[Activation of anti-tumor cytotoxic T lymphocytes by fusion of human dendritic cells and melanoma cells].

OBJECTIVE: To determine the effect of activation of specific anti-tumor cytotoxic T lymphocytes (CTL) and the ability of cross-presentation in vitro by fusion of HLA-A2+ human dendritic cells (DCs) with HLA-A2- melanoma cells. METHODS: The HLA-A2+ human dendritic cells and HLA-A2- melanoma cells were fused by PEG and were cultivated in complete RPMI1640 media containing FCS (10%) and GM-CSF for 24-48 h, and then co-cultured fusion cells with Melan-A specific T cells. HLA-A2- melanoma cells were negative control,While T2 cells and DC+Pts were positive control. The activation of anti-tumor CTL elicited by the fusion cells was detected by intracellular cytokine staining. RESULTS: The immature DC could express CD80, CD83, CD86, HLA-DR, and HLA-ABC,but the mature DC induced by TNF-alpha, PGE-2, and CD40L further highly expressed above molecules. The rate of specific CTL cells primed by the fusion cells was 16.72%+/-4.26%, negative control was 0.21%+/-1.84%,and positive control was 28.60%+/-5.67%. The CTL from vaccine by fusing DC and LAR6 induced lysis of HLA-A2+ LAR1 cells. CONCLUSION: The HLA-A2 restricted specific anti-tumor CTL can be induced in vitro by fusion of HLA-A2+ human dendritic cells with HLA-A2- melanoma cells.

[Effects of astragalus polysaccharides-chitosan/polylactic acid composite material on biological behavior of canine bone marrow stromal cells cultured in vitro].

OBJECTIVE: To observe the biological behavior of canine bone marrow stromal cells (BMSCs) cultured in vitro with the astragalus polysaccharides-chitosan/polylactic acid (AP-C/PLA) and with the chitosan/polylactic acid (C/PLA) and to find a suitable compound material for periodontal tissue engineering. METHODS: BMSCs (induced 14 days by 50 mg/L vitamine C, 10(-8) mol/L dexamethasone, 10 mmol/L beta-sodium glycerylphosphate) were cultured on AP-C/PLA or C/PLA for 5 days respectively. The BMSCs attachment and the morphology were observed with scanning electronic microscope and the combining rates were counted. Type I collagen synthesis was examined with immunohistochemistry staining and the content of osteocalin was determined with radio-immunological method. RESULTS: Combining rates, type I collagen synthesis, and the content of osteocalin of BMSCs on AP-C/PLA were significantly higher than those on C/PLA. CONCLUSION: AP-C/PLA may promote the BMSC proliferation, differentiation and extracellular matrix synthesis, and it can be used as a good scaffold material for bone tissue engineering.

[Establishment and characterization of a melanoma cell line HME1].

OBJECTIVE: To establish a melanoma cell line and identify its characteristics in vitro. METHODS: The tissues from biopsies of melanoma were performed primary culture. After growing to 90% confluence, the cells were detached and transferred to another flask for subculture, and then we identified their characteristics including growth kinetic, morphology and tumorigenecity. RESULTS: This cell line was cultivated for more than 90 times. Its characteristics were as follows:The pathological morphology of the tumor transplanted in nude mice were similar to that of the original lesion;The growth curves of the 20th passage were determined, and the population doubling time calculated was 56.9 h; The cloning efficiency in soft agar was 19.1%; Karyo-type analysis showed aneuploidy with the modal chromosomal number 85-102; Electronmicroscopical observation showed that there were rich microvilli on the surface of the cells, abundant ribosomes and melanoid grain; SP immunohistochemical staining showed that the cells expressed HMB-45. CONCLUSION: The Melanoma cells were immortalized after being cultured in vitro and a new melanoma cell line was established.

[Establishment and characteristics of the human diploid cell strain HLF-02].

OBJECTIVE: To establish the HLF-02 and provide a new material to the study of geronics, oncology, virology, pharmacology, and biogenetics. METHODS: The lung tissue was digested with 0.15% trypsin. More than 90% of the dissociated cell exhibited initial viability (trypan blue dye exclusion and the ability of adhesion). The surviving cells were analyzed by morphology, growth curves, karyotype analysis, electron microscopic observation and heterotransplantation. RESULTS: A newly established cell strain, which was designated HLF-02 had been maintained in continuous culture for over 50 generations for 10 months. Morphological observation, electron microscopic observation, karyotype analysis and heterotransplantation showed that it was corresponding to diploid cells. The doubling time of the cells was 75.5 hours. Chromosome analyses showed the human cell strain to be typical diploid appearance, and the tumorigenecity assays of nude mice were negative. CONCLUSION: The HLF-02 is a human dipolid cell strain and can serve the further studies of cell gerontics, oncology, virology, pharmacology, and biogenetics.