Immune evasion

As immune evasion (of Latin evadere "escape, escape", English immune evasion or immune escape ) refers to a process by which pathogens using mutation or specific mechanisms of detection or defense by the immune system escape. The term is especially common in infectious diseases to summarize different mechanisms of endogenous (e.g. tumors and some prions ) or exogenous pathogens (e.g. viruses or bacteria ) to undermine the adaptive immune defense .

properties

The mechanisms that enable immune evasion are partly virulence factors . The immune evasion essentially extends to the following points of attack:

• Modification of the surfaces of antigens of the pathogen (by escape mutations arise escape mutants English escape mutants ), some endogenous under imitation epitopes ( molecular mimicry ). For viruses with a segmented genome and no replacement of, in addition segments ( English antigenic shift ) take place.
• Latency mechanisms for permanent retention within cells (see lysogenic cycle ).
• Downregulation of the synthesis of own antigens
• Destruction of immune cells or induction of anergy .
• Impairment of antigen presentation or previous antigen digestion in antigen presenting cells .
• Blocking of T-cell mediating cell lysis .
• Interaction with cytokines or their competitive inhibition by virokines .
• Avoidance of host cell apoptosis
• Infection of cell types that can only be destroyed to a limited extent in the course of an immune reaction (cells with immune privilege , e.g. keratinocytes , neurons or stem cells ).

literature

• S. Modrow, Dietrich Falke , U. Truyen: Molecular Virology . 2nd Edition. Spectrum, Heidelberg 2003, ISBN 3-8274-1086-X .
• DM Knipe, Peter M. Howley (Ed.): Fields Virology . 5th edition. Philadelphia 2007, ISBN 0-7817-6060-7 , Volume 1, pp. 316 ff.