ABSTRACT
The IgA1 proteases are a group of proteolytic enzymes, which are produced by pathogenic bacteria that infect and colonize mucosal surfaces. This group of proteolytic enzymes was found to cleave specific peptide bonds within the sequence TPPTPSPSTPPTPSPS (T, P and S are threonine, proline and serine residues, respectively) found in the hinge region of human IgA1. Several findings support the role of IgA1 protease, for example, its ability to cleave human LAMP1 (hLAMP1), TNF-RII, the CD8 molecule of T lymphocytes and granulocyte-macrophage colony-stimulating factor (GM-CSF), synaptobrevin II, hormone human chorionic gonadotropin, and its ability to exhibit important immunomodulatory properties, etc. , in particular the induction of proinflammatory cytokines. The IgA1 proteases have been found to instigate part of the T cell inflammatory response, especially to stimulate the release of cytokines such as tumour necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-8 (IL-8). All these suggest that this enzyme plays a significant role in pathogenesis. There are many other researches to explore new biological treatments of diseases using the biological characteristics of IgA1 protease.