T-cell exhaustion has been involved in the pathogenesis of HIV infection. We have longitudinally analyzed PD1 and Tim3 surrogate markers of T-cells exhaustion, in parallel with other markers of HIV ...progression, and its potential association with CD4 changes in treated and untreated infection.
96 HIV patients, 49 of them followed in the absence of cART (cART-naïve group) and 47 after initiation of cART (cART group) were included and followed for a median of 43 IQR: 31-60 months. PD1 and Tim3 expression, CD8 T-cells activation, recent thymic emigrants, activation/apoptosis and turnover of CD4 cells were assessed at baseline and during follow up. Univariate and multivariate associations with CD4 evolution were explored.
Parameters significantly associated with CD4 depletion in cART-naïve group were: baseline level (p = 0.02) and variation (p = 0.002) of PD1 and Tim3 co-expression on CD8, and variation of CD95 expression on CD4 (p = 0.007). Parameters significantly associated with CD4 restoration in cART group were: baseline level of CD38+HLADR- subset of CD8 (p = 0.01), variation of PD1 expression on CD8 (p = 0.036), variation of Tim3 expression on CD4 (p = 0.039) and variation of CD95 expression on CD4 (p = 0.035).
Our results suggest that PD1 and Tim3 markers of exhaustion have a pivotal role in CD4 dynamics in HIV patients and its down-regulation would be a desirable effect of immunotherapies aimed to restore CD4 T-cell pool during progression of HIV infection.
The longevity-promoting NAD⁺–dependent class III histone deacetylase Sirtuin 1 (SIRT1) is involved in stem cell function by controlling cell fate decision and/or by regulating the p53-dependent ...expression of NANOG. We show that SIRT1 is down-regulated precisely during human embryonic stem cell differentiation at both mRNA and protein levels and that the decrease in Sirt1 mRNA is mediated by a molecular pathway that involves the RNA-binding protein HuR and the arginine methyltransferase coactivator-associated arginine methyltransferase 1 (CARM1). SIRT1 down-regulation leads to reactivation of key developmental genes such as the neuroretinal morphogenesis effectors DLL4, TBX3, and PAX6, which are epigenetically repressed by this histone deacetylase in pluripotent human embryonic stem cells. Our results indicate that SIRT1 is regulated during stem cell differentiation in the context of a yet-unknown epigenetic pathway that controls specific developmental genes in embryonic stem cells.
Studies investigating the cumulative incidence of and immune status against SARS‐CoV‐2 infection provide valuable information for shaping public health decision‐making. A cross‐sectional study on 935 ...participants, conducted in the Valencian Community (VC), measuring anti‐SARS‐CoV‐2‐receptor binding domain‐RBD‐total antibodies and anti‐Nucleocapsid (N)‐IgGs via electrochemiluminescence assays. Quantitation of neutralizing antibodies (NtAb) against ancestral and Omicron BA.1 and BA.2 variants and enumeration of SARS‐CoV‐2‐S specific‐IFNγ‐producing CD4+ and CD8+ T cells was performed in 100 and 137 participants, respectively. The weighted cumulative incidence was 51.9% (95% confidence interval CI: 48.7–55.1) and was inversely related to age. Anti‐RBD total antibodies were detected in 97% of participants; vaccinated and SARS‐CoV‐2‐experienced (VAC‐ex; n = 442) presented higher levels (p < 0.001) than vaccinated/naïve (VAC‐n; n = 472) and nonvaccinated/experienced (UNVAC‐ex; n = 63) subjects. Antibody levels correlated inversely with time elapsed since last vaccine dose in VAC‐n (Rho, −0.52; p < 0.001) but not in VAC‐ex (rho −0.02; p = 0.57). Heterologous booster shots resulted in increased anti‐RBD antibody levels compared with homologous schedules in VAC‐n, but not in VAC‐ex. NtAbs against Omicron BA.1 were detected in 94%, 75%, and 50% of VAC‐ex, VAC‐n and UNVAC‐ex groups, respectively. For Omicron BA.2, the figures were 97%, 84%, and 40%, respectively. SARS‐CoV‐2‐S‐reactive IFN‐γ T cells were detected in 73%, 75%, and 64% of VAC‐ex, VAC‐n and UNVAC‐ex, respectively. Median frequencies for both T‐cell subsets were comparable across groups. In summary, by April 2022, around half of the VC population had been infected with SARS‐CoV‐2 and, due to extensive vaccination, displayed hybrid immunity.
