Depletion of central memory CD8+ T cells might impede the antitumor therapeutic effect of Mogamulizumab.

Regulatory T (Treg) cells are important negative regulators of immune homeostasis, but in cancers they tone down the anti-tumor immune response. They are distinguished by high expression levels of the chemokine receptor CCR4, hence their targeting by the anti-CCR4 monoclonal antibody mogamulizumab holds therapeutic promise. Here we show that despite a significant reduction in peripheral effector Treg cells, clinical responses are minimal in a cohort of patients with advanced CCR4-negative solid cancer in a phase Ib study (NCT01929486). Comprehensive immune-monitoring reveals that the abundance of CCR4-expressing central memory CD8+ T cells that are known to play roles in the antitumor immune response is reduced. In long survivors, characterised by lower CCR4 expression in their central memory CD8+ T cells possessed and/or NK cells with an exhausted phenotype, cell numbers are eventually maintained. Our study thus shows that mogamulizumab doses that are currently administered to patients in clinical studies may not differentiate between targeting effector Treg cells and central memory CD8+ T cells, and dosage refinement might be necessary to avoid depletion of effector components during immune therapy.

Immunochromatography test for rapid diagnosis of Mycoplasma pneumoniae infection.

The sensitivity and specificity of a new rapid Mycoplasma pneumoniae antigen immunochromatography (IC) test, DK-MP-001, were determined using particle agglutination (PA) antibody response and loop-mediated isothermal amplification (LAMP) gene detection as the gold standard. Of 165 patients, 59 were diagnosed with M. pneumoniae infection based on a ≥fourfold rise of serum PA antibody during the course of the illness. Of the first visit swabs, 60 were positive for M. pneumoniae on LAMP, and 49 were positive for M. pneumoniae antigen on IC test. Compared with PA antibody and LAMP, the sensitivity/specificity of the IC test were 81.4% (48/59) and 99.1% (105/106); and 81.7% (49/60) and 100% (105/105), respectively. IC test detected antigen in pharyngeal swabs more sensitively than in nasal swabs for the same subjects (P < 0.05). The IC test performs well enough to be used with pharyngeal swabs at the first examination.

NY-ESO-1 Protein Cancer Vaccine With Poly-ICLC and OK-432: Rapid and Strong Induction of NY-ESO-1-specific Immune Responses by Poly-ICLC.

We conducted a clinical trial of a cancer vaccine using NY-ESO-1 protein with polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) and/or OK-432 against solid tumors. A total of 15 patients were sequentially enrolled in 4 cohorts. Patients in cohort 1 received NY-ESO-1 protein; cohort 2a received NY-ESO-1 protein+OK-432; cohort 2b received NY-ESO-1 protein+poly-ICLC; cohort 3 received NY-ESO-1 protein+OK-432+poly-ICLC with Montanide ISA-51. The endpoints of this trial were safety, NY-ESO-1 immune responses, and clinical response. Vaccine-related adverse events observed were fever and injection-site reaction (grade 1). Two patients showed stable disease after vaccination. NY-ESO-1 antibodies were observed in 4 patients at the baseline (sero-positive) and augmented in all patients after vaccination. Eleven patients showed a conversion of negative antibody responses at baseline to positive after vaccination (seroconversion). The seroconversions were observed in all 11 sero-negative patients by the fourth immunization; in particular, it was observed by the second immunization in patients with poly-ICLC, and these induced antibody responses were stronger than those in patients immunized without poly-ICLC. The number of NY-ESO-1-specific interferon (IFN)γ-producing T cells was increased in patients immunized with poly-ICLC and/or OK-432, and furthermore, the increase of IFNγ-producing CD8 T cells in patients immunized with poly-ICLC was significantly higher than that in patients without poly-ICLC. Nonspecific activations of T-cell or antigen presenting cells were not observed. Our present study showed that poly-ICLC is a promising adjuvant for cancer vaccines.

Lack of XAGE-1b and NY-ESO-1 in metastatic lymph nodes may predict the potential survival of stage III melanoma patients.

