Vitiligo is a disease in which melanocytes are selectively destroyed. The disease is thought to be an autoimmune process being there are antibodies to pigment cells in the sera of patients and animals with vitiligo. In the present study, sera from vitiligo patients were examined for reactivity with the human melanoma cell line, SK-Mel-28, by Western blot analysis of solubilized membrane antigens of these cells to identify the pigment cell antigens defined by antibodies in the patients with vitiligo. Antibody reactivity to human melanoma cells (SK-Mel-28) was investigated in 14 patients with vitiligo, and 16 with normal control individuals. Antibodies to the 116-113, 60, 40 KD antigens were associated with vitiligo being present in 79%, 86%, and 43% respectively of the patients with vitiligo, but in only 6%, 38% and 6% of the normal controls. In contrast, antibodies to the 160-155, 78 and 64 KD antigens were equally common in vitiligo and in normal individuals. The results suggest that autoreactivity to pigment cells occurs more commonly in patients with vitiligo than in the normal control and high autoreactivity to pigment cells in the vitiligo sera might be an impertinent epiphemenon to destroyed pigment cell.
Antibodies, Neoplasm/*blood ; Antigens, Neoplasm/immunology ; Autoantibodies/blood ; Blotting, Western ; Human ; Melanoma/*immunology ; Vitiligo/*immunology

Tumor antigen-specific cytotoxic T lymphocytes are important anti-cancer cells. The focuses of this review are to introduce the molecular basis of antigen presentation and CTL recognition, to summarize the identification of tumor associated antigens and their T cell epitopes, to highlight the current insights into the immunogenicity of TAA peptides and the principles of peptide-based vaccines against cancer, and to comment on future prospects for CTL therapy.
Animals ; Antigens, Neoplasm ; immunology ; Cancer Vaccines ; immunology ; Humans ; Immunotherapy ; Neoplasms ; immunology ; therapy ; T-Lymphocytes, Cytotoxic ; immunology

Antigens, Neoplasm ; immunology ; Cancer Vaccines ; immunology ; Carcinoma, Hepatocellular ; immunology ; therapy ; Humans ; Immunotherapy ; Liver Neoplasms ; immunology ; therapy

Antigens, Neoplasm ; metabolism ; Antigens, Surface ; metabolism ; Colorectal Neoplasms ; immunology ; pathology ; Humans ; Prognosis ; Trophoblasts ; immunology

PURPOSE: Vaccine strategies utilizing dendritic cells (DCs) to elicit anti-tumor immunity are the subject of intense research. Although we have shown that DCs pulsed with heat-treated tumor lysate (HTL) induced more potent anti-tumor immunity than DCs pulsed with conventional tumor lysate (TL), the underlying molecular mechanism is unclear. In order to explore the molecular basis of this approach and to identify potential antigenic peptides from pancreatic cancer, we analyzed and compared the major histocompatibility complex (MHC) ligands derived from TL- and HTL-pulsed dendritic cells by mass spectrophotometry. MATERIALS AND METHODS: Human monocyte-derived dendritic cells were pulsed with TL or HTL prior to maturation induction. To delineate differences of MHC-bound peptide repertoire eluted from DCs pulsed with TL or HTL, nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MS-MS) was employed. RESULTS: HTL, but not TL, significantly induced DC function, assessed by phenotypic maturation, allostimulation capacity and IFN-gamma secretion by stimulated allogeneic T cells. DCs pulsed with TL or HTL displayed pancreas or pancreatic cancer-related peptides in context of MHC class I and II molecules. Some of the identified peptides had not been previously reported as expressed in pancreatic cancer or cancer of other tissue types. CONCLUSION: Our partial lists of MHC-associated peptides revealed the differences between peptide profiles eluted from HTL-and TL-loaded DCs, implying that induced heat shock proteins in HTL chaperone tumor-derived peptides enhanced their delivery to DCs and promoted cross-presentation by DC. These findings may aid in identifying novel tumor antigens or biomarkers and in designing future vaccination strategies.
Antigens, Neoplasm/*immunology ; Cell Line, Tumor ; Dendritic Cells/*immunology ; Humans ; Pancreatic Neoplasms/*immunology

