Genetic susceprtibity to acute or chronic schistosomiasis japonica

点击翻译按钮获取中文摘要

1.Molecular cloning of the major antigens from a cDNA library of schistosomal egg by using patients pooled sera.We have already found there are relatively resistant and susceptible HLA-class II haplotypes present in the Chinese patients against post-schistosomal liver fibrosis. This 'ear we seeked for the major antigens that would stimulate those HLA haplotypes positive individuals' T cells, because T cell response is assumed to be the most important in the pathogenesis. A cDNA library was prepared from a mRNA extracted from the freshly isolated eggs of a Chinese strain using lambda gt11 I phage system and was screened for the major antigens reactive with pooled sera by IgG detection system. Finally 200 positive clones were isolated and 146 clones out of those were directly sequenced. The result was unexpected because all the clones were several parts of one gene named miracidial antigen. The cloned gene was successfully expressed by GST fusion protein system.2. Re-infection study in t … More hree different villages.We have found two things. One is that there was no age dependent resistance in the population and the other is that there were two categories of people present, resistant and susceptible against re-infection. We have found that the HLA-DRB1 types that resistant persons had shared its 67th amino acid, phenylalanine, instead of having 67 leucine or isoleucine. Because the 67F or I/L is important to make a binding pocket, it would be critical to provoke some protective immune response.3. Vaccination trial of domestic pigs with recombinant paramyosin in China.In the endemic area in China, it is important to control the infection of the reservoir hosts, such as pigs and water buffaloes. We have performed a vaccine trial study using domestic pigs and recombinant paramyosin. The extensive study using more than 80 pigs revealed that the pigs were susceptible to challenge infection and were provoked immunity against infection after the vaccination with paramyosin as well as with attenuated cercariae (Vaccine in Press). Less