Explore the intricate world of lymphocyte activation with Dr. Marc Jenkins, focusing on CD4+ T and B cell activation. Topics cover metabolic control of T follicular helper cells, the impact of HIV treatment on microbiome, rare side effects of COVID-19 vaccines, the role of CD28 activation in T cell response, and the challenges in studying CD4 T cells. Dr. Jenkins also shares insights into TCR signaling, T cell differentiation, and his outdoor adventures in fishing and biking.