Cytotoxic chemotherapy and CD4+ effector T cells: an emerging alliance for durable antitumor effects

A Simultaneous Presentation of Nasopharyngeal Carcinoma and Latent Cervical Tuberculosis: Insights into a Complex Case

Background and Clinical Significance: Tuberculosis infection triggers a chronic inflammatory response that can create a favorable environment for the development of cancer cells. Chronic inflammation can lead to DNA damage, increased cell proliferation, and impaired immune surveillance. Nasopharyngeal carcinoma is an aggressive malignant tumor with a very poor prognosis, despite the current oncology therapy. Case Presentation: The case presents following clinical, imaging, and histopathological aspects, as well as the oncological follow-up of the patient over a period of 8 years. This paper presents the case of a 49-year-old patient diagnosed with cervical lymph node tuberculosis while biopsied for the diagnosis of nasopharyngeal carcinoma with cervical lymph node metastases. Conclusions: The overlap of this malignancy with an infection of mycobacterial etiology complicates the outcome of the disease even more, making treatment and prognosis difficult.

Single-cell transcriptomic profiling reveals immune cell heterogeneity in acute myeloid leukaemia peripheral blood mononuclear cells after chemotherapy

PURPOSE

Acute myeloid leukaemia (AML) is a heterogeneous disease characterised by the rapid clonal expansion of abnormally differentiated myeloid progenitor cells residing in a complex microenvironment. However, the immune cell types, status, and genome profile of the peripheral blood mononuclear cell (PBMC) microenvironment in AML patients after chemotherapy are poorly understood. In order to explore the immune microenvironment of AML patients after chemotherapy, we conducted this study for providing insights into precision medicine and immunotherapy of AML.

METHODS

In this study, we used single-cell RNA sequencing (scRNA-seq) to analyse the PBMC microenvironment from five AML patients treated with different chemotherapy regimens and six healthy donors. We compared the cell compositions in AML patients and healthy donors, and performed gene set enrichment analysis (GSEA), CellPhoneDB, and copy number variation (CNV) analysis.

RESULTS

Using scRNA-seq technology, 91,772 high quality cells of 44,950 PBMCs from AML patients and 46,822 PBMCs from healthy donors were classified as 14 major cell clusters. Our study revealed the sub-cluster diversity of T cells, natural killer (NK) cells, monocytes, dendritic cells (DCs), and haematopoietic stem cell progenitors (HSC-Prog) in AML patients under chemotherapy. NK cells and monocyte-DCs showed significant changes in transcription factor expression and chromosome copy number variation (CNV). We also observed significant heterogeneity in CNV and intercellular interaction networks in HSC-Prog cells.

CONCLUSION

Our results elucidated the PBMC single-cell landscape and provided insights into precision medicine and immunotherapy for treating AML.

The Possible Role of Anti- and Protumor-Infiltrating Lymphocytes in Pathologic Complete Response in Early Breast Cancer Patients Treated with Neoadjuvant Systemic Therapy

The tumor microenvironment, composed of pro- and antitumor immune cells, affects cancer cell behavior. We aimed to evaluate whether tumor-infiltrating lymphocyte (TIL) density and TIL subtypes in core biopsies at the diagnosis of breast cancer patients could predict a pathologic complete response (pCR; ypT0/is ypN0) from neoadjuvant systemic therapy (NST). The TIL subtypes were determined based on the proportions of presumably antitumor (CD8+, CXCL13+) and protumor (PD-1+, FOXP3+) immune cells. A prospective, noninterventional study, including 171 participants undergoing NST, was performed. The median TIL density for the entire cohort was 10% (IQR: 3.5-23.8), and 59 (35%) patients achieved pCR. TIL density was positively associated with pCR (univariately and multivariably). In the multivariable logistic regression model, TIL density was an independent predictor of pCR (p = 0.012, OR 1.27; 95% CI 1.05-1.54) when controlled for age (p = 0.232), Ki-67 (p = 0.001), node-negative status (p = 0.024), and HER2+/triple negative vs. luminal B-like subtype (p < 0.001). In our sample, higher proportions of PD-1+ TILs and FOXP3+ TILs were associated with a higher probability of pCR but the association was not statistically significant and we could not make any conclusions on the direction of associations in the model with all four biomarkers. In the exploratory multivariable analysis, we showed that only higher CD8+ TILs were associated with pCR. In conclusion, TIL density and its subtypes are associated with pCR.

Acute inflammatory reaction during anti-angiogenesis therapy combined with immunotherapy as a possible indicator of the therapeutic effect: Three case reports and literature review

The posterior line treatment of unresectable advanced or metastatic gastrointestinal (GI) tumors has always been a challenging point. In particular, for patients with microsatellite stable (MSS)/mismatch repair proficient (pMMR) 0GI tumors, the difficulty of treatment is exacerbated due to their insensitivity to immune drugs. Accordingly, finding a new comprehensive therapy to improve the treatment effect is urgent. In this study, we report the treatment histories of three patients with MSS/pMMR GI tumors who achieved satisfactory effects by using a comprehensive treatment regimen of apatinib combined with camrelizumab and TAS-102 after the failure of first- or second-line regimens. The specific contents of the treatment plan were as follows: apatinib (500 mg/d) was administered orally for 10 days, followed by camrelizumab (200 mg, ivgtt, day 1, 14 days/cycle) and TAS-102 (20 mg, oral, days 1-21, 28 days/cycle). Apatinib (500 mg/d) was maintained during treatment. Subsequently, we discuss the possible mechanism of this combination and review the relevant literature, and introduce clinical trials on anti-angiogenesis therapy combined with immunotherapy.

Immunotherapy for advanced hepatocellular carcinoma: From clinical trials to real-world data and future advances

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated mortality worldwide. HCC is an inflammation-associated immunogenic cancer that frequently arises in chronically inflamed livers. Advanced HCC is managed with systemic therapies; the tyrosine kinase inhibitor (TKI) sorafenib has been used in 1st-line setting since 2007. Immunotherapies have emerged as promising treatments across solid tumors including HCC for which immune checkpoint inhibitors (ICIs) are licensed in 1st- and 2nd-line treatment setting. The treatment field of advanced HCC is continuously evolving. Several clinical trials are investigating novel ICI candidates as well as new ICI regimens in combination with other therapeutic modalities including systemic agents, such as other ICIs, TKIs, and anti-angiogenics. Novel immunotherapies including adoptive cell transfer, vaccine-based approaches, and virotherapy are also being brought to the fore. Yet, despite advances, several challenges persist. Lack of real-world data on the use of immunotherapy for advanced HCC in patients outside of clinical trials constitutes a main limitation hindering the breadth of application and generalizability of data to this larger and more diverse patient cohort. Consequently, issues encountered in real-world practice include patient ineligibly for immunotherapy because of contraindications, comorbidities, or poor performance status; lack of response, efficacy, and safety data; and cost-effectiveness. Further real-world data from high-quality large prospective cohort studies of immunotherapy in patients with advanced HCC is mandated to aid evidence-based clinical decision-making. This review provides a critical and comprehensive overview of clinical trials and real-world data of immunotherapy for HCC, with a focus on ICIs, as well as novel immunotherapy strategies underway.

Challenges of CAR T-cell Therapy in CLL: Lessons Learned

Development of chimeric antigen receptor T (CART) cell therapy has led to unprecedented success against B cell leukemia and lymphoma and resulted in FDA-approved treatment protocols. Despite the initial clinical response in B cell-related malignancies, high relapse rates suggest that much work is needed to uncover mechanisms of resistance. In chronic lymphocytic leukemia (CLL), the durable activity of CAR T-cells is limited, and CART cell success is lower than in other malignancies. T cells from these patients are vulnerable to a state of dysfunction due to stresses including chronic infection, rapid cell cycle upon antigen recognition, immunosuppressive tumor microenvironment, and cancer-related treatments. T cells are also introduced to additional stresses when cultured ex vivo during the CART manufacturing process. All these factors contribute to the limited regenerative capacity of T cells, which can lead to CART treatment failure. In this short report, we will review the challenges of CAR T-cell therapy in patients with CLL and discuss potential strategies to overcome these challenges.

