RNA-sequencing unravels unique host-response to infection with SARS-CoV-2

Introduction/Aim: As the causative agent of COVID-19, SARS-CoV-2 remains a global cause for concern. Compared to other highly pathogenic coronaviruses (SARS-CoV and MERS-CoV), SARS-CoV-2 exhibits stronger transmissibility but less lethality, indicating that SARS-CoV-2 displays unique characteristics, despite the partial genomic proximity. Thus, we aim to employ RNA sequencing to define transcriptional differences in epithelial responses following infection with SARS-CoV-2 compared to pathogenic SARS-CoV and MERS-CoV, and low pathogenic HCoV-229E. Method(s): Primary human bronchial epithelial cells (PBEC) were differentiated for 6 weeks at the air-liquid interface (ALI) before parallel infection by the 4 different coronaviruses (n = 4). After infection following apical application of coronaviruses at low dose (MOI 0.1), cells were harvested for bulk RNA sequencing. Gene were considered significant with a fold change (FC) > 2 and false discovery rate of FDR < 0.05. Inhibitor experiments were conducted on CALU-3 cells using DIM-C-pPhOH 10 muM (NR4A1 antagonist), Sp600125 10 muM (JNK inhibitor), T-5224 10 muM (AP-1 transcription factor inhibitor) and Cytosporone B (CsB 5 muM;NR4A1 agonist) preincubated for 1 h with these compounds and subsequently infected with SARS-CoV-2 or MERS-CoV (MOI of 1). Samples were collect 24 h later for PCR. Result(s): PCR and RNA-Seq demonstrated that all tested coronaviruses efficiently infected ALI-PBEC and replicated over 72 h (p < 0.05). RNA sequencing analysis revealed that infection with SARS-CoV, MERS-CoV and HCoV-229E resulted in largely similar transcriptional responses by the epithelial cells. However, whereas infection with these viruses was accompanied by an increased expression of genes associated with JNK/AP-1 signalling, including FOS, FOSB and NR4A1 (FC > 1, FDR < 0.05), no such increase was observed following SARS-CoV-2 infection. Further, we found that an NR4A1 antagonist reduced viral replication of MERS and SARs-CoV-2 100-fold in Calu-3 cells. Conclusion(s): In conclusion, these data suggest that SARS-CoV-2-infected ALI-PBEC exhibit a unique transcriptional response compared to other coronaviruses, which might relate to the pathogenicity of the virus.

Application of the PHENotype SIMulator for rapid identification of potential candidates in effective COVID-19 drug repurposing.

The current, rapidly diversifying pandemic has accelerated the need for efficient and effective identification of potential drug candidates for COVID-19. Knowledge on host-immune response to SARS-CoV-2 infection, however, remains limited with few drugs approved to date. Viable strategies and tools are rapidly arising to address this, especially with repurposing of existing drugs offering significant promise. Here we introduce a systems biology tool, the PHENotype SIMulator, which -by leveraging available transcriptomic and proteomic databases-allows modeling of SARS-CoV-2 infection in host cells in silico to i) determine with high sensitivity and specificity (both>96%) the viral effects on cellular host-immune response, resulting in specific cellular SARS-CoV-2 signatures and ii) utilize these cell-specific signatures to identify promising repurposable therapeutics. Powered by this tool, coupled with domain expertise, we identify several potential COVID-19 drugs including methylprednisolone and metformin, and further discern key cellular SARS-CoV-2-affected pathways as potential druggable targets in COVID-19 pathogenesis.

Antiviral Activity of Interferon Alpha-2b and Taurine Combination Against SARS-CoV-2 in vitro

Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8°C, and after 1 month storage at the temperature of 20-26°C in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a «low» and 85% at a «high» multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.

