Structural basis for distinct roles of SMAD2 and SMAD3 in FOXH1 pioneer-directed TGF-ß signaling.

TGF-ß receptors phosphorylate SMAD2 and SMAD3 transcription factors, which then form heterotrimeric complexes with SMAD4 and cooperate with context-specific transcription factors to activate target genes. Here we provide biochemical and structural evidence showing that binding of SMAD2 to DNA depends on the conformation of the E3 insert, a structural element unique to SMAD2 and previously thought to render SMAD2 unable to bind DNA. Based on this finding, we further delineate TGF-ß signal transduction by defining distinct roles for SMAD2 and SMAD3 with the forkhead pioneer factor FOXH1 as a partner in the regulation of differentiation genes in mouse mesendoderm precursors. FOXH1 is prebound to target sites in these loci and recruits SMAD3 independently of TGF-ß signals, whereas SMAD2 remains predominantly cytoplasmic in the basal state and set to bind SMAD4 and join SMAD3:FOXH1 at target promoters in response to Nodal TGF-ß signals. The results support a model in which signal-independent binding of SMAD3 and FOXH1 prime mesendoderm differentiation gene promoters for activation, and signal-driven SMAD2:SMAD4 binds to promoters that are preloaded with SMAD3:FOXH1 to activate transcription.

A Cluster-Randomized Trial of Hydroxychloroquine for Prevention of Covid-19.

BACKGROUND: Current strategies for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited to nonpharmacologic interventions. Hydroxychloroquine has been proposed as a postexposure therapy to prevent coronavirus disease 2019 (Covid-19), but definitive evidence is lacking. METHODS: We conducted an open-label, cluster-randomized trial involving asymptomatic contacts of patients with polymerase-chain-reaction (PCR)-confirmed Covid-19 in Catalonia, Spain. We randomly assigned clusters of contacts to the hydroxychloroquine group (which received the drug at a dose of 800 mg once, followed by 400 mg daily for 6 days) or to the usual-care group (which received no specific therapy). The primary outcome was PCR-confirmed, symptomatic Covid-19 within 14 days. The secondary outcome was SARS-CoV-2 infection, defined by symptoms compatible with Covid-19 or a positive PCR test regardless of symptoms. Adverse events were assessed for up to 28 days. RESULTS: The analysis included 2314 healthy contacts of 672 index case patients with Covid-19 who were identified between March 17 and April 28, 2020. A total of 1116 contacts were randomly assigned to receive hydroxychloroquine and 1198 to receive usual care. Results were similar in the hydroxychloroquine and usual-care groups with respect to the incidence of PCR-confirmed, symptomatic Covid-19 (5.7% and 6.2%, respectively; risk ratio, 0.86 [95% confidence interval, 0.52 to 1.42]). In addition, hydroxychloroquine was not associated with a lower incidence of SARS-CoV-2 transmission than usual care (18.7% and 17.8%, respectively). The incidence of adverse events was higher in the hydroxychloroquine group than in the usual-care group (56.1% vs. 5.9%), but no treatment-related serious adverse events were reported. CONCLUSIONS: Postexposure therapy with hydroxychloroquine did not prevent SARS-CoV-2 infection or symptomatic Covid-19 in healthy persons exposed to a PCR-positive case patient. (Funded by the crowdfunding campaign YoMeCorono and others; BCN-PEP-CoV2 ClinicalTrials.gov number, NCT04304053.).

Long-term effect of asthma on the development of obesity among adults: an international cohort study, ECRHS.

