title: Helminth parasites alter protection against Plasmodium infection.
abstract: More than one-third of the world's population is infected with one or more helminthic parasites. Helminth infections are prevalent throughout tropical and subtropical regions where malaria pathogens are transmitted. Malaria is the most widespread and deadliest parasitic disease. The severity of the disease is strongly related to parasite density and the host's immune responses. Furthermore, coinfections between both parasites occur frequently. However, little is known regarding how concomitant infection with helminths and Plasmodium affects the host's immune response. Helminthic infections are frequently massive, chronic, and strong inductors of a Th2-type response. This implies that infection by such parasites could alter the host's susceptibility to subsequent infections by Plasmodium. There are a number of reports on the interactions between helminths and Plasmodium; in some, the burden of Plasmodium parasites increased, but others reported a reduction in the parasite. This review focuses on explaining many of these discrepancies regarding helminth-Plasmodium coinfections in terms of the effects that helminths have on the immune system. In particular, it focuses on helminth-induced immunosuppression and the effects of cytokines controlling polarization toward the Th1 or Th2 arms of the immune response.
authors.affiliation: Unidad de Biomedicina, Facultad de Estudios Superiores-Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios No. 1, Los Reyes Iztacala, 54090 Tlalnepantla, MEX, Mexico.
authors.forename: Víctor H
authors.initials: VH
authors.lastname: Salazar-Castañon
authors.affiliation: Laboratorio de Inmunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Batalla 5 de Mayo esquina Fuerte de Loreto, 09230 Iztapalapa, DF, Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: Legorreta-Herrera
authors.affiliation: Unidad de Biomedicina, Facultad de Estudios Superiores-Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios No. 1, Los Reyes Iztacala, 54090 Tlalnepantla, MEX, Mexico.
authors.forename: Miriam
authors.identifier: 0000-0003-2911-9390
authors.initials: M
authors.lastname: Rodriguez-Sosa
mesh_terms: D000818:Animals; D060085:Coinfection / Q000469:parasitology; D004195:Disease Models, Animal; D006376:Helminths / Q000502:physiology*; D006801:Humans; D008288:Malaria / Q000469:parasitology* / Q000517:prevention & control*; D010271:Parasites / Q000502:physiology*