkpoint pathway may be contributing to local immunosuppression in RRP, and opens the door for clinical trials utilizing PD-blocking monoclonal antibodies.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:E27-E32, 2018.