Impact of Epithelial-Mesenchymal Transition on the Immune Landscape in Breast Cancer

The impact of epithelial-mesenchymal transition (EMT) signature on the immune infiltrate present in the breast cancer tumor microenvironment (TME) is still poorly understood. Since there is mounting interest in the use of immunotherapy for the treatment of subsets of breast cancer patients, it is of major importance to understand the fundamental tumor characteristics which dictate the inter-tumor heterogeneity in immune landscapes. We aimed to assess the impact of EMT-related markers on the nature and magnitude of the inflammatory infiltrate present in breast cancer TME and their association with the clinicopathological parameters. Tissue microarrays were constructed from 144 formalin-fixed paraffin-embedded invasive breast cancer tumor samples. The protein expression patterns of Snail, Twist, ZEB1, N-cadherin, Vimentin, GRHL2, E-cadherin, and EpCAM were examined by immunohistochemistry (IHC). The inflammatory infiltrate in the TME was assessed semi-quantitatively on hematoxylin and eosin (H&E)-stained whole sections and was characterized using IHC. The inflammatory infiltrate was more intense in poorly differentiated carcinomas and triple-negative carcinomas in which the expression of E-cadherin and GRHL2 was reduced, while EpCAM was overexpressed. Most EMT-related markers correlated with plasma cell infiltration of the TME. Taken together, our findings reveal that the EMT signature might impact the immune response in the TME.

Associations among cytokines, EGF and lymphocyte subpopulations in patients diagnosed with advanced lung cancer

Aging is considered the single most significant risk factor for the majority of common malignances including lung cancer. Together immunosenescence, changes occurring with aging in the immune system, and inflammaging, characterizes by a chronic, subclinical accumulation of pro-inflammatory factors, are suggested to stand at the origin of most of the diseases of the elderly, such as cancer. The aim of this study was to determine associations among lymphocyte subpopulations, pro-inflammatory cytokines and epidermal growth factor (EGF) in patients diagnosed with non-small cell lung cancer (NSCLC). Forty-six advanced NSCLC patients were enrolled. Sixteen patients with newly diagnosed and before treatment and 30 patients after first-line platinum-based chemotherapy. Peripheral blood subpopulations were studied by flow cytometry and serum concentrations of soluble factors by ELISA. The frequency of naïve CD4⁺ T cells, naïve B cells and central memory CD8⁺ T cells were significantly lower in NSCLC patients after chemotherapy, while effector memory CD4⁺ T cells and terminally differentiated CD8⁺ T cells were significantly higher. IL-1β and TNFα significantly correlated among them before and after platinum-based chemotherapy. Terminally differentiated T cells expressing CD57⁺ significantly correlated with TNFα and IL-1β. For the first time, associations between EGF serum levels and terminally differentiated CD4⁺ T cells, and memory B cells were detected. This study confirms the association among terminally differentiated lymphocytes and pro-inflammatory cytokines in patients diagnosed with lung cancer, reinforcing the interconnection between terminally differentiated lymphocytes and pro-inflammatory cytokines. Clinical trial registration number: RPCEC00000205, http://registroclinico.sld.cu/.

Identification of an immunogenic DKK1 long peptide for immunotherapy of human multiple myeloma

Dickkopf-1 (DKK1), broadly expressed by tumor cells from human multiple myeloma (MM) and other cancers but absent from most normal tissues, may be an ideal target for immunotherapy. Our previous studies have shown that DKK1 (peptide)-specific cytotoxic T lymphocytes can effectively lyse primary MM cells in vitro. To develop DKK1-based vaccines that can be easily and inexpensively made and used by all patients, we identified a DKK1 long peptide (LP), DKK13-76-LP, that contains 74 amino acids and epitopes that can potentially bind to all major MHC class I and II molecules. Using HLA-A*0201- and HLA-DR*4-transgenic mouse models, we found that DKK1-specific CD4+ and CD8+ T-cell responses, detected by DKK1 short peptide (P20 and P66v)-HLA-A*0201 tetramer staining and cytotoxic assay for CD8+ T cells or by carboxyfluorescein diacetate succinimidyl ester (CSFE) dilution and IFN-g secretion for CD4+ T cells, respectively, can be induced in vivo by immunizing mice with the DKK13-76-LP. In addition, DKK13-76-LP also induced anti-DKK1 humoral immunity in the transgenic mice and the DKK1 antibodies were functional. Finally, DKK13-76-LP stimulated human blood T cells ex vivo to generate DKK1-specific CD4+ and CD8+ T-cell responses from 8 out of 10 MM patients with different MHC backgrounds. The generated DKK1-specific CD8+ cells efficiently lysed autologous MM cells from these patients. Thus, these results confirm the immunogenicity of the DKK13-76-LP in eliciting DKK1-specific CD4+ and CD8+ T-cell responses in vitro and in vivo, and suggest that the DKK13-76-LP can be used for immunotherapy of MM and other cancers.

Spatial Distribution and Prognostic Implications of Tumor-Infiltrating FoxP3- CD4+ T Cells in Biliary Tract Cancer

PURPOSE

The clinical implications of tumor-infiltrating T cell subsets and their spatial distribution in biliary tract cancer (BTC) patients treated with gemcitabine plus cisplatin were investigated.

MATERIALS AND METHODS

A total of 52 BTC patients treated with palliative gemcitabine plus cisplatin were included. Multiplexed immunohistochemistry was performed on tumor tissues, and immune infiltrates were separately analyzed for the stroma, tumor margin, and tumor core.

RESULTS

The density of CD8+ T cells, FoxP3- CD4+ helper T cells, and FoxP3+ CD4+ regulatory T cells was significantly higher in the tumor margin than in the stroma and tumor core. The density of LAG3- or TIM3-expressing CD8+ T cell and FoxP3- CD4+ helper T cell infiltrates was also higher in the tumor margin. In extrahepatic cholangiocarcinoma, there was a higher density of T cell subsets in the tumor core and regulatory T cells in all regions. A high density of FoxP3- CD4+ helper T cells in the tumor margin showed a trend toward better progression-free survival (PFS) (p=0.092) and significantly better overall survival (OS) (p=0.012). In multivariate analyses, a high density of FoxP3- CD4+ helper T cells in the tumor margin was independently associated with favorable PFS and OS.

CONCLUSION

The tumor margin is the major site for the active infiltration of T cell subsets with higher levels of LAG3 and TIM3 expression in BTC. The density of tumor margin-infiltrating FoxP3- CD4+ helper T cells may be associated with clinical outcomes in BTC patients treated with gemcitabine plus cisplatin.

