Preparation of mouse monoclonal antibodies against human adenovirus 55 Hexon (HAdV55 Hexon) protein / 细胞与分子免疫学杂志

Objective To prepare specific mouse monoclonal antibody (mAb) against human adenovirus type 55 Hexon protein (HAdV55 Hexon). Methods The Hexon genes of HAdV55, 3, 4, 7, 16 and 21 were chemically synthesized as templates for PCR amplification. The prokaryotic expression plasmids pET28a-HAdV55 Hexon and eukaryotic expression plasmids pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon were constructed respectively. The pET28a-HAdV55 Hexon plasmid was transformed into E. coli competent cell BL21 (DE3) and was induced by IPTG. After the purified inclusion body was denatured and renatured, Hexon55 protein was purified by tangential flow filtration system. pCAGGS-HAdV55 Hexon was used to immunize BALB/c mice by cupping, and HAdV55 Hexon protein was used to booster immunization. The anti-HAdV55 Hexon mAb was prepared by hybridoma technique and the titer and subclass were determined. The specificity of antibody was identified by Western blot using HEK293T cells transfected with pCAGGS-HAdV55 Hexon and by immunofluorescence assay (IFA) using BHK cells transfected with pCAGGS-HAdV55 Hexon. Both clones with high titer were selected, and the cross-reactivity of pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon transfected cells were analyzed by Western blot analysis and IFA. Results PET28a-HAdV55 Hexon and pCAGGS-HAdV55 Hexon, 3, 4, 7, 16 and 21 expression plasmids were successfully constructed. BL21 transformed with pET28a-HAdV55 Hexon was induced by IPTG. The HAdV55 Hexon protein was mainly expressed in the form of inclusion body. After denaturation and renaturation, the purified HAdV55 Hexon protein was obtained by ultrafiltration. Six hybridoma cell lines secreting HAdV55 Hexon mAb were obtained. The antibody subclass analysis showed that 2 strains were IgG2a subtypes and 4 strains were IgG2b. Two specific HAdV55 Hexon antibodies with high titer were obtained, and there was no cross-reactivity with HAdV3, 4, 7, 16, 21 Hexon. Conclusion The specific mice mAb against HAdV55 Hexon provides an experimental basis for establishing its antigen detection method.

Evaluation of neutralizing antibodies in serum immunized with virus-like particle chimerized HCV series of neutralizing epitopes / 中国免疫学杂志

Objective:New Zealand rabbits were immunized with VLPs-MEpS,VLPs-E2S,and the levels of neutralizing antibodies in serum were determined.Methods: New Zealand rabbits were immunized with 10 μg VLPs-MEpS and VLPs-E2S,serum was collected at diffferent time with a two-weeks interval.The neutralizing antibodies were determined by ELISA.HCV(type 1b) had been prepared and mixed with serum from immunized rabbit before infected Huh7.5 cell.The protection of neutralizing antibodies in serum was assessed.Results: Neutralizing antibodies had been induced in rabbit after immunized with VLPs-MEpS and VLPs-E2S.VLPs-MEpS group had higher titer of antibodies than that of VLPs-E2S group(P<0.05),both group had higher titer of antibodies than that of control groups significantly(P<0.01).VLPs-MEpS group had higher neutralization than that of VLPs-E2S group(P<0.05),the highest neutralization rate was 61.49%.Both groups were higher than control group notably(P<0.01).Conclusion: Protective neutralizing antibodies have been induced in New Zealand rabbit after immunized with VLPs-MEpS and VLPs-E2S.It′s the basement for development of neutralizing antibodies vaccine.

Cloning and characterization of the heavy chain variable region gene of monoclonal antibody 2F2 against Japanese encephalitis virus / 中国医师杂志

Objective To obtain the heavy chain variable region (VH) gene of monoclonal antibody 2F2 against Japanese encephalitis virus (JEV).Methods Total RNA was isolated with Trizol from hybridoma 2F2 cells,and cDNA of VH was amplified with reverse transcription polymerase chain reaction (RT-PCR) and sequenced.The putative VH gene was expressed in E.coli,and the expressed products was detected with enzyme linked immunosorbent assay (ELISA) to determine the activity to bind JEV.Results The VH gene was 354 bp in length which encodes 118 amino acids.Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the VH gene was successfully expressed and purified from inclusion bodies.ELISA result also demonstrated that VH gene expressed products bind purified JEV.Conclusions The VH gene of monoclonal antibody 2F2 against JEV had been cloned.

The speciifc inhibition of siRNAs targeting 5' untranslated region of the enterovirus 71 genome / 临床儿科杂志

Objective To screen and identify effective small interfering RNA (siRNAs) targeting the conserved 5’ untrans-lated region (UTR) of the enterovirus 71 (EV71) genome. Methods Double-stranded siRNAs were designed to target the 5’UTR of the EV71 genome. The cytotoxicity effect of siRNAs on rhabdomyosarcoma (RD) cells was evaluated. The cytopathic effect on EV71-infected RD cells was observed under phase-contrast microscopy and the effective siRNAs were screened out by cell viability assay and real-time TaqMan RT-PCR assay. Results All the siRNAs did not exhibit any cytotoxic effects on the viability and growth of RD cells. Transfection of si-1 and si-2 targeting the 5’ UTR in EV71 genome into RD cells signiifcantly delayed and alleviated the cytopathic effects of EV71 infection, increased cell viability and reduced the EV71 RNA transcripts. And the inhibitory effect of si-1/si-2 on EV71 replication was sequence-speciifc. Conclusions The 2 siRNAs (si-1 and si-2) targeting the conserved 5’UTR of the EV71 genome may have broad spectrum antiviral effects on many epidemic EV71 strains.

Isolation and preliminary identification of 74×103 molecule as putative Japanese encephalitis virus receptor / 中华微生物学和免疫学杂志

Objective To isolate and identify the putative Japanese encephalitis virus (JEV) re-ceptors from C6/36 and Vero cells. Methods Molecules binding with JEV were isolated from C6/36 and Vero cells by co-immunoprecipitation (Co-IP) approach, identified by mass spectrometry, and detected by Western blot. The location of putative JEV receptor on cells membrane and the binding with JEV were ob-served by laser scanning confocal microscopy (LCM). Results Several molecules binding with JEV were isolated from C6/36 and Vero cells by Co-IP, and only one molecule was identified as heat shock cognate 70 (HSC70) by mass spectrometry. Antibody against HSC'70 was able to detect a 74 ×103 protein isolated by Co-IP from C6/36 and Vero cells membrane in Western blot assays. It was observed by LSCM that when JEV attached on the surface of C6/36 cells, JEV and HSCT0 protein were co-localization. Conclusion 74 x 103 molecular identified as HSC70 protein from C6/36 cells may be JEV receptor.