TY - JOUR
T1 - Extrahepatic exoerythrocytic forms of rodent malaria parasites at the site of inoculation
T2 - Clearance after immunization, susceptibility to primaquine, and contribution to blood-stage infection
AU - Voza, Tatiana
AU - Miller, Jessica L.
AU - Kappe, Stefan H.I.
AU - Sinnis, Photini
PY - 2012/6
Y1 - 2012/6
N2 - Plasmodium sporozoites are inoculated into the skin of the mammalian host as infected mosquitoes probe for blood. A proportion of the inoculum enters the bloodstream and goes to the liver, where the sporozoites invade hepatocytes and develop into the next life cycle stage, the exoerythrocytic, or liver, stage. Here, we show that a small fraction of the inoculum remains in the skin and begins to develop into exoerythrocytic forms that can persist for days. Skin exoerythrocytic forms were observed for both Plasmodium berghei and Plasmodium yoelii, two different rodent malaria parasites, suggesting that development in the skin of the mammalian host may be a common property of plasmodia. Our studies demonstrate that skin exoerythrocytic stages are susceptible to destruction in immunized mice, suggesting that their aberrant location does not protect them from the host's adaptive immune response. However, in contrast to their hepatic counterparts, they are not susceptible to primaquine. We took advantage of their resistance to primaquine to test whether they could initiate a blood-stage infection directly from the inoculation site, and our data indicate that these stages are not able to initiate malaria infection.
AB - Plasmodium sporozoites are inoculated into the skin of the mammalian host as infected mosquitoes probe for blood. A proportion of the inoculum enters the bloodstream and goes to the liver, where the sporozoites invade hepatocytes and develop into the next life cycle stage, the exoerythrocytic, or liver, stage. Here, we show that a small fraction of the inoculum remains in the skin and begins to develop into exoerythrocytic forms that can persist for days. Skin exoerythrocytic forms were observed for both Plasmodium berghei and Plasmodium yoelii, two different rodent malaria parasites, suggesting that development in the skin of the mammalian host may be a common property of plasmodia. Our studies demonstrate that skin exoerythrocytic stages are susceptible to destruction in immunized mice, suggesting that their aberrant location does not protect them from the host's adaptive immune response. However, in contrast to their hepatic counterparts, they are not susceptible to primaquine. We took advantage of their resistance to primaquine to test whether they could initiate a blood-stage infection directly from the inoculation site, and our data indicate that these stages are not able to initiate malaria infection.
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U2 - 10.1128/IAI.00246-12
DO - 10.1128/IAI.00246-12
M3 - Article
C2 - 22431651
AN - SCOPUS:85047688209
SN - 0019-9567
VL - 80
SP - 2158
EP - 2164
JO - Infection and immunity
JF - Infection and immunity
IS - 6
ER -