Persistent STAT5 activation reprograms the epigenetic landscape in CD4+ T cells to drive polyfunctionality and antitumor immunity

The presence of polyfunctional CD4+ T cells is often associated with favorable antitumor immunity. We report here that persistent activation of signal transducer and activator of transcription 5 (STAT5) in tumor-specific CD4+ T cells drives the development of polyfunctional T cells. We showed that ectopic expression of a constitutively active form of murine STAT5A (CASTAT5) enabled tumor-specific CD4+ T cells to undergo robust expansion, infiltrate tumors vigorously, and elicit antitumor CD8+ T cell responses in a CD4+ T cell adoptive transfer model system. Integrated epigenomic and transcriptomic analysis revealed that CASTAT5 induced genome-wide chromatin remodeling in CD4+ T cells and established a distinct epigenetic and transcriptional landscape. Single-cell RNA sequencing analysis further identified a subset of CASTAT5-transduced CD4+ T cells with a molecular signature indicative of progenitor polyfunctional T cells. The therapeutic significance of CASTAT5 came from our finding that adoptive transfer of T cells engineered to coexpress CD19-targeting chimeric antigen receptor (CAR) and CASTAT5 gave rise to polyfunctional CD4+ CAR T cells in a mouse B cell lymphoma model. The optimal therapeutic outcome was obtained when both CD4+ and CD8+ CAR T cells were transduced with CASTAT5, indicating that CASTAT5 facilitates productive CD4 help to CD8+ T cells. Furthermore, we provide evidence that CASTAT5 is functional in primary human CD4+ T cells, underscoring its potential clinical relevance. Our results implicate STAT5 as a valid candidate for T cell engineering to generate polyfunctional, exhaustion-resistant, and tumor-tropic antitumor CD4+ T cells to potentiate adoptive T cell therapy for cancer.

Circulating activated lymphocyte subsets as potential blood biomarkers of cancer progression

The objective of this study was to predict the value of lymphocyte subsets in cancer progression. Peripheral blood was obtained from 327 untreated patients with cancer and 158 healthy volunteers. Levels of lymphocyte subsets were determined by flow cytometry. There were decreased levels of natural killer (NK) cells, CD8⁺ T cells, and naïve CD4⁺/CD4⁺ T cells in untreated patients with cancer compared to those in healthy controls. Inversely, there were elevated levels of the following T‐cell percentages in cancer patients compared to those in healthy controls: memory CD4⁺/CD4⁺, CD8⁺ T cells, HLA‐DR/CD8⁺, CD8⁺ CD38⁺/CD8⁺, and CD4⁺/CD8⁺. In addition, there are a decreasing trend in terms of CD4⁺ T‐cell counts and an increase CD8⁺ HLA‐DR/CD8⁺ T‐cell and CD8⁺ CD38⁺/CD8⁺ T‐cell percentages in the advanced stage. An increasing trend with advanced tumor stage and the percentages of CD8⁺ HLA‐DR/CD8⁺ T cells and CD8⁺ CD38⁺/CD8⁺ T cells was shown in this study. There are a negative correlation for CD4⁺ T‐cell counts and positive correlation for percentages of CD8⁺ HLA‐DR/CD8⁺ T cell and CD8⁺ CD38⁺/CD8⁺ T cells with the lymph node metastasis. In the presence of distant metastatic spread, we observed higher NK‐cell counts, CD8⁺ HLA‐DR/CD8⁺ T‐cell percentages, CD8⁺ CD38⁺/CD8⁺ T‐cell percentages, as well as lower CD4⁺ T‐cell counts than those in the absence of distant metastases spread. Abnormal levels of NK cell, CD8⁺ T cells, memory CD4⁺/CD4⁺, naïve CD4⁺/ CD4⁺, CD8⁺ HLA‐DR/CD8⁺, CD8⁺ CD38⁺/CD8⁺, and CD4⁺/CD8⁺ can be a potential blood biomarkers of cancer development. CD4+ T‐cell counts and percentages of CD8⁺ HLA‐DR/ CD8⁺ and CD8⁺ CD38⁺/ CD8⁺ can predict the cancer progression.

Emerging strategies in cancer therapy combining chemotherapy with immunotherapy

Cancer immunotherapy holds great potential to battle cancer by exerting a durable immunity effect. However, this process might be limited by various constraints existing in the tumor microenvironment (TME), such as the lack of available neoantigen, insufficient T cells from the naive repertoire, or immunosuppressive networks in which immunogenic tissue is protected from immune attacks. Certain chemotherapeutic drugs could elicit immune-potentiating effects by either inducing immunogenicity or relieving tumor-induced immunosuppression. Some also leave tumors directly susceptible to cytotoxic T cell attacks. Mounting evidence accumulated from preclinical and clinical studies suggests that these two treatment modalities might be mutually reinforcing as an effective "chemo-immunotherapy" strategy. Herein, we reviewed the latest advances in cancer immunotherapy and related mechanisms involved in chemotherapeutic-mediated immune activation. The emerging combination strategies and synergistic effects in response to chemo-immunotherapy are highlighted. We also discuss the challenges and critical considerations in its future development.

Phase II Study of the PD-1 Inhibitor Pembrolizumab for the Treatment of Relapsed or Refractory Mature T-cell Lymphoma

BACKGROUND

Programmed cell death-1 (PD-1) and programmed death-ligand 1 (PD-L1) are frequently expressed in T-cell lymphomas. This provides a rationale for exploration of immune checkpoint inhibitors in the management of T-cell lymphomas.

PATIENTS AND METHODS

In this phase II single-arm multicenter trial, patients with relapsed or refractory systemic T-cell lymphoma were treated with 200 mg pembrolizumab intravenously every 21 days. The primary endpoint was progression-free survival (PFS). The secondary endpoints were response rate, overall survival, response duration, and safety. We assessed PD-L1, p-AKT expression, and peripheral blood immune cells as potential predictive biomarkers.

RESULTS

Of 18 enrolled patients, 13 were evaluable for the primary endpoint. The trial was halted early after a preplanned interim futility analysis. The overall response rate was 33% (95% confidence interval [CI], 9%-55%); 4 patients achieved a complete response (27%; 95% CI, 5%-49%). The median PFS was 3.2 months (95% CI, 1.2-3.7 months), and the median overall survival was 10.6 months (95% CI, 3.2-100 months). The median duration of response was 2.9 months (95% CI, 0-10.1 months). Two of the 4 complete responders remain in remission > 15 months. Rash was the most common adverse event (17%; n = 3). The most common ≥ grade 3 treatment-emergent adverse events were rash and pneumonitis (11%; n = 2 each). Neither PD-L1 nor p-AKT expression were associated with outcomes. However, a higher relative frequency of CD4⁺ T lymphocytes pre-treatment was associated with improved PFS (hazard ratio, 0.15; 95% CI, 0.03-0.74).

CONCLUSION

Pembrolizumab demonstrated modest single-agent activity in relapsed or refractory T-cell lymphoma.

Chimeric antigen receptor-modified T cell therapy in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL), a common type of B cell chronic lymphoproliferative disorder in adults, has witnessed enormous development in its treatment in recent years. New drugs such as ibrutinib, idelalisib, and venetoclax have achieved great success in treating relapsed and refractory (R/R) CLL. In addition, with the development of immunotherapy, chimeric antigen receptor-engineered T cells (CAR-T) therapy, a novel adoptive immune treatment, has also become more and more important in treating R/R CLL. It combines the advantages of T cells and B cells via ex vivo gene transfer technology and is able to bind targets recognized by specific antibodies without antigen presentation, thus breaking the restriction of major histocompatibility complex. So far, there have been lots of studies exploring the application of CAR-T therapy in CLL. In this review, we describe the structure of chimeric antigen receptor, the preclinical, and clinical results of CAR-T therapy against CLL, along with its adverse events and advances in efficacy.

Overexpression of kinesin family member 20A is associated with unfavorable clinical outcome and tumor progression in epithelial ovarian cancer

Background

KIF20A plays an indispensable role in cytokinesis regulation, which is important for tumor proliferation and growth. Recently, the oncogenic role of KIF20A has been well documented in several cancers. However, its clinical role in epithelial ovarian cancer (EOC) remains not reported yet. We investigated its expression and its role in promoting invasion and chemoresistance in EOC cells.

