FIG. 1.
Design of soluble CD40L constructs. pTr-CD40L is a 1-trimer protein consisting of an isoleucine zipper (boxed area with thick gray lines) followed by the CD40L extracellular domain (ECD) (▪), similar to the sCD40LT protein used in many studies (63). pAcrp30-CD40L is a 2-trimer protein produced as a fusion between the body of Acrp30 (boxed area with thin gray lines) and the CD40L ECD (▪). pSP-D-CD40L is a 4-trimer protein produced as a fusion between the body of surfactant protein D (□) and the CD40L ECD (▪).