A High RORγT/CD3 Ratio is a Strong Prognostic Factor for Postoperative Survival in Advanced Colorectal Cancer: Analysis of Helper T Cell Lymphocytes (Th1, Th2, Th17 and Regulatory T Cells)

Cellular mechanisms of combining innate immunity activation with PD-1/PD-L1 blockade in treatment of colorectal cancer

PD-1/PD-L1 blockade therapies have displayed extraordinary clinical efficacy for melanoma, renal, bladder and lung cancer; however, only a minority of colorectal cancer (CRC) patients benefit from these treatments. The efficacy of PD-1/PD-L1 blockade in CRC is limited by the complexities of tumor microenvironment. PD-1/PD-L1 blockade immunotherapy is based on T cell-centered view of tumor immunity. However, the onset and maintenance of T cell responses and the development of long-lasting memory T cells depend on innate immune responses. Acknowledging the pivotal role of innate immunity in anti-tumor immune response, this review encapsulates the employment of combinational therapies those involve PD-1/PD-L1 blockade alongside the activation of innate immunity and explores the underlying cellular mechanisms, aiming to harnessing innate immune responses to induce long-lasting tumor control for CRC patients who received PD-1/PD-L1 blockade therapy.

Th17 cell function in cancers: immunosuppressive agents or anti-tumor allies?

T helper (Th) 17 cells, a distinct subset of Th lymphocytes, are known for their prominent interleukin (IL)-17 production and other pro-inflammatory cytokines. These cells exhibit remarkable plasticity, allowing them to exhibit different phenotypes in the cancer microenvironment. This adaptability enables Th17 cells to promote tumor progression by immunosuppressive activities and angiogenesis, but also mediate anti-tumor immune responses through employing immune cells in tumor setting or even by directly converting toward Th1 phenotype and producing interferon-gamma (IFN-γ). This dual role of Th17 cells in cancer makes it a double-edged sword in encountering cancer. In this review, we aim to elucidate the complexities of Th17 cell function in cancer by summarizing recent studies and, ultimately, to design novel therapeutic strategies, especially targeting Th17 cells in the tumor milieu, which could pave the way for more effective cancer treatments.

Rejuvenated iPSC-derived GD2-directed CART Cells Harbor Robust Cytotoxicity Against Small Cell Lung Cancer

Small cell lung cancer (SCLC) is exceptionally aggressive, with limited treatment options. Disialoganglioside (GD2) is highly expressed on SCLC and is considered a good target for chimeric antigen receptor (CAR) T cells (CART). Although GD2-directed CARTs (GD2-CART) exhibit cytotoxicity against various GD2-expressing tumors, they lack significant cytotoxicity against SCLC. To enhance cytotoxicity of GD2-CARTs against SCLC, we introduced GD2-CAR into induced pluripotent stem cells (iPSC)-derived rejuvenated cytotoxic T lymphocytes (GD2-CARrejT). GD2-CARrejTs acted much more strongly against SCLC cells than did GD2-CARTs both in vitro and in vivo. Single-cell RNA sequencing elucidated that levels of expression of TIGIT were significantly lower and levels of expression of genes associated with cytotoxicity were significantly higher in GD2-CARrejTs than those in GD2-CARTs. Dual blockade of TIGIT and programmed death-1 (PD-1) increased the cytotoxicity of GD2-CARTs to some extent, suggesting that low TIGIT and PD-1 expression by GD2-CARrejTs is a major factor required for robust cytotoxicity against SCLC. Not only for robust cytotoxicity but also for availability as "off-the-shelf" T-cell therapy, iPSC-derived GD2-CARrejTs are a promising novel treatment for SCLC.

SIGNIFICANCE

This research introduces iPSC-derived rejuvenated GD2-CARTs (GD2-CARrejT) as a novel approach to combat SCLC. Compared with conventional GD2-CARTs, GD2-CARrejTs with reduced TIGIT and PD-1 expression demonstrate robust cytotoxicity against SCLC and would be a promising therapy for SCLC.

Immune cell infiltrates in peritoneal metastases from colorectal cancer

Background

The presence of peritoneal metastases (PMs) in patients with colorectal cancer (CRC) confers a poor prognosis and only a minority of patients will benefit from the available treatment options. In primary CRC tumors, it is well established that a high infiltration of CD8+ effector T cells correlates to a favorable patient outcome. In contrast, the immune response induced in PMs from CRC and how it relates to patient survival is still unknown. In this study, we characterized the immune infiltrates and the distribution of immune checkpoint receptors on T cells from PMs from CRC, in order to evaluate the potential benefit of checkpoint blockade immunotherapy for this patient group.

Methods

Surgically resected PM tissue from CRC patients (n=22) and synchronous primary tumors (n=8) were processed fresh to single cell suspensions using enzymatic digestion. Surface markers and cytokine production were analyzed using flow cytometry.

Results

T cells dominated the leukocyte infiltrate in the PM specimens analyzed, followed by monocytes and B cells. Comparing two different PMs from the same patient usually showed a similar distribution of immune cells in both samples. The T cell infiltrate was characterized by an activated phenotype and markers of exhaustion were enriched compared with matched circulating T cells, in particular the checkpoint receptors PD-1 and TIGIT. In functional assays most cytotoxic and helper T cells produced INF-γ and TNF following polyclonal stimulation, while few produced IL-17, indicating a dominance of Th1-type responses in the microenvironment of PMs.

Conclusion

Immune cells were present in all PMs from CRC examined. Although infiltrating T cells express markers of exhaustion, they produce Th1-type cytokines when stimulated. These results indicate the possibility to augment tumor-specific immune responses within PMs using checkpoint blockade inhibitors.

Discovery, Synthesis, and In Vitro Characterization of 2,3 Derivatives of 4,5,6,7-Tetrahydro-Benzothiophene as Potent Modulators of Retinoic Acid Receptor-Related Orphan Receptor γt

Retinoic acid receptor-related orphan receptor γt (RORγt) is a nuclear receptor that is expressed in a variety of tissues and is a potential drug target for the treatment of inflammatory and auto-immune diseases, metabolic diseases, and resistant cancer types. We herein report the discovery of 2,3 derivatives of 4,5,6,7-tetrahydro-benzothiophene modulators of RORγt. We also report the solubility in acidic/neutral pH, mouse/human/dog/rat microsomal stability, Caco-2, and MDR1-MDCKII permeabilities of a set of these derivatives. For this group of modulators, inverse agonism by steric clashes and push-pull mechanisms induce greater instability to protein conformation compared to agonist lock hydration. Independent of the two mechanisms, we observed a basal modulatory activity of the tested 2,3 derivatives of 4,5,6,7-tetrahydro-benzothiophene toward RORγt due to the interactions with the Cys320-Glu326 and Arg364-Phe377 hydrophilic regions. The drug discovery approach reported in the current study can be employed to discover modulators of nuclear receptors and other globular protein targets.

