Definition of a specific interaction between the early T lymphocyte activation 1 (Eta-1) protein and murine macrophages in vitro and its effect upon macrophages in vivo.
The Eta-1 gene specifies a secreted product of activated T cells and is associated with genetic resistance to infection by an obligate intracellular bacterium. Previous studies have suggested that eta-1 might affect the ability of macrophages to migrate to the site of bacterial infection and/or to inhibit intracellular bacterial growth. We therefore examined the interaction of eta-1 with macrophages in vitro and in vivo. We find that macrophages express approximately 10(4) eta-1 receptors/cell and each receptor has a Kd of approximately 5 x 10(-10) M. The subsequence of eta-1 containing an RGD motif is required for binding because a synthetic peptide containing the eta-1 RGD domain inhibited protein attachment to macrophages. We also found that subcutaneous inoculation of mice with eta-1 resulted in a cellular infiltrate comprised primarily of macrophages. We propose that the interaction between eta-1 and its receptor on macrophages results in a change in macrophage physiology resulting in accumulation of these cells at extravascular sites.
Singh
R P
RP
Dana Farber Cancer Institute, Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115.
Patarca
R
R
Schwartz
J
J
Singh
P
P
Cantor
H
H
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000008:administration & dosage / Q000276:immunology* / Q000302:isolation & purification; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D015870:Gene Expression; D066298:In Vitro Techniques; D007249:Inflammation / Q000276:immunology; D037181:Lectins, C-Type; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000276:immunology; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D037181:Lectins, C-Type; D009842:Oligopeptides; D000099192:CD69 Antigens; C047981:arginyl-glycyl-aspartic acid