Dr. Joel Ernst’s lab focuses on immunity to tuberculosis (TB) with the goal of informing the rational design and development of new TB vaccines. The group conducts basic studies on mechanisms of immunity and immune evasion in TB, using mouse models. In addition, the lab investigates human immunity to TB and has discovered that, unlike pathogens that use antigenic variation to evade immunity and establish persistent infection, the human T cell antigens and epitopes of Mycobacterium tuberculosis are highly conserved—even among strains that diverged from a common ancestor thousands of years ago. More recently, the team has identified rare M. tuberculosis antigens that show evidence of diversifying selection and has begun studies to test the hypothesis that T cell responses to these variable antigens are associated with superior protective immunity compared to responses targeting conserved antigens. Dr. Ernst’s work on human immunity to TB spans multiple continents and involves numerous collaborators at UCSF as well as partner institutions across the United States and internationally.