Single-cell analysis of adult human heart across healthy and cardiovascular disease patients reveals the cellular landscape underlying SARS-CoV-2 invasion of myocardial tissue through ACE2.

BACKGROUND: The distribution of ACE2 and accessory proteases (ANAD17 and CTSL) in cardiovascular tissue and the host cell receptor binding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are crucial to understanding the virus's cell invasion, which may play a significant role in determining the viral tropism and its clinical manifestations. METHODS: We conducted a comprehensive analysis of the cell type-specific expression of ACE2, ADAM17, and CTSL in myocardial tissue from 10 patients using RNA sequencing. Our study included a meta-analysis of 2 heart single-cell RNA-sequencing studies with a total of 90,024 cells from 250 heart samples of 10 individuals. We used co-expression analysis to locate specific cell types that SARS-CoV-2 may invade. RESULTS: Our results revealed cell-type specific associations between male gender and the expression levels of ACE2, ADAM17, and CTSL, including pericytes and fibroblasts. AGT, CALM3, PCSK5, NRP1, and LMAN were identified as potential accessory proteases that might facilitate viral invasion. Enrichment analysis highlighted the extracellular matrix interaction pathway, adherent plaque pathway, vascular smooth muscle contraction inflammatory response, and oxidative stress as potential immune pathways involved in viral infection, providing potential molecular targets for therapeutic intervention. We also found specific high expression of IFITM3 and AGT in pericytes and differences in the IFN-II signaling pathway and PAR signaling pathway in fibroblasts from different cardiovascular comorbidities. CONCLUSIONS: Our data indicated possible high-risk groups for COVID-19 and provided emerging avenues for future investigations of its pathogenesis. TRIAL REGISTRATION: (Not applicable).

COVID-19 vaccination status, side effects, and perceptions among breast cancer survivors: a cross-sectional study in China.

Introduction: Breast cancer is the most prevalent malignancy in patients with coronavirus disease 2019 (COVID-19). However, vaccination data of this population are limited. Methods: A cross-sectional study of COVID-19 vaccination was conducted in China. Multivariate logistic regression models were used to assess factors associated with COVID-19 vaccination status. Results: Of 2,904 participants, 50.2% were vaccinated with acceptable side effects. Most of the participants received inactivated virus vaccines. The most common reason for vaccination was "fear of infection" (56.2%) and "workplace/government requirement" (33.1%). While the most common reason for nonvaccination was "worry that vaccines cause breast cancer progression or interfere with treatment" (72.9%) and "have concerns about side effects or safety" (39.6%). Patients who were employed (odds ratio, OR = 1.783, p = 0.015), had stage I disease at diagnosis (OR = 2.008, p = 0.019), thought vaccines could provide protection (OR = 1.774, p = 0.007), thought COVID-19 vaccines were safe, very safe, not safe, and very unsafe (OR = 2.074, p < 0.001; OR = 4.251, p < 0.001; OR = 2.075, p = 0.011; OR = 5.609, p = 0.003, respectively) were more likely to receive vaccination. Patients who were 1-3 years, 3-5 years, and more than 5 years after surgery (OR = 0.277, p < 0.001; OR = 0.277, p < 0.001, OR = 0.282, p < 0.001, respectively), had a history of food or drug allergies (OR = 0.579, p = 0.001), had recently undergone endocrine therapy (OR = 0.531, p < 0.001) were less likely to receive vaccination. Conclusion: COVID-19 vaccination gap exists in breast cancer survivors, which could be filled by raising awareness and increasing confidence in vaccine safety during cancer treatment, particularly for the unemployed individuals.

Discovery of novel Mamastroviruses in Bactrian camels and dromedaries reveals complex recombination history.

Virus emergence may occur through interspecies transmission and recombination of viruses coinfecting a host, with potential to pair novel and adaptive gene combinations. Camels are known to harbor diverse ribonucleic acid viruses with zoonotic and epizootic potential. Among them, astroviruses are of particular interest due to their cross-species transmission potential and endemicity in diverse host species, including humans. We conducted a molecular epidemiological survey of astroviruses in dromedaries from Saudi Arabia and Bactrian camels from Inner Mongolia, China. Herein, we deployed a hybrid sequencing approach coupling deep sequencing with rapid amplification of complementary deoxyribonucleic acid ends to characterize two novel Bactrian and eight dromedary camel astroviruses, including both partial and complete genomes. Our reported sequences expand the known diversity of dromedary camel astroviruses, highlighting potential recombination events among the astroviruses of camelids and other host species. In Bactrian camels, we detected partially conserved gene regions bearing resemblance to human astrovirus types 1, 4, and 8 although we were unable to recover complete reading frames from these samples. Continued surveillance of astroviruses in camelids, particularly Bactrian species and associated livestock, is highly recommended to identify patterns of cross-species transmission and to determine any epizootic threats and zoonotic risks posed to humans. Phylogenomic approaches are needed to investigate complex patterns of recombination among the astroviruses and to infer their evolutionary history across diverse host species.

Manganese-coordinated mRNA vaccines with enhanced mRNA expression and immunogenicity induce robust immune responses against SARS-CoV-2 variants.

It is urgent to develop more effective mRNA vaccines against the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants owing to the immune escape. Here, we constructed a novel mRNA delivery system [IC8/Mn lipid nanoparticles (IC8/Mn LNPs)]with high immunogenicity, via introducing a stimulator of interferon genes (STING) agonist [manganese (Mn)] based on a newly synthesized ionizable lipid (IC8). It was found that Mn can not only promote maturation of antigen-presenting cells via activating STING pathway but also improve mRNA expression by facilitating lysosomal escape for the first time. Subsequently, IC8/Mn LNPs loaded with mRNA encoding the Spike protein of SARS-CoV-2 Delta or Omicron variant (IC8/Mn@D or IC8/Mn@O) were prepared. Both mRNA vaccines induced substantial specific immunoglobulin G responses against Delta or Omicron. IC8/Mn@D displayed strong pseudovirus neutralization ability, T helper 1-biased immune responses, and good safety. It can be concluded that IC8/Mn LNPs have great potential for developing Mn-coordinated mRNA vaccines with robust immunogenicity and good safety.

