Animals ; Evolution, Molecular ; Glycoproteins ; chemistry ; genetics ; immunology ; metabolism ; Mutation ; Phylogeny ; Rabies virus ; genetics ; physiology ; Viral Proteins ; chemistry ; genetics ; immunology ; metabolism

Peanut is one of the most popular foods in the world due to its high nutrition; however, it contains multiple seed storage proteins which are identified as allergens and hence are the most common cause of life-threatening, IgE-mediated anaphylaxis among the hypersensitive individuals. Three peanut proteins, Arachis hypogaea allergy 1, 2, 3 (Ara h 1, Ara h 2 and Ara h 3), which have the common biochemical characteristics like resistance to proteases and heat, are considered as the major allergens because they are recognized by serum IgE from a peanut-allergic patient population. The linear IgE-binding epitopes in the allergens lay the foundation of the anaphylaxis in the peanut-allergic individuals. Peanut allergy is often a life-long problem, so many investigators are focusing on decreasing clinical reactivity. In this review, the latest advances in the researches on biochemical characteristics, structure and function of the three major allergens were described and particular attention was given to the immunity properties of the three allergens. The future research directions were also discussed.
2S Albumins, Plant ; chemistry ; genetics ; immunology ; Animals ; Antigens, Plant ; chemistry ; genetics ; immunology ; Arachis ; chemistry ; DNA ; genetics ; Glycoproteins ; chemistry ; genetics ; immunology ; Humans ; Immunoglobulin E ; genetics ; Plant Proteins ; chemistry ; genetics ; immunology

Fertilin beta plays an important role in fertilization by its disintegrin domain as a sperm-specific antigen. This paper reviews its structure, localization and roles in fertilization, and suggests that fertilin beta, as an important target antigen, has a very promising value in the development of human immunocontraceptive vaccine.
ADAM Proteins ; Animals ; Contraception, Immunologic ; Fertilins ; Fertilization ; Humans ; Male ; Membrane Glycoproteins ; chemistry ; genetics ; physiology ; Metalloendopeptidases ; chemistry ; genetics ; physiology ; Vaccines ; immunology

Influenza virus is the causative agent of the seasonal and occasional pandemic flu. The current H1N1 influenza pandemic, announced by the WHO in June 2009, is highly contagious and responsible for global economic losses and fatalities. Although the H1N1 gene segments have three origins in terms of host species, the virus has been named swine-origin influenza virus (S-OIV) due to a predominant swine origin. 2009 S-OIV has been shown to highly resemble the 1918 pandemic virus in many aspects. Hemagglutinin is responsible for the host range and receptor binding of the virus and is therefore a primary indicator for the potential of infection. Primary sequence analysis of the 2009 S-OIV hemagglutinin (HA) reveals its closest relationship to that of the 1918 pandemic influenza virus, however, analysis at the structural level is necessary to critically assess the functional significance. In this report, we report the crystal structure of soluble hemagglutinin H1 (09H1) at 2.9 Å, illustrating that the 09H1 is very similar to the 1918 pandemic HA (18H1) in overall structure and the structural modules, including the five defined antiboby (Ab)-binding epitopes. Our results provide an explanation as to why sera from the survivors of the 1918 pandemics can neutralize the 2009 S-OIV, and people born around the 1918 are resistant to the current pandemic, yet younger generations are more susceptible to the 2009 pandemic.
Animals ; Cloning, Molecular ; Crystallography, X-Ray ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; isolation & purification ; Influenza A Virus, H1N1 Subtype ; chemistry ; genetics ; immunology ; Models, Molecular ; Protein Conformation ; Swine ; virology

