SETDB1-mediated CD147-K71 di-methylation promotes cell apoptosis in non-small cell lung cancer

Protein post-translational modifications(PTMs)are at the heart status of cellular signaling events and broadly involved in tumor progression.CD147 is a tumor biomarker with various PTMs,promoting tumor metastasis and metabolism reprogramming.Nevertheless,the relationship between the PTMs of CD147 and apoptosis has not been reported.In our study,we produced a specific anti-CD147-K71 di-methylation(CD147-K71me2)antibody by immunizing with a di-methylated peptide and observed that the level of CD147-K71me2 in non-small cell lung cancer(NSCLC)tissues were lower than that in NSCLC adjacent tissues.SETDB1 was identified as the methyltransferase catalyzing CD147 to generate CD147-K71me2.RNA-seq showed that FOSB was the most significant differentially expressed gene(DEG)between wild-type CD147(CD147-WT)and K71-mutant CD147(CD147-K71R)groups.Subsequently,we found that CD147-K71me2 promoted the expression of FOSB by enhancing the phosphorylation of p38,leading to tumor cell apoptosis.In vivo experiments showed that CD147-K71me2 significantly inhibited tumor progression by promoting cell apoptosis.Taken together,our findings indicate the inhibitory role of CD147-K71me2 in tumor progression from the perspective of post-translational modification,which is distinct from the pro-cancer function of CD147 itself,broadening our perspective on tumor-associated antigen CD147.

Meplazumab in hospitalized adults with severe COVID-19(DEFLECT):a multicenter,seamless phase 2/3,randomized,third-party double-blind clinical trial

Meplazumab,a humanized CD147 antibody,has shown favourable safety and efficacy in our previous clinical studies.In DEFLECT(NCT04586153),167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo.Meplazumab at 0.12 mg/kg,compared to the placebo group,showed clinical benefits in significantly reducing mortality by 83.6%(2.4%vs.14.6%,p=0.0150),increasing the proportion of patients alive and discharged without supplemental oxygen(82.9%vs.70.7%,p=0.0337)and increasing the proportion of patients who achieved sustained clinical improvement(41.5%vs.31.7%).The response rate in the 0.2 mg/kg group was relatively increased by 16.0%compared with the placebo group(53.7%vs.46.3%).Meplazumab also reduced the viral loads and multiple cytokine levels.Compare with the placebo group,the 0.3 mg/kg significantly increased the virus negative rate by 40.6%(p=0.0363)and reduced IL-8 level(p=0.0460);the 0.2 mg/kg increased the negative conversion rate by 36.9%,and reduced IL-4(p=0.0365)and IL-8 levels(p=0.0484).In this study,the adverse events occurred at a comparable rate across the four groups,with no unexpected safety findings observed.In conclusion,meplazumab promoted COVID-19 convalescence and reduced mortality,viral load,and cytokine levels in severe COVID-19 population with good safety profile.

Immunological and metabolic characteristics of the Omicron variants infection

The Omicron variants of SARS-CoV-2,primarily authenticated in November 2021 in South Africa,has initiated the 5th wave of global pandemics.Here,we systemically examined immunological and metabolic characteristics of Omicron variants infection.We found Omicron resisted to neutralizing antibody targeting receptor binding domain(RBD)of wildtype SARS-CoV-2.Omicron could hardly be neutralized by sera of Corona Virus Disease 2019(COVID-19)convalescents infected with the Delta variant.Through mass spectrometry on MHC-bound peptidomes,we found that the spike protein of the Omicron variants could generate additional CD8+T cell epitopes,compared with Delta.These epitopes could induce robust CD8+T cell responses.Moreover,we found booster vaccination increased the cross-memory CD8+T cell responses against Omicron.Metabolic regulome analysis of Omicron-specific T cell showed a metabolic profile that promoted the response of memory T cells.Consistently,a greater fraction of memory CD8+T cells existed in Omicron stimulated peripheral blood mononuclear cells(PBMCs).In addition,CD147 was also a receptor for the Omicron variants,and CD147 antibody inhibited infection of Omicron.CD147-mediated Omicron infection in a human CD147 transgenic mouse model induced exudative alveolar pneumonia.Taken together,our data suggested that vaccination booster and receptor blocking antibody are two effective strategies against Omicron.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.

CD147 antibody specifically and effectively inhibits infection and cytokine storm of SARS-CoV-2 and its variants delta,alpha,beta,and gamma

SARS-CoV-2 mutations contribute to increased viral transmissibility and immune escape,compromising the effectiveness of existing vaccines and neutralizing antibodies.An in-depth investigation on COVID-19 pathogenesis is urgently needed to develop a strategy against SARS-CoV-2 variants.Here,we identified CD147 as a universal receptor for SARS-CoV-2 and its variants.Meanwhile,Meplazeumab,a humanized anti-CD147 antibody,could block cellular entry of SARS-CoV-2 and its variants-alpha,beta,gamma,and delta,with inhibition rates of 68.7,75.7,52.1,52.1,and 62.3%at 60μg/ml,respectively.Furthermore,humanized CD147 transgenic mice were susceptible to SARS-CoV-2 and its two variants,alpha and beta.When infected,these mice developed exudative alveolar pneumonia,featured by immune responses involving alveoli-infiltrated macrophages,neutrophils,and lymphocytes and activation of IL-17 signaling pathway.Mechanistically,we proposed that severe COVID-19-related cytokine storm is induced by a"spike protein-CD147-CyPA signaling axis":Infection of SARS-CoV-2 through CD147 initiated the JAK-STAT pathway,which further induced expression of cyclophilin A(CyPA);CyPA reciprocally bound to CD147 and triggered MAPK pathway.Consequently,the MAPK pathway regulated the expression of cytokines and chemokines,which promoted the development of cytokine storm.Importantly,Meplazumab could effectively inhibit viral entry and inflammation caused by SARS-CoV-2 and its variants.Therefore,our findings provided a new perspective for severe COVID-19-related pathogenesis.Furthermore,the validated universal receptor for SARS-CoV-2 and its variants can be targeted for COVID-19 treatment.

