IMMUNOLOGY

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: -Helper T-cells are a type of immune cell. When they sense an infection, they activate other immune cells to fight it. They may activate cytotoxic T-cells or they may activate B-cells, which produce antibodies.

Detailed explanation-3: -Adaptive Immune Responses to Infection Activated T helper cells also secrete cytokines that lead to activation of other T helper cells as well as activating Tc and B lymphocytes. The result is a population of lymphocytes cytotoxic for infected cells and antibody production.

Detailed explanation-4: -Helper-T-cell activation Helper T cells do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies.

Detailed explanation-5: -Types of T-cells Helper T-cells stimulate B-cells to make antibodies and help killer cells develop. Killer T-cells or cytotoxic T-cells directly kill cells that have already been infected by a foreign invader.