Interaction between cytolytic T-cells and immobilized renal tubular epithelial cells: evidence of polarity on both effector and target cells.
The mode by which cytolytic T-lymphocytes (CTL) deliver the lethal hit to their targets has been studied extensively. The CTL exhibits a characteristic polarization, with the attacking end formed by the uropod (containing the Golgi complex and associated granules). The effect on the target cell (TC) has been considered as a form of apoptosis or of both necrosis. In this communication we describe the particular morphological steps that relate to the participation of the target renal epithelial cell to its own destruction. Thus, the TC forms tight membrane contacts with the CTL that are invested by a dense network of stress fibers and microtubules within the TC cytoplasm in a manner similar to the areas of attachment between the epithelial cells or of the latter to the underlying surface. The TC mitochondria at the site of the CTL attachment are markedly swollen, in contrast to the more distally located ones that appear initially normal. The TC plasma membrane surrounding the CTL attachment site shows focally intense blebbing. In later stages, associated with overt apoptosis, global TC blebbing is present. In summary, the TC shows a polarization pattern, that corresponds roughly to the polarity exhibited by the attacking cell (uropod-protopod), and to some degree treats the latter cell as a junctional partner.
Papadimitriou
J C
JC
Department of Pathology, University of Maryland School of Medicine, Baltimore, USA.
Drachenberg
C B
CB
Hadley
G A
GA
Bartlett
S T
ST
Trump
B F
BF
D000818:Animals; D002450:Cell Communication; D016764:Cell Polarity; D002478:Cells, Cultured; D018920:Coculture Techniques; D004847:Epithelial Cells; D007684:Kidney Tubules / Q000166:cytology*; D051379:Mice; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D008854:Microscopy, Electron; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology*