1liver-infiltrating lymphocytes 4 of patients with chronic hepa-A cytotoxic T lymphocyte (CTL) response to the hepatitis C, the role of CTL responses in HCV infection is untitis C virus (HCV) nucleoprotein residues 88-96 that are known. HCV infection frequently persists and is implicated the minimal and optimal epitope for human leukocyte in the development of chronic hepatitis, cirrhosis, and hepatoantigen (HLA) B44-restricted CTLs was assessed in 27 cellular carcinoma. 5 Posttransfusion HCV infection has de-HLA B44-positive patients with chronic HCV infection.creased substantially after introduction of an anti-HCV assay Serum HCV RNA concentration and the amino acid sefor blood screening, but community-acquired HCV infection quence of the residues 81-100 were also determined.still occurs. Interferon therapy is effective in less than 50% Three patients were infected with HCV with uncommon of patients with chronic hepatitis C. 6 Understanding the role amino acid substitutions within the epitope. One was of CTL responses in HCV infection may contribute to the infected with HCV with an amino acid substitution in development of strategies for the prevention of HCV infection the flanking residues of the epitope. To stimulate CTLs and the elimination of HCV from infected individuals. in the peripheral blood, 9-mer peptides that correRecently, we showed the presence of CTLs that recognize sponded to the residues 88-96 of the individual patients endogenously synthesized HCV antigen in the peripheral were synthesized and used. Seven of the 27 patients demblood of some patients with HCV infection by stimulation onstrated a CTL response to the residues 88-96 with of peripheral blood lymphocytes (PBLs) with HCV synthetic specific cytotoxic activities higher than 20%. The CTL peptides.3 activities were significantly higher in patients with a The CTLs recognized an epitope in the HCV nucleoprotein low titer of serum HCV RNA than in those with a high residues 81-100 in association with human leukocyte antigen titer of serum HCV RNA (P Å .0006). Some of the patients (HLA) B44. The minimal and optimal epitope was further dethat demonstrated a CTL response to the residues 88-fined to be the residues 88-96. 7 The 9-mer peptide of the resi-96 also demonstrated a CTL response to a newly identidues 88-96 was recognized by and stimulated the CTLs more fied HLA B44-restricted CTL epitope or a known HLA efficiently than the 20-mer peptide of the residues 81-100. A11-restricted CTL epitope or both. No apparent associa-In a characteristic antiviral CTL response in vivo, immunotion was observed between the CTL response and the dominant CTLs recognize only one or a few multiple immunostage of disease, or between the CTL response and the genic CTL epitopes in the antigen, 8,9 but as many as five grade of necroinflammatory activity. The results suggest different epitopes for HCV-specific CTLs were detected in a that the HLA B44-restricted CTLs together with other single individual. 10 CTL activities to HCV could not be dem-HCV-specific CTLs ...

Our results suggest that strong TAA-specific CD8(+) T-cell responses suppress the recurrence of HCC. Immunotherapy to induce TAA-specific cytotoxic T lymphocytes by means such as the use of peptide vaccines should be considered for clinical application in patients with HCC after local therapy.

IFN-α gene therapy has been successfully applied in several tumor models. Our studies involving the murine colorectal adenocarcinoma cell line MC38 confirm that IFN-α transduction of a poorly immunogenic tumor cell reduces tumorigenicity and leads to long-lasting tumor immunity. To investigate the effect of IFN-α transduction on the development of antitumor immune responses, we restimulated splenocytes from MC38-immune mice in vitro. Detection of MC38-specific cytotoxicity was markedly enhanced when murine IFN-α2-transduced MC38 (MC38-IFNα) or CD80-transduced MC38 (MC38-CD80) was used for restimulation compared with wild type (MC38-WT) or neomycin resistance gene-transduced MC38 (MC38-Neo) cells. MC38-specific CD8+ CTL line and clone were established from splenocytes of mouse immunized with MC38-IFNα. Stimulation with MC38-IFNα as well as MC38-CD80 enhanced the proliferation of MC38-specific CTLs in vitro much more effectively than stimulation with WT or MC38-Neo (p < 0.05). Coincubation of MC38-specific CTLs with MC38-IFNα or MC38-CD80 resulted in significantly less DNA fragmentation (8.0% and 12.8%, respectively) compared with coincubation of the CTLs with MC38-WT (43.5%; p < 0.001) or MC38-Neo cells (38.1%; p < 0.003). These results suggest that prevention of apoptotic cell death in tumor-specific CTLs may be one mechanism by which IFN-α-expressing tumor cells can promote the generation of antitumor immunity. The effect of IFN-α on CTLs appears to be similar to that of CD80, which also prevents apoptotic cell death after stimulation of T lymphocytes.

