Monoclonal antibodies (mAbs) contribute a lot to the development of numerous fields in life science as a pivotal tool in modern biological research. Development of the PCR methods and maturation of antibody production have made it possible to generate mAbs from single human B cells by single cell RT-PCR with successional cloning and expression in vitro. Compared to traditional monoclonal antibody technologies, single B cell technologies require relatively fewer cells, which are highly efficient in obtaining specific mAbs in a rapid way with preservation of the natural heavy and light chain pairing. With so many advantages, single B cell technologies have been proved to be an attractive approach for retrieval of naive and antigen-experienced antibody repertoires generated in vivo, design of rationale structure-based vaccine, evaluation and development of basic B cell biology concepts in health and autoimmunity, and prevention of infectious diseases by passive immunization and therapy for disorders. Accordingly, this review introduced recent progresses in the single B cell technologies for generating monoclonal antibodies and applications.
Antibodies, Monoclonal ; biosynthesis ; genetics ; immunology ; Antibody Specificity ; B-Lymphocytes ; cytology ; immunology ; metabolism ; Humans ; Immunologic Techniques

A novel human ScFv H12 against SARS-CoV has been selected from a SARS immune library. In order to produce a large amount of ScFv H12, pET28a-H12 expression vector was constructed and ScFv H12 was expressed at yield about 30% of total proteins in E. coli . Here two different refolding procedures were used to refold ScFv H12 from inclusion body: gel filtration chromatography and dilution. The results showed that ScFv H12 could be efficiently refolded by both procedures. However, the refolding via gel filtration was 1.5 time more effective than that of dilution. The affinity of ScFv H12 to SARS-CoV virion was detected as Kd = 73.5 nmol/mL.
Antibodies, Monoclonal ; biosynthesis ; genetics ; Antibodies, Viral ; immunology ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin Fragments ; biosynthesis ; genetics ; immunology ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; immunology ; Inclusion Bodies ; genetics ; immunology ; Protein Renaturation ; Recombinant Proteins ; biosynthesis ; chemistry ; immunology ; SARS Virus ; immunology

OBJECTIVETo develop human recombinant neutralizing IgG monoclonal antibodies to hepatitis A virus (HAV) by baculovirus expression system.

METHODSThe heavy and light chain genes of two human-derived neutralizing Fab antibodies to HAV were cloned into baculovirus expression vector Pac-kappa-Fc and Pac-L-Fc, and further expressed in insect cells as IgG antibodies. The IgG products were purified and well characterized.

RESULTSThe baculovirus expressed McAb HAFc16 fully retained the specificity of binding to hepatitis A virus and the competition with mouse anti-hepatitis A virus McAb using ELISA. The viral neutralization assay in vitro demonstrated the retention of antibody function after expression of the human antibody in insect cells. The other expressed antibody HAFc78 also has the neutralizing activity but it is directed against different epitopes of HAV when compared with HAFc16.

CONCLUSIONThe recombinant baculovirus/insect cells expressed human neutralizing IgG antibodies to hepatitis A virus retained all biological functions specific for hepatitis A virus. The results provided the possibility of using these antibodies to rapidly protect high risk or early exposure populations from hepatitis A virus infection.

Antibodies, Monoclonal ; biosynthesis ; immunology ; Baculoviridae ; genetics ; Hepatitis A virus ; immunology ; Hepatitis Antibodies ; biosynthesis ; immunology ; Humans ; Immunoglobulin Fab Fragments ; biosynthesis ; immunology ; Immunoglobulin G ; biosynthesis ; immunology ; Immunoglobulin Heavy Chains ; genetics ; Immunoglobulin Light Chains ; genetics ; Recombinant Proteins ; biosynthesis ; immunology

Transmembrane protein p185 (the product of Her2/c-erbB-2 gene) is a member of the epidermal growth factor receptor (EGFR) family. Its overexpression was found in about 30% of breast cancer. It is essential to obtain soluble extracellular domain (ECD) of p185, especially disulfide bond rich domains, for identifying the epitopes of anti-p185 antibodies and researching the interrelationship between the antigen and antibody. The disulfide bond rich domain I-II and domain IV of p185 ECD were amplified from plasmid pBabe/erbB-2 by PCR respectively. These two fragments were inserted into pGEX/4T-1 vector, transfected into E. coli Origami B (DE3) pLysS and expressed inductively by low concentration of IPTG and low temperature overnight. After the pressure lysis of cells, the supernatants were analyzed by SDS-PAGE and the result demonstrated that this GST-fusion protein was expressed solubly in the amount of 10-15 mg/L. By the ELISA, Western blot and other immunological assays, the fusion proteins and their GST cut-off derivates both showed binding activities with several anti-p185 antibodies respectively. These results indicated that it was a feasible and effectual method to express disulfide bond rich domain I-II and domain IV of p185 ECD and this method may also be used to express other disulfide bond rich proteins.
Antibodies, Monoclonal ; immunology ; Disulfides ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Receptor, ErbB-2 ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Solubility ; Transfection

For studying the expression and distribution of angiotensinogen (AGT), the C-teminus of rat AGT gene was expressed in E.coli. Rabbits were immunized with expressed AGT protein and sera from different rabbits were raised. ELISA showed a high titre (1:25600) of the antiserum. With the antiserum, Western blotting recognized not only the prokaryotic expressed AGT, but also the endogenous AGT protein in liver tissue of both rats and humans. Using this antiserum, immunohistochemistry showed the expression of AGT protein in islet cells of human pancreas as well as in epithelium of human bile duct. These results suggest that the prokaryotic expressed AGT protein is an effective immunogen for the preparation of anti-AGT antiserum. Our present work provides an important tool for study of the pathophysiological role of AGT as well as local renin-angiotensin system.
Angiotensinogen ; genetics ; immunology ; Animals ; Antibodies, Monoclonal ; biosynthesis ; Escherichia coli ; genetics ; metabolism ; Humans ; Immune Sera ; biosynthesis ; immunology ; Immunization ; Rabbits ; Rats ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Renin-Angiotensin System ; physiology

