MICROANATOMY

Detailed explanation-1: -Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

Detailed explanation-2: -(HEL-per … sel) A type of immune cell that stimulates killer T cells, macrophages, and B cells to make immune responses. A helper T cell is a type of white blood cell and a type of lymphocyte. Also called CD4-positive T lymphocyte.

Detailed explanation-3: -Helper T cells become activated through a multistep process, which begins with antigen-presenting cells, such as macrophages. These cells ingest an infectious agent or foreign particle, partially degrade it, and export fragments of it-i.e., antigens-to the cell surface.