Y. Arinobu et al., Antagonistic effects of an alternative splice variant of human IL-4, lL-4 delta 2, on IL-4 activities in human monocytes and B cells, CELL IMMUN, 191(2), 1999, pp. 161-167
IL-4 is a pleiotropic cytokine which exerts its actions on various lineages
of hematopoietic and nonhematopoietic cells. This cytokine is one of the c
entral regulators of immunity in health and disease states. An alternative
splice variant, in which the second of four exons is omitted, has been rece
ntly described and designated as IL-4 delta 2. The variant has been previou
sly described as a potential naturally occurring antagonist of human IL-4 (
hIL-4)-stimulated T cell proliferation. In this study, we investigated the
effects of recombinant human (rh) IL-4 delta 2 on monocytes and B cells. In
monocytes, rhIL-4 delta 2 blocked inhibitory action of hIL-4 on LPS-induce
d cyclooxygenase-2 expression and subsequent prostaglandin E-2 secretion. I
n B cells, rhIL-4 delta 2 was an antagonist of the hIL-4-induced synthesis
of IgE and expression of CD23. Our results broaden the spectrum of hIL-4-an
tagonistic activities of rhIL-4 delta 2, thus creating the background for t
he potential use of rhIL-4 delta 2 as a therapeutic anti-hIL-4 agent. (C) 1
999 Academic Press.