Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM To identify hepatitis C virus (HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL).METHODS Utilizing the method of computer prediction followed by a 4 h 51 Cr-release assay confirmation.RESULTS The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide 'ALAHGVFAL (core TS0-158)'.The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%,respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis.But blocking of CTL response with anti-CD8 mAb could abolish the Iysis.CONCLUSION The peptide (core 150 - 158 ) is the candidate epitope recognized by HLA-A2 restricted CTL.

In-vitro activation of cytotoxic T lymphocytes by fusion of mouse hepatocellular carcinoma cells and lymphotactin gene-modified dendritic cells

AIM: To investigate the in-vitro activation of cytotoxic T lymphocytes (CTLs) by fusion of mouse hepatocellular carcinoma (HCC) cells and lymphotactin gene-modified dendritic cells (DCs). METHODS: Lymphotactin gene modified DCs (DCLptn) were prepared by lymphotactin recombinant adenovirus transduction of mature DCs which differentiated from mouse bone marrow cells by stimulation with granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-α). DCLptn and H22 fusion was prepared using 50% PEG. Lymphotactin gene and protein expression levels were measured by RT-PCR and ELISA, respectively. Lymphotactin chemotactic responses were examined by in-vitro chemotaxis assay. In-vitro activation of CTLs by DCLptn/H22 fusion was measured by detecting CD25 expression and cytokine production after autologous T cell stimulation. Cytotoxic function of activated T lymphocytes stimulated with DCLptn/H22 cells was determined by LDH cytotoxicity assay. RESULTS: Lymphotactin gene could be efficiently transduced to DCs by adenovirus vector and showed an effective biological activity. After fusion, the hybrid DCLptn/H22 cells acquired the phenotypes of both DCLptn and H22 cells. In T cell proliferation assay, flow cytometry showed a very high CD25 expression, and cytokine release assay showed a significantly higher concentration of IFN-γ and IL-2 in DCLptn/H22 group than in DCLptn, DCLptn+H22, DC/H22 or H22 groups. Cytotoxicity assay revealed that T cells derived from DCLptn/H22 group had much higher anti-tumor activitythan those derived from DCLptn, H22, DCLptn+H22, DC/ H22 groups. CONCLUSION: Lymphotactin gene-modified dendritoma induces T-cell proliferation and strong CTL reaction against allogenic HCC cells. Immunization-engineered fusion hybrid vaccine is an attractive strategy in prevention and treatment of HCC metastases.

Frequencies and Characterization of HBV-specific Cytotoxic T Lymphocytes in Self-limited and Chronic Hepatitis B Viral Infection in China

Hepatitis B virus （HBV）-specific cytotoxic T lymphocytes （CTLs） are believed to play a major role in viral clearance and disease pathogenesis during HBV infection. To clarify the differences in host immune responses between self-limited and chronic HBV infections, we constructed three HLA-A＊0201/HBV tetramers with immunodominant epitopes of core18-27, polymerase 575-583 and envelope 335-343, and analyzed the HBV-specific CTLs in peripheral blood mononuclear cells （PBMCs） from patients infected with HBV. The frequencies and expansion ability of HBV-specific CD8＋T cells in most self-limited HBV infected individuals were higher than those in chronic HBV-infected patients. HBV-specific CD8＋T cells could be induced by in vitro peptide stimulation from chronic patients with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. In chronic infection, no significant correlation was found either between the frequencies of HBV-specific CD8^＋ T cells and the viral load, or between the frequencies and the levels of alanine transaminase. Our results suggested that the frequencies of HBV-specific CTLs are not the main determinant of immune-mediated protection in chronic HBV infection and immunotherapeutic approaches should be aimed at not only boosting a HBV-specific CD8^＋T response but also improving its function.

