Immune System: Evolutionary Pressure of Infectious Agents

Masanori Kasahara, Hokkaido University Graduate School of Medicine, Sapporo, Japan

Published online: January 2011

DOI: 10.1002/9780470015902.a0001131.pub2

Abstract

Like all other biologic systems, the immune system emerged as a consequence of evolution. A major force that has driven the evolution of the immune system and shaped its current organisation was the needs to fight pathogens. Key elements of adaptive immunity, such as antigen receptors and major histocompatibility complex molecules, show evidence of selective pressures exerted by pathogens. Conversely, immune responses mounted by the host have also imposed strong selective pressures on pathogens. To escape immune attack from the host, pathogens have developed immune evasion tactics such as antigenic variation (as typically seen in influenza viruses) and the production of immune evasion proteins (as typically seen in herpesviruses). Mutation is the key genetic mechanism underlying the co‐evolution of the immune system and pathogens.

Key Concepts:

  • The immune system of vertebrates has evolved to fight pathogens.

  • Pathogens have exerted intense selective pressures on the evolution of the immune system.

  • Key elements of the adaptive immune system, such as antigen receptors and major histocompatibility complex molecules, show evidence of such selective pressures.

  • Immune responses by the host exert strong selective pressures on pathogens.

  • To escape immune attack, pathogens change their antigenicity or produce immune evasion proteins.

  • Mutation is the key genetic mechanism underlying the co‐evolution of the immune system and pathogens.

Keywords: immunity; T cells; antibody; MHC; mutation; pathogen; virus

Figure 1.

The defence systems of animals. IL‐1, interleukin 1; IL‐6, interleukin 6 and TNFα, tumour necrosis factor α.
Figure 2.

Schematic representation of the mammalian immunoglobulin G molecule. Fab, antigen‐binding fragment; F(ab′)2, divalent antigen‐binding fragment; Fc, crystallisable fragment; VH, heavy chain variable domain; CH, heavy chain constant domain; VL, light chain variable domain and CL, light chain constant domain.

Figure 3.

Schematic representation of antigen recognition by T cells. The T‐cell receptor (TCR) recognises a peptide antigen bound to a major histocompatibility complex (MHC) class I (a) or class II (b) molecule expressed by an antigen‐presenting cell (APC). Successful recognition of antigen by a T cell also involves interactions between additional pairs of molecules expressed on T cells and APCs: leucocyte functional antigen (LFA)1–intercellular adhesion molecule (ICAM)1, cluster of differentiation (CD) 2–LFA‐3, CD28–B7‐1/B7‐2 and CD8–MHC I or CD4–MHC II. The peptides of the CD3 complex are involved in signalling T‐cell activation: following recognition of an MHC–peptide complex by the TCR, CD3 transduces signals across the plasma membrane to initiate activation of the T cell. Several of the other molecules also participate in this signal transfer.

Figure 4.

Schematic representation of the pathway by which extracellular protein antigens are taken up by antigen‐processing cells, processed, and then expressed in association with major histocompatibility complex (MHC) class II molecules. HLA, human leucocyte antigen and CLIP, class II‐associated invariant chain peptide.

Figure 5.

Schematic representation of the pathway by which internal protein antigens are processed and expressed in association with major histocompatibility (MHC) class I molecules. TAP, transporter associated with antigen processing.

close

References

Ackerman AL and Cresswell P (2004) Cellular mechanisms governing cross‐presentation of exogenous antigens. Nature Immunology 5: 678–684.

Ades S, Koushik A, Duarte‐Franco E et al. (2008) Selected class I and class II HLA alleles and haplotypes and risk of high‐grade cervical intraepithelial neoplasia. International Journal of Cancer 122: 2820–2826.

Allison AC (2009) Genetic control of resistance to human malaria. Current Opinion in Immunology 21: 499–505.

Beck S and Trowsdale J (2001) The human major histocompatibility complex: lessons from the DNA sequence. Annual Reviews of Genomics and Human Genetics 1: 117–137.

Bjorkman PL (1997) MHC restriction in three dimensions: a view of T cell receptor/ligand interactions. Cell 89: 167–170.

Briles WE, Stone HA and Cole RK (1977) Marek's disease: effects of B histocompatibility alloalleles in resistant and susceptible chicken lines. Science 195: 193–195.

Bryant PW, Lennon‐Duménil AM, Fiebiger E et al. (2002) Proteolysis and antigen presentation by MHC class II molecules. Advances in Immunology 80: 71–114.

Carrington M, Nelson GW, Martin MP et al. (1999) HLA and HIV‐1: heterozygote advantage and B*35‐Cw*04 disadvantage. Science 283: 1748–1752.

Cooke GS and Hill AV (2001) Genetics of susceptibility to human infectious disease. Nature Reviews Genetics 2: 967–977.

Doherty PC and Zinkernagel RM (1975) A biological role for the major histocompatibility antigens. Lancet 1: 1406–1409.

Flajnik MF and Du Pasquier L (2008) Evolution of the immune system. In Paul WE (ed.) Fundamental Immunology, pp. 56–124. Philadelphia: Lippincott Williams & Wilkins.

Gao X, Nelson GW, Karacki P et al. (2001) Effect of a single amino acid change in MHC class I molecules on the rate of progression to AIDS. New England Journal of Medicine 344: 1668–1675.

