The present specification discloses modified anti-PD-L1 antibodies that abolishes Fc-related effector function and enhances clearance rate while maintaining therapeutic efficacy for neurodegenerative disease modification. The present specification also discloses nucleic acid sequences and expression constructs encoding such modified anti-PD-L1 antibodies as well as methods of making such modified anti-PD-L1 antibodies. In addition, the present specification discloses methods of treatment and uses that employ an administration regime of the disclosed anti-PD-L1 antibodies that ensures the antibodies are present for only a specific period of time and then are sufficiently cleared from the body to ensure treatment efficacy is maintained.