Signal-induced alternative pre-mrna splicing in the TLR signaling pathway

The National Institute of Allergy and Infectious Diseases, part of the Department of Health and Human Services National Institutes of Health, awarded National Jewish Health $261,615 on September 1, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855).

The project examines signal-induced alternative pre-mRNA splicing in the toll-like receptor (TLR) signaling pathway to identify how RNA binding proteins SRSF1 and HNRNPU regulate LPS-induced alternative splicing that produces dominant negative inhibitors of TLR signaling. The research aims to determine how SRSF1 and HNRNPU coordinate alternative splicing to enable efficient termination of inflammation and prevent chronic inflammatory disease while preserving the initial anti-pathogen response. The work tests the hypothesis that pathogen components such as lipopolysaccharide induce production of alternative splice forms that constitute a negative feedback loop preventing persistent TLR signaling.

Performance runs through August 31, 2028, at National Jewish Health in Denver, Colorado. The assistance type is a Project Grant.

Abstract

In the presence of pathogens, the TLR signaling pathway is activated and induces inflammation to fight infection. However, persistent TLR signaling can lead to chronic inflammation and resulting inflammatory disease. One mechanism that limits persistent TLR signaling is production of alternative splice forms in the TLR signaling pathway. Pathogen components such as lipopolysaccharide (LPS) induce the production of alternative splice forms that encode dominant negative inhibitors of TLR signaling. Thus, production of these negatively acting mrna splice forms constitutes a negative feedback loop that prevents chronic inflammation. Our preliminary studies have identified the RNA binding proteins SRSF1 and hnrnpu as CIS-acting regulators of LPS-induced alternative splicing of the key TLR pathway signaling adaptor MYD88. Moreover, our preliminary studies indicate that these same RNA binding proteins likely regulate splicing of other genes in the TLR signaling pathway. We hypothesize that SRSF1 and hnrnpu coordinate LPS-induced alternative splicing in the TLR signaling pathway to enable efficient termination of inflammation. In the current proposal, we will (1) determine how SRSF1 and hnrnpu regulate alternative splicing in the TLR signaling pathway and (2) determine how LPS regulates the activity of SRSF1 and hnrnpu. These studies represent a critical step towards our goal of harnessing this alternative splicing mechanism to prevent persistent inflammation and resulting inflammatory disease without ablating the necessary initial anti-pathogen response.