Porcine reproductive and respiratory syndrome virus(PRRSV) shows characteristic antibody-dependent enhancement(ADE) of infection and causes porcine systemic inflammation, which is similar to a type I allergic reaction...Porcine reproductive and respiratory syndrome virus(PRRSV) shows characteristic antibody-dependent enhancement(ADE) of infection and causes porcine systemic inflammation, which is similar to a type I allergic reaction; however, the role of porcine FceεRI in ADE is still unclear. In this study, the expression of different Fc receptors(Fc Rs) on macrophages was investigated in a PRRSV 3D4/21 cell infection model in the presence or absence of PRRSV antibody. The transcription level of Fcc II and FceεRI was significantly up-regulated under PRRSV-antibody complex infection. Internalization and proliferation of PRRSV were promoted by the ADE mechanism when FceεRI was expressed in permissive 3D4/21 cells and the non-permissive cell line HEK 293T. Transcriptome sequencing data showed that the expression levels of AKT,ERK and other signal molecules in the anti-inflammatory pathway were significantly increased, especially in the cells infected with the PRRSV-antibody immune complex. Inflammatory regulatory molecules such as PLA2G6, LOX, TRPM8 and TRPM4 were significantly up-regulated following PRRSV infection but significantly down-regulated in the cells infected with the PRRSV-antibody immune complex. Our results demonstrated that FceεRI could be involved in PRRSV ADE, the antigen presenting process and regulation of the inflammatory response during PRRSV infection, which provides new insights into PRRSV infection mediated by FceεRI and the PRRSV-antibody immune complex.展开更多
Mast cells(MCs),hematopoietic cells of the myeloid lineage,are well-known for their pro-inflammatory nature contributing to the development of various allergic and autoimmune diseases.One of the characteristic recepto...Mast cells(MCs),hematopoietic cells of the myeloid lineage,are well-known for their pro-inflammatory nature contributing to the development of various allergic and autoimmune diseases.One of the characteristic receptors on MCs,the high-affinity receptor for IgE(FcεRI),is activated in its IgE-bound state via binding and crosslinking by polyvalent antigen.This results in its phosphorylation by the SRC family kinase LYN,initiating differential signaling pathways,eventually triggering immunological effector functions,such as degranulation and cytokine production.Few publications have reported on FcεRI-dependent but antigen-independent MC activation by antibody-mediated crosslinking of membrane molecules(e.g.,transmembrane proteins and glycosphingolipids)that are both localized in membrane rafts and in close vicinity to the FcεRI.In this Viewpoint we will briefly introduce FcεRI-mediated MC stimulation,cite examples of FcεRI-proximal molecules,the crosslinking of which can cause FcεRI-dependent MC activation,and discuss the potential of certain viruses as well as auto-antibodies to act as indirect FcεRI-crosslinking agents.In latter cases,antigen-independent FcεRI-mediated pro-inflammatory MC activation could contribute to the development of detrimental cytokine storms.展开更多
The primers were designed according to the gene sequence of lipocalin protein family,and the gene sequence containing random mutation protein was obtained by overlapping extension of PCR.The random mutation lipocalin ...The primers were designed according to the gene sequence of lipocalin protein family,and the gene sequence containing random mutation protein was obtained by overlapping extension of PCR.The random mutation lipocalin library was constructed using phagemid expression vector.Lipocalin library was screened by subtracted screening of NSF60 cells and affinity screening of mast cells,and the lipocalin secondary library binding to mast cells was obtained.Then the lipocalin secondary library was enriched and screened with FcεRI-αreceptor protein as target molecule,and specific binding phages were eluted.After three rounds of screening,eight recombinant phage clones were randomly selected from elution clones of the third round.ELISA assay showed that three anticalin molecules could specifically bind to the FcεRI-αreceptor of mast cells.These results may provide some candidate biological molecules for the development of blocking drugs of mast cell FcεRI-αreceptor,and also lay the foundation for the development of biological small molecule drugs to treat Ig E associated allergic diseases.展开更多
