High-dimensional analysis of 16 SARS-CoV-2 vaccine combinations reveals lymphocyte signatures correlating with immunogenicity.

The range of vaccines developed against severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) provides a unique opportunity to study immunization across different platforms. In a single-center cohort, we analyzed the humoral and cellular immune compartments following five coronavirus disease 2019 (COVID-19) vaccines spanning three technologies (adenoviral, mRNA and inactivated virus) administered in 16 combinations. For adenoviral and inactivated-virus vaccines, heterologous combinations were generally more immunogenic compared to homologous regimens. The mRNA vaccine as the second dose resulted in the strongest antibody response and induced the highest frequency of spike-binding memory B cells irrespective of the priming vaccine. Priming with the inactivated-virus vaccine increased the SARS-CoV-2-specific T cell response, whereas boosting did not. Distinct immune signatures were elicited by the different vaccine combinations, demonstrating that the immune response is shaped by the type of vaccines applied and the order in which they are delivered. These data provide a framework for improving future vaccine strategies against pathogens and cancer.

N6-methyladenosine in poly(A) tails stabilize VSG transcripts.

RNA modifications are important regulators of gene expression1. In Trypanosoma brucei, transcription is polycistronic and thus most regulation happens post-transcriptionally2. N6-methyladenosine (m6A) has been detected in this parasite, but its function remains unknown3. Here we found that m6A is enriched in 342 transcripts using RNA immunoprecipitation, with an enrichment in transcripts encoding variant surface glycoproteins (VSGs). Approximately 50% of the m6A is located in the poly(A) tail of the actively expressed VSG transcripts. m6A residues are removed from the VSG poly(A) tail before deadenylation and mRNA degradation. Computational analysis revealed an association between m6A in the poly(A) tail and a 16-mer motif in the 3' untranslated region of VSG genes. Using genetic tools, we show that the 16-mer motif acts as a cis-acting motif that is required for inclusion of m6A in the poly(A) tail. Removal of this motif from the 3' untranslated region of VSG genes results in poly(A) tails lacking m6A, rapid deadenylation and mRNA degradation. To our knowledge, this is the first identification of an RNA modification in the poly(A) tail of any eukaryote, uncovering a post-transcriptional mechanism of gene regulation.

Acute Hepatitis in Children Due to Rat Hepatitis E Virus.

Two of 11 children with acute hepatitis of unknown origin were found to have rat hepatitis E virus infection. This infection should be considered in the differential diagnosis of children with acute hepatitis of unknown origin.

Targeting MDM2 enhances antileukemia immunity after allogeneic transplantation via MHC-II and TRAIL-R1/2 upregulation.

Patients with acute myeloid leukemia (AML) often achieve remission after allogeneic hematopoietic cell transplantation (allo-HCT) but subsequently die of relapse driven by leukemia cells resistant to elimination by allogeneic T cells based on decreased major histocompatibility complex II (MHC-II) expression and apoptosis resistance. Here we demonstrate that mouse-double-minute-2 (MDM2) inhibition can counteract immune evasion of AML. MDM2 inhibition induced MHC class I and II expression in murine and human AML cells. Using xenografts of human AML and syngeneic mouse models of leukemia, we show that MDM2 inhibition enhanced cytotoxicity against leukemia cells and improved survival. MDM2 inhibition also led to increases in tumor necrosis factor-related apoptosis-inducing ligand receptor-1 and -2 (TRAIL-R1/2) on leukemia cells and higher frequencies of CD8+CD27lowPD-1lowTIM-3low T cells, with features of cytotoxicity (perforin+CD107a+TRAIL+) and longevity (bcl-2+IL-7R+). CD8+ T cells isolated from leukemia-bearing MDM2 inhibitor-treated allo-HCT recipients exhibited higher glycolytic activity and enrichment for nucleotides and their precursors compared with vehicle control subjects. T cells isolated from MDM2 inhibitor-treated AML-bearing mice eradicated leukemia in secondary AML-bearing recipients. Mechanistically, the MDM2 inhibitor-mediated effects were p53-dependent because p53 knockdown abolished TRAIL-R1/2 and MHC-II upregulation, whereas p53 binding to TRAILR1/2 promotors increased upon MDM2 inhibition. The observations in the mouse models were complemented by data from human individuals. Patient-derived AML cells exhibited increased TRAIL-R1/2 and MHC-II expression on MDM2 inhibition. In summary, we identified a targetable vulnerability of AML cells to allogeneic T-cell-mediated cytotoxicity through the restoration of p53-dependent TRAIL-R1/2 and MHC-II production via MDM2 inhibition.

