The disclosure features compounds comprising an antigen portion, a soluble Major Histocompatibility Complex (MHC) molecule portion (e.g., all or an antigen-binding portion of a soluble MHC class I molecule), and a dynamic anchor portion (e.g., an agent, such as Annexin V, that binds to phosphatidylserine). The featured compounds are useful for a variety of therapeutic applications, including, e.g., enhancing a T cell response to an antigen of interest or enhancing a T cell-driven immune response by a subject to an antigen of interest (e.g., a cancer antigen or a microbial antigen).