Distinct innate and adaptive immunity phenotypic profile at the circulating single-cell level in Psoriatic Arthritis.

Mass cytometry was employed to investigate 47 circulating leukocyte subsets in patients with active psoriatic arthritis (PsA, n = 16) compared to healthy controls (n = 13), seropositive (RF and/or anti-CCP, n = 12) and seronegative (n = 9) RA patients. Comparing PsA to controls, different cell frequencies were found in both innate and adaptive immunity cell subsets, as well as in cells bridging innate and adaptive immunity. In some T cell subsets increased costimulatory molecules' expression in PsA, was also noted.No changes were observed in patients who remained disease-active after 3 months of treatment, in contrast to those who achieved remission/low-disease activity. Comparing PsA to seropositive RA, elevated frequencies of naïve and activated CD8+ T cells, B cells, MAIT/iNKT and ILCs were found, while the opposite was the case for terminal effector, senescent, and Th2-like cells. Strikingly, the composition of the leukocyte pool in PsA was comparable to seronegative RA, providing evidence for the pathogenetic similarities between these two entities.

Small Extracellular Vesicles in Pre-Therapy Plasma Predict Clinical Outcome in Non-Small-Cell Lung Cancer Patients.

The potential use of plasma-derived small extracellular vesicles (sEV) as predictors of response to therapy and clinical outcome in chemotherapy-naïve patients with non-small-cell lung cancer (NSCLC) was explored. sEV were isolated by size-exclusion chromatography from the plasma of 79 chemotherapy-naïve NSCLC patients and 12 healthy donors (HD). sEV were characterized with regard to protein content, particle size, counts by qNano, morphology by transmission electron microscopy, and molecular profiles by Western blots. PD-1 and PD-L1 expression on circulating immune cells was analysed by flow cytometry. Pre-treatment levels of total sEV protein (TEP) were correlated with overall (OS) and progression-free survival (PFS). The sEV numbers and protein levels were significantly elevated in the plasma of NSCLC patients compared to HD (p = 0.009 and 0.0001, respectively). Baseline TEP levels were higher in patients who developed progressive disease compared to patients with stable disease (p = 0.007 and 0.001, stage III and IV, respectively). Patient-derived sEV were enriched in immunosuppressive proteins as compared to proteins carried by sEV from HD. TEP levels were positively correlated with CD8+PD-1+ and CD8+PD-L1+ circulating T cell percentages and were independently associated with poorer PFS (p < 0.00001) and OS (p < 0.00001). Pre-therapy sEV could be useful as non-invasive biomarkers of response to therapy and clinical outcome in NSCLC.

Epithelial-to-mesenchymal Transition Heterogeneity of Circulating Tumor Cells and Their Correlation With MDSCs and Tregs in HER2-negative Metastatic Breast Cancer Patients.

BACKGROUND: To investigate the correlation between circulating tumor cells (CTCs) bearing cancer stem cell (CSC) and epithelial-to-mesenchymal (EMT) phenotypes and the different immunosuppressive cells in peripheral blood of patients with metastatic breast cancer (mBC). MATERIALS AND METHODS: Blood was obtained from 38 pre-treated patients with mBC before a new line of treatment. CTC detection and characterization was performed by triple immunofluorescent staining, while Myeloid-derived Suppressor Cells (MDSCs) and T regulatory cells (Tregs) were analyzed by multi-flow cytometry. RESULTS: CTCs were detected in 16 (42.1%) of patients. Based on the co-expression of ALDH1, TWIST and CK, CTCs revealed an important heterogeneity: CTCs with a CSC/partial-EMT, CSC/Epithelial-like, non-CSC/partial-EMT and non-CSC/Epithelial-like phenotype were detected in 7 (18.4%), 7 (18.4%), 1 (1.4%) and 9 (23.7%) of patients, respectively. Immunophenotyping of MDSCs identified 2 monocytic [M-MDSCs; CD14+CD15+CD11b+CD33+HLA-DR-Lin- (CD14+CD15+) and CD14+CD15-CD11b+CD33+ HLA-DR-Lin- (CD14+CD15-)] and one granulocytic [G-MDSCs; CD14-CD15+CD11b+CD33+HLA-DR-Lin- (CD14- CD15+)] subpopulations, expressing inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS), respectively. Patients with detectable CTCs had a higher frequency of Tregs (CD3+CD4+CD25high; p=0.022) whereas a positive correlation was found between CTC counts and the percentage of Tregs (p=0.005) and CD14+CD15+ M-MDSCs (p=0.024). Patients with a partial-EMT phenotype had a higher frequency of CD14+CD15+ M-MDSCs (p=0.023). Patients harboring the non-CSC/epithelial-like CTC subpopulation had an increased frequency of CD14-CD15+ G-MDSCs (p=0.020), along with decreased levels of CD3+CD4+CD25high FoxP3+ Tregs (p=0.020). CONCLUSION: These findings provide evidence that CTCs in ER+/HER2- mBC patients may be under the control of the immune system and various immune escape mechanisms might be involved during the different stages of their biological evolution.

