DIFFERENTIAL-EFFECTS OF INTERLEUKIN-10 ON THE EXPRESSION OF HLA CLASS-II AND CD1 MOLECULES INDUCED BY GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR INTERLEUKIN-4
H. Thomssen et al., DIFFERENTIAL-EFFECTS OF INTERLEUKIN-10 ON THE EXPRESSION OF HLA CLASS-II AND CD1 MOLECULES INDUCED BY GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR INTERLEUKIN-4, European Journal of Immunology, 25(9), 1995, pp. 2465-2470
Interleukin (IL)-10 down-regulates HLA class II molecules, whether con
stitutively expressed or up-regulated by interferon-gamma or IL-4 on m
onocytes but not on B lymphocytes. In this study we show that IL-10 do
es not inhibit HLA class II expression induced by the combination gran
ulocyte/macrophage colony-stimulating factor and IL-4 on monocytes, al
though it simultaneously abrogates the expression of CD1 molecules ind
uced by the same combination of cytokines. CD1 molecules can act as el
ement of genetic restriction for CD4(-)CD8(-)T lymphocytes, and the su
ppression of CD1 expression by IL-10 abolished antigen presentation to
CD1-restricted CD4(-) CD8(-) T cell receptor-positive T cells. Althou
gh HLA class II expression was not down-regulated by IL-10, the antige
n specific proliferative response of CD4(+) T cells was nevertheless d
ecreased. This was not caused by down-regulation of known co-stimulato
ry molecules such as B7.1, B7.2 and ICAM-1. IL-10 decreased the antige
n specific proliferative response further by directly influencing the
T lymphocytes. Our results indicate that IL-10 exerts some of its immu
noregulatory functions by differential modulation of antigen presentin
g molecules, induced by the same combination of cytokines.