Rafael Delgado’s research while affiliated with Complutense University of Madrid and other places

Background: SARS-CoV-2 was the causing agent of the COVID-19 pandemic, which resulted in millions of deaths worldwide and massive economic losses. Although there are already several vaccines licensed, as novel variants develop, understanding the immune response induced by vaccination and natural infection is key for the development of future vaccines. Methods: In this study, we have used flow cytometry and next-generation sequencing to assess the longitudinal CD8+ T-cell response against natural infection and vaccination in convalescent and vaccinated individuals, from early activation to immune memory establishment. Moreover, we have characterized the T-cell receptor clonality and diversity at different stages post-infection and post-vaccination. Results: We have found no significant differences in CD8+ T-cell activation during the first three weeks post-infection compared to the first three weeks after first vaccination. Conversely, natural infection resulted in sustained high levels of T-cell activation at four weeks post-infection, a point in which we observed a decline in T-cell activation post-vaccination despite boosting with a second vaccination shot. Moreover, additional vaccination did not result in enhanced T-cell activation. Of note, we have observed variations in the memory subset structure at every stage of disease and vaccination. Overall, both infection and immunization induced a highly diverse T-cell receptor repertoire, which was observed both between study groups and between patients inside a given group. Conclusions: These data contribute to expand our knowledge about the immune response to SARS-CoV-2 infection and vaccination and call for additional strategies to enhance T-cell responses by booster immunization.

Monocyte-derived macrophages recruited into inflamed tissues can acquire an array of functional states depending on the extracellular environment. Since the anti-inflammatory/pro-fibrotic macrophage profile is determined by MAFB, whose activity/protein levels are regulated by GSK3, we addressed the macrophage reprogramming potential of GSK3 modulation. GM-CSF-dependent (GM-MØ) and M-CSF-dependent monocyte-derived macrophages (M-MØ) exhibited distinct levels of inactive GSK3, and inhibiting GSK3 in GM-MØ led to the acquisition of transcriptional, phenotypic, and functional properties characteristic of M-MØ (enhanced expression of IL-10 and monocyte-recruiting factors, and higher efferocytosis). These reprogramming effects were also observed upon GSK3α/β knockdown and through GSK3 inhibition in ex vivo isolated human alveolar macrophages (AMØ). Notably, GSK3 downmodulation potentiated the transcriptional signature of interstitial macrophages (IMØ) while suppressing the AMØ-specific gene profile. Indeed, heightened levels of inactive GSK3 and MAFB-dependent proteins were observed in severe COVID-19 patients’ lung macrophages, highlighting the GSK3-MAFB axis as a therapeutic target for macrophage reprogramming.

Monocyte-derived macrophages recruited into inflamed tissues can acquire an array of functional states depending on the extracellular environment. Since the anti-inflammatory/pro-fibrotic macrophage profile is determined by MAFB, whose activity/protein levels are regulated by GSK3, we addressed the macrophage re-programming potential of GSK3 modulation. GM-CSF-dependent (GM-MØ) and M-CSF-dependent monocyte-derived macrophages (M-MØ) exhibited distinct levels of inactive GSK3, and inhibiting GSK3 in GM-MØ led to acquisition of transcriptional, phenotypic and functional properties characteristic of M-MØ (enhanced expression of IL-10 and monocyte-recruiting factors, and higher efferocytosis). These re-programming effects were also observed upon GSK3α/β knockdown, and through GSK3 inhibition in ex vivo isolated human alveolar macrophages (AMØ). Notably, GSK3 downmodulation potentiated the transcriptional signature of Interstitial Macrophages (IMØ) while suppressed the AMØ-specific gene profile. Indeed, heightened levels of inactive GSK3 and MAFB-dependent proteins were observed in severe COVID-19 patients lung macrophages, highlighting the GSK3-MAFB axis as a therapeutic target for macrophage re-programming.

