Deciphering cytokine Dynamics: Staged immune responses in acute otitis media

Acute otitis media (AOM) is highly prevalent among preschool children and can lead to chronic otitis media or severe complications if untreated. The pathogenesis of AOM is closely tied to the host's immune response, yet the expression profile of cytokines, which mediate these responses, remains poorly defined.

This study aims to identify cytokines involved in AOM immune responses and to elucidate their roles at different stages of the disease.

We induced AOM in mice by injecting nontypeable Haemophilus influenzae (NTHi) through the tympanic membrane. Middle ear tissues were collected for analysis. PCR Array and Protein Array identified cytokines at 6 and 12 hours (h) post-infection. qPCR and Luminex multiplex detection technology were then used to track cytokine expression at various key time points, allowing us to speculate on their roles in the immune process.

PCR Array identified 13 cytokines with significant mRNA differences at 6 h. Protein Array identified 9 differentially expressed cytokines at 12 h qPCR tracked mRNA expression at key time points (6 h, 12 h, 1day (d), 2 d, 3 d and 7 d), revealing a total of 20 cytokines. Luminex detected 31 cytokines at key time points (12 h 1 d, 2 d and 5 d), 10 of which were previously mentioned. Cytokines were classified into three distinct categories according to their expression trends: early-phase (n = 13), progressive-phase (n = 20), and terminal-phase (n = 4) cytokines.

Cytokines play distinct and crucial roles at each stage of AOM, with potential interactions among those highly expressed in the same stage.