Procedure for preparing peptide-major histocompatibility complex tetramers for direct quantification of antigen-specific cytotoxic T lymphocytes

AIM: To establish a simplified method for generating peptide-major histocompatibility complex (MHC) class I tetramers.METHODS: cDNAs encoding the extracellular domain of human lymphocyte antigen (HLA)-A*0201 heavy chain (A2) and β2-microglobulin (β2m) from total RNA extracted from leukocytes of HLA-A2+ donors were doned into separate expression vectors by reverse transcription-polymerase chain reaction. The recombinant A2 and β2m proteins were expressed in Escherichia coli strain BL21(DE3) and recovered from the inclusion body fraction. Soluble A2 proteins loaded with specific antigen peptides were refolded by dilution from the heavy chain in the presence of light chain β2m and HLA-A2-restricted peptide antigens. The refolded A2monomers were biotinylated with a commercial biotinylation enzyme (BirA) and purified by low pressure anion exchange chromatography on a Q-Sepharose (fast flow) column.The tetramers were then formed by mixing A2 monomers with streptavidin-PE in a molar ratio of 4:1. Flow cytometry was used to confirm the expected tetramer staining of CD8+ T cells.RESULTS: Recombinant genes for HLA-A*0201 heavy chain (A2) fused to a BirA substrate peptide (A2-BSP) and mature β2m from HLA-A2+ donor leukocytes were successfully doned and highly expressed in E. coli. Two soluble monomeric A2-peptide complexes were reconstituted from A2-BSP in the presence of β2m and peptides loaded with either human cytomegalovirus pp65495-503 peptide (NLVPMVATV,NLV; designated as A2-NLV) or influenza virus matrix protein Mp58-66 peptide (GILGFVFTL, GIL; designated as A2-GIL). Refolded A2-NLV or A2-GIL monomers were biotinylated and highly purified by single step anion exchange column chromatography. The tetramers were then formed by mixing the biotinylated A2-NLV or A2-GIL monomers with streptavidin-PE, leading to more than 80% multiplication as revealed by SDS-PAGE under non-reducing, unboiled conditions. Flow cytometry revealed that these tetramers could specifically bind to CD8+ T cells from a HLA-A2+ donor,but failed to bind to those from a HLA-A2- donor.CONCLUSION: The procedure is simple and efficient for generating peptide-MHC tetramers.

Glypican-3-specific cytotoxic T lymphocytes induced by human leucocyte antigen-A*0201-restricted peptide effectively kill hepatocellular carcinoma cells in vitro

Objective: To investigate potential human leucocyte antigen(HLA)-A2-restricted epitope peptides of glypican-3(GPC3) and determine the cytotoxicity of peptidespecific cytotoxic T lymphocytes(CTLs) against hepatocellular carcinoma(HCC) cells.Methods: The potential HLA-A*0201-restricted GPC3 peptides were screened using computer algorithms, T2 cell-binding affinity and stability of peptide/HLA-A*0201 complex assay. The peptide-specific CTLs were generated and their cytotoxicity against GPC3+SMMC 7721 and Hep G2 cells was detected using IFN-g based enzymelinked immunospot and lactate dehydrogenase release assays in vitro.Results: A total of six peptides were identified for bindings to HAL-A2 and the GPC3522–530 and GPC3 229–237 peptides with HLA-A*0201 molecules displayed high binding affinity and stability. The CTLs induced by the GPC3 522–530 or positive control GPC3 144–152 peptide responded to the peptide by producing IFN-g, which were abrogated by treatment with anti-HLA-A2 antibody. The GPC3 522–530-specific CTLs responded to and killed SMMC 7721 and Hep G2 cells, instead of GPC3-silenced SMMC7721 or Hep G2 cells. GPC3 522–530-specific CTLs response to HCC cells was blocked by anti-HLA-A2 antibody.Conclusions: The GPC3 522–530 peptide contains antigen-determinant and its specific CTLs can effectively kill HCC in a HLA-A2-restricted and peptide-dependent manner. Our findings suggest that this peptide may be valuable for development of therapeutic vaccine.

