The goal of this projectis to contributeto efforts to develop defined antigen vaccinesfor schistosomiasis. This will be achieved by evaluating the immunogenicity and protective efficacy of promising S. bovis and S. japonicum antigens in their native bovine hostsin collaboration With professor Capron's group in Lille, France,and laboratories in Africa and China. Within our current EC supported programmeencouraging results have already been achieved with glutathione S-transferases (GSTs) against S. Bovis in calvesin Sudan and we proposeto repeatand extend this work t0 trials of recombinantderived Gstsin Africa. Likewise S.japonicum Gsts have shown promisein our ratimmunization experiments andthese will be extended to trials with both native and recombinantderived GSTs in bovines in China.In collaboration with our chinese colleagues we will study the mechanisms mediating GST induced protection against disease,in particular We will seek to modulate antifecundity and anti eggimmunity With monoclonal antibodies as has already been achieved by Dr.Xu Chuanbo Workingin Lille with S. Mansoni. Immunogenicity tests and vaccination trials will be carried out with KLH, which as Shown by Capron and colleagues,Shares a protective epitope with the non species specific S. mansoniantigen gp38. Since our Chinese colleague, professor Xu Shoutai has obtained excellent protection in bovines with crude freeze/thawed schistosomular antigens plus Bcgthis will be repeated and the immune response characterized. By extrapolation from work done on S. mansoni by Sher et al.in which a similar vaccination regimen was usedin rodents,the role ofthe protectige antigen,paramyosin,in vaccinated bovine immunity will be investigated. S. japonicum paramyosin will be cloned and the recombinantderived protein testedin bovines. Similar work will becarried out with S. bovis Sj23,the analogue of the S. mansoni antigen reported by Several research groups to be protective, will also be cloned and testedin vaccination trialsin bovines. In addition to these already identified "protective" antigens,recombinant derived antigens which we arein the process of characterizing, and novel antigens which will be identified by screening our CDNA libraries with various animal sera, will be evaluated in animal experiments.
Funding SchemeCSC - Cost-sharing contracts