MicroRNA-181a restricts human γδ T cell differentiation by targeting Map3k2 and Notch2.

γδ T cells are a conserved population of lymphocytes that contributes to anti-tumor responses through its overt type 1 inflammatory and cytotoxic properties. We have previously shown that human γδ T cells acquire this profile upon stimulation with IL-2 or IL-15, in a differentiation process dependent on MAPK/ERK signaling. Here, we identify microRNA-181a as a key modulator of human γδ T cell differentiation. We observe that miR-181a is highly expressed in patients with prostate cancer and that this pattern associates with lower expression of NKG2D, a critical mediator of cancer surveillance. Interestingly, miR-181a expression negatively correlates with an activated type 1 effector profile obtained from in vitro differentiated γδ T cells and miR-181a overexpression restricts their levels of NKG2D and TNF-α. Upon in silico analysis, we identify two miR-181a candidate targets, Map3k2 and Notch2, which we validate via overexpression coupled with luciferase assays. These results reveal a novel role for miR-181a as critical regulator of human γδ T cell differentiation and highlight its potential for manipulation of γδ T cells in next-generation immunotherapies.

Genetic profile of syndromic retinitis pigmentosa in Portugal.

PURPOSE: Retinitis pigmentosa (RP) comprises a genetically and clinically heterogeneous group of inherited retinal degenerations, where 20-30% of patients exhibit extra-ocular manifestations (syndromic RP). Understanding the genetic profile of RP has important implications for disease prognosis and genetic counseling. This study aimed to characterize the genetic profile of syndromic RP in Portugal. METHODS: Multicenter, retrospective cohort study. Six Portuguese healthcare providers identified patients with a clinical diagnosis of syndromic RP and available genetic testing results. All patients had been previously subjected to a detailed ophthalmologic examination and clinically oriented genetic testing. Genetic variants were classified according to the American College of Medical Genetics and Genomics; only likely pathogenic or pathogenic variants were considered relevant for disease etiology. RESULTS: One hundred and twenty-two patients (53.3% males) from 100 families were included. Usher syndrome was the most frequent diagnosis (62.0%), followed by Bardet-Biedl (19.0%) and Senior-Løken syndromes (7.0%). Deleterious variants were identified in 86/100 families for a diagnostic yield of 86.0% (87.1% for Usher and 94.7% for Bardet-Biedl). A total of 81 genetic variants were identified in 25 different genes, 22 of which are novel. USH2A and MYO7A were responsible for most type II and type I Usher syndrome cases, respectively. BBS1 variants were the cause of Bardet-Biedl syndrome in 52.6% of families. Best-corrected visual acuity (BCVA) records were available at baseline and last visit for 99 patients (198 eyes), with a median follow-up of 62.0 months. The mean BCVA was 56.5 ETDRS letters at baseline (Snellen equivalent ~ 20/80), declining to 44.9 ETDRS letters (Snellen equivalent ~ 20/125) at the last available follow-up (p < 0.001). CONCLUSION: This is the first multicenter study depicting the genetic profile of syndromic RP in Portugal, thus contributing toward a better understanding of this heterogeneous disease group. Usher and Bardet-Biedl syndromes were found to be the most common types of syndromic RP in this large Portuguese cohort. A high diagnostic yield was obtained, highlighting current genetic testing capabilities in providing a molecular diagnosis to most affected individuals. This has major implications in determining disease-related prognosis and providing targeted genetic counseling for syndromic RP patients in Portugal.

