Influence of tumors on protective anti-tumor immunity and the effects of irradiation

Innate and adaptive immunity play important roles in the development and progression of cancer and it is becoming apparent that tumours can influence the induction of potentially protective responses in a number of ways. The prevalence of immunoregulatory T cell populations in the circulation and tumours of patients with cancer is increased, and the presence of these cells appears to present a major barrier to the induction of tumour immunity. One aspect of tumour-mediated immunoregulation which has received comparatively little attention is that which is directed towards natural killer (NK) cells, although evidence that the phenotype and function of NK cell populations are modified in patients with cancer is accumulating.Although the precise mechanisms underlying these localised and systemic immunoregulatory effects remain unclear, tumour-derived factors appear, in part at least, to be involved. The effects could be manifested by an altered function and/or via an influence on the migratory properties of individual cell subsets. A better insight into endogenous immunoregulatory mechanisms and the capacity of tumours to modify the phenotype and function of innate and adaptive immune cells might assist the development of new immunotherapeutic approaches and improve the management of patients with cancer.This article reviews current knowledge relating to the influence of tumours on protective anti-tumour immunity and considers the potential influence that radiation-induced effects might have on the prevalence, phenotype and function of innate and adaptive immune cells in patients with cancer

From Localized Mild Hyperthermia to Improved Tumor Oxygenation: Physiological Mechanisms Critically Involved in Oncologic Thermo-Radio-Immunotherapy.

(1) Background: Mild hyperthermia (mHT, 39-42 °C) is a potent cancer treatment modality when delivered in conjunction with radiotherapy. mHT triggers a series of therapeutically relevant biological mechanisms, e.g., it can act as a radiosensitizer by improving tumor oxygenation, the latter generally believed to be the commensurate result of increased blood flow, and it can positively modulate protective anticancer immune responses. However, the extent and kinetics of tumor blood flow (TBF) changes and tumor oxygenation are variable during and after the application of mHT. The interpretation of these spatiotemporal heterogeneities is currently not yet fully clarified. (2) Aim and methods: We have undertaken a systematic literature review and herein provide a comprehensive insight into the potential impact of mHT on the clinical benefits of therapeutic modalities such as radio- and immuno-therapy. (3) Results: mHT-induced increases in TBF are multifactorial and differ both spatially and with time. In the short term, changes are preferentially caused by vasodilation of co-opted vessels and of upstream normal tissue vessels as well as by improved hemorheology. Sustained TBF increases are thought to result from a drastic reduction of interstitial pressure, thus restoring adequate perfusion pressures and/or HIF-1α- and VEGF-mediated activation of angiogenesis. The enhanced oxygenation is not only the result of mHT-increased TBF and, thus, oxygen availability but also of heat-induced higher O2 diffusivities, acidosis- and heat-related enhanced O2 unloading from red blood cells. (4) Conclusions: Enhancement of tumor oxygenation achieved by mHT cannot be fully explained by TBF changes alone. Instead, a series of additional, complexly linked physiological mechanisms are crucial for enhancing tumor oxygenation, almost doubling the initial O2 tensions in tumors

From Localized Mild Hyperthermia to Improved Tumor Oxygenation: Physiological Mechanisms Critically Involved in Oncologic Thermo-Radio-Immunotherapy

