Evolution of an attenuated HIV-1 isolate in an elite suppressor

Exceptional, naturally occurring HIV-1 control: Insight into a functional cure

Exceptional elite controllers represent an extremely rare group of people with HIV-1 (PWH) who exhibit spontaneous, high-level control of viral replication below the limits of detection in sensitive clinical monitoring assays and without disease progression in the absence of antiretroviral therapy for prolonged periods, frequently exceeding 25 years. Here, we discuss the different cases that have been reported in the scientific literature, their unique genetic, virological, and immunological characteristics, and their relevance as the best model for the functional cure of HIV-1.

Modulation of TCR-dependent NFAT signaling is impaired in HIV-1 Nef isolates from elite controllers

HIV-1 Nef modulates the activation state of CD4⁺ T cells by altering signaling events elicited by the T cell receptor (TCR). Primary nef sequences exhibit extensive inter-individual diversity that influences their ability to downregulate CD4 and HLA class I; however, the impact of nef variation on modulation of T cell signaling is poorly characterized. Here, we measured TCR-mediated activation of NFAT transcription factor in the presence of nef alleles isolated from 45 elite controllers (EC) and 46 chronic progressors (CP). EC Nef clones displayed lower ability to inhibit NFAT signaling (median 87 [IQR 75-93]% relative to SF2 Nef) compared to CP clones (94 [IQR 89-98]%) (p < 0.001). Polymorphisms in Nef's N-terminal domain impaired its ability to inhibit NFAT signaling. Results indicate that primary nef alleles exhibit a range of abilities to modulate TCR-dependent NFAT signaling, implicating natural variation in this function as a potential contributor to differential HIV-1 pathogenesis.

Characterization of Elite Suppressors Cell-Associated HIV-1 mRNA at Baseline and with T Cell Activation

Objective: Elite Controllers or Suppressors (ES) are patients who control HIV replication without antiretroviral therapy. In this study, we compared baseline and inducible HIV-1 mRNA levels in CD4+ T cells from ES and chronic progressors (CPs) receiving suppressive antiretroviral therapy. Methods: We quantified basal levels of cell associated HIV-1 mRNA in CD4+ T cells isolated from CPs and ES. Additionally, we measured the fold upregulation of intracellular HIV-mRNA after stimulation of CD4+ T cells with phorbol 12-myristate 13-acetate (PMA) and ionomycin, and quantified the amount of HIV-mRNA levels released into culture supernatant. Results: ES have significantly less cell associated HIV-mRNA per 5x10⁶ cells (p = 0.003); 8 of 10 CPs had quantifiable HIV-1 mRNA at baseline, whereas this was present in only 2 of 10 ES. Upon stimulation with PMA and ionomycin, 4 of 5 CPs and 7 of 9 ES showed increased cell associated HIV-mRNA. Interestingly, released HIV-1 mRNA could be detected in supernatants of CD4+ T cells stimulated with PMA/ionomycin from 5 of 8 ES. Conclusion: Our results demonstrate that while the baseline levels of cell associated HIV-1 mRNA are significantly lower in ES compared to CPs, stimulation of CD4+ T cells results in a comparable relative upregulation of viral transcription.