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bioRxiv · 10.64898/2026.05.18.725648

Streptococcal superantigen SpeC induces IL-8 secretion in human epithelial cells

Zhang, X.·Na, R.·Guo, S.
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Abstract

Streptococcal pyrogenic exotoxin C (SpeC) is a prototypical superantigen produced by group A Streptococcus. It potently activates a broad subset of T lymphocytes via a bridging interaction involving TCR{beta}-SpeC-MHC-II. Our recent work demonstrated that SpeC induced profound release of IL-8 from human pharyngeal epithelial cells and this effect was reversible through a specific point mutation in SpeC. This study systematically investigated cellular signaling pathways using integrated transcriptomic profiling and Western blot analysis, with a focus on membrane-associated receptors and downstream intracellular signaling effectors. Our results demonstrate that this biological process is critically associated with the activation of Erk1/2, p38 MAPK and NF-{kappa}B signaling cascade. This study identifies a novel mechanism through which a bacterial superantigen target epithelial cells-the body primary physical barrier and first line of innate immune defense.

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Zhang, X., Na, R., Guo, S.. 2026-05-18. Streptococcal superantigen SpeC induces IL-8 secretion in human epithelial cells. https://doi.org/10.64898/2026.05.18.725648

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