Abstract: The duration of antibody responses varies widely with the specific vaccine or infection. The specific features of the immunogen and host responses that are responsible for these differences remain poorly understood. In this application, we describe two transcription factors of the BTB/POZ family which exert opposing effects on the duration of antibody production. The first of these factors, Zbtb20, promotes plasma cell survival and is required for primary long-term antibody responses when aluminum salts, but not Toll-like receptor ligands are used as the adjuvant. The second factor, Zbtb32, promotes plasma cell death and limits the duration of antibody production following memory B cell recall responses, but not primary antibody responses. Based on these findings, we propose to establish the cellular events that explain how adjuvants influence the duration of immunity, and to uncover the physiological consequences to the diversity of antibody responses when recall responses persist for too long. Moreover, we propose to identify the molecular mechanisms of how Zbtb20 and Zbtb32 function to control the duration of humoral immunity.