All bonds issued pursuant to this Act shall be obligations of the Board payable only in accordance with the terms thereof and shall not be obligations general, special or otherwise, of the State of Illinois. Such bonds shall not constitute a debt, legal or moral, of the State of Illinois, and shall not be enforceable against the State, nor shall payment thereof be enforceable out of any funds of the Board, or of any University, other than the income and revenues pledged and assigned to, or in trust for the benefit of, the holder or holders of such bonds.