Tubuloreticular inclusions and paired cisternae induced in human lymphocytes cultured with Staphylococcus aureus Cowan 1.
Tubuloreticular inclusions (TRI) and paired cisternae (PC) were induced in lymphocytes of normal individuals after incubation with Staphylococcus aureus Cowan 1. TRI were initially detected in lymphoid cells on day 2 (48-h culture). The frequency of TRI-positive cell sections on day 5 increased about twofold over those on days 2-4. On day 7, TRI were predominantly seen in lymphoplasmacytoid cells or plasmacytoid cells, with an incidence of up to 18% of sections. The regions in these cells were most extensive and anastomosed with the cisternae of adjacent well-developed rough endoplasmic reticulum (RER). TRI formation appears not to be essential for mitogen-induced B-cell differentiation to plasmacytoid cells, because pokeweed mitogen (PWM) failed to induce TRI. The diverse expressions of TRI induction between these two mitogens may be due to a difference in B-cell activation mechanisms. Paired cisternae were observed in a great majority of mitotic cells at various stages. These were encountered most frequently on day 4. PC were also seen in the PWM-stimulated culture. Our observations suggest that PC formation may be related to new formation of RER as well as to reconstruction of the nuclear envelope.
D002478:Cells, Cultured; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000382:microbiology / Q000648:ultrastructure*; D008854:Microscopy, Electron; D009940:Organoids / Q000648:ultrastructure*; D013211:Staphylococcus aureus