Background We investigated the efficacy of dolutegravir/lamivudine for maintenance treatment for people with HIV and previous lamivudine resistance. Methods Open-label, single arm, multicentric clinical trial including virologically suppressed PWH with historical lamivudine resistance (confirmed by genotypic testing or suspected based on clinical history), no integrase resistance and CD4+ >200 cells/mm3 whose ART was changed to dolutegravir/lamivudine if the M184V/I mutation was not detected in baseline proviral DNA population sequencing. Proviral DNA next-generation sequencing (NGS) was retrospectively performed in baseline samples. Primary endpoint was proportion of participants with HIV-1 RNA viral load (VL) ≥50 copies/mL at 48 weeks in the intention-to-treat-exposed (ITT-e) population using the Food and Drug Administration snapshot algorithm. Results 121 participants enrolled, 114 with a prior genotype with M184V/I, mean virological suppression of 9 years. 24 (19·8%) had the M184V/I in baseline proviral DNA NGS (>5% threshold). At 48 weeks, 4 participants had a VL ≥50 copies/mL (3·3%, 95% CI: 0·9%-8·2%, FDA-Snapshot ITT-e): 1 confirmed virologic withdrawal, 1 precautionary virologic withdrawal and 2 discontinued from study treatment for other reasons with last VL ≥ 50 copies/mL; none had M184V/I in baseline proviral DNA NGS and there was no emergent integrase resistance. 90·1% participants (109/121) had a VL<50 copies/mL (95% CI: 83·3%-94·8%) and there were no data for 6·6 % (8/121 participants) at 48 weeks. Conclusions After excluding lamivudine mutations in proviral DNA by population sequencing, dolutegravir/lamivudine effectively maintained virological suppression in PWH with CD4+ >200 cells/mm3 and history of lamivudine resistance. Notably, no treatment-emergent resistance was observed.

Small solid silica nanoparticles (SiNPs) have been used for multivalent carbohydrate presentation in DC-/L-SIGN-mediated viral infection models. Glycosylated SiNPs (glycoSiNPs) were fully characterized by different experimental techniques, including NMR, DLS, TGA, FTIR, and XPS, which confirmed their chemical structures. As a proof-of-concept, the capacity of glycoSiNPs to interact with Concanavalin A (ConA), a model lectin, using DLS binding experiments and UV−vis turbidimetry assays was analyzed. Their antiviral activity was assessed in a cellular assay using an artificial Ebola virus, demonstrating the potent inhibition of DC-SIGN-mediated infection. Notably, glycoSiNPs functionalized with a trivalent Manα1,2Man glycodendron exhibited the strongest inhibitory activity, with an IC50 of 135 ng/mL and a 170-fold lower efficiency in blocking L-SIGN-mediated viral infection. These findings suggest that glycoSiNPs present a promising approach for developing antiviral agents that selectively target the DC-SIGN pathway over the L-SIGN one.

Monocyte-derived macrophages recruited into inflamed tissues can acquire an array of functional states depending on the extracellular environment. Since the anti-inflammatory/pro-fibrotic macrophage profile is determined by MAFB, whose activity/protein levels are regulated by GSK3, we addressed the macrophage re-programming potential of GSK3 modulation. GM-CSF-dependent (GM-MØ) and M-CSF-dependent monocyte-derived macrophages (M-MØ) exhibited distinct levels of inactive GSK3, and inhibiting GSK3 in GM-MØ led to acquisition of transcriptional, phenotypic and functional properties characteristic of M-MØ (enhanced expression of IL-10 and monocyte-recruiting factors, and higher efferocytosis). These re-programming effects were also observed upon GSK3α/β knockdown, and through GSK3 inhibition in ex vivo isolated human alveolar macrophages (AMØ). Notably, GSK3 downmodulation potentiated the transcriptional signature of Interstitial Macrophages (IMØ) while suppressed the AMØ-specific gene profile. Indeed, heightened levels of inactive GSK3 and MAFB-dependent proteins were observed in severe COVID-19 patients lung macrophages, highlighting the GSK3-MAFB axis as a therapeutic target for macrophage re-programming.

Monocyte-derived macrophages recruited into inflamed tissues can acquire an array of functional states depending on the extracellular environment. Since the anti-inflammatory/pro-fibrotic macrophage profile is determined by MAFB, whose activity/protein levels are regulated by GSK3, we addressed the macrophage re-programming potential of GSK3 modulation. GM-CSF-dependent (GM-MØ) and M-CSF-dependent monocyte-derived macrophages (M-MØ) exhibited distinct levels of inactive GSK3, and inhibiting GSK3 in GM-MØ led to acquisition of transcriptional, phenotypic and functional properties characteristic of M-MØ (enhanced expression of IL-10 and monocyte-recruiting factors, and higher efferocytosis). These re-programming effects were also observed upon GSK3α/β knockdown, and through GSK3 inhibition in ex vivo isolated human alveolar macrophages (AMØ). Notably, GSK3 downmodulation potentiated the transcriptional signature of Interstitial Macrophages (IMØ) while suppressed the AMØ-specific gene profile. Indeed, heightened levels of inactive GSK3 and MAFB-dependent proteins were observed in severe COVID-19 patients lung macrophages, highlighting the GSK3-MAFB axis as a therapeutic target for macrophage re-programming.