BACKGROUND Contraceptive vaccines can provide valuable alternatives to current methods of contraception. We describe here the development of sperm-reactive human single chain variable fragment (scFv) antibodies of defined sperm specificity for immunocontraception. METHODS Peripheral blood leukocytes (PBL) from antisperm antibody-positive immunoinfertile and vasectomized men were activated wit...

Single-chain variable fragments (scFvs) of anti-neuraminidase antibody NC10 were constructed by joining the VH and VL domains with 10-residue (Gly4Ser)2 and five-residue (Gly4Ser) linkers; a zero-residue linker scFv was constructed by joining the C-terminal residue of the VH domain to the N-terminus of the VL domain. The scFv with the 10- and five-residue linkers exclusively formed dimeric anti...

CD33 is a cell surface glycoprotein expressed on cells of myelomonocytic lineage, leukaemic cells, but not haematopoietic stem cells. By virtue of its expression pattern, CD33 has become a popular target for new immunotherapeutic approaches to treat acute myeloid leukaemia. The methylotrophic yeast Pichia pastoris strain KM71H was used to produce an anti-CD33 single chain variable fragment (scF...

Aim: Immunotoxins are proteins that consist of an antibody fragment linked to a toxin, used as agents for targeted therapy of cancers. Although the most potent immunotoxins are made from bacterial and plant toxins, obstacles which contribute to poor responses are immunogenicity in patients and rapid development of neutralizing antibodies. In the present study we proposed a new therapeutic immun...

A well-known complication of factor VIII replacement therapy in patients with hemophilia A is the development of inhibitory antibodies. Several studies have demonstrated the presence of a binding site for factor VIII inhibitors in the A3 domain. Six different human monoclonal single-chain variable domain antibody fragments (scFv) directed toward the A3-C1 domains of factor VIII have been isolat...

Combinatorial phage display technology offers a new possibility for making human antibodies which could be used in immune therapy. We explored the use of this technology to make human scFvs specific for crotoxin, the main toxic component of the venom of the South-American rattlesnake Crotalus durissus terrificus. Crotoxin, a phospholipase A2 neurotoxin constituted by the association of two subu...

Adult T-cell leukemia (ATL) is an intractable blood cancer caused by the infection of human T-cell leukemia virus type-1, and effective medical treatment is required. It is known that the structure and expression levels of cell surface sugar chains vary depending on cell states such as inflammation and cancer. Thus, it is expected that the antibody specific for ATL cell surface sugar chain woul...

Plants do not produce antibodies. However, plants can correctly assemble functional antibody molecules encoded by mammalian antibody genes. Many plant diseases are caused by pathogen toxins. One such disease is the soybean sudden death syndrome (SDS). SDS is a serious disease caused by the fungal pathogen Fusarium virguliforme. The pathogen, however, has never been isolated from diseased foliar...

The presence of erythropoietin (Epo) receptors on cells besides red blood cell precursors, such as cancer cells or megakaryocyte precursors, can lead to side effects during Epo therapy including enhanced tumor growth and platelet production. It would be ideal if the action of Epo could be limited to erythroid precursors. To address this issue, we constructed single-chain variable fragment (scFv...

We have developed a combinatory antibody-antigen microarray for direct screening of multiple single-chain fragment variable (scFv) clones with no need for pre-purification or enrichment before screening. The straightforward workflow allows for early selection of binders to predefined peptide and glycopeptide targets. A capture antibody is contact printed on microarray slides, side by side with ...