Loss of CD28 within CD4+ T cell subsets from cervical cancer patients is accompanied by the acquisition of intracellular perforin, and is further enhanced by NKG2D expression

Interaction of microbiota, mucosal malignancies, and immunotherapy-Mechanistic insights

The microbiome has emerged as a crucial modulator of host-immune interactions and clearly impacts tumor development and therapy efficacy. The microbiome is a double-edged sword in cancer development and therapy as both pro-tumorigenic and anti-tumorigenic bacterial taxa have been identified. The staggering number of association-based studies in various tumor types has led to an enormous amount of data that makes it difficult to identify bacteria that promote tumor development or modulate therapy efficacy from bystander bacteria. Here we aim to comprehensively summarize the current knowledge of microbiome-host immunity interactions and cancer therapy in various mucosal tissues to find commonalities and thus identify potential functionally relevant bacterial taxa. Moreover, we also review recent studies identifying specific bacteria and mechanisms through which the microbiome modulates cancer development and therapy efficacy.

CD200+ cytotoxic T lymphocytes in the tumor microenvironment are crucial for efficacious anti-PD-1/PD-L1 therapy

Anti-PD-1/PD-L1 therapy, either by anti-PD-1 antibody or anti-PD-L1 antibody, has efficacy by reinvigorating tumor-infiltrating CD8⁺ T cells in a subset of patients with cancer, but it has unequal effects on heterogeneous CD8⁺ T cell populations. Hence, the subset crucial to efficacious PD-1 blockade therapy remains elusive. Here, we found an increase in tumor-infiltrating CD200⁺ cytotoxic T lymphocytes (CTLs) upon PD-1/PD-L1 blockade, with higher proportions of CD200⁺ T cells positively related to a favorable clinical outcome to anti-PD-1/PD-L1 therapy in three independent cohorts of patients with cancer. Using multiple mouse tumor models, we demonstrated that CD200⁺ CTLs are essential for efficacious anti-PD-L1 therapy. Mechanistically, we observed a unique chromatin landscape in CD200⁺ CTLs and found that these cells are enriched for tumor antigen-specific CTLs and have antitumor effector functions. Coinoculation of CD200⁺ CTLs with tumor cells led to robust tumor regression in two transplanted mouse models. Clinically, we found that infiltration of CD200⁺ CTLs into tumors could predict immunotherapy efficacy in six patient cohorts. Together, our findings reveal that CD200⁺ CTLs in the tumor microenvironment are crucial for efficacious anti-PD-1/PD-L1 therapy and could serve as a predictor of successful immunotherapy in the clinic.

A novel ten-gene prognostic signature for cervical cancer based on CD79B-related immunomodulators

The identification of immune-related prognostic biomarkers opens up the possibility of developing new immunotherapy strategies against tumors. In this study, we investigated immune-related biomarkers in the tumor microenvironment to predict the prognosis of cervical cancer (CC) patients. ESTIMATE and CIBERSORT algorithms were used to calculate the abundance of tumor-infiltrating immune cells (TICs) and the amount of immune and stromal components in cervical samples (n = 309) from The Cancer Genome Atlas. Ten immune-related differentially expressed genes associated with CC survival were identified via intersection analyses of multivariate Cox regression and protein-protein interactions. CD79B was chosen for further study, and its prognostic value and role in anti-CC immune functions were analyzed. Differential expression analysis and qRT-PCR validation both revealed that CD79B expression was down-regulated in CC tissues. Survival analysis suggested that a high level of CD79B expression was associated with good prognosis. In the clinical correlation analysis, CD79B expression was found to be related to primary therapy outcome, race, histological type, degree of cell differentiation, disease-specific survival, and progression-free interval. GSEA showed that the function and pathway of CD79B were mainly related to immune activities. Meanwhile, CD79B expression was correlated with 10 types of TICs. Based on CD79B-associated immunomodulators, a novel immune prognostic signature consisting of 10 genes (CD96, LAG3, PDCD1, TIGIT, CD27, KLRK1, LTA, PVR, TNFRSF13C, and TNFRSF17) was established and validated as possessing good independent prognostic value for CC patients. Finally, a nomogram to predict personalized 3- and 5-year overall survival probabilities in CC patients was built and validated. In summary, our findings demonstrated that CD79B might be a potential prognostic biomarker for CC. The 10-gene prognostic signature independently predicted the overall survival of patients with CC, which could improve individualized treatment and aid clinical decision-making.