INTRODUCTION: Obesity is a known risk factor for asthma. Although some evidence showed asthma causing obesity in children, the link between asthma and obesity has not been investigated in adults. METHODS: We used data from the European Community Respiratory Health Survey (ECRHS), a cohort study in 11 European countries and Australia in 3 waves between 1990 and 2014, at intervals of approximately 10 years. We considered two study periods: from ECRHS I (t) to ECRHS II (t+1), and from ECRHS II (t) to ECRHS III (t+1). We excluded obese (body mass index≥30 kg/m2) individuals at visit t. The relative risk (RR) of obesity at t+1 associated with asthma at t was estimated by multivariable modified Poisson regression (lag) with repeated measurements. Additionally, we examined the association of atopy and asthma medication on the development of obesity. RESULTS: We included 7576 participants in the period ECRHS I-II (51.5% female, mean (SD) age of 34 (7) years) and 4976 in ECRHS II-III (51.3% female, 42 (8) years). 9% of participants became obese in ECRHS I-II and 15% in ECRHS II-III. The risk of developing obesity was higher among asthmatics than non-asthmatics (RR 1.22, 95% CI 1.07 to 1.38), and particularly higher among non-atopic than atopic (1.47; 1.17 to 1.86 vs 1.04; 0.86 to 1.27), those with longer disease duration (1.32; 1.10 to 1.59 in >20 years vs 1.12; 0.87 to 1.43 in ≤20 years) and those on oral corticosteroids (1.99; 1.26 to 3.15 vs 1.15; 1.03 to 1.28). Physical activity was not a mediator of this association. CONCLUSION: This is the first study showing that adult asthmatics have a higher risk of developing obesity than non-asthmatics, particularly those non-atopic, of longer disease duration or on oral corticosteroids.

Breastfeeding is associated with the intelligence of school-age children in Mexico.

Breastfeeding has been consistently associated with higher intelligence since childhood. However, this relation could be confounded due to maternal selection bias. We estimated the association between predominant breastfeeding and intelligence in school-age children considering potential selection bias and we simulated the intelligence gap reduction between low versus higher socioeconomic status children by increasing breastfeeding. We analysed predominant breastfeeding practices (breastmilk and water-based liquids) of children 0-3 years included in the Mexican Family Life Survey (MxFLS-1). Intelligence was estimated as the z-score of the abbreviated Raven score, measured at 6-12 years in the MxFLS-2 or MxFLS-3. We predicted breastfeeding duration among children with censored data with a Poisson model. We used the Heckman selection model to assess the association between breastfeeding and intelligence, correcting for selection bias and stratified by socioeconomic status. Results show after controlling for selection bias, a 1-month increase in predominant breastfeeding duration was associated with a 0.02 SD increase in the Raven z-score (p < 0.05). The children who were predominantly breastfed for 4-6 months versus <1 month had 0.16 SD higher Raven z-score (p < 0.05). No associations were found using multiple linear regression models. Among low socioeconomic status children, increasing predominantly breastfeeding duration to 6 months would increase their mean Raven z-score from -0.14 to -0.07 SD and reduce by 12.5% the intelligence gap with high socioeconomic status children. In conclusion, predominant breastfeeding duration was significantly associated with childhood intelligence after controlling for maternal selection bias. Increased breastfeeding duration may reduce poverty-driven intelligence inequities.

Association between the Prime Diet Quality Score and depressive symptoms in a Mediterranean population with metabolic syndrome. Cross-sectional and 2-year follow-up assessment from PREDIMED-PLUS study.

The burden of depression is increasing worldwide, specifically in older adults. Unhealthy dietary patterns may partly explain this phenomenon. In the Spanish PREDIMED-Plus study, we explored (1) the cross-sectional association between the adherence to the Prime Diet Quality Score (PDQS), an a priori-defined high-quality food pattern, and the prevalence of depressive symptoms at baseline (cross-sectional analysis) and (2) the prospective association of baseline PDQS with changes in depressive symptomatology after 2 years of follow-up. After exclusions, we assessed 6612 participants in the cross-sectional analysis and 5523 participants in the prospective analysis. An energy-adjusted high-quality dietary score (PDQS) was assessed using a validated FFQ. The cross-sectional association between PDQS and the prevalence of depression or presence of depressive symptoms and the prospective changes in depressive symptoms were evaluated through multivariable regression models (logistic and linear models and mixed linear-effects models). PDQS was inversely associated with depressive status in the cross-sectional analysis. Participants in the highest quintile of PDQS (Q5) showed a significantly reduced odds of depression prevalence as compared to participants in the lowest quartile of PDQS (Q1) (OR (95 %) CI = 0·82 (0·68, 0·98))). The baseline prevalence of depression decreased across PDQS quintiles (Pfor trend = 0·015). A statistically significant association between PDQS and changes in depressive symptoms after 2-years follow-up was found (ß (95 %) CI = -0·67 z-score (-1·17, -0·18). A higher PDQS was cross-sectionally related to a lower depressive status. Nevertheless, the null finding in our prospective analysis raises the possibility of reverse causality. Further prospective investigation is required to ascertain the association between PDQS and changes in depressive symptoms along time.