Redirection of T cells via chimeric antigen receptor (CAR) to control the invasive fungal infections

Invasive fungal infections (IFI) are associated with high rates of morbidity and mortality, and immunocompromised hosts are often affected. Candida albicans is among the main cause of IFIs in the last decades, and Paracoccidioides brasiliensis is found in most of the IFIs identified in the South America. Rhizopus oryzae causes mucormycosis that increased in the COVID-19 pandemic. Host immune response against IFIs depend of the effector activity of T cells, which is compromised in immunodeficient patients. However, chimeric antigen receptor (CAR) technology can redirect T cells to target any antigen inducing the cell activation, which can be applied in immunocompromised patient as done in cell therapy against cancer. We developed a CAR (M-CAR) specific to a carbohydrate on the fungal cell wall, and Jurkat cells expressing M-CAR after lentiviral transduction using a multiplicity of infection (MOI) of 1, 3, 5 or 10 had its recognition capacity evaluated against C. albicans, P. brasiliensis, and R. oryzae. CAR expression increased in a MOI dependent-manner, and M-CAR Jurkat cells produced high levels of IL-2 in the presence of hyphae form of C. albicans,P. brasiliensis yeast, and R. oryzae spores. These findings evidenced the capacity of M-CAR to recognize these fungi inducing T cell activation. This work opened new perspectives to evaluate the fungicidal activity of human T and NK cells expressing M-CAR in response to species of fungi studied. Keywords: Chimeric Antigen Receptor (CAR), T cells, invasive fungal infections.

Process Development and Manufacturing: A SUPPLY CHAIN CRISIS STORY: CULTURE BAG SHORTAGE ENFORCED VALIDATION OF AN ALTERNATIVE EXPANSION SYSTEM FOR CAR T CELLS

Background & Aim: The recent supply chain crisis highlights a need to establish alternative manufacturing (MFG) protocols ensuring continuity of existing and new cell therapy (CT) clinical trials. Our academic CT program, and likely others, experienced purchasing delays and restrictions caused by diversion of critical supplies to meet COVID-19- related research demands and/or reduced vendor capacity due to resource constraints, including attrition of skilled workforce. Mitigation strategies aimed at creating process redundancies overcome production challenges resulting from a scarcity of goods. Here, we validated an alternative ex vivo culture system to clinically MFG lentiviral vector (LV) modified CAR T cells due to limited availability of cell expansion culture bags for the Wave bioreactor, a critical unit of operation that we have used to successfully MFG thousands of gene-modified T cell products for 30+ clinical trials. Methods, Results & Conclusion: The disposable G-REX culture vessels were compatible and seamlessly integrated with our closed system platform. Mesothelin CAR T cells were manufactured in parallel via the G-REX or conventional Wave bioreactor using consented patient starting material. Critical quality attributes of the final T cell products, including viability, transduction efficiency, phenotype and function were assessed. Transduction efficiencies assessed by flow cytometry and/or molecular qPCR were lower in products generated in the G-REX compared to the wave using the same multiplicity of infection. However, at least 50-fold expansion was achieved, with cell viabilities greater than 90% and with comparable cellular phenotypes. The Meso CAR T cells generated by either process were capable of eliciting CAR-mediated cytotoxicity and effector cytokine production. Strikingly, 2-4 billion T cells were harvested from a starting seed number of just 50 million T cells in the 1L G-REX, which may be sufficient to meet most protocol- specified cell therapy doses, suggesting that a full apheresis collection may not be needed. Notably, this process required just 1/3 of the starting material, 1/5 of the media and decreased manual effort through culture duration compared to the Wave. Additionally, the reduced reliance on specialized capital equipment combined with a small footprint enables simultaneous MFG of several immunotherapy products. These advantages propose consideration in replacement of current expansion platform as well as validating an alternative process for MFG CAR T cells.

