Mj. Burns et Mb. Furie, BORRELIA-BURGDORFERI AND INTERLEUKIN-1 PROMOTE THE TRANSENDOTHELIAL MIGRATION OF MONOCYTES IN-VITRO BY DIFFERENT MECHANISMS, Infection and immunity, 66(10), 1998, pp. 4875-4883
A prominent feature of Lyme disease is the perivascular accumulation o
f mononuclear leukocytes, Incubation of human umbilical vein endotheli
al cells (HUVEC) cultured on amniotic tissue with either interleukin-l
(IL-1) or Borrelia burgdorferi, the spirochetal agent of Lyme disease
, increased the rate at which human monocytes migrated across the endo
thelial monolayers. Very late antigen 4 (VLA-4) and CD11/CD18 integrin
s mediated migration of monocytes across HUVEC exposed to either B. bu
rgdorferi or IL-1 in similar manners. Neutralizing antibodies to the c
hemokine monocyte chemoattractant protein 1 (MCP-1) inhibited the migr
ation of monocytes across unstimulated, IL-l-treated, or B. burgdorfer
i-stimulated HUVEC by 91% +/- 3%, 65% +/- 2%, or 25% +/- 22%, respecti
vely. Stimulation of HUVEC with B. burgdorferi also promoted a 6 fold
+/- 2-fold increase in the migration of human CD4(+) T lymphocytes. Al
though MCP-1 played only a limited role in the migration of monocytes
across B, burgdorferi-treated HUVEC, migration of CD4(+) T lymphocytes
across HUVEC exposed to spirochetes was highly dependent on this chem
okine, The anti-inflammatory cytokine IL-10 reduced both migration of
monocytes and endothelial production of MCP-1 in response to B. burgdo
rferi by approximately 50%, yet IL-10 inhibited neither migration nor
secretion of MCP-1 when HUVEC were stimulated with IL-1. Our results s
uggest that activation of endothelium by B. burgdorferi may contribute
to formation of the chronic inflammatory infiltrates associated with
Lyme disease. The transendothelial migration of monocytes that is indu
ced by B, burgdorferi is significantly less dependent on MCP-1 than is
migration induced by IL 1. Selective inhibition by IL-IO further indi
cates that B. burgdorferi and IL 1 employ distinct mechanisms to activ
ate endothelial cells.