(1) Background: Mild hyperthermia (mHT, 39-42 °C) is a potent cancer treatment modality when delivered in conjunction with radiotherapy. mHT triggers a series of therapeutically relevant biological mechanisms, e.g., it can act as a radiosensitizer by improving tumor oxygenation, the latter generally believed to be the commensurate result of increased blood flow, and it can positively modulate protective anticancer immune responses. However, the extent and kinetics of tumor blood flow (TBF) changes and tumor oxygenation are variable during and after the application of mHT. The interpretation of these spatiotemporal heterogeneities is currently not yet fully clarified. (2) Aim and methods: We have undertaken a systematic literature review and herein provide a comprehensive insight into the potential impact of mHT on the clinical benefits of therapeutic modalities such as radio- and immuno-therapy. (3) Results: mHT-induced increases in TBF are multifactorial and differ both spatially and with time. In the short term, changes are preferentially caused by vasodilation of co-opted vessels and of upstream normal tissue vessels as well as by improved hemorheology. Sustained TBF increases are thought to result from a drastic reduction of interstitial pressure, thus restoring adequate perfusion pressures and/or HIF-1α- and VEGF-mediated activation of angiogenesis. The enhanced oxygenation is not only the result of mHT-increased TBF and, thus, oxygen availability but also of heat-induced higher O$_{2}$ diffusivities, acidosis- and heat-related enhanced O$_{2}$ unloading from red blood cells. (4) Conclusions: Enhancement of tumor oxygenation achieved by mHT cannot be fully explained by TBF changes alone. Instead, a series of additional, complexly linked physiological mechanisms are crucial for enhancing tumor oxygenation, almost doubling the initial O$_{2}$ tensions in tumors

In Situ Prior Proliferation of CD4+ CCR6+ Regulatory T Cells Facilitated by TGF-β Secreting DCs Is Crucial for Their Enrichment and Suppression in Tumor Immunity

BACKGROUND: CD4(+)CD25(+) regulatory T cells (Tregs), a heterogeneous population, were enrichment in tumor mass and played an important role in modulating anti-tumor immunity. Recently, we reported a Treg subset, CCR6(+) Tregs but not CCR6(-)Tregs, were enriched in tumor mass and closely related to poor prognosis of breast cancer patients. However, the underlying mechanism remains elusive. Here, we carefully evaluate the enrichment of CCR6(+)Tregs in tumor mass during progression of breast cancer and explore its possible mechanism. METHODOLOGY/PRINCIPAL FINDINGS: The frequency of CCR6(+)Tregs in tumor infiltrating lymphocytes (TILs ) was analyzed at early stage and at late stage of tumor in a murine breast cancer model by FACS respectively. The expansion of CCR6(+)Tregs and their CCR6(-) counterpart in tumor mass were determined by BrdU incorporation assay. The effect and its possible mechanism of tumor-resident antigen presenting cells (APCs) on the proliferation of CCR6(+)Tregs also were evaluated. The role of local expansion of CCR6(+)Tregs in their enrichment and suppression in vivo also was evaluated in adoptive cell transfer assay. We found that the prior enrichment of CCR6(+)Tregs but not CCR6(-)Tregs in tumor mass during progression of murine breast cancer, which was dependent on the dominant proliferation of CCR6(+) Tregs in situ. Further study demonstrated that tumor-resident DCs triggered the proliferation of CCR6(+)Treg cells in TGF-β dependent manner. Adoptive transfer of CCR6(+)Tregs was found to potently inhibit the function of CD8(+)T cells in vivo, which was dependent on their proliferation and subsequently enrichment in tumor mass. CONCLUSIONS/SIGNIFICANCE: Our finding suggested that CCR6(+) Tregs, a distinct subset of Tregs, exert its predominant suppressive role in tumor immunity through prior in situ expansion, which might ultimately provide helpful thoughts for the designing of Treg-based immunotherapy for tumor in the future

Natural Killer Cell Mediated Cytotoxic Responses in the Tasmanian Devil

The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against DFTD cells and foreign tumour cells. The two Tasmanian devils immunised with irradiated DFTD cells did not form cytotoxic or humoral responses against DFTD cells, even after multiple immunisations. However, following immunisation with xenogenic K562 cells, devils did produce cytotoxic responses and antibodies against this foreign tumour cell line. The cytotoxicity appeared to occur through the activity of natural killer (NK) cells in an antibody dependent manner. Classical NK cell responses, such as innate killing of DFTD and foreign cancer cells, were not observed. Cells with an NK-like phenotype comprised approximately 4 percent of peripheral blood mononuclear cells. The results of this study suggest that Tasmanian devils have NK cells with functional cytotoxic pathways. Although devil NK cells do not directly recognise DFTD cancer cells, the development of antibody dependent cell-mediated cytotoxicity presents a potential pathway to induce cytotoxic responses against the disease. These findings have positive implications for future DFTD vaccine research