EXPRESSION OF EPITHELIAL PROTEASES PREDICTS SARS-COV-2 ENTRY IN HUMAN ENTEROIDS

Introduction: Coronavirus Disease 2019 (COVID-19) is an ongoing public health crisis that has sickened or precipitated death in millions. The etiologic agent of COVID-19, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), infects the intestinal epithelium and can persist long after the respiratory infection has cleared. We previously observed that intestinal SARS-CoV-2 infection levels varied by individual donors and did not correlate positively with ACE2, the cognate SARS-CoV-2 receptor. Therefore we aimed to delineate host factors that influence viral infection in the intestine. Methods: Published dataset GSE75214 was downloaded and expression levels of select genes were querried. Primary human ileal spheroids (enteroids), derived from healthy donors and patients with Crohn's disease (CD), were grown on 2D transwells until confluent. Cells were differentiated for 3d before infection with a modified vesicular stomatitis virus expressing the SARS-CoV-2 spike protein (VSV-SARS-CoV-2) and GFP for 1h at a multiplicity of infection of ~0.5. Cells were harvested pre-infection and 24h after infection and expression of select genes was performed by qRT-PCR. Expression data were fit to a linear regression model to predict viral RNA levels. Results: Small intestine biopsy samples from CD patients demonstrated a reduction in ACE and an increase in CTSB and CTSL expression during active inflammation compared to healthy controls. Viral RNA expression did not correlate with ACE2 expression in CD enteroids. A subset of CD enteroids exhibited enhanced protease expression (TMPRSS2, TMPRSS4, CTSL), each of which correlated with higher viral RNA levels (P=0.04, P=0.002, P=0.006, respectively). Expression of these proteases was higher in the pre-infection for the sample subset. Principle component analysis of uninfected expression data demonstrated these samples clustered separately from the others, with the difference driven by TMPRSS2, TMPRSS4, and CTSL. Modeling viral RNA levels based on gene expression revealed expression levels of these proteases are a predictive expression signature. Conclusions: Host protease expression can predict SARS-CoV-2 infection and represent potential therapeutic targets for COVID-19. This is consistent with the recent report showing that cathepsin inhibition reduces SARS-CoV-2 spike-mediated syncytia formation. High expression of these proteases in the intestine may also be a novel biomarker for the risk of intestinal complications associated with COVID-19.(Figure Presented)RNA data from dataset GSE75214 demonstrating reduced ACE2 and increased CTSB and CTSL in patients with Crohn's disease during active inflammation compared to healthy controls. (Figure Presented) Enteroids from healthy control donors and patients with Crohn's disease were grown in 2D transwells and expression of indicated genes was assessed in pre-infection (A) and after infection with VSV-SARS-CoV-2 (B)

A Novel Host-Targeted Viral Assembly Inhibitor Blocks SARS-CoV-2 in Airway Epithelial Cells

Introduction: The rapid emergence of the SARS-CoV-2 Omicron variant that evades many monoclonal antibody therapies illustrates the need for anti-viral treatments with low susceptibility to evolutionary escape. The small molecule PAV-104, identified through a moderate-throughput screen involving cell-free protein synthesis, was recently shown to target a subset of host protein assembly machinery in a manner specific to viral assembly. This compound has minimal host toxicity, including once daily oral dosing in rats that achieves >200-fold of the 90% effective concentration (EC90) in blood. The chemotype shows broad activity against respiratory viral pathogens, including Orthomyxoviridae, Paramyxoviridae, Adenoviridae, Herpesviridae, and Picornaviridae, with low suceptability to evolutionary escape. We hypothesized that PAV-104 would be active against SARSCoV- 2 variants in human airway epithelial cells. Methods: Airway epithelial cells were differentiated from lung transplant tissue at air-liquid interface (ALI) for four weeks prior to challenge with Alpha (Pango lineage designation B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2) SARS-CoV-2 variants. Viral replication was determined by quantitative PCR measurement of the SARS-CoV-2 nucleocapsid (N) gene. Dose-dependent virus inhibition and cytotoxicity of PAV-104 in the Calu-3 airway epithelial cell line was determined by PCR and MTT assay. Student's t-tests were used to evaluate statistical significance. Results: Alpha, Beta, Gamma, and Delta variants of SARS-CoV-2 showed comparable infectivity in human primary airway epithelial cells at ALI (N=3 donors), 47- to 550-fold higher than the parent (USA-WA1/2020) strain. PAV-104 reached 50% cytotoxicity in Calu-3 cells at 240 nM (Fig. 1A). Dose-response studies in Calu-3 cells demonstrated PAV-104 has a 6 nM 50% inhibitory concentration (IC50) for blocking replication of SARS-CoV-2 (USA-WA1/2020) (Fig.1B). In primary cells at ALI from 3 donors tested, there was >99% inhibition of infection by SARS-CoV-2 Gamma variant (N=3, MOI 0.1, P <0.01) with 100 nM PAV-104 (Fig. 1C). Addition of 100 nM PAV-104 2-hours post-infection, but not pre-infection, resulted in >99% suppression of viral replication, indicating a post-entry drug mechanism. PAV-104 bound a small subset of the known allosteric modulator 14-3-3, itself implicated in the interactome of SARS-CoV-2. Conclusion: PAV-104 is a host-targeted, orally bioavailable, pan-viral small molecule inhibitor with promising activity against SARS-CoV-2 variants in human primary airway epithelial cells. (Figure Presented).

