We examined chemotaxis of human plasma cells (PCs) in response to extr
acellular matrix proteins (ECMs) in the human PC cell lines FR4ds and
OPM-1ds. The FR4ds cells expressed beta 1(+), beta 3(-), alpha 2(-), a
lpha 3(-), alpha 4(+), alpha 5(+), alpha 6(+), and alpha v(+) integrin
s, whereas the OPM-1ds cells expressed beta 1(+), beta 3(-), alpha 2(-
), alpha 3(+), alpha 4(+), alpha 5(-), alpha 6(+), and alpha v(+). Fib
ronectin (FN) and laminin (LN) promoted the chemotaxis of the PCs. An
inhibitory assay with anti-integrin monoclonal antibodies (MoAbs) show
ed that anti-alpha 4 MoAb partially inhibited the chemotaxis of FR4ds
and completely inhibited the chemotaxis of OPM-1ds. Anti-alpha 5 MoAb
alone had no effect on either of these two lines. Nevertheless, anti-a
lpha 5 MoAb completely inhibited chemotaxis when it was added with ant
i-alpha 4 in FR4ds, demonstrating a novel complementary role of VLA-5
toward VLA-4 in the chemotaxis induced by FN. LN facilitated chemotaxi
s both in OPM-1ds expressing alpha 3 and alpha 6 integrins and in FR4d
s expressing alpha 6 integrin alone. Anti-alpha 6 MoAb completely inhi
bited FR4ds chemotaxis, whereas anti-alpha 3 and -alpha 6 MoAb had syn
ergistic inhibitory effects on the chemotaxis of OPM-1ds. These result
s indicated that the distribution of PCs in human tissue are determine
d by at least two factors: the concentration of the ECM proteins FN an
d LN and the expression of integrins. (C) 1995 by The American Society
of Hematology.