Patients and methods

KIF20A transcription and translation levels were investigated in normal ovarian epithelial cell, ovarian cancer cells, and 10 pairs of fresh EOC tissues and adjacent normal ovarian tissues by real-time quantitative polymerase chain reaction and Western blots. Moreover, KIF20A protein level was also examined by immunohistochemistry in 150 EOC tissues. The correlation between KIF20A expression and clinical variables was analyzed by statistical methods. We also used wound healing assay, transwell assay MTT, and Annexin V/PI to explore KIF20A functions.

Results

KIF20A expression was obviously elevated at both mRNA and protein levels in EOC cell lines and clinical cancer tissues compared with normal ovarian epithelial cell and adjacent normal ovarian tissues. KIF20A protein expression was highly correlated with International Federation of Gynecology and Obstetrics stage (P=0.008), lymph node metastasis (P=0.002), intraperitoneal metastasis (P<0.001), vital status at last follow-up (P<0.001), intraperitoneal recurrence (P=0.030), tumor recurrence (P=0.005), drug resistance (P=0.013), and ascites with tumor cells (P<0.001). KIF20A overexpression was closely related to poorer overall survival and disease progression-free survival. Furthermore, Cox regression analysis revealed that KIF20A can act as an independent hazard indicator for predicting clinical outcomes in EOC patients. Interestingly, KIF20A overexpression promoted invasion and metastasis of EOC cells and also confers resistance to cisplatin.

Conclusion

Our findings indicated that KIF20A overexpression predicts unfavorable clinical outcome, revealing that KIF20A holds a promising potential to serve as a useful prognostic biomarker for EOC patients.

The distribution and function of human memory T cell subsets in lung cancer

The distribution and function of T lymphocytes in human lung cancer remain limited. In this study, we investigated the properties of human T cell subsets in the blood of non-small cell lung cancer (NSCLC) patients. We found a relatively normal level of CD4+ subsets in the blood of NSCLC patients, but CD8+ effector T cells increased and CD8+ effector memory cells declined compared to the healthy donors. To further analyze their properties, we stimulated the peripheral blood mononuclear cells (PBMCs) of NSCLC patients by mitogens to examine cytokine production. Our data suggest that both CD4+ and CD8+ naïve cells in NSCLC patients significantly reduced IFN-γ and TNF-α production. Additionally, fewer CD8+ effector cells produced IFN-γ and TNF-α in NSCLC patients than in healthy subjects. Moreover, similar results were observed for CD4+ or CD8+ memory cells in NSCLC patients for the production of IFN-γ, TNF-α, and IL-17. Therefore, our results strongly suggest that the function of CD4+ and CD8+ T lymphocytes in NSCLC patients is compromised or dysregulated. The development of vaccines and antitumor immunotherapy may be essential for the treatment of lung cancer patients.

Definitive activation of endogenous antitumor immunity by repetitive cycles of cyclophosphamide with interspersed Toll-like receptor agonists

Many cancers both evoke and subvert endogenous anti-tumor immunity. However, immunosuppression can be therapeutically reversed in subsets of cancer patients by treatments such as checkpoint inhibitors or Toll-like receptor agonists (TLRa). Moreover, chemotherapy can leukodeplete immunosuppressive host elements, including myeloid-derived suppressor cells (MDSCs) and regulatory T-cells (Tregs). We hypothesized that chemotherapy-induced leukodepletion could be immunopotentiated by co-administering TLRa to emulate a life-threatening infection. Combining CpG (ODN 1826) or CpG+poly(I:C) with cyclophosphamide (CY) resulted in uniquely well-tolerated therapeutic synergy, permanently eradicating advanced mouse tumors including 4T1 (breast), Panc02 (pancreas) and CT26 (colorectal). Definitive treatment required endogenous CD8+ and CD4+ IFNγ-producing T-cells. Tumor-specific IFNγ-producing T-cells persisted during CY-induced leukopenia, whereas Tregs were progressively eliminated, especially intratumorally. Spleen-associated MDSCs were cyclically depleted by CY+TLRa treatment, with residual monocytic MDSCs requiring only continued exposure to CpG or CpG+IFNγ to effectively attack malignant cells while sparing non-transformed cells. Such tumor destruction occurred despite upregulated tumor expression of Programmed Death Ligand-1, but could be blocked by clodronate-loaded liposomes to deplete phagocytic cells or by nitric oxide synthase inhibitors. CY+TLRa also induced tumoricidal myeloid cells in naive mice, indicating that CY+TLRa's immunomodulatory impacts occurred in the complete absence of tumor-bearing, and that tumor-induced MDSCs were not an essential source of tumoricidal myeloid precursors. Repetitive CY+TLRa can therefore modulate endogenous immunity to eradicate advanced tumors without vaccinations or adoptive T-cell therapy. Human blood monocytes could be rendered similarly tumoricidal during in vitro activation with TLRa+IFNγ, underscoring the potential therapeutic relevance of these mouse tumor studies to cancer patients.

Immunostimulatory Effects of Melphalan and Usefulness in Adoptive Cell Therapy with Antitumor CD4+ T Cells

The alkylating agent melphalan is used in the treatment of hematological malignancies, especially multiple myeloma. In the past, the usefulness of melphalan has been solely attributed to its cytotoxicity on fastgrowing cancerous cells. Although the immunomodulatory effects of melphalan were suggested many years ago, only recently has this aspect of melphalan's activity begun to be elucidated at the molecular level. Emerging evidence indicates that melphalan can foster an immunogenic microenvironment by inducing immunogenic cell death (ICD) as characterized by membrane translocation of endoplasmic reticulum protein calreticulin (CRT) and by release of chromatin-binding protein high-mobility group box 1 (HMGB1). In addition, the lympho-depletive effect of melphalan can induce the release of pro-inflammatory cytokines and growth factors, deplete regulatory T cells, and create space to facilitate the expansion of infused tumor-reactive T cells. These features suggest that melphalan can be used as a preparative chemotherapy for adoptive T-cell therapy. This notion is supported by our recent work demonstrating that the combination of melphalan and adoptive transfer of tumor-reactive CD4+ T cells can mediate potent antitumor effects in animal models. This review summarizes the recent advances in understanding and utilizing the immunomodulatory effects of melphalan.

The Immune-microenvironment Confers Chemoresistance of Colorectal Cancer through Macrophage-Derived IL6

Purpose: Tumor-associated macrophages (TAMs) are frequently associated with poor prognosis in human cancers. However, the effects of TAMs in colorectal cancer are contradictory. We therefore investigated the functions, mechanisms, and clinical significance of TAMs in colorectal cancer.Experimental Design: We measured the macrophage infiltration (CD68), P-gp, and Bcl2 expression in colorectal cancer tissues using IHC staining. Coculture of TAMs and colorectal cancer cells both in vitro and in vivo models was used to evaluate the effects of TAMs on colorectal cancer chemoresistance. Cytokine antibody arrays, ELISA, neutralizing antibody, and luciferase reporter assay were performed to uncover the underlying mechanism.Results: TAM infiltration was associated with chemoresistance in patients with colorectal cancer. Colorectal cancer-conditioned macrophages increased colorectal cancer chemoresistance and reduced drug-induced apoptosis by secreting IL6, which could be blocked by a neutralizing anti-IL6 antibody. Macrophage-derived IL6 activated the IL6R/STAT3 pathway in colorectal cancer cells, and activated STAT3 transcriptionally inhibited the tumor suppressor miR-204-5p. Rescue experiment confirmed that miR-204-5p is a functional target mediating the TAM-induced colorectal cancer chemoresistance. miR-155-5p, a key miRNA regulating C/EBPβ, was frequently downregulated in TAMs, resulting in increased C/EBPβ expression. C/EBPβ transcriptionally activated IL6 in TAMs, and TAM-secreted IL6 then induced chemoresistance by activating the IL6R/STAT3/miR-204-5p pathway in colorectal cancer cells.Conclusions: Our data indicate that the maladjusted miR-155-5p/C/EBPβ/IL6 signaling in TAMs could induce chemoresistance in colorectal cancer cells by regulating the IL6R/STAT3/miR-204-5p axis, revealing a new cross-talk between immune cells and tumor cells in colorectal cancer microenvironment. Clin Cancer Res; 23(23); 7375-87. ©2017 AACR.