Booster shot of inactivated SARS-CoV-2 vaccine induces potent immune responses in people living with HIV.

This study aimed to investigate the immunogenicity to SARS-CoV-2 and evasive subvariants BA.4/5 in people living with HIV (PLWH) following a third booster shot of inactivated SARS-CoV-2 vaccine. We conducted a cross-sectional study in 318 PLWH and 241 healthy controls (HC) using SARS-CoV-2 immunoassays. Vaccine-induced immunological responses were compared before and after the third dose. Serum levels of IgG anti-RBD and inhibition rate of NAb were significantly elevated at the "post-third dose" sampling time compared with the pre-third dose in PLWH, but were relatively decreased in contrast with those of HCs. Induced humoral and cellular responses attenuated over time after triple-dose vaccination. The neutralizing capacity against BA.4/5 was also intensified but remained below the positive inhibition threshold. Seropositivity of SARS-CoV-2-specific antibodies in PLWH was prominently lower than that in HC. We also identified age, CD4 cell counts, time after the last vaccination, and WHO staging type of PLWH as independent factors associated with the seropositivity of antibodies. PLWH receiving booster shot of inactivated vaccines generate higher antibody responses than the second dose, but lower than that in HCs. Decreased anti-BA.4/5 responses than that of WT impede the protective effect of the third dose on Omicron prevalence.

Roles of biomarkers in anti-MDA5-positive dermatomyositis, associated interstitial lung disease, and rapidly progressive interstitial lung disease.

BACKGROUND: Anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (MDA5+ DM) is significantly associated with interstitial lung disease (ILD), especially rapidly progressive ILD (RPILD) due to poor prognosis, resulting in high mortality rates. However, the pathogenic mechanism of MDA5+ DM-RPILD is unclear. Although some MDA5+ DM patients have a chronic course of ILD, many do not develop RPILD. Therefore, the related biomarkers for the early diagnosis, disease activity monitoring, and prediction of the outcome of RPILD in MDA5+ DM patients should be identified. Blood-based biomarkers are minimally invasive and can be easily detected. METHODS: Recent relative studies related to blood biomarkers in PubMed were reviewed. RESULTS: An increasing number of studies have demonstrated that dysregulated expression of blood biomarkers related to ILD such as ferritin, Krebs von den Lungen-6 (KL-6), surfactant protein-D (SP-D), and cytokines, and some tumor markers in MDA5+ DM may provide information in disease presence, activity, treatment response, and prognosis. These studies have highlighted the great potentials of blood biomarker values for MDA5+ DM-ILD and MDA5+ DM-RPILD. This review provides an overview of recent studies related to blood biomarkers, besides highlighted protein biomarkers, including antibody (anti-MDA5 IgG subclasses and anti-Ro52 antibody), genetic (exosomal microRNAs and neutrophil extracellular traps related to cell-free DNA), and immune cellular biomarkers in MDA5+ DM, MDA5+ DM-ILD, and MDA5+ DM-RPILD patients, hopefully elucidating the pathogenesis of MDA5+ DM-ILD and providing information on the early diagnosis, disease activity monitoring, and prediction of the outcome of the ILD, especially RPILD. CONCLUSIONS: Therefore, this review may provide insight to guide treatment decisions for MDA5+ DM-RPILD patients and improve outcomes.

mRNA Vaccines Against SARS‐CoV‐2 Variants Delivered by Lipid Nanoparticles Based on Novel Ionizable Lipids

SARS‐CoV‐2 variants are now still challenging all the approved vaccines, including mRNA vaccines. There is an urgent need to develop new generation mRNA vaccines with more powerful efficacy and better safety against SARS‐CoV‐2 variants. In this study, a new set of ionizable lipids named 4N4T are constructed and applied to form novel lipid nanoparticles called 4N4T‐LNPs. Leading 4N4T‐LNPs exhibit much higher mRNA translation efficiency than the approved SM‐102‐LNPs. To test the effectiveness of the novel delivery system, the DS mRNA encoding the full‐length S protein of the SARS‐CoV‐2 variant is synthesized and loaded in 4N4T‐LNPs. The obtained 4N4T‐DS mRNA vaccines successfully trigger robust and durable humoral immune responses against SARS‐CoV‐2 and its variants including Delta and Omicron. Importantly, the novel vaccines have higher RBD‐specific IgG titers and neutralizing antibody titers than SM‐102‐based DS mRNA vaccine. Besides, for the first time, the types of mRNA vaccine‐induced neutralizing antibodies are found to be influenced by the chemical structure of ionizable lipids. 4N4T‐DS mRNA vaccines also induce strong Th1‐skewed T cell responses and have good safety. This work provides a novel vehicle for mRNA delivery that is more effective than the approved LNPs and shows its application in vaccines against SARS‐CoV‐2 variants. In this study, mRNA vaccines against SARS‐CoV‐2 variants delivered by lipid nanoparticles based on 4N4T lipids are constructed, and successfully trigger robust and durable humoral immune responses against SARS‐CoV‐2 and its variants including Delta and Omicron. In addition, head‐to‐head comparison studies find that the novel 4N4T lipids have a higher mRNA delivery efficiency than SM‐102.