We investigated whether peripheral blood levels of SARS‐CoV‐2 Spike (S) receptor binding domain antibodies (anti‐RBD), neutralizing antibodies (NtAb) targeting Omicron S, and S‐reactive‐interferon ...(IFN)‐γ‐producing CD4+ and CD8+ T cells measured after a homologous booster dose (3D) with the Comirnaty® vaccine was associated with the likelihood of subsequent breakthrough infections due to the Omicron variant. An observational study including 146 nursing home residents (median age, 80 years; range, 66–99; 109 female) evaluated for an immunological response after 3D (at a median of 16 days). Anti‐RBD total antibodies were measured by chemiluminescent immunoassay. NtAb were quantified by an Omicron S pseudotyped virus neutralization assay. SARS‐CoV‐2‐S specific‐IFNγ‐producing CD4+ and CD8+ T cells were enumerated by whole‐blood flow cytometry for intracellular cytokine staining. In total, 33/146 participants contracted breakthrough Omicron infection (symptomatic in 30/33) within 4 months after 3D. Anti‐RBD antibody levels were comparable in infected and uninfected participants (21 123 vs. 24 723 BAU/ml; p = 0.34). Likewise, NtAb titers (reciprocal IC50 titer, 157 vs. 95; p = 0.32) and frequency of virus‐reactive CD4+ (p = 0.82) and CD8+ (p = 0.91) T cells were similar across participants in both groups. anti‐RBD antibody levels and NtAb titers estimated at around the time of infection were also comparable (3445 vs. 4345 BAU/ml; p = 0.59 and 188.5 vs. 88.9; p = 0.70, respectively). Having detectable NtAb against Omicron or SARS‐CoV‐2‐S‐reactive‐IFNγ‐producing CD4+ or CD8+ T cells after 3D was not correlated with increased protection from breakthrough infection (OR, 1.50; p = 0.54; OR, 0.0; p = 0.99 and OR 3.70; p = 0.23, respectively). None of the immune parameters evaluated herein, including NtAb titers against the Omicron variant, may reliably predict at the individual level the risk of contracting COVID‐19 due to the Omicron variant in nursing home residents.
The production of human recombinant proteins to be used for therapeutic or nutritional purposes must focus on obtaining a molecule that is as close as possible to the native human protein. This ...biotechnological tool has been documented in various studies published in recent decades, with lactoferrin being one of those that has generated the most interest, being a promising option for recombinant technology. However, stability studies including thermodynamic parameters have not been reported for recombinant lactoferrin (Lf). The objective of this work was to obtain the human recombinant protein using the yeast
to study structural changes modifying pH and temperature using circular dichroism spectroscopy (CD). Thermodynamic parameters such as ΔH, ΔS and Tm were calculated and compared with commercial human lactoferrin. We propose the potential use of CD and thermodynamic parameters as a criterion in the production of recombinant proteins to be used in the production of specialized recombinant proteins.
Maytansinol is a valuable precursor for the preparation of maytansine derivatives (known as maytansinoids). Inspired by the intriguing structure of the macrocycle and the success in targeted cancer ...therapy of the derivatives, we explored the maytansinol acylation reaction. As a result, we were able to obtain a series of derivatives with novel modifications of the maytansine scaffold. We characterized these molecules by docking studies, by a comprehensive biochemical evaluation, and by determination of their crystal structures in complex with tubulin. The results shed further light on the intriguing chemical behavior of maytansinoids and confirm the relevance of this peculiar scaffold in the scenario of tubulin binders.
Exploring the maytansinol acylation reaction, we have discovered previously unreported structural modifications of the maytansine scaffold. This permitted the synthesis and full characterization of a series of novel maytansinoids. A comprehensive biochemical evaluation and X‐ray crystallography structure determinations of tubulin‐maytansinoids identified potent tubulin binders. Moreover, our investigation allowed us to evaluate the impact of the structural modifications described.
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•A lower COVID-19 mortality rate was observed in HIV patients.•Similar hospitalization and ICU admission rates were observed in HIV patients.•Age and comorbidities also represent the ...main poor COVID-19 prognostic factors in PLHIV.•HIV severity or type of antiretroviral treatment does not influence the COVID-19 outcome.
Information on how COVID-19 affects people living with HIV (PLHIV) remains scarce.
An observational study was conducted in four public hospitals in Madrid. All HIV patients with confirmed or suspected COVID-19 were included and compared with COVID-19 patients without HIV infection.