This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.
Animals ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Cell Line ; Chimera ; Cloning, Molecular ; Humans ; Lentivirus ; genetics ; metabolism ; Mice ; Receptor, ErbB-2 ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Transfection

deltaFosB, a naturally occurring truncated isform of fosB gene, existed in many tissues stably and played an important role in formation and differentiation of adipocyte and osteoblast. deltaFosB may be related to the metabolism of calcium in bone and mammary gland and regulate the signal pathway of calcium transfer from bone to mammary gland. We first sub-cloned deltafosB gene of goat into the vector pET32a to construct prokaryotic expression vector pET32a-deltafosB. Then we induced for deltafosB gene expression efficiently by IPTG. Finally we immunized the adult rabbits with purified recombinant deltaFosB to prepare rabbit anti-goat deltaFosB polyclonal antibody. iELISA analysis showed the antibody with the titer of 1:51 200, and Western blotting result showed that the antibody could specifically detect the deltaFosB protein expressed in prokaryotic cell and HEK-293 cell, respectively. Further Western blotting assay showed that deltaFosB expressed in various tissues of goat in vivo.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Goats ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVETo obtain recombinant N-and C-terminal of FKBP38 and prepare anti-FKBP38 polyclonal antibody for Western blotting (WB), immunohistochemical (IHC) and immunofluorescence (IF) analyses.

METHODSThe N-terminal (1-207 aa) and C-terminal (209-387 aa) cDNA of FKBP38 were sub-cloned from the full-length cDNA of FKBP38 and ligated to prokaryotic expression plasmid pGEX-6P-1 for construction of the recombinant vectors pGEX-6P-1-FKBP38-N and pGEX-6P-1-FKBP38-C. After sequencing, the recombinant vectors were transformed into E.coli BL21 and GST-tagged FKBP38-NT and FKBP38-CT were induced by IPTG. The proteins were purified by Glutathione affinity chromatography column and characterized by SDS-PAGE. Rabbits were immunized with the purified recombinant protein to prepare the antiserum, which were analyzed by WB, IHC and IF.

RESULTSThe recombinant vectors pGEX-6P-1-FKBP38-N and pGEX-6P-1-FKBP38-C were successfully constructed. After IPTG induction, the E.coli transformed with these plasmids expressed GST-tagged protein, which was successfully purified. Western blotting demonstrated that the purified antibody could specifically bind to FKBP38 in various cell lines. Immunofluorescence assay showed that FKBP38 was located mainly on the mitochondria. Immunohistochemical analysis revealed cytoplasmic location of FKBP38 in breast cells.

CONCLUSIONWe successfully expressed and purified N- and C-terminal of FKBP38, and FKBP38 polyclonal antibody we prepared can specifically recognize FKBP38 in SB, IF and IHC assays, which facilitates further functional investigation of FKBP38.

Antibodies, Monoclonal ; biosynthesis ; Fluorescent Antibody Technique ; Genetic Vectors ; genetics ; Humans ; Immunohistochemistry ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Tacrolimus Binding Proteins ; biosynthesis ; genetics ; immunology

IL-17 Receptor D (IL-17 RD) is a cytokine receptor that mediates IL-17 signaling and plays an important role in responding to the invasion of extracellular pathogens and many inflammatory and autoimmune diseases such as rheumatoid arthritis. In this study we report the generation of a mouse monoclonal antibody against human IL-17 RD. The recombinant human IL-17RD extracellular domain (hIL-17RD-ECD) was produced in the baculovirus expression system and purified from culture medium of sf9 insect cells. The purified protein was used as a T-dependent antigen to immune Balb/C mice. B cells from the spleen of immunized mice were fused with murine cell SP2/0. Hybridoma cell lines were screened for the production of the monoclonal antibody against hIL-17-RD-ECD using ELISA. A hybridoma cell line 1F8 was found to have a high production of the antibody, which was further confirmed for the specificity by both western blot and ELISA analyses. The monoclonal antibody obtained from hybridoma 1F8 was characterized to be IgG1+Kappa subclass. This study provided a base for the further therapeutic application of the antibody on the autoimmune disease including rheumatoid arthritis.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Baculoviridae ; Humans ; Insecta ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Receptors, Interleukin-17 ; biosynthesis ; genetics ; immunology ; Recombinant Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVETo obtain the monoclonal antibody against hexon protein of human adenovirus.

METHODSBALB/c mice were immunized with purified recombinant hexon protein, and the spleen cells of the mice were isolated and fused with myloma cells. Four hybridoma cell strains were screened by indirect ELISA and cultured, and the sensitivity, specificity and virus neutralizing activity were analyzed with ELISA, Western blotting and neutralizing test.

RESULTSThe mouse ascites produced by these hybridoma cells contained specific monoclonal antibodies against hexon protein of human adenovirus as identified by ELISA and Western blot, and the antibody generated by 4C6 strain showed human adenovirus type 3-neutralizing activity.

CONCLUSIONThe monoclonal antibodies against hexon protein with high specificity have been successfully obtained, and these antibodies can be useful in developing assays for early diagnosis of HAdV3 infection and also in study of therapeutic drugs of the infection.

Adenoviruses, Human ; chemistry ; immunology ; Animals ; Antibodies, Monoclonal ; biosynthesis ; immunology ; Antibodies, Viral ; biosynthesis ; immunology ; Blotting, Western ; Capsid Proteins ; biosynthesis ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; genetics ; Humans ; Hybridomas ; secretion ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; immunology