Is there an association between proficiency in fundamental movement skills and mderate-to-vigorous physical activity in childhood on weekdays and weekends? The REACT project.

OBJECTIVE: The present study probes into the association between children's fundamental movement skills (FMS) and moderate-to-vigorous physical activity (MVPA) during weekdays and weekends. METHODS: This cross-sectional sample included 1014 children aged 6-10 years from the REACT project. Physical activity was assessed with accelerometry, and five FMS (stationary dribble, kick, catch, overhand throw, and underhand roll) were assessed with the digital platform Meu Educativo®. Three groups were formed based on the frequency of FMS that each child mastered: group 1 (wizard level in four or five FMS); group 2 (wizard level in two or three FMS); and group 3 (wizard level in at most one skill). Multilevel models were used to analyze the data treating children (level-1) nested within schools (level-2). RESULTS: Compared to group 1, groups 2 (-12.9 ± 2.3 min day-1) and 3 (-23.9 ± 2.4 min day-1) were less physically active during weekdays and weekends (group 2: -14.7 ± 2.7 min day-1 and group 3: -22.4 ± 2.9 min day-1), independent of age and sex. There was a decline in MVPA during the weekend. Further, on average, boys were more active than girls, and with increasing age, children were less active. CONCLUSION: On average, children with higher FMS levels are generally more physically active than their peers with lower FMS levels. Even though MVPA tends to decline on weekends, FMS proficiency is a significant factor in maintaining 60 min of MVPA on weekends.

A multivariate multilevel approach to unravel the associations between individual and school factors on children's motor performance in the REACT project.

OBJECTIVE: The aim was to (1) estimate the relationship between physical fitness (PF) and object control fundamental movement skills (FMS), (2) identify child characteristics that relate with PF and FMS, and (3) examine associations between the school environment, PF, and FMS. METHODS: The sample included 1014 Portuguese children aged 6-10 years from the REACT project. PF was assessed via running speed, shuttle run, standing long jump, handgrip, and the PACER test. Object control FMS were assessed with stationary dribble, kick, catch, overhand throw, and underhand roll. Test performances were transformed into z-scores, and their sum was expressed as overall PF and FMS. Child-level variables included body mass index (BMI) z-scores, accelerometer-measured sedentary time and moderate-to-vigorous physical activity, and socioeconomic status (SES). School size, physical education classes, practice areas, and equipment were also assessed. RESULTS: Approximately, 90% of the variance in object control PF and FMS was at the child level, and 10% at the school level. The correlation between PF and object control FMS was .62, which declined to .43 with the inclusion of covariates. Older, more active, and higher SES children had higher object control PF and FMS, and boys outperformed girls. BMI was negatively associated with PF but not with object control FMS. Sedentary time and number of physical education classes were not significant predictors. Most school predictors did not jointly associate with PF and object control FMS. CONCLUSION: PF and object control FMS z-scores were moderately related. Not all child characteristics were associated with both PF and object control FMS, and their effect sizes were different. School characteristics only explained 10% of the total variation in PF and object control FMS.

Individual and school correlates of body mass index and cardiorespiratory fitness in primary school children from the REACT project: A multivariate multilevel analysis.

OBJECTIVE: This paper examines the relationship between body mass index (BMI) and cardiorespiratory fitness (CRF) using a multivariate multilevel approach and investigates the links between individual and school-related correlates with children's BMI and CRF. METHODS: This cross-sectional sample included 1014 children (6-10 years) from 25 Portuguese primary schools. BMI was calculated, and CRF was assessed with the PACER test. Fundamental movement skills (FMS) included five object control tasks. Moderate-to-vigorous physical activity (MVPA), sleep, and sedentary time were assessed with the ActiGraph wGT3X-BT accelerometer. Socioeconomic status (SES) and school variables were also obtained. A multivariate multilevel model was used, and alpha was set at 5%. RESULTS: BMI and CRF systematically increased with age. Most of the joint variance (94.4%) was explained at the child level, and BMI and CRF were correlated at this level (ρ = -.37). More active children demonstrated higher CRF levels and had lower BMI levels; sedentary and sleep time were not significantly associated with BMI or CRF. FMS were positively associated with CRF but were not significantly associated with BMI. Children at higher SES were more fit and had lower BMI than their peers of lower SES. Finally, school-level variables were not significantly related to BMI and CRF. CONCLUSION: BMI and CRF had a low but statistically significant negative correlation in this sample of children. Most of the variation in BMI and CRF was explained by child-level characteristics.