Sixty-three patients with HIV infection and confirmed or suspected COVID-19 were analyzed. The median age was 46 years (IQR: 37–56 years), and 88.9% were men. The median duration of HIV infection was 10.8 years (IQR: 6.5–16.8 years), and 96.8% were on antiretroviral therapy. 84.1% had previous comorbidities. The most common symptoms were fever (66.1%), cough (66.1%) and dyspnea (46.8%). Pneumonia was found in 47.5%, 28.6% of patients had severe disease, and 32.3% were admitted to hospital. The ICU admission rate and the mortality rate were both 3.17%. A significant association was observed between age, arterial hypertension, overweight, and diabetes mellitus and the severity of COVID-19. No association was observed between HIV-related factors and the severity of COVID-19. The rate of COVID-19 in HIV-patients was 1.68%. Similar hospitalization (31.74% vs 32.57%) and ICU admission (3.17% vs 2%) rates were observed with non-HIV infected patients. A lower mortality rate during hospitalization (10% vs 21.37%) and a lower global mortality rate (3.17% vs 6.96%) were also observed.
Established poor prognostic factors for COVID-19 patients, such as age and comorbidities, remain the main determinants for PLHIV. Neither the HIV severity nor the type of ARV treatment seem to influence the outcome of COVID-19. Large prospective cohorts are needed in order to establish the differences between HIV-positive and HIV-negative patients.
The spectrum of COVID-19 infection includes acute respiratory distress syndrome (ARDS) and macrophage activation syndrome (MAS), although the histological basis for these disorders has not been ...thoroughly explored. Post-mortem pulmonary and bone marrow biopsies were performed in 33 patients. Samples were studied with a combination of morphological and immunohistochemical techniques. Bone marrow studies were also performed in three living patients. Bone marrow post-mortem studies showed striking lesions of histiocytic hyperplasia with hemophagocytosis (HHH) in most (16/17) cases. This was also observed in three alive patients, where it mimicked the changes observed in hemophagocytic histiocytosis. Pulmonary changes included a combination of diffuse alveolar damage with fibrinous microthrombi predominantly involving small vessels, in particular the alveolar capillary. These findings were associated with the analytical and clinical symptoms, which helps us understand the respiratory insufficiency and reveal the histological substrate for the macrophage activation syndrome-like exhibited by these patients. Our results confirm that COVID-19 infection triggers a systemic immune-inflammatory disease and allow specific therapies to be proposed.
Genetic interventions on microbiomes, for clinical or biotechnological purposes, remain challenging. Conjugation-based delivery of genetic cargo is still unspecific and limited by low conjugation ...rates. Here we report an approach to overcome these problems, based on a synthetic bacterial adhesion system. Mating assemblers consist on a synthetic adhesion formed by the expression on the surface of donor and target cells of specific nanobodies (Nb) and their cognate antigen (Ag). The Nb-Ag bridge increased 1-3 logs transfer of a variety of plasmids, especially in liquid media, confirming that cell-cell docking is a main determinant limiting mating efficiency. Synthetic cell-to-cell adhesion allows efficient conjugation to targeted recipients, enhancing delivery of desired genes to a predefined subset of prey species, or even specific pathogenic strains such as enterohemorrhagic Escherichia coli (EHEC), within a bacterial community. The synthetic conjugation enhancer presented here optimizes plasmid delivery by selecting the target hosts with high selectivity.
Abstract
Background
Fast initiation of ART has been associated with higher rates of retention in HIV care and viral suppression at 48 weeks and with lower mortality rates. However, scarce evidence ...exists in our setting, where diagnosis and treatment are carried out in different contexts.
Methods
An observational retrospective study evaluating efficacy and safety of ART prescribed at the first specialist appointment, without baseline laboratory data, in a tertiary hospital in downtown Madrid. Individuals with a new diagnosis of HIV infection who initiated treatment at their first appointment with an infectious diseases specialist before receiving baseline laboratory results were included, irrespective of the ART regimen chosen.
Results
One hundred and eight participants were included. The majority (99.1%) were MSM who had acquired infection during sexual intercourse. The efficacy of ART, without baseline laboratory results at the time of initiation, was 85.2% (92/108) in the ITT analysis and 91.7% (99/108) in the treatment-related discontinuation equals failure analysis. All but nine patients presented an undetectable viral load (<50 copies/mL) at 48 weeks from starting ART. No serious adverse effects associated with the strategy were observed. In total, 101 participants continued care at 48 weeks with retention in HIV care rate of 93.5% (101/108).
Conclusions
Initiating ART at the first available opportunity without baseline laboratory data does not reduce efficacy or safety of ART and achieves rapid virological control with high rates of retention in HIV care.
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