The cancer-testis antigens (CTA) are a large family of tumor-associated antigens expressed by a variety of cancer cells and primitive germ cells of the adult testis and placenta. These tumor-restricted expressing patterns suggest that CTA would be ideal targets for tumor-specific immunotherapy. XAGE-1 is a CTA that was originally identified by computer-based screening, and four transcription variants, XAGE-1a, -1b, -1c and -1d, have been characterized to date. Although the presence of XAGE-1 transcripts has been reported in various cancers, the expression of XAGE-1b in melanoma has not been fully characterized. In this study, we performed immunohistochemical staining of XAGE-1b together with NY-ESO-1, a well-known CTA, in 113 melanoma samples obtained from 84 patients and evaluated their expression in tumor cells. The effects of expression on tumor progression and patient prognosis were analyzed. Both XAGE-1b and NY-ESO-1 were expressed at high levels in lymph node metastasis and skin metastasis samples compared with the primary site (P < 0.01 in XAGE-1b and P < 0.05 in NY-ESO-1). In a subgroup analysis of 22 patients with stage III lymph node metastasis, overall survival was significantly higher in the XAGE-1b and NY-ESO-1 double-negative group than in the other groups (P < 0.05). These results suggest that lack of XAGE-1b and NY-ESO-1 expression could have a positive influence on clinical outcome in patients with melanoma.

Survival of Lung Adenocarcinoma Patients Predicted from Expression of PD-L1, Galectin-9, and XAGE1 (GAGED2a) on Tumor Cells and Tumor-Infiltrating T Cells.

The immune status of tumors varies, and this may affect the overall survival (OS) of patients. We examined tumors from 120 patients with lung adenocarcinomas with a tissue microarray for T-cell infiltration and the expression of PD-L1 and Galectin-9 (both ligands for inhibitory receptors on T cells), and cancer/testis (CT) antigen XAGE1 (GAGED2a; a tumor antigen often found on lung tumors) expression, to determine their relevance to OS. Patients defined as pStage I-IIIA could be grouped, based on the expression profiles of PD-L1, Galectin-9, and XAGE1, into cluster A, who had prolonged survival, and cluster B, who had shorter survival. The difference in survival of the clusters was confirmed separately for pStage I and pStage II-IIIA patients. Cluster A patients who also had CD4 and CD8 T-cell infiltration showed even better survival, as expected. The findings were confirmed by examining an independent validation cohort of 68 pStage I lung adenocarcinoma patients. Our data showed that PD-L1 expression was a positive indicator, whereas Galectin-9 and XAGE1 expression was negative. In vitro analyses suggested that PD-L1 expression was upregulated by IFNγ secreted from activated T cells in the tumor and Galectin-9 expression was counteracting those T cells. Thus, use of these immune markers enables the creation of a discriminant function with which to classify tumors and predict survival. Cancer Immunol Res; 4(12); 1049-60. ©2016 AACR.

Correction: Immune Responses to the Cancer Testis Antigen XAGE-1b in Non Small Cell Lung Cancer Caucasian Patients.

[This corrects the article DOI: 10.1371/journal.pone.0150623.].

Immune Responses to the Cancer Testis Antigen XAGE-1b in Non Small Cell Lung Cancer Caucasian Patients.

Immunotherapy approaches using checkpoint blockade, alone, or in combination with tumor antigen vaccination, or adoptive cell transfer, are emerging as promising approaches for the treatment of non-small cell lung cancer (NSCLC). In preparation for upcoming combined immunotherapy approaches in NSCLC, here, we have assessed spontaneous immune responses to XAGE-1b, a tumor specific antigen of the Cancer Testis Antigen group that has been previously reported to be spontaneously immunogenic in the Japanese population, in a cohort of Caucasian patients with NSCLC. We found spontaneous serological responses to XAGE-1b in 9% of the patients. Importantly, these responses were limited to, and represented 13% of, patients with adenocarcinoma tumors, the most frequent histological subtype, for which immunotherapy approaches are under development. Using a set of overlapping peptides spanning the entire XAGE-1b protein, and in support of the serological data, we detected significant XAGE-1b specific CD4+ T cell responses in all XAGE-1b seropositive patients and identified several CD4+ T cell epitopes. Altogether, our results support the relevance of the XAGE-1b antigen in Caucasians NSCLC patients with adenocarcinoma, and the implementation of future immunotherapies exploiting the high immunogenicity of the antigen in this patient population.

