Ifn γ

Cytokines in the BAL and serum were quantified with enzyme-linked immunosorbent assays (ELISA) following the manufacturer’s instructions of the following kits for the guinea pigs: TNF-α (MBS9303082; MyBioSource, San Diego, CA, USA), IFN-γ (MBS701377; MyBioSource, San Diego, CA, USA), TGF-β1 (CSB-E06773GU; CUSABIO TECHNOLOGY LLC; Houston, TX, USA), IL-1β (MBS765173; MyBioSource, San Diego, CA, USA), 1L-6 (MBS269054; MyBioSource, San Diego, CA, USA) IL-8 (MBS282965; MyBioSource, San Diego, CA, USA), IL-12 (MBS704591; MyBioSource, San Diego, CA, USA).

Fifteen days post-immunization, whole blood obtained from hamsters immunized with rLS1-HN-RBD, rLS1-S1-F, and rLS1-HN-RBD/rLS1-S1-F or allantoic fluid (mock) was centrifuged at 1000×g for 20 min at 4 °C to obtain the serum, which was duly aliquoted, frozen, and stored at − 80 °C until analysis. For the quantitative ELISA, several kits for the accurate quantitative detection of hamster cytokines such as, TNFα, IFNγ, IL-2, IL-4, and IL-10 were purchased from MyBioSource, Inc., San Diego, CA. Cytokine quantifications were performed following the manufacturer's instructions. The plates were read in the EON spectrophotometer (Biotek, USA) at 450 nm. The level of cytokines (pg/mL) detected in the serum of the animals vaccinated with rLS1-HN-RBD, rLS1-S1-F, and rLS1-HN-RBD/rLS1-S1-F were compared with mock vaccinated animals.