Immune Evasion - Host Response to Infection

IMMUNE EVASION

Parasites exhibit a number of mechanisms that allow them to evade host immune response. Two such mechanisms are displayed by trypanosomes, which are able to exhibit both antigenic masking and antigenic variation. Masking means the parasite becomes coated with host components and therefore is not recognized as foreign. In addition parasites can undergo antigenic variation which results in surface antigens being changed during the course of an infection. The ultimate goal of these is that the hosts immune response is evaded. Parasites can also suppress the host’s immune response either to the parasite specifically or to foreign antigens in general. This, however, can cause a number of problems, as general immune suppression may make the individual more susceptible to secondary infection.