Pulmonary surfactant-biomimetic nanoparticles potentiate heterosubtypic influenza immunity

Current influenza vaccines only confer protection against homologous viruses. We synthesized pulmonary surfactant (PS)–biomimetic liposomes encapsulating 2',3'-cyclic guanosine monophosphate–adenosine monophosphate (cGAMP), an agonist of the interferon gene inducer STING (stimulator of interferon genes). The adjuvant (PS-GAMP) vigorously augmented influenza vaccine–induced humoral and CD8+ T cell immune responses in mice by simulating the early phase of viral infection without concomitant excess inflammation. Two days after intranasal immunization with PS-GAMP–adjuvanted H1N1 vaccine, strong cross-protection was elicited against distant H1N1 and heterosubtypic H3N2, H5N1, and H7N9 viruses for at least 6 months while maintaining lung-resident memory CD8+ T cells. Adjuvanticity was then validated in ferrets. When alveolar epithelial cells (AECs) lacked Sting or gap junctions were blocked, PS-GAMP–mediated adjuvanticity was substantially abrogated in vivo. Thus, AECs play a pivotal role in configuring heterosubtypic immunity.

Source: ScienceNOW - February 19, 2020 Category: Science Authors: Wang, J., Li, P., Yu, Y., Fu, Y., Jiang, H., Lu, M., Sun, Z., Jiang, S., Lu, L., Wu, M. X. Tags: Immunology, Microbiology, Online Only r-articles Source Type: news