title: A critical role for phagocytosis in resistance to malaria in iron-deficient mice.
abstract: Both iron-deficient anemia (IDA) and malaria remain a threat to children in developing countries. Children with IDA are resistant to malaria, but the reasons for this are unknown. In this study, we addressed the mechanisms underlying the protection against malaria observed in IDA individuals using a rodent malaria parasite, Plasmodium yoelii (Py). We showed that the intra-erythrocytic proliferation and amplification of Py parasites were not suppressed in IDA erythrocytes and immune responses specific for Py parasites were not enhanced in IDA mice. We also found that parasitized IDA cells were more susceptible to engulfment by phagocytes in vitro than control cells, resulting in rapid clearance of parasitized cells and that protection of IDA mice from malaria was abrogated by inhibiting phagocytosis. One possible reason for this rapid clearance might be increased exposure of phosphatidylserine at the outer leaflet of parasitized IDA erythrocytes. The results of this study suggest that parasitized IDA erythrocytes are eliminated by phagocytic cells, which sense alterations in the membrane structure of parasitized IDA erythrocytes.
authors.affiliation: Department of Microbiology and Immunology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Matsuzaki-Moriya
authors.forename: Liping
authors.initials: L
authors.lastname: Tu
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Ishida
authors.forename: Takashi
authors.initials: T
authors.lastname: Imai
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Suzue
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirai
authors.forename: Kohhei
authors.initials: K
authors.lastname: Tetsutani
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Hamano
authors.forename: Chikako
authors.initials: C
authors.lastname: Shimokawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Hisaeda
mesh_terms: D056704:Adaptive Immunity; D018798:Anemia, Iron-Deficiency / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000737:chemistry / Q000276:immunology* / Q000469:parasitology; D005434:Flow Cytometry; D007113:Immunity, Innate; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D008288:Malaria / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D008566:Membranes / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D010586:Phagocytes / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology*; D010718:Phosphatidylserines / Q000276:immunology; D010967:Plasmodium yoelii / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit; D010718:Phosphatidylserines; D002118:Calcium