Abstract: Improved anti-CD154 antibodies are provided herein which have improved therapeutic potency, in vivo half-life and ablated FcR binding and/or complement binding/activation. The use of these antibodies for inducing tolerance and treating immune diseases including autoimmunity, inflammation, transplant recipients, fibrosis and allergic disorders is disclosed herein.

Abstract: The present invention is directed to the use of VISTA agonists alone or in association with other immune inhibitors, preferably another inhibitor of humoral immunity such as an iNOS/NO promoter or nitric oxide or a PD-1 or PD-L1 agonist or a CD40 antagonist for the treatment or prevention of conditions wherein the suppression of humoral immunity is therapeutically beneficial. The present invention is further directed to the use of VISTA antagonists alone or in association with other immune agonists, preferably another enhancer of humoral immunity such as iNOS/NO inhibitor or a PD-1 or PD-L1 antagonist or anti-CTLA-4 antibody or a CD40 agonist for the treatment or prevention of conditions wherein the enhancement of humoral immunity is therapeutically beneficial. Also, the invention relates to the use of VISTA antagonists alone or in association with another immune agonist, e.g., an iNOS/NO inhibitor or a CD40 agonist to promote the efficacy of therapeutic and prophylactic vaccines, e.g.