Prognostic Significance of Tumor-Infiltrating Lymphocytes in Patients With Pancreatic Ductal Adenocarcinoma Treated With Neoadjuvant Chemotherapy

OBJECTIVES

The aim of this study was to examine tumor-infiltrating lymphocytes (TILs) and their prognostic value in patients with pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant therapy.

METHODS

Intratumoral CD4, CD8, and FOXP3 lymphocytes were examined by immunohistochemistry using a computer-assisted quantitative analysis in 136 PDAC patients who received neoadjuvant therapy and pancreaticoduodenectomy. The results were correlated with clinicopathological parameters and survival.

RESULTS

High CD4 TILs in treated PDAC were associated with high CD8 TILs (P = 0.003), differentiation (P = 0.04), and a lower frequency of recurrence (P = 0.02). Patients with high CD4 TILs had longer disease-free survival and overall survival (OS) than did patients with low CD4 TILs (P < 0.01). The median OS of patients with a high CD8/FOXP3 lymphocyte ratio (39.5 [standard deviation, 6.1] months) was longer than that of patients with a low CD8/FOXP3 lymphocyte ratio (28.3 [standard deviation, 2.3] months; P = 0.01). In multivariate analysis, high CD4 TILs were an independent prognostic factor for disease-free survival (hazard ratio, 0.49; 95% confidence interval, 0.30-0.81; P = 0.005) and OS (hazard ratio, 0.54; 95% confidence interval, 0.33-0.89; P = 0.02).

CONCLUSIONS

High level of CD4 lymphocytes is associated with tumor differentiation and lower recurrence and is an independent prognostic factor for survival in PDAC patients treated with neoadjuvant therapy.

Overexpression of Kinesin Family Member 20A Correlates with Disease Progression and Poor Prognosis in Human Nasopharyngeal Cancer: A Retrospective Analysis of 105 Patients

BACKGROUND

Numerous studies have shown Kinesin family member 20A (KIF20A) may play a critical role in the development and progression of cancer. However, the clinical value of KIF20A in nasopharyngeal carcinoma (NPC) is unknown. Here, we investigated the expression pattern of KIF20A in NPC and its correlation with clinicopathological features of patients.

METHODS

Real-time PCR and Western blotting were used to quantify KIF20A expression in NPC cell lines and clinical specimens compared with normal controls. KIF20A protein expression was also examined in archived paraffin embedded tumor samples from 105 patients with pathologically confirmed NPC by immunohistochemistry (IHC). Statistical analyses were applied to assess the associations between KIF20A expression and the clinicopathological features and survival outcomes. Effects on migration and invasion were assessed by wound healing and transwell invasion assays after KIF20A silencing.

RESULTS

KIF20A was significantly overexpressed at both the mRNA and protein levels in NPC cell lines and human tumor tissues. 45/105 (42.9%) of NPC specimens expressed high levels of KIF20A among the KIF20A detectable cases. Statistical analysis revealed that high KIF20A expression was significantly associated with gender (P = 0.046), clinical stage (P<0.001), T category (P = 0.022), N category (P<0.001), distant metastasis (P = 0.001) and vital status (P = 0.001). Moreover, Higher KIF20A expression patients had shorter overall survival (OS) and progression-free survival (PFS) (P = 0.001 and P = 0.001; log-rank test). In multivariate analysis, KIF20A was an independent prognostic factor for OS and PFS in the entire cohort (P = 0.033, P = 0.008). Knock down of KIF20A expression significantly suppressed NPC cell's migration and invasion.

CONCLUSIONS

KIF20A is overexpressed and may serve as an independent prognostic biomarker in NPC. Targeting KIF20A reduces migration and invasion of NPC cells.

Breast Cancer Immunology and Immunotherapy: Current Status and Future Perspectives

Cancer immunology has gained renewed interest in the past few years due to emerging findings on mechanisms involved in tumoral immune evasion. Indisputably, immune edition is currently considered a critical hallmark of cancer. Basic research has revealed new targets which can be modulated in the clinical setting with new compounds and strategies. As recent evidence confirms, breast cancer (BC) is a complex and heterogeneous disease in which host immune responses play a substantial role. T-infiltrating lymphocytes measurement is suggested as a powerful new tool necessary to predict early BC evolution, especially in HER2-positive and triple negative subtypes. However, T-infiltrating lymphocytes, genomic platforms, and many other biomarkers in tissue and peripheral blood (e.g., regulatory T cells and myeloid-derived suppressor cells) are not the only factors being evaluated regarding their potential role as prognostic and/or predictive factors. Many ongoing clinical trials are exploring the activity of immune checkpoint modulators in BC treatment, both in the advanced and neoadjuvant setting. Although this field is expanding with exciting new discoveries and promising clinical results-and creating great expectations-there remain many uncertainties yet to be addressed satisfactorily before this long awaited therapeutic promise can come to fruition.

IL-7 signaling imparts polyfunctionality and stemness potential to CD4(+) T cells

The functional status of CD4(+) T cells is a critical determinant of antitumor immunity. Polyfunctional CD4(+) T cells possess the ability to concomitantly produce multiple Th1-type cytokines, exhibiting a functional attribute desirable for cancer immunotherapy. However, the mechanisms by which these cells are induced are neither defined nor it is clear if these cells can be used therapeutically to treat cancer. Here, we report that CD4(+) T cells exposed to exogenous IL-7 during antigenic stimulation can acquire a polyfunctional phenotype, characterized by their ability to simultaneously express IFNγ, IL-2, TNFα and granzyme B. This IL-7-driven polyfunctional phenotype was associated with increased histone acetylation in the promoters of the effector genes, indicative of increased chromatin accessibility. Moreover, forced expression of a constitutively active (CA) form of STAT5 recapitulated IL-7 in inducing CD4(+) T-cell polyfunctionality. Conversely, the expression of a dominant negative (DN) form of STAT5 abolished the ability of IL-7 to induce polyfunctional CD4(+) T cells. These in-vitro-generated polyfunctional CD4(+) T cells can traffic to tumor and expand intratumorally in response to immunization. Importantly, adoptive transfer of polyfunctional CD4(+) T cells following lymphodepletive chemotherapy was able to eradicate large established tumors. This beneficial outcome was associated with the occurrence of antigen epitope spreading, activation of the endogenous CD8(+) T cells and persistence of donor CD4(+) T cells exhibiting memory stem cell attributes. These findings indicate that IL-7 signaling can impart polyfunctionality and stemness potential to CD4(+) T cells, revealing a previously unknown property of IL-7 that can be exploited in adoptive T-cell immunotherapy.

Chemopreventive and immunomodulatory effects of Murraya koenigii aqueous extract on 4T1 breast cancer cell-challenged mice

BACKGROUND

The progression of breast cancer is increasing at an alarming rate, particularly in western countries. Meanwhile, the lower incidence in Asian countries could be attributed to the heavy incorporation of green leaves vegetables or spices in their diets. Murraya koenigii (MK) or often times known as curry leaves are common spice used mostly in tropical countries. Anti-inflammatory and chemopreventive effects of MK aqueous extract on 4T1 breast cancer cell-challenged mice were evaluated.

