Studies On SLA-I Restricted CD8+T Antigen Epitope Of African Swine Fever Virus

African swine fever(ASF)is an acute,febrile,highly contagious and infectious disease of domestic and wild pigs caused by African swine fever virus(ASFV)with morbidity and mortality rates approaching 100 percent,which has not been reported in China as a potent disease of great importance.ASF has spread widely,leading to great economic losses of incoming countries ever since the outbreak in east-African country Kenya in 1921.ASF has been included into thelist of notifiable terrestrial and aquatic animal diseases by OIE,and listed as “Class A animal disease” in the catalogue of animal epidemics of China.There is no vaccine available for ASFV at present,because of which study for ASF vaccine is of great importance.There are reports about ASF vaccine research,however,classic vaccines such as inactivated vaccines,attenuated vaccines and subunit vaccines cannot protect infected animals effectively.It is reported currently that humoral immunity cannot offer protection for infected pigs effectively.It only delayed the clinic onset.T-cell responses,especially CD8+ Tcell responses,have been proved to be crucial in protection against ASF.The depletion of CD8+ T lymphocytes abrogates protective immunity to ASFV.We aimed toimprove cellular immunity.CD8+T recognize antigenic peptide presented by MHC-I of antigen presenting cells.Because of the critical role of cellular immunity mediated by CD8+T in this study,we aimed to find MHC-I restricted peptides of ASFV antigen and vaccines which can induce effective cellular immunity against ASF.The protein p72,p54,p30 and CD2 v is quite important structural proteins of ASFV.p72 is the major structural proteins of virus particles.p54 is essential for the early stage infection and survival of viruses and is involved in adhesion and entry.p30 is a phosphoprotein which bear a part in adhesion of ASFV to host cells.CD2 v has similar sequence with CD2 leukocyte molecule of host,It is requisite in adhesion of red blood cells to infected cells and virions.Its property of adhesion to red blood cells have important relationship with propagation of ASFV in vivo.Accordingly,we opt for the protein p72,p54,p30 and CD2 v as experimental subjects to study and screen SLA I-restricted antigenic peptides which can induce cellular immunity.In this study,we used the three vectors expressing p72,p54,p30 and CD2 v respectively(pCAGGS and NDV)or co-expressing p72 and p54,or p30 and CD2v(VV)to immune.By comparison of ELISPOT outcome of different groups,we found that the strategy that DNA as primary immunization,twice VV as booster immunization can induce cellular immune responses effectively,bringing forth a possibly vaccine candidate against ASF.At the same time,we sequenced SLA-I of experimental pigs and relate it to the outcome of ELISPOT.Weelect a group of peptide which can induce cellular immune responses of pigs of different SLA-I.Our study has made efforts to enhance the cellular immunity to eliminate ASF,getting a group of peptides and vectorswhich has the potential to be vaccine candidates against ASF.