The Arp2/3 complex maintains genome integrity and survival of epidermal Langerhans cells

However, whether these networks play any role in the development and/or survival of myeloid cells in tissues remains open. Here, we found that the Arp2/3 complex, which is responsible for the nucleation of branched actin networks, is needed for the in vivo maintenance of epidermal Langerhans cells (LCs) throughout life.

Mice harboring a genetic deletion of the Arpc4 subunit of the complex form LC networks at birth, but these cells decline in numbers following a process reminiscent of premature cellular aging. By combining in vivo analyses of LCs with in vitro experiments on bone-marrow-derived dendritic cells, we found that Arpc4-deficient cells manage to progress through the cell cycle but accumulate DNA damage associated with aberrant nuclear shapes and events of nuclear envelope rupture.