Brain-derived neurotrophic factor (BDNF) peptide antibodies: Characterization using a Vaccinia virus expression system

Abstract

We describe and characterize a series of polyclonal antibodies, generated against amino acid sequences unique to various regions within pro- and mature brain-derived neurotrophic factor (BDNF), a member of the highly conserved nerve growth factor (NGF) family of neurotrophins. Synthetic peptides were coupled to carrier proteins in the presence of glutaraldehyde to restrict the host animals immune response to epitopes that are compatible with aldehyde fixation. Initial screenings of the reactivity of the antisera were made on brain sections processed for immunohistochemistry after peptide injections into brain parenchyma. As a means of further characterizing these peptide antisera, we have evaluated the reactivity and specificity of the peptide antibodies in BHK cells expressing recombinant pro- and mature BDNF protein from a T7 RNA polymerase-driven Vaccinia virus system. Several of the antibodies strongly stained components of cells transfected with the BDNF gene but did not label wild-type cells nor cells containing only the expression vector. It has also been possible to detect differential compartmentalization of the BDNF protein at various stages of processing in the BHK cells, as well as in situ in cryostat sections of brain tissue, with antisera to the pro- and mature protein. We conclude that several of our antisera recognize not only the specific peptide immunogens but also what appears to be the corresponding protein native to neurons.