Hydroxychloroquine for Early Treatment of Adults With Mild Coronavirus Disease 2019: A Randomized, Controlled Trial.

BACKGROUND: No effective treatments for coronavirus disease 2019 (COVID-19) exist. We aimed to determine whether early treatment with hydroxychloroquine (HCQ) would be efficacious for outpatients with COVID-19. METHODS: Multicenter open-label, randomized, controlled trial conducted in Catalonia, Spain, between 17 March and 26 May 2020. Patients recently diagnosed with <5-day of symptom onset were assigned to receive HCQ (800 mg on day 1 followed by 400 mg once daily for 6 days) or usual care. Outcomes were reduction of viral load in nasopharyngeal swabs up to 7 days after treatment start, disease progression up to 28 days, and time to complete resolution of symptoms. Adverse events were assessed up to 28 days. RESULTS: A total of 293 patients were eligible for intention-to-treat analysis: 157 in the control arm and 136 in the intervention arm. The mean age was 41.6 years (SD, 12.6), mean viral load at baseline was 7.90 log10 copies/mL (SD, 1.82), and median time from symptom onset to randomization was 3 days. No differences were found in the mean reduction of viral load at day 3 (-1.41 vs -1.41 log10 copies/mL in the control and intervention arm, respectively) or at day 7 (-3.37 vs -3.44). Treatment did not reduce risk of hospitalization (7.1% control vs 5.9% intervention) nor shorten the time to complete resolution of symptoms (12 days, control vs 10 days, intervention). No relevant adverse events were reported. CONCLUSIONS: In patients with mild COVID-19, no benefit was observed with HCQ beyond the usual care.

Kanban system applications in healthcare services: A literature review.

Lean Management method has been applied in several fields before its implementation in healthcare area. Among the different techniques associated with Lean, in this paper, we are focused on Kanban system, which is a method that presents several benefits such as inventory holding reduction or improvement of the employees' satisfaction. Our main objective is to carry out a literature review focused on Kanban methodology applied to health care. In this sense, this study can serve as a script to improve hospital management in pandemic periods, such as the one currently lived on COVID-19. We carry out a literature review searching in four different databases. We combine several terms to achieve our objective. We identify several articles which describe Kanban methodology applied to health field. More specifically, we present in what areas (nursing or pharmacy, among others) this method has been applied. In addition, we show all the barriers as well as benefits caused by the implementation of this system. There are a few studies focused on analysing how Kanban is applied to health care. Therefore, we can affirm that this topic is still recent.

TGIF1 homeodomain interacts with Smad MH1 domain and represses TGF-ß signaling.

TGIF1 is a multifunctional protein that represses TGF-ß-activated transcription by interacting with Smad2-Smad4 complexes. We found that the complex structure of TGIF1-HD bound to the TGACA motif revealed a combined binding mode that involves the HD core and the major groove, on the one hand, and the amino-terminal (N-term) arm and the minor groove of the DNA, on the other. We also show that TGIF1-HD interacts with the MH1 domain of Smad proteins, thereby indicating that TGIF1-HD is also a protein-binding domain. Moreover, the formation of the HD-MH1 complex partially hinders the DNA-binding site of the complex, preventing the efficient interaction of TGIF1-HD with DNA. We propose that the binding of the TGIF1 C-term to the Smad2-MH2 domain brings both the HD and MH1 domain into close proximity. This local proximity facilitates the interaction of these DNA-binding domains, thus strengthening the formation of the protein complex versus DNA binding. Once the protein complex has been formed, the TGIF1-Smad system would be released from promoters/enhancers, thereby illustrating one of the mechanisms used by TGIF1 to exert its function as an active repressor of Smad-induced TGF-ß signaling.

RNA recognition and self-association of CPEB4 is mediated by its tandem RRM domains.

