ABSTRACT
In humans, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause medical complications across various tissues and organs. Despite the advances to understanding the pathogenesis of SARS-CoV-2, its tissue tropism and interactions with host cells have not been fully understood. Existing clinical data have revealed disordered calcium and phosphorus metabolism in Coronavirus Disease 2019 (COVID-19) patients, suggesting possible infection or damage in the human skeleton system by SARS-CoV-2. Herein, SARS-CoV-2 infection in mouse models with wild-type and beta strain (B.1.351) viruses is investigated, and it is found that bone marrow-derived macrophages (BMMs) can be efficiently infected in vivo. Single-cell RNA sequencing (scRNA-Seq) analyses of infected BMMs identify distinct clusters of susceptible macrophages, including those related to osteoblast differentiation. Interestingly, SARS-CoV-2 entry on BMMs is dependent on the expression of neuropilin-1 (NRP1) rather than the widely recognized receptor angiotensin-converting enzyme 2 (ACE2). The loss of NRP1 expression during BMM-to-osteoclast differentiation or NRP1 neutralization and knockdown can significantly inhibit SARS-CoV-2 infection in BMMs. Importantly, it is found that authentic SARS-CoV-2 infection impedes BMM-to-osteoclast differentiation. Collectively, this study provides evidence for NRP1-mediated SARS-CoV-2 infection in BMMs and establishes a potential link between disturbed osteoclast differentiation and disordered skeleton metabolism in COVID-19 patients.
Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Humans , Macrophages/metabolism , Mice , Neuropilin-1/genetics , Osteoclasts/metabolismABSTRACT
BACKGROUND: Rhinoviruses (RVs) cause more than half of common colds and, in some cases, more severe diseases. Functional genomics analyses of RVs using siRNA or genome-wide CRISPR screen uncovered a limited set of host factors, few of which have proven clinical relevance. RESULTS: Herein, we systematically compare genome-wide CRISPR screen and surface protein-focused CRISPR screen, referred to as surfaceome CRISPR screen, for their efficiencies in identifying RV host factors. We find that surfaceome screen outperforms the genome-wide screen in the success rate of hit identification. Importantly, using the surfaceome screen, we identify olfactomedin-like 3 (OLFML3) as a novel host factor of RV serotypes A and B, including a clinical isolate. We find that OLFML3 is a RV-inducible suppressor of the innate immune response and that OLFML3 antagonizes type I interferon (IFN) signaling in a SOCS3-dependent manner. CONCLUSION: Our study suggests that RV-induced OLFML3 expression is an important mechanism for RV to hijack the immune system and underscores surfaceome CRISPR screen in identifying viral host factors.
Subject(s)
CRISPR-Cas Systems , Glycoproteins/metabolism , Interferon Type I/antagonists & inhibitors , Rhinovirus/physiology , Genome, Human , Glycoproteins/physiology , HeLa Cells , Humans , Immunity, Innate , Signal Transduction , Suppressor of Cytokine Signaling 3 Protein/metabolism , rab5 GTP-Binding Proteins/physiologyABSTRACT
SARS-CoV-2 infection in human can cause medical complications across various tissues and organs. Despite of the advances to understanding the pathogenesis of SARS-CoV-2, its tissue tropism and interactions with host cells have not been fully understood. Existing clinical data have suggested possible SARS-CoV-2 infection in human skeleton system. In the present study, we found that authentic SARS-CoV-2 could efficiently infect human and mouse bone marrow-derived macrophages (BMMs) and alter the expression of macrophage chemotaxis and osteoclast-related genes. Importantly, in a mouse SARS-CoV-2 infection model that was enabled by the intranasal adenoviral (AdV) delivery of human angiotensin converting enzyme 2 (hACE2), SARS-CoV-2 was found to be present in femoral BMMs as determined by in situ immunofluorescence analysis. Using single-cell RNA sequencing (scRNA-Seq), we characterized SARS-CoV-2 infection in BMMs. Importantly, SARS-CoV-2 entry on BMMs appeared to be dependent on the expression of neuropilin-1 (NRP1) rather than the widely recognized receptor ACE2. It was also noted that unlike brain macrophages which displayed aging-dependent NRP1 expression, BMMs from neonatal and aged mice had constant NRP1 expression, making BMMs constantly vulnerable target cells for SARS-CoV-2. Furthermore, it was found that the abolished SARS-CoV-2 entry in BMM-derived osteoclasts was associated with the loss of NRP1 expression during BMM-to-osteoclast differentiation. Collectively, our study has suggested that NRP1 can mediate SARS-CoV-2 infection in BMMs, which precautions the potential impact of SARS-CoV-2 infection on human skeleton system.