SPAG5 as a prognostic biomarker and chemotherapy sensitivity predictor in breast cancer: a retrospective, integrated genomic, transcriptomic, and protein analysis

Background: Although the use of proliferation markers/profiles has been recommended when choosing the appropriate systemic-treatment for breast cancer (BC), the best molecular-marker/test that should be used needs to be identified. Methods: To identify factors that drive proliferation and its associated features in BC an artificial neural network (ANN) based integrative data-mining methodology was applied to three cohorts [(Nottingham-discovery (ND), Uppsala and METABRIC (Molecular Taxonomy of Breast Cancer International Consortium)]. The most prominent genes in the resulting interactome-map were then identified. Given that SPAG5 was associated with many features of proliferation, featured prominently in the interactome-map and has a fundamental role in mitotic-progression,, we hypothesized that it could be a better indicator of proliferation activity. (BC). Subsequently to test if it could provide a more accurate guide for the delivery of systemic therapies in BC, we investigated the clinico-pathological utility of SPAG5: gene copy number aberrations (CNAs); mRNA and protein expression, in over 10,000 BCs. Integrated analysis of SPAG5-gene CNAs, transcript and protein expression was conducted in the ND cohort (n=171) and validated in the METABRIC cohort (n=1980). In addition, the associations of SPAG5 CNAs, transcript and/or protein with BC specific survival (BCSS), disease free survival (DFS) and/or distant relapse free survival (DRFS) were analysed in multiple cohorts including Uppsala (n=249), METABRIC, three-untreated lymph node (LN) negative cohorts (n=684), a combined multicentre clinical data set (n=5439), Nottingham historical early-stage-primary BC (Nottingham-HES-BC; n=1650), Nottingham oestrogen receptor (ER) negative BC (n=697), Nottingham anthracycline-Neoadjuvant-chemotherapy (Nottingham-AC-Neo-ACT; n=200), and MD Anderson Cancer Centre Taxane/anthracycline (MDACC-T/AC-Neo-ACT; n=508) cohorts. The association of SPAG5 transcript and protein expression with pathological response rate (pCR) were also tested in [MDACC-T/AC-Neo-ACT (n=508) and the phase II trial NCT00455533; n=253)] and [Nottingham-AC-Neo-ACT (n=200)] cohorts; respectively. Findings: SPAG5 gene gain/amplification at the Ch17q11·2 locus was found in 10.4% of BC (206/1980 (; METABRIC) and was reported in 19·4% of PAM50-HER2 (46/237) and 17·8% of PAM50-LumB (87/488). SPAG5-CNA gain/amplification and high SPAG5-transcript and SPAG5-protein were associated with increased risk of death from BC [Uppsala; (HR (CI 95%): 1·50 (1·18-1·92); p=0·00010, METABRIC; (HR (CI 95%): 1·68 (1·40-2·01) p<0·0001), and Nottingham-HSE-BC; (HR (CI 95%): 1·68 (1·32-2·12), p<0·0001); respectively]. Multivariable Cox regression models, including other validated-prognostic factors, (Uppsala: age, size, LN-stage, genomic grade index (GGI), ER, TP53 mutation and MKi67; METABRIC: age, size, LN-stage, histologic-grade, ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), hormone-therapy, chemotherapy, interaction term of SPAG5 and both chemotherapyy and hormonotherapy; Desmedt-untreated LN- cohort: ER, Nottingham prognostic index (NPI), 76-gene prognostic signature (Veridex) and Adjuvant-Online (AOL); Nottingham-HES-BC: menopausal status, size, LN- stage, histologic-grade, ER, PR, HER2, ki67, hormone-therapy, chemotherapy, interaction term of SPAG5 and both chemotherapy[y and hormonotherapy), showed that high SPAG5-transcript and high SPAG5-protein were associated with shorter BCSS [Uppsala: (HR (CI 95%): 1·62 (1·03-2·53) p=0·036); METABRIC: (HR (CI 95%): 1·27 (1·02-1·58) p=0·034); Desmedt-untreated LN- cohort: (HR (CI 95%): 2·34 (1·24-4·42) p=0·0090), and Nottingham-HES-BC (HR (CI 95%): 1·73 (1·23-2·46) p=0·0020); respectively]. In ER-negative-BC with high SPAG5-protein, administration of anthracycline-adjuvant-chemotherapy had reduced the risk of death by 60% compared to chemotherapy-naive (HR (95% CI): 0·37 (0·20-0·60); p=0·0010). A multivariable Cox regression analysis, which included other validated prognostic factors for chemotherapy (e.g., menopausal status, size, lymph node stage, histologic grade, ER, PR, HER2, Bcl2, chemotherapy, interaction term of SPAG5 and both chemotherapy[y), revealed that SPAG5-transcript+ was independently associated with decreased risk of DRFS after receiving Taxane/anthracycline-Neo-ACT [MDACC-T/AC-Neo-ACT: (HR (CI 95%): 0·68 (0·48-0·97); p=0·0070)]. In multivariable logistic regression analysis, both SPAG5-transcript+ and SPAG5-protein+ and were independent predictors for higher pCR after combination-cytotoxic chemotherapy [MDACC-T/AC-Neo-ACT: (OR (95% CI) 1·71 (1·07-2·74); p=0·024), and Nottingham-AC-Neo-AC: (OR (95% CI): 8·75 (2·42-31); p=0·0010); respectively]. Interpretation: SPAG5 is a novel amplified gene on Ch17q11.2 in PAM50-LumB and PAM-HER2 BC, and its transcript and protein products are independent prognostic and predictive biomarkers, with potential clinical utility as a biomarker for combination cytotoxic chemotherapy sensitivity, especially in ER- BC

