1.Expression and purification of r ecombinant circumsporozoite proteins of Plasmodium falciparum and evaluation of their binding activities to hepatocytes
Lili QU ; Yanyun WANG ; Lailing GONG ; Peng SHEN ; Jin ZHU ; Jin SI
Chinese Journal of Microbiology and Immunology 2014;(5):349-353
Objective To amplify four fragments of circumsporozoite ( CSP) protein gene from Plasmodium falciparum FCC1/HN strain and express recombinant CSP proteins in prokaryotic vector pET28 a/EGFP for further evaluation of their binding activities to hepatic cells .Methods Four pairs of primers were designed according to the cDNA sequence of CSP protein from Plasmodium falciparum FCC1/HN strain and used to amplify the gene fragments by PCR .The cloned gene fragments were inserted into pET28a/EGFP to construct the recombinant expression plasmids .The transformed E.coli BL21 strains carry-ing expression plasmids were induced by IPTG to express CPS proteins .The recombinant CSP proteins were purified with Ni2+chelating HiTrap HP column and detected by SDS-PAGE.The binding activities of the ex-pressed proteins to different tissues were also detected .Results Four gene fragments encoding CSP protein were successfully amplified and expressed in E.coil BL21 strain as fusion protein CSR1a-EGFP, CSR1b-EGFP, CSR2a-EGFP and CSR2b-EGFP with a relative molecular mass of about 39×103, 31×103, 33×103 and 30 ×10 3 , respectively .The purified fusion proteins reacted specifically with Plasmodium falciparum-posi-tive serum samples.Moreover, the recombinant protein CSR2a-EGFP could bind to the hepatic cells specif-ically rather than other cells.Conclusion The purified recombinant CSR2a-EGFP protein has a strong binding activity to hepatocytes , indicating its potential value as a targeting molecule for hepatic gene therapy .
2.Predictive values of serum PCT,IL-6,HBP and CRP levels in cerebral infarction complicated with pulmonary infection
Tian TIAN ; Hongxiang LV ; Fan YANG ; Min RONG ; Lailing GONG
Chinese Journal of Clinical Laboratory Science 2024;42(5):343-347
Objective To investigate the predictive value of procalcitonin(PCT),interleukin-6(IL-6),heparin binding protein(HBP),and C-reactive protein(CRP)in cerebral infarction(CI)complicated with pulmonary infection.Methods 145 CI patients treated in Jiangning Hospital Affiliated to Nanjing Medical University from July 2022 to June 2023 were selected as the CI group.Ac-cording to whether combined with pulmonary infection,they were divided into the co-infected group(n=76)with pulmonary infection and the simple CI group(n=69)without pulmonary infection.61 healthy volunteers performed physical examination in our hospital at the same time were enrolled as the control group.The general clinical data from each group were collected and their serum biochemical indicators were compared.The multivariate Logistic regression was used to analyze the risk factors of CI complicated with pulmonary in-fection and the receiver operating characteristic(ROC)curve was constructed.The area under the ROC curve(AUCROC)was used to evaluate the diagnostic value of each index for CI complicated with pulmonary infection.Results Age,PCT,IL-6,HBP,and CRP were the independent risk factors of CI complicated with pulmonary infection(P<0.05).The ROC curve analysis showed that each in-dex of PCT,IL-6,HBP,and CRP had a certain value in predicting CI combined with pulmonary infection.The sensitivity and specific-ity of the combination detection of PCT,IL-6,HBP,and CRP were 85.47%and 75.36%,respectively,which were significantly high-er than that of the single detection of PCT,IL-6,HBP,and CRP(P<0.05).Conclusion The levels of serum PCT,IL-6,HBP,and CRP are highly expressed in CI patients combined with pulmonary infection.They can be used for the diagnosis of CI combined with pulmonary infection.The combination detection of the four indexes can effectively improve the diagnosis accuracy of CI complicated with pulmonary infection.