Expression of CD28 in Hepatocellular Carcinoma and Its Prognostic Value

Background: CD28 expression is correlated with malignancy development in long-term survivors after liver transplantation. Immune cell activation is mediated by the interaction of CD28 with CD4 and CD8. Objectives: In this study, we attempted to investigate the expression level and prognostic value of CD28 in hepatocellular carcinoma (HCC). Methods: A total of 54 HCC patients with complete clinical information were examined. The expression level of CD28 in HCC tissues was detected by immunohistochemistry. The correlations of CD28 expression with clinical characteristics, CD4+/CD8+ T-cells, and prognosis in HCC were analyzed. The expression profile of CD28 and survival time of HCC patients were retrieved from the TCGA database, followed by survival analysis. Results: The positive expression rate of CD28 in HCC tissues was 70.73%. The CD28 expression was significantly higher in the positive expression group (area: 659174.9 ± 670060, IOD: 123348.3 ± 106348.6) than in the negative expression group (area: 8405.7 ± 9983.3, IOD: 1959.6 ± 2117.7) (P < 0.01). The CD4+ and CD8+ cell counts were 526.13 ± 258.17 cells/µL and 383.93 ± 223.39 cells/µL, respectively. The expression level of CD28 was significantly related to the degree of differentiation and the number of CD4+ and CD8+ T-cells (P < 0.05). The survival time of patients was longer in the positive CD28 expression group than in the negative expression group. Based on the CD28 expression profiles of 406 HCC patients retrieved from the TCGA database, patients with high CD28 expression showed a better prognosis than those with low expression (P < 0.05). Conclusions: CD28 may play a vital role in the occurrence, development, and prognosis of HCC by interacting with CD4+ and CD8+ T-cells. Thus, CD28 could be suggested as the immune checkpoint target for HCC treatment.

Accumulation of CD28null Senescent T-Cells Is Associated with Poorer Outcomes in COVID19 Patients

Coronavirus disease 2019 (COVID-19), a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes infectious disease, and manifests in a wide range of symptoms from asymptomatic to severe illness and even death. Severity of infection is related to many risk factors, including aging and an array of underlying conditions, such as diabetes, hypertension, chronic obstructive pulmonary disease (COPD), and cancer. It remains poorly understood how these conditions influence the severity of COVID-19. Expansion of the CD28null senescent T-cell populations, a common phenomenon in aging and several chronic inflammatory conditions, is associated with higher morbidity and mortality rates in COVID-19. Here, we summarize the potential mechanisms whereby CD28null cells drive adverse outcomes in disease and predispose patients to devastating COVID-19, and discuss possible treatments for individuals with high counts of CD28null senescent T-cells.

Envisioning the immune system to determine its role in pancreatic ductal adenocarcinoma: Culprit or victim?

Pancreatic ductal adenocarcinoma has a poor 5-year survival rate that makes it one of the most fatal human malignancies. Unfortunately, despite the serious improvement in the survival of most cancers, there has been a minor advance in pancreatic cancer (PC). Major advances in PC treatment have been assessed over the bygone twenty-year time span, yet some complications make the survival of the patients shorter. Getting to know the PC tumor microenvironment (TME) and the immunosuppression that happens during the pathogenesis of this malignancy could be a great help to understand the nature of the immune system and find better treatment modalities based on it. Although many immune cells are present in PC, immunosuppression of the TME leads to severe immune dysfunction in the patients, therefore immune effectors fail to do their functions. Lately, immunotherapy has been presented as one of the promising treatment strategies for different malignancies including hepatocellular carcinoma, melanoma, non-small cell lung cancer, and kidney cancer. In PC, there has been shown promising results centered around the TME, immune checkpoint inhibitors, cancer vaccines, and other approaches especially when used as combinational therapy. Here we dig a little deeper into the role of the immune system and possible therapeutic options in the treatment of PC.

