Bacterial Plasminogen Receptors: Mediators of a Multifaceted Relationship

Figure 2

Mechanisms of bacterial cell surface plasmin(ogen) acquisition and its role in bacterial-host interactions. Plasmin(ogen) can be bound directly to the bacterial cell surface via cell-membrane-anchored receptors, nonanchored-cell-surface-associated receptors or indirectly through interactions with fibrinogen and cell surface fibrinogen receptors. Plasmin(ogen) localised on the bacterial cell surface is involved in four main processes; (1) ECM degradation via activated metalloproteases and plasmin; (2) fibrinolysis via plasmin; (3) immune evasion through plasmin-mediated degradation of immune effectors, including complement components and immunoglobulins; (4) adherence to host cells via plasminogen-linker interactions with host cell surface receptors. ECM: extracellular matrix; IgG: immunoglobulin G; RBC: red blood cell; SAK: staphylokinase; SEN: streptococcal α-enolase; Ska: streptokinase; tPA: tissue plasminogen activator; uPA; urokinase plasminogen activator.