Natural and activated cytotoxic lymphocytes reactivity to human hepatocellular carcinoma cell lines in hepatocellular carcinoma patients

Encapsulation mechanisms and structural studies of GRM2 bacterial microcompartment particles

Bacterial microcompartments (BMCs) are prokaryotic organelles consisting of a protein shell and an encapsulated enzymatic core. BMCs are involved in several biochemical processes, such as choline, glycerol and ethanolamine degradation and carbon fixation. Since non-native enzymes can also be encapsulated in BMCs, an improved understanding of BMC shell assembly and encapsulation processes could be useful for synthetic biology applications. Here we report the isolation and recombinant expression of BMC structural genes from the Klebsiella pneumoniae GRM2 locus, the investigation of mechanisms behind encapsulation of the core enzymes, and the characterization of shell particles by cryo-EM. We conclude that the enzymatic core is encapsulated in a hierarchical manner and that the CutC choline lyase may play a secondary role as an adaptor protein. We also present a cryo-EM structure of a pT = 4 quasi-symmetric icosahedral shell particle at 3.3 Å resolution, and demonstrate variability among the minor shell forms.

Immunophenotypes and Cytotoxic Functions of Lymphocytes in Patients with Hepatocellular Carcinoma

Aims and background

Hepatocellular carcinoma (HCC) is one of the most common cancers in Asia. Immunological mechanisms are thought to play an important role in the control of tumor progression. The immune responses in HCC patients are poorly understood. In the present study, the proliferation and cytotoxic functions of lymphocytes from tumor tissues and peripheral blood of HCC patients were analysed. Simultaneously, the microcultures were phenotyped in order to determine the involvement of different lymphocyte subsets in mediating the cytotoxic function.

Methods

The frequencies of proliferating and cytotoxic lymphocytes from three tumor tissues and peripheral blood from ten HCC patients and nine healthy individuals were assessed by limiting dilution microculture analysis. These microcultures were phenotyped by single and dual color flow cytometry using monoclonal antibodies specific for CD4, CD8, CD56 and HLA-DR markers.

Results

The precursor frequencies of both proliferating and cytotoxic lymphocytes were found to be comparable in the peripheral blood of HCC patients and healthy individuals. Compared to peripheral blood, a marked reduction in the precursor frequencies of proliferating and cytotoxic lymphocytes was observed in the tumor tissues of HCC patients. In the tumor tissues, a significantly higher frequency of cytotoxic T cells compared to natural killer cells was observed. Dual color flow cytometric analysis revealed increased percentages of CD8+ HLA-DR+ lymphocytes compared to CD4+ HLA-DR+ cells in the tumor tissues.

Conclusions

Our results suggest that depressed immune responses at the tumor site might be responsible for the escape of tumor cells from the immune surveillance of the host.

Immunobiology of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a tumor of increasing incidence and high mortality worldwide. Diagnosis of HCC is often difficult, especially at early stages of disease. Additionally, current treatment options are limited. HCC usually develops in an environment of chronic liver disease. The immune system has an important role in shaping this environment, especially in chronic viral hepatitis, the leading cause of HCC. However, the immune system also plays a role in natural immunity against HCC although this is apparently not sufficient to control the majority of tumors. This failure in tumor control is due to multiple immunomodulatory mechanisms employed by HCC to subvert the immune system. In this review, we will summarize the current knowledge about the role of the immune system in hepatocarcinogenesis. Additionally, we will describe the mechanisms used by the immune system to control established lesions and the reasons why these immune responses apparently fail so often. Finally, possible implications for the design of novel immunotherapeutic strategies will be discussed.

Preliminary results of an individually tailored psychosocial intervention for patients with advanced hepatobiliary carcinoma

BACKGROUND

A plethora of research now exists documenting the benefits of psychosocial interventions for cancer patients; however, no studies have been conducted with people diagnosed with hepatobiliary carcinoma.

METHODS

A total of 28 patients agreed to participate in the study in which 14 patients were randomized to the intervention arm of the study and 14 patients to an attention-standard of care arm. Evaluation of the benefits of the intervention was performed using the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep), the Center for Epidemiological Studies-Depression, the State Trait Anxiety Index (STAI) to assess anxiety, peripheral blood leukocytes to measure immune system modulation, and survival.

RESULTS

Results indicate that patients who were randomly assigned to the intervention arm of the study reported clinically, but not statistically, significant improvements on symptoms of depression and anxiety, disease-related symptoms and treatment side effects, health-related quality of life (HRQL), and modest improvements in peripheral blood leukocytes and survival when compared with the standard of care group.

CONCLUSIONS

The findings of this study suggest that the individually tailored intervention was feasible and preliminary data suggested that the intervention may improve patients' HRQL, mood, and had modest improvements in immune system functioning and survival. Further research is needed with a larger sample size to test the statistical significance and generalizability of the individually tailored intervention.

Natural killing activities in chronic liver diseases and hepatocellular carcinoma

Previously we proposed a new analysis of natural killing activity, for comparison, employing an individual effector/target cell ratio according to the peripheral number of effector cells. Using this analysis, we studied natural killing activities in chronic liver diseases and hepatocellular carcinoma (HCC). The activity in chronic persistent hepatitis remained nearly at the level of the nonactivated state, but that was significantly elevated in chronic active hepatitis. The activity in liver cirrhosis (LC) of Child's A or B grade was at the level of a nonactivated or reduced-activity state, while LC patients with impaired general conditions showed significantly elevated activities. In HCC, each of which was accompanied by LC in our cases, the activity appeared to be associated with the progression of HCC. Thus, natural killing activity showed a close relationship with the condition of chronic liver diseases.

Effect of arginase on splenic killer cell activity in patients with gastric cancer

Arginase has been detected in high levels in gastric cancer tissues. The effect of arginase on the activities of splenic natural killer (NK) cell, phytohemagglutinin activated killer (PAK) cell, and interleukin-2 activated killer (LAK) cell in patients with gastric cancer (N = 12) was evaluated in vitro. These activities in patients (N = 10) with trauma and benign lesions were used as control. The splenic NK and PAK cell activities in patients with gastric cancer were significantly lower than in the controls (P < 0.05), whereas LAK cell activity did not have significant difference. Arginase inhibited all splenic killer cell activities to a similar degree between patients with gastric cancer and the controls. The inhibition was dose-related. These data suggest that arginase may play a positive role in the spread of gastric cancer cells. However, LAK may be a potential approach of immunoadoptive therapy in the future.