Prognostic impact of the post-treatment T cell composition and spatial organization in soft tissue sarcoma patients treated with neoadjuvant hyperthermic radio(chemo)therapy

Soft tissue sarcomas (STS) form a heterogeneous group of tumors sharing a mesenchymal origin. Despite good local control of the disease, the occurrence of distant metastases often limits survival of STS patients with localized, high-risk tumors of the extremities. Accumulating evidence suggests a central role for the tumor immune microenvironment in determining the clinical outcome and response to therapy. Thus, it has been reported that STS patients with a high immune signature and especially presence of B cells and tertiary lymphoid structures display improved overall survival and response to checkpoint inhibitor treatment. Here, we explored the effect of curative multimodal therapy on the T cell landscape of STS using multiplex immunohistochemistry. We analyzed the phenotype, frequency, and spatial distribution of STS-infiltrating CD8+ T cells by staining for CD8, 4-1BB, Granzyme B, Ki67, PD-1, and LAG-3 as well as CD3+ T helper cells using a panel consisting of CD3, T-bet, GATA3, RORγT, FoxP3, and Ki67. All patients received neoadjuvant radiotherapy plus locoregional hyperthermia with or without chemotherapy. While the treatment-naïve biopsy sample allows an analysis of baseline T cell infiltration levels, both intra- and peritumoral areas of the matched resected tissue were analyzed to assess composition and spatial distribution of the T cell compartment and its therapeutic modulation. Generally, post-treatment tissues displayed lower frequencies of CD3+ and CD8+ T cells. Association with clinical data revealed that higher post-treatment frequencies of peritumoral and intratumoral CD3+ T cells and intratumoral PD-1+ CD8+ T cells were significantly associated with improved disease-free survival (DFS), while these densities had no prognostic significance in the biopsy. Upon spatial analysis, a high ratio of intratumoral to peritumoral CD8+ T cells emerged as an independent prognostic marker for longer DFS. These results indicate that the STS T cell landscape is altered by multimodal therapy and may influence the clinical outcome of patients. An enhanced understanding of the STS immune architecture and its modulation by neoadjuvant therapy may pave the way towards novel treatment modalities and improve the long-term clinical outcome of STS patients.

Analysis of Circulating Immune Subsets in Primary Colorectal Cancer

The development and progression of colorectal cancer (CRC) are known to be affected by the interplay between tumor and immune cells. However, the impact of CRC cells on the systemic immunity has yet to be elucidated. We aimed to comprehensively evaluate the circulating immune subsets and transcriptional profiles of CRC patients. In contrast to healthy controls (HCs), CRC patients had a lower percentage of B and T lymphocytes, T helper (Th) cells, non-classical monocytes, dendritic cells, and a higher proportion of polymorphonuclear myeloid-derived suppressor cells, as well as a reduced expression of CD69 on NK cells. Therefore, CRC patients exhibit a more evident systemic immune suppression than HCs. A diagnostic model integrating seven immune subsets was constructed to distinguish CRC patients from HCs with an AUC of 1.000. Moreover, NR3C2, CAMK4, and TRAT1 were identified as candidate genes regulating the number of Th cells in CRC patients. The altered composition of circulating immune cells in CRC could complement the regional immune status of the tumor microenvironment and contribute to the discovery of immune-related biomarkers for the diagnosis of CRC.

Extensive Phenotypic Characterization of T Cells Infiltrating Liver Metastasis from Colorectal Cancer: A Potential Role in Precision Medicine

Colorectal cancer (CRC) is one of the most common cancers worldwide, with liver metastasis being its main cause of death. This study harvested fresh biological material from non-tumor and tumor tissue from 47 patients with CRC liver metastasis after surgery, followed by mechanical cellular extraction and stain-lyse-wash direct immunofluorescence technique. Here, 60 different T-cell populations were characterized by flow cytometry. Tumor samples were also subdivided according to their growth pattern into desmoplastic and non-desmoplastic. When we compared tumor versus non-tumor samples, we observed a significantly lower percentage of T-lymphocyte infiltration in the tumor in which the CD4⁺ T-cell density increased compared to the CD8⁺ T cells. T regulatory cells also increased within the tumor, even with an activated phenotype (HLA-DR⁺). A higher percentage of IL-17-producing cells was present in tumor samples and correlated with the metastasis size. In contrast, we also observed a significant increase in CD8⁺ follicular-like T cells (CD185⁺), suggesting a cytotoxic response to cancer cells. Additionally, most infiltrated T cells exhibit an intermediate activation phenotype (CD25⁺). In conclusion, our results revealed potential new targets and prognostic biomarkers that could take part in an algorithm for personalized medicine approaches improving CRC patients' outcomes.

Construction of a Prognostic Evaluation Model for Stomach Adenocarcinoma on the Basis of Immune-Related lncRNAs

Progression, prognosis, and therapeutic strategy of stomach adenocarcinoma (STAD) have a close connection with tumor microenvironment (TME). Thus, it is pivotal to delve into the TME and immune-related genes, which may bring possibilities for improving patient's prognosis. TCGA-STAD dataset was analyzed to acquire differentially expressed lncRNAs in tumor samples, which were overlapped with the immune-related lncRNA datasets in the ImmLnc database. Twenty-six lncRNAs related to STAD immunity and patient's prognosis were acquired by univariate Cox analysis. Following lncRNA expression patterns, STAD samples could be classified into two clusters with completely different immune patterns. We performed multivariate Cox regression analysis on lncRNAs to identify 7-feature lncRNAs and constructed a corresponding prognostic model. The model validity was verified by survival analysis and ROC curve in validation and training sets. To explore connection between model and TME and tumor drug resistance, this study analyzed differences in immune cell infiltration between samples from high- and low-risk groups and then revealed immune cells follicular helper with significant differences in tumor tissue infiltration. Analysis of resistance to chemotherapeutic drugs revealed that samples in the high-risk group had resistance to cisplatin, doxorubicin, bleomycin, and gemcitabine. Through univariate and multivariate Cox analyses, we manifested that risk score could be an independent prognostic factor. Combining risk score and clinical factors, a nomogram was constructed to accurately predict patient's prognosis. This model can effectively predict prognosis, TME, and drug resistance of STAD patients, which may provide a reference for tumor development evaluation and precise treatment for clinical STAD.

Targeting interleukin-17 enhances tumor response to immune checkpoint inhibitors in colorectal cancer

Although immune checkpoint inhibitors (ICIs) have gained much attention in managing cancer, only a minority of patients, especially those with tumors that have been classified as immunologically "cold" such as microsatellite stable (MSS) colorectal cancers (CRC), experience clinical benefit from ICIs. Surprisingly, interleukin-17 (IL-17) and its primary source Th17 are enriched in CRC and inversely associated with patient outcome. Our previous study revealed that IL-17A could upregulate programmed death-ligand 1 (PD-L1) expression and impede the efficacy of immunotherapy. IL-17, therefore, can be a possible target to sensitize tumor cells to ICIs. The detailed clinical results from our trial, which is the first to show the benefits of the combination of anti-PD-1 with anti-IL-17 therapy for MSS CRC, have also been presented. In this review, we highlight the role of IL-17 in ICIs resistance and summarize the current clinical evidence for the use of combination therapy. Directions for future strategies to warm up immunologically "cold" MSS CRCs have also been proposed.