Associations of obesity, movement behaviors, and socioeconomic status with fundamental movement skills in children: Results from the REACT project.

OBJECTIVE: To investigate the relationship of biological characteristics (age, sex, and obesity), movement behaviors (physical activity and sedentary time), and family socioeconomic status with fundamental movement skills (FMS) in primary school children. METHODS: This cross-sectional study sampled 1014 children (537 girls) aged 6 to 10 years from 25 primary schools in Matosinhos, north of Portugal. Five object control skills (dribbling, kicking, catching, throwing, and underarm rolling) were assessed with a categorical scale using the Meu Educativo® platform. Body Mass Index (BMI) was calculated and transformed into z-scores. Moderate-to-vigorous physical activity (MVPA) and sedentary time were monitored with accelerometry (ActiGraph wGT3X-BT) for seven consecutive days. Family socioeconomic status (SES) was obtained from the Portuguese social support system. Ordinal multilevel logistic regression was used to analyze the associations of weight status, MVPA, sedentary time and SES with FMS, adjusted for sex and age. RESULTS: Boys (odds ratio (OR) = 6.54; 95% CI: 5.13-8.36) and older children (OR = 2.04; 95% CI: 1.85-2.26) were more likely to achieve higher FMS scores. Children with obesity (OR = 0.60; 95% CI: 0.45-0.80), those less active (OR = 0.56; 95% CI: 0.42-0.75) and children with more sedentary time (OR = 0.86; 95%CI: 0.77-0.97) were less likely to score high on FMS. Family SES was not significantly associated with FMS scores. CONCLUSION: Primary school children's FMS are significantly related to biological and behavioral factors but not to family SES. These findings highlight the need for suitable strategies to enhance children's FMS proficiency, considering differences in these characteristics. Fostering adequate motor skill proficiency levels will assist in establishing a robust foundation for healthy lifestyles of all children.

Febrile ulceronecrotic Mucha-Habermann disease - a case and treatment review.

Febrile ulceronecrotic Mucha-Habermann disease is a rare and severe variant of pityriasis lichenoides, characterized by sudden onset of generalized ulceronecrotic papules that rapidly coalesce into ulcers associated with high fever. Systemic manifestations such as intravascular disseminated coagulation and pulmonary, cardiac, gastrointestinal, and central nervous system involvement are common. Treatment is based on oral corticosteroids, immunosuppressive drugs such as methotrexate, and general supportive treatment. The present case describes a stepwise approach to a patient with Mucha-Habermann disease with insufficient response to methotrexate.

Phase II trial of hypomethylating agent combined with nivolumab for acute myeloid leukaemia relapse after allogeneic haematopoietic cell transplantation-Immune signature correlates with response.

Acute myeloid leukaemia (AML) relapse after allogeneic haematopoietic cell transplantation (allo-HCT) is often driven by immune-related mechanisms and associated with poor prognosis. Immune checkpoint inhibitors combined with hypomethylating agents (HMA) may restore or enhance the graft-versus-leukaemia effect. Still, data about using this combination regimen after allo-HCT are limited. We conducted a prospective, phase II, open-label, single-arm study in which we treated patients with haematological AML relapse after allo-HCT with HMA plus the anti-PD-1 antibody nivolumab. The response was correlated with DNA-, RNA- and protein-based single-cell technology assessments to identify biomarkers associated with therapeutic efficacy. Sixteen patients received a median number of 2 (range 1-7) nivolumab applications. The overall response rate (CR/PR) at day 42 was 25%, and another 25% of the patients achieved stable disease. The median overall survival was 15.6 months. High-parametric cytometry documented a higher frequency of activated (ICOS+ , HLA-DR+ ), low senescence (KLRG1- , CD57- ) CD8+ effector T cells in responders. We confirmed these findings in a preclinical model. Single-cell transcriptomics revealed a pro-inflammatory rewiring of the expression profile of T and myeloid cells in responders. In summary, the study indicates that the post-allo-HCT HMA/nivolumab combination induces anti-AML immune responses in selected patients and could be considered as a bridging approach to a second allo-HCT. Trial-registration: EudraCT-No. 2017-002194-18.

