Final answer:
CD4+ T cells recognize MHC Class II peptides on antigen-presenting cells such as macrophages, dendritic cells, and B cells. The CD4 molecule on the surface of the T cell binds to the MHC Class II molecule, allowing the T cell to interact with the antigen-presenting cell and initiate an immune response.
Step-by-step explanation:
CD4+ T cells recognize MHC Class II peptides.
T cells are a type of white blood cell that play a crucial role in the immune response. CD4+ T cells, also known as helper T cells, recognize antigens presented in association with MHC Class II molecules. These MHC Class II molecules are found on antigen-presenting cells such as macrophages, dendritic cells, and B cells. The CD4 molecule on the surface of the helper T cell binds to the MHC Class II molecule, allowing the T cell to interact with the antigen-presenting cell and initiate an immune response.