Reducing systemic regulatory T cell levels or activity for treatment of amyotrophic lateral sclerosis

A method of treating an Amyotrophic Lateral Sclerosis, the method comprising administering to an individual in need thereof a composition comprising an anti-programmed death ligand 1 (PD-L1) antibody, the anti-PD-L1 antibody including a human neutralizing PD-L1 antibody or a humanized neutralizing anti-PD-L1 antibody, or an anti-PD-L1 antibody fragment thereof having antagonistic or inactivating activity,

• wherein the composition is administered by a dosage regime comprising at least two courses of therapy, each course of therapy comprising in sequence a treatment session where the composition is administered to the individual followed by a non-treatment period where the composition is not administered to the individual,
• wherein the non-treatment period is longer than the treatment session;
• wherein, if administration of the composition during the treatment session is a repeated administration, the non-treatment period is longer than the period between repeated administrations during the treatment session;
• and
• wherein administration of the composition transiently reduces levels of systemic immunosuppression and increases choroid plexus gateway activity in facilitating selective recruitment of immune cells into the central nervous system, thereby treating the individual.