Restriction of HIV-1 infection in sickle cell disease trait

We recently showed that in Sickle Cell Disease (SCD), activation of anti-viral restriction factor SAMHD1 and NF-κB inhibitor, IkBα prevented ex vivo HIV-1 infection. SAMHD1 activation was due to its reduced phosphorylation by CDK2, whose activity was inhibited by reduced intracellular iron levels in SCD peripheral blood mononuclear cells (PBMC). We also found that a hazard ratio associated with HIV infection among 11,412 SCD trait subjects was 1.0% comparing to >2% HIV-1 infection among African-Americans in USA. We compared 9 HbAS HIV-1 infected individuals with 107 HbAA or HbAC HIV-1 infected individuals who were enrolled at Howard University clinic. While hemoglobin levels in these two groups were not significantly different, HIV-1 viral load was significantly lower in HbAS group as well the number of HIV-1 associated complications (Hospitalization) were reduced. In the present study, we analyzed ex vivo HIV-1 infection of SCD trait PBMC and determined the expression of iron and hypoxia-regulated host factors including HO-1, NFκB, IKK, IKBα that are implicated in HIV-1 replication. We also analyzed CDK2 activity, SAMHD1 phosphorylation and RNR2 expression in SCD trait PBMCs. One round HIV-1 infection was significantly reduced in in SCD trait PBMC. Expression of HO-1 and IKBα was upregulated in SCD trait whereas IKK and NF-κB expression was downregulated. While CDK2 activity and SAMHD1 phosphorylation were not changed, RNR2 expression was reduced. Expression levels of HIV-1 env and gag mRNA were significantly lower in HIV-1 infected SCD trait subjects. In the same patients, HO-1 and IKBα mRNA levels were upregulated comparing to HIV-1+ HbAA or HbAC subjects. Our findings suggest that HIV-1 infection might be deregulation in SCD trait and that iron metabolism and hypoxia might play a role in this deregulation. Abstract source