Proteostasis networks in aging: novel insights from text-mining approaches.

Aging is a topic of paramount importance in an increasingly elderly society and has been the focus of extensive research. Protein homeostasis (proteostasis) decline is a hallmark in aging and several age-related diseases, but which specific proteins and mechanisms are involved in proteostasis (de)regulation during the aging process remain largely unknown. Here, we used different text-mining tools complemented with protein-protein interaction data to address this complex topic. Analysis of the integrated protein interaction networks identified novel proteins and pathways associated to proteostasis mechanisms and aging or age-related disorders, indicating that this approach is useful to identify previously unknown links and for retrieving information of potential novel biomarkers or therapeutic targets.

Validity and reliability of Meu Educativo®: A new tool to assess fundamental movement skills in school-aged children.

OBJECTIVES: There is evidence showing that children's proficiency in fundamental movement skills (FMS) is positively related to weight status, physical activity, fitness levels, cognitive development, as well as academic performance. Yet, the feasibility of FMS assessment is challenging, especially with relatively large samples of children. This article presents a new tool named Meu Educativo® to assess children's FMS levels, including its validity and reliability. METHODS: We relied on the validity evidence approach based on test content to develop the FMS assessment checklist and the rating system with a team of experts. In this article, we used five FMS (stationary dribbling, kick, overhand throw, catch the ball, and underhand roll). Further, we conducted a series of reliability studies and used percent agreement and Cohen's kappa (κ) as statistics. RESULTS: Experts agreed highly on the checklist's components in the five FMS. Inter-rater reliability ranged from 0.63 for stationary dribbling to 0.93 for overhand throw, and the intra-rater reliability ranged from 0.46 to 0.94. CONCLUSION: Based on the first results, Meu Educativo® was not only easy to use, but was also a reliable tool for FMS assessments. Notwithstanding the need for future studies, Meu Educativo® is a new tool that can be used by teachers, coaches, and motor development specialists dealing with school-aged children and researchers working with large samples.

Background, rationale, and methodological overview of the REACT project-return-to-action on growth, motor development, and health after the COVID-19 pandemic in primary school children.

OBJECTIVES: The REACT project was designed around two main aims: (1) to assess children's growth and motor development after the COVID-19 pandemic and (2) to follow their fundamental movement skills' developmental trajectories over 18 months using a novel technological device (Meu Educativo®) in their physical education classes. In this introductory article, the first of the Journal's special issue dedicated to REACT, our goal was to present the project rationale, its methodology, training and certification of the team, statistical approach, quality control, governance, and study management. METHODS: We sampled 1000 children (6-10 years of age) from 25 of the 32 primary schools in Matosinhos, northern Portugal. The protocol included a set of variables clustered around the child (growth, physical fitness, fundamental movement skills, and health behaviors), family (demographics, socioeconomic status, parental support for sports participation and physical activity), school (policies and practices for health behaviors, infrastructure for physical education and sports practices), and neighborhood and home environments (safety, sidewalks, sports facilities, as well as children electronic devices and play equipment at home). A set of standard protocols were implemented in REACT together with a rigorous system of training and certification of all members of the research team. This was complemented with a pilot study to assess, in loco, the quality of data acquisition, data entry, and control. DISCUSSION: Results from REACT will provide school administrators and teachers with novel and far-reaching information related to children's growth and motor development as well as health behaviors after the COVID-19 pandemic. It will also provide city-hall education officials with insight regarding children's physical fitness, fundamental movement skills, and sports practices that will be of great importance in devising novel intervention programs to increase health-enhancing physical activity, and combat sedentariness and obesity. Finally, it will offer parents a wealth of information regarding their children's growth, motor development, and health.