Construction of HA-1-DC Nucleic-acid Vaccine and Induction of Specific Cytotoxic T Lymphocytes

An HA-1-DC nucleic-acid vaccine was constructed to induce anti-leukemia effect after hematopoietic stem cell transplantation (HSCT). DCs were generated from HSCT donors in vitro, and its immunologic activity was assayed by using flow cytometry and mixed lymphocytes reaction. HA-1 gene was electroporated into the cultured DCs to construct a DC nucleic-acid vaccine. After transfection for 48 h, the expression of HA-1 protein could be detected by using Western blot. The DCs were cultured with syngenic lymphocytes to induce specific cytotoxic T lymphocytes (CTLs). The cytoxicity of the CTLs was detected by LDH assay. The results showed that The DCs derived from peripheral blood monocytes (PBMCs) expressed the phenotype of DCs, and were effective in stimulating proliferation of the allogenic lymphocytes. After electroporating for 48-h, HA-1 protein was detected by using Western blot. The cytotoxity of inducing CTLs was higher than the control group. It was suggested that minor histocompatibility antigen HA-1 could be considered as a target of immunotherapy against leukemia after HSCT.

Effect of Chinese Herbal Medicinal Ingredients on IL-2 mRNA Levels of T Lymphocytes in Mice Measured Using Semiquantification RT-PCR

In this study, the IL-2 mRNA levels of T lymphocytes in normal mice stimulated by nine Chinese herbal medicinal ingredients （CHMIs） were measured using semiquantification reverse transcription polymerase chain reaction. The results showed that astragalus polysaccharide （APS）, epimedium polysaccharide （EPS）, Chinese angelica polysaccharide （CAPS）, propolis flavone （PF）, and astrogalosides （AS） promoted IL-2 mRNA levels in T lymphocytes in vitro and in vivo to differing degrees, and the level of IL-2 mRNA induced by propolis polysaccharide （PPS） in vitro was higher than that induced by the control, which differed from that of PPS in vivo.

Ambiguous nucleus regulates the proliferation and percentage of T lymphocytes in peripheral blood

The aim of this study was to examine the immunomodulatory role of the unilateral ambiguous nucleus （Amb）. We performed electrical stimulation of the unilateral Amb, electrical stimulation of the left parietal cortex and the lateral hypothalamus following unilateral Arab lesion, as well as microinjection of acetylcholine chloride and hemicholine-3 into the unilateral Amb, and electrical stimulation of the unilateral Amb after injection of atropine, mecamylamine, propranolol, and phentolamine. Results showed that the number and proliferation of peripheral blood T lymphocytes were increased after electrical stimulation of the unilateral Arab. The cholinergic neurons in the Amb released choline substances to alter cellular immunity, thus confirming that the Amb mediates the neuro-immunomodulatory process.

Cross-talk between hepatic stellate cells and T lymphocytes in liver fibrosis

Background: Fibrosis results from inflammation and healing following injury. The imbalance between extracellular matrix(ECM) secretion and degradation leads to the ECM accumulation and liver fibrosis. This process is regulated by immune cells. T lymphocytes, including alpha beta( αβ) T cells, which have adaptive immune functions, and gamma delta( γδ) T cells, which have innate immune functions, are considered regulators of liver fibrosis. This review aimed to present the current understanding of the cross-talk between T lymphocytes and hepatic stellate cells(HSCs), which are the key cells in liver fibrosis. Data sources: The keywords "liver fibrosis", "immune", and "T cells" were used to retrieve articles published in Pub Med database before January 31, 2020. Results: The ratio of CD8 +(suppressor) T cells to CD4+(helper) T cells is significantly higher in the liver than in the peripheral blood. T cells secrete a series of cytokines and chemokines to regulate the inflammation in the liver and the activation of HSCs to influence the course of liver fibrosis. In addition, HSCs also regulate the differentiation and proliferation of T cells. Conclusions: The cross-talk between T cells and HSCs regulates liver fibrosis progression. The elucidation of this communication process will help us to understand the pathological process of liver fibrosis.