Induced Pluripotent Stem Cell Derived Airway to Assess Cystic Fibrosis Intrinsic Epithelial Response to SARS-CoV-2

Rationale There is a lack of knowledge of how CFTR-deficient airway epithelium intrinsically responds to SARS-CoV-2. Though prior work has demonstrated altered CF airway expression of viral entry factors, it is unknown whether these alterations are protective and whether they reflect host genetic variation or secondary response of chronic inflammation. We address this gap by infecting induced pluripotent stem cell (iPSC)-derived airways from CF patients and syngeneic CFTR-corrected controls with SARS-CoV-2 and assessing differential susceptibility to infection and inflammatory and anti-viral response. MethodsCF (F508del homozygous) and syngeneic CFTR-corrected (CRISPR-Cas9) iPSC- were differentiated into airway epithelium cultured at airliquid interface (ALI) by a directed differentiation protocol that generates a pure population of major and rare airway cell-types. After 21 days in ALI culture, the iPSC-airway were infected with either mock or SARS-CoV-2 (isolate USA-WA1/2020) with MOI of 4, and harvested at 0, 1, 3 days post infection (dpi) for RT-PCR and immune-stainingResultsBoth CF and CFTR-corrected iPSC-airway express viral entry factors of ACE2 and TMPRSS2, and are permissive to SARS-CoV-2 infection. CF iPSC-airway exhibited significantly increase in SARS-CoV-2 nucleocapsid protein (N) transcript at 1 dpi, accompanied by increases in IFN2, RSAD2, and CXCL10 at 3 dpi, compared to its CFTR-corrected counter-part. There are no baseline significant differences in ACE2, TMPRSS2, TP63, NGFR, MUC5B, MUC5AC, SCGB1A1, FOXJ1, FOXI1 expression between CF and CFTR-corrected iPSC-airway before SARS-CoV-2 infection. ConclusionsOur preliminary studies indicate increased early SARS-CoV-2 infection in CFTR-deficient epithelium with accompanied subsequent rise in anti-viral and inflammatory response compared to its genetically controlled CFTR-corrected counterpart. Future studies are aimed at assessing differential CF epithelial kinetics of SARS-CoV-2 viral entry and replication, morphological changes, global transcriptomic response, and how treatment with CFTRmodulator would alter the epithelial response. Ultimately, we aim to establish a reductionist, physiologically relevant model system that is coupled with gene-editing technology to study intrinsic CF epithelial response to SARS-CoV-2, which would generate insights to aid practice guidelines for CF patients, and open future directions to evaluate gene-specific mechanisms of airway response to pathogens. (Figure Presented).

THE EFFECTS of TYPE i & II IFNs DISCLOSE A ROLE for DOPAMINE in SARS-CoV-2 INFECTION

Background: Recent studies highlight the dynamic nature of virus-host interaction during SARS-CoV-2 infection, raising intriguing questions about the role and timing of interferon (IFN) responses. In fact, SARS-CoV-2 delays/antagonizes Type-I, and to a definitely lesser extent, Type II-IFNs. While paving the way for potential antiviral therapies based on immune activation, the molecular mechanisms linking different IFN pathways to SARS-CoV-2 susceptibility remain to be elucidated. The present study investigates the role of Type-I &-II IFNs in SARS-CoV-2 replication in human lung cells, with a focus on molecular pathways related with innate and adaptive immunity. Methods: Human lung carcinoma cells (CaLu3) were pretreated with IFN-α,-β or-γ (from 1 to 1000 U/mL), O.N. Cells were infected with SARS-CoV-2 (MOI 0.05) for 3h, and IFNs were added during infection. In another set of experiments, IFNs were added only p.i. Supernatants were harvested at 24 and 48h p.i. to assess viral replication by RT-qPCR, and to quantify the levels of cytokines/chemokines through Multiplex assay. At 48h post-infection, cells were collected and RNA was retrotranscribed to investigate a variety of transcriptional targets. Cell viability was assessed by MTT. Results are presented as the average of the relative expression units to the GAPDH gene, calculated by the 2-ΔΔCt equation. Statistical analyses were performed through the Student t-test. Results: Pretreatment with both Type-I &-II IFNs dramatically reduces SARS-CoV-2 replication in the absence of cell toxicity. Such an effect is maintained, though at a lower magnitude, when IFNs are added only p.i. The antireplicative effects of Type-I &-II IFNs are associated with both convergent and divergent mechanisms. Both Types decrease the expression and/or protein levels of most pro-inflammatory mediators while augmenting anti-inflammatory and anti-apoptotic factors. Surprisingly, IFN-γ shows the strongest effect in potentiating antiviral effectors besides boosting adaptive immunity pathways. Remarkably, a convergent effect of both IFN Types is observed upon the expression of genes associated with DA activity, including DA receptors (D1-D5) and the DA transporter (DAT), which are dramatically altered by SARS-CoV-2. Conclusion: Both Type-I &-II IFNs halt SARS-CoV-2 replication by acting through complementary mechanisms. Their effects also disclose a potential role for DA activity, and neuromodulators in general, in host immunity during SARS-CoV-2 infection in pulmonary cells.