Statistical analysis of the longitudinal fundamental movement skills data in the REACT project using the multilevel ordinal logistic model.

OBJECTIVES: The REACT project was designed around two main aims: (1) to assess children's growth and motor development after the COVID-19 pandemic and (2) to follow their fundamental movement skills' developmental trajectories over 18 months using a novel technological device (Meu Educativo®) in their physical education classes. In this article, our goal is to describe statistical analysis of the longitudinal ordinal motor development data that was obtained from these children using the multilevel ordinal logistic model. METHODS: Longitudinal ordinal data are often collected in studies on motor development. For example, children or adolescents might be rated as having poor, good, or excellent performance levels in fundamental movement skills, and such ratings may be obtained yearly over time to assess changes in fundamental movement skills levels of performance. However, such longitudinal ordinal data are often analyzed using either methods for continuous outcomes, or by dichotomizing the ordinal outcome and using methods for binary data. These approaches are not optimal, and so we describe in detail the use of the multilevel ordinal logistic model for analysis of such data from the REACT project. Our intent is to provide an accessible description and application of this model for analysis of ordinal motor development data. DISCUSSION: Our analyses show both the between-subjects and within-subjects effects of age on motor development outcomes across three timepoints. The between-subjects effect of age indicate that children that are older have higher motor development ratings, relative to thoese that are younger, whereas the within-subject effect of age indicates higher motor development ratings as a child ages. It is the latter effect that is particularly of interest in longitudinal studies of motor development, and an important advantage of using the multilevel ordinal logistic model relative to more traditional methods.

Sleep and fundamental movement skills in primary schoolchildren: The REACT project.

OBJECTIVE: Whether sleep is related to fundamental movement skills (FMS) in the pediatric population is largely unknown. The objective of this study was to examine the association between sleep characteristics (duration, efficiency, regularity) and FMS proficiency levels in school-aged children. METHODS: This cross-sectional study included 996 children (mean age: 8.3 ± 1.2 years) from 25 of the 32 primary schools in Matosinhos, northern Portugal. Data collection occurred between January and June 2022. Sleep was assessed using an ActiGraph wGT3X-BT accelerometer worn on the wrist for 7 consecutive days. FMS proficiency levels were assessed in the schools with a new digital platform (Meu Educativo®) that evaluated five object control skills (dribble, kick, catch, throw, and underhand roll), with a total score ranging between 5 and 15. Multilevel ordinal logistic regression was used to test the associations between sleep characteristics and FMS proficiency levels. Covariates included age, sex, body mass index z-score, socioeconomic status, and moderate-to-vigorous physical activity. RESULTS: The results showed that sleep characteristics (duration, efficiency, and regularity) were not related to FMS proficiency. Being a boy, older age, and higher moderate-to-vigorous physical activity levels were all significantly associated with better FMS proficiency levels. There were no significant sex-by-age interactions. CONCLUSION: Sleep was not found to be related to FMS performance in children. This finding suggests that sleep is not a good correlate of FMS proficiency levels in school-aged children, and attention should be dedicated to other more important factors such as skill-learning-specific physical activity.

Hyperoside Supplementation in Preservation Media Surpasses Vitamin C Protection Against Oxidative Stress-Induced Damages in Human Spermatozoa.