Safety and efficacy of autologous haematopoietic stem-cell transplantation with low-dose cyclophosphamide mobilisation and reduced intensity conditioning versus standard of care in refractory Crohn's disease (ASTIClite): an open-label, multicentre, randomised controlled trial

Background: A previous controlled trial of autologous haematopoietic stem-cell transplantation (HSCT) in patients with refractory Crohn's disease did not meet its primary endpoint and reported high toxicity. We aimed to assess the safety and efficacy of HSCT with an immune-ablative regimen of reduced intensity versus standard of care in this patient population. Methods: This open-label, multicentre, randomised controlled trial was conducted in nine National Health Service hospital trusts across the UK. Adults (aged 18–60 years) with active Crohn's disease on endoscopy (Simplified Endoscopic Score for Crohn's Disease [SES-CD] ulcer sub-score of ≥2) refractory to two or more classes of biological therapy, with no perianal or intra-abdominal sepsis or clinically significant comorbidity, were recruited. Participants were centrally randomly assigned (2:1) to either HSCT with a reduced dose of cyclophosphamide (intervention group) or standard care (control group). Randomisation was stratified by trial site by use of random permuted blocks of size 3 and 6. Patients in the intervention group underwent stem-cell mobilisation (cyclophosphamide 1 g/m2 with granulocyte colony-stimulating factor (G-CSF) 5 μg/kg) and stem-cell harvest (minimum 2·0 × 106 CD34+ cells per kg), before conditioning (fludarabine 125 mg/m2, cyclophosphamide 120 mg/kg, and rabbit anti-thymocyte globulin [thymoglobulin] 7·5 mg/kg in total) and subsequent stem-cell reinfusion supported by G-CSF. Patients in the control group continued any available conventional, biological, or nutritional therapy. The primary outcome was absence of endoscopic ulceration (SES-CD ulcer sub-score of 0) without surgery or death at week 48, analysed in the intention-to-treat population by central reading. This trial is registered with the ISRCTN registry, 17160440. Findings: Between Oct 18, 2018, and Nov 8, 2019, 49 patients were screened for eligibility, of whom 23 (47%) were randomly assigned: 13 (57%) to the intervention group and ten (43%) to the control group. In the intervention group, ten (77%) participants underwent HSCT and nine (69%) reached 48-week follow-up; in the control group, nine (90%) reached 48-week follow-up. The trial was halted in response to nine reported suspected unexpected serious adverse reactions in six (46%) patients in the intervention group, including renal failure due to proven thrombotic microangiopathy in three participants and one death due to pulmonary veno-occlusive disease. At week 48, absence of endoscopic ulceration without surgery or death was reported in three (43%) of seven participants in the intervention group and in none of six participants in the control group with available data. Serious adverse events were more frequent in the intervention group (38 in 13 [100%] patients) than in the control group (16 in four [40%] patients). A second patient in the intervention group died after week 48 of respiratory and renal failure. Interpretation: Although HSCT with an immune-ablative regimen of reduced intensity decreased endoscopic disease activity, significant adverse events deem this regimen unsuitable for future clinical use in patients with refractory Crohn's disease. Funding: Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research partnership

