OBJECTIVETo observe the regulating effect of hepatitis C virus (HCV) envelop (E) 2 gene immunization-induced immune responses by adenovirus mediated interleukin 12 (IL-12).

METHODSHCV E2 protein was expressed and purified from NIH 3T3 and then used as an antigen to detect antibodies against HCV E2. With 51Cr release, SP2/0 expressing HCV E2 was used as target cell to detect specific cytotoxic T lymphocytes (CTL) response; adenovirus recombined IL-12 was propagated by 293 cell. HCV E2 recombinant and adenovirus recombined IL-12 were injected into the quadriceps femoris muscles and abdominal cavities of 6-8 weeks old BALB/C mice. Sera were collected at 2, 3, and 4 weeks and detected for antibodies for E2. Spleen cells isolated at 4 weeks were analyzed for specific CTL response.

RESULTSIt was found that expression of IL-12 at an undetectable level did enhance HCV E2 gene immunization-induced CTL activity and there was no effect on its hormonal immune response.

CONCLUSIONUsing adenovirus to express interleukin 12 was helpful for regulation of HCV E2 gene immunization-induced immune response. Combined HCV E2 and IL-12 can render a strong anti-HCV CTL activity and may be of use in the development of HCV gene vaccine in the future.

Adenoviridae ; physiology ; Interleukin-12 ; biosynthesis ; genetics ; T-Lymphocytes, Cytotoxic ; immunology ; Viral Envelope Proteins ; genetics ; immunology

DNA vaccination that can induce both cellular and humoral immune response has become an attractive immunization strategy against cancer and infectious disease. Elucidation of the precise mechanisms of immune priming will be important in the development of effective DNA vaccines. In this review, we illustrate possible mechanisms in priming cytotoxic T cell response involving the intracellular degradation, processing and presentation of encoded antigen. We also discuss the roles of costimulatory molecules expressed on antigen-presenting cells (APCs) in inducing optimal CTL activity. Hence, a rational strategy for increasing DNA potency would be to facilitate these pathways. Additionally, we focus on recent strategies including rapid degradation of ubiquitin-antigen fusion proteins, direct targeting to APCs for increased DNA uptake, direct routing an antigen into the MHC class I and II processing and presentation pathways, and increasing the immunogenicity of encoded antigen. All of these approaches have resulted in increased potency of DNA vaccines.
Animals ; Antigen Presentation ; Antigen-Presenting Cells ; immunology ; Lysosomes ; immunology ; Mice ; T-Lymphocytes, Cytotoxic ; immunology ; Ubiquitin ; physiology ; Vaccines, DNA ; genetics ; immunology

Animals ; Epitopes, T-Lymphocyte ; immunology ; Equine Infectious Anemia ; immunology ; virology ; Horses ; Infectious Anemia Virus, Equine ; immunology ; physiology ; T-Lymphocytes, Cytotoxic ; immunology ; physiology

OBJECTIVETo study the cytotoxic activity against tumor cells and cytokines production of spleen cells induced in vitro by murine 4-1BBL gene transfected Hepa1-6.

METHODSThe eukaryotic expression vector pCDNA3.1(+)-m4-1BBL was transfected into murine hepatocellular carcinoma cell line Hepa1-6 by Liposomes. Then the transfected cells were selected in medium containing G418 (400 - 800 micro g/ml) and termed as Hepa1-6-m4-1BBL. The TCV-m4-1BBL was obtained by treating them with mitomycin (MMC). Cocultivation TCV with syngeneic murine spleen cells, then the lymphocytes were tested for cytotoxic activity against Hepa1-6-wt cells and the supernatants were harvested for detecting the cytokines (IL-2, TNF-alpha and GM-CSF).

RESULTSHepa1-6-m4-1BBL cells expressed 4-1BBL protein with highest cell surface level. The 4-1BBL mRNA could still be detected in the cells when cultured 48 h after treated with MMC (80 mg/L). Comparing with TCV-Hepa1-6, the tumor cell vaccine derived from Hepa1-6-m4-1BBL (TCV-m4-1BBL) could induce a more efficient cytotoxic activity of syngeneic murine lymphocyte against its parental tumor cell Hepa1-6 (P < 0.05), but not against non-parental tumor cell H22 and NIH3T3. Higher levels of IL-2, TNF-alpha and GM-CSF were released by the splencytes after stimulated by TCV-m4-1BBL.

CONCLUSIONSThese results suggest the expression of m4-1BBL by tumor cells is effective in inducing antitumor immune responses.

4-1BB Ligand ; Animals ; Cancer Vaccines ; immunology ; Female ; In Vitro Techniques ; Liver Neoplasms, Experimental ; immunology ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Necrosis Factors ; genetics ; physiology

OBJECTIVETo characterize HIV-1 specific CTL responses to regulatory proteins Tat and Rev in HIV-B'/C virus-infected ART-naive individuals.

METHODSHIV-1-specific CTL responses were analyzed by IFN-gamma ELISPOT assay using overlapping peptides spanning the consensus sequences of HIV-1 clade C Tat and Rev proteins. Statistical analysis and graphical presentation were performed using SIGMAPLOT 10.0 and SIGMASTAT 3.5. For samples with a positive response, the magnitude of CTL responses was compared between HIV-1 C proteins by Wilcoxon rank sum test, and the significance threshold was P<0.05.

RESULTSTat and Rev were frequently recognized, with 23% and 52% of the tested individuals having detectable responses to these proteins, respectively. Several immunodominant regions were detected in Rev. No significant correlation was observed between the magnitude and breadth of CTL responses to regulatory proteins and the control of virus replication in this study.