Clinical activity of a htert (vx-001) cancer vaccine as post-chemotherapy maintenance immunotherapy in patients with stage IV non-small cell lung cancer: final results of a randomised phase 2 clinical trial.

BACKGROUND: The cancer vaccine Vx-001, which targets the universal tumour antigen TElomerase Reverse Transcriptase (TERT), can mount specific Vx-001/TERT572 CD8 + cytotoxic T cells; this immune response is associated with improved overall survival (OS) in patients with advanced/metastatic non-small cell lung cancer (NSCLC). METHODS: A randomised, double blind, phase 2b trial, in HLA-A*201-positive patients with metastatic, TERT-expressing NSCLC, who did not progress after first-line platinum-based chemotherapy were randomised to receive either Vx-001 or placebo. The primary endpoint of the trial was OS. RESULTS: Two hundred and twenty-one patients were randomised and 190 (101 and 89 patients in the placebo and the Vx-001 arm, respectively) were analysed for efficacy. There was not treatment-related toxicity >grade 2. The study did not meet its primary endpoint (median OS 11.3 and 14.3 months for the placebo and the Vx-001, respectively; p = 0.86) whereas the median Time to Treatment Failure (TTF) was 3.5 and 3.6 months, respectively. Disease control for >6months was observed in 30 (33.7%) and 26 (25.7%) patients treated with Vx-001 and placebo, respectively. There was no documented objective CR or PR. Long lasting TERT-specific immune response was observed in 29.2% of vaccinated patients who experienced a significantly longer OS compared to non-responders (21.3 and 13.4 months, respectively; p = 0.004). CONCLUSION: Vx-001 could induce specific CD8+ immune response but failed to meet its primary endpoint. Subsequent studies have to be focused on the identification and treatment of subgroups of patients able to mount an effective immunological response to Vx-001. CLINICAL TRIAL REGISTRATION: NCT01935154.

Myeloid-Derived Suppressor Cells: Major Figures that Shape the Immunosuppressive and Angiogenic Network in Cancer.

Myeloid-derived suppressor cells (MDSCs) constitute a vast population of immature myeloid cells implicated in various conditions. Most notably, their role in cancer is of great complexity. They exert immunosuppressive functions like hampering cancer immunity mediated by T lymphocytes and natural killer cells, while simultaneously they can recruit T regulatory cells to further promote immunosuppression, thus shielding tumor cells against the immune defenses. In addition, they were shown to support tumor invasion and metastasis by inducing vascularization. Yet again, in order to exert their angiogenic activities, they do have at their disposal a variety of occasionally overlapping mechanisms, mainly driven by VEGF/JAK/STAT signaling. In this concept, they have risen to be a rather attractive target for therapies, including depletion or maturation, so as to overcome cancer immunity and suppress angiogenic activity. Even though, many studies have been conducted to better understand these cells, there is much to be done yet. This article hopes to shed some light on the paradoxal complexity of these cells, while elucidating some of the key features of MDSCs in relation to immunosuppression and, most importantly, to the vascularization processes, along with current therapeutic options in cancer, in relation to MDSC depletion.