INVESTIGATION OF INDUCING EFFECT OF SPECIFIC CYTOTOXICITY OF CTLS BY ANTIGEN PEPTIDES FROM T LYMPHOCYTIC LEUKEMIA CELLS

Objective: To investigate the characteristics of specific antitumor immunity induced by antigen peptides mixture from T lymphocytic leukemia cells. Method: Antigen peptides mixtures were prepared from different leukemia cell lines and then bound with Hsp70 in vitro. Human peripheral blood mononuclear cells (PBMC) were cultured in vitro, and activated with Hsp70-antigen peptides. The activated PBMC was cultured continuously in vitro, and used as effector cells in vitro test of cytotoxicity to different target cells. Results: The antigen peptides from different leukemia cell lines were peptides mixture and could activate PBMC effectively if they were presented by Hsp70. The activated PBMC could proliferate in the presence of IL-2 and Hsp70-antigen peptides. The proliferative PBMC had specific cytotoxicity to leukemia cells corresponding to the antigen peptides. PBMC activated by antigen peptides from T lymphocytic leukemia cell lines could effectively kill T lymphocytic leukemia cells, and the cytotoxicity of these PBMC to T lymphocytic leukemia cells was significantly stronger than that of PBMC activated by antigen peptides from other leukemia cells (P < 0.05). PBMC activated by either Hut78-peptides or Molt 4-peptides could effectively kill Jurkat cells. And the cytotoxicity of PBMC activated by Hut78/Molt-4-peptides to Jurkat cells was significantly stronger than that of PBMC activated by either Hut78-peptides or Molt-4-peptides alone (P<0.05). Conclusion: Antigen peptides mixture from T lymphocytic leukemia cell lines can induce specific cytotoxic effect to T lymphocytic leukemia cells. There exists cross-reactivity among antigen peptides mixture from different T lymphocytic leukemia cell lines. The cross-reactivity could be amplified by blending of different antigen peptides from different T lymphocytic leukemia cell lines, suggesting that it is possible to prepare broad-spectrum antigen peptide vaccine against T lymphocytic leukemia by using multiple leukemia cell lines.

THE ADAPTABLE CHANGE OF THE FUNCTION OF T LYMPHOCYTES FOR PHYSICAL EXERCISE WITH OXYGEN

Objective To find out the possible regularity and mechanism of the adaptable change of human be- ing T lymphocytes for physical exercise with oxygen and bring the original data for the Movement of All People Im- proving their Health. Methods We selected 16 untrained female students in university and let them had the same amount of exercise for 8 weeks. After that, we collected the cycle blood at the time point or before exercise, the end of exercise and 1 hour after exercise at the end or the 0,first, 2 nd, 4 nd, 6 nd and 8 nd week respectively, so as to de- termine its stimuli index (SI) by MTT method. Results In the different time sect, such as the early stage or exer- cise, quiet condition,as soon as the end of exercise and 1 hour after exercise, we found that the SI were obviousIy low- er than that or normal (P<0.05),especially in the time sect of the end or exercise. Continuing to 4 weeks,the func- tion of T lymphocytes restored gradualy and it lasted to the 8th week, the SI in quiet condition and 1 hour after exer- cise had restored to normal (P>0.05),but in the end or exercise, it still was low,however. the extent of the cases se- lected was in a condition or acute excitability. Conclusion As the bodies adapting to the exercise, the function of T lymphocytes restored slowly and the rate increased faster and faster.