METHODS

Herein, cytotoxic activity of MK was first tested on 4T1 cells in vitroby MTT assay. Then, in vivo chemopreventive study was conducted where mice were fed with extracts prior to and after inducing the tumor (inoculation). Tumor size was monitored post-4T1 inoculation. At the end of experiment, histopathology of tumor sections, T cell immunophenotyping, tumor nitric oxide level, serum cytokine level and qPCR analysis on expression of iNOS, iCAM, NF-kB and c-MYC were performed.

RESULTS

MK reduced the tumors' size and lung metastasis aside from inhibited the viability of 4T1 cells in vitro. Furthermore, it decreased the level of nitric oxide and inflammation-related cytokines and genes, including iNOS, iCAM, NF-kB and c-MYC.

CONCLUSION

The results propose that, MK managed to inhibit the progression of tumor via immunostimulatory effect and inflammatory reaction within the tumor samples. This suggests that MKconsumption could be a savior in the search of new chemopreventive agents.

Enhancement of anti-tumor effect of particulate vaccine delivery system by 'bacteriomimetic' CpG functionalization of poly-lactic-co-glycolic acid nanoparticles

AIM

Low immunogenicity remains a major obstacle in realizing the full potential of cancer vaccines. In this study, we evaluated CpG-coated tumor antigen (Tag)-encapsulating 'bacteriomimetic' nanoparticles (CpG-nanoparticle [NP]-Tag NPs) as an approach to enhance anti-tumor immunity.

MATERIALS & METHODS

CpG-NP-Tag NPs were synthesized, characterized for their physicochemical properties and tested in vivo.

RESULTS

We found CpG predosing followed by intraperitoneal (IP) immunization with CpG-NP-Tag NPs significantly attenuated tumor growth in female BALB/c mice compared with respective controls. Histopathological and Immunofluorescence data revealed CpG-NP-Tag tumors had lower proliferation, higher apoptotic activity, greater CD4(+) and CD8(+) T cell infiltration as well as higher IFN-γ levels as compared with control groups.

CONCLUSION

Our findings suggest CpG-NP-Tag NPs can enhance anti-tumor effect of nanoparticulate tumor vaccination system.

Metronomic cyclophosphamide eradicates large implanted GL261 gliomas by activating antitumor Cd8+ T-cell responses and immune memory

Cancer chemotherapy using cytotoxic drugs can induce immunogenic tumor cell death; however, dosing regimens and schedules that enable single-agent chemotherapy to induce adaptive immune-dependent ablation of large, established tumors with activation of long-term immune memory have not been identified. Here, we investigate this issue in a syngeneic, implanted GL261 glioma model in immune-competent mice given cyclophosphamide on a 6-day repeating metronomic schedule. Two cycles of metronomic cyclophosphamide treatment induced sustained upregulation of tumor-associated CD8⁺ cytotoxic T lymphocyte (CTL) cells, natural killer (NK) cells, macrophages, and other immune cells. Expression of CTL- and NK–cell-shared effectors peaked on Day 6, and then declined by Day 9 after the second cyclophosphamide injection and correlated inversely with the expression of the regulatory T cell (Treg) marker Foxp3. Sustained tumor regression leading to tumor ablation was achieved after several cyclophosphamide treatment cycles. Tumor ablation required CD8⁺ T cells, as shown by immunodepletion studies, and was associated with immunity to re-challenge with GL261 glioma cells, but not B16-F10 melanoma or Lewis lung carcinoma cells. Rejection of GL261 tumor re-challenge was associated with elevated CTLs in blood and increased CTL infiltration in tumors, consistent with the induction of long-term, specific CD8⁺ T-cell anti-GL261 tumor memory. Co-depletion of CD8⁺ T cells and NK cells did not inhibit tumor regression beyond CD8⁺ T-cell depletion alone, suggesting that the metronomic cyclophosphamide-activated NK cells function via CD8a⁺ T cells. Taken together, these findings provide proof-of-concept that single-agent chemotherapy delivered on an optimized metronomic schedule can eradicate large, established tumors and induce long-term immune memory.

Impaired function of CD4+ T follicular helper (Tfh) cells associated with hepatocellular carcinoma progression

Background and Aims

CD4+ T follicular helper (Tfh) cells, a new subset of immune cells, have been demonstrated to be involved in the development and prognosis of tumors. However, their functional role in human hepatocellular carcinoma (HCC) is relatively unknown, and the detailed mechanisms in HCC development remain to be described.

Methods

A total of 85 HCC patients with hepatitis B virus (HBV) infection, 25 HBV-relative liver cirrhosis (LC) patients, and 20 healthy controls (HC) were randomly enrolled. Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion, B cell maturation) assays were used to analyze the properties of CXCR5+CD4+ T cells. In addition, the relationship between the frequency of CXCR5+CD4+ T cells and overall survival rates or disease-free survival rates was also analyzed by the Kaplan-Meier method.

Results

The frequency of circulating CXCR5+CD4+ T cells was significantly decreased in HCC patients compared with HBV-relative liver cirrhosis (LC) patients and healthy controls, and the decrease in circulating CXCR5+CD4+ T cells correlated with disease progression. The proportion of infiltrated CXCR5+CD4+ T cells was significantly decreased in tumor regions compared with nontumor regions. Furthermore, compared with healthy controls, the function of circulating CXCR5+CD4+ T cells in HCC was impaired, with reduced IL-21 secretion and dysfunction in promoting B cell maturation. Importantly, follow-up data indicated that a decreased frequency of circulating CXCR5+CD4+ T cells was also associated with reduced disease-free survival time in HCC patients.

Conclusions

Impairment of CD4+ T follicular helper cells may influence the development of HBV-associated HCC. Decreased CD4+ T follicular helper cells may represent a potential prognostic marker and serve as a novel therapeutic target for HCC patients.

Expression of indoleamine 2,3-dioxygenase and infiltration of FOXP3+ regulatory T cells are associated with aggressive features of papillary thyroid microcarcinoma

BACKGROUND

Indoleamine 2,3-dioxygenase (IDO) is overexpressed in many different types of tumor and is associated with activation of FOXP3+ regulatory T cells (Treg cells) and downregulation of cytotoxic cellular immunity in the tumor microenvironment. It has been suggested that IDO inhibitors can be utilized as an effective therapeutic agent against human cancers. However, the expression of IDO and its association with tumor-infiltrating lymphocytes (TILs) remain unclear in papillary thyroid microcarcinoma (PTMC).

METHODS

Immunohistochemical staining for IDO expression was performed on 124 PTMC samples. TIL subsets (CD3+, CD8+, and FOXP3+ T cells) were counted in serial sections. The relationships between the expression of IDO and infiltration of TIL subsets, as well as the relationships between these immunomodulating factors and clinicopathologic parameters of PTMCs, were analyzed.

RESULTS

There was a significant correlation between IDO expression and reduced CD3+ TIL and increased FOXP3+ TIL. IDO expression was found in 31% of PTMC and was associated with aggressive clinicopathologic features of the tumor such as extrathyroidal extension (ETE) and multifocality. High infiltration of FOXP3+ Treg cells in the tumor was associated with lymph node metastasis, ETE, and multifocality. Furthermore, high FOXP3/CD8+ ratio was associated with multifocality and lymph node metastasis, and high FOXP3+/CD3+ ratio was related to ETE and multifocality. In multivariate analyses, IDO expression was found to be an independent predictive factor for ETE and tumor multifocality.

CONCLUSIONS

IDO expression and infiltration of FOXP3+ Treg cells were closely related to each other and were associated with aggressive features of PTMC, suggesting that disruption of antitumor immunity by IDO expression, and thus, infiltration of FOXP3+ Treg cells may contribute to tumor progression in PTMC.

