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Quantitative imaging of Plasmodium transmission from mosquito to mammal


Plasmodium, the parasite that causes malaria, is transmitted by a mosquito into the dermis and must reach the liver before infecting erythrocytes and causing disease. We present here a quantitative, real-time analysis of the fate of parasites transmitted in a rodent system. We show that only a proportion of the parasites enter blood capillaries, whereas others are drained by lymphatics. Lymph sporozoites stop at the proximal lymph node, where most are degraded inside dendritic leucocytes, but some can partially differentiate into exoerythrocytic stages. This previously unrecognized step of the parasite life cycle could influence the immune response of the host, and may have implications for vaccination strategies against the preerythrocytic stages of the parasite.

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  1. 1

    Beier, J.C. Malaria parasite development in mosquitoes. Annu. Rev. Entomol. 43, 519–543 (1998).

  2. 2

    Frischknecht, F. et al. Imaging movement of malaria parasites during transmission by Anopheles mosquitoes. Cell. Microbiol. 6, 687–694 (2004).

  3. 3

    Boyd, M.F. & Kitchen, S.F. The demonstration of sporozoites in human tissues. Am. J. Trop. Med. Hyg. 19, 27–31 (1939).

  4. 4

    Ponnudurai, T., Lensen, A.H., van Gemert, G.J., Bolmer, M.G. & Meuwissen, J.H. Feeding behaviour and sporozoite ejection by infected Anopheles stephensi. Trans. R. Soc. Trop. Med. Hyg. 85, 175–180 (1991).

  5. 5

    Matsuoka, H., Yoshida, S., Hirai, M. & Ishii, A. A rodent malaria, Plasmodium berghei, is experimentally transmitted to mice by merely probing of infective mosquito, Anopheles stephensi. Parasitol. Int. 51, 17–23 (2002).

  6. 6

    Sidjanski, S. & Vanderberg, J.P. Delayed migration of Plasmodium sporozoites from the mosquito bite site to the blood. Am. J. Trop. Med. Hyg. 57, 426–429 (1997).

  7. 7

    Natarajan, R. et al. Fluorescent Plasmodium berghei sporozoites and pre-erythrocytic stages: a new tool to study mosquito and mammalian host interactions with malaria parasites. Cell. Microbiol. 3, 371–379 (2001).

  8. 8

    Franke-Fayard, B. et al. A Plasmodium berghei reference line that constitutively expresses GFP at a high level throughout the complete life cycle. Mol. Biochem. Parasitol. 137, 23–33 (2004).

  9. 9

    Vanderberg, J.P. Studies on the motility of Plasmodium sporozoites. J. Protozool. 21, 527–537 (1974).

  10. 10

    Vaughan, J.A., Scheller, L.F., Wirtz, R.A. & Azad, A.F. Infectivity of Plasmodium berghei sporozoites delivered by intravenous inoculation versus mosquito bite: implications for sporozoite vaccine trials. Infect. Immun. 67, 4285–4289 (1999).

  11. 11

    Krettli, A.U. & Dantas, L.A. Which routes do Plasmodium sporozoites use for successful infections of vertebrates? Infect. Immun. 68, 3064–3065 (2000).

  12. 12

