TY - JOUR
T1 - Tetraspanin-2 localisation in high pressure frozen and freeze-substituted Schistosoma mansoni adult males reveals its distribution in membranes of tegumentary vesicles
AU - Schulte, Leigh
AU - Lovas, Erica
AU - Green, Kathryn
AU - Mulvenna, Jason
AU - Gobert, Geoffrey N.
AU - Morgan, Garry
AU - Jones, Malcolm K.
PY - 2013/9
Y1 - 2013/9
N2 - The tegument, or body wall, of schistosomes is the primary tissue for host interaction and site targeted schistosome vaccination. However, many aspects of the cell biology, particularly differentiation and maintenance, remain uncharacterised. A leading vaccine candidate, Schistosoma mansoni tetraspanin 2 has proven efficacy in experimental models, but its function, precise subcellular location in the tegument and role in tegument biology is not well understood. A primary question is whether this molecule is a true surface molecule, that is, whether it appears within the apical membrane of the tegument. Hitherto, the target sequence for antibody localisation studies had not been available for advanced subcellular localisation studies, such as immuno-electron microscopy, due to aldehyde sensitivity. To circumvent this problem, we adapted the methods of high pressure freezing and cryosubstitution with uranyl acetate for immuno-electron microscopy. The tri-dimensional structure of tegument membranes was resolved using electron tomography. Immunolocalisation of Schistosoma mansoni tetraspanin 2 demonstrates that the molecule is localised to tegument membrane compartments, but predominantly within internal structures associated with surface invaginations and internal vesicles. Surprisingly, no label was found at the virtual surface of the parasite. The significance of this localisation pattern is discussed.
AB - The tegument, or body wall, of schistosomes is the primary tissue for host interaction and site targeted schistosome vaccination. However, many aspects of the cell biology, particularly differentiation and maintenance, remain uncharacterised. A leading vaccine candidate, Schistosoma mansoni tetraspanin 2 has proven efficacy in experimental models, but its function, precise subcellular location in the tegument and role in tegument biology is not well understood. A primary question is whether this molecule is a true surface molecule, that is, whether it appears within the apical membrane of the tegument. Hitherto, the target sequence for antibody localisation studies had not been available for advanced subcellular localisation studies, such as immuno-electron microscopy, due to aldehyde sensitivity. To circumvent this problem, we adapted the methods of high pressure freezing and cryosubstitution with uranyl acetate for immuno-electron microscopy. The tri-dimensional structure of tegument membranes was resolved using electron tomography. Immunolocalisation of Schistosoma mansoni tetraspanin 2 demonstrates that the molecule is localised to tegument membrane compartments, but predominantly within internal structures associated with surface invaginations and internal vesicles. Surprisingly, no label was found at the virtual surface of the parasite. The significance of this localisation pattern is discussed.
KW - Cryo-electron microscopy
KW - Electron tomography
KW - Schistosoma mansoni
KW - Tegument
KW - Tetraspanins
UR - http://www.scopus.com/inward/record.url?scp=84881550105&partnerID=8YFLogxK
U2 - 10.1016/j.ijpara.2013.04.003
DO - 10.1016/j.ijpara.2013.04.003
M3 - Article
AN - SCOPUS:84881550105
SN - 0020-7519
VL - 43
SP - 785
EP - 793
JO - International Journal for Parasitology
JF - International Journal for Parasitology
IS - 10
ER -