Humoral response to the central unglycosylated region of the respiratory syncytial virus attachment protein

To characterize the humoral response to the unglycosylated central region of the respiratory syncytial virus (RSV) attachment (G) protein, we generated glutathione S-transferase (GST)–RSV G subdomains (central core (CC), residues 151–190; proximal central core (PCC), 151–172; and distal central core (DCC), 173–190) to screen paired sera from RSV subtype A- or B-infected adults in hospitalized or outpatient settings. Following RSV infection, a ≥4-fold increase in homo- and heterosubtypic IgG response was noted in most subjects against the RSV G CC and PCC regions; in contrast, such titer increases against the RSV G DCC was only noted in a homosubtypic manner. Our results have implications for RSV G-based serological diagnostics and vaccine development.