Intranasal immunization with plasmid DNA encoding spike protein of SARS-coronavirus/polyethylenimine nanoparticles elicits antigen-specific humoral and cellular immune responses

• Main Authors: Yang Moon-Sik, Jang Yong-Suk, Kim Dong, Song Man, Chu Hyuk, Jere Dhananjay, Quan Ji-Shan, Park Sung-Moo, Shim Byoung-Shik, Han Seung, Park Yong-Ho, Cho Chong-Su, Yun Cheol-Heui
• Format: Article
• Language: English
• Published: BMC 2010-12-01
• Series: BMC Immunology
• Online Access: http://www.biomedcentral.com/1471-2172/11/65

<p>Abstract</p> <p>Background</p> <p>Immunization with the spike protein (S) of severe acute respiratory syndrome (SARS)-coronavirus (CoV) in mice is known to produce neutralizing antibodies and to prevent the infection caused by SARS-CoV. Polyethylenimine 25K (PEI) is a cationic polymer which effectively delivers the plasmid DNA.</p> <p>Results</p> <p>In the present study, the immune responses of BALB/c mice immunized via intranasal (i.n.) route with SARS DNA vaccine (pci-S) in a PEI/pci-S complex form have been examined. The size of the PEI/pci-S nanoparticles appeared to be around 194.7 ± 99.3 nm, and the expression of the S mRNA and protein was confirmed <it>in vitro</it>. The mice immunized with i.n. PEI/pci-S nanoparticles produced significantly (<it>P </it>< 0.05) higher S-specific IgG1 in the sera and mucosal secretory IgA in the lung wash than those in mice treated with pci-S alone. Compared to those in mice challenged with pci-S alone, the number of B220⁺cells found in PEI/pci-S vaccinated mice was elevated. Co-stimulatory molecules (CD80 and CD86) and class II major histocompatibility complex molecules (I-A^d) were increased on CD11c⁺dendritic cells in cervical lymph node from the mice after PEI/pci-S vaccination. The percentage of IFN-γ-, TNF-α- and IL-2-producing cells were higher in PEI/pci-S vaccinated mice than in control mice.</p> <p>Conclusion</p> <p>These results showed that intranasal immunization with PEI/pci-S nanoparticles induce antigen specific humoral and cellular immune responses.</p>