For Vd=5V, Vg=0V,Vs=0V,Vb=-15V,Vth=0.7V(for average NMOS transistor )
So Vgs=Vg-Vs=0-0=OV < Vth=0.7V, the transistor is cut off.
Another problem, Vsb= Vs-Vb=0-(-15)=15V, the voltage difference of Sourec and Bulk must cause body effect which will impact performances of your desgin.