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What is CD4 count refers to - and explain in detail?
Ans. is 'a' i.e., T helper cells o Helper T-cells - CD4 positive.o Cytotoxic T-cells and suppressor T-cells - CD 8 positive,o Based on function CD4 helper T cells are divided into-1. Effector CP4 helper Tcells# Functions are :-A. By TH1 cellsActivate macrophagesDelayed hypersensitivityCell mediated immunityKilling of intracellular microbes.e.g. tuberculosis and leprosyDestruction of target cells by-Activate CDS T cells to become cytotoxic cells.Activate NK cellsB By TH2 celtsi) Activate B cells to develop into antibody producing plasma cells - facilitate 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.