The combined action of monocytic myeloid-derived suppressor cells and mucosal-associated invariant T cells promotes the progression of cervical cancer

One of the most common promoters of the initiation and growth of the tumor is an immune disturbance. Numerous immune cells and inflammatory factors play a role in the tumor-immune microenvironment. However, few studies have investigated the correlation between these immunological events and clinical consequences in cervical cancer. We measured the levels of numerous inflammatory mediators and frequencies of regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs) and mucosal-associated invariant T (MAIT) cells in peripheral blood (PB) of cervical cancer patients. Cervical cancer patients showed elevated production of interleukin (IL)-18 and plasma C-C chemokine ligand (CCL) 3/5. Meanwhile, an accumulation of C-C chemokine receptor 5 (CCR5) monocytic (Mo)-MDSCs and Tregs was observed. The cervical cancer group displayed increased frequencies of CD8⁺ , CD4⁺ and highly activated CD38⁺ CD8⁺ MAIT cells, and reduction of double-negative (DN) and PD1(CD279⁺ ) DN MAIT cells. Importantly, it was demonstrated that MAIT cells were positively related to Mo-MDSCs. Furthermore, an elevated concentration of PD1(CD279⁺ ) DN MAIT cells was significantly related to increased progression-free survival of patients with cervical cancer. In conclusion, our study suggests that the combined action of Mo-MDSCs and MAIT cells might be associated with the progression of cervical cancer, and the frequency of DN MAIT cells in the peripheral blood mononuclear cells was associated with the survival benefit of patients.

Cervical Cancer: Emerging Immune Landscape and Treatment

Immune cells are essential for defending the body’s balance and have increasingly been implicated in controlling tumor growth. In cervical cancer (CC), the immune landscape is extensively connected with human papillomavirus (HPV) status. Recent insights from studies have revealed that as a result of infection with HPV, immune cell populations such as lymphocytes or monocytes change during carcinogenesis. Immune therapy, in particular checkpoint inhibitors, those targeting PD-1 or PD-L1, has shown promising efficacy. This article reviews the immune landscape and immunotherapy of CC.

First report of expansion of CD4+/CD28 null T-helper lymphocytes in adult patients with idiopathic autoimmune hemolytic anemia

CD28 null T helper (T_h) cells are rare in healthy individuals, but they are increased in various inflammatory and immune-mediated diseases. In this study, we determined the size of the CD4⁺/CD28 null T lymphocyte compartment in the peripheral blood of 40 autoimmune hemolytic anemia (AIHA) patients (idiopathic and secondary) and 20 healthy control subjects, using tri-color flow cytometry. The frequency and absolute count of CD4⁺/CD28 null T helper (T_h) cells was significantly higher in idiopathic AIHA patients, compared to healthy controls (p = 0.001 and 0.001, respectively) and to patients with secondary AIHA (p = 0.04 and 0.01, respectively). The percentage of CD4⁺/CD28 null T_h cells was also negatively correlated to the hemoglobin (Hb) level (p = 0.03). These findings demonstrate, for the first time, the expansion of this phenotypically-defined population of T lymphocytes in patients with idiopathic AIHA and indicate that it likely plays an etiological role in the development of this disease. However, establishing the use of this marker for diagnosis or monitoring treatment of such patients needs further studies.

Astilbin promotes the induction of regulatory NK1.1- CD4+ NKG2D+ T cells through the PI3K, STAT3, and MAPK signaling pathways

