Percorrer por autor "Foxall, Russell B."
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- Early ART in Acute HIV-1 Infection: Impact on the B-Cell CompartmentPublication . Badura, Robert; Foxall, Russell B.; Ligeiro, Dario; Rocha, Miguel; Godinho-Santos, Ana; Trombetta, Amelia C.; Sousa, Ana E.HIV-1 infection induces B cell defects, not fully recovered upon antiretroviral therapy (ART). Acute infection and the early start of ART provide unique settings to address the impact of HIV on the B cell compartment. We took advantage of a cohort of 21 seroconverters, grouped according to the presence of severe manifestations likely mediated by antibodies or immune complexes, such as Guillain-Barré syndrome and autoimmune thrombocytopenic purpura, with a follow-up of 8 weeks upon effective ART. We combined B and T cell phenotyping with serum immunoglobulin level measurement and quantification of sj-KRECs and ΔB to estimate bone marrow output and peripheral proliferative history of B cells, respectively. We observed marked B cell disturbances, notably a significant expansion of cells expressing low levels of CD21, in parallel with markers of both impaired bone marrow output and increased peripheral B cell proliferation. This B cell dysregulation is likely to contribute to the severe immune-mediated conditions, as attested by the higher serum IgG and the reduced levels of sj-KRECs with increased ΔB in these individuals as compared to those patients with mild disease. Nevertheless, upon starting ART, the dynamic of B cell recovery was not distinct in the two groups, featuring both persistent alterations by week 8. Overall, we showed for the first time that acute HIV-1 infection is associated with decreased bone marrow B cell output assessed by sj-KRECs. Our study emphasizes the need to intervene in both bone marrow and peripheral responses to facilitate B cell recovery during acute HIV-1 infection.
- Shaping the founders : naïve CD4 T cell heterogeneity in people with HIV-1 or HIV-2Publication . Badura, Robert; Martins, Nicole C.; Farias, Guilherme B.; Tendeiro, Rita; Foxall, Russell B.; Santos, Diana F.; Gomes, André M. C.; Marques, Rita T.; Moleirinho, Beatriz; Godinho-Santos, Ana C.; Valadas, Emília; Gomes, Perpétua; Almeida, Afonso R. M.; Sousa, Ana E.Naïve CD4 T cells harbour functional subsets that influence the quality of immune reconstitution and the persistent viral reservoirs in people with HIV (PWH) under antiretroviral therapy (ART). Here, we profiled the circulating naïve CD4 T cells from PWH under effective ART with distinct past histories of viral burden, namely starting treatment early in acute or late in chronic stage HIV-1 infection, and people with HIV-2 (PWH2), who feature low to undetectable viremia before ART and slow disease progression. Spectral flow cytometry enabled us to capture the heterogeneity of this overlooked T cell compartment. Early-treated PWH1 maintained a naïve CD4 T cell profile comparable to that of age-matched seronegative individuals. Late-treated PWH1 and PWH2 showed distinct imbalances in conventional and regulatory subpopulations, yet both exhibited a relative expansion of CD31-expressing naïve cells, consistent with an IL-7-mediated homeostatic response. The ability of purified naïve CD4 T cells to respond to IL-7 was evaluated in additional cohorts of untreated PWH, revealing reduced proliferation and increased p21 transcription in PWH1 elite controllers. Additionally, a significant decline in proviral DNA was found in PWH2, suggesting an impact of IL-7 on HIV-2-infected naïve CD4 T cells that was not observed in the case of HIV-1 infection. Unravelling the homeostatic pathways and functional implications of naïve CD4 T cell heterogeneity will help clarify viral reservoir dynamics and inflammation in PWH and define strategies to prevent immune senescence.