Characterization of DLL3-positive circulating tumor cells (CTCs) in patients with small cell lung cancer (SCLC) and evaluation of their clinical relevance during front-line treatment.

OBJECTIVES: The aim of the study was to characterize and evaluate the presence of DLL3-positive Circulating Tumor Cells (CTCs) in SCLC patients receiving front-line chemotherapy and assess their clinical relevance. MATERIALS AND METHODS: Peripheral blood was obtained from treatment-naïve patients with SCLC (n = 108 patients), after one etoposide/platinum cycle (n = 68 patients) and on disease progression (n = 48 patients). Immunofluorescence staining using antibodies against the DLL3, cytokeratins (CK), CD45 and vimentin (Vim) was used for the detection and characterization of CTCs. RESULTS: Before treatment, 74.1% of patients had detectable DLL3+/CD45- CTCs. One-treatment cycle significantly decreased both the detection rate (p < 0.001) and the absolute number (p < 0.001) of DLL3+/CD45- CTCs. Triple immunofluorescence staining using anti-CK, anti-Vim and anti-DLL3 antibodies revealed an important CTC heterogeneity since DLL3 could be detected in Vim+, Vim-, CK+ and CK- CTCs. On disease progression, both the detection rate and the absolute number of DLL3+/CD45- CTCs were significantly increased compared to post-1st cycle values (p < 0.001 and p = 0.002, respectively). In addition, 22.7% of patients had detectable DLL3+/CD45- cells which could not be captured by the CellSearch assay. In multivariate analysis, the detection of DLL3+/CD45- CTCs at baseline was significantly associated with decreased progression-free survival (HR = 10.8; p = 0.005) whereas their detection on disease progression was associated with decreased overall survival (HR: 28.2; p = 0.016). CONCLUSIONS: These findings demonstrate an important heterogeneity of CTCs, based on the expression of CK, Vim and DLL3, in patients with SCLC and the changes of DLL3+/CD45- CTCs during treatment seem to be a dynamic biomarker associated with patients' clinical outcome.

CD8+ PD-1+ T-cells and PD-L1+ circulating tumor cells in chemotherapy-naïve non-small cell lung cancer: towards their clinical relevance?

BACKGROUND: Since tumor cells may escape from immune surveillance through the programmed cell death 1 (PD-1)/programmed death ligand (PD-L)1 axis, this study was designed in order to evaluate whether there is a correlation between the levels of PD-1+ and PD-L1+-expressing immune cells (ICs) and circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Peripheral blood was obtained from 37 chemotherapy-naïve patients with metastatic NSCLC before treatment. PD-1 and PD-L1 expression was evaluated (1) on ICs with anti-tumor function (CD4+ and CD8+ T-cells, B-cells, monocytes/dendritic cells) using flow cytometry, (2) on CTCs by immunofluorescence and (3) on cells from tumor tissues by immunohistochemistry. The levels of PD-1+ and PD-L1+-expressing ICs were correlated with progression-free survival (PFS). RESULTS: The presence of PD-1+ CD8+ cells, with reduced interferon (IFN)-γ expression, but not other ICs, were positively correlated with PD-L1+ CTCs (p < 0.04). Increased percentages of PD-1+ CD8+ T-cells, were associated with a worse response to treatment (p = 0.032) and shorter PFS (p = 0.023) which, in multivariate analysis, was revealed as an independent predictor for decreased PFS [hazard ratio (HR): 4.1, p = 0.0007]. CONCLUSION: The results of the current study, for first time, provide evidence for a possible interaction between ICs and CTCs in NSCLC patients via the PD-1/PD-L1 axis and strongly support that the levels of PD-1+ CD8+ in these patients may be of clinical relevance.

Evaluation of PD-L1/PD-1 on circulating tumor cells in patients with advanced non-small cell lung cancer.