基金supported by the National Natural Science Foundation of China (31272540)the underprop project of Tianjin Science and Technology Committee in China (16YFZCNC00640)
摘要Porcine reproductive and respiratory syndrome virus(PRRSV) shows characteristic antibody-dependent enhancement(ADE) of infection and causes porcine systemic inflammation, which is similar to a type I allergic reaction; however, the role of porcine FceεRI in ADE is still unclear. In this study, the expression of different Fc receptors(Fc Rs) on macrophages was investigated in a PRRSV 3D4/21 cell infection model in the presence or absence of PRRSV antibody. The transcription level of Fcc II and FceεRI was significantly up-regulated under PRRSV-antibody complex infection. Internalization and proliferation of PRRSV were promoted by the ADE mechanism when FceεRI was expressed in permissive 3D4/21 cells and the non-permissive cell line HEK 293T. Transcriptome sequencing data showed that the expression levels of AKT,ERK and other signal molecules in the anti-inflammatory pathway were significantly increased, especially in the cells infected with the PRRSV-antibody immune complex. Inflammatory regulatory molecules such as PLA2G6, LOX, TRPM8 and TRPM4 were significantly up-regulated following PRRSV infection but significantly down-regulated in the cells infected with the PRRSV-antibody immune complex. Our results demonstrated that FceεRI could be involved in PRRSV ADE, the antigen presenting process and regulation of the inflammatory response during PRRSV infection, which provides new insights into PRRSV infection mediated by FceεRI and the PRRSV-antibody immune complex.
基金MH was supported by the Deutsche Forschungsgemeinschaft(DFG HU794/12-1).
摘要Mast cells(MCs),hematopoietic cells of the myeloid lineage,are well-known for their pro-inflammatory nature contributing to the development of various allergic and autoimmune diseases.One of the characteristic receptors on MCs,the high-affinity receptor for IgE(FcεRI),is activated in its IgE-bound state via binding and crosslinking by polyvalent antigen.This results in its phosphorylation by the SRC family kinase LYN,initiating differential signaling pathways,eventually triggering immunological effector functions,such as degranulation and cytokine production.Few publications have reported on FcεRI-dependent but antigen-independent MC activation by antibody-mediated crosslinking of membrane molecules(e.g.,transmembrane proteins and glycosphingolipids)that are both localized in membrane rafts and in close vicinity to the FcεRI.In this Viewpoint we will briefly introduce FcεRI-mediated MC stimulation,cite examples of FcεRI-proximal molecules,the crosslinking of which can cause FcεRI-dependent MC activation,and discuss the potential of certain viruses as well as auto-antibodies to act as indirect FcεRI-crosslinking agents.In latter cases,antigen-independent FcεRI-mediated pro-inflammatory MC activation could contribute to the development of detrimental cytokine storms.
基金The Science and Technology Project Foundation of Guangzhou,China(Grant No.201604020106)Natural Science Foundation of Guangdong Province(Grant No.1814050002837)
摘要The primers were designed according to the gene sequence of lipocalin protein family,and the gene sequence containing random mutation protein was obtained by overlapping extension of PCR.The random mutation lipocalin library was constructed using phagemid expression vector.Lipocalin library was screened by subtracted screening of NSF60 cells and affinity screening of mast cells,and the lipocalin secondary library binding to mast cells was obtained.Then the lipocalin secondary library was enriched and screened with FcεRI-αreceptor protein as target molecule,and specific binding phages were eluted.After three rounds of screening,eight recombinant phage clones were randomly selected from elution clones of the third round.ELISA assay showed that three anticalin molecules could specifically bind to the FcεRI-αreceptor of mast cells.These results may provide some candidate biological molecules for the development of blocking drugs of mast cell FcεRI-αreceptor,and also lay the foundation for the development of biological small molecule drugs to treat Ig E associated allergic diseases.