C1q-Dependent Dendritic Cell Cross-Presentation of In Vivo-Formed Antigen-Antibody Complexes

• Published in: The Journal of immunology (1950) Vol. 198; no. 11; pp. 4235 - 4243
• Main Authors: Ho, Nataschja I, Camps, Marcel G M, de Haas, Edwin F E, Trouw, Leendert A, Verbeek, J Sjef, Ossendorp, Ferry
• Format: Journal Article
• Language: English
• Published: United States American Association of Immunologists 01.06.2017
• Subjects: Adaptive Immunity; Animals; Antigen Presentation; Antigen-Antibody Complex - immunology; Antigen-presenting cells; CD8 Antigens - immunology; Cell surface; Complement C1q - deficiency; Complement C1q - genetics; Complement C1q - immunology; Complement component C1q; Cross-Priming; Dendritic cells; Dendritic Cells - immunology; Lymphocytes; Lymphocytes T; Mice; Mice, Inbred C57BL; Receptors, IgG - immunology; Spleen
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1602169

Dendritic cells (DCs) are specialized in Ag engulfment via a wide variety of uptake receptors on their cell surface. In the present study we investigated Ag uptake and presentation of in vivo-formed Ag-Ab complexes by i.v. injecting mice with Ag-specific Abs followed by the cognate Ag. We show by this natural Ab-mediated Ag targeting system that uptake by splenic APC subsets is severely hampered in mice lacking complement factor C1q (C1qa ). Moreover, no detectable Ag cross-presentation by CD8α DCs from C1qa mice was found. On the contrary, Ag uptake was not hampered by APCs in FcγRI/II/III/IV-deficient (FcγR quadruple ) mice, and the cross-presentation ability of CD8α DCs was not affected. In conclusion, we show that C1q rather than FcγRs controls the Ab-mediated Ag uptake and its presentation by spleen APC subsets to T cells.