This study was purposed to investigate the value of combination of pentamer and intracellular IFNgamma staining in the qualitative and quantitative detection of circulating antigen-specific T cells. WT1 expressions in 14 HLA-A*0201+ patients and their matched donors were detected by RT-PCR, and circulating WT1 specific T cells were assayed by HLA-A*0201/WT1 pentamer combined with intracellular IFNgamma+ staining. The results showed that the low level of WT1 expression was found only in 2 cases out of 14 donors, but different levels of WT1 expression could be observed in all leukemic patients. The WT1+CD8+ CTL and WT1+IFNgamma+ cells did not detected in all 14 donors, but WT1+CD8+ CTL cells in 2 patients and WT1+IFNgamma+ cells in 3 patients could be detected before transplantation respectively, there was no significant difference between them, while the WT1+CD8+ CTL cells and WT1+IFNgamma+ cells both could be detected in all 14 patients after transplantation, the positive detection rate after transplantation was obviously higher than that before transplantation. The WT1+CD8+ and WT1+ IFNgamma+ cells could be detected within 30 days after transplantation, but the positive detection rate of WT1+IFNgamma+ cells was higher than that of WT1+CD8+ CTL cells (p=0.014). The median peak value of WT1+CD8+ CTL cells was 0.18% in 14 patients, and the median peak value of WT1+IFNgamma+ cells was 0.83% in 14 patients, the later was significantly higher than former. The median peak time of WT1+CD8+ CTL cells was 75 days after transplantation, while the WT1+IFNgamma+ cells was 105 days after transplantation, there was no significant difference between them. It is concluded that pentamer and intracellular IFNgamma staining may effectively detect circulating WT1 specific T cells in leukemic patients, and the combination of these two methods profit to the exact qualitation and quantitation of circulating antigen-specific T cells.
Adolescent ; Adult ; Child ; Female ; Flow Cytometry ; HLA-A Antigens ; analysis ; HLA-A2 Antigen ; Humans ; Interferon-gamma ; analysis ; Leukemia ; blood ; genetics ; immunology ; Male ; Middle Aged ; Staining and Labeling ; T-Lymphocytes, Cytotoxic ; immunology ; metabolism ; WT1 Proteins ; genetics ; immunology ; metabolism ; Young Adult

BACKGROUNDS/AIMS: Hepatitis B virus(HBV) specific cytotoxic T lymphocyte (CTL) response is believed to play a major role in virus control and liver damage in chronic hepatitis B(CHB). We performed this study to evaluate whether HBV specific CTL could be visualized directly by tetrameric HLA-A2/core 18-27 complex(T c18-27) in the peripheral blood and liver of patients with CHB. On the basis of our results we clarified patients intrahepatic compartmentalization and correlation with HBV specific CTL and viral replication or liver damage. METHODS: We stained peripheral blood mononuclear cells of 33 HLA-A2 + and 8 HLA-A2 patients with CHB with cychrome conjugated anti-CD8 mAb and phycoerythrin conjugated T c18-27. Among these we analysed intrahepatic lymphocyte of 11 HLA-A2 + patients. We compared the frequency of T c18-27 specific CD8+ cells with serum HBV-DNA levels or alanine aminotransferase(ALT) levels. RESULTS: The frequency of circulating T c18-27 specific CD8+ cell was higher(9-101 cells per 50,000 CD8+ cells) than background level in 14 among 33 patients. The frequency of intrahepatic T c18-27 specific CD8+ cells was 12-2100 cells per 50,000 CD8+ cells in 8 out of 11 patients whose liver was obtained This was 17.4-150 times higher than circulating T c18-27 specific CD8+ cells. The frequency of circulating T c18-27 specific CD8+ cells was increased in 10 out of 18 patients with serum HBV DNA level <0.5 pg/mL and ALT < 40 IU/L. It was increased in just 4 out of 15 patients with HBV DNA level > 800 pg/mL and ALT >70 IU/L. The frequency of intrahepatic T c18-27 CTL tended to be lower in high levels of serum HBV DNA and was not correlated with liver inflammation. CONCLUSION: This study provess that if HBV-specific CTLs are barely detectable in the peripheral blood of CHB, much more HBV-specific CTLs are in the liver and most HBV-specific CTLs are infiltrated in the liver. Also, in the presence of an effective HBV specific CD8 response the inhibition of viral replication can be independent of liver damage.
CD8-Positive T-Lymphocytes/immunology ; DNA, Viral/analysis ; English Abstract ; HLA-A2 Antigen/analysis/*immunology ; Hepatitis B Virus/genetics/*immunology ; Hepatitis B, Chronic/*immunology/virology ; Human ; T-Lymphocytes, Cytotoxic/*immunology ; Viral Core Proteins/*immunology

OBJECTIVETo identify a naturally presented HLA-A2-restricted epitope of MAGE-A3 antigen, FLWGPRALV (MAGE-A3(271 - 279)), on the surface of a human hepatocellular carcinoma (HCC) cell line HLE.

METHODSSynthetic peptide FLWGPRALV, served as positive control target, was analyzed by HPLC and HPLC-ESI-TOF-MSMS, in order to determine its HPLC elution time, mass-spectrometric characteristics and the lowest detection limitation by the two approaches. 3 x 10(9) HLE cells were collected, peptides naturally presented by major histocompatibility complex (MHC) molecules on the cell surface were isolated by mild acid elution, and concentrated by lyophilization, then the mixtures of peptides were fractioned by HPLC. The ingredient ranged from 2 min before the elution time determined by the synthetic peptide to 2 min after that was collected, concentrated by lyophilization, and analyzed by HPLC-ESI-TOF-MSMS, to identify the existence of the MAGE-A3(271 - 279) peptide.

RESULTSThe HPLC-ESI-TOF-MSMS detection provided an evidence for the existence of a doubly charged ion of (m/z)(2) 529.9, which was further analyzed by collision induced dissociation. The doubly charged ion was ultimately identified as the MAGE-A3(271 - 279) peptide, its amino sequence was FLWGPRALV and its molecular weight was 1058.4 Da.

CONCLUSIONSMAGE-A3(271 - 279) epitope could be naturally presented by HLA-A2 molecules to the surface of HCC cell line and MAGE-A3(271 - 279) peptide may have potential immunotherapeutic value in HCC patients.

Amino Acid Sequence ; Antigen Presentation ; Antigens, Neoplasm ; analysis ; isolation & purification ; Carcinoma, Hepatocellular ; immunology ; pathology ; Cell Line, Tumor ; Chromatography, High Pressure Liquid ; Epitopes, T-Lymphocyte ; analysis ; isolation & purification ; HLA-A2 Antigen ; immunology ; Humans ; Liver Neoplasms ; immunology ; pathology ; Mass Spectrometry ; Neoplasm Proteins ; analysis ; isolation & purification