BACKGROUND: Circulating tumor cells (CTCs) could escape from the immune system through the programmed death-ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) axis leading to the development of metastasis. The current study investigated the expression of PD-1/PD-L1 on CTCs isolated from non-small cell lung cancer (NSCLC) patients treated with chemotherapy. PATIENTS AND METHODS: CTCs were isolated from 30 chemo-naïve stage IV NSCLC patients before and after front-line chemotherapy using the ISET filtration platform. CTCs were detected by Giemsa and immunofluorescence (IF) staining. Samples were analyzed with the ARIOL system. RESULTS: Giemsa staining revealed that 28 (93.3%) out of 30 and 9 (81.8%) out of 11 patients had detectable CTCs at baseline and after the third chemotherapy cycle, respectively. Cytokeratin (CK)+/CD45- CTCs by IF could be detected in 17 of 30 (56.7%) patients at baseline and in 8 of 11 (72.7%) after the third chemotherapy cycle. Spearman analysis revealed a significant correlation (p = 0.001) between Giemsa-positive and IF-positive (CK+/CD45-) CTCs. At baseline, PD-1 and PD-L1 expression was observed in 53% and in 47% CK-positive patients, respectively. After the third treatment cycle the corresponding numbers were 13% and 63% respectively. Median progression-free survival (PFS) was significantly shorter in patients with >3 PD-1(+) CTCs at baseline compared with those with <3 PD-1(+) CTCs (p = 0.022) as well as in patients with >1 Giemsa-positive tumor cells (p = 0.025). CONCLUSION: PD-1(+) and PD-L1(+) CTCs could be detected before and after front-line chemotherapy in patients with metastatic NSCLC. The presence of high PD-1(+) CTC numbers before treatment is associated with a poor patient clinical outcome.

Expression of insulin-like growth factor-1 receptor in circulating tumor cells of patients with breast cancer is associated with patient outcomes.

In patients with breast cancer, markers of aggressiveness such as dysregulation of the insulin-like growth factor receptor (IGF1R) system and E-cadherin loss are commonly observed. Reduced IGF1R expression is correlated with decreased E-cadherin levels and increased cell motility. We assessed IGF1R and E-cadherin expression in circulating tumor cells (CTCs) in patients with breast cancer. Peripheral blood mononuclear cells of early (n = 87)- and metastatic (n = 126)-stage breast cancer patients (obtained prior to adjuvant and first-line chemotherapy) were evaluated using double immunofluorescence (IF) staining for cytokeratin (CK) and IGF1R. Triple IF using CK, IGF1R, and E-cadherin antibodies was performed in selected CTC(+) patients. IGF1R(+) CTCs were more frequently observed in early disease than in metastatic disease (86% vs 68% of CTCs, P = 0.04) stage, whereas IGF1R(-) CTCs were more common in metastatic than in early disease (32% vs 14% of CTCs, P = 0.002). 100% of CTC(+) patients with early disease, compared to 79% of those with metastatic disease, harbored IGF1R(+) CTCs (P = 0.007). Patients with early disease and exclusively IGF1R(+) CTCs had longer disease-free (P = 0.02) and overall survival (P = 0.001) compared to patients with both IGF1R(+) and IGF1R(-) CTC populations. 67% of early-stage CTC(+) patients evaluated had exclusively IGF1R(+)/E-cadherin(+) CTCs, 33% also had IGF1R(-)/E-cadherin(-) CTCs, and none had exclusively IGF1R(-)/E-cadherin(-) CTCs compared to 17%, 75%, and 8% of metastatic patients, respectively (P = 0.027). Similarly, in paired samples of patients with early disease that progressed to metastatic disease, the proportion of IGF1R(+)/E-cadherin(+) CTCs was reduced and IGF1R(-)/E-cadherin(-) CTCs were increased in the metastatic stage compared to early disease stage. IGF1R(+) CTCs are commonly detected in breast cancer, and their frequency decreases in the metastatic disease stage. IGF1R(+)/E-cadherin(+) CTCs also decrease in metastatic patients. IGF1R(+) CTCs are associated with favorable outcomes in early disease stage, suggesting that IGF1R expression is correlated with reduced metastatic potential in breast cancer.