Evaluation of IAEA Clearance Concept for Low-level Radioactive Waste from a Radioisotope Research Institute.

UNLABELLED: The clearance of solid low-level radioactive laboratory waste (LLRW) after decay-in-storage (DIS) obtained from a research institute and thoroughly separated using the separation and classification protocols presented in this study was evaluated. METHOD: The radioisotope (RI) content of incinerated LLRW from the specified RI research group (group A); the RI content of LLRW obtained in fiscal year 2000, which contained radionuclides with half-lives of less than 164 d (LLRW2); and the RI content of the LLRW reported in group A's disposal records were compared. The LLRW2 and LLRW of group A were incinerated after 2 y of decay-in-storage and immediately after storage, respectively. RESULTS: The highest ratio of the RI of incinerated LLRW to the value in the disposal records was 2.52 for 5¹Cr. The radioactivities of radionuclides in both the LLRW2 and LLRW for ³5S, 45Ca, 5¹Cr, ¹²5I, ³²P, ³³P, and 99mTc and the incinerated ash after 1 y later of decay-in-storage were below the clearance level defined by the RS-G-1.7 of the International Basic Safety Standard without contamination by ³H and ¹4C. These remains contained very small amounts of some long-half-life radionuclides of natural origin after 7 y of decay-in-storage. CONCLUSION: This LLRW separation protocol was effective for the separation of ³H and ¹4C. LLRW2 after 2 years of DIS and its incinerated ash after one year later of DIS were below the clearance level for radioactivity and radioactivity concentration.

Phase Ia Study of FoxP3+ CD4 Treg Depletion by Infusion of a Humanized Anti-CCR4 Antibody, KW-0761, in Cancer Patients.

PURPOSE: FoxP3(+) Tregs inhibit immune responses against tumors. KW-0761 is a humanized anti-human CCR4 monoclonal antibody (mAb) that has antibody-dependent cellular cytotoxicity activity. Depletion of CCR4-expressing FoxP3(+) CD4 Tregs by KW-0761 infusion was investigated in solid cancer patients. EXPERIMENTAL DESIGN: We conducted a phase Ia clinical trial of KW-0761 infusion in 7 lung and 3 esophageal cancer patients. Toxicity, clinical efficacy, changes in lymphocyte subpopulations, including Tregs, and induction of immune responses were analyzed. RESULTS: The results showed that KW-0761 infusion in a dose range between 0.1 mg/kg and 1.0 mg/kg was safe and well tolerated. No dose-limiting toxicity was observed. Four of 10 patients showed stable disease during treatment and were long survivors. The monitoring of FoxP3(+) Tregs in the peripheral blood mononuclear cells during treatment indicated efficient depletion of those cells, even at the lowest dose of 0.1 mg/kg used. The reduction in Th 1 CD4 T cells and CD8 T cells was limited, whereas a significant reduction was observed with Th 2 and Th 17 CD4 T cells. Immune responses to cancer/testis (CT) antigens and an autoantibody response to thyroid peroxidase were observed in some patients. CONCLUSIONS: The findings showed Tregs depletion and the possible occurrence of an immune response following KW-0761 infusion. Combined use of KW-0761 to deplete FoxP3(+) Tregs with other immunotherapies, such as cancer vaccines or checkpoint inhibitors, is a promising approach to augment immune responses.

Contrasting Effects of the Cytotoxic Anticancer Drug Gemcitabine and the EGFR Tyrosine Kinase Inhibitor Gefitinib on NK Cell-Mediated Cytotoxicity via Regulation of NKG2D Ligand in Non-Small-Cell Lung Cancer Cells.