Astilbin is a potential agent for autoimmune and inflammatory diseases and has a protective effect in mice with DSS-induced colitis. NK1.1^- CD4⁺ NKG2D⁺ T cells are a subpopulation of regulatory T cells that produce TGF-β1 and IL-10. Whether astilbin directly promotes the induction of NK1.1^- CD4⁺ NKG2D⁺ T cells and whether these astilbin-stimulated T cells exert an immune-regulatory role remain unclear. Here, we show that astilbin efficiently induces the production of NK1.1^- CD4⁺ NKG2D⁺ T cells with high expressions of TGF-β1, IL-10, CCR6, and CCR9 in a dose-dependent manner ex vivo. These regulatory T cells also substantially inhibit the activities of CD8⁺ T cells and macrophages. Intraperitoneal injection of astilbin ameliorates the severity of colitis with an increase in the frequency of NK1.1^- CD4⁺ NKG2D⁺ T cells in the colon tissue of DSS-treated mice. Moreover, adoptive transfer of NK1.1^- CD4⁺ NKG2D⁺ T cells induced by astilbin remarkably protects against the onset of DSS-induced colitis. Finally, the PI3K, STAT3, and MAPK signaling pathways are involved in the induction of NK1.1^- CD4⁺ NKG2D⁺ T cells by astilbin. Taken together, our study elucidates a new immune-regulatory mechanism of astilbin by inducing the regulatory NK1.1^- CD4⁺ NKG2D⁺ T cells and indicates a potential clinical use of astilbin for patients with inflammatory bowel diseases.

Antitumor Response and Immunomodulatory Effects of Sub-Microsecond Irreversible Electroporation and Its Combination with Calcium Electroporation

In this work, we have investigated the feasibility of sub-microsecond range irreversible electroporation (IRE) with and without calcium electroporation in vivo. As a model, BALB/C mice were used and bioluminescent SP2/0 myeloma tumor models were developed. Tumors were treated with two separate pulsed electric field (PEF) pulsing protocols PEF1: 12 kV/cm × 200 ns × 500 (0.006 J/pulse) and PEF2: 12 kV/cm × 500 ns × 500 (0.015 J/pulse), which were delivered with and without Ca²⁺ (168 mM) using parallel plate electrodes at a repetition frequency of 100 Hz. Both PEF1 and PEF2 treatments reduced tumor growth and prolonged the life span of the mice, however, the PEF2 protocol was more efficient. The delay in tumor renewal was the biggest when a combination of IRE with calcium electroporation was used, however, we did not obtain significant differences in the final mouse survival compared to PEF2 alone. Anti-tumor immune responses were also investigated after treatment with PEF2 and PEF2+Ca. In both cases the treated mice had enlarged spleens and increased spleen T cell numbers, lower percentages of suppressor cell subsets (conventional CD4⁺CD25⁺ Treg, CD4⁺CD25⁻DX5⁺ Tr1, CD8⁺DX5⁺, CD4⁺CD28⁻, CD8⁺CD28⁻), changed proportions of Tcm and Tef/Tem T cells in the spleen and increased amount of tumor cell specific antibodies in the sera. The treatment based on IRE was effective against primary tumors, destroyed the tumor microenvironment and induced an anti-tumor immune response, however, it was not sufficient for complete control of tumor metastasis.

CD28 Deficiency Ameliorates Blast Exposure-Induced Lung Inflammation, Oxidative Stress, Apoptosis, and T Cell Accumulation in the Lungs via the PI3K/Akt/FoxO1 Signaling Pathway

Although CD28 is associated with the expression of inflammatory mediators, apoptosis-related protein, immunosuppression, and tumorigenesis, the effects of CD28 deficiency on blast exposure-induced lung injury have not been investigated. In this study, we have explored the effects of CD28 on blast exposure-induced lung injury and studied its potential molecular mechanisms. A mouse model of blast exposure-induced acute lung injury was established. Sixty C57BL/6 wild-type (WT) and CD28 knockout (CD28^−/−) mice were randomly divided into control or model groups. Lung tissue samples were collected 24 h and 48 h after blast injury. Histopathological changes and the expressions of inflammatory-related proteins were detected by hematoxylin-eosin, immunohistochemistry, and immunofluorescence staining. Apoptosis and oxidative stress were evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and reactive oxygen species (ROS). Inflammation, apoptosis, oxidative stress, and related pathway protein expression were studied by western blotting. In addition, the levels of CD3 and CD28 proteins were measured by flow cytometry. In the current study, we found that CD28 deficiency significantly inhibited blast exposure-induced increases in the lung weight/body weight ratio and wet weight/dry weight ratio; decreased the infiltration of CD44⁺ leukocytes, CD163⁺ macrophages, and CD3⁺ T cells into the lungs; reduced the expressions of proinflammatory cytokines including IL-1β, TNF-α, and IL-6; and markedly increased IL-10 expression. CD28 deficiency also significantly attenuated blast exposure-induced ROS, MDA5, and IREα expressions; increased SOD-1 expression; lowered the number of apoptotic cells and Bax, Caspase-3, and active Caspase-8 expressions; and increased Bcl-2 expression. Additionally, CD28 deficiency significantly ameliorated blast exposure-induced increases of p-PI3K and p-Akt and ameliorated the decrease in the p-FoxO1 expression. Our results suggest that CD28 deficiency has a protective effect on blast exposure-induced lung injury, which might be associated with the PI3K/Akt/FoxO1 signaling pathway.

