Detection Of Human Cytomegalovirus(HCMV)-glycoprotein B(gB)-specific Cytotoxic T Lymphocytes(CTLs) In Bone Marrow Transplantation (BMT) Recipients

BackgroundHuman cytomegalovirus(HCMV) is one of the most important causes of graft failure、morbidity and mortality in bone marrow transplantation recipients. HCMV as intracellular infection, the clearance of the disease and complication caused by HCMV in the virus carrier depand on the celler immune responses.HCMV glycoprotein B (gB) coded by HCMV gene is one of the most immunogenicity protein.Detection of HCMV gB-specific CTLs in BMT recipients may have an relevance value against HCMV infection.Methods and Objectives16recipients treated BMT in our hospital from2009.2-2010.10,9HLA-A*0201restricted recipients,7HLA-A*1101restricted recipients and8health examination persons were enrolled,totally224samples of whole blood were collected. pp65antigenemia were measured by immunocytochemical staining and IFN-γ、IL-6levels were detected by enzyme-linked immunosorbent assays(ELISA) at8and12weeks after BMT; The results of the strength of the HLA-gB-specific CTLs detected with FACs using Proimmune Pro5Pentamers were investigated to assess the true gB epoitope.The correlation between the strength of HLA-gB-specific CTLs and IFN-γ、 IL-6levels were analysed, advancing our understanding of HCMV gB-specific CTLs immune response in BMT recipients.Results1. In HLA-A*0201group,the IFN-γ、IL-6levels were12.43±7.60pg/ml and282.41±149.28pg/ml respectively;In HLA-A*1101group.the the IFN-γ、IL-6levels were16.36±6.55pg/ml、247.59±102.63pg/ml respectively; No difference of the IFN-γ、 IL-6levels was observed between the two groups(P>0.05);2. In HLA-A*0201group,no difference was observed among the strength of the seven gB-specific CTLs (P>0.05);In HLA-A*1101group,the strength of HCMV gB527-535(AILSAIYNK)-specific CTLs was1.26±0.86%,higher than that of the other nine gB peptides,the difference reached the statistical significance (P<0.05)3. pp65antigenemia had a negative correlation with the strength of the HLA-gB-specific CTLs (P=0.003) and the HLA-A*1101～gB-specific CTLs(P=0.04), No obvious relationship was analysed between pp65antigenemia and the strength of the HLA-A*0201～gB-specific CTLs(P=0.209);The strength of the HLA～gB-specific CTLs had a negative relationship with IFN-y levels (P=0.022) and a positive linear relationship with IL-6levels in PBLs (P=0.005).Conclusions1. Establish a immunoassay technology of the MHC restricted HCMV glycoprotein B (gB)-specific CTLs;2. In the total23gB peptides enrolled in our study,the HLA-A*1101～gB527-535(AELSAIYNK) was assessed as the true gB epoitope; 3. HCMV gB-specific CTLs may exert their inhibitory action against HCMV pp65antigenemia; IL-6may induce the expression of the HCMV gB-specific CTLs.