Blocking CCL8-CCR8-Mediated Early Allograft Inflammation Improves Kidney Transplant Function

Area of Science:

• Immunology
• Transplantation Biology
• Renal Medicine

Background:

• Early allograft inflammation in kidney transplantation negatively impacts long-term graft survival.
• Identifying specific mediators of early kidney allograft inflammation is crucial for developing targeted therapies.

Purpose of the Study:

• To elucidate the key cellular and molecular players driving early inflammation in kidney allografts.
• To evaluate the therapeutic potential of targeting identified inflammatory mediators.

Main Methods:

• Utilized an allogeneic murine kidney transplant model.
• Investigated the role of donor kidney resident macrophages and the CCL8-CCR8 axis in early allograft response.

Main Results:

• Donor kidney resident macrophages rapidly expanded and expressed high levels of CCL8 within 3 days post-transplant.
• CCL8 promoted recipient monocyte infiltration and differentiation into macrophages, further increasing CCL8 expression.
• CCL8-CCR8 interaction led to enhanced infiltration of recipient T cells (CD4, CD8, γδ).
• Blocking CCL8-CCR8 or depleting donor macrophages significantly reduced immune cell infiltration and improved short-term allograft function.

Conclusions:

• The CCL8-CCR8 signaling pathway is a critical driver of early kidney allograft inflammation.
• Targeting the CCL8-CCR8 axis represents a promising therapeutic strategy to mitigate early post-transplant inflammation and enhance graft outcomes.