title: Cell wall-associated alpha-glucan is instrumental for Mycobacterium tuberculosis to block CD1 molecule expression and disable the function of dendritic cell derived from infected monocyte.
abstract: We previously described an escape mechanism exploited by Mycobacterium tuberculosis (Mtb) to prevent the generation of fully competent dendritic cells (DC). We have now tested the effect of isolated mycobacterial components on human monocyte differentiation into DC and demonstrated that cell wall (CW)-associated alpha-glucan induces monocytes to differentiate into DC (Glu-MoDC) with the same altered phenotype and functional behaviour of DC derived from Mtb-infected monocytes (Mt-MoDC). In fact, Glu-MoDC lack CD1 molecule expression, fail to upregulate CD80 and produce IL-10 but not IL-12. We also showed that Glu-MoDC are not able to prime effector T cells or present lipid antigens to CD1-restricted T-cell clones. Thus, we propose a mechanism of Mtb-monocyte interaction mediated by CW-associated alpha-glucan, which allows the bacterium to evade both innate and acquired immune responses.
authors: Dipartimento di Malattie Infettive, Parassitarie e Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena 299. 00161, Roma, Italy.
authors: Maria Cristina
authors: MC
authors: Gagliardi
authors: Anne
authors: A
authors: Lemassu
authors: Raffaela
authors: R
authors: Teloni
authors: Sabrina
authors: S
authors: Mariotti
authors: Valeria
authors: V
authors: Sargentini
authors: Manuela
authors: M
authors: Pardini
authors: Mamadou
authors: M
authors: Daffé
authors: Roberto
authors: R
authors: Nisini
mesh_terms: D017951:Antigen Presentation; D018949:Antigens, CD1 / Q000378:metabolism*; D018122:B7-1 Antigen / Q000378:metabolism; D002454:Cell Differentiation; D002473:Cell Wall / Q000378:metabolism*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D005936:Glucans / Q000378:metabolism*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis; D009000:Monocytes / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000378:metabolism / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D018949:Antigens, CD1; D018122:B7-1 Antigen; D005936:Glucans; D016753:Interleukin-10; D018664:Interleukin-12