MicroRNA-766-3p-mediated downregulation of HNF4G inhibits proliferation in colorectal cancer cells through the PI3K/AKT pathway

Nuclear receptors (NRs) are a class of transcription factors that play a pivotal role in carcinogenesis, but their function in colorectal cancer (CRC) remains unclear. Here, we investigate the role NRs play in CRC pathogenesis. We found that hepatocyte nuclear factor 4 gamma (HNF4G; NR2A2), hepatocyte nuclear factor 4α (HNF4A; NR2A1), and retinoid-related orphan receptor γ (RORC; NR1F3) were significantly upregulated in CRC tissues analyzed by GEPIA bioinformatics tool. The expression of HNF4G was examined in CRC samples and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Increased expression of HNF4G was strongly associated with high tumor-node-metastasis stage and poor prognosis. Moreover, overexpression of HNF4G significantly promoted the proliferation of CRC cells in vitro. Next, we found that HNF4G promoted CRC proliferation via the PI3K/AKT pathway through targeting of GNG12 and PTK2. In addition, HNF4G was verified as a direct target of microRNA-766-3p (miR-766-3p). miR-766-3p inhibited the proliferation of CRC cells by targeting HNF4G in vitro and in vivo. Collectively, our study indicates that miR-766-3p reduces the proliferation of CRC cells by targeting HNF4G expression and thus inhibits the PI3K/AKT pathway. Therefore, development of therapies which target the miR-766-3p/HNF4G axis may aid in the treatment of CRC.

Correlation and prognostic implications of intratumor and tumor draining lymph node Foxp3+ T regulatory cells in colorectal cancer

BACKGROUND

The prognostic value of intratumor T regulatory cells (Tregs) in colorectal cancer (CRC) was previously reported, but the role of these cells in tumor draining lymph nodes (TDLNs) was less addressed.

METHODS

A total of 150 CRC stages I-IV were retrospectively enrolled. Intratumor and TDLN Tregs were examined by immunohistochemical assay. The association of these cells was estimated by Pearson correlation. Survival analyses of subgroups were conducted by Kaplan-Meier curves, and the log-rank test and risk factors for survival were tested by the Cox proportional hazard model.

RESULTS

High accumulation of Tregs in tumors was significant in patients with younger age and good histological grade, where enrichment of these cells in TDLNs was more apparent in those with node-negative disease and early TNM stage disease, both of which were more common in early T stage cases. A significant correlation of intratumoral and TDLN Tregs was detected. Patients with higher intratumoral Tregs displayed significantly better PFS and OS than those with lower Tregs. However, no such differences were found, but a similar prognostic prediction trend was found for these cells in TDLNs. Finally, intratumoral Tregs were an independent prognostic factor for both PFS (HR = 0.97, 95% CI 0.95-0.99, P < 0.01) and OS (HR = 0.98, 95% CI 0.95-1.00, P = 0.04) in the patients.

CONCLUSIONS

Higher intratumor Tregs were associated with better survival in CRC. Although no such role was found for these cells in TDLNs, the positive correlation and similar prognostic prediction trend with their intratumoral counterparts may indicate a parallelized function of these cells in CRC.

Multifaceted functions of chronic inflammation in regulating tumor dormancy and relapse

Inflammation is a double-edged sword exhibiting multifaceted functions. On one hand, it either induces tumor cell apoptosis, or establishes tumor dormancy by inhibiting tumor cell proliferation; on the other hand, it either facilitates the tumorigenesis process or reawakens dormant tumor cells, resulting in disease recurrences. Each outcome would depend on the balance between type I and type II inflammation as well as the duration of inflammation being acute or chronic. In this essay, we provide a critical review of the empirical evidence suggesting that chronic inflammation, dominated by type I inflammatory cells and cytokines as a result of trauma and microbiome dysbiosis, could facilitate the carcinogenesis process in normal cells and retain nascent transformed cells in a dormant state. On the other hand, an elevated type II inflammation along with inefficient resolution of type I inflammation following trauma or major surgeries could delay the wound healing process and promote the growth and reawakening of dormant tumor cells, resulting in disease recurrences. Finally, cytokines exhibiting type I and II inflammatory functions, simultaneously, tend to promote tumor recurrence when become chronic. Therefore, the risk of reawakening dormant tumor cells should be considered in cancer survivors who experience major surgeries and trauma, or suffer from chronic inflammatory diseases.

iPSC-Derived Neoantigen-Specific CTL Therapy for Ewing Sarcoma

The prognosis of Ewing sarcoma caused by EWS/FLI1 fusion is poor, especially after metastasis. Although therapy with CTLs targeted against altered EWS/FLI1 sequences at the gene break/fusion site may be effective, CTLs generated from peripheral blood are often exhausted because of continuous exposure to tumor antigens. We addressed this by generating induced pluripotent stem cell (iPSC)-derived functionally rejuvenated CTLs (rejT) directed against the neoantigen encoded by the EWS/FLI1 fusion gene. In this study, we examined the antitumor effects of EWS/FLI1-rejTs against Ewing sarcoma. The altered amino acid sequence at the break/fusion point of EWS/FLI1, when presented as a neoantigen, evokes an immune response that targets EWS/FLI1 ⁺ sarcoma. Although the frequency of generated EWS/FLI1-specific CTLs was only 0.003%, we successfully established CTL clones from a healthy donor. We established iPSCs from a EWS/FLI1-specific CTL clone and redifferentiated them into EWS/FLI1-specific rejTs. To evaluate cytotoxicity, we cocultured EWS/FLI1-rejTs with Ewing sarcoma cell lines. EWS/FLI1-rejTs rapidly and continuously suppressed the proliferation of Ewing sarcoma for >40 hours. Using a Ewing sarcoma xenograft mouse model, we verified the antitumor effect of EWS/FLI1-rejTs via imaging, and EWS/FLI1-rejTs conferred a statistically significant survival advantage. "Off-the-shelf" therapy is less destructive and disruptive than chemotherapy, and radiation is always desirable, particularly in adolescents, whom Ewing sarcoma most often affects. Thus, EWS/FLI1-rejTs targeting a Ewing sarcoma neoantigen could be a promising new therapeutic tool.

Preinvasive Colorectal Lesions of African Americans Display an Immunosuppressive Signature Compared to Caucasian Americans

BACKGROUND

African Americans (AAs) have higher colorectal cancer (CRC) incidence and mortality rate than Caucasian Americans (CAs). Recent studies suggest that immune responses within CRCs contribute to the disparities. If racially distinct immune signatures are present in the early phases of carcinogenesis, they could be used to develop interventions to prevent or slow disease.