Cytoplasmic polyadenylation is regulated by the interaction of the cytoplasmic polyadenylation element binding proteins (CPEB) with cytoplasmic polyadenylation element (CPE) containing mRNAs. The CPEB family comprises four paralogs, CPEB1-4, each composed of a variable N-terminal region, two RNA recognition motif (RRM) and a C-terminal ZZ-domain. We have characterized the RRM domains of CPEB4 and their binding properties using a combination of biochemical, biophysical and NMR techniques. Isothermal titration calorimetry, NMR and electrophoretic mobility shift assay experiments demonstrate that both the RRM domains are required for an optimal CPE interaction and the presence of either one or two adenosines in the two most commonly used consensus CPE motifs has little effect on the affinity of the interaction. Both the single RRM1 and the tandem RRM1-RRM2 have the ability to dimerize, although representing a minor population. Self-association does not affect the proteins' ability to interact with RNA as demonstrated by ion mobility-mass spectrometry. Chemical shift effects measured by NMR of the apo forms of the RRM1-RRM2 samples indicate that the two domains are orientated toward each other. NMR titration experiments show that residues on the ß-sheet surface on RRM1 and at the C-terminus of RRM2 are affected upon RNA binding. We propose a model of the CPEB4 RRM1-RRM2-CPE complex that illustrates the experimental data.

Improved prediction of salvage antiretroviral therapy outcomes using ultrasensitive HIV-1 drug resistance testing.

BACKGROUND: The clinical relevance of ultrasensitive human immunodeficiency virus type 1 (HIV-1) genotypic resistance testing in antiretroviral treatment (ART)-experienced individuals remains unknown. METHODS: This was a retrospective, multicentre, cohort study in ART-experienced, HIV-1-infected adults who initiated salvage ART including, at least 1 ritonavir-boosted protease inhibitor, raltegravir or etravirine. Presalvage ART Sanger and 454 sequencing of plasma HIV-1 were used to generate separate genotypic sensitivity scores (GSS) using the HIVdb, ANRS, and REGA algorithms. Virological failure (VF) was defined as 2 consecutive HIV-1 RNA levels ≥200 copies/mL at least 12 weeks after salvage ART initiation, whereas subjects remained on the same ART. The ability of Sanger and 454-GSS to predict VF was assessed by receiver operating characteristic (ROC) curves and survival analyses. RESULTS: The study included 132 evaluable subjects; 28 (21%) developed VF. Using HIVdb, 454 predicted VF better than Sanger sequencing in the ROC curve analysis (area under the curve: 0.69 vs 0.60, Delong test P = .029). Time to VF was shorter for subjects with 454-GSS < 3 vs 454-GSS ≥ 3 (Log-rank P = .003) but not significantly different between Sanger-GSS < 3 and ≥3. Factors independently associated with increased risk of VF in multivariate Cox regression were a 454-GSS < 3 (HR = 4.6, 95 CI, [1.5, 14.0], P = .007), and the number of previous antiretrovirals received (HR = 1.2 per additional drug, 95 CI, [1.1, 1.3], P = .001). Equivalent findings were obtained with the ANRS and REGA algorithms. CONCLUSIONS: Ultrasensitive HIV-1 genotyping improves GSS-based predictions of virological outcomes of salvage ART relative to Sanger sequencing. This may improve the clinical management of ART-experienced subjects living with HIV-1. CLINICAL TRIALS REGISTRATION: NCT01346878.

Bridging Metabolic-Associated Steatotic Liver Disease and Cardiovascular Risk: A Potential Role for Ketogenesis.

The prevalence of cardiovascular diseases (CVDs) is a growing global health concern. Recent advances have demonstrated significant reductions in acute cardiovascular events through the management of modifiable cardiovascular risk factors. However, these factors are responsible for about 50% of the global cardiovascular disease burden. Considering that CVDs are one of the top mortality causes worldwide, the concept of residual cardiovascular risk is an important emerging area of study. Different factors have been proposed as sources of residual risk markers, including non-HDL particles characterization, as well as inflammation measured by serum and imaging technics. Among these, metabolic-associated steatotic liver disease (MASLD) remains controversial. Two opposing viewpoints contend: one positing that fatty liver disease merely reflects classical risk factors and thus adds no additional risk and another asserting that fatty liver disease independently impacts cardiovascular disease incidence. To address this dilemma, one hypothetical approach is to identify specific hepatic energy-yielding mechanisms and assess their impact on the cardiovascular system. Ketogenesis, a metabolic intermediate process particularly linked to energy homeostasis during fasting, might help to link these concepts. Ketogenic metabolism has been shown to vary through MASLD progression. Additionally, newer evidence supports the significance of circulating ketone bodies in cardiovascular risk prediction. Furthermore, ketogenic metabolism modification seems to have a therapeutic impact on cardiovascular and endothelial damage. Describing the relationship, if any, between steatotic liver disease and cardiovascular disease development through ketogenesis impairment might help to clarify MASLD's role in cardiovascular risk. Furthermore, this evidence might help to solve the controversy surrounding liver steatosis impact in CVD and might lead to a more accurate risk assessment and therapeutic targets in the pursuit of precision medicine.

