Involvement of Stat1 in the Phagocytosis of M. avium. (28th June 2012)

• Record Type: Journal Article
• Authors: Dominici, Sabrina; Schiavano, Giuditta Fiorella; Magnani, Mauro; Buondelmonte, Costantina; Celeste, Angela Gabriela; Brandi, Giorgio
• Other Names: Maggi Enrico Academic Editor.
• Is Part Of: Clinical & developmental immunology. Volume 2012(2012)
• Publication Date: 2012-06-28
• Subjects: Developmental immunology -- Periodicals; Clinical immunology -- Periodicals; Immune System -- immunology -- Periodicals; Immune System -- growth & development -- Periodicals; Immune System Diseases -- immunology -- Periodicals; 571.9638
• DOI: 10.1155/2012/652683
• Languages: English
• ISSNs: 1740-2522

Abstract

Abstract : Mycobacterium avium is an intracellular pathogen preferentially infecting human macrophages where they activate the JAK/STAT1 pathway. This activation enhances the survival of infected cells, but, at the same time, makes macrophages optimal targets for drugs development against p-tyr701 stat1. In this study, we demonstrate that the fast and transient activity of the JAK/STAT1 pathway occurs immediately after macrophages internalization of heat-killed M. avium or inert particles. Furthermore, we show that a persistent Stat1 pathway activation occurs only when an intracellular M. avium infection is established in macrophages. These results strongly indicate different mechanisms of p-tyr701 Stat1 activation. In particular, here we report findings aiming at explaining the short-time enhancement of p-tyr701 Stat1 and shows its predominant relationship with Fc γ Rs engagement during the internalization process. Furthermore, we demonstrate that opsonized live M. avium is phagocytosed by macrophages involving membrane receptors not related with JAK/STAT1 signalling pathway. On the contrary, heat-inactivated bacilli or latex particles seem to be internalized only after involvement of Fc γ Rs and subsequent Stat1 phosphorylation.