Common linear B-cell epitopes in human hepatitis B virus core protein and woodchuck hepatitis virus core protein / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To search for and verify some common B cell epitopes in the core proteins of woodchuck hepatitis virus and human hepatitis B virus.</p><p><b>METHODS</b>Monoclonal antibodies against both core proteins of woodchuck hepatitis virus (WHV) and human hepatitis B virus (HBV) were prepared by inoculating Balb/c mice with denatured recombination WHV and HBV core proteins. ELISA and immunoblotting assays for WHcAg and HBcAg were carried out by using these antibodies. Immunohistochemistry was carried out with liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients. The epitopes were mapped with the mouse mAbs (6D1 and 1H4) by using a panel of 24 16mer overlapping peptides covering the entire WHcAg. The amino acid sequences of WHcAg and HBcAg were compared.</p><p><b>RESULTS</b>Cross-reactions were observed between mAbs (6D1 and 1H4) and WHcAg and between Mabs and HBcAg/HBcAg in ELISA and immunoblotting assay. Liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients could be stained specifically by mAbs. The epitopes were mapped at aa1-8 (6D1) and aa125-140 (1H4) of the core proteins of both WHV and HBV by using ELISA assay. WHcAg and HBcAg share similar amino acids sequences at aa1-8 and aa125-140 respectively.</p><p><b>CONCLUSION</b>The core proteins of woodchuck hepatitis virus and human hepatitis B virus share common linear B cell epitopes which span aa1-8 and aa125-140 respectively.</p>

Proliferation and apoptosis in vitro of umbilical cord blood CD34+CD38- hematopoietic early progenitor cells / 中国实验血液学杂志

To cultivate CD34(+)CD38(-) cells isolated from umbilical cord blood of healthy puerperal women over a longer-period of time for observation of cell division, proliferation, apoptosis, and effects of stem cell factor on the growth of CD34(+)CD38(-) cells, with flow cytometry, CD34(+)CD38(-) cells were isolated from umbilical cord blood of 10 healthy puerperal women and cultivated in stem cell media with supplement of IL-3, IL-6, GM-CSF, EPO, IGF-1 and SCF 6 kinds cell growth stimulating factors for six months. The cell growth curves were established. The effects of stem cell factor on the growth of CD34(+)CD38(-) cells and cell apoptosis were investigated with the single cell gel electrophoresis technique and flow cytometry method, respectively. The results showed that CD34(+)CD38(-) cells isolated from umbilical cord blood were capable of proliferating after being cultivated in vitro over a longer-period of time with no evidence of the presence of excessive apoptosis. In conclusion, under appropriate culture conditions, CD34(+)CD38(-) hematopoietic early progenitor cells from umbilical cord blood can serve as a resource providing a large amount of primitive cells for transplantation therapy after a longer period of cultivation and proliferation in vitro.

Karyotyping and immunophenotyping analyses of the CD34+ CD38- cells isolated from human umbilical cord blood / 中华血液学杂志

<p><b>OBJECTIVE</b>To cultivate hematopoietic stem/progenitor cells (CD34(+)CD38(-)) isolated from umbilical cord blood (UCB) long for the observation of cell growth and expansion in vitro, surface marker expression, and chromosomal complements.</p><p><b>METHODS</b>By flow cytometry CD34-FITC and CD38-PE labeled CD34(+) and CD38(-) stem/progenitor cells were isolated from UCB. The cells were cultivated in vitro for 6 months in a stem cell culture system with addition of six kinds of cell growth factors (IL-3, IL-6, GM-CSF, Epo, SCF, IGF-1). One month after cultivation, cultured cells were investigated for surface marker expression by flow cytometry and karyotype by G banding method.</p><p><b>RESULTS</b>After 7-12 days cultivation, the CD34(+)CD38(-) stem/progenitor cells began proliferation. The proliferation rate and the peak proliferation duration were greater in 1 cell/well cultivation conditions than in 10 cells/well. The cells remained CD34(+)CD38(-) and their karyotypic characteristics remained unchanged.</p><p><b>CONCLUSION</b>CD34(+)CD38(-) stem/progenitor cells from UCB may provide a larger than original amount of stem/progenitor cells for transplantation after long-term cultivation in vitro.</p>

A brief introduction to the secretion mechanism in immunocytes / 生理学报

Exocytosis is a vital function of many cell types including neuron, endocrine cell and immunocyte. Secretion in immunocytes involves a complex process of signal transduction, in which many factors still remain unknown. In the last 10 years, this area has become an international hot spot of investigation, resulting in many break-through progresses. This progress was made possible by combined efforts in molecular biology, cell biology and biophysics. This review focuses on notable new knowledge and some new techniques in functional study of secretion in immunocytes.

Calcium-dependent modulatory effect of norepinephrine on the Ia antigen expression of the macrophage / 中国免疫学杂志

Fura—2 was used as a Ca~(2+) indicator to determine the intracellular calcium ion concentra-tion(〔Ca~(2+)〕i)of rat peritoneal macrophages(RPM?s),and APAAP enzyme immnoassay was ap-plied to detect the expression of Ia antigens on RPM?s.The results showed that norepinephrine(NE,10~(-9)mol/L)could markedly increase the〔Ca~(2+)〕i of the RPM?s(p