The FF4 and FF5 domains of transcription elongation regulator 1 (TCERG1) target proteins to the periphery of speckles.

Transcription elongation regulator 1 (TCERG1) is a human factor implicated in interactions with the spliceosome as a coupler of transcription and splicing. The protein is highly concentrated at the interface between speckles (the compartments enriched in splicing factors) and nearby transcription sites. Here, we identified the FF4 and FF5 domains of TCERG1 as the amino acid sequences required to direct this protein to the periphery of nuclear speckles, where coordinated transcription/RNA processing events occur. Consistent with our localization data, we observed that the FF4 and FF5 pair is required to fold in solution, thus suggesting that the pair forms a functional unit. When added to heterologous proteins, the FF4-FF5 pair is capable of targeting the resulting fusion protein to speckles. This represents, to our knowledge, the first description of a targeting signal for the localization of proteins to sites peripheral to speckled domains. Moreover, this "speckle periphery-targeting signal" contributes to the regulation of alternative splicing decisions of a reporter pre-mRNA in vivo.

Expansion of antibody secreting cells and modulation of neutralizing antibody activity in HIV infected individuals undergoing structured treatment interruptions.

BACKGROUND: HIV-1 infection generates numerous abnormalities in the B cell compartment which can be partly reversed by antiretroviral therapy. Our aim was to evaluate the effects that re-exposure to HIV antigens might have on the frequency and functionality of antibody secreting cells (ASC) in patients undergoing structured treatment interruptions (STI). As re-exposure to viral antigens may also boost the production of (neutralizing) antibodies, we also assessed the neutralizing activities during STI cycles. METHODS: Retrospective study of 10 patients undergoing 3 cycles of STI with 2 weeks on and 4 weeks off HAART. ASC frequencies were determined by flow cytometry in samples obtained at the beginning and the end of STI. Neutralization capacity, total IgG concentration and anti-gp120-IgG titres were evaluated. RESULTS: As expected, median viral loads were higher at the end of STI compared to on-HAART time points. The level of CD27 and CD38 expressing ACS followed the same pattern; with ASC being elevated up to 16 fold in some patients (median increase of 3.5% ± 4.13). Eight out of 10 patients maintained stable total IgG levels during the study. After purifying IgG fractions from plasma, HIV-neutralizing activity was observed in the two subjects with highest anti-gp120 titers. In one of these patients the neutralizing activity remained constant while the other showed elevated neutralizing Ab after first STI and once treatment was reinitiated after the 2nd STI. CONCLUSIONS: Our data suggest that STI and its associated transient increases in viral load drive the frequencies of ASC in an antigen-specific manner. In some subjects, this re-exposure to autologous virus boosts the presence of neutralizing antibodies, similar to what is seen after influenza vaccination. STI may not boost clinically beneficial nAb levels but offers opportunities to isolate nAb producing cells at considerably higher levels than in subjects with completely suppressed viral replication.

Is Extracorporeal Shock Wave Lithotripsy a Treatment Option for Renal Colic?

