Joseph E. Kerschner

Objectives 17β‐estradiol (E2) is a steroidal hormone with immunomodulatory functions that play a role in infectious and inflammatory diseases. E2 was recently identified as the leading upstream regulator of differentially expressed genes in a comparative RNA sequencing study of pediatric patients with otitis media (OM) versus OM‐free counterparts and may therefore play a role in the inflammatory response to bacterial otopathogens during pediatric OM. This study examined the effect of E2 on bacterial‐induced inflammatory cytokine expression in an in vitro pediatric OM model. Methods An immortalized middle ear (ME) epithelial cell line, ROM‐SV40, was developed from a pediatric recurrent OM patient. The culture was exposed to E2 at physiological levels for 1–48 h prior to 6 h‐stimulation with nontypeable Haemophilus influenzae (NTHi) whole cell lysate. TNFA , IL1B , IL6 , and IL8 were assayed by qPCR and ELISA. Results E2 pretreatment (24 h) abrogated NTHi induction of IL6 ; a longer pretreatment (1–10 nM, 48 h) abrogated IL1B induction ( p < 0.05). E2 pretreatment (5 nM, 48 h) abrogated NTHi‐induced IL8 secretion ( p = 0.017). Conclusion E2 pretreatment partially rescued NTHi‐induced cytokine production by ME epithelia. These data support a role for E2 in moderating the excessive inflammatory response to middle ear infection that contributes to OM pathophysiology. Levels of Evidence NA Laryngoscope , 2024