The IL-2 receptor present on human embryonic fibroblasts is functional in the absence of P64/IL-2R gamma chain.
In this study, we have investigated the IL-2R gamma gene expression in several human embryonic fibroblasts which express other components of the IL-2 receptor (IL-2R). Polymerase chain reaction did not allow us to detect IL-2R gamma transcripts in these cells but the functionality of the IL-2R alpha beta was not affected. Indeed, in the human IL-2R alpha+beta+gamma- embryonic lung fibroblasts ICIG-7, IL-2 induced identical phenomena to those previously reported in lymphoid cells: rapid internalization of the IL-2R alpha beta-IL-2 complex, specific phosphorylation of cellular proteins (56 and 38 kDa) and up-regulation of ICAM-1 expression. IL-2 induction of ICAM-1 was only observed in sparse cultures and for IL-2 concentrations over 180 pM. We have also observed, in these fibroblastic cells, the up-regulation of ICAM-2 expression by IL-2, both in sparse and dense cultures. These data show that p64/IL-2R gamma expression in human embryonic fibroblasts does not correlate with the ability of the IL-2R to deliver a biological signal.
Plaisance
S
S
Unité INSERM-268, Oncogenèse Appliquée, Hôpital Paul Brousse, Villejuif, France.
Rubinstein
E
E
Alileche
A
A
Benoit
P
P
Jasmin
C
C
Azzarone
B
B
D000595:Amino Acid Sequence; D015703:Antigens, CD; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000032:analysis; D002460:Cell Line; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000737:chemistry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D007376:Interleukin-2 / Q000494:pharmacology; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D015703:Antigens, CD; D015815:Cell Adhesion Molecules; C065289:ICAM2 protein, human; D007376:Interleukin-2; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D018799:Intercellular Adhesion Molecule-1