Chapter 44 – Mucosal Immune Response to Parasitic Infections

Publisher Summary The mucosal immune responses to parasitic infestations are a sequel of direct contact between the parasite and the host mucosa, the outcome of which is both host and parasite dependent. A competent host immune system, antigenicity of parasite constituents, and duration of contact—are factors contributing to the development of mucosal immunity. The intensity of the infection, the nature of the parasite, and specific host–parasite interactions determine the degree of tissue injury and manifestations of disease. Infection in the host's colon is mediated by the amebic galactose-inhibitable adherence lectin, allowing trophozoites to adhere to the colonic mucins. A Ca++ mediated lethal hit produced by E. histolytica trophozoites kills host cells. Clearance of E. histolytica is directly related to the development of the host's mucosal and humoral immune response. The mucosal antiamebic antibody response to E. histolytica differs from that to E. dispar. Contact time with the colonic mucosa may be for up to 1 year for E. dispar and up to 3 months for E. histolytica before eliciting a mucosal immune response.