Prognostic value of circulating regulatory T cell subsets in untreated non-small cell lung cancer patients.

The role of the different circulating regulatory T-cells (Treg) subsets, as well as their correlation with clinical outcome of non-small cell lung cancer (NSCLC) patients is poorly understood. Peripheral blood from 156 stage III/IV chemotherapy-naive NSCLC patients and 31 healthy donors (HD) was analyzed with flow cytometry for the presence and functionality of CD4+ Treg subsets (naive, effector and terminal effector). Their frequencies were correlated with the clinical outcome. All CD4+ Treg subsets exhibited highly suppressive activity by TGF-ß and IL-10 production. The percentages of naive Treg were found elevated in NSCLC patients compared to HD and were associated with poor clinical outcome, whereas the percentage of terminal effector Treg was lower compared to HD and higher levels were correlated with improved clinical response. At baseline, normal levels of naive and effector Treg were associated with longer overall survival (OS) compared to high levels, while the high frequency of the terminal effector Treg was correlated with longer Progression-Free Survival and OS. It is demonstrated, for first time, that particular CD4+ Treg subtypes are elevated in NSCLC patients and their levels are associated to the clinical outcome. The blocking of their migration to the tumor site may be an effective therapeutic strategy.

Effect of First-Line Treatment on Myeloid-Derived Suppressor Cells' Subpopulations in the Peripheral Blood of Patients with Non-Small Cell Lung Cancer.

INTRODUCTION: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells of myeloid origin whose expression is induced by, among others things, vascular endothelial growth factor. We have previously identified two monocytic and one granulocytic MDSC subpopulations associated with the clinical outcome in patients with non-small cell lung cancer (NSCLC). The aim of the present study was to evaluate the effect of chemotherapy on these MDSC subpopulations. METHODS: Circulating immune cells from 46 patients with unresectable NSCLC were analyzed by flow cytometry before the initiation of chemotherapy and after three cycles. Changes in the frequencies of the MDSC subpopulations were correlated with clinical outcome. RESULTS: Chemotherapy had no uniform effect on either the number or the functionality of monocytic and granulocytic MDSCs. However, three cycles of bevacizumab-containing regimens significantly reduced the percentage of the granulocytic-MDSCs compared with non-bevacizumab-based regimens (p = 0.0086). At the time of evaluation of response, disease progression was associated with significantly higher levels of all three MDSC subpopulations compared with in patients with disease control. Ιn patients with disease progression after three cycles of chemotherapy, the percentage of CD15-positive monocytic MDSCs was significantly increased compared with baseline. CONCLUSIONS: In the peripheral blood of patients with NSCLC, bevacizumab-based chemotherapy significantly reduced the levels of granulocytic MDSCs. An increase in the levels of CD15-positive monocytic MDSCs was associated with poor response to treatment and disease progression, providing evidence of their clinical relevance in patients with NSCLC.

Distinct features of circulating microparticles and their relationship with disease activity in inflammatory bowel disease.

BACKGROUND: There is evidence that circulating microparticles (MPs) and annexin (+) platelet-derived MPs (PDMPs) are increased in inflammatory bowel disease (IBD). The aim of our study was to characterize the abundance, origin, and annexin V binding of MPs in patients with IBD and correlate them with the disease characteristics. METHODS: Case-control study of 46 IBD patients (23 Crohn's disease, 23 ulcerative colitis) and 40 matched healthy controls (HC). MPs were divided according to annexin V binding, their origin was estimated based on specific cell membrane markers in plasma samples and their number was calculated via flow cytometry. Clinical and laboratory activity indices were also analyzed. RESULTS: Annexin (-) PDMPs (P=0.0004), total (P=0.04) and annexin (+) monocyte-derived MPs (P=0.02) were increased and annexin (-) total MPs (P=0.0007) were decreased in IBD patients compared to HC. The annexin (+)/(-) ratio of all MP types were significantly elevated in IBD patients compared to HC (P<0.003). IBD patients with active disease displayed elevated total and annexin (+) total MPs, total, annexin (+) and (-) PDMPs compared with those in remission (P<0.05). Annexin (-) PDMPs were considerably increased in IBD patients with active compared to those with inactive disease (P=0.0013). Total and annexin (-) PDMPs were significantly correlated with most of the disease activity indices (P<0.05). CONCLUSION: The majority of circulating MPs, their counterparts and particularly annexin (-) PDMPs are increased in active IBD patients. Annexin (+)/(-) ratio proved to be the most reliable distinctive MP index between HC and IBD patients.

