Failure to detect IL-3-binding sites on human mast cells.
IL-3, a pleiotropic lymphokine, has been termed mast cell growth factor because it promotes growth and differentiation of murine mast cells. Murine mast cells, in turn, express cell surface receptors for IL-3. Human rIL-3 has been shown to induce proliferation and differentiation of human basophils and to activate basophils via high affinity binding sites. To investigate whether human mast cells express IL-3R, binding studies with 125I-radiolabeled human rIL-3 were performed on HMC-1, a novel human mast cell line, and on pure populations (i.e., 93 to 99% purity) of human tissue mast cells obtained with mAb and C from dispersed lung (n = 2). Unexpectedly, neither enriched human lung mast cells nor HMC-1 cells bound radiolabeled human rIL-3 specifically. Moreover, human rIL-3 failed to promote uptake of [3H]thymidine, synthesis of histamine, histamine releasability, or changes in expression of mast cell differentiation Ag (YB5B8, CD54/ICAM-1, CD9/p24, CD33/gp67) on either human lung mast cells or HMC-1 cells. It is hypothesized that the fundamental difference in the biologic response to IL-3 between human and murine mast cells is due to a loss during evolution of mast cell high affinity IL-3 binding sites.
Valent
P
P
I. Medical Department, University of Vienna, Austria.
Besemer
J
J
Sillaber
C
C
Butterfield
J H
JH
Eher
R
R
Majdic
O
O
Kishi
K
K
Klepetko
W
W
Eckersberger
F
F
Lechner
K
K
D015703:Antigens, CD / Q000032:analysis; D001491:Basophils / Q000187:drug effects / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D006801:Humans; D007377:Interleukin-3 / Q000378:metabolism* / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D016185:Receptors, Interleukin-3 / Q000032:analysis*; D011994:Recombinant Proteins / Q000494:pharmacology
D015703:Antigens, CD; D007377:Interleukin-3; D016185:Receptors, Interleukin-3; D011994:Recombinant Proteins