Protein D expression promotes the adherence and internalization of non-typeable Haemophilus influenzae into human monocytic cells

TheMoraxella catarrhalisImmunoglobulin D-Binding Protein MID Has Conserved Sequences and Is Regulated by a Mechanism Corresponding to Phase Variation

“…To obtain the maximal proliferative response, the T-helper (Th) cytokines IL-2 and IL-4 are required, whereas the Th2-specific cytokines IL-4 and IL-10 are needed for optimal IgA and IgG production. Protein D from H. influenzae is another IgD-binding OMP that we have characterized, and it has been shown to be an important pathogenicity factor (3,25). However, protein D does not bind to the majority of IgD myelomas tested, and it has been proposed that encapsulated H. influenzae serotype b expresses an additional IgD receptor (47).…”

Mammalian Glycerophosphodiester Phosphodiesterases

“…[3][4][5] In a rat otitis model, a GlpQ mutant required an approximately 100 fold-higher inoculum than the parental H. influenzae in order to induce otitis media after injection, strongly suggesting that GlpQ plays an important role as a virulence factor in H. influenzae. 6,7) Recently, a novel physiological role of H. influenzae GlpQ, closely related to the adherence of bacteria to human cells, was proposed. H. influenzae incorporates choline obtained from abundant pools of degradation products of the host cell membrane lipid by using GlpQ in its lipopolysaccaride as phosphorylcholine, which contributes to the pathogenesis by mimicry of the host cell membrane.…”

“…H. influenzae incorporates choline obtained from abundant pools of degradation products of the host cell membrane lipid by using GlpQ in its lipopolysaccaride as phosphorylcholine, which contributes to the pathogenesis by mimicry of the host cell membrane. 6) E. coli GlpQ is a periplasmic protein, whereas this enzyme of H. influenzae is a lipoprotein located in the outer membrane, suggesting that the difference in the cellular location of these bacterial GP-PDEs might provide functional diversity among these enzymes.…”

Nontypeable Haemophilus influenzae Carbonic Anhydrase Is Important for Environmental and Intracellular Survival

“…We observed a 30 to 60% reduction in intracellular survival for the NTHi 86-028NP ⌬can mutant in the monocytic cell line THP-1. Although NTHi is not a typical intracellular pathogen, various studies report that NTHi is able to invade adenoid tissue (44), mouse J774 macrophages (45), and the human monocyte cell lines U937 and THP-1 (46). We show that lysosome-phagosome fusion, which results in acidification of the phagosome, plays a role in increased killing of the NTHi 86-028NP ⌬can mutant in THP-1 cells.…”