The value of cytokine levels in triage and risk prediction for women with persistent high-risk human papilloma virus infection of the cervix

Background

Cervical cancer is a common cancer among women worldwide and is closely related to high-risk human papillomavirus infection (HR-HPV). The immune microenvironment is thought to play an essential role in viral infection and cancer development; however, this relationship remains controversial. Cytokines are an important part of the immune system. Therefore, in this study, we explored changes in cervical cytokine levels of women with persistent HR-HPV infection and determined the value of cytokine detection in assessing cervical lesions.

Methods

We enrolled 146 patients; 117 had long-term high-risk (HR) HPV infection (> 6 months), and 29 were HPV-negative with previous HR-HPV infection. According to histopathological examination, 43 patients were diagnosed with cervicitis; 35, with low-grade squamous intraepithelial lesions (LSILs); and 39, with high-grade squamous intraepithelial lesions (HSILs). Cytokine levels in vaginal fluid were examined using cytometric bead array, and the values of interleukin (IL)-6 and IL-2 levels were converted to a cytokine score. The performance of the cytokine score for diagnosis and risk assessment was compared with that of ThinPrep cytology tests (TCTs).

Results

Disease severity was positively associated with IL-6 levels and inversely related to IL-2 levels. The area under the curve (AUC) was higher for the cytokine score including IL-6 and IL-2 than for TCTs for HSILs. Comparisons of the sensitivity, specificity, Youden index, and positive and negative predictive values for HSILs demonstrated that the cytokine score was better than TCT. HPV-positive patients with high cytokine scores showed increased risk of developing HSIL within 3 years. The hazard ratio for the cytokine score was 3.12; thus, the risk of developing HSIL was related to the cytokine score.

Conclusions

The cytokine score increased with the severity of cervical lesions and could distinguish more patients from HPV-positive women and predict the risk of disease progression.

Regulation of cancer immune escape: The roles of miRNAs in immune checkpoint proteins

Immune checkpoint proteins (ICPs) are regulators of immune system. The ICP dysregulation silences the host immune response to cancer-specific antigens, contributing to the occurrence and progress of various cancers. MiRNAs are regulatory molecules and function in mRNA silencing and post-transcriptional regulation of gene expression. MiRNAs that modulate the immunity via ICPs have received increasing attention. Many studies have shown that the expressions of ICPs are directly or indirectly repressed by miRNAs in multiple types of cancers. MiRNAs are also subject to regulation by ICPs. In this review, recent studies of the relationship between miRNAs and ICPs (including the PD-1, PD-L1, CTLA-4, ICOS, B7-1, B7-2, B7-H2, B7-H3, CD27, CD70, CD40, and CD40L) in cancer immune escape are comprehensively discussed, which provide critical detailed mechanistic insights into the functions of the miRNA-ICP axes and their effects on immune escape, and will be beneficial for the potential applications of immune checkpoint therapy and miRNA-based guidance for personalized medicine as well as for predicting the prognosis.

The NKG2D/NKG2DL Axis in the Crosstalk Between Lymphoid and Myeloid Cells in Health and Disease

Natural killer group 2, member D (NKG2D) receptor is a type II transmembrane protein expressed by both innate and adaptive immune cells, including natural killer (NK) cells, CD8+ T cells, invariant NKT cells, γδ T cells, and some CD4+ T cells under certain pathological conditions. NKG2D is an activating NK receptor that induces cytotoxicity and production of cytokines by effector cells and supports their proliferation and survival upon engagement with its ligands. In both innate and T cell populations, NKG2D can costimulate responses induced by other receptors, such as TCR in T cells or NKp46 in NK cells. NKG2D ligands (NKG2DLs) are remarkably diverse. Initially, NKG2DL expression was typically attributed to stressed, infected, or transformed cells, thus signaling “dysregulated-self.” However, many reports indicated their expression under homeostatic conditions, usually in the context of cell activation and/or proliferation. Myeloid cells, including macrophages and dendritic cells (DCs), are among the first cells sensing and responding to pathogens and tissue damage. By secreting a plethora of soluble mediators, by presenting antigens to T cells and by expressing costimulatory molecules, myeloid cells play vital roles in inducing and supporting responses of other immune cells in lymphoid organs and tissues. When activated, both macrophages and DCs upregulate NKG2DLs, thereby enabling them with additional mechanisms for regulating lymphocyte responses. In this review, we will focus on the expression of NKG2D by innate and adaptive lymphocytes, the regulation of NKG2DL expression on myeloid cells, and the contribution of the NKG2D/NKG2DL axis to the crosstalk of myeloid cells with NKG2D-expressing lymphocytes. In addition, we will highlight pathophysiological conditions associated with NKG2D/NKG2DL dysregulation and discuss the putative involvement of the NKG2D/NKG2DL axis in the lymphocyte/myeloid cell crosstalk in these diseases.

T- and NK-cell populations with regulatory phenotype and markers of apoptosis in circulating lymphocytes of patients with CIN3 or microcarcinoma of the cervix: evidence for potential mechanisms of immune suppression

BACKGROUND

Processes and mechanisms responsible for systemic immune suppression in early-stage cervical cancer remain substantially underinvestigated. In this work, we focused on studying the frequencies of circulating regulatory T (CD4 and CD8 Tregs) and NK (NKregs) cells in parallel with assessment of apoptotic markers expression in T cells from patients with preinvasive and microinvasive cervical cancer, with the aim to determine whether up-regulation of apoptosis-associated markers in Т lymphocytes accompanies cervical cancer development and correlates with the change in percentages of regulatory cell populations at systemic level during the initial stages of invasive cervical cancer progression.

METHODS

Fourty two women with histologically confirmed cervical intraepithelial neoplasia grade 3 (CIN3, including carcinoma in situ) or cervical cancer (stage IA) and 30 healthy women (control) were enrolled in the study. Peripheral blood samples were taken immediately before surgery or any treatment and immediately subjected to multicolor flow cytometry.

RESULTS

Analysis of a combination of CD4/CD8, CD25, CD127, and FoxP3 markers revealed a statistically significant increase in the frequencies of Tregs within both the CD4 and CD8 subsets of circulating lymphocytes in patients with CIN3 and stage IA cancer. In contrast, lower numbers of NKregs (defined as CD16^dim/negCD56^bright subpopulation) and increased CD56^dim/CD56^bright NK ratio were found in patients compared to controls, with the percentage of CD16^brightCD56^dim cells (major subtype of circulating NKs) showing no difference. Patients also exhibited an increased expression of CD95 in total peripheral blood T lymphocytes, along with increased level of Annexin V binding to CD95-positive cells, suggesting higher susceptibility of T cells to apoptosis and potential involvement of CD95-dependent pathway in early-stage cervical cancer. Differential analysis of CD4 and CD8 T cells revealed different trends in the change of CD95 expression, confirming that this change likely has different functional significance for these two subsets. A search for correlations between the phenotypic parameters analyzed in this study was performed to demonstrate that women with early neoplastic lesions of the cervix, such as carcinoma in situ and microinvasive carcinoma, displayed a coordinated increase in expression of Treg markers in circulating lymphocytes, along with more pronounced cross-relationships between Treg numbers, CD95 expression on T cells, and apoptosis, compared to the control group.

CONCLUSIONS

The results of this study suggest that a diversity of immune regulatory mechanisms that provide support for initial stages of invasive growth in cervical cancer patients includes systemic changes in the ratios between the principal regulatory and effector lymphocyte populations both within adaptive and innate immunity.