TY - JOUR
T1 - Down-modulation of CD4 antigen during programmed cell death in U937 cells
AU - Malorni, Walter
AU - Rivabene, Roberto
AU - Teresa Santini, Maria
AU - Paradisi, Silvia
AU - Iosi, Francesca
AU - Donelli, Gianfranco
PY - 1993/12/27
Y1 - 1993/12/27
N2 - It has been hypothesized that programmed cell death (PCD), an active cell suicide process occurring in place of necrosis, can be associated with the pathogenesis of acquired immunodeficiency syndrome (AIDS). The entry of human immunodeficiency virus (HIV) into competent cells is mediated by the CD4 molecule present on the surface of certain lymphocyte subpopulations as well as on some cultured cell lines, e.g. U937 myelomonocytic cells. The present paper focuses on some specific aspects of PCD induced by the cytokine tumor necrosis factor (TNF). The results obtained indicate that the exposure of U937 cells to cycloheximide facilitates TNF-mediated PCD via a short term cell death program and modifies the expression of CD4 surface molecules. This change in surface antigen expression, manifested by internalization of the CD4 molecule, occurs in cells in which apoptosis has been triggered, but not in cells undergoing necrosis. These results indicate that the progression of cell death could be associated with specific alterations of certain surface molecules and could have a role in the entry of HIV into cells.
AB - It has been hypothesized that programmed cell death (PCD), an active cell suicide process occurring in place of necrosis, can be associated with the pathogenesis of acquired immunodeficiency syndrome (AIDS). The entry of human immunodeficiency virus (HIV) into competent cells is mediated by the CD4 molecule present on the surface of certain lymphocyte subpopulations as well as on some cultured cell lines, e.g. U937 myelomonocytic cells. The present paper focuses on some specific aspects of PCD induced by the cytokine tumor necrosis factor (TNF). The results obtained indicate that the exposure of U937 cells to cycloheximide facilitates TNF-mediated PCD via a short term cell death program and modifies the expression of CD4 surface molecules. This change in surface antigen expression, manifested by internalization of the CD4 molecule, occurs in cells in which apoptosis has been triggered, but not in cells undergoing necrosis. These results indicate that the progression of cell death could be associated with specific alterations of certain surface molecules and could have a role in the entry of HIV into cells.
KW - Apoptosis
KW - CD4
KW - Down-modulation
UR - http://www.scopus.com/inward/record.url?scp=0027136181&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027136181&partnerID=8YFLogxK
U2 - 10.1016/0014-5793(93)80832-F
DO - 10.1016/0014-5793(93)80832-F
M3 - Article
C2 - 8262257
AN - SCOPUS:0027136181
VL - 336
SP - 335
EP - 339
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 2
ER -