Abstract
The localization and biochemical nature of antigens found in the electron-lucent layer (ELL) of Pneumocystis carinii cysts using polyclonal rabbit antibodies are described. These antigens, specific for the cystic stages of the parasite, were shared by organisms from different hosts, suggesting that they represent functionally important components of the cyst cell wall. The binding sites were situated on an interwoven net of fibrils in the ELL produced by mild to strong proteolysis. Degradation of this residue by glucanase and chitinase confirms that this layer contains branched glucan and chitin. In contrast, the prompt susceptibility of the polysaccharide-rich ELL to proteolysis reveals that proteins are also relevant in building up the cyst-wall glucan skeleton. It is therefore concluded that the formation of the Pneumocystis cyst wall shows differences to the typical fungal cell-wall architecture. The taxonomical debate regarding this unique protist is ongoing, and consideration of these immunological and morphological findings may be useful for the study of the biology and phylogeny of Pneumocystis.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 12 June 1996 / Accepted: 27 August 1996
Rights and permissions
About this article
Cite this article
Roth, A., Wecke, J., Karsten, V. et al. Light and electron microscopy study of carbohydrate antigens found in the electron-lucent layer of Pneumocystis carinii cysts. Parasitol Res 83, 177–184 (1997). https://doi.org/10.1007/s004360050229
Issue Date:
DOI: https://doi.org/10.1007/s004360050229