Elevated Levels of Circulating Hsp70 and an Increased Prevalence of CD94+/CD69+ NK Cells Is Predictive for Advanced Stage Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the second most frequently diagnosed tumor worldwide. Despite the clinical progress which has been achieved by multimodal therapies, including radiochemotherapy, and immune checkpoint inhibitor blockade, the overall survival of patients with advanced-stage NSCLC remains poor, with less than 16 months. It is well established that many aggressive tumor entities, including NSCLC, overexpress the major stress-inducible heat shock protein 70 (Hsp70) in the cytosol, present it on the plasma membrane in a tumor-specific manner, and release Hsp70 into circulation. Although high Hsp70 levels are associated with tumor aggressiveness and therapy resistance, membrane-bound Hsp70 can serve as a tumor-specific antigen for Hsp70-primed natural killer (NK) cells, expressing the C-type lectin receptor CD94, which is part of the activator receptor complex CD94/NKG2C. Therefore, we investigated circulating Hsp70 levels and changes in the composition of peripheral blood lymphocyte subsets as potential biomarkers for the advanced Union for International Cancer Control (UICC) stages in NSCLC. As expected, circulating Hsp70 levels were significantly higher in NSCLC patients compared to the healthy controls, as well as in patients with advanced UICC stages compared to those in UICC stage I. Smoking status did not influence the circulating Hsp70 levels significantly. Concomitantly, the proportions of CD4+ T helper cells were lower compared to the healthy controls and stage I tumor patients, whereas that of CD8+ cytotoxic T cells was progressively higher. The prevalence of CD3&minus;/CD56+, CD3&minus;/NKp30, CD3&minus;/NKp46+, and CD3&minus;/NKG2D+ NK cells was higher in stage IV/IIIB of the disease than in stage IIIA but were not statistically different from that in healthy individuals. However, the proportion of NK cells expressing CD94 and the activation/exhaustion marker CD69 significantly increased in higher tumor stages compared with stage I and the healthy controls. We speculate that although elevated circulating Hsp70 levels might promote the prevalence of CD94+ NK cells in patients with advanced-stage NSCLC, the cytolytic activity of these NK cells also failed to control tumor growth due to insufficient support by pro-inflammatory cytokines from CD4+ T helper cells. This hypothesis is supported by a comparative multiplex cytokine analysis of the blood in lung cancer patients with a low proportion of CD4+ T cells, a high proportion of NK cells, and high Hsp70 levels versus patients with a high proportion of CD4+ T cells exhibiting lower IL-2, IL-4, IL-6, IFN-&gamma;, granzyme B levels