Correlation analysis of TCM syndrome types with T lymphocytes and biochemical indices in patients with HBV-related primary liver cancer

Objective:To investigate the correlation between T lymphocytes and biochemical indices in patients with Primary liver cancer(PLC)associated with hepatitis B virus(HBV)and TCM syndrome differentiation.Methods:263 HBV-related PLC patients who were admitted to the First Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2018 to December 2019 were retrospectively collected.There were 127 cases of liver depression and spleen deficiency syndrome(48.3%),48 cases of spleen deficiency and dampness syndrome(18.3%),31 cases of liver and gallbladder dampness and heat syndrome(11.8%),35 cases of liver and blood stasis syndrome(13.3%),and 22 cases of liver and kidney Yin deficiency syndrome(8.4%).The general data,T cell subsets,oncology and virology indicators,oncology characteristics,biochemical indicators and other data were counted.Epidata and Excel were used to collect and summarize the data,and SPSS26.0 software was used for statistical analysis.Results:There was no significant difference in gender and age distribution among the five syndrome types(χ^(2)=5.462,F=1.979,ALL P>0.05).The differences among T lymphocyte count(χ^(2)=57.785,P<0.001),CD4(+)T cell count(χ^(2)=47.103,P<0.001)and CD8(+)T lymphocyte count(F=12.760,P<0.001)were statistically significant.The T lymphocyte count,CD4(+)T lymphocyte count and CD8(+)T lymphocyte explicit count in patients with liver and kidney Yin deficiency syndrome were significantly lower than those in the other four syndrome types.AFP(χ^(2)=89.986,P<0.001),CEA(χ^(2)=95.501,P<0.001),CA199(χ^(2)=30.044,P<0.001)of the five syndrome types increased successively from the syndrome of liver depression and spleen deficiency to the syndrome of liver and kidney Yin deficiency,and the difference was statistically significant.There were statistically significant differences in the inner diameter of main portal vein,portal vein cancer thrombin and extrahepatic metastasis among the five syndrome types(ALL P<0.001).The main symptoms of portal vein cancer thrombin and extrahepatic metastasis were liver-gallbladder dampness-heat syndrome and liver-blood stasis syndrome.The differences among PLT(χ^(2)=39.234,P<0.001),Alb(χ^(2)=75.171,P<0.001),TBil(χ^(2)=51.140,P<0.001),AST(χ^(2)=55.881,P<0.001),PT(χ^(2)=21.515,P<0.001)were statistically significant.PLT and Alb decreased successively from the syndrome of liver depression and spleen deficiency to the syndrome of liver and kidney Yin deficiency.PLT and Alb of the syndrome of liver depression and spleen deficiency were significantly higher than those of the other four groups,and TBil and AST of the syndrome of liver and gallbladder dampness and heat were significantly higher than those of the other four groups.PT of liver and kidney Yin deficiency was significantly higher than that of the other four groups.The lymphocyte count,CD4(+) lymphocyte count and CD8(+) lymphocyte count were negatively correlated with AFP,PT and TBil(ALL P<0.05),and positively correlated with PLT(P<0.05).T lymphocyte count was positively correlated with AIb(P<0.05).Conclusion:This study found that patients with liver depression and spleen deficiency syndrome have better cellular immune function,liver function and prognosis.Patients with liver and kidney Yin deficiency have lower cellular immunity,worse liver function,and worse prognosis.Portal vein carcinoma embolus and extrahepatic metastasis were mainly characterized by dampness and heat of liver and gallbladder and blood stasis of liver.Patients with lower lymphocyte counts have poorer blood clotting,worse the liver reserve,and the higher the risk of further cancer.

Demethylating agent decitabine induces autologous cancer testis antigen specific cytotoxic T lymphocytes in vivo

Background Cancer testis antigens （CTAs） are a novel group of tumor associated antigens.Demethylating agent decitabine was reported to be able to up-regulate CTAs through its hypomethylation mechanism,thus enhance the immunogenicity of leukemia cells.However,few researches have ever focused on the questions that whether this immunostimulatory effect of decitabine could induce autologous CTA specific cytotoxic T lymphocytes （CTLs） in vivo,and if so,whether this effect contributes to disease control.In this study,we aimed to show that decitabine could induce specific autologous CTLs against some mouse CTAs in leukemia cells in vitro and in vivo.Methods Several mouse CTAs were screened by RT-PCR.CTL specific to one of the CTAs named P1A was detected and sorted by P1A specific dimer by flow cytometry.The activity of specific CTLs was measured by real time RT-PCR.Results We firstly screened expression of some CTAs in mouse leukemia cells before and after decitabine treatment and found that decitabine treatment did up-regulate expression of many CTAs.Then we measured the CTLs＇ activity specific to a mouse CTA P1A in vivo and showed that this activity increased after decitabine treatment.Finally,we sorted these in vivo induced P1A specific CTLs by flow cytometry and demonstrated their cytotoxicity against decitabine treated leukemia cells.Conclusions Our study showed the autologous immune response induced by decitabine in vivo.And more importantly,we firstly proved that this response may contribute to disease control.We believe that this immunostimulatory effect is another anti-cancer mechanism of decitabine,and this special effect would inspire new applications of decitabine in the field of leukemia treatment in the future.