Oncogene withdrawal engages the immune system to induce sustained cancer regression

The targeted inactivation of a single oncogene can induce dramatic tumor regression, suggesting that cancers are “oncogene addicted.” Tumor regression following oncogene inactivation has been thought to be a consequence of restoration of normal physiological programs that induce proliferative arrest, apoptosis, differentiation, and cellular senescence. However, recent observations illustrate that oncogene addiction is highly dependent upon the host immune cells. In particular, CD4⁺ helper T cells were shown to be essential to the mechanism by which MYC or BCR-ABL inactivation elicits “oncogene withdrawal.” Hence, immune mediators contribute in multiple ways to the pathogenesis, prevention, and treatment of cancer, including mechanisms of tumor initiation, progression, and surveillance, but also oncogene inactivation-mediated tumor regression. Data from both the bench and the bedside illustrates that the inactivation of a driver oncogene can induce activation of the immune system that appears to be essential for sustained tumor regression.

An essential role for the immune system in the mechanism of tumor regression following targeted oncogene inactivation

Tumors are genetically complex and can have a multitude of mutations. Consequently, it is surprising that the suppression of a single oncogene can result in rapid and sustained tumor regression, illustrating the concept that cancers are often "oncogene addicted." The mechanism of oncogene addiction has been presumed to be largely cell autonomous as a consequence of the restoration of normal physiological programs that induce proliferative arrest, apoptosis, differentiation, and/or cellular senescence. Interestingly, it has recently become apparent that upon oncogene inactivation, the immune response is critical in mediating the phenotypic consequences of oncogene addiction. In particular, CD4(+) T cells have been suggested to be essential to the remodeling of the tumor microenvironment, including the shutdown of host angiogenesis and the induction of cellular senescence in the tumor. However, adaptive and innate immune cells are likely involved. Thus, the effectors of the immune system are involved not only in tumor initiation, tumor progression, and immunosurveillance, but also in the mechanism of tumor regression upon targeted oncogene inactivation. Hence, oncogene inactivation may be an effective therapeutic approach because it both reverses the neoplastic state within a cancer cell and reactivates the host immune response that remodels the tumor microenvironment.

Various ways to improve whole cancer cell vaccines

Immunotherapy based on whole cancer cell vaccines is regarded as a promising avenue for cancer treatment. However, limited efficacy in the first human clinical trials calls for more optimized whole cancer cell vaccines and better patient selection. It is suggested that whole cancer cell vaccines consist preferably of immunogenically killed autologous cancer stem cells associated with dendritic cells. Adjuvants should stimulate both immune effector cells and memory cells, which could be achieved through their correct dosage and timing of administration. There are indications that whole cancer cell vaccination is less effective in patients who are immunocompromised, who have specific genetic defects in their immune or cancer cells, as well as in patients in an advanced cancer stage. However, such patients form the bulk of enrolled patients in clinical trials, prohibiting an objective evaluation of the true potential of whole cancer cell immunotherapy. Each key point will be discussed.

Identification of CDCA1-derived long peptides bearing both CD4+ and CD8+ T-cell epitopes: CDCA1-specific CD4+ T-cell immunity in cancer patients

We recently identified a novel cancer-testis antigen, cell division cycle associated 1 (CDCA1) using genome-wide cDNA microarray analysis, and CDCA1-derived cytotoxic T lymphocyte (CTL)-epitopes. In this study, we attempted to identify CDCA1-derived long peptides (LPs) that induce both CD4+ helper T (Th) cells and CTLs. We combined information from a recently developed computer algorithm predicting HLA class II-binding peptides with CDCA1-derived CTL-epitope sequences presented by HLA-A2 (A*02:01) or HLA-A24 (A*24:02) to select candidate CDCA1-LPs encompassing both Th cell epitopes and CTL-epitopes. We studied the immunogenicity of CDCA1-LPs and the cross-priming potential of LPs bearing CTL-epitopes in both human in vitro and HLA-class I transgenic mice in vivo. Then we analyzed the Th cell response to CDCA1 in head-and-neck cancer (HNC) patients before and after vaccination with a CDCA1-derived CTL-epitope peptide using IFN-γ enzyme-linked immunospot assays. We identified two CDCA1-LPs, CDCA1(39–64)-LP and CDCA1(55–78)-LP, which encompass naturally processed epitopes recognized by Th cells and CTLs. CDCA1-specific CTLs were induced through cross-presentation of CDCA1-LPs in vitro and in vivo. In addition, CDCA1-specific Th cells enhanced induction of CDCA1-specific CTLs. Furthermore, significant frequencies of CDCA1-specific Th cell responses were detected after short-term in vitro stimulation of peripheral blood mononuclear cells (PBMCs) with CDCA1-LPs in HNC patients (CDCA1(39–64)-LP, 74%; CDCA1(55–78)-LP, 68%), but not in healthy donors. These are the first results demonstrating the presence of CDCA1-specific Th cell responses in HNC patients and underline the possible utility of CDCA1-LPs for propagation of both CDCA1-specific Th cells and CTLs.

Identification of immunogenic LY6K long peptide encompassing both CD4+ and CD8+ T-cell epitopes and eliciting CD4+ T-cell immunity in patients with malignant disease

Identification of peptides that activate both tumor-specific helper T (Th) cells and cytotoxic T lymphocytes (CTLs) are important for the induction of effective antitumor immune responses. We focused on a long peptide (LP) derived from lymphocyte antigen 6 complex locus K (LY6K) encompassing both candidate Th epitopes and a known CTL epitope. Using IFNγ ELISPOT assays as a marker of activated T cells, we studied the immunogenicity and cross-priming potential of LY6K-LP, assaying human immune cell responses in vitro and immunologic activities in HLA-A24 transgenic mice in vivo. We identified LY6K_172–191-LP as an effective immunogen spanning naturally processed epitopes recognized by T helper type 1 (Th1) cells and CTLs. LY6K-specific CTLs were induced through cross-presentation of LY6K_172–191-LP in vitro and in vivo. In addition, LY6K_172–191-LP enhanced induction of LY6K-specific CTLs among the peripheral blood mononuclear cells (PBMCs) of head-and-neck malignant tumor (HNMT) patients. LY6K_172–191-LP-specific Th1 immunologic response following 1 week in vitro stimulation of PBMCs with LY6K_172–191-LP were detected in 16 of 21 HNMT patients (76%) vaccinated with CTL-epitope peptides and 1 of 11 HNMT patients (9%) prior to vaccination, but not in 9 healthy donors. Our results are the first to demonstrate the presence of LY6K-specific Th1 cell responses in HNMT patients and underscore the possible utility of LY6K_172–191-LP for the induction and propagation of both LY6K-specific Th1 cells and CTLs.

Association of the autoimmune disease scleroderma with an immunologic response to cancer

Autoimmune diseases are thought to be initiated by exposures to foreign antigens that cross-react with endogenous molecules. Scleroderma is an autoimmune connective tissue disease in which patients make antibodies to a limited group of autoantigens, including RPC1, encoded by the POLR3A gene. As patients with scleroderma and antibodies against RPC1 are at increased risk for cancer, we hypothesized that the "foreign" antigens in this autoimmune disease are encoded by somatically mutated genes in the patients' incipient cancers. Studying cancers from scleroderma patients, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to RPC1 but not in eight patients without antibodies to RPC1. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations triggered cellular immunity and cross-reactive humoral immune responses. These results offer insight into the pathogenesis of scleroderma and provide support for the idea that acquired immunity helps to control naturally occurring cancers.

Tumour-infiltrating CD8+ lymphocytes as an independent predictive factor for pathological complete response to primary systemic therapy in breast cancer

Background:

Tumour-infiltrating lymphocytes (TILs) are known to be associated with response to primary systemic therapy (PST) in breast cancer. This study was conducted to assess the association of TIL subsets with pathological complete response (pCR) after PST in breast cancer in relation to breast cancer subtype, breast cancer stem cell (BCSC) phenotype and epithelial–mesenchymal transition (EMT).

