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: Pathology
[{'content': 'Interleukin produced characteristically by TH1 \n(A)Interleukin 2\n(B)IL 5\n(C)IL γ\n(D)INF γ\n(E)IL 10 \nSelect and explain. \nA. AD, B. BD, C. CA, D. DE', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The following interleukin is characteristically produced in a TH1 response -\nExplanation:\nAns. is ‘a’ i.e., IL-2 [Ref: Robbins 7th/e p.\nA. T helper - 1 {TH\n1) secretes → IL-2 and interferon - γ\nB. T helper - 2 (T[f\n2) secretes → IL-4,IL-5, IL-6, EL-13\nT-cells\no T cells are amongst the two important cells of adaptive immune system (others are B-cells).\no T cell precursors arise in bone marrow (also in yolk sac & liver before birth) and migrate to the thymus,\no Maturity ofT-cells takes place in the thymus (So, T cells arise in bone marrow and mature in thymus),\no T-cells constitutes 60%-70% of the circulating peripheral lymphocytes.\no Based on their surface markers. target cells and functions the following T cell category have been identified:\n1. Helper/Inducer T cells\nThese cells have CD4 surface marker and are MHC class II restricted.\nThese are further subdivided into: -\nA. Effector CD4 helper T cells\no These cells secrete cytokines and other products that perform all major functions,\no These cells are of following types.\ni. TH, cells\nThese cells are activated by IFN-γ\nThese cells produce IL-2, IFNyand IL-12.\nThese cells facilitate delayed hypersensitivity, cell mediated immunity. Macrophage activation,\nKilling of intracellular microbes e.g., tuberculosis & leprosy.\nThese cells also induce destruction of target cell by : -\ni. Activating CD8 T cells to become cytotoxic cells; and\nii. Activating NK cells.\nii. TH, cells\nThese cells are activated by IL-4.\nThese cells secrete IL-4,1L-5, IL-6 and IL-13.\nthese cells facilitates the synthesis of antibodies particularly IgE and cause activation of mast\nCells and eosinophils → Therefore, provide defence against Helminthic parasites.\niii. TH17 cells\nA third subset of CD4 T-cells (besides TH1 and TH2) has been discovered recently and is\nCalled the\nTH17 cells.\nIf the antigen producing cells produce inflammatory cytokines such as IL-1, IL-6 and IL-23,\nThese work in collaboration with TGF-(3 to stimulate differentiation of T-cells to the TH 17\ncells.\nTH17 cells are powerful recruiters of neutrophils and monocytes, and thus play major roles in\nsevere inflammatoiy diseases.\nThey may also be important for defense against some bacterial and fungal infections in which\nneutrophilic inflammation is a prominent feature.\nTH 17 cells are activated by some microbial antigens and by self antigens in autoimmune\ndiseases. Activated TH17 cells secret IL-17, IL-22 and chemokines. Collectively, these\ncytokines recruit neutrophils and monocytes.\nTH17 cells produce IL-21, which amplifies the TH17 (self) response.\nB. Memory CD4 helper T cells\no Provide memory, i.e., retain the antigenic affinity of the originally activated T cells and are used to\nact aslater effector cells during a second immune response.\n2. Cytolytk/cytotoik T cells\nThese cells have CD8 surface marker and are MHC class I restricted.\nThey kill and lyse target cells including tumor cells, virus infected cells and allograft; and participate in\nType II Hypersensitivity.\n3. Suppressor T-cells\nThese cells have CDg surface marker and are MHC class I restricted.\nThese cells down regulate immune response.\no Helper T cell (CD4 T cell) is known as the master regulator of the immune system.\no The ratio of CD4 and CD8 T cell is normally 2 :1.', 'role': 'assistant'}]