Containing the spread of COVID-19 virus facing to its high mutation rate: approach to intervention using a nonspecific way of blocking its entry into the cells.

Viruses have multiple mutation rates that are higher than any other member of the kingdom of life. This gives them the ability to evolve, even within the course of a single infection, and to evade multiple host defenses, thereby impacting pathogenesis. Additionally, there are also interplays between mutation and recombination and the high multiplicity of infection (MOI) that enhance viral adaptability and increase levels of recombination leading to complex and conflicting effects on genome selection, and the net results is difficult to predict. Recently, the outbreak of COVID-19 virus represents a pandemic threat that has been declared a public health emergency of international concern. Up to present, however, due to the high mutation rate of COVID-19 virus, there are no effective procedures to contain the spread of this virus across the globe. For such a purpose, there is then an urgent need to explore new approaches. As an opinion, the present approach emphasizes on (a) the use of a nonspecific way of blocking the entry of COVID-19 virus as well as its variants into the cells via a therapeutic biocompatible compound (ideally, "in a pill") targeting its spike (S) glycoprotein; and (b) the construction of expression vectors via the glycosyl-phosphatidylinositol, GPI, anchor for studying intermolecular interactions between the spike S of COVID-19 virus as well as its variants and the angiotensin-converting enzyme 2 (ACE2) of its host receptor for checking the efficacy of any therapeutic biocompatible compound of the nonspecific way of blocking. Such antiviral drug would be safer than the ACE1 and ACE2 inhibitors/angiotensin receptor blockers, and recombinant human ACE2 as well as nucleoside analogs or protease inhibitors used for fighting the spread of the virus inside the cells, and it would also be used as a universal one for any eventual future pandemic related to viruses, especially the RNA viruses with high mutation rates.

Targeting vimentin impacts multiple cellular processes, blocks the spike protein-ACE2-mediated pseudoviral infection in vitro and reduces the symptom and lung injury in aged mice with mouse-adapted SARS-CoV-2 infection in vivo

Vimentin intermediate filament is involved in multiple steps of viral infection such as viral entry, trafficking and egress, as well as in various mechanisms of hyperinflammation such as the restraint of Treg cell functions and the activation of NLRP3 inflammasome. We evaluated a vimentin-binding small molecule compound ALD-R491 for its effects on cellular processes related to viral infection and for its efficacy in treating SARS-CoV2 infection in vitro and in vivo. In cultured cells, the compound could reduce endocytosis by 10%, endosomal trafficking by 40% and exosomal release by over 30%. In an infection system consisting of a lentiviral pseudotype bearing the SARS-CoV-2 spike protein and HEK293 cells over-expressing the human ACE2 receptor with multiplicity of infection (MOI) of 1, 10 and 100, the compound inhibited the infection up to a maximum of over 90%, with IC 50 < 50 nM, CC50 > 10 μM, and SI > 200. After oral administration of ALD-R491 in rats, the plasma concentration of the compound reached the peak (Tmax) at around 5 h with a half-life (T1/2) of about 5 h. The compound was widely distributed and enriched in tissues in vivo in rats with a volume of distribution (Vd) of over 2,000 ml/kg. The lung and the lymph nodes were among the tissues with high drug exposures. In rats receiving oral gavage of the compound at 30 mg/kg, the drug exposure in the lung and the lymph nodes maintained at levels over 1 μM from 1 h to 6 h after the oral dosing. In the syngeneic mouse tumor CT26 model, ALD-R491 was found to activate regulatory T cells (Tregs) in vivo and enhance de novo generation of Tregs in lymph nodes of the mice. In the Mouse-Adapted SARS-CoV2 model, aged mice (11-12 months) were used to provide a harder test of recovery from infection that reflects the severeness of COVID-19 in old patients. For therapeutic treatment, the mice were orally administered with the compound 24 h after the SARS-CoV2 infection once per day on Day 1, Day 2 and Day 4. At 10 mg/kg, ALD-R491 significantly reduced the body weight loss of the mice (p<0.01 on Day 5 post-infection). At both 3 mg/kg and 10 mg/kg, the compound significantly reduced the hemorrhagic score for the lungs (p<0.01 and p<0.05, respectively, on Day 5). These results indicate that vimentin intermediate filament is an effective host-directed antiviral target. Importantly, the vimentin-binding small molecule ALD-R491 impacts multiple aspects of SARS-CoV2 infection, has a favorable oral pharmacokinetics and a wide therapeutic window, and therefore may be a promising therapeutic candidate for treating COVID-19. Statement: Aluda Pharmaceuticals, Inc. has utilized the non-clinical and pre-clinical services program offered by the National Institute of Allergy and Infectious Diseases.

