Wallington JC, et al. – The mechanisms behind conventional T and mucosal-associated invariant T (MAIT) cell cytotoxic responses to nontypeable Haemophilus influenzae (NTHi) were explored. MAIT cells had a cytotoxic role in the lung. Results highlighted important differences in the control of adaptive and innate-like T cell responses. In order to modulate the anti-bacterial response and improve clinical outcome, understanding these mechanisms could lead to new therapeutic opportunities.