Safety and efficacy of meplazumab in healthy volunteers and COVID-19 patients: a randomized phase 1 and an exploratory phase 2 trial

Recent evidence suggests that CD147 serves as a novel receptor for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.Blocking CD147 via anti-CD147 antibody could suppress the in vitro SARS-CoV-2 replication.Meplazumab is a humanized anti-CD147 IgG_(2) monoclonal antibody,which may effectively prevent SARS-CoV-2 infection in coronavirus disease 2019(COVID-19)patients.Here,we conducted a randomized,double-blinded,placebo-controlled phase 1 trial to evaluate the safety,tolerability,and pharmacokinetics of meplazumab in healthy subjects,and an open-labeled,concurrent controlled add-on exploratory phase 2 study to determine the efficacy in COVID-19 patients.In phase 1 study,59 subjects were enrolled and assigned to eight cohorts,and no serious treatment-emergent adverse event(TEAE)or TEAE grade≥3 was observed.The serum and peripheral blood Cmax and area under the curve showed non-linear pharmacokinetic characteristics.No obvious relation between the incidence or titer of positive anti-drug antibody and dosage was observed in each cohort.The biodistribution study indicated that meplazumab reached lung tissue and maintained>14 days stable with the lung tissue/cardiac blood-pool ratio ranging from 0.41 to 0.32.In the exploratory phase 2 study,17 COVID-19 patients were enrolled,and 11 hospitalized patients were involved as concurrent control.The meplazumab treatment significantly improved the discharged(P=0.005)and case severity(P=0.021),and reduced the time to virus negative(P=0.045)in comparison to the control group.These results show a sound safety and tolerance of meplazumab in healthy volunteers and suggest that meplazumab could accelerate the recovery of patients from COVID-19 pneumonia with a favorable safety profile.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.

CD98-induced CD147 signaling stabilizes the Foxp3 protein to maintain tissue homeostasis

Regulatory T cell(Treg)stability is necessary for the proper control of immune activity and tissue homeostasis.However,it remains unclear whether Treg stability must be continually reinforced or is established during development under physiological conditions.Foxp3 has been characterized as a central mediator of the genetic program that governs Treg stability.Here,we demonstrate that to maintain Foxp3 protein expression,Tregs require cell-to-cell contact,which is mediated by the CD147-CD98 interaction.As Tregs are produced,CD147,which is expressed on their surface,is stimulated by CD98,which is widely expressed in the physiological environment.As a result,CD147’s intracellular domain binds to CDK2 and retains it near the membrane,leading to Foxp3 dephosphorylation and the prevention of Foxp3 degradation.In addition,the optimal distribution of Foxp3+Tregs under both pathological and physiological conditions depends on CD98 expression.Thus,our study provides direct evidence that Foxp3-dependent Treg stability is reinforced in the periphery by the interaction between CD147 and CD98 in the surrounding environment.More importantly,Tregs with high CD147 expression effectively inhibit inflammatory responses and maintain Foxp3 stability,which has guiding significance for the application of Tregs in immunotherapy.

CD147 deficiency in T cells prevents thymic involution by inhibiting the EMT process in TECs in the presence of TGFβ

Thymic involution during aging is a major cause of decreased T-cell production and reduced immunity.Here,we show that the loss of CD147 on T cells prevents thymic senescence,resulting in slowed shrinkage of the thymus with age and increased production of naive T cells.This phenotype is the result of slowing of the epithelial-mesenchymal transition(EMT)process in thymic epithelial cells(TECs),which eventually leads to reduced adipocyte accumulation.In an in vitro coculture system,we found that TGFβ is an important factor in the EMT process in TECs and that it can reduce the expression of E-cadherin through p-5mad2/FoxC2 signaling.Moreover,CD147 on T cells can accelerate the decline in E-cadherin expression by interacting with Annexin A2 on TECs.In the presence of TGFβ,Annexin A2 and E-cadherin colocalize on TECs.However,CD147 on T cells competitively binds to Annexin A2 on TECs,leading to the isolation of E-cadherin.Then,the isolated E-cadherin is easily phosphorylated by phosphorylated Src kinase,the phosphorylation of which was induced by TGFβ,and finally,p-E-cadherin is degraded.Thus,in the thymus,the interaction between T ceils and TECs contributes to thymic involution with age.In this study,we illuminate the mechanism underlying the triggering of the EMT process in TECs and show that inhibiting TGFβ and/or CD147 may serve as a strategy to hinder age-related thymic involution.