INTRODUCTION: Several cytotoxic anticancer drugs inhibit DNA replication and/or mitosis, while EGFR tyrosine kinase inhibitors inactivate EGFR signalling in cancer cell. Both types of anticancer drugs improve the overall survival of the patients with non-small-cell lung cancer (NSCLC), although tumors often become refractory to this treatment. Despite several mechanisms by which the tumors become resistant having been described the effect of these compounds on anti-tumor immunity remains largely unknown. METHODS: This study examines the effect of the cytotoxic drug Gemcitabine and the EGFR tyrosine kinase inhibitor Gefitinib on the expression of NK group 2 member D (NKG2D) ligands as well as the sensitivity of NSCLC cells to the NK-mediated lysis. RESULTS: We demonstrate that Gemcitabine treatment leads to an enhanced expression, while Gefitinib downregulated the expression of molecules that act as key ligands for the activating receptor NKG2D and promote NK cell-mediated recognition and cytolysis. Gemcitabine activated ATM and ATM- and Rad-3-related protein kinase (ATR) pathways. The Gemcitabine-induced phosphorylation of ATM as well as the upregulation of the NKG2D ligand expression could be blocked by an ATM-ATR inhibitor. In contrast, Gefitinib attenuated NKG2D ligand expression. Silencing EGFR using siRNA or addition of the PI3K inhibitor resulted in downregulation of NKG2D ligands. The observations suggest that the EGFR/PI3K pathway also regulates the expression of NKG2D ligands. Additionally, we showed that both ATM-ATR and EGFR regulate MICA/B via miR20a. CONCLUSION: In keeping with the effect on NKG2D expression, Gemcitabine enhanced NK cell-mediated cytotoxicity while Gefitinib attenuated NK cell killing in NSCLC cells.

Sensitive Multiplexed Quantitative Analysis of Autoantibodies to Cancer Antigens with Chemically S-Cationized Full-Length and Water-Soluble Denatured Proteins.

Humoral immune responses against tumor-associated antigens (TAAs) or cancer/testis antigens (CTAs) aberrantly expressed in tumor cells are frequently observed in cancer patients. Recent clinical studies have elucidated that anticancer immune responses with increased levels of anti-TAA/CTA antibodies improve cancer survival rates. Thus, these antibody levels are promising biomarkers for diagnosing the efficiency of cancer immunotherapy. Full-length antigens are favored for detecting anti-TAA/CTA antibodies because candidate antigen proteins contain multiple epitopes throughout their structures. In this study, we developed a methodology to prepare purified water-soluble and full-length antigens by using cysteine sulfhydryl group cationization (S-cationization) chemistry. S-Cationized antigens can be prepared from bacterial inclusion bodies, and they exhibit improved protein solubility but preserved antigenicity. Anti-TAA/CTA antibodies detected in cancer patients appeared to recognize linear epitopes, as well as conformational epitopes, and because the frequency of cysteine side-residues on the epitope-paratope interface was low, any adverse effects of S-cationization were virtually negligible for antibody binding. Furthermore, S-cationized antigen-immobilized Luminex beads could be successfully used in highly sensitive quantitative-multiplexed assays. Indeed, patients with a more broadly induced serum anti-TAA/CTA antibody level showed improved progression-free survival after immunotherapy. The comprehensive anti-TAA/CTA assay system, which uses S-cationized full-length and water-soluble recombinant antigens, may be a useful diagnostic tool for assessing the efficiency of cancer immunotherapy.

Detection and Tracking of NY-ESO-1-Specific CD8+ T Cells by High-Throughput T Cell Receptor ß (TCRB) Gene Rearrangements Sequencing in a Peptide-Vaccinated Patient.

Comprehensive immunological evaluation is crucial for monitoring patients undergoing antigen-specific cancer immunotherapy. The identification and quantification of T cell responses is most important for the further development of such therapies. Using well-characterized clinical samples from a high responder patient (TK-f01) in an NY-ESO-1f peptide vaccine study, we performed high-throughput T cell receptor ß-chain (TCRB) gene next generation sequencing (NGS) to monitor the frequency of NY-ESO-1-specific CD8+ T cells. We compared these results with those of conventional immunological assays, such as IFN-γ capture, tetramer binding and limiting dilution clonality assays. We sequenced human TCRB complementarity-determining region 3 (CDR3) rearrangements of two NY-ESO-1f-specific CD8+ T cell clones, 6-8L and 2F6, as well as PBMCs over the course of peptide vaccination. Clone 6-8L possessed the TCRB CDR3 gene TCRBV11-03*01 and BJ02-01*01 with amino acid sequence CASSLRGNEQFF, whereas 2F6 possessed TCRBV05-08*01 and BJ02-04*01 (CASSLVGTNIQYF). Using these two sequences as models, we evaluated the frequency of NY-ESO-1-specific CD8+ T cells in PBMCs ex vivo. The 6-8L CDR3 sequence was the second most frequent in PBMC and was present at high frequency (0.7133%) even prior to vaccination, and sustained over the course of vaccination. Despite a marked expansion of NY-ESO-1-specific CD8+ T cells detected from the first through 6th vaccination by tetramer staining and IFN-γ capture assays, as evaluated by CDR3 sequencing the frequency did not increase with increasing rounds of peptide vaccination. By clonal analysis using 12 day in vitro stimulation, the frequency of B*52:01-restricted NY-ESO-1f peptide-specific CD8+ T cells in PBMCs was estimated as only 0.0023%, far below the 0.7133% by NGS sequencing. Thus, assays requiring in vitro stimulation might be underestimating the frequency of clones with lower proliferation potential. High-throughput TCRB sequencing using NGS can potentially better estimate the actual frequency of antigen-specific T cells and thus provide more accurate patient monitoring.

