Towards achieving a state of reversible HIV-1 latency in primary monocyte-derived macrophages (MDM) by M1 polarization

G. Poli, F. Graziano, E. Vicenzi
2015 Journal of virus eradication  
Whether myeloid cells are latently infected remains to be firmly established. In this regard, we have previously reported that short-term exposure of primary MDM to pro-inflammatory cytokines (IFN-γ plus TNF−α), i.e. "M1 polarization", partially prevented productive virus infection and reduced proviral transcription. Methods: M1-polarized MDM were restimulated with M1 cytokines R5 HIV-1 (M1 2 protocol). Cell cultures were monitored for supernatant-associated RT activity, HIV-1 DNA load,
more » ... /3A expression, and for cell reactivation by co-culture with T cell blasts. Results: We observed a significant, further reduction of virus replication down to near undetectable levels by RT activity over 30 days of culture. HIV-1 DNA levels were ca. 100-and 1,000-fold lower in M1-MDM and M1 2 -MDM vs. control, unpolarized cells, respectively. APOBEC3A, but not APOBEC3G, was significantly upregulated by the M1 2 protocol protocol 15 days post-infection. No effect of T cell blast co-culture on control, infected MDM was observed, whereas significant levels of RT activity were induced in M1 2 -MDM by this approach. Conclusions: Stimulation of already infected M1-MDM with proinflammatory, M1-cytokines counterintuitively resulted in a further, significant inhibition of virus replication down to "near-latency" levels in terms of RT activity and viral DNA levels and upregulation of APOBEC3A expression. Recovery of virus production was achieved by cocultivation of M1 2 -infected MDM with allogeneic T cell blasts, indicating the existence of a pool of infected cells carrying inducible proviruses. Additional experiments are ongoing to define the levels of integrated proviruses vs. total HIV-1 DNA by Alu-PCR, the reproducibility of the M1 2 protocol with a VSV-g pseudotyped single round virus, and the panel of stimuli capable of reactivating virus expression.
doi:10.1016/s2055-6640(20)31341-8 fatcat:jpcmvjlivrhyddyazzi5fugsru