Development of anti-matrix metalloproteinase-2 (MMP-2) nanobodies as potential therapeutic and diagnostic tools.

Matrix metalloproteinase-2 (MMP-2) is an endopeptidase involved in cardiovascular disease and cancer. To date, no highly selective MMP-2 inhibitors have been identified for potential use in humans. Aim of our work was to apply the nanobody technology to the generation of highly selective inhibitors of human MMP-2 and to assess their effects on platelet function and their applicability as conjugated nanobodies. We constructed a nanobody library after immunising an alpaca with human active MMP-2 and identified, after phage display and screening, one MMP-2 inhibitory nanobody (VHH-29), able to hinder the effects of MMP-2 on platelet activation, and one nanobody not inhibiting MMP-2 activity (VHH-136) which, chemically conjugated to a fluorescent probe, allowed the detection of human MMP-2 by flow-cytometry and immune-cytochemistry. In conclusion, we have generated and characterized two new nanotechnological molecular tools for human MMP-2 which represent promising agents for the study of MMP-2 in cardiovascular pathophysiology.