CONCLUSIONTat and Rev can serve as targets for HIV-1-specific CTL, and several immunodominant regions are detectable in Rev. Further characterization of epitopes and their role in virus control may shed light on pathogenesis of HIV-1 natural infection and also be useful for the design and testing of candidate vaccines.

Amino Acid Sequence ; Gene Products, rev ; immunology ; Gene Products, tat ; immunology ; HIV ; physiology ; HIV Infections ; immunology ; Humans ; Molecular Sequence Data ; T-Lymphocytes, Cytotoxic ; immunology ; Virus Replication

Human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTLs) play a critical role in the control of HIV-1 infection and replication. HIV-1 evades CTL mediated pressure through viral escape mutations within targeted CTLs epitopes or flanking regions, but this process is usually associated with a viral fitness cost. The mutated epitopes may weaken the level of the original CTL responses, however, the immune system holds potential to mount denovo responses towards those newly emerged epitopes. This article briefly summarizes recent research progress regarding the competition between HIV-1's escape mutations and host CTL responses.
Animals ; HIV Infections ; genetics ; immunology ; HIV-1 ; genetics ; immunology ; physiology ; Histocompatibility Antigens Class I ; genetics ; immunology ; Humans ; Mutation ; T-Lymphocytes, Cytotoxic ; immunology ; virology

As a member of the HSP90 family, heat shock protein (HSP) Gp96 is one of the most abundant proteins in the endoplasmic reticulum (ER), which displayed important molecular chaperones function in cells. Gp96 can stimulate the production of cytokines by activating the antigen presentation cells (such as dendritic cell, et al) in innate immunity. It is capable of eliciting an antigen-specific cytotoxic T lymphocyte (CTL) immune response to eliminate pathogens and tumors by facilitating antigen cross-presentation in adaptive immunity. Gp96 is also an ideal adjuvant in many recent researches. Here, we review the progress that addresses the role of biological characteristics, immunogenic mechanism that may be involved in the induction of anti-infection immune response and antitumor immunity, which may guide the new vaccine strategies with the knowledge of Gp96-antigen complexes.
Adjuvants, Immunologic ; genetics ; metabolism ; Antigen-Presenting Cells ; physiology ; Communicable Diseases ; immunology ; Dendritic Cells ; immunology ; Endoplasmic Reticulum ; immunology ; Humans ; Membrane Glycoproteins ; immunology ; Neoplasms ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

BACKGROUND/AIMS: This study aimed to detect the expression of natural killer (NK) cell receptor natural killer group 2D (NKG2D) in the peripheral blood of patients with primary hepatocellular carcinoma and to discuss the correlation between NK cell cytotoxicity and liver function. METHODS: The number of NK cells and the expression of NK cell receptor NKG2D in peripheral blood were determined by flow cytometry in patients with primary hepatocellular carcinoma, hepatitis B cirrhosis, chronic hepatitis B, and healthy controls. RESULTS: When compared with patients in the healthy and the chronic hepatitis B groups, the primary hepatocellular carcinoma group showed significant decreases in all parameters, including the cytotoxicity of NK cells on K562 cells, expression rate of NKG2D in NK cells, number of NKG2D+ NK cells, expression level of NKG2D, and number of NK cells (p<0.05). The activity of NK cells showed a positive correlation, whereas the Child-Pugh scores in the primary hepatocellular carcinoma and the hepatitis B cirrhosis groups showed a negative correlation with all parameters detected above. CONCLUSIONS: The decrease of NK cell activity in patients with primary hepatocellular carcinoma is closely related to their lower expression of NKG2D. Liver function affects the expression of NKG2D and the activity of NK cells.
Carcinoma, Hepatocellular/*physiopathology ; Case-Control Studies ; Female ; Humans ; K562 Cells ; Killer Cells, Natural/*physiology ; Liver Neoplasms/*physiopathology ; Lymphocyte Subsets/physiology ; Lymphopenia/physiopathology ; Male ; Middle Aged ; NK Cell Lectin-Like Receptor Subfamily K/metabolism ; T-Lymphocytes, Cytotoxic/physiology

Untreated human immunodeficiency virus (HIV) infections usually lead to death from AIDS, although the rate of the disease progression varies widely among individuals. The cytotoxic T lymphocyte (CTL) response, which is restricted by highly polymorphic MHC class I alleles, plays a central role in controlling HIV replication. It is now recognized that the antiviral efficacy of CTLs at the single cell level is dependent on their antigen specificity and is important in determining the quality of host response to viruses so that the individual will remain asymptomatic. However, because of the extreme mutational plasticity of HIV, HIV-specific CTL responses are continuously and dynamically changing. In order to rationally design an effective vaccine, the questions as to what constitutes an effective antiviral CTL response and what characterizes a potent antigenic peptide to induce such responses are becoming highlighted as needing to be answered.
Animals ; Antigens, Viral ; immunology ; metabolism ; Epitopes, T-Lymphocyte ; Evolution, Molecular ; Genetic Variation ; HIV Infections ; immunology ; virology ; HIV-1 ; genetics ; pathogenicity ; physiology ; Host-Pathogen Interactions ; Humans ; Immunodominant Epitopes ; T-Lymphocytes, Cytotoxic ; immunology ; metabolism ; virology ; Virus Replication

Antigens, CD ; physiology ; B7-2 Antigen ; Carcinoma, Hepatocellular ; immunology ; Cell Line, Tumor ; Humans ; Interferon-gamma ; biosynthesis ; Interleukin-4 ; biosynthesis ; Liver Neoplasms ; immunology ; Membrane Glycoproteins ; physiology ; T-Lymphocytes, Cytotoxic ; immunology