Iota-carrageenan extracted from red algae is a potent inhibitor of SARS-CoV-2 infection in reconstituted human airway epithelia.

Iota-carrageenan (IC) nasal spray, a medical device approved for treating respiratory viral infections, has previously been shown to inhibit the ability of a variety of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to enter and replicate in the cell by interfering with the virus binding to the cell surface. The aim of this study was to further investigate the efficacy and safety of IC in SARS-CoV-2 infection in advanced in vitro models of the human respiratory epithelium, the primary target and entry port for SARS-CoV-2. We extended the in vitro safety assessment of nebulized IC in a 3-dimensional model of reconstituted human bronchial epithelium, and we demonstrated the efficacy of IC in protecting reconstituted nasal epithelium against viral infection and replication of a patient-derived SARS-CoV-2 strain. The results obtained from these two advanced models of human respiratory tract epithelia confirm previous findings from in vitro SARS-CoV-2 infection assays and demonstrate that topically applied IC can effectively prevent SARS-CoV-2 infection and replication. Moreover, the absence of toxicity and functional and structural impairment of the mucociliary epithelium demonstrates that the nebulized IC is well tolerated.

Insights into forsythia honeysuckle (Lianhuaqingwen) capsules: A Chinese herbal medicine repurposed for COVID-19 pandemic.

Background: In December 2019, a novel coronavirus, SARS-CoV-2 caused a series of acute atypical respiratory diseases worldwide. However, there is still a lack of drugs with clear curative effects, and the clinical trial research of vaccines has not been completely finished. Purpose: LH capsules are approved TCM patent medicine that are widely used for the treatment of respiratory tract infectious diseases caused by colds and flu. On April 12, 2020, LH capsules and granules were officially repurposed by the China Food and Drug Administration (CFDA) for patients with mild COVID-19 based on their safety and efficacy demonstrated through multicentre, randomized, controlled clinical trials. We hope to conduct a comprehensive review of it through modern pharmacy methods, and try to explain its possible mechanism. Methods: Using the full names of LH capsules Lianhuaqingwen, Lianhua Qingwen andSARS-COV-2, COVID-19 as the keywords of the search terms, systemically search for existing related papers in various databases such as Web of Science and PubMed. And completed the collection of clinical data in ClinicalTrials.gov and Chinese Clinical Trial Registry. Last but not least, we have sorted out the anti-inflammatory and antiviral mechanisms of LH capsules through literature and Selleck. Results: This review systematically sorted out the active ingredients in LH capsules. Furthermore, the related pharmacological and clinical trials of LH capsule on SARS-CoV-2, IAV and IBV were discussed in detail. Moreover, the present review provides the first summary of the potential molecular mechanism of specific substances in LH capsules involved in resistance to SARS-COV-2 infection and the inhibition of cytokine storm syndrome (CSS) caused by IL-6. Conclusion: This review summarizes the available reports and evidence that support the use of LH capsules as potential drug candidates for the prevention and treatment of COVID-19. However, TCM exerts its effects through multiple targets and multiple pathways, and LH capsules are not an exception. Therefore, the relevant mechanisms need to be further improved and experimentally verified.