CD11c participates in triggering acute graft-versus-host disease during bone marrow transplantation

Area of Science:

• Immunology
• Cell Biology

Background:

• CD11c is a known marker for dendritic cells (DCs), but its precise functions in the immune system remain unclear.
• Acute graft-versus-host disease (aGVHD) is a serious complication of allogeneic bone marrow transplantation (allo-BMT), driven by T cell responses.

Purpose of the Study:

• To investigate the role of CD11c in T cell activation and differentiation.
• To determine the involvement of CD11c in the pathogenesis of aGVHD.
• To explore the molecular mechanisms by which CD11c influences immune responses.

Main Methods:

• Blocking CD11c on human monocyte-derived DCs (MoDCs) and assessing T cell proliferation and differentiation.
• Utilizing CD11c-deficient murine models in allo-BMT to evaluate aGVHD severity.
• Performing transcriptional analysis and co-culture assays with CD11c-deficient bone marrow-derived DCs (BMDCs).
• Investigating molecular interactions of CD11c with MHCII, Hsp90, and signaling pathways (Akt, Erk1/2).

Main Results:

• Inhibition of CD11c on MoDCs reduced CD4+ T cell proliferation and differentiation into IFN-γ-producing T helper 1 (Th1) cells.
• CD11c-deficient recipient mice exhibited alleviated aGVHD symptoms with decreased IFN-γ+ CD4+ Th1 and CD8+ T cells.
• CD11c deficiency impaired antigen presentation by BMDCs.
• CD11c was found to interact with MHCII and Hsp90, influencing Akt and Erk1/2 phosphorylation in DCs.

Conclusions:

• CD11c plays a critical role in promoting T cell responses essential for aGVHD pathogenesis.
• CD11c is vital for maintaining the antigen-presenting function of DCs.
• CD11c represents a potential therapeutic target for preventing and treating aGVHD.