Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that can transmit through respiratory droplets, aerosols, or contacts. Frequent touching of contaminated surfaces in public areas is therefore a potential route of SARS-CoV-2 transmission. The inanimate surfaces have often been described as a source of nosocomial infections. However, summaries on the transmissibility of coronaviruses from contaminated surfaces to induce the coronavirus disease 2019 are rare at present. This review aims to summarize data on the persistence of different coronaviruses on inanimate surfaces. The literature was systematically searched on Medline without language restrictions. All reports with experimental evidence on the duration persistence of coronaviruses on any type of surface were included. Most viruses from the respiratory tract, such as coronaviruses, influenza, SARS-CoV, or rhinovirus, can persist on surfaces for a few days. Persistence time on inanimate surfaces varied from minutes to up to one month, depending on the environmental conditions. SARS-CoV-2 can be sustained in air in closed unventilated buses for at least 30 min without losing infectivity. The most common coronaviruses may well survive or persist on surfaces for up to one month. Viruses in respiratory or fecal specimens can maintain infectivity for quite a long time at room temperature. Absorbent materials like cotton are safer than unabsorbent materials for protection from virus infection. The risk of transmission via touching contaminated paper is low. Preventive strategies such as washing hands and wearing masks are critical to the control of coronavirus disease 2019.

The present study determined the role of DEP domain containing mTOR-interacting protein (DEPTOR) in the proliferation, apoptosis and chemosensitivity of RPMI-8226 multiple myeloma cells, using small hairpin RNA (shRNA) to knock down DEPTOR gene expression in vitro. DEPTOR mRNA and protein levels in RPMI-8226 cells treated with DEPTOR-specific shRNA were evaluated by reverse transcription–polymerase chain reaction and Western blotting. Expression of apoptosis-associated proteins (including cleaved caspase-3 and cleaved poly-ADP ribose polymerase [PARP]) and activation of the phosphatidylinositol 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homologue 1 (AKT) signalling pathway were detected by Western blotting. Transfection of DEPTOR-specific shRNA successfully knocked down DEPTOR gene expression in transfected RPMI-8226 cells. These transfected cells, together with control RPMI-8226 cells, were treated with 20 µmol/l melphalan for 24 h. Knockdown of DEPTOR exacerbated melphalan-induced growth inhibition and apoptosis, increased levels of cleaved caspase-3 and cleaved PARP, and reduced levels of phosphor-AKT. Downregulation of DEPTOR inhibited proliferation and increased chemosensitivity to melphalan in human multiple myeloma RPMI-8226 cells via inhibiting the PI3K/AKT pathway.

Currently, an inactivated vaccine has been widely used with encouraging results as a prophylactic agent against COVID-19 infection, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants. However, in vitro SARS-CoV-2 vaccine-specific immune features remain elusive, hindering the promotion of a third dose of the vaccine. Here, we present a detailed in vitro immune cellular response and large-scale multi-omics analysis for peripheral blood mononuclear cells (PBMCs) from participants vaccinated with CoronaVac (Sinovac Life Sciences, Beijing, China) and recovered participants from COVID-19. The mean titers of SARS-CoV-2 serum-neutralizing antibodies were significantly increased after the boosting immunization (Day 45) compared to the unimmunized state. We observed that type-1 helper T cells (Th1) tended to dominate after the first dose of vaccine, while humoral immune responses became dominant after the second dose due to the activation of type-2 helper T cell (Th2), memory B cells, and plasmablasts. T follicular helper cells (Tfh) involved in antibody production were activated after the first dose and were maintained for the observed time points. Single-cell RNA sequencing of PBMCs revealed specific changes in cell compositions and gene expression in immunized participants. Multi-omics analysis also demonstrated that CoronaVac-specific serum proteins, plasma metabolites, and plasma lipid changes were skewed to those changes in convalescent patients. Collectively, we provide a comprehensive understanding of CoronaVac-specific in vitro immune features.