This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'All of the following are functions of CD4 helper cells, except - \nSelect and explain. \nA. Immunogenic memory, B. Produce immunoglobulins, C. Activate macrophages, D. Activate cytotoxic cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Based on the secretion of different cytokines CD4 Helper T cells are divided into TH1 and TH2.\nBased on function CD4 helper T cells are divided into-\n\n1) Effector CD4 helper T-cells \n- These cells secrete cytokines and other products that perform all major functions.\n- These include TH1 and TH2 helper cells.\n- Functions are-\nA) By TH1 cells\n\nActivate macrophages\nDelayed hypersensitivity\nCell-mediated immunity\nThe killing of intracellular microbes. e.g. tuberculosis and leprosy\nDestruction of target cells by-\n\n\nActivate CD8 T cells to become cytotoxic cells.\nActivate NK cells\n\nB) By TH2 cells\ni)\xa0\xa0\xa0 Activate B cells to develop into antibody-producing plasma cells → facilitate the synthesis of antibodies.\n2) Memory CD4 helper T cells \n\nRetain the antigenic affinity of the originally activated T cells and are used to act as later effector cells during a second immune response.', 'role': 'assistant'}]