A circulating subpopulation of monocytic myeloid-derived suppressor cells as an independent prognostic/predictive factor in untreated non-small lung cancer patients.

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of cells with immunosuppressive properties and might confer to worse prognosis in cancer patients. The presence of phenotypically newly described subpopulations of MDSCs and their association with the clinical outcome were investigated in non-small cell lung cancer (NSCLC) patients. The percentages and correlation between MDSCs and distinct immune cells in the peripheral blood of 110 chemotherapy-naive patients before treatment and healthy controls were investigated using flow cytometry. Two monocytic [CD14(+)CD15(-)CD11b(+)CD33(+)HLA-DR(-)Lin(-) and CD14(+)CD15(+)CD11b(+)CD33(+)HLA-DR(-)Lin(-)] and a granulocytic [CD14(-)CD15(+)CD11b(+)CD33(+)HLA-DR(-)Lin(-)] subpopulations of MDSCs were identified, expressing inducible nitric oxide synthase, and reactive oxygen species, respectively. Increased percentages of both monocytic-MDSCs' subpopulations were inversely correlated to dendritic/monocyte levels (P ≤ 0.04), while granulocytic-MDSCs were inversely correlated to CD4(+) T cells (P = 0.006). Increased percentages of monocytic-MDSCs were associated with worse response to treatment (P = 0.02) and patients with normal levels of CD14(+)CD15(+)CD11b(+)CD33(+)HLA-DR(-)Lin(-) had longer overall survival and progression free-survival compared to those with high levels (P = 0.008 and P = 0.005, resp.). Multivariate analysis revealed that the increased percentages of CD14(+)CD15(+)CD11b(+)CD33(+)HLA-DR(-)Lin(-) MDSCs were independently associated with decreased progression free-survival and overall survival. The data provide evidence that increased percentages of new monocytic-MDSCs' subpopulations in advanced NSCLC patients are associated with an unfavourable clinical outcome.

A phase II trial evaluating the clinical and immunologic response of HLA-A2(+) non-small cell lung cancer patients vaccinated with an hTERT cryptic peptide.

OBJECTIVES: The immunological and clinical responses of patients with NSCLC treated, in the context of an expanded action program, with the cryptic hTERT-targeting Vx-001 vaccine are presented. MATERIALS AND METHODS: Forty-six HLA-A*0201-positive patients with advanced NSCLC and residual (n=27) or progressive (n=19) disease following front-line treatment received two subcutaneous injections of the optimized TERT572Y peptide followed by four injections of the native TERT572 peptide, every 3 weeks. Peptide-specific immune responses were monitored by enzyme-linked immunosorbent spot assay at baseline, and after the 2nd and the 6th vaccinations. Thirty-eight HLA-A*0201-positive matched patients were used as historical controls. RESULTS: Twenty-three patients (50%) completed the vaccination protocol and 87% received at least two administrations. Twelve patients (26%) without disease progression after the 6th vaccination received boost vaccinations. Three (7%) patients achieved a partial response and 13 (28%) disease stabilization. The disease control rate was significantly higher in patients with non-squamous histology compared to those with squamous-cell histology [n=14 (45%) versus n=2 (13%); p=0.03]. The median progression-free survival (PFS) and overall survival (OS) was 3.8 (range, 0.7-99.4) and 19.8 months (range, 0.7-99.4), respectively. Patients who developed immune response had a numerically higher PFS compared to those who failed to mount any (6.7 versus 2.7 months; p=0.090). However, the median OS for the immune-responders was significantly prolonged compared to non-responders (40.0 versus 9.2 months, respectively; p=0.02). Toxicity was

Immunological responses in cancer patients after vaccination with the therapeutic telomerase-specific vaccine Vx-001.

