Technique to detect tissue fibrogenesis using the antibodies against TGF-β LAP degradation products
The most fibrogenic cytokine, TGF-β, is produced as a latent complex, in which active TGF-β is wrapped by latency associated protein (LAP), preventing TGF-β from binding its receptor on target cells. Therefore, active TGF-β must be released from latent complexto exert biological activities (TGF-β activation reaction). We elucidated that plasma kallikrein cleaves LAP between R58 and L59 residues and activates TGF-β in the pathogenesis of liver fibrosis. To detect degradated products of LAP (LAP-DPs), we produced two specific antibodies. One is the R58 antibody detecting N-terminal side LAP-DPs terminating on R58 residue (R58 LAP-DPs), and another is L59 antibody detecting C-terminal side LAP-DPs starting from L59 residue (L59 LAP-DPs). We established techniques to detect each LAP-DPs using the antibodies. The R58 LAP-DPs remaining in tissues or cell surfaces through S-S bonded LTBP can be detected by immunostaining with the R58 antibody, whereas the L59 LAP-DPs released into blood can be measured by the ELISA using the L59 antibody. These LAP-DPs can be a surrogate biomarker of TGF-ß activation and subsequent fibrogenesis.
- LAP degradation product reflects plasma kallikrein-dependent TGF-β activation in patients with hepatic fibrosis, Hara M., Kirita A., Kondo W. et al. Springerplus. May 1; 3: 221. PMID: 24877031 (2014)