BACKGROUND: Renal colic is characterized by sharp, intense flank pain. Nonsteroidal anti-inflammatory drugs are the treatment of choice, although extracorporeal shock wave lithotripsy (SWL) is a noninvasive alternative for pain management. The objective of our study is to present results obtained using rapid SWL to treat renal colic in our center. METHODS: We analyzed 214 patients undergoing rapid shockwave extracorporeal lithotripsy between October 2014 and June 2018: 69.63% were male, and 30.37% female, with a mean age of 47.35 years (range, 16-84). The average stone size was 6.71 mm (3-16). Stone locations were as follows: The pelviureteric junction (PUJ) (10.75%), proximal ureter (45.79%), midureter (24.77%), and distal ureter (18.69%). RESULTS: Pain relief was achieved in 81.31% of the patients. The rates of successful pain control according to stone location were 65.22% when the stone was located in the PUJ, 79.59% in the proximal ureter, 88.68% in the midureter, and 85.00% in the distal ureter. Complete or partial stone resolution was achieved 4 weeks postoperatively in 78.50% of cases (64.95% and 13.55%, respectively). According to the stone location, the overall rate of resolution (complete + partial) was 90.00% for distal ureteral stones, 86.80% in the midureter, 73.47% in the proximal ureter, and 60.86% in the PUJ. 44 patients (20.56%) demonstrated complications. The most common complications were persistent pain, acute renal failure and fever. CONCLUSIONS: Immediate SWL was found to be a safe and effective treatment option for pain related to renal colic in 81% of the patients studied.

Economic costs related to coronavirus disease 2019 pandemic: A systematic literature review.

Due to the COVID-19 pandemic, the pressure on healthcare systems has been tremendous and it is having a huge economic impact. The objective of this paper is to carry out a systematic literature review of the publications that have analysed the costs derived from COVID-19 from the patient's perspective. Not only is this study aimed at measuring the impact of COVID-19 in economic terms, but also in qualitative terms, analysing, for instance, the types of costs (direct and indirect) and their variations depending on the geographical area under study. Searches were conducted in PubMed, Cochrane Library, Web of Science and Scopus. The time frame for the analysis was from the start of the pandemic until 9th December 2021. A total of 322 papers were found. The number of articles assessed for eligibility was 32, and after applying the exclusion criteria, 13 papers were included in the qualitative synthesis. Most of the studies analysed only direct costs (69.23%) and were focused on Asia (61.54%), where the larger indirect costs, as well as the greater total costs, were found. However, the higher costs per patient and year were shown for the United States. This investigation showed the importance of COVID-19 in national, regional and local budgets. More studies are to be developed in Europe due to both the existing differences in the health care systems and financing by country and the difference in the incidence of COVID-19 by country and wave.

Food hypersensitivity: an examination of factors influencing symptoms and temporal changes in the prevalence of sensitization in an adult sample.

BACKGROUND/OBJECTIVES: Food hypersensitivity (FHS) is common, but little is known about the factors associated with severe reactions, age of onset and whether sensitization persists. This study examines the factors associated with self-reported severe food reactions, onset age and the changes in prevalence of sensitization to foods over time in an adult sample. SUBJECTS/METHODS: We used data from adults taking part in the European Community Respiratory Health Survey (ECRHS) III (2010-2014) who provided information on food hypersensitivity, including symptoms, suspected culprit food and onset age (n = 4865). A subsample from six countries had serum food-specific IgE tested for 25 core foods and also in 10 years earlier (ECRHS II). We applied logistic regression and McNemar's test for analyses. RESULTS: The prevalence of self-reported FHS was 13.5% at ECRHS III. Of those providing information on symptoms (n = 611), 26.4% reported severe reactions. About 80% of 1033 reported food-specific reactions (reported by 596 participants) began after age 15. History of asthma (odds ratio OR 2.12 95% confidence interval CI 1.13-3.44) and a younger age of onset of FHS (OR 1.02, 95% CI 1.01-1.03, per year) were associated with higher risks of a lifetime experience of severe food reactions. In the subsample with IgE tested in both surveys (n = 1612), the overall prevalence of sensitization to foods did not change over 10 years. CONCLUSION: Our findings support previous observations of more severe food reactions in people with asthma and that most FHS reported by this sample started after age 15. We found no evidence of changes in the prevalence of sensitization to food in adults followed for 10 years.

Structural basis of a redox-dependent conformational switch that regulates the stress kinase p38α.

Many functional aspects of the protein kinase p38α have been illustrated by more than three hundred structures determined in the presence of reducing agents. These structures correspond to free forms and complexes with activators, substrates, and inhibitors. Here we report the conformation of an oxidized state with an intramolecular disulfide bond between Cys119 and Cys162 that is conserved in vertebrates. The structure of the oxidized state does not affect the conformation of the catalytic site, but alters the docking groove by partially unwinding and displacing the short αD helix due to the movement of Cys119 towards Cys162. The transition between oxidized and reduced conformations provides a mechanism for fine-tuning p38α activity as a function of redox conditions, beyond its activation loop phosphorylation. Moreover, the conformational equilibrium between these redox forms reveals an unexplored cleft for p38α inhibitor design that we describe in detail.