Vx-001, an HLA-A*0201 restricted telomerase (TERT)-specific anti-tumor vaccine, is composed of the 9-mer cryptic TERT(572) peptide and its optimized variant TERT(572Y). We have previously shown that Vx-001 is non-toxic, highly immunogenic and in vaccinated NSCLC patients early specific immune response is associated with prolonged survival. The aim of the present study was to investigate the specific T-cell immune response against Vx-001. Fifty-five patients with chemo-resistant advanced solid tumors were vaccinated with TERT(572Y) (2 subcutaneous injections) followed by TERT(572) peptide (4 subcutaneous injections) every 3 weeks. Specific immune response was evaluated by IFN-γ and perforin ELISpot and intracellular cytokine staining assays. TERT-reactive T cells were detected in 27 (51%) out of 53 evaluable patients after the 2nd vaccination and in 22 (69%) out of 32 evaluable patients after the completion of 6 vaccinations. Immune responses developed irrespective of the stage of disease and disease status before vaccination. Patients with disease progression at study entry who developed a post-vaccination-induced immunological response had a significant overall survival benefit compared to the post-vaccination non-responders. The Vx-001 vaccine is a promising candidate for cancer immunotherapy since it can induce a TERT-specific T-cell immune response that is associated with prolonged survival.

Sequential administration of the native TERT572 cryptic peptide enhances the immune response initiated by its optimized variant TERT(572Y) in cancer patients.

The aim of this study was to investigate the best administration of telomerase reverse transcriptase (TERT572), an human leukocyte antigen-A*0201-restricted cryptic epitope of telomerase, and its optimized variant TERT(572Y) to elicit specific T cell immune responses in cancer patients. Forty-eight cancer patients with chemo-resistant tumors received 2 subcutaneous injections of TERT(572Y) at 2 mg followed at random by 4 subcutaneous injections of either TERT572 or TERT(572Y) peptides at 2 mg every 3 weeks. Specific immune response was evaluated by interferon-γ enzyme-linked immunosorbent spot. T cell responses after the sixth vaccination were detected more frequently (44% vs. 17%), and with higher number of peptide-specific reactive T cells (60 T cells/2 × 10(5) peripheral blood mononuclear cell vs. 10 T cells/2 × 10(5) peripheral blood mononuclear cell, P=0.04), and higher avidity in the patients who received 4 more vaccinations with the TERT572 peptide compared with patients who received only TERT(572Y) vaccinations. These results demonstrate that the best vaccination schedule involves first the administration of the optimized TERT(572Y) followed by the native TERT572 peptides in patients who are candidates for cancer immunotherapy.

Infectious mononucleosis and Epstein-Barr virus.

Epstein-Barr virus (EBV) is a gamma-herpesvirus that infects over 90% of the human population worldwide. It is usually transmitted between individuals in saliva, and establishes replicative infection within the oropharynx as well as life-long latent infection of B cells. Primary EBV infection generally occurs during early childhood and is asymptomatic. If delayed until adolescence or later, it can be associated with the clinical syndrome of infectious mononucleosis (also known as glandular fever or 'mono'), an illness characterised by fevers, pharyngitis, lymphadenopathy and malaise. EBV infection is also associated with the development of EBV-associated lymphoid or epithelial cell malignancies in a small proportion of individuals. This review focuses on primary EBV infection in individuals suffering from infectious mononucleosis. It discusses the mechanism by which EBV establishes infection within its human host and the primary immune response that it elicits. It describes the spectrum of clinical disease that can accompany primary infection and summarises studies that are leading to the development of a vaccine designed to prevent infectious mononucleosis.