The Extra Domain A from Fibronectin Targets Antigens to TLR4-Expressing Cells and Induces Cytotoxic T Cell Responses In Vivo

• Published in: Journal of Immunology 2007-01, Vol.178 (2), p.748-756
• Main Authors: Lasarte, Juan J, Casares, Noelia, Gorraiz, Marta, Hervas-Stubbs, Sandra, Arribillaga, Laura, Mansilla, Cristina, Durantez, Maika, Llopiz, Diana, Sarobe, Pablo, Borras-Cuesta, Francisco, Prieto, Jesus, Leclerc, Claude
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Animals; Bone Marrow - metabolism; Cell Differentiation; Cells, Cultured; Dendritic Cells - cytology; Dendritic Cells - metabolism; Female; Fibronectins - chemistry; Fibronectins - genetics; Fibronectins - metabolism; Humans; Interleukin-12 - biosynthesis; Mice; Mice, Inbred C57BL; Mice, Knockout; Neoplasms - immunology; Neoplasms - metabolism; Neoplasms - pathology; Ovalbumin - immunology; Peptide Fragments - chemistry; Peptide Fragments - genetics; Peptide Fragments - metabolism; Protein Binding; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Signal Transduction; T-Lymphocytes, Cytotoxic - immunology; T-Lymphocytes, Cytotoxic - metabolism; Toll-Like Receptor 4 - deficiency; Toll-Like Receptor 4 - genetics; Toll-Like Receptor 4 - metabolism; Tumor Necrosis Factor-alpha - biosynthesis
• ISSN: 0022-1767; 1550-6606; 1365-2567
• DOI: 10.4049/jimmunol.178.2.748

Vaccination strategies based on the in vivo targeting of Ags to dendritic cells (DCs) are needed to improve the induction of specific T cell immunity against tumors and infectious agents. In this study, we have used a recombinant protein encompassing the extra domain A from fibronectin (EDA), an endogenous ligand for TLR4, to deliver Ags to TLR4-expressing DC. The purified EDA protein was shown to bind to TLR4-expressing HEK293 cells and to activate the TLR4 signaling pathway. EDA also stimulated the production by DC of proinflammatory cytokines such as IL-12 or TNF-alpha and induced their maturation in vitro and in vivo. A fusion protein between EDA and a cytotoxic T cell epitope from OVA efficiently presented this epitope to specific T cells and induced the in vivo activation of a strong and specific CTL response. Moreover, a fusion protein containing EDA and the full OVA also improved OVA presentation by DC and induced CTL responses in vivo. These EDA recombinant proteins protected mice from a challenge with tumor cells expressing OVA. These results strongly suggest that the fibronectin extra domain A may serve as a suitable Ag carrier for the development of antiviral or antitumoral vaccines.