Azithromycin, a Lysosomotropic Antibiotic, Has Distinct Effects on Fluid-Phase and Receptor-Mediated Endocytosis, but Does Not Impair Phagocytosis in J774 Macrophages

Study of Macrophage Functions in Murine J774 Cells and Human Activated THP-1 Cells Exposed to Oritavancin, a Lipoglycopeptide with High Cellular Accumulation

“…We demonstrated here an impairment of latex bead phagocytosis in mouse macrophages but no change in fluid phase pinocytosis (in contrast with what has been observed with azithromycin [3]). On the other hand, phagocytosis of bacteria was not impaired in both mouse and human macrophages.…”

“…The bacteria were grown in Mueller-Hinton broth, and CFU counting was performed by plating on tryptic soy agar. Murine J774 (derived from a reticulosarcoma) and human THP-1 (ATCC TIB-202; a myelomonocytic cell line displaying macrophage-like activity) cells were both obtained from the American Tissue Culture Collection (Manassas, VA) and maintained in our laboratory as described previously (3,23) using RPMI 1640 medium supplemented with 10% fetal calf serum (FCS). THP-1 monocytes were differentiated into adherent macrophages (referred to here as A-THP-1 cells) by incubation with phorbol 12-myristate 13-acetate (PMA) (200 g/liter; SigmaAldrich) for 24 h at 37°C.…”

Relationship between Azithromycin Susceptibility and Administration Efficacy for Nontypeable Haemophilus influenzae Respiratory Infection

“…First, AZM is a lysosomotropic antibiotic, whose accumulation is associated with a vacuolation of endosomes in macrophages and fibroblasts (59,60). Our immunofluorescence-based analysis did not reveal significant differences in the percentage of NTHI-EEA1/LAMP1 colocalization in A549 cells, limiting a possible AZM-triggered modulation of NTHI's intracellular location.…”

Low Density Lipoprotein Receptor-related Protein Mediates Endocytic Clearance of Pro-MMP-2·TIMP-2 Complex through a Thrombospondin-independent Mechanism

“…The endocytic rate (ϳ0.6%.min Ϫ1 ; Fig. 3, top panel) is rather slow for receptormediated endocytosis (typically reaching ϳ10%.min Ϫ1 for transferrin and up to ϳ30%.min Ϫ1 for occupied growth factor receptors) (42), but this value is comparable to those previously found for other LRP ligands, such as TSP (22), uPA (43), and MMP-13 (18). Intracellular 125 I-pro-MMP-2⅐TIMP-2 complex leveled off after 1 h (Fig.…”