The response of nasal epithelial cells exposed to novel Lactobacillus and alpha-haemolytic Streptococcus isolated from the upper respiratory tract of children.

Abstract

Aims: To investigate the response of primary nasal epithelial cells (NECs) to novel alpha haemolytic Streptococcus and lactobacilli strains, isolated from the upper respiratory tract of children.

Methods and results: Submerged cultures of NECs from healthy adult donors were exposed to either novel strains; Lactobacillus rhamnosus D3189, D3160, Streptococcus salivarius D3837; or commercially available probiotic strains L. rhamnosus LB21, S. salivarius K12; or a pathogenic strain (S. pneumoniae 49 619). Cytotoxicity (measured through lactate dehydrogenase release) and cytokine release were quantified 24 hours post-exposure. Exposure to novel and commercially available strains did not induce the production of IFN-β, IFN-λ1/3, IL-1β, IL-6, IL-8 or TNF-α production or the release of LDH. Conversely, the pathogenic strain S. pneumoniae 49 619 significantly elevated the expression of IL-1β, IL-8, TNF-α, and LDH in NECs.

Conclusions: The findings within this study highlight the non-pathogenic nature of these novel strains and support further investigation of the potential to develop nasally administered probiotics.