High mobility group box 1 protein (HMGB1) as an immune-modulating factor for polarization of human T lymphocytes

Objective This study was performed to investigate the effect of high mobility group box-1 protein (HMGB1) on immune function of human T lymphocytes in vitro and explore its potential role in cell-mediated immune dysfunction. Methods Fresh blood was obtained from healthy adult volunteers and peripheral blood mononuclear cells (PBMCs) were isolated, then rhHMGB1 was added to PBMCs. Four-color flow cytometric (FCM) analysis was used for the measurement of intracellular cytokine including interleukin IL-4 and interferon IFN- ? ELISA kits were employed for the determination of IL-2 and sIL-2R protein levels in cell culture supernatants. Results (1) Different stimulating time and dosage of rhHMGB1 did not alter the number of IFN- αpositive cells (Th1). rhHMGB1 stimulation provoked a dose-dependent and time-dependent increase in Th2 subset and decrease in ratio of Th1 to Th2. (2) Compared with the untreated cells, when the cells were coincubated with rhHMGB1 (10-100ng/ml) for 12 hrs, protein release of IL-2 and sIL-2R were significantly up-regulated. At 48 hrs, in contrast, protein production was relatively lower in cells after exposure to 100-1000 ng/ ml rhHMGB1. Conclusions These findings demonstrated that HMGB1 has a dual influence on immune functions of human T lymphocytes.

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC)vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d).METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization,the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d.The survival rate and living time of mice were also calculated.RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) %, which were significantly higher than those of mice injected with water.The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered.CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc.Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.

Effect of IFNα-2a on Fas expression and apoptosis rate of peripheral blood cytotoxic T cells in patients with hepatitis B

Interferon(IFN) with antiviral and im-munomodulatory activities is one of the most important therapeutic agents for the treatment of chronic hepatitis. The apoptotic effect of IFN is influenced by cell type and the types of IFN, which suppresses proliferation and induces apoptosis in some cell types while inhibiting apoptosis in others. The aim of this study was to explore the effect of IFNα-2a on Fas expression and the apoptosis rate of peripheral blood cytotoxic T cells (CTLs) in patients with hepatitis B. METHODS:Peripheral blood mononuclear cells were isolated from 26 patients with hepatitis B including 16 patients with chronic hepatitis B and 10 patients with chronic severe hepatitis B. Fas expression and apoptosis rate of CTLs were analyzed with flow cytometry before and after IFNα-2a treatment. RESULTS:Before IFNα-2a treatment, Fas expression and apoptosis rate of CTLs from patients with chronic hepatitis B were significantly higher than those from patients with chronic severe hepatitis B and healthy controls respectively. No significant difference was observed between Fas expression and apoptosis rate of CTLs from patients with chronic severe hepatitis B and healthy controls. After IFNα-2a treatment,Fas expression and apoptosis rate of CTLs from different groups were compared with those before IFNα-2a treatment, showing no significant difference despite alternation of different degree. CONCLUSIONS:Activation induced cell death (AICD) exists in peripheral blood CTLs from patients with hepatitis B. No effect of IFNα-2a exerts on Fas expression and apoptosis rate of Fas in patients with hepatitis B.

