Robust interferon-^α and IL-12 responses by dendritic cells are related to efficient CD4⁺ T-cell recovery in HIV patients on ART

Amongst HIV patients with successful virological responses to antiretroviral therapy (ART), poor CD4⁺ T-cell recovery is associated with low nadir CD4⁺ T-cell counts and persistent immune activation. These factors might be influenced by dendritic cell (DC) function. Interferon-^α-producing plasmacytoid DC and IL-12-producing myeloid DC were quantified by flow cytometry after stimulation with agonists to TLR7/8 (CL075) or TLR9 (CpG-ODN). These were compared between patients who achieved CD4⁺ T-cell counts above or below 200 cells/μL after 6months on ART (High vs. Low groups). High Group patients had more DC producing interferon-α or IL-12 at Weeks 6 and 12 on ART than Low Group patients. The frequencies of cytokine-producing DC at Week 12 were directly correlated with CD4⁺ T-cell counts at baseline and at Week 12. Patients with good recovery of CD4⁺ T-cells had robust TLR-mediated interferon-α responses by plasmacytoid DC and IL-12 responses by myeloid DC during early ART (1-3months).