DETECTION OF MICROSPORIDIA SPORE-SPECIFIC ANTIGENS BY MONOCLONAL-ANTIBODIES

Microsporidia (phylum Microspora) are unicellular parasites commonly f ound in invertebrates, fish, and laboratory animals; however, microspo ridiosis is an emerging problem in patients with the acquired immunode ficiency syndrome (AIDS), The infective stage of these parasites is th e spore, which possesses a rigid cell wall that protects the parasite outside its host, Little is known about their antigenic composition, S ensitive, reliable, and easily performed methods for identification an d speciation are generally not available, Here, we report the producti on of 21 MAbs specific to spore antigens of several species of Microsp oridia, MAbs were generated to purified spores of Encephalitozoon inte stinalis and Encephalitozoon heliem, and their reactivities were teste d against spores and intracellular developing forms of E., intestinali s, E, hellem, Encephalitozoon cuniculi, and Vittaforma corneae, Both s pecies-specific and broad-reactivity MAbs were produced. Five MAbs rea cted against the spores of all four species tested: 7 with 3 species, 6 with 2 species, 1 with E. intestinalis, and 4 with the polar tube of all species. Immunoelectron microscopy confirmed the reactivity of sp ecific MAbs to the spore wall or the polar tube. These MAbs reacted to a few antigens as determined by Western blot, and none of the epitope s were periodate-sensitive. These MAbs may be useful in the diagnosis and speciation of Microsporidia as well in the purification, cloning, and detection of these antigens.