Dendritic cells engineered to secrete anti-Dc R3 antibody augment cytotoxic T lymphocyte response against pancreatic cancer in vitro

AIM To investigate the enhanced cytotoxic T lymphocyte responses against pancreatic cancer(PC) in vitro induced by dendritic cells(DCs) engineered to secrete anti-DcR 3 monoclonal antibody(mA b).METHODS DCs, T lymphocytes and primary PC cells were obtained from PC patients. DCs were transfected with a designed humanized anti-Dc R3 monoclonal antibody heavy and light chain m RNA and/or total tumor RNA(DC-tumor-anti-Dc R3 RNA or DC-total tumor RNA) by using electroporation technology. The identification, concentration and function of anti-DcR 3 mA b secreted by DC-tumor-anti-Dc R3 RNA were determined by western blotting and enzyme-linked immunosorbent assay. After co-culturing of autologous isolated PC cells with target DCs, the effects of secreting anti-DcR 3 mA b on RNA-DCs' viability and apoptosis were assessed by MTT assay and flow cytometry. Analysis of enhanced antigen-specific immune response against PC induced by anti-DcR 3 mA b secreting DCs was performed using a 51 Cr releasing test. T cell responses induced by RNAloaded DCs were analyzed by measuring cytokine levels, including IFN-γ, IL-10, IL4, TNF-α and IL-12.RESULTS The anti-Dc R3 m Ab secreted by DCs reacted withrecombinant human Dc R3 protein and generated a band with 35 k Da molecular weight. The secreting m Ab was transient, peaking at 24 h and becoming undetectable after 72 h. After co-incubation with DCtumor-anti-Dc R3 RNA for designated times, the Dc R3 level in the supernatant of autologous PC cells was significantly down-regulated(P < 0.05). DCs secreting anti-Dc R3 m Ab could improve cell viability and slow down the apoptosis of RNA-loaded DCs, compared with DC-total tumor RNA(P < 0.01). The anti-Dc R3 m Ab secreted by DC-tumor-anti-Dc R3 RNA could enhance the induction of cytotoxic T lymphocytes(CTLs) activity toward RNA-transfected DCs, primary tumor cells, and PC cell lines, compared with CTLs stimulated by DC-total tumor RNA or control group(P < 0.05). Meanwhile, the antigen-specific CTL responses were MHC class I-restricted. The CD4+ T cells and CD8+ T cells incubated with anti-DcR 3 mA b secreting DCs could produce extremely higher level IFN-γ and lower level IL4 than those incubated with DC-total tumor RNA or controls(P < 0.01).CONCLUSION DCs engineered to secrete anti-Dc R3 antibody can augment CTL responses against PC in vitro, and the immune-enhancing effects may be partly due to their capability of down-regulating DC apoptosis and adjusting the Th1/Th2 cytokine network.

The injury progression of T lymphocytes in a mouse model with subcutaneous injection of a high dose of sulfur mustard

Background: In clinical studies, the findings on sulfur mustard(SM) toxicity for CD3+CD4+ and CD3+CD8+ T lymphocyte subsets are contradictory. In animal experiments, the effect of SM on the T cell number and proliferation is incompatible and is even the opposite of the results in human studies. In this study, we observed the dynamic changes of T lymphocytes in the first week in a high-dose SM-induced model.Methods: Mice were exposed to SM by subcutaneous injection(20 mg/kg) and were sacrificed 4 h, 24 h, 72 h and 168 h later. Spleen T lymphocyte proliferation was evaluated by 3H-Td R. Flow cytometric analysis was used to observe the percentage of CD3+CD4+ and CD3+CD8+ T lymphocyte subsets. The IL-1e assayed using the Luminex method. DNA damage in bone marrow ceβ, IL-6, IL-10 and TNF-lls was observed with α levels in plasma werthe single cell gel electrophoresis technique(SCGE).Results: SM continuously inhibited the proliferation of lymphocytes for 7 days, and there was a significant rebound of Con A-induced T lymphocyte proliferation only at 24 h. The percentage of CD3+CD4+ and CD3+CD8+ lymphocytes was upregulated, which was accompanied by increased IL-1β and TNF-creased in the PG group at 4 h. The peak of lymphocytic apoptα and decreased IL-10. The IL-6 level was gradually deosis and DNA damage occurred at 24 h and 72 h, respectively. Conclusion: Our results show that SM significantly inhibited T lymphocyte proliferation as well as induced CD3+CD4+ and CD3+CD8+ upregulation. SM intoxication also significantly increased the levels of pro-inflammatory cytokines(IL-1β, IL-6 and TNF-α) and inhibited the level of anti-inflammatory cytokine IL-10. Our results may partly be due to the significant SM induced significant apoptosis and necrosis of lymphocytes as well as DNA damage of bone marrow cells. The results provided a favorable evaluation of SM immune toxicity in an animal model.

