Fig 5.

Induction of IL-10 in monocytes involves contact-dependent Treg activity and is also modulated by IL-27. CD14⁺ monocytes and CD25^hi CD127^lo Tregs from 8 untreated chronically HIV-1-infected subjects were purified by FACS sorting. Cell subsets were then cultured alone or in cocultures, and IL-10 was measured in supernatants after 3 days of incubation. (A) IL-10 production by Tregs and monocytes cultured alone. (B, C, and D) Monocytes were either cultured alone or cocultured with Tregs in direct contact (Mono+Treg) or separated by a Transwell membrane (Mono/Treg). (E) PBMCs from 8 untreated chronically infected individuals were cultured in the presence or absence of recombinant IL-27 receptor protein (IL-27R), and IL-10 was measured in the supernatants. (F) The same experiments were performed with the same persons after CD25 depletion. (G) Production of IL-27 in sorted CD14 monocytes and CD4 T cells was assessed by quantitative PCR. (H) IL-27 production was assessed in supernatants of purified monocytes cultured alone, purified Tregs cultured alone, or Tregs cultured with monocytes.