METHODS

We selected a convenience sample of 95 patients (48 CAs, 47 AAs) with preinvasive colorectal adenomas from the surgical pathology laboratory at the Medical University of South Carolina. Using immunofluorescent-conjugated antibodies on tissue slides from the lesions, we quantified specific immune cell populations: mast cells (CD117+), Th17 cells (CD4+RORC+), and NK cell ligand (MICA/B) and inflammatory cytokines, including IL-6, IL-17A, and IFN-γ. We compared the mean density counts (MDCs) and density rate ratios (RR) and 95% CI of immune markers between AAs to CAs using negative binomial regression analysis. We adjusted our models for age, sex, clinicopathologic characteristics (histology, location, dysplasia), and batch.

RESULTS

We observed no racial differences in age or sex at the baseline endoscopic exam. AAs compared to CAs had a higher prevalence of proximal adenomas (66% vs. 40%) and a lower prevalence of rectal adenomas (11% vs. 23%) (p =0.04) but no other differences in pathologic characteristics. In age, sex, and batch adjusted models, AAs vs. CAs had lower RRs for cells labeled with IFNγ (RR 0.50 (95% CI 0.32-0.81); p=0.004) and NK cell ligand (RR 0.67 (0.43-1.04); p=0.07). In models adjusted for age, sex, and clinicopathologic variables, AAs had reduced RRs relative to CAs for CD4 (p=0.02), NK cell ligands (p=0.01), Th17 (p=0.005), mast cells (p=0.04) and IFN-γ (p< 0.0001).

CONCLUSIONS

Overall, the lower RRs in AAs vs. CAs suggests reduced effector response capacity and an immunosuppressive ('cold') tumor environment. Our results also highlight the importance of colonic location of adenoma in influencing these differences; the reduced immune responses in AAs relative to CAs may indicate impaired immune surveillance in early carcinogenesis. Future studies are needed to understand the role of risk factors (such as obesity) in influencing differences in immune responses by race.

Distribution of Regulatory T-Cells and Other Phenotypes of T-Cells in Tumors and Regional Lymph Nodes of Colorectal Cancer Patients

BACKGROUND/AIM

Tumor microenvironments consist of many types of immune cells, in which regulatory T-cells (Tregs) are supposed to play important roles to suppress anti-tumor immunity. Regional lymph nodes are essential for antitumor immunity in colorectal cancer (CRC). In this study, we compared the diversity of phenotypes of T-cells in normal tissue and regional lymph nodes in order to determine the immunosuppressive mechanism of lymph node metastasis of CRC.

PATIENTS AND METHODS

Fifty patients were enrolled in this study, and paired samples (tumor tissue, normal tissue, and three regional lymph node samples and as well as non-regional lymph node samples) were obtained from each patient. In each paired-sample set, the proportions of different immune cell types and T-cells expressing immune checkpoint molecules were compared using flow cytometry.

RESULTS

Higher proportions of Tregs [7.58% (4.94%-13.87%) vs. 1.79% (0.03%-5.36%), p<0.001] and lower proportions of INFγ-producing CD4-positive T (iCD4+) cells [21.49% (12.08%-27.35%) vs. 26.55% (15.65%-37.63%), p<0.001] were observed in tumor tissue than in normal mucosa. Parts of regional lymph nodes nearest the tumor had a greater proportion of Tregs [5.86% (4.18%-7.69%)] and lower proportions of iCD4+ [5.94% (3.51%-9.04%)] and INFγ-producing CD8-positive T (iCD8+) cells [21.93% (14.92%-35.90%)] than distant parts of regional lymph nodes and non-regional lymph nodes. Both immune-suppressing molecules (CTLA-4 and PD-1) and immune-promoting molecules (OX-40 and ICOS) tended to be highly expressed in tumor tissue and local lymph nodes.

CONCLUSION

In patients with CRC, regional lymph nodes, especially the parts nearest the tumor, had a higher proportion of Tregs and other suppressive immunophenotypes of T-cells than those located more distantly.

IRF1-mediated immune cell infiltration is associated with metastasis in colon adenocarcinoma

BACKGROUND

Evidence suggests that metastasis is chiefly responsible for the poor prognosis of colon adenocarcinoma (COAD). The tumor microenvironment plays a vital role in regulating this biological process. However, the mechanisms involved remain unclear. The aim of this study was to identify crucial metastasis-related biomarkers in the tumor microenvironment and investigate its association with tumor-infiltrating immune cells.

METHODS

We obtained gene expression profiles and clinical information from The Cancer Genome Atlas database. According to the "Estimation of STromal and Immune cells in MAlignant Tumor tissue using Expression data" algorithm, each sample generated the immune and stromal scores. Following correlation analysis, the metastasis-related gene was identified in The Cancer Genome Atlas database and validated in the GSE40967 dataset from Gene Expression Omnibus. The correlation between metastasis-related gene and infiltrating immune cells was assessed using the Tumor IMmune Estimation Resource database.

RESULTS

The analysis included 332 patients; the metastatic COAD samples showed a low immune score. Correlation analysis results showed that interferon regulatory factor 1 (IRF1) was associated with tumor stage, lymph node metastasis, and distant metastasis. Furthermore, significant associations between IRF1 and CD8+ T cells, T cell (general), dendritic cells, T-helper 1 cells, and T cell exhaustion were demonstrated by Spearmans correlation coefficients and P values.

CONCLUSIONS

The present findings suggest that IRF1 is associated with metastasis and the degree of immune infiltration of CD8+ T cells (general), dendritic cells, T-helper 1 cells, and T cell exhaustion in COAD. These results may provide information for immunotherapy in colon cancer.

PD-1/PD-L1 axis importance and tumor microenvironment immune cells

Triple-negative breast cancer (TNBC) is heterogeneous cancer with poor prognosis among the other breast tumors. Rapid recurrence and increased progression rate could be reasons for the poor prognosis of this type of breast cancer. Recently, because of the lack of specific targets in multiple cancer treatment, immune checkpoint blockade therapies with targeting PD-1/PD-L1 axis have displayed significant advances and improved survival. Among different types of breast cancers, TNBC is considered more immunogenic with high T-cell and other immune cells infiltration compared to other breast cancer subtypes. This immunogenic characteristic of TNBC is a beneficial marker in the immunotherapy of these tumors. Clinical studies with a focus on immune checkpoint therapy have demonstrated promising results in TNBC treatment. In this review, we summarize clinical trials with the immunotherapy-based treatment of different cancers and also discuss the interaction between infiltrating immune cells and breast tumor microenvironment. In addition, we focus on the signaling pathway that controls PD-L1 expression and continues with CAR T-cell therapy and siRNA as novel strategies and potential tools in targeted therapy.

