Lecture
This lecture covers the differentiation of CD4+ T cells into Th1 and Th2 subgroups, which respond differently to various pathogens. Th1 cells secrete IFN-y to defend against intracellular microbes, while Th2 cells produce IL-4 and IL-5 to combat helminths and trigger allergic reactions. The lecture also discusses the characteristics and functions of macrophages, the activation of immune responses by different cytokines, and the role of transcription factors in T cell differentiation. The polarization towards Th1 or Th2 is influenced by the cytokine microenvironment and the nature of the antigen presented, involving different signaling pathways and transcription factors.