Immunological Tolerance
Immunological Tolerance
Immunological Tolerance
Immunological Tolerance
Dr. Barasa
18022020
Learning Objectives
By the end of this lecture the learner should be able to:
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Immunological Tolerance
• A state of unresponsiveness that is specific for a
particular antigen
• Induced by prior exposure to that antigen
E.g. to food antigens, air-borne antigens
• Tolerogens: antigens that induce tolerance
Self Tolerance
• Prevents the body from mounting an immune attack
against its own tissues
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Route of administration
• SQ or IM favour an immune response
• Oral (& at times IV) route favours tolerance
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Central tolerance
Established in lymphocytes developing in central
lymphoid organs
Peripheral tolerance
Acquired by mature lymphocytes in the peripheral tissues
(after leaving the primary lymphoid organs)
Clonal deletion
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• Inducing anergy
• Preventing migration into B cell follicles
• Cell death
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