Van Andel Institute researchers reveal how Legionella bacteria manipulate host cells

Scientists at the Van Andel Institute have discovered how Legionella bacteria manipulate host cells to survive and multiply. The research, published in the Proceedings of the National Academy of Sciences, focuses on a bacterial protein called RomA.

Rather than breaking into healthy cells, Legionella uses RomA to mimic the behavior of the host cell’s own proteins. This allows the bacteria to alter gene regulation within the host, specifically targeting immune cells known as macrophages to create a refuge for the pathogen.

However, the study reveals a biological trade-off: while RomA can exploit the host’s epigenetic machinery, it is also constrained by the host cell’s existing epigenetic landscape. This interaction creates a two-way conversation where the host’s own biological rules act as guardrails, limiting what the pathogen can achieve. Researchers suggest these insights into the nuanced interaction between host and pathogen could lead to new therapeutic strategies for treating Legionnaires' disease.