Immune-mediated antitumor effect by type 2 diabetes drug, metformin.

Metformin, a prescribed drug for type 2 diabetes, has been reported to have anti-cancer effects; however, the underlying mechanism is poorly understood. Here we show that this mechanism may be immune-mediated. Metformin enabled normal but not T-cell-deficient SCID mice to reject solid tumors. In addition, it increased the number of CD8(+) tumor-infiltrating lymphocytes (TILs) and protected them from apoptosis and exhaustion characterized by decreased production of IL-2, TNFα, and IFNγ. CD8(+) TILs capable of producing multiple cytokines were mainly PD-1(-)Tim-3(+), an effector memory subset responsible for tumor rejection. Combined use of metformin and cancer vaccine improved CD8(+) TIL multifunctionality. The adoptive transfer of antigen-specific CD8(+) T cells treated with metformin concentrations as low as 10 µM showed efficient migration into tumors while maintaining multifunctionality in a manner sensitive to the AMP-activated protein kinase (AMPK) inhibitor compound C. Therefore, a direct effect of metformin on CD8(+) T cells is critical for protection against the inevitable functional exhaustion in the tumor microenvironment.

Increase in activated Treg in TIL in lung cancer and in vitro depletion of Treg by ADCC using an antihuman CCR4 mAb (KM2760).

INTRODUCTION: Tregs infiltrate tumors and inhibit immune responses against them. METHODS: We investigated subpopulations of Foxp3 CD4 T cells previously defined by Miyara et al. (Immunity 30, 899-911, 2009) in peripheral blood mononuclear cells (PBMCs) and tumor infiltrating lymphocytes (TILs) in lung cancer. We also showed that Tregs in healthy donors that express CCR4 could be efficiently eliminated in vitro by cotreatment with antihuman (h) CCR4 mAb (KM2760) and NK cells. RESULTS: In lung cancer, the number of activated/effector Tregs and non-Tregs, but not resting/naive Tregs, was increased in TILs compared with the number of those cells in PBMCs. The non-Treg population contained Th2 and Th17. CCR4 expression on activated/effector Tregs and non-Tregs in TILs was down-regulated compared with that on those cells in PBMCs. Chemokinetic migration of CD25 CD4 T cells containing the Treg population sorted from the PBMCs of healthy donors to CCL22/MDC was abrogated by pretreatment with anti-hCCR4 mAb (KM2760). The inhibitory activity of CD25 CD127 CD4 Tregs on the proliferative response of CD4 and CD8 T cells stimulated with anti-CD3/CD28 coated beads was abrogated by adding an anti-hCCR4 mAb (KM2760) and CD56 NK cells to the culture. CONCLUSIONS: The findings suggested the CCR4 on activated/effector Tregs and non-Tregs was functionally involved in the chemokinetic migration and accumulation of those cells to the tumor site. In vitro findings of efficient elimination of Tregs may give the basis for implementation of a clinical trial to investigate Treg depletion by administration of an anti-hCCR4 mAb to solid cancer patients.

Antitumor immunity by magnetic nanoparticle-mediated hyperthermia.