A monoclonal antibody (8H5), which showed strong neutralization activity against 33 strains of H5N1 viruses isolated from hosts at various regions from 2002 to 2006, was characterized in our lab recently. This result indicated the presence of highly conserved neutralizing site on hemagglutinin (HA) of various H5N1 subtypes. In the present study, the peptide phage display technique was applied to generate mimotope of the conserved neutralizing epitope recognized by 8H5 mAb. Five peptides displayed on phage were identified to specifically bind to 8H5 mAb. One of the five peptides, 123, was further displayed on the virus-like particle assembled from aa 1-149 fragment of HBcAg. The chimeric particle HBc-T123 conserved the specific binding to 8H5 mAb, and competed with H5N1 viruses for 8H5 mAb. The antiserum induced by HBc-T123 intensively stained on SF21 cells infected by recombinant baculovirus containing HA gene of YU22 virus, indicating the production of cross-reactive antibody to H5N1 HA.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; immunology ; Epitopes ; chemistry ; genetics ; immunology ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; Humans ; Influenza A Virus, H5N1 Subtype ; chemistry ; genetics ; immunology ; Influenza, Human ; virology ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Peptide Library

The molecular characterization and phylogenetic analysis of hemagglutinin (HA) genes of human influenza H3N2 viruses in Guangdong, China from 2007 to 2010 were studied in this study. By space-time sampling of strains, the HA genes of H3N2 strains from Guangdong were sequenced and searched from Internet, and then the variation and evolution of HA genes were conducted by Lasergene 7.1 and Mega 5.05 and evolutionary rates were analyzed by epidemiological data. The phylogenetic tree was established by alignment of 17 Guangdong strains and 26 global reference strains. Ks rates and Ka rates of HA genes were 2.06 x 10(-3)-2.23 x 10(-3) Nt/Year and 1.05 x 10(-3)-1.21 x 10(3) Nt/Year during 2007-2010, while the velocity of HA1 evolution of Ka was 3. 13 times than that of HA2 evolution. Compared with HA of vaccine strain A/Perth/16/2009, the genetic homologies of Guangdong strains in 2009 reached to 98.8%-99.7% and of Guangdong strains in 2010 reached to 98.0%-98.4%. There were some amino acid substitutions in five epitope regions of HA1 during 2007-2010, especially in B region (N160K) and D region (K174R/N); the K189E/N/Q and T228A in RBS (receptor-binding site) occurred in 2010 as two glycoproteins sites substituted impacted on the HA1 antigenicity. The antigenicity of epidemic H3N2 strains in 2010 was to some degree different that of the vaccine strain A/ Perth/16/2009. According to that there were variations of B and D epitopes and two sites of RBS and two glycoprotein in Guangdong H3N2 HA1 genes, WHO/ CDC should recommend new representative strains during 2011-2012 influenza seasons if H3N2 HA genes further evolve in the near future.
Amino Acid Substitution ; China ; Disulfides ; chemistry ; Epitopes ; genetics ; Evolution, Molecular ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; Mutation ; Phylogeny

The N-terminal segment (FR-1) of the heavy chain (VH) of antibodies may have a great impact on IgG secretion in Escherichia coli and other hosts. Decrease in secretion may be caused by a single amino acid change in the framework region. To investigate the high antibody expression in mammalian cells, we designed the site-directed mutagenesis of the FR-I of the pCMV-RV/VH gene,which expressed the immunoglobulin heavy chain of human anti-Rabies virus antibody. Mutating Glu (H6) to Gln could improve both antibody secretion and affinity. The immunofluorescence assay indicated that both the secretion-deficient antibodies and the secretion- efficient antibodies could be transcribed and translated intracellularly, and led into ER,then transferred to Golgi apparatus,and the difference in secretion may relate to the contribution of the FR-I to the folding and assembly of the antibody. In this study, we have confirmed experimentally that the nature of residues H6 in antibody heavy chains indeed determines the antibody secretion in mammalian cells. These results also provide the basis for antibody production.
Animals ; Antibodies ; genetics ; immunology ; metabolism ; Antibodies, Viral ; genetics ; immunology ; metabolism ; Antibody Affinity ; Biological Transport ; COS Cells ; Cercopithecus aethiops ; Cytomegalovirus ; genetics ; Endoplasmic Reticulum ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique ; Glycoproteins ; genetics ; immunology ; Golgi Apparatus ; metabolism ; Humans ; Immunoglobulin Fragments ; genetics ; immunology ; Immunoglobulin Heavy Chains ; chemistry ; genetics ; immunology ; Immunoglobulin Variable Region ; chemistry ; genetics ; immunology ; Mutagenesis, Site-Directed ; Plasmids ; genetics ; Rabies virus ; genetics ; immunology ; metabolism

