Conventional CD4+ T cells present bacterial antigens to induce cytotoxic and memory CD8+ T cell responses. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Cruz-Adalia, Aránzazu; Ramirez-Santiago, Guillermo; Osuna-Pérez, Jesús; Torres-Torresano, Mónica; Zorita, Virgina; Martínez-Riaño, Ana; Boccasavia, Viola; Borroto, Aldo; Martínez del Hoyo, Gloria; González-Granado, José; Alarcón, Balbino; Sánchez-Madrid, Francisco; Veiga, Esteban
• Is Part Of: Nature communications. Volume 8:Issue 1(2017)
• Page Start: 1
• Page End: 11
• Publication Date: 2017-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-017-01661-7
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract Bacterial phagocytosis and antigen cross-presentation to activate CD8+ T cells are principal functions of professional antigen presenting cells. However, conventional CD4+ T cells also capture and kill bacteria from infected dendritic cells in a process termed transphagocytosis (also known as transinfection). Here, we show that transphagocytic T cells present bacterial antigens to naive CD8+ T cells, which proliferate and become cytotoxic in response. CD4+ T-cell-mediated antigen presentation also occurs in vivo in the course of infection, and induces the generation of central memory CD8+ T cells with low PD-1 expression. Moreover, transphagocytic CD4+ T cells induce protective anti-tumour immune responses by priming CD8+ T cells, highlighting the potential of CD4+ T cells as a tool for cancer immunotherapy. Antigen presentation is generally considered the domain of innate immune cells, but CD4+ T cells can transphagocytose bacteria from infected dendritic cells. Here the authors show CD4+ T cells can transphagocytose bacterial and tumour antigens and present them to CD8+ T cells to activate memory and cytotoxic functions.