The eye is an immune privileged tissue with multiple mechanisms of immunosuppression to protect the light gathering tissues from the damage of inflammation. One of theses mechanisms involves retinal pigment epithelial cell suppression of phagosome activation in macrophages. The objective of this work is to determine if the human RPE cell line ARPE-19 is capable of suppressing the activation of ...

The replication of Tropheryma whipplei (the agent of Whipple's disease) within human macrophages is associated with the expression of IL-16, a cytokine known for its chemotactic and inflammatory properties. In this study, we asked whether IL-16 acts on T. whipplei replication by interfering with the endocytic pathway. We observed that in macrophages, T. whipplei was located within late phagosom...

Yeast cells of the human pathogen Candida albicans that enter the bloodstream can be engulfed by macrophage cells but survive in, and can escape from, the phagolysosome. The C. albicans gene HGT12, which is specifically expressed during macrophage infection, encodes a protein that transports fructose, glucose and mannose. Expression of this hexose transporter along with the shift from glycolysi...

To investigate the function of alveolar macrophages (AM) and the mechanisms of impairment in pulmonary alveolar proteinosis, we established in culture AM from three patients and from eight normal nonsmokers and assessed phagocytosis and phagolysosome fusion by the acridine orange assay with live yeast as the phagocytic challenge. Alveolar macrophages from the patients with pulmonary alveolar pr...

UNLABELLED Group A Streptococcus (GAS, Streptococcus pyogenes) is an ongoing threat to human health as the agent of streptococcal pharyngitis, skin and soft tissue infections, and life-threatening conditions such as necrotizing fasciitis and streptococcal toxic shock syndrome. In animal models of infection, macrophages have been shown to contribute to host defense against GAS infection. However...

Receptors for the Fc domain of IgG mediate target recognition, signal transduction, and effector functions including antibody-dependent cytolysis, phagocytosis, and phagolysosome formation. To better understand FcR-mediated functions and to identify potential therapeutic strategies, we employed cell-penetrating ("Trojan") peptides to deliver "wild-type" (LTL) or modified (AAA) FcgammaRIIA tail ...