Magnetic nanoparticle-mediated hyperthermia (MNHT) generates heat to a local tumor tissue of above 43°C without damaging surrounding normal tissues. By applying MNHT, a significant amount of heat-shock proteins is expressed within and around the tumor tissues, inducing tumor-specific immune responses. In vivo experiments have indicated that MNHT can induce the regression of not only a local tumor tissue exposed to heat, but also distant metastatic tumors unexposed to heat. In this article, we introduce recent progress in the application of MNHT for antitumor treatments and summarize the mechanisms and processes of its biological effects during antitumor induction by MNHT. Several clinical trials have been conducted indicating that the MNHT system may add a promising and novel approach to antitumor therapy.

Hepatitis C virus-specific T-cell response correlates with hepatitis activity and donor IL28B genotype early after liver transplantation.

It is not known how the immune system targets hepatitis C virus (HCV)-infected HLA-mismatched hepatocytes under immune-suppressed conditions after orthotopic liver transplantation (OLT). In addition, the relationship between the HCV-specific immune response and IL28B variants as predictors of HCV clearance has not been well-characterized. We determined the IL28B polymorphisms for 57 post-OLT HCV carriers, and we assessed the HCV-specific immune responses by measuring the peripheral blood mononuclear cell-derived HCV-specific interferon-gamma (IFN-γ) response using an enzyme-linked immunospot assay. At 1-3 years after OLT, patients with no active hepatitis showed higher total spots on the immunospot assay. At＞3 years after OLT, patients with resolved HCV showed higher levels of core, NS3, NS5A, and total spots compared to the chronic hepatitis patients. The IL28B major genotype in the donors correlated with higher spot counts for NS5A and NS5B proteins at 1-3 years after OLT. In the post-OLT setting, the HCV-specific immune response could be strongly induced in patients with no active hepatitis with an IL28B major donor or sustained virological response. Strong immune responses in the patients with no active hepatitis could only be maintained for 3 years and diminished later. It may be beneficial to administer IFN treatment starting 3 years after OLT, to induce the maximum immunological effect.

Prolongation of overall survival in advanced lung adenocarcinoma patients with the XAGE1 (GAGED2a) antibody.

PURPOSE: The cancer/testis antigen XAGE1 (GAGED2a) is expressed in approximately 40% of advanced lung adenocarcinomas. We investigated the clinical relevance of the XAGE1 (GAGED2a) immune responses in patients with advanced lung adenocarcinoma. EXPERIMENTAL DESIGN: The XAGE1 (GAGED2a) antigen expression and EGFR mutation were determined with tumor tissues. The XAGE1 (GAGED2a) antibody and T-cell immune responses, as well as immune cell phenotypes, were analyzed with blood samples. Patients with EGFR wild-type (EGFRwt) tumors were treated with conventional platinum-based doublet chemotherapy and patients with EGFR-mutated (EGFRmt) tumors were treated with EGFR-TKI and conventional chemotherapy. The overall survival (OS) rates of the antibody-positive and -negative patients were investigated. RESULTS: The results showed that the OS of antibody-positive patients was prolonged significantly compared with that of antibody-negative patients with either XAGE1 (GAGED2a) antigen-positive EGFRwt (31.5 vs. 15.6 months, P = 0.05) or EGFRmt (34.7 vs. 11.1 months, P = 0.001) tumors. Multivariate analysis showed that the presence of the XAGE1 (GAGED2a) antibody was a strong predictor for prolonged OS in patients with XAGE1 (GAGED2a) antigen-positive tumors and in patients with either EGFRwt or EGFRmt tumors. On the other hand, XAGE1 (GAGED2a) antigen expression was a worse predictor in patients with EGFRmt tumors. Phenotypic and functional analyses of T cells indicated immune activation in the antibody-positive patients. CONCLUSIONS: The findings suggest that production of the XAGE1 (GAGED2a) antibody predicts good prognosis for patients with lung adenocarcinoma as an immune biomarker and the protective effect of this naturally occurring immune response supports the concept of immunotherapy.

Frequency of regulatory T-cell and hepatitis C viral antigen-specific immune response in recurrent hepatitis C after liver transplantation.

