Streptococcus pyogenes cell envelope protease (SpyCEP)

Streptococcus pyogenes cell envelope protease (SpyCEP) is a large, multi-domain, cell wall-anchored subtilisin-like serine protease found in group A Streptococcus (GAS). It catalyzes the cleavage and inactivation of ELR+ CXC chemokines—most importantly interleukin-8 (CXCL8)—thereby impeding neutrophil recruitment and function at infection sites[1][2][7][9]. SpyCEP is considered a major virulence determinant, enabling immune evasion and contributing to severe GAS disease. Structurally, SpyCEP is unique, being autocatalytically processed into two non-covalently associated fragments, and is composed of nine domains essential for function and host interaction[1][4][9]. In addition to its proteolytic activity, SpyCEP can mediate uptake into endothelial cells, implicating roles beyond enzyme function[3]. Transcription of the spyCEP gene is tightly regulated, notably by the CovR/S system, which represses its expression under non-invasive conditions[2][5]. SpyCEP is under investigation both as a vaccine antigen and as a potential drug target for inhibitors that could restore effective host immune responses against GAS infection[4][7][9].

Other names

ScpCPrtScell envelope serine proteasegroup A Streptococcus (GAS) cell envelope protease

Inhibition of its protease activity would prevent chemokine degradation, enhancing neutrophil recruitment and bacterial clearance. Vaccination with inactivated SpyCEP can induce protective immunity in animal models[4].