Helper t cells do what?

Help activate cells: Helper T cells are essential regulators of adaptive immune responses and inflammatory diseases. They represent a sub-group of lymphocytes, that play an important role in maximizing the immune system. While these cells have little or no cytolytic or phagocytic activity, they are involved in activating and directing other immune cells such as B cells and macrophages.

Manage immunity: Helper T cells are unit commanders that instruct soldiers on the front lines. They help B cells secrete protective antibodies. They help "killer" T cells attack infected cells. They also influence the "flavor" of the immune response to favor more of an allergic-type response versus more of a flu-like response. They are CD4 positive cells that are destroyed in HIV/AIDS leading to immunodeficiency.