Hantaan virus induces heat-shock protein 70 expression in brain of suckling mice and its correlation with viral proteins / 中华传染病杂志

ABSTRACT

Objective To study the impact of viral infection on stress protein gene expression and investigate the possibility that heat shock proteins interact with viral components during viral assembly in the brain of suckling mice experimentally infected with Hantaan virus (HV). Methods New born mice less than 72 h of age were inoculated into brain with the 100 LD50 of Hantaan virus (strain 76 118). At the 8th day mice died from brain disease. Brains were prepared for tissue sections and extracts for the experiments. The Hantaan virus infection, HSP70 induction and their co localization in brain of infected suckling mice were demonstrated by immunohistochemical staining and laser scan co focal microscopic double labling. The possible intereaction between HV structural proteins and HSP70 was further analyzed by immunoprecipitation of infected tissue extracts with antibodies to either HSP70 or to viral nuclear capsule proteins HV NP by using SDS PAGE and Western blotting. Results HV infection induced an increased levels of HSP70 expression at the cytoplasma of neurons in the brain of suckling mice HV NP protein proved to be co localized with HSP70. Monoclonal antibody (mAb) to HSP70 could co immunoprecipitate the HV NP, and similarly mAb to HV NP could co immunoprecipitate HSP70 from virus infected tissue extracts, but not from mock infected tissue extracts. Antibody, which recognized one of these two proteins, did not cross react with the other. Thus, the association between HSP70 and HV NP appeared to be specific.Conclusions Hantavirus infection can directly induce HSP70 expression, leading to the formation of HV HSP 70 viral antigen peptide complex which plays some roles in the course of viral infection and replication.