Heat-Shock Protein 70 Enhances The Specific Immune Response Elicited By Hantaan Virus Nucleocapsid Protein And S Segment

Heat-shock protein 70 (HSP70), a member of HSPs family, is a highly conserved chaperone protein involved in protein assembling, folding, transportation and antigen processing and presenting. The increased expression of HSP70 can be found in various stressful conditions including Hantavirus (HV) infection in our previous research. HV are rodent-borne, enveloped RNA viruses in the family Bunyaviridae. It contains a tri-segmented, negative-sense, single-stranded RNA genome that is divided into three segments: the large (L), medium (M), and small (S). The S segment encodes a nucleocapsid (NP); the M segment encodes two envelope glycoproteins (G1 and G2); and L segment encodes a viral RNA polymerase protein. It has been demonstrated that Gland G2 proteins contain virus-neutralizing epitopes while NP proteins contains antigenic sites associated with cytotoxic T-lymphocyte (CTL) responses. Our previous study showed that HSP70 forms complexes with HTNV NP in HTNV infected Vero E6 cell and mice brain. A growing number of studies suggested that HSP70 can play as a molecule carrier and enhances the antigenicity of its associated proteins, and this molecular adjuvant feature made HSPs be an attractive immunostimulating components for development of subunit vaccines, however, there is still no report about HSP70 fused HTNV NP vaccine so far.