CD4+ Th-APC with acquired peptide/MHC class I and II complexes stimulate type 1 helper CD4+ and central memory CD8+ T cell responses.

CD8+ cytotoxic T-APC stimulate central memory CD8+ T cell responses via acquired peptide-MHC class I complexes and CD80 costimulation, and IL-2 secretion.

We previously showed that naive CD4+ Th cells acquire peptide-MHC class I (pMHC I) and costimulatory molecules from OVA-pulsed dendritic cells (DC(OVA)), and act as Th-APCs in stimulation of CD8+ CTL responses. In this study, we further demonstrated that naive CD8+ cytotoxic T (Tc) cells also acquire pMHC I and costimulatory CD54 and CD80 molecules by DC(OVA) stimulation, and act as Tc-APC. The...

A new dynamic model of CD8+ T effector cell responses via CD4+ T helper-antigen-presenting cells.

A long-standing paradox in cellular immunology has been the conditional requirement for CD4(+) Th cells in priming of CD8(+) CTL responses. We propose a new dynamic model of CD4(+) Th cells in priming of Th-dependent CD8(+) CTL responses. We demonstrate that OT II CD4(+) T cells activated by OVA-pulsed dendritic cells (DC(OVA)) are Th1 phenotype. They acquire the immune synapse-composed MHC II/...

Responses T + and Central Memory CD 8 + Helper CD 4 Class I and II Complexes Stimulate Type 1 Th - APC with Acquired Peptide / MHC + CD 4

Novel exosome-targeted CD4+ T cell vaccine counteracting CD4+25+ regulatory T cell-mediated immune suppression and stimulating efficient central memory CD8+ CTL responses.

T cell-to-T cell Ag presentation is increasingly attracting attention. In this study, we demonstrated that active CD4+ T (aT) cells with uptake of OVA-pulsed dendritic cell-derived exosome (EXO(OVA)) express exosomal peptide/MHC class I and costimulatory molecules. These EXO(OVA)-uptaken (targeted) CD4+ aT cells can stimulate CD8+ T cell proliferation and differentiation into central memory CD8...

Presentation of acquired peptide-MHC class II ligands by CD4+ regulatory T cells or helper cells differentially regulates antigen-specific CD4+ T cell response.

Activated T cells can acquire membrane molecules from APCs through a process termed trogocytosis. The functional consequence of this event has been a subject of debate. Focusing on transfer of peptide-MHC class II (MHC-II) complexes from APCs to CD4(+) T cells after activation, in this study we investigated the molecule acquisition potential of naturally occurring regulatory T cells (Tregs) and...