Methods:

The pre-chemotherapeutic biopsy specimens of 153 breast cancer patients who underwent surgical resection after anthracycline- or anthracycline/taxane-based PST were analysed. TIL subsets (CD4+, CD8+, and FOXP3+ TILs), BCSC phenotype, and the expression of EMT markers were evaluated by immunohistochemistry and were correlated with pCR after PST.

Results:

Infiltration of CD4+ and CD8+ T lymphocytes was closely correlated with BCSC phenotype and EMT. High levels of CD4+, CD8+, and FOXP3+ TILs were associated with pCR, and CD8+ TILs were found to be an independent predictive factor for pCR. In addition, CD8+ TILs were associated with pCR irrespective of breast cancer subtype, CD44+/CD24− phenotype, EMT, and chemotherapeutic regimen in subgroup analyses.

Conclusion:

These findings indicate that CD8+ cytotoxic T lymphocytes are a key component of TILs associated with chemo-response and can be used as a reliable predictor of response to anthracycline- or anthracycline/taxane-based PST in breast cancer.

Review article: antitumoural immunity in colorectal cancer - current and potential future implications in clinical practice

BACKGROUND

Most of the current research in gastrointestinal oncology is focused on biology of cancer itself, but there is growing interest in the patient's immune system response and its relation with cancer cells.

AIM

To review the impact of the antitumoural immune response on epidemiology, prognosis and treatment of colorectal cancer.

METHODS

Search of the literature published in English using the PubMed database.

RESULTS

The role of the immune system in the antitumoural immunosurveillance is clearly supported by the increased incidence of colorectal cancer and adenomatous polyps in immunosuppressed patients. Moreover, the degree of infiltration of the tumours by the immune cells has been shown to be a strong prognostic factor of both disease recurrence and survival. The immune system plays an important role in the chemotherapy-induced cell death. New therapeutic strategies targeting the antitumoural immunity are being currently investigated with promising results.

CONCLUSION

Better knowledge of antitumoural immune system can have a major impact on patients' management in daily clinical practice. Colorectal cancer screening is an important issue in immunosuppressed patients, and recommendations should be refined for selected high-risk patients. The use of an immune score to guide the therapeutic strategies in the adjuvant setting should be supported. Further and larger clinical trials are necessary to accelerate the development of innovative immune therapies.

Identification of promiscuous KIF20A long peptides bearing both CD4+ and CD8+ T-cell epitopes: KIF20A-specific CD4+ T-cell immunity in patients with malignant tumor

PURPOSE

To identify long peptides (LP) derived from a novel tumor-associated antigen (TAA), kinesin family member 20A (KIF20A), which induce tumor-specific T-helper type 1 (TH1) cells and CTLs.

EXPERIMENTAL DESIGN

We combined information from a recently developed computer algorithm predicting HLA class II-binding peptides with KIF20A-derived CTL-epitope sequences presented by HLA-A2 (A*02:01) or HLA-A24 (A*24:02) to select candidate promiscuous TH1-cell epitopes containing CTL epitopes. Peripheral blood mononuclear cells (PBMC) derived from healthy donors or patients with head-and-neck malignant tumor (HNMT) were used to study the immunogenicity of KIF20A-LPs, and the in vitro cross-priming potential of KIF20A-LPs bearing CTL epitopes. We used HLA-A24 transgenic mice to address whether vaccination with KIF20A-LP induces efficient cross-priming of CTLs in vivo. The TH1-cell response to KIF20A-LPs in HNMT patients receiving immunotherapy with TAA-derived CTL-epitope peptides was analyzed using IFN-γ enzyme-linked immunospot assays.

RESULTS

We identified promiscuous KIF20A-LPs bearing naturally processed epitopes recognized by CD4(+) T cells and CTLs. KIF20A-specific CTLs were induced by vaccination with a KIF20A-LP in vivo. KIF20A expression was detected in 55% of HNMT by immunohistochemistry, and significant frequencies of KIF20A-specific TH1 cell responses were detected after short-term in vitro stimulation of PBMCs with KIF20A-LPs in 50% of HNMT patients, but not in healthy donors. Furthermore, these responses were associated with KIF20A expression in HNMT tissues.

CONCLUSIONS

These are the first results showing the presence of KIF20A-specific TH1 cell responses in HNMT patients and underline the possible utility of KIF20A-LPs for propagation of TH1 cells and CTLs.

Targeting antitumor CD4 helper T cells with universal tumor-reactive helper peptides derived from telomerase for cancer vaccine

Current cancer immunotherapies predominantly rely on CD8(+) T cells to fight against tumors. However accumulative evidence showed that proinflammatory CD4(+) helper T cells are critical determinants of effective antitumor immunity. The utilization of universal tumor-reactive helper peptides from telomerase represents a powerful approach to the fully use of CD4(+) T cell-based immunotherapy.

Tumor-induced CD8+ T-cell dysfunction in lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs) and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

Polyfunctional CD4⁺ T cells are essential for eradicating advanced B-cell lymphoma after chemotherapy

The finding that many chemotherapeutic agents have immunostimulatory effects has provided the impetus to combine chemotherapy and immunotherapy for synergistic antitumor effects. However, the critical determinants of effective antitumor immunity after chemotherapy have not been defined. Here we report that adoptive transfer of tumor-specific CD4⁺ T cells after chemotherapy with cyclophosphamide gave rise to polyfunctional CD4⁺ effector cells, which in turn intensified the inflammatory milieu and enhanced the activation of CD8⁺ T cells in the tumor microenvironment. Although this combined chemoimmunotherapy initially resulted in progressive regression of advanced B-cell lymphoma, its therapeutic efficacy was not durable and most mice succumbed to late relapse. Notably, relapse was associated with acquisition of a tolerized phenotype in tumor-specific CD4⁺ T cells, characterized by overexpression of program death-1 (PD-1). Remarkably, effective antitumor immunity was maintained and cure became prevalent when polyfunctional CD4⁺ effector cells were prevented from undergoing PD-1-mediated tolerization, either by antibody blockade of the PD-1-PD-L1 pathway, or targeted ablation of PD-1 in tumor-specific CD4⁺ T cells. Our study suggests that tumor-reactive CD4⁺ T cells act as the "gatekeepers" of the host antitumor immunity in the postchemotherapy setting, thereby their functional status governs the choice between eradication versus regrowth of residual tumors.

Implication of tumor microenvironment in chemoresistance: tumor-associated stromal cells protect tumor cells from cell death

Tumor development principally occurs following the accumulation of genetic and epigenetic alterations in tumor cells. These changes pave the way for the transformation of chemosensitive cells to chemoresistant ones by influencing the uptake, metabolism, or export of drugs at the cellular level. Numerous reports have revealed the complexity of tumors and their microenvironment with tumor cells located within a heterogeneous population of stromal cells. These stromal cells (fibroblasts, endothelial or mesothelial cells, adipocytes or adipose tissue-derived stromal cells, immune cells and bone marrow-derived stem cells) could be involved in the chemoresistance that is acquired by tumor cells via several mechanisms: (i) cell-cell and cell-matrix interactions influencing the cancer cell sensitivity to apoptosis; (ii) local release of soluble factors promoting survival and tumor growth (crosstalk between stromal and tumor cells); (iii) direct cell-cell interactions with tumor cells (crosstalk or oncologic trogocytosis); (iv) generation of specific niches within the tumor microenvironment that facilitate the acquisition of drug resistance; or (v) conversion of the cancer cells to cancer-initiating cells or cancer stem cells. This review will focus on the implication of each member of the heterogeneous population of stromal cells in conferring resistance to cytotoxins and physiological mediators of cell death.