ABSTRACT
<p><b>OBJECTIVE</b>To explore the variations of gene C in hepatitis B viruses between hepatitis B patients and healthy carriers, and provide experimental evidences for analysis of virus gene mutations acting on the virus material science and response of the body to the virus.</p><p><b>METHODS</b>The virus DNA load in hepatitis B patients and healthy blood donors was investigated by real-time polymerase chain reaction (PCR). Gene sequence analysis was taken to detect gene polymorphism, and all the success samples were compaired with standard strain by DNAstar.</p><p><b>RESULTS</b>(1)G Compared with standard strain, C region in all samples had mutations, there were 31 mutations in at least 2 samples (3 mutations in gene PreC and 28 mutations in gene C), including 9 missense mutations, 1 chain termination mutation and 21 synonymous mutation. Mutations nt 1827 c-->a and nt 2221 c-->t existed in all the samples, and most samples had 6 synonymous mutations. Four hepatitis B patients had mutation nt1896 g-->a, and another 4 patients had 2 mutations, namely, S87G and I97F (or 197L) in HBcAg CTL recognition episome. (2) The success ratio of amplification and sequencing of HBV DNA was closely associated with its copy numbers. In the present study, copy numbers of HBV DNA which were successfully amplified and sequenced were almost more than 40 193/ml.</p><p><b>CONCLUSIONS</b>HBV genome were easily affected by nucleotide mutations, 2 residues had mutations in gene of C region, which is firstly reported, suggesting these mutations may be geographical restricted. Mutations in gene of C region may either change the structure and function of HBeAg and HBcAg, which may further induce the escape of immune clearance for HBV or influence the detection of HBsAg or HBeAg, which may creat new problems for the prevention, diagnosis and treatment of hepatitis B.</p>
Subject(s)
Female , Humans , Male , Hepatitis B , Virology , Hepatitis B Core Antigens , Genetics , Hepatitis B virus , Genetics , Mutation , Polymorphism, GeneticABSTRACT
The aim of this study was explore the effect of natural killer (NK) cells on engraftment and reconstitution of hematopoiesis and immunity in mice undergoing allogeneic bone marrow transplantation (allo-BMT). Lethally and nonlethally irradiated BALB/c (H-2(d)) mice were transplanted with C57BL/6 (H-2(b)) bone marrow plus donor peripheral T cells and/or NK cells. Recipient CD34(+), H-2K(b+), CD3(+) and CD19(+) cells were detected by flow cytometry; peripheral blood leukocytes were counted by auto-cytometry; survival rates, engraftment, hematopoietic and immune recovery of recipients in different transplant groups were then observed. The results indicated that as compared with lethally irradiated and allo-BMT group without infusion of NK cells, the survival rate in lethally irradiated and allo-BMT group with infusion of NK cells significantly enhanced (survival rates at 60 days were 70% and 0.0% respectively); leukocyte count, expression level of CD19(+) cell and CD34(+) cell count recovered rapidly; expression level of H-2K(b+) cells obviously increased [(86.68 +/- 4.45)% vs (4.68 +/- 0.32)%]; expression level of CD3(+) cell at day 28 after transplantation obviously decreased [(33.69 +/- 3.36)% vs (50.40 +/- 5.06)%, p < 0.01], at day 60 there was not significant difference between the 2 groups (p > 0.05). In nonlethally irradiated and allo-BMT group without NK cell infusion, the expression level of H-2K(b+) at day 30 after transplantation significantly decreased, and reduced to level before transplantation at day 60; while expression of H-2K(b+) yet could be detected with > 80% at day 60 after transplantation in group infused with high and low concentration of NK cells. It is concluded that in allo-BMT mice, alloreactive NK cell inhibits graft rejection, enhances engraftment, promotes the reconstitution of hematopoiesis and immunity, and increases survival rates.