Influence of REV and ALV-J Co-Infection on Immunologic Function of T Lymphocytes and Histopathology in Broiler Chickens

The aim of present investigation is to study the effect of single- and co-infection with REV and ALV-J on T lymphocytes bioactivities and histopathology in broiler chickens. The bioactivities of blood and spleen T lymphocytes including lymphoproliferation responses, cytotoxicitic responses, and histopathology of spleen were detected in broiler chickens singly- or co-infected with REV and ALV-J at different days post inoculation and the virus expressions in spleen of infected broiler chickens were detected with immunofluorescence assay （IFA）. The results indicated that blood and spleen T lymphocytes proliferation responses and cytotoxicity in broilers infected with REV or/and ALV-J were inhibited in the whole observed period compared with controls. In the co-infected chickens they were highly inhibited than in the single-infected. The histopathology of spleen in infected chickens at 17 and 37 d post inoculation （dpi） indicated that cell interium increased, the numbers of lymphocytes decreased, and the regrowth were destroyed or decreased, especially more significantly at 17 than at 37 dpi. The different numbers of virus were detected in spleen lymphocytes in REV- infected and/or ALV-J-infected chickens. In the spleen of co-infected chicken, both REV and ALV-J were detected and the total numbers of viruses were more than in chickens singly-infected with REV or ALV-J. Thus, the co-effect of REV and ALV-J caused more immunosuppression on T lymphocytes bioactivities in broiler chickens than single-effect of ALV-J or REV, which contributed to the sever histopathology and the product of tumor cells. This study will be helpful for understanding the effect of co-infection with many viruses and control them in poultry.

Association of Graves’ disease and Graves’ ophthalmopathy with the polymorphisms in promoter and exon 1 of cytotoxic T lymphocyte associated antigen-4 gene

Objective: To investigate the association of Graves’ disease and Graves’ ophthalmopathy with the C/T transition polymorphism at position –318 of promoter and the A/G transition polymorphism at position 49 of exon 1 within cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene. Methods: Thirty-three patients with ophthalmopathy of Graves’ disease, fifty-six Graves’ patients without ophthalmopathy and sixty normal subjects as control were involved in the present case-control study. The polymorphisms were evaluated by polymerase chain reaction fragment length polymorphism (PCR-RFLP). Com-parisons were made of gene frequencies and allele frequencies between the groups. Results: The gene frequencies of CT and allele frequencies of T were much higher in Graves’ patients with ophthalmopathy than that in the group without ophthalmopathy (P=0.020, P=0.019). The gene frequencies of GG and allele frequencies of G in patients with Graves’ disease were significantly increased as compared with control group (P=0.008, P=0.007). The data suggest that smokers with Graves’ disease seemed to be more predisposed to ophthalmopathy than non-smokers (P=0.018). Conclusion: Our results suggest that an allele of T at position –318 of promoter is associated with genetic susceptibility to Graves’ ophthalmopathy while an allele of G at position 49 of exon 1 is associated with genetic susceptibility to Graves’ disease instead. Smoking is believed to be a major risk factor for ophthalmo-pathy.