Characterization of specific IgE antibody related to antigen 5 of echinococcus granulosus

Anaphylactic reactions, such as urticaria, edema, respiratory symptoms, and anaphylactic shock often complicate the course of Cystic Echinococcosis [CE]. To investigate the role of the IgE immunoreactive antigen 5 [Ag 5] in the sero-positive patients with CE, we determined N-terminal of 57 kDa subunit of Ag5 responsible for IgE and C-terminal of this active antigen related to induction of IgG specifically. Immunoblotting analysis showed that specific IgE to 57-kDa subunit related to inter-chain disulphide band of two 22 kDa and 38-kDa component of Ag5 and conformational epitope on this subunits. In addition, since the 57 kDa component arise from the removal of the C-terminal portion of 22 kDa subunit of Ag5, thus IgE specifically recognized N-terminal of 22 kDa subunit which remain bounds to the other component, whereas IgG reacted with C-terminal of 38 kDa component of Ag5. Recognition of the specific binding site on the 57 kDa subunit of Ag5 could leads to understanding the mechanism regulating IgE/IgG production in some immune circumstances that IgE tends to some dominate, whereas in other IgG predominates

Evaluation of a native preparation of HCV core protein [2-122] for potential applications in immunization, diagnosis and mAb production

Infection with hepatitis C virus [HCV] is a worldwide problem. Among HCV proteins, core antigen [Ag], besides its importance for diagnostic application is a prime candidate for component of a vaccine. Herein, we report results of studies on production of the hydrophilic domain of core Ag [2-122] in native conformation by an arabinose induction system in E.coli and the primary characterization of this recombinant protein for applications in diagnosis, immunization and mAb production. Recombinant core [r-Core] was able to detect anti-core antibodies in HCV positive serum samples in a dilution rate of 1/3200. It was also capable to elicit a potent anti-HCV humoral immune response in BALB/c mice. Finally, we established two stable clones of hybridoma which shown to produce specific and sensitive mAbs against the core protein. HCV core was able to elicit a broad range of antibody specificities depending on the immunogen conformation. Therefore, it may be possible to get new mAbs with higher affinities towards native conformation of core Ag

Characterization of a monoclonal antiody specific for the parasite surface antigen-2 of leishmanie major

The Leishmania major Parasite surface Antigen-2 [PSA-2] is a family of glycoinositol phospholipids anchored glycoprotoins expressed in both promastigotes and amastigotes. Promastigote PSA-2 comprises three polypeptides with approximate molecular weight of 96, 80 and 50 kDa. Amastigote express a distinct but closely PSA-2 polypeptide with molecular weight of 50 kDa. In this study fusion of SP2/0 myeloma cells with immunized mice spleenocytes infected with promastigotes of L. major intraperitoneally resulted to a clone of hybridoma producing a specific antibody that only reacts with L. major parasite surface antigen [PSA-2]. This mAb showed no crossreactivity with either other Leishmania species including L. tropica, L. donovani and L. infantum or recombinant gp63. Western blot analysis of culture supernatant revealed multiple b and s with molecular weight of 50, 58, 80 and 96 kDa only in L. major

Preparation of monoclonal antibody against the common determinants of HBsAg

Subtype-specific monoclonal antibodies are valuable tools for structural analysis of hepatitis B virus surface antigens and epidemiological investigations. Nineteen hybridoma clones producing monoclonal antibodies [MAb] specific for different epitopes of hepatitis B surface antigens [HBsAg] were established from mice immunized with HBsAg of either ayw or adw subtype. The immunizing antigens were purified from serum of carrier individuals or extracts of transgenic plants by affinity chromatography using polyclonal anti-HBs antibody. The specificity of MAbs was determined by enzyme-linked immunosorbent assay and immunoblotting using a panel of purified HBsAg of given subtypes. Out of the 19 MAbs, 9 were found to be specific for the common "a" determinant, and the remainders were specific for either "d" [n=2], "y" [n=5] or "w" [n=3] subtypic determinants. None of the subtype-specific MAbs displayed cross-reactivity with the other major subtypic epitopes. These MAbs have potential as monospecific reagents for subtyping HBsAg in carrier individuals for epidemiological and experimental investigations