[Up-regulated expression of FcγRIIB inhibits phagocytosis and chemotaxis of macrophages].
OBJECTIVE
To construct an inducible lentivirus vector of FcγRIIB and observe its effect on rat macrophages.


METHODS
FcγRIIB gene fragment was obtained from rat liver mRNA as the template by reverse transcription PCR, and then cloned into tetracycline response element (TRE) plasmid to establish recombinant plasmid TRE-FcγRIIB. Lentiviral packaging plasmid was transfected into HEK293T cells together with the recombinant plasmid TRE-FcγRIIB and Tet plasmid, respectively. Then the titers of the above lentiviruses were measured. Rat macrophages were co-infected by FcγRIIB-lentivirus and Tet-lentivirus, thereafter induced by doxycycline (DOX) of gradient concentrations. The mRNA and protein levels of FcγRIIB were measured by immunofluorescence, real-time quantitative PCR (qRT-PCR) and Western blotting. After induced by DOX, macrophages were detected in phagocytic and chemotactic function.


RESULTS
The recombinant plasmid we constructed was confirmed correct by PCR, enzyme digestion and sequencing. The titers of FcγRIIB-lentivirus and Tet-lentivirus reached 10(6) TU/mL. FcγRIIB was expressed under DOX induction in macrophages which were co-infected by the packaged lentiviruses. In addition, FcγRIIB level was positively correlated with the concentration of DOX, but was negatively correlated with phagocytosis and chemotaxis of macrophages.


CONCLUSIONS
The up-regulation of FcγRIIB expression in macrophages might suppress cell phagocytosis and chemotaxis.
Department of Pathogenic Biology and Immunology, School of Basic Medicine, Ningxia Medical University, Yinchuan 750004, China.
Xiujun
X
Zheng
Department of Pathogenic Biology and Immunology, School of Basic Medicine, Ningxia Medical University, Yinchuan 750004, China.
Qi
Q
Wang
Ministry of Education and Ningxia Provincial Key Laboratory of Fertility Preservation and Maintenance, Yinchuan 750004, China.
Xiuqin
X
Cao
Department of Pathogenic Biology and Immunology, School of Basic Medicine, Ningxia Medical University, Yinchuan 750004, China.
Zhiwei
Z
Yang
D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002633:Chemotaxis / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000276:immunology / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D051381:Rats; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology*
C499171:Fcgr2b protein, rat; D017452:Receptors, IgG; D004318:Doxycycline