The apoptotic-cell receptor CR3, but not alphavbeta5, is a regulator of human dendritic-cell immunostimulatory function.
Dendritic cells (DCs) that capture apoptotic cells (ACs) in the steady state mediate peripheral tolerance to self-antigens. ACs are recognized by an array of receptors on DCs, the redundancy of which is not completely defined. We made use of an AC surrogate system to address the individual roles of the alphavbeta5 and complement receptors (CRs) in the phagocytosis and induction of immunity. CR3 and CR4, while substantially less efficient than alphavbeta5 in internalizing ACs, initiate signals that render DCs tolerogenic. Responding T cells show impaired proliferation and IFNgamma production and subsequently die by apoptosis. While tolerogenic DCs are not induced via alphavbeta5, coligation of CR3 and alphavbeta5 maintains the DC's tolerogenic profile. This immunomodulatory role, however, is countered by a significant inflammatory stimulus such as bacterial infection. Overall, our data suggest that under steady-state conditions, signaling via CRs predominates to render DCs tolerogenic.
Skoberne
Mojca
M
New York University School of Medicine, 550 First Ave, MSB 507, New York, NY 10016, USA.
Somersan
Selin
S
Almodovar
Wanda
W
Truong
Tuan
T
Petrova
Kseniya
K
Henson
Peter M
PM
Bhardwaj
Nina
N
D017209:Apoptosis / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000276:immunology / Q000502:physiology; D016023:Integrins / Q000276:immunology / Q000502:physiology*; D016177:Macrophage-1 Antigen / Q000276:immunology / Q000502:physiology*; D010587:Phagocytosis / Q000276:immunology; D019030:Receptors, Vitronectin / Q000276:immunology / Q000502:physiology*; D017634:Self Tolerance / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D016167:Integrin alphaXbeta2; D016023:Integrins; D016177:Macrophage-1 Antigen; D019030:Receptors, Vitronectin; C064660:integrin alphaVbeta5