Interactions of Segmented Filamentous Bacteria (Candidatus Savagella) and bacterial drivers in colitis-associated colorectal cancer development

Colorectal cancer (CRC) risk is influenced by host genetics, sex, and the gut microbiota. Using a genetically susceptible mouse model of CRC induced via inoculation with pathobiont Helicobacter spp. and demonstrating variable tumor incidence, we tested the ability of the Th17-enhancing commensal Candidatus Savagella, more commonly denoted as Segmented Filamentous Bacteria (SFB), to influence the incidence and severity of colitis-associated CRC in male and female mice. To document the composition of the gut microbiota during CRC development and identify taxa associated with disease, fecal samples were collected before and throughout disease development and characterized via 16S rRNA sequencing. While there were no significant SFB-dependent effects on disease incidence or severity, SFB was found to exert a sex-dependent protective effect in male mice. Furthermore, SFB stabilized the GM against Helicobacter-induced changes post-inoculation, resulting in a shift in disease association from Helicobacter spp. to Escherichia coli. These data support sex-dependent SFB-mediated effects on CRC risk, and highlight the complex community dynamics within the GM during exposure to inflammatory pathobionts.

Differences in the immunosurveillance pattern associated with DNA mismatch repair status between right-sided and left-sided colorectal cancer

Tumor location and immunity play important roles in the progression of colorectal cancer (CRC). This study aimed to investigate the differences in the immunosurveillance pattern between right‐ and left‐sided CRC and analyze their association with clinicopathologic features, including mismatch repair (MMR) status. We included surgically resected stage II/III CRC cases and evaluated the immunohistochemical findings of HLA class I, HLA class II, programmed cell death‐ligand 1 (PD‐L1), PD‐1, CTLA‐4, CD3, CD4, CD8, TIA‐1, T‐bet, GATA3, RORγT, Foxp3, and CD163. A total of 117 patients were included in the analyses; of these, 30 and 87 had right‐ and left‐sided cancer, respectively. Tumor immunity varied according to the tumor location in the overall cohort. Analysis of the tumors excluding those with DNA mismatch repair (MMR) deficiency also revealed that tumor immunity differed according to the tumor location. In right‐sided colon cancer (CC), high expression of Foxp3 (P = .0055) and TIA‐1 (P = .0396) were associated with significantly better disease‐free survival (DFS). High CD8 (P = .0808) and CD3 (P = .0863) expression tended to have better DFS. Furthermore, in left‐sided CRC, only high PD‐L1 expression in the stroma (P = .0426) was associated with better DFS. In multivariate analysis, high Foxp3 expression in right‐sided CC was an independent prognostic factor for DFS (hazard ratio, 7.6445; 95% confidence interval, 1.2091‐150.35; P = .0284). In conclusion, the immunosurveillance pattern differs between right‐ and left‐sided CRC, even after adjusting for MMR deficiency.

Enhancing the Value of Histopathological Assessment of Allograft Biopsy Monitoring

Traditional histopathological allograft biopsy evaluation provides, within hours, diagnoses, prognostic information, and mechanistic insights into disease processes. However, proponents of an array of alternative monitoring platforms, broadly classified as "invasive" or "noninvasive" depending on whether allograft tissue is needed, question the value proposition of tissue histopathology. The authors explore the pros and cons of current analytical methods relative to the value of traditional and illustrate advancements of next-generation histopathological evaluation of tissue biopsies. We describe the continuing value of traditional histopathological tissue assessment and "next-generation pathology (NGP)," broadly defined as staining/labeling techniques coupled with digital imaging and automated image analysis. Noninvasive imaging and fluid (blood and urine) analyses promote low-risk, global organ assessment, and "molecular" data output, respectively; invasive alternatives promote objective, "mechanistic" insights by creating gene lists with variably increased/decreased expression compared with steady state/baseline. Proponents of alternative approaches contrast their preferred methods with traditional histopathology and: (1) fail to cite the main value of traditional and NGP-retention of spatial and inferred temporal context available for innumerable objective analyses and (2) belie an unfamiliarity with the impact of advances in imaging and software-guided analytics on emerging histopathology practices. Illustrative NGP examples demonstrate the value of multidimensional data that preserve tissue-based spatial and temporal contexts. We outline a path forward for clinical NGP implementation where "software-assisted sign-out" will enable pathologists to conduct objective analyses that can be incorporated into their final reports and improve patient care.

Distinct functions and prognostic values of RORs in gastric cancer

Retinoic acid receptor-related orphan receptors (RORs) are frequently abnormally expressed in several human malignancies, including gastric cancer (GC). RORs are involved in the development and progression of GC through Wnt signaling pathway receptors and other common receptors. However, the prognostic roles of individual RORs in patients with GC remain elusive. We accessed the prognostic roles of three RORs (RORα, RORβ, and RORγ) through "The Kaplan-Meier plotter" (KM plotter) database in patients with GC. For all patients with GC who were followed for 20 years, the low mRNA expression of all three RORs showed a significant correlation with better outcomes. We further accessed the prognostic value of individual RORs in different clinical pathological features including Lauren classification, clinical stages, pathological grades, HER2 status, and different treatments methods. The RORs demonstrated critical prognostic roles in GC. Expressions of RORs were higher in GC tissues when compared with normal gastric tissues. Moreover, knockdown of RORs significantly inhibited cell proliferation and migration, suggesting an oncogenic role of RORs in human GC. These findings suggest potential roles of RORs as biomarkers for GC prognosis and as oncogenes in GC.

Synchronous nodal metastatic risk in screening detected and endoscopically removed pT1 colorectal cancers

BACKGROUND

The population screening campaigns have resulted in increasing the prevalence of endoscopically resected colorectal cancers (CRCs) invading the submucosa (pT1). Synchronous nodal involvement occurs in less than 15 % of these tumors. Histologic criteria currently used for selecting patients needing resection are imprecise and most patients could have been simply followed-up. Tumor infiltrating lymphocytes (TILs) and mismatch repair (MMR) status impact on CRC prognosis. To identify patients requiring completion surgery, the value of histologic variables, TILs and MMR status as risk factors of nodal metastasis was investigated in screening detected and endoscopically removed pT1 CRCs.

METHODS

In 102 endoscopically resected pT1 CRCs, the cancer phenotype, CD3+ and CD8+ TILs, and MMR status were assessed. Univariate and multivariate analyses were used to evaluate the correlation with nodal metastasis.

RESULTS

Positive resection margin, evidence of vascular invasion and tumor budding, wide area of submucosal invasion, and high number of CD3+ TILs were associated with nodal metastasis in univariate analyses. Vascular invasion was statistically independent in multivariate analysis. Evidence of neoplastic cells in the vessels and/or at the excision border featured 5 out of 5 metastatic tumors and 13 out of 97 non-metastatic ones.

CONCLUSIONS

Completion surgery should be recommended only in pT1 CRC with vascular invasion or with tumor cells reaching the margin. In all other cases, the treatment choice should result from a multidisciplinary discussion on the patient-centered evaluation of the risk-benefit ratio.