Since March 2009, pandemic A/H1N1/2009 influenza virus has been spreading throughout many countries including China. The emerged virus caused great harm to human health and social economy. Hemagglutinin (HA) is the most important viral surface glycoprotein, mainly possessing three kinds of functions: (1) binding to host cell receptor, (2) triggering the fusion between viral envelop and target cell membrane, (3) stimulating the body to generate the neutralizing antibody. Advances in the structure, primary function, evolution and antigenicity of pandemic A/H1N1/2009 influenza virus HA protein are reviewed in this paper.
Animals ; Evolution, Molecular ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; metabolism ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; pathogenicity ; physiology ; Influenza, Human ; epidemiology ; virology ; Pandemics

OBJECTIVETo understand the molecular mechanisms of hantavirus assembly and maturation by stably expressing the intracellular antibodies to hantavirus glycoprotein G1 and G2 in endoplasmic reticulum (ER) and cytoplasm (Cyto) of Vero E6 cell.

METHODSThe genes of VH and VL of antibodies against glycoprotein of hantavirus were amplified by PCR and cloned into pOPE 101-215 (Yol) vector. The G1 and G2 proteins specific ScFv genes were first expressed in E.coli and the function and binding properties were identified. The gene of ScFv were further inserted into intracellular expression vectyrs pEF/ myc/ ER and pEF/ myc/ CYTO vector and transfected Vero E6 cell. The clonal cell line which stabl expresses ScFv were isolated under the pressure of G418.

RESULTSThe ScFv genes of hantavirus G1 and G2 specific antibodies were successfully expressed in subcellular compartment ER and Cyto of Vero E6 cells and specifically targeted G1 and G2 protein after virus infection of the cells.

CONCLUSIONSThe recombination of intrabody to Hantann virus glycoprotein was constructed successfully, and it may provide basic material for the studying antiviral gene therapy and the molecular mechanism of viral replication and infection.

Animals ; Antibodies, Viral ; biosynthesis ; genetics ; immunology ; Cercopithecus aethiops ; Cloning, Molecular ; Endoplasmic Reticulum ; virology ; Glycoproteins ; biosynthesis ; genetics ; immunology ; Hantaan virus ; chemistry ; genetics ; immunology ; Humans ; Polymerase Chain Reaction ; Transfection ; Vero Cells ; Viral Envelope Proteins ; biosynthesis ; genetics ; immunology

Plants are known to be efficient hosts for the production of mammalian therapeutic proteins. However, plants produce complex N-glycans bearing β1,2-xylose and core α1,3-fucose residues, which are absent in mammals. The immunogenicity and allergenicity of plant-specific Nglycans is a key concern in mammalian therapy. In this study, we amplified the sequences of 2 plant-specific glycosyltransferases from Nicotiana tabacum L. cv Bright Yellow 2 (BY2), which is a well-established cell line widely used for the expression of therapeutic proteins. The expression of the endogenous xylosyltranferase (XylT) and fucosyltransferase (FucT) was downregulated by using RNA interference (RNAi) strategy. The xylosylated and core fucosylated N-glycans were significantly, but not completely, reduced in the glycoengineered lines. However, these RNAi-treated cell lines were stable and viable and did not exhibit any obvious phenotype. Therefore, this study may provide an effective and promising strategy to produce recombinant glycoproteins in BY2 cells with humanized N-glycoforms to avoid potential immunogenicity.
Amino Acid Sequence ; Blotting, Western ; Carbohydrate Sequence ; Cell Line ; Cloning, Molecular ; DNA, Complementary ; genetics ; Down-Regulation ; Epitopes ; genetics ; immunology ; Fucose ; metabolism ; Fucosyltransferases ; chemistry ; deficiency ; genetics ; immunology ; Glycoproteins ; chemistry ; genetics ; immunology ; Molecular Sequence Data ; Pentosyltransferases ; chemistry ; deficiency ; genetics ; immunology ; Polysaccharides ; chemistry ; immunology ; Protein Engineering ; methods ; RNA Interference ; Species Specificity ; Tobacco ; cytology ; genetics ; Xylose ; metabolism