CD4 count refers to

Helper T-cells → CD4 positive. o Cytotoxic T-cells and suppressor T-cells → CD 8 positive, Based on function CD4 helper T cells are divided into1. Effector CP4 helper T-cells Functions are- A. By TH1 cells i. Activate macrophages ii. Delayed hypersensitivity iii. Cell-mediated immunity iv. The killing of intracellular microbes. e.g. tuberculosis and leprosy v. Destruction of target cells by. Activate CDS T cells to become cytotoxic cells. b. Activate NK cells B By TH2 celts i) Activate B cells to develop into anybody producing plasma cells → facilitate the synthesis of antibodies. 2. Memory CD4 helper T cells □ Retain the antigenic affinity of the originally activated T cells and are used to act as later effector cells during a second immune response.