Garcia KC and Adams EJ (2005) How the T cell receptor sees antigen – a structural view. Cell 122: 333–336.

Hansen TH and Bouvier M (2009) MHC class I antigen presentation: learning from viral evasion strategies. Nature Reviews Immunology 9: 503–513.

Hill AV, Jepson A, Plebanski M et al. (1997) Genetic analysis of host–parasite co‐evolution in human malaria. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 352: 1317–1325.

Hill AVS, Allsopp CEM, Kwiatowski D et al. (1991) Common West African HLA antigens are associated with protection from severe malaria. Nature 352: 595–600.

Horimoto T and Kawaoka Y (2005) Influenza: lessons from past pandemics, warnings from current incidents. Nature Reviews Microbiology 3: 591–600.

Horton R, Wilming L, Rand V et al. (2004) Gene map of the extended human MHC. Nature Reviews Genetics 5: 889–899.

Itescu S, Mathur‐Wagh U, Skovron ML et al. (1992) HLA‐B35 is associated with accelerated progression to AIDS. Journal of Acquired Immune Deficiency Syndromes 5: 37–45.

Kaslow RA, Carrington M, Apple R et al. (1996) Influence of combinations of human major histocompatibility complex genes on the course of HIV‐1 infection. Nature Medicine 2: 405–411.

Kaufmann SHE, Sher A and Ahmed R (eds) (2002) Immunology of Infectious Diseases. Washington, DC: ASM Press.

Kumánovics A, Takada T and Lindahl KF (2003) Genomic organization of the mammalian MHC. Annual Reviews of Immunology 21: 629–657.

Lawlor DA, Zemmour J, Ennis PD et al. (1990) Evolution of class‐I MHC genes and proteins: from natural selection to thymic selection. Annual Reviews of Immunology 8: 23–63.

Litman GW, Cannon JP and Dishaw LJ (2005) Reconstructing immune phylogeny: new perspectives. Nature Reviews Immunology 5: 866–879.

Martin MP and Carrington M (2005) Immunogenetics of viral infections. Current Opinion in Immunology 17: 510–516.

McKiernan SM, Hagan R, Curry M et al. (2004) Distinct MHC class I and II alleles are associated with hepatitis C viral clearance, originating from a single source. Hepatology 40: 108–114.

Parham P, Adams EJ and Arnett KL (1995) The origins of HLA‐A,B,C polymorphism. Immunological Reviews 143: 141–180.

Potts WK and Slev PR (1995) Pathogen‐based models favouring MHC genetic diversity. Immunological Reviews 143: 181–197.

Rammensee HG (1995) Chemistry of peptides associated with MHC class I and class II molecules. Current Opinion in Immunology 7: 85–96.

Rock KL, York IA, Saric T et al. (2002) Protein degradation and the generation of MHC class I‐presented peptides. Advances in Immunology 80: 1–70.

Starr TK, Jameson SC and Hogquist KA (2003) Positive and negative selection of T cells. Annual Reviews of Immunology 21: 139–176.

Tanaka K and Kasahara M (1998) The MHC class I ligand‐generating system: roles of immunoproteasomes and the interferon‐γ‐inducible proteasome activator PA28. Immunological Reviews 163: 161–176.

Tang J, Costello C, Keet IP et al. (1999) HLA class I homozygosity accelerates disease progression in human immunodeficiency virus type 1 infection. AIDS Research and Human Retroviruses 15: 317–324.

Thio CL, Thomas DL, Karacki P et al. (2003) Comprehensive analysis of class I and class II HLA antigens and chronic hepatitis B virus infection. Journal of Virology 77: 12083–12087.

Tonegawa S (1983) Somatic generation of antibody diversity. Nature 302: 575–581.

Trowsdale J and Parham P (2004) Defense strategies and immunity‐related genes. European Journal of Immunology 34: 7–17.

Zinkernagel RM and Doherty PC (1997) The discovery of MHC restriction. Immunology Today 18: 14–17.

Further Reading

Alcaïs A, Abel L and Casanova JL (2009) Human genetics of infectious diseases: between proof of principle and paradigm. Journal of Clinical Investigation 119: 2506–2514.

Ewald PW (1994) Evolution of Infectious Disease. Oxford: Oxford University Press.

Flajnik MF and Kasahara M (2010) Origin and evolution of the adaptive immune system: genetic events and selective pressures. Nature Reviews Genetics 11: 47–59.

Hill AV (2006) Aspects of genetic susceptibility to human infectious diseases. Annual Reviews of Genetics 40: 469–486.

Kasahara M (ed.) (2000) Major Histocompatibility Complex: Evolution, Structure, and Function. Tokyo: Springer.

Klein J (1986) Natural History of the Major Histocompatibility Complex. New York: Wiley.

Klein J, Satta Y, O'hUigin C et al. (1993) The molecular descent of the major histocompatibility complex. Annual Reviews of Immunology 11: 269–295.

Related Sub-Topics:

Adaptive Evolution | Infection | Acquired (Adaptive) Immunity | Selection and Variation | Coevolution
Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

Article Title: Immune System: Evolutionary Pressure of Infectious Agents
 
How to Cite close
Kasahara, Masanori(Jan 2011) Immune System: Evolutionary Pressure of Infectious Agents. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001131.pub2]