Characterization of p38α autophosphorylation inhibitors that target the non-canonical activation pathway.

p38α is a versatile protein kinase that can control numerous processes and plays important roles in the cellular responses to stress. Dysregulation of p38α signaling has been linked to several diseases including inflammation, immune disorders and cancer, suggesting that targeting p38α could be therapeutically beneficial. Over the last two decades, numerous p38α inhibitors have been developed, which showed promising effects in pre-clinical studies but results from clinical trials have been disappointing, fueling the interest in the generation of alternative mechanisms of p38α modulation. Here, we report the in silico identification of compounds that we refer to as non-canonical p38α inhibitors (NC-p38i). By combining biochemical and structural analyses, we show that NC-p38i efficiently inhibit p38α autophosphorylation but weakly affect the activity of the canonical pathway. Our results demonstrate how the structural plasticity of p38α can be leveraged to develop therapeutic opportunities targeting a subset of the functions regulated by this pathway.

Constraints on HIV-1 evolution and immunodominance revealed in monozygotic adult twins infected with the same virus.

The predictability of virus-host interactions and disease progression in rapidly evolving human viral infections has been difficult to assess because of host and genetic viral diversity. Here we examined adaptive HIV-specific cellular and humoral immune responses and viral evolution in adult monozygotic twins simultaneously infected with the same virus. CD4 T cell counts and viral loads followed similar trajectories over three years of follow up. The initial CD8 T cell response targeted 17 epitopes, 15 of which were identical in each twin, including two immunodominant responses. By 36 months after infection, 14 of 15 initial responses were still detectable in both, whereas all new responses were subdominant and remained so. Of four responses that declined in both twins, three demonstrated mutations at the same residue. In addition, the evolving antibody responses cross-neutralized the other twin's virus, with similar changes in the pattern of evolution in the envelope gene. These results reveal considerable concordance of adaptive cellular and humoral immune responses and HIV evolution in the same genetic environment, suggesting constraints on mutational pathways to HIV immune escape.

Treatment-associated polymorphisms in protease are significantly associated with higher viral load and lower CD4 count in newly diagnosed drug-naive HIV-1 infected patients.

BACKGROUND: The effect of drug resistance transmission on disease progression in the newly infected patient is not well understood. Major drug resistance mutations severely impair viral fitness in a drug free environment, and therefore are expected to revert quickly. Compensatory mutations, often already polymorphic in wild-type viruses, do not tend to revert after transmission. While compensatory mutations increase fitness during treatment, their presence may also modulate viral fitness and virulence in absence of therapy and major resistance mutations. We previously designed a modeling technique that quantifies genotypic footprints of in vivo treatment selective pressure, including both drug resistance mutations and polymorphic compensatory mutations, through the quantitative description of a fitness landscape from virus genetic sequences. RESULTS: Genotypic correlates of viral load and CD4 cell count were evaluated in subtype B sequences from recently diagnosed treatment-naive patients enrolled in the SPREAD programme. The association of surveillance drug resistance mutations, reported compensatory mutations and fitness estimated from drug selective pressure fitness landscapes with baseline viral load and CD4 cell count was evaluated using regression techniques. Protease genotypic variability estimated to increase fitness during treatment was associated with higher viral load and lower CD4 cell counts also in treatment-naive patients, which could primarily be attributed to well-known compensatory mutations at highly polymorphic positions. By contrast, treatment-related mutations in reverse transcriptase could not explain viral load or CD4 cell count variability. CONCLUSIONS: These results suggest that polymorphic compensatory mutations in protease, reported to be selected during treatment, may improve the replicative capacity of HIV-1 even in absence of drug selective pressure or major resistance mutations. The presence of this polymorphic variation may either reflect a history of drug selective pressure, i.e. transmission from a treated patient, or merely be a result of diversity in wild-type virus. Our findings suggest that transmitted drug resistance has the potential to contribute to faster disease progression in the newly infected host and to shape the HIV-1 epidemic at a population level.