TY - JOUR
T1 - The role of rosetting in the multiplication of Plasmodium falciparum
T2 - Rosette formation neither enhances nor targets parasite invasion into uninfected red cells
AU - Clough, Barbara
AU - Atilola, F. Abiola
AU - Pasvol, Geoffrey
PY - 1998
Y1 - 1998
N2 - The effect of rosette formation on the multiplication in vitro of Plasmodium falciparum was studied in order to establish whether rosetting acts as a major virulence factor in the pathogenesis of severe malaria by facilitating invasion of uninfected red cells. Invasion rates for rosetting (R+) and non-rosetting (R-) parasites selected from the same clone, PA1, of E falciparum were similar over a range of starting parasite concentrations when assayed in both static cultures and conditions of shear stress comparable with microvascular flow. However, incubation of both R+ and R- parasites under simulated conditions of flow led to decreased invasion and fewer multiply-infected red cells as we have previously observed. Studies using fluorescently labelled red cells or reticulocytes demonstrated that rosetting did not alter the rates of invasion or target merozoites into the uninfected cells comprising a rosette. Preferential invasion of reticulocytes occurred regardless of resetting or conditions of flow. Although the role of rosetting in the pathogenesis of malaria might relate to microvascular obstruction or perhaps the restriction of phagocytosis, our data suggest that rosetting does not play a role in the invasion or targeting of parasites into uninfected cells, eliminating this mechanism to explain the association of virulence with the rosetting parasite phenotype.
AB - The effect of rosette formation on the multiplication in vitro of Plasmodium falciparum was studied in order to establish whether rosetting acts as a major virulence factor in the pathogenesis of severe malaria by facilitating invasion of uninfected red cells. Invasion rates for rosetting (R+) and non-rosetting (R-) parasites selected from the same clone, PA1, of E falciparum were similar over a range of starting parasite concentrations when assayed in both static cultures and conditions of shear stress comparable with microvascular flow. However, incubation of both R+ and R- parasites under simulated conditions of flow led to decreased invasion and fewer multiply-infected red cells as we have previously observed. Studies using fluorescently labelled red cells or reticulocytes demonstrated that rosetting did not alter the rates of invasion or target merozoites into the uninfected cells comprising a rosette. Preferential invasion of reticulocytes occurred regardless of resetting or conditions of flow. Although the role of rosetting in the pathogenesis of malaria might relate to microvascular obstruction or perhaps the restriction of phagocytosis, our data suggest that rosetting does not play a role in the invasion or targeting of parasites into uninfected cells, eliminating this mechanism to explain the association of virulence with the rosetting parasite phenotype.
KW - Invasion
KW - Plasmodium falciparum
KW - Reticulocytes
KW - Rosetting
KW - Virulence
UR - http://www.scopus.com/inward/record.url?scp=0031982752&partnerID=8YFLogxK
U2 - 10.1046/j.1365-2141.1998.00534.x
DO - 10.1046/j.1365-2141.1998.00534.x
M3 - Article
C2 - 9450797
AN - SCOPUS:0031982752
SN - 0007-1048
VL - 100
SP - 99
EP - 104
JO - British Journal of Haematology
JF - British Journal of Haematology
IS - 1
ER -