To obtain the NPC-associated antigens, a powerful new method, SEREX (serological identification of antigen by recombinant cDNA expression library), was used for identifying the antigens eliciting humoral immune response. Before performing serological analysis, a high quality cDNA library derived from human nasopharyngeal carcinoma (NPC) tissue was constructed. The primary library consisted of 3.64 x 10(6) recombinants and the recombinant rate was 94%. For better preserving the cDNA library, it was amplified. As a result, the titer of the amplified cDNA library was 3.8 x 10(9) pfu/mL. With SEREX method, immunoscreening for the detection of reactive clones in the human NPC tissue cDNA library was performed with autologous serum. As a result, 23 positive clones encoding antigenic genes were obtained after immunoscreening, and the nucleotide sequences of cDNA inserts were determined and analyzed with BLAST software in GenBank. Results showed that the 23 reactive clones were derived from 16 different genes. 10 of 16 genes had high homologous to the genes known in GenBank, such as RPL31, S100 A2, MT2A, etc. However, there were also 6 genes with low homology to the genes known in GenBank. Furthermore, 3 of 6 genes may be novel genes. The associations of these genes to NPC and the roles that they played in the occurrence and development of NPC should be revealed by further research.
Antigens, Neoplasm ; genetics ; Gene Library ; Humans ; Nasopharyngeal Neoplasms ; genetics ; immunology

Animals ; Antigens, Neoplasm ; immunology ; Apoptosis ; Cell Differentiation ; Humans ; Macrophages ; pathology ; Neoplasm Regression, Spontaneous ; immunology ; pathology ; physiopathology ; Neoplasms ; immunology ; pathology

OBJECTIVETo study the effectiveness of freeze-thaw antigens and acid eluted peptide antigens extracted from tumor cell-pulsed dendritic cells (DC) in inducing prostate cancer-specific cytotoxic T lymphocytes (CTL) in vitro.

METHODSTumor antigens were extracted from the prostate cancer cell line PC-3 with the repeated freeze-thaw and weak acid elution methods. Peripheral blood mononuclear cells were cultured with recombinant human GM-CSF and IL-4 for inducing DCs in vitro. Then the DCs were pulsed with the two kinds of prostate cancer tumor antigens respectively and cultured with T cells for inducing CTLs. The activity of the tumor-specific CTLs were detected by LDH release assay.

RESULTSThe protein content in the tumor antigens obtained from PC-3 (2 x 10(7)) by citric acid-phosphate buffer elution and that by the repeated freeze-thaw method were (212.2 +/- 7.9) microg and (963.0 +/- 25.3) microg, respectively. The two kinds of prostate cancer antigens-pulsed DCs had a significant role in inducing the PC-3 cell-specific CTLs, and the CTLs induced by acid-eluted peptide antigen-pulsed DCs exhibited an even more significant tumor-specific cytotoxicity than those induced by repeated freeze-thaw ([60.4 +/- 5.52]% vs. [43.7 +/- 4.11]%, P < 0.01).

CONCLUSIONBoth the weak acid elution and repeated freeze-thaw methods for extracting prostate cancer antigens can be used for in vitro sensitization of DCs. The DCs pulsed by either of the two kinds of antigens can activate CTLs, and the antigens extracted by weak acid elution are even more effective.

Antigens, Neoplasm ; immunology ; Cell Line, Tumor ; Dendritic Cells ; immunology ; Humans ; Male ; Prostatic Neoplasms ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