INTRODUCTION: Regulatory T (Treg) and type 1 regulatory T (Tr1) cells facilitate hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT). However, their frequencies and effects on HCV-specific immune responses have not been well investigated. METHODS: We determined Treg and Tr1 frequencies in OLT patients with hepatitis C and assessed their associations with HCV-specific T cell responses. These patients comprised the following groups: an early post-transplantation group (n=14); an OLT-chronic active hepatitis C group (n=14) with active hepatitis C (alanine aminotransferase of>upper limit of normal/positive for HCV-RNA); an OLT-persistently normal alanine aminotransferase group (n=12) without active hepatitis C (not interferon/positive for HCV-RNA); and an OLT-sustained viral response group (n=6) with sustained viral responses using interferon treatment (negative for HCV-RNA). The frequencies of HCV-specific CD4+ T cells that secreted interferon-γ were determined by enzyme-linked immunosorbent spot assay (except for the OLT early group). RESULTS: Treg and Tr1 frequencies were low during the early post-transplantation period. OLT patients with sustained viral responses had lower Treg frequencies than those with chronic hepatitis C, whereas Tr1 frequencies were significantly reduced in OLT patients with persistently normal alanine aminotransferase levels compared to those with chronic hepatitis C (p<0.05). Treg frequencies positively correlated with HCV NS3 antigen-specific interferon-γ responses, which corresponded to HCV clearance. CONCLUSIONS: Increased Treg frequencies and reduced HCV-NS3 antigen-specific responses recovered after viral eradication in post-OLT chronic hepatitis C patients. Reduced Tr1 frequencies were associated with hepatitis activity control, which may facilitate controlling chronic hepatitis C in patients after OLT.

Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.2 KE Picibanil OK-432 and 1.25 mL Montanide ISA-51. The primary endpoints of this study were safety and NY-ESO-1 immune responses. Five to 18 injections of the NY-ESO-1 OLP vaccine were well tolerated. Vaccine-related adverse events observed were fever and injection site reaction (grade 1 and 2). Two patients showed stable disease after vaccination. An NY-ESO-1-specific humoral immune response was observed in all patients and an antibody against peptide #3 (121-150) was detected firstly and strongly after vaccination. NY-ESO-1 CD4 and CD8 T-cell responses were elicited in these patients and their epitopes were identified. Using a multifunctional cytokine assay, the number of single or double cytokine-producing cells was increased in NY-ESO-1-specific CD4 and CD8 T cells after vaccination. Multiple cytokine-producing cells were observed in PD-1 (-) and PD-1 (+) CD4 T cells. In conclusion, our study indicated that the NY-ESO-1 OLP vaccine mixed with Picibanil OK-432 and Montanide ISA-51 was well tolerated and elicited NY-ESO-1-specific humoral and CD4 and CD8 T-cell responses in immunized patients.

Production of NY-ESO-1 peptide/DRB1*08:03 tetramers and ex vivo detection of CD4 T-cell responses in vaccinated cancer patients.

We established CD4 T-cell clones, Mz-1B7, and Ue-21, which recognized the NY-ESO-1 121-138 peptide from peripheral blood mononuclear cells (PBMCs) of an esophageal cancer patient, E-2, immunized with an NY-ESO-1 protein and determined the NY-ESO-1 minimal epitopes. Minimal peptides recognized by Mz-1B7 and Ue-21 were NY-ESO-1 125-134 and 124-134, respectively, both in restriction to DRB1*08:03. Using a longer peptide, 122-135, and five other related peptides, including either of the minimal epitopes recognized by the CD4 T-cell clones, we investigated the free peptide/DR recognition on autologous EBV-B cells as APC and peptide/DR tetramer binding. The results showed a discrepancy between them. The tetramers with several peptides recognized by either Mz-1B7 or the Ue-21 CD4 T-cell clone did not bind to the respective clone. On the other hand, unexpected binding of the tetramer with the peptide not recognized by CD4 T-cells was observed. The clone Mz-1B7 did not recognize the free peptide 122-135 on APC, but the peptide 122-135/DRB1*08:03 tetramer bound to the TCR on those cells. The failure of tetramer production and the unexpected tetramer binding could be due to a subtly modified structure of the peptide/DR tetramer from the structure of the free peptide/DR molecule. We also demonstrated that the NY-ESO-1 123-135/DRB1*08:03 tetramer detected ex vivo CD4 T-cell responses in PBMCs from patients after NY-ESO-1 vaccination in immunomonitoring.