| First Author | Gusella GL | Year | 2016 |
| Journal | PLoS One | Volume | 11 |
| Issue | 6 | Pages | e0156486 |
| PubMed ID | 27310139 | Mgi Jnum | J:248878 |
| Mgi Id | MGI:6094542 | Doi | 10.1371/journal.pone.0156486 |
| Citation | Gusella GL, et al. (2016) Prothymosin-alpha Variants Elicit Anti-HIV-1 Response via TLR4 Dependent and Independent Pathways. PLoS One 11(6):e0156486 |
| abstractText | BACKGROUND: Prothymosin alpha (ProTalpha) (isoform 2: iso2) is a widely distributed, small acidic protein with intracellular and extracellular-associated functions. Recently, we identified two new ProTalpha variants with potent anti-HIV activity from CD8+ T cells and cervicovaginal lavage. The first is a splice variant of the ProTalpha gene known as isoB and the second is the product of ProTalpha pseudogene 7 (p7). Similarly to iso2, the anti-HIV activity of both variants is mediated by type I IFN. Here we tested whether the immunomodulatory activity of isoB and p7 are also TLR4 dependent and determined their kinetic of release in response to HIV-1 infection. METHODS: Type I, type III, TNF-alpha and IL-6 mRNA inducing activity was determined in macrophages from wild type and TLR4 knockout mice treated with recombinant ProTalpha variants. Supernatants from mock and HIV infected cells were analyzed by mass spectrometry in positive and negative modes for the presence of ProTalpha variants. In silico structural and functional analysis of ProTalpha variants were performed. RESULTS: We show that both isoB and p7 upregulate IFN-beta, IFN-lambda1, IL-6, TNF-alpha and RANTES mRNAs in primary human macrophages. The potent stimulation of IFN-beta by the recombinant ProTalpha variants in human macrophages is dependent on the TLR4 pathway, whereas the induction of TNF-alpha and IL-6 may also occur independently of TLR4, suggesting the interaction of ProTalpha variants with other signaling molecules/receptors. In silico analyses confirmed that the novel isoB and p7 variants are intrinsically disordered proteins, which lack the NLS and mass spectrometry showed release of ProTalpha variants within minutes post HIV-1 infection. These features are consistent with the function of ProTalpha variants as damage associate molecular patterns (DAMPs). CONCLUSIONS: Our findings indicate that ProTalpha variants strongly inhibit viral replication mainly, but not exclusively, through TLR4 signaling and that they are released within minutes of viral infection suggesting that they may function as DAMPs. |