Exosomes are nanometer sized membrane vesicles, released in the extracellular milieu following the fusion of the external membrane of multivesicular body (MVB) with plasma membrane. They perform a certain function in immune regulation. Exosomes have been shown to be released by cells of hematopoietic and non-hematopoietic origin. Tumour-derived exosomes (TEX) exist in the supernatant of tumour cells, plasma and malignant effusions of tumour patients. They contain native candidate tumour associated antigen and are capable of transferring antigens to T lymphocytes, therefore efficiently promoting cytotoxic T lymphocyte (CTL) activation and producing antitumor immunity. However, recent evidence shows that tumor exosomes may induce immunologic tolerance and even activate immunosuppression which makes tumour escape from the immune surveillance of the host immune system. In addition, tumor exosomes may mediate a growth-promoting effect on tumor cells. These discrepancies are almost certainly due to differences in the phenotype of the exosomes.
Antigen-Presenting Cells ; immunology ; Antigens, Neoplasm ; immunology ; Cytoplasmic Vesicles ; immunology ; Endosomes ; immunology ; metabolism ; Exosomes ; immunology ; Humans ; Neoplasms ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Escape

ZCH-2B8a (IgG2a) is a novel monoclonal antibody (McAb) generated in laboratory of Children Hospital of Medical College, Zhejiang University recently using human myeloblastic leukemia cell line KG1a as immunogen. This antibody has been submitted to the 8th International Workshop and Conference on Human Leukocyte Differentiation Antigens (HLDA8) and the results showed that the antibody recognized an unknown molecule on the surface of some blood cells. The aim of this study was to investigate the reactivity of this antibody on normal blood cells and malignant cell lines and to explore its possible application in clinical practice. The multi-parameter flow cytometry was used to analyze the expression pattern of 2B8a antigen in triplicate on normal blood components including T cells, B cells, natural killers (NK), neutrophils, monocytes, dendritic cells (DC), red blood cells (RBC), platelets (Plt), hematopoietic stem/progenitor cells derived from either bone marrow or G-CSF mobilized peripheral blood CD34(+) cells and malignant cell lines including 14 hematopoietic, 5 neuroblastoma, 1 colon cancer and 1 amniotic epithelium cell lines. The amount of positive cells > or = 20% was considered as positivity. The results showed that 2B8a antibody reacted to 3/3 specimens of blood B cells with a positive rate of 26.29% and 2/3 specimens of monocytes with an average positive rate of 59.84%. 2B8a was weakly reactive to neutrophils (23.72%) and negative for T cells, NK, DC, RBC and Plt. The antibody reacted to all 3 marrow CD34(+) cells with an average positive rate of 39.33% while it was negative for G-CSF-mobilized CD34(+) peripheral blood stem/progenitor cells (PBSC, 1.25%). Cell line analysis showed that the antibody notably reacted to three out of 4 cell lines (Raji, SMS-SB, Nalm-6 and Nall-1) with the positive rates of 98.78%, 98.61%, 94.93% respectively and weakly to one of them with 5.68% in B lineage cell lines and monoblastic cell line (U937, 67.78%) while it was only weakly positive or negative for other myeloid leukemia cell lines including Meg01 (33.40%), HL-60 (29.70%), K562 (28.19%), KG1a (16.23%) and HEL92.1.7 (8.02%). Among 4 T lineage leukemia, 5 neuroblastoma and 1 colon cancer cell lines tested, only Molt-3 was found weakly positive (31.40%) for 2B8a, while the remaining 3 T cell lines (Molt4, JM and CCRF-CEM), 5 neuroblastoma cell lines (LA-N1, KCNR, BE, SK-N-SH, SK-N-AS) and the colon cancer cell line (HR8348) tested were negative. An amniotic epithelium cell line (FL) was showed positive for the antibody (45.03%). It is concluded that 2B8a antibody primarily reacts to B lineage and monocytic lineage cells which may bear the diagnostic and therapeutic applications among different types of hematopoietic malignancies.
Antibodies, Monoclonal ; biosynthesis ; immunology ; Antibody Specificity ; Antigen-Antibody Reactions ; Antigens, Neoplasm ; analysis ; immunology ; Antigens, Surface ; immunology ; B-Lymphocytes ; cytology ; immunology ; HLA Antigens ; immunology ; Hematopoietic Stem Cells ; cytology ; immunology ; Hematopoietic System ; cytology ; Humans ; Leukemia, Myeloid, Acute ; immunology ; pathology ; Tumor Cells, Cultured