Antigenic Variation in Microbial Evasion of Immune Responses

Girish J Kotwal, LLC, Louisville, Kentucky, USA
Amod P Kulkarni, University of Cape Town, Cape Town, South Africa

Published online: December 2007

DOI: 10.1002/9780470015902.a0001207.pub2

Antigenic variation is the means by which certain pathogenic microorganisms evade immune surveillance. Through a variety of mechanisms, the antigenicity of their surface proteins is varied, thereby preventing the host organism from mounting an effective immune response. This has serious public health consequences, e.g. the current human immunodeficiency virus pandemic and the looming influenza pandemic.

Keywords: mutation; antigenic drift and shift; species jumping; pandemic; gene switching; gene duplication

Figure 1. Surface variation in trypanosomes. (a) Mechanism of transposition of trypanosomes in developing a large repertoire of VSGs. (b) Levels of antibody response following trypanosome infection. The level of antibody peaks after surface expression of the corresponding VSG has ceased.
Figure 2. Proposed model for the broad-spectrum neutralizing, prophylactic and preventive oral vaccine against retroviruses (HIV and influenza). HIV and influenza (and their subtypes) surface glycoproteins play an important role in the pathogenesis mediated by these viruses. Owing to constant mutations in the cell surface glycoproteins, neutralizing antibodies targeting one glycoprotein may not necessarily work against other isolates of the virus. Both pomegranate juice and fulvic acid contain acidic compounds. These compounds may bind to the lipid or the sugar chains on glycoproteins, and thereby neutralize the surface of the viruses and their isolates making them avirulant. These less virulant viruses may serve as antigens for the candidate vaccines. Unlike, neutralizing antibodies, which target only one glycoprotein, the compounds may bind to most of the glycoproteins, an action, which makes them broad spectrum inhibitors of HIV, influenza and their subtypes.
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Infection | Inflammation | Antibodies | Medical Microbiology
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Article Title: Antigenic Variation in Microbial Evasion of Immune Responses
 
How to Cite close
Kotwal, Girish J, and Kulkarni, Amod P(Dec 2007) Antigenic Variation in Microbial Evasion of Immune Responses. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001207.pub2]