RT Journal Article SR Electronic(1) A1 Morey, Pau A1 Cano, Victoria A1 Martí-Lliteras, Pau A1 López-Gómez, Antonio A1 Regueiro, Verónica A1 Saus, Carles A1 Bengoechea, José Antonio A1 Garmendia, JunkalYR 2011 T1 Evidence for a non-replicative intracellular stage of nontypable Haemophilus influenzae in epithelial cells JF Microbiology, VO 157 IS 1 SP 234 OP 250 DO https://doi.org/10.1099/mic.0.040451-0 PB Microbiology Society, SN 1465-2080, AB Nontypable Haemophilus influenzae (NTHi) is a Gram-negative, non-capsulated human bacterial pathogen, a major cause of a repertoire of respiratory infections, and intimately associated with persistent lung bacterial colonization in patients suffering from chronic obstructive pulmonary disease (COPD). Despite its medical relevance, relatively little is known about its mechanisms of pathogenicity. In this study, we found that NTHi invades the airway epithelium by a distinct mechanism, requiring microtubule assembly, lipid rafts integrity, and activation of phosphatidylinositol 3-kinase (PI3K) signalling. We found that the majority of intracellular bacteria are located inside an acidic subcellular compartment, in a metabolically active and non-proliferative state. This NTHi-containing vacuole (NTHi-CV) is endowed with late endosome features, co-localizing with LysoTracker, lamp-1, lamp-2, CD63 and Rab7. The NTHi-CV does not acquire Golgi- or autophagy-related markers. These observations were extended to immortalized and primary human airway epithelial cells. By using NTHi clinical isolates expressing different amounts of phosphocholine (PCho), a major modification of NTHi lipooligosaccharide, on their surfaces, and an isogenic lic1BC mutant strain lacking PCho, we showed that PCho is not responsible for NTHi intracellular location. In sum, this study indicates that NTHi can survive inside airway epithelial cells., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.040451-0