The entry of Theileria parva sporozoites into bovine lymphocytes: evidence for MHC class I involvement

• Published in: The Journal of cell biology 1991-04, Vol.113 (1), p.87-101
• Main Authors: Shaw, M.K. (International Laboratory for Research on Animal Diseases, Nairobi, Kenya), Tilney, L.G, Musoke, A.J
• Format: Article
• Language: English
• Subjects: Actins - physiology; Animals; Antibodies, Monoclonal; Apicomplexa - growth & development; Apicomplexa - ultrastructure; Azides - pharmacology; B lymphocytes; Biological and medical sciences; BOVIN; Cattle; Cell Membrane - ultrastructure; Cell membranes; Cells; CITOLOGIA; Cytochalasins; Cytochalasins - pharmacology; CYTOLOGIE; ENFERMEDADES DE LOS ANIMALES; ESTRUCTURA CELULAR; ETAPAS DEL DESARROLLO ANIMAL; Fundamental and applied biological sciences. Psychology; GANADO BOVINO; GLOBULINAS; GLOBULINE; Histocompatibility Antigens Class I - physiology; Histocompatibility Antigens Class II - physiology; In Vitro Techniques; Life cycle. Host-agent relationship. Pathogenesis; LINFOCITOS; LYMPHOCYTE; Lymphocytes; Lymphocytes - immunology; Lymphocytes - parasitology; Lymphocytes - ultrastructure; MALADIE DES ANIMAUX; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Microscopy, Electron; Molecules; Parasite hosts; Parasites; PODER PATOGENO; POUVOIR PATHOGENE; Protease Inhibitors - pharmacology; Protozoa; RELACIONES HUESPED PARASITO; RELATION HOTE PARASITE; SISTEMA MHC; SPOROZOA; Sporozoites; STADE DE DEVELOPPEMENT ANIMAL; STRUCTURE CELLULAIRE; SYSTEME MHC; Temperature; THEILERIA PARVA; Theileriasis - parasitology; Ungulates; Vacuoles - ultrastructure
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.113.1.87

We have examined the process of Theileria parva sporozoite entry into susceptible bovine lymphocytes and have begun to identify one of the possible molecular interactions involved in the process. The entry process involves a defined series of events and we have used a number of experimental procedures in combination with a method of quantitation to examine various aspects of this process. T. parva sporozoites are nonmotile organisms and the initial sporozoite-lymphocyte interaction is a chance event which can occur at 0-2 degrees C. All subsequent stages in the process are temperature dependent, require the participation of live intact sporozoites and host cells, and involve some cytochalasin-inhibitable rearrangement of the host cell surface membrane or cytoskeleton. Sporozoite entry can be inhibited by antibodies (mAbs) reactive with major histocompatibility complex (MHC) class I molecules (IL-A 19, IL-A 88) and with beta 2 microglobulin (B1G6), whereas mAbs reactive with MHC class II molecules (IL-A 21, J 11), and a common panleucocyte surface antigen, (IL-A 87; a bovine equivalent of CD 11a) have no effect. These results indicate that MHC class I molecules play a role in the process of T. parva sporozoite entry into bovine lymphocytes although as yet the precise role has not been determined. Once internalized within the lymphocyte, a process that takes 3 min at 37 degree C, the sporozoite rapidly escapes from the encapsulating host cell membrane; a process which occurs concurrently with the discharge of the contents of the sporozoite rhoptries and microspheres. The intracytoplasmic parasite is covered by a layer of sporozoite-derived fuzzy material to which host cell microtubules rapidly become associated