BACKGROUND/AIMS: Oxidative Stress (OS) is reported as one of the main causes of male infertility. Infertile couples often resort to assisted reproductive technology (ART) to achieve parenthood. However, preparation for ART protocols increases the exposer of gametes to OS. Thus, it is crucial to find suitable preservation media that can counteract the OS-induced damages in spermatozoa. In this work, we tested and compared the efficiency of vitamin C (VC) and hyperoside (HYP) as potential antioxidant supplements for sperm preservation media. METHODS: We evaluated the cytotoxicity of HYP (0, 5, 50, 100, and 500 µM) in spermatozoa. After incubation of sperm cells with VC (600 µM) and HYP (100 and 500 µM), in the presence and absence of H2O2 (300 µM), the following parameters were assessed: total sperm motility and vitality, OS biomarkers expression, total antioxidant capacity (TAC) of the media, percentage of DNA fragmentation, mitochondrial membrane potential (MMP), and metabolite quantification of the media by proton nuclear magnetic resonance (1H-NMR). RESULTS: The supplementation with VC (600 µM) and HYP (100 and 500 µM) did not induce any deleterious effects to the physiology and metabolism of the spermatozoa, after 1-hour of treatment. In the presence of H2O2 (300 µM), both VC and HYP were able to prevent some of the deleterious effects of H2O2 in sperm, which were represented by an increase in sperm motility, a decrease in DNA fragmentation, and a decreasing trend in lipid peroxidation levels. However, these antioxidants were not able to prevent the decrease of MMP associated with H2O2 treatment, nor were able to prevent the conversion of pyruvate into acetate (a reaction promoted by H2O2). CONCLUSION: The supplementation of sperm preservation media with VC and HYP could be beneficial for the preservation of sperm physiology. From the antioxidant conditions tested, the supplementation of media with HYP (100 µM) demonstrated the best results regarding sperm preservation, evidencing the higher antioxidant capacity of HYP compared to VC. Nevertheless, none of the antioxidants used was able to prevent the metabolic alterations promoted by H2O2 in spermatozoa.

Mechanistic Studies of an Automated Lipid Nanoparticle Reveal Critical Pharmaceutical Properties Associated with Enhanced mRNA Functional Delivery In Vitro and In Vivo.

Recently, lipid nanoparticles (LNPs) have attracted attention due to their emergent use for COVID-19 mRNA vaccines. The success of LNPs can be attributed to ionizable lipids, which enable functional intracellular delivery. Previously, the authors established an automated high-throughput platform to screen ionizable lipids and identified that the LNPs generated using this automated technique show comparable or increased mRNA functional delivery in vitro as compared to LNPs prepared using traditional microfluidics techniques. In this study, the authors choose one benchmark lipid, DLin-MC3-DMA (MC3), and investigate whether the automated formulation technique can enhance mRNA functional delivery in vivo. Interestingly, a 4.5-fold improvement in mRNA functional delivery in vivo by automated LNPs as compared to LNPs formulated by conventional microfluidics techniques, is observed. Mechanistic studies reveal that particles with large size accommodate more mRNA per LNP, possess more hydrophobic surface, are more hemolytic, bind a larger protein corona, and tend to accumulate more in macropinocytosomes, which may quantitatively benefit mRNA cytosolic delivery. These data suggest that mRNA loading per particle is a critical factor that accounts for the enhanced mRNA functional delivery of automated LNPs. These mechanistic findings provide valuable insight underlying the enhanced mRNA functional delivery to accelerate future mRNA LNP product development.

Sibling Resemblances in Physical Fitness in Three Distinct Regions in Peru: The Peruvian Sibling Study on Growth and Health.

We estimated sibling resemblance in health-related physical fitness (PF) and examined how individual characteristics and shared natural environment accounted for sibling similarities. The sample comprised 656 sibling pairs and 102 triplets (6-15 years of age), from three geographical areas of Peru. PF components included morphological (waist circumference, sum of skinfolds), muscular (handgrip strength, standing long jump), and motor (shuttle-run). Body mass index (BMI) and somatic maturation were also assessed. In general, sibling intraclass correlations differed significantly across sib-ship types for waist circumference and handgrip strength but were the same for sum of skinfolds, standing long jump, and shuttle-run. Further, in general, both individual characteristics and geographical area of residence significantly influenced the magnitude of sibling resemblance as well as the mean levels of PF. In conclusion, individual characteristics and shared natural environment jointly influenced the expression of PF in Peruvian siblings, revealing the importance of these features when designing individualized programs promoting fitness.