Infection with hepatitis C virus (HCV) is associated with lymphoproliferative disorders, represented by essential mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma, but the pathogenic mechanism remains obscure. HCV may infect B cells or interact with their cell surface receptors, and induce lymphoproliferation. The influence of HCV infection of B cells on the development of lymphoproliferative disorders was evaluated in 75 patients with persistent HCV infection. HCV infection was more prevalent (63% vs. 16%, 14%, or 17% P < 0.05 for each), and HCV RNA levels were higher (3.35 +/- 3.85 vs. 1.75 +/- 2.52, 2.15 +/- 2.94 or 2.10 +/- 2.90 log copies/100 ng, P < 0.01 for each) in B cells than CD4(+), CD8(+) T cells or other cells. Negative-strand HCV RNA, as a marker of viral replication, was detected in B cells from four of the 75 (5%) patients. Markers for lymphoproliferative disorders were more frequent in the 50 patients with chronic hepatitis C than the 32 with chronic hepatitis B, including cryoglobulinemia (26% vs. 0%, P < 0.001), low CH(50) levels (48% vs. 3%, P = 0.012), and the clonality of B cells (12% vs. 0%, P < 0.01). By multivariate analysis, HCV RNA in B cells was an independent factor associated with the presence of at least one marker for lymphoproliferation (odds ratio: 1.98 [95% confidence interval: 1.36-7.24], P = 0.027). Based on the results obtained, the infection of B cells with HCV would play an important role in the development of lymphoproliferative disorders.

The “Guideline on the Use of New Anticancer Drugs for the Treatment of Hepatocellular Carcinoma” was prepared by the Study Group on New Liver Cancer Therapies established by the “Research Project on Emergency Measures to Overcome Hepatitis” under the auspices of the Health and Labour Sciences Research Grant. The Guideline brings together data collected by the Study Group on the use and incidence of adverse events in 264 patients with advanced hepatocellular carcinoma (HCC) treated using sorafenib and in 535 patients with advanced HCC treated using miriplatin at 16 participating institutions up until 22 December 2010, as well as referring to the published studies, academic presentations, and reports from the private sector. The aim of this Guideline is to facilitate understanding and current thinking regarding the proper usage of new anticancer drugs towards actual use in therapy. In terms of the format, the Guideline presents “clinical questions” on issues pertaining to medical care, makes “recommendations” on diagnosis and treatment in response to each of these clinical questions, and provides a rationale for these recommendations in the form of “scientific statements”.

An epitope that acted as a weak agonist in the cytotoxicity assay was identified as part of the capsid protein of a hepatitis C virus (HCV) variant. In a low concentration, the variant epitope also had a weak antagonistic effect. When a minute amount of this variant epitope was added to the culture for induction, it selectively attenuated the expansion of major cytotoxic T cell populations and drastically reduced the cytotoxic responses against the wild-type epitope. Thus, antagonism to induction suppressed immune responses against both the wild type and the variant, thereby helping the persistence of not only variant itself but also the wild-type HCV. Because this variant was a weak agonist, most cytotoxic T cells induced with the wild-type epitope were cross-reactive with the variant and susceptible to the antagonism to induction. Only the T cells which were not cross-reactive with the variant and not susceptible to the antagonism survived the antagonism in induction. This implied that the specificity of the remaining immune response, if any, was directed exclusively to the wild-type epitope after the emergence of the variant. For viruses like HCV, being heterogeneous itself may contribute significantly toward persistent infection through antagonism to induction.

Intrahepatic Tregs were increased in both patients with autoimmune liver diseases and those with viral hepatitis. In autoimmune liver diseases, intrahepatic Tregs were fewer in the AIH patients than in the PBC patients.

Dendritic cells (DC) are potent antigen-presenting cells that are important for the priming of antitumor cytotoxic T cells. Recent reports suggest that DC may also have direct cytotoxic effector functions against selected tumor-cell lines by mechanisms that are dependent on dendritic cell-tumor cell contact in vitro. The authors report that ex vivo-generated murine DC induce the apoptosis of a panel of syngeneic and allogeneic murine tumors. Apoptosis of the MCA205 fibrosarcoma tumor-cell line by C57BL/6-derived DC was not mediated by Fas/FasL interactions and, in contrast to other studies, DC-tumor cell contact was not required to effect tumor-cell killing by DC. Therefore, the authors postulated that tumor-cell killing was mediated by an apoptotic factor that was secreted by DC. Even though DC did not secrete such apoptotic cytokines as interferon-alpha or tumor necrosis factor-alpha, they did secrete nitric oxide, and tumor apoptosis was partially abrogated by the nitric oxide synthase antagonist NG-monomethyl-L-arginine. Therefore, the authors' data demonstrate a novel mechanism for DC-induced tumor-cell apoptosis that does not require DC-tumor cell contact and is partially mediated by nitric oxide.