Expression and role of p75 interleukin 2 receptor on human monocytes.
We investigated the expression of IL-2R subunits in human monocytes using the TU27 mAb, which recognizes the p75 chain, and anti-Tac mAb, which recognizes the p55 moiety of the IL-2R. We found that p75 but not p55 is constitutively expressed in more than 90% of fresh human monocytes. Antibody to p75, but not to p55, inhibited the activation of monocytes to a cytotoxic stage induced by IL-2 but did not block IFN-gamma-induced cytotoxicity. Our data demonstrate that the p75 chain is expressed on human monocytes and is involved in the activation of monocytes by IL-2.
Espinoza-Delgado
I
I
Biological Response Modifiers Program, National Cancer Institute, Frederick, Maryland 21701.
Ortaldo
J R
JR
Winkler-Pickett
R
R
Sugamura
K
K
Varesio
L
L
Longo
D L
DL
D000911:Antibodies, Monoclonal; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000302:isolation & purification
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D046911:Macromolecular Substances; D015375:Receptors, Interleukin-2; D007371:Interferon-gamma