The Fate of Th17 Cells is Shaped by Epigenetic Modifications and Remodeled by the Tumor Microenvironment

Th17 cells represent a subset of CD4+ T cells characterized by the master transcription factor RORγt and the production of IL-17. Epigenetic modifications such as post-translational histone modifications and DNA methylation play a key role in Th17 cell differentiation and high plasticity. Th17 cells are highly recruited in many types of cancer and can be associated with good or bad prognosis. Here, we will review the remodeling of the epigenome induced by the tumor microenvironment, which may explain Th17 cell predominance. We will also discuss the promising treatment perspectives of molecules targeting epigenetic enzymes to remodel a Th17-enriched tumor microenvironment.

Immune Cell Infiltration in the Microenvironment of Liver Oligometastasis from Colorectal Cancer: Intratumoural CD8/CD3 Ratio Is a Valuable Prognostic Index for Patients Undergoing Liver Metastasectomy

Background: A comprehensive investigation into immune cell infiltration provides more accurate and reliable prognostic information for patients with colorectal liver oligometastases (CLO) after liver metastasectomy. Methods: Simultaneous detection of the immune constituents CD3⁺, CD8⁺, Foxp3⁺ T, and α-SMA⁺ cells in the liver oligometastasis of 133 patients was conducted using a four-colour immunohistochemical multiplex technique. Immune cells were quantified, and tumour-infiltrating lymphocyte (TIL) ratios were subsequently calculated. Correlation analysis was performed using Pearson’s correlation. Recurrence-free survival (RFS) and overall survival (OS) for TIL ratios were analysed using the Kaplan–Meier method and Cox regression models. Results: Significantly fewer CD3⁺, CD8⁺, and Foxp3⁺ T cells were observed in the intratumoural region than in the peritumoural region of liver metastases. CD3⁺, CD8⁺, Foxp3⁺ T, and α-SMA⁺ cells showed significantly positive correlations with each other both in the intratumoural and peritumoural regions of liver metastases. Only the CD8/CD3 TIL ratio demonstrated a positive correlation between intratumoural and peritumoural regions of liver metastases (r = 0.541, p < 0.001). Patients with high intratumoural CD8/CD3 ratios had significantly longer 3-year RFS (59.0% vs. 47.4%, p = 0.035) and 3-year OS rates (83.3% vs. 65.8%, p = 0.007) than those with low intratumoural CD8/CD3 ratios. Multivariate analyses revealed that the intratumoural CD8/CD3 ratio was independently associated with RFS (HR = 0.593; 95% CI = 0.357–0.985; p = 0.043) and OS (HR = 0.391; 95% CI = 0.193–0.794; p = 0.009). Conclusion: These findings offer a better understanding of the prognostic value of immune cell infiltration on liver oligometastasis from colorectal cancer.

Mesenchymal Stem Cell Administration Attenuates Colon Cancer Progression by Modulating the Immune Component within the Colorectal Tumor Microenvironment

We here determine the influence of mesenchymal stem cell (MSC) therapy on the progression of solid tumors. The influence of MSCs was investigated in human colorectal cancer cells as well as in an immunocompetent rat model of colorectal carcinogenesis representative of the human pathology. Treatment with bone marrow (BM)‐derived MSCs significantly reduced both cancer initiation and cancer progression by increasing the number of tumor‐free animals as well as decreasing the number and the size of the tumors by half, thereby extending their lifespan. The attenuation of cancer progression was mediated by the capacity of the MSCs to modulate the immune component. Specifically, in the adenocarcinomas (ADKs) of MSC‐treated rats, the infiltration of CD68+ monocytes/macrophages was 50% less while the presence of CD3+ lymphocytes increased almost twofold. The MSCs reprogrammed the macrophages to become regulatory cells involved in phagocytosis thereby inhibiting the production of proinflammatory cytokines. Furthermore, the MSCs decreased NK (Natural Killer) and rTh17 cell activities, Treg recruitment, the presence of CD8+ lymphocytes and endothelial cells while restoring Th17 cell activity. The expression of miR‐150 and miR‐7 increased up to fivefold indicating a likely role for these miRNAs in the modulation of tumor growth. Importantly, MSC administration limited the damage of healthy tissues and attenuated tumor growth following radiotherapy. Taken together, we here show that that MSCs have durable action on colon cancer development by modulating the immune component of the tumor microenvironment. In addition, we identify two miRNAs associated with the capacity of MSCs to attenuate cancer growth. stem cells translational medicine2019;8:285&300

Th17 cells over 5.9% at admission indicate poor prognosis in patients with HBV-related acute-on-chronic liver failure

Our previous study demonstrated that Th17 cells increased significantly in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). However, their prognostic role in HBV-ACLF patients remains unknown.Sixty-eight consecutive HBV-ACLF patients were enrolled in this cohort study. Th17 cells were examined using flow cytometry. Disease severity scores were assessed. ROC curves were used to evaluate the value in predicting prognosis. Survival was analyzed using Kaplan-Meier curves. Predictors of mortality were determined by regression analysis.Th17 cells were significantly higher in HBV-ACLF patients compared to patients with chronic hepatitis B and normal controls (both P < .001). Also, Th17 cells were higher in nonsurviving HBV-ACLF patients than in surviving patients (P = .014). Th17 cells were positively correlated with CLIF-Consortium ACLF (CLIF-C ACLF) score (r = 0.240, P = .048). ROC curves showed that the frequency of Th17 cells had accuracy in predicting 90-day prognosis equivalent to MELD, MELD-Na and CLIF-C ACLF scores in HBV-ACLF (P = .34, P = .26, and P = .15, respectively). More importantly, the area under the ROC curve (AUROC) increased when Th17 cells were combined with MELD, MELD-Na or CLIF-C ACLF score than using Th17 cells alone (P = .021, P = .006, and P = .023, respectively). Kaplan-Meier analysis revealed that higher Th17 cells (≥5.9%) were closely associated with poor overall survival in HBV-ACLF (P = .0086). Additionally, multivariate regression analysis showed that the frequency of Th17 cells over 5.9% was an independent predictor of mortality (OR = 0.154, P = .025).Circulating Th17 cells positively correlated with disease severity in HBV-ACLF. The frequency of Th17 cells over 5.9% could serve as a prognostic biomarker for HBV-ACLF patients.

Expression of Th17/Treg related molecules in gastric cancer tissues

BACKGROUND/AIMS

The function of regulatory T cells (Treg) and helper T cells 17 (Th17) related indexes, such as interleukin (IL)-6, IL-17, transforming growth factor (TGF)-β1, and forkhead box protein 3(FoxP3) in gastric adenocarcinoma tissues remains undefined. We investigated and analyzed the relevance of the proteins with the clinicopathological characteristics and the interactions among them in gastric cancer.

MATERIALS AND METHODS

A total 68 gastric cancer patients and 40 healthy controls were enrolled. Immunohistochemistry (IHC) as well as quantitative real-time reverse transcription- polymerase chain reaction (RT-PCR) was used to determine the expression levels of IL-6, TGF-β1, IL-17, and FoxP3 in the prepared tissues. Statistical analysis included ANOVA and chi-square test.

RESULTS

The expression levels of IL-6, IL-17, FoxP3, and TGF-β1 had significantly increased in cancer tissues compared to controls. Clinical staging of gastric cancer were correlated with the rise of IL-6, IL-17, FoxP3, and TGF-β1 levels expressed in cancer tissues. The expression level of TGF-β1 and IL-6 was positively related to that of IL-17 and FoxP3, similar to FoxP3 and IL-17 in gastric cancer tissues.

CONCLUSION

IL-6, TGF-β1, FoxP3, and IL-17 may promote the progression of gastric cancer individually or jointly and have complex interactions.

Association of interleukin-17A polymorphisms with the risk of colorectal cancer: A case-control study

BACKGROUND

Interleukin (IL)-17A is proinflammatory cytokine produced by Th17 cells, which play key, but sometimes inconsistent role in autoimmunity and cancer. Polymorphic variants in IL-17A gene were differentially associated with susceptibility to cancer, including colorectal cancer (CRC).

AIM

We investigated the association between six IL-17A gene variants (rs3819024, rs2275913, rs3819025, rs10484879, rs7747909, and rs3748067) with CRC susceptibility in Tunisians.

SUBJECTS AND METHODS

Retrospective case-control study. Study subjects comprised 293 patients with CRC, and 268 age-, gender-, and BMI-matched healthy controls. IL-17A genotyping was done by real-time PCR, with defined clusters.

RESULTS

Of the seven tested IL-17A tag-SNPs, minor allele frequency (MAF) of rs10484879 was significantly higher in CRC patients than control subjects. Heterozygous rs10484879 [OR (95% CI) = 2.63 (1.64-4.21)] was associated with higher risk, while carriage of heterozygous rs3748067 genotype was associated with reduced risk of CRC [OR (95% CI) = 0.56 (0.37-0.84)], respectively. Carriage of rs10484879 minor allele correlated with positive family history of CRC and other cancers (P = 0.002), CRC staging (P = 0.044), CRC treatment (P = 0.038), and with chemo body reaction (P = 0.001). Of the 7 IL-17A variants, 4 were in linkage disequilibrium, hence allowing for construction of 4-locus haplotypes. Varied linkage disequilibrium (LD) was noted between the even tested IL-17A variants, and further analysis was limited to only 4-locus (rs3819024-rs2275913- rs10484879-rs7747909). Haploview analysis identified the 4-locus IL-17A haplotypes AGTG (P < 0.011), and GATG (P = 0.036) to be positively associated with CRC, after controlling key covariates.

CONCLUSION

IL-17A rs10484879 SNP, and IL-17A haplotypes AGGTG and GAGTG constitute independent factors of CRC susceptibility. We propose that IL-17A may be a target for future CRC immunotherapy.

Role of IL-23 signaling in the progression of premalignant oral lesions to cancer

Mice bearing carcinogen-induced premalignant oral lesions were previously shown to have a pro-inflammatory phenotype, which is replaced with an immune inhibitory phenotype as lesions progress to cancer. Since Th17 cells are prominent at the premalignant lesion state and their levels are supported by IL-23, studies used mice that were IL-23 receptor deficient (IL-23R KO) to determine the requirement for IL-23 signaling in the immunological and clinical status of mice with premalignant oral lesions. The results showed a dependence on IL-23 signaling for the pro-inflammatory state of mice with oral lesions as levels of IL-2, IFN-γ, IL-6, IL-17 and TNF-α were elevated in wildtype mice with premalignant oral lesions, but not in IL-23R KO mice. In contrast, as lesions progressed to cancer, the pro-inflammatory phenotype subsided and was replaced with the inhibitory mediator IL-10 and with Treg cells in wildtype mice, although not in IL-23R KO mice. Clinically, early progression of premalignant oral lesions to cancer was enhanced in IL-23R KO mice compared to progression in wildtype mice. These results show the importance of IL-23 signaling in both the pro-inflammatory phenotype characteristic of premalignant oral lesions and the inhibitory phenotype as lesions progress to cancer.

Effects of Th17 cells and IL-17 in the progression of cervical carcinogenesis with high-risk human papillomavirus infection

The existence of Th17 cells and IL‐17 was recently shown in several types of infectious diseases, but their distribution and functions in cervical lesions with high‐risk human papillomavirus (HPV) infection have not been fully elucidated. In this study, the frequency of Th17 cells in peripheral blood samples obtained from 28 cervical squamous cell carcinoma patients, 26 CIN1 patients, 30 CIN2 patients, 29 CIN3 patients, 25 high‐risk HPV‐infected women with normal cervical cytology, and 30 healthy controls was determined by flow cytometry. Besides, the levels of IL‐17 in peripheral blood samples as well as in supernatant of cervical tissue homogenate were assessed by enzyme‐linked immunosorbent assay (ELISA) simultaneously. We found that during the disease progression of cervical lesions, the proportion of Th17 cells in the total CD4⁺ cells showed a gradually increased tendency compared with the controls (P < 0.05). Moreover, levels of IL‐17 in serum and supernatant of cervical tissue homogenate showed the same tendency as the proportion of Th17 cells (P < 0.05). When compared in pairs, the levels of IL‐17 in supernatant differed significantly among the study groups and the control group (P < 0.05), but no significant difference was observed in serum (P > 0.05). In conclusions, the results indicate that Th17 cells and IL‐17 may play a role of immune enhancement in the infection of high‐risk HPV especially in the cervical microenvironment, which contribute to the disease progression of its associated cervical lesions.

Interleukin-6/STAT3 signaling as a promising target to improve the efficacy of cancer immunotherapy

Overcoming the immunosuppressive state in tumor microenvironments is a critical issue for improving the efficacy of cancer immunotherapy. Interleukin (IL)‐6, a pleiotropic cytokine, is highly produced in the tumor‐bearing host. Previous studies have indicated that IL‐6 suppresses the antigen presentation ability of dendritic cells (DC) through activation of signal transducer and activator of transcription 3 (STAT3). Thus, we focused on the precise effect of the IL‐6/STAT3 signaling cascade on human DC and the subsequent induction of antitumor T cell immune responses. Tumor‐infiltrating CD11b⁺CD11c⁺ cells isolated from colorectal cancer tissues showed strong induction of the IL‐6 gene, downregulated surface expression of human leukocyte antigen (HLA)‐DR, and an attenuated T cell‐stimulating ability compared with those from peripheral blood mononuclear cells, suggesting that the tumor microenvironment suppresses antitumor effector cells. In vitro experiments revealed that IL‐6‐mediated STAT3 activation reduced surface expression of HLA‐DR on CD14⁺ monocyte‐derived DC. Moreover, we confirmed that cyclooxygenase 2, lysosome protease and arginase activities were involved in the IL‐6‐mediated downregulation of the surface expression levels of HLA class II on human DC. These findings suggest that IL‐6‐mediated STAT3 activation in the tumor microenvironment inhibits functional maturation of DC to activate effector T cells, blocking introduction of antitumor immunity in cancers. Therefore, we propose in this review that blockade of the IL‐6/STAT3 signaling pathway and target molecules in DC may be a promising strategy to improve the efficacy of immunotherapies for cancer patients.

[Th1/Th2 and Treg/Th17 cell balance in peripheral blood of patients with ovarian cancer]

OBJECTIVE

To investigate the changes in the percentages and balance of CD4⁺T cell subsets including T helper cells (Thl, Th2, and Thl7) and T regulatory cells (Treg) in patients with ovarian cancer.

METHODS

Peripheral blood samples were collected from 30 patients with ovarian cancer and 20 healthy subjects for analysis of the percentages of Thl, Th2, Thl7 and Treg using flow cytometry.

RESULTS

Compared with the control subjects, the patients with ovarian cancer showed significantly increased percentages of Th2, Thl7 and Treg (P<0.05) but significantly decreased percentage of Th1 in the peripheral blood of patients with ovarian cancer (P<0.05). The changes in CD4⁺ T cell subsets were significantly correlated with the clinical stage of the tumor (P<0.05) but not with the histological type or cell differentiation (P>0.05). The Th1/Th2 ratio was significantly decreased in ovarian cancer patients (P<0.05) with obvious Th2 polarization compared with control group. The Treg/Th17 ratio was significantly increased in ovarian cancer patients (P<0.05).

CONCLUSION

Patients with in ovarian cancer have abnormal expressions of CD4⁺T cell subsets in the peripheral blood with Th1/Th2 and Treg/Th17 imbalance, and these findings provide evidence for clinical immunotherapy of ovarian cancer.

Circulating regulatory T cell subsets predict overall survival of patients with unresectable pancreatic cancer

Most patients with pancreatic ductal adenocarcinoma (PDAC) have unresectable cancers with a dismal prognosis, in which cohort chemotherapy is the primary treatment. T cell immune adaption is critical for tumor immune escape and prognosis of this disease. The present study aimed to determine the correlation between peripheral T cell subset distribution in patients with unresectable PDAC and their response to chemotherapy. Two hundred and twelve patients with unresectable PDAC were included whose blood samples were collected for analysis of T cell subsets, including CD3+, CD4+, CD8+, CD8+CD28+ and CD4+CD25+CD127 T cells by flow cytometry before and after gemcitabine-based chemotherapy. Enzyme-linked immunosorbent assay was used to detect the expression levels of tumor growth factor (TGF)-β1, interleukin (IL)-6 and IL-17A in the patients before and after chemotherapy. Univariate and multivariate analyses found that an initial CD4/CD8 ratio or T regulatory (Treg) cell level before any treatment was associated with the prognosis of unresectable PDAC. After two cycles of chemotherapy, there was no significant change in percentages of T cell subsets, except elevation to a higher level of CD3+ T cells. Decreased Tregs or CD4/CD8 ratio after two cycles of chemotherapy predicts a longer overall survival (OS). Levels of Tregs in stable disease (SD) and partial remission (PR) cases significantly decreased after chemotherapy, but increased in progressive disease (PD) patients. There was no correlation between Tregs and the expression level of either TGF-β1 or IL-6. IL-17A expression was elevated in Treg-decreased patients, whereas IL-17A was reduced in Treg-increased patients after chemotherapy. The circulating signature of T cell subsets can predict OS and chemotherapeutic response in patients with unresectable PDAC, and may be attributable to the plasticity of T cell subsets.

Loss of Tff1 Promotes Pro-Inflammatory Phenotype with Increase in the Levels of RORγt+ T Lymphocytes and Il-17 in Mouse Gastric Neoplasia

Background: TFF1 deficiency induces a mucosal pro-inflammatory phenotype that contributes to gastric tumorigenesis in mouse and human. Methods: We utilized the Tff1-KO mouse model to assess the impact of TFF1 loss on immune cells infiltration in the stomach. We used single cell suspension, flow cytometry, immunohistochemistry, and quantitative PCR (qPCR) assays. Results: The Tff1-KO gastric mucosa demonstrated high chronic inflammatory scores (score: 3-4) at age 2 months, which exacerbated at age 8 months (score: 4-6). We next used single-cell suspensions for flow cytometry analysis of total leukocytes (CD45+ cells), total T lymphocytes (CD45+CD3+cells), T cell subsets (CD4+, CD8+, and CD3+CD4-CD8-cells), and monocytes/macrophages (CD45+F4/80+cells). The results demonstrated an age-dependent (2 → 8 month age) significant increase of leukocytes (p<0.05), T cells (p<0.05), and monocytes/macrophages (p<0.001) in the gastric mucosa of the Tff1-KO mice, as compared to Tff1-WT. A similar increase was observed in blood samples (p<0.05). Using ionomycin to activate CD4⁺ splenocytes, the results indicated that Tff1-KO CD4⁺ splenocytes secreted higher levels of IL-17A (p<0.05 at 2 and p<0.001 at 8 months) and IL-17F (p<0.05 at 2 and 8 months) than Tff1-WT splenocytes. Conversely, Tff1-KO CD8⁺-cells secreted less IL-17F, but comparable levels of IL-17A. In addition, we detected a significant upregulation of Il-17 mRNA expression in gastric tissues in the Tff1-KO, as compared to Tff1-WT (p<0.001). Conclusions: The results identify TFF1 loss as a major pro-inflammatory step that modulates the tumor microenvironment and immune cell infiltration in the stomach. Furthermore, the data suggest that the increase of IL-17A and IL-17F in Th17 cells, derived from CD4⁺ T cells, reflects the chronic inflammation in gastric mucosa, whereas the absence of change of IL-17A and decrease of IL-17F in CD8⁺Tc17 cells suggest loss of cytotoxic function of CD8⁺Tc17 cells during gastric tumorigenesis of the Tff1-KO mice.

Checkpoint inhibition for colorectal cancer: progress and possibilities

Colorectal cancer (CRC) remains the third most common cause of cancer death in the USA. Despite an increase in the repertoire of treatment options available for CRC, median overall survival has plateaued at approximately 2.5 years. Strategies that engage the patient's native immune system to overcome checkpoint inhibition have proven to be promising in subsets of CRCs, specifically those with mismatch repair deficiency. Further studies are required to determine combinations of standard therapies with immunotherapy drugs and to discover the best biomarkers to predict response. This review provides insight into the progress made in treating patients with advanced CRC with immunotherapeutics and the areas that demand further research to make these drugs more effective in this patient population.

Th17 Cells in Protection from Tumor or Promotion of Tumor Progression

The roles of inflammation and inflammatory cells such as Th17 cells in the development and progression of cancer have been extensively studied. However, the results have been varied, with conflicting conclusions. Most studies have focused on changes in inflammatory phenotypes once cancers have developed and disease is progressing. Far fewer studies have looked at the immune phenotypic changes that occur during progression of premalignant lesions to cancer. The impact of inflammation and, in particular, Th17 cells on tumor biology is summarized in this review, with a focus on the differences in the outcomes of studies. Possible explanations for the contradictory conclusions are also suggested.