# Candida albicans releases a peptide from the Rbt1 protein to promote its invasion into the gut epithelium

## TL;DR

The fungus Candida albicans releases a peptide from the Rbt1 protein to weaken gut cell barriers, promoting infection.

## Contribution

This is the first study to show a fungal peptide directly disrupts gut epithelial barriers to aid infection.

## Key findings

- Candida albicans releases a peptide from Rbt1 during early infection.
- The peptide disrupts tight junctions in intestinal cells by downregulating ZO-1.
- This mechanism promotes fungal invasion into the gut epithelium.

## Abstract

Candida albicans has been recently added to the WHO critical priority group of fungal pathogens based on its impact on global public health. C. albicans is a mucosal commensal yeast in humans that can cause severe gastrointestinal-borne disseminated candidiasis in immunocompromised patients. C. albicans interaction with enterocytes is thus a key step in the pathophysiology of disseminated candidiasis. Here, we show that, during the first steps of the infection process, C. albicans releases a peptide from the Repressed by Tup1 protein 1 (Rbt1), which disorganizes the cell‒cell adhesion junctions in Caco-2 intestinal epithelial cells by notably downregulating constitutive proteins of the tight junction complex (i.e. ZO-1). This is the first report to show that a peptide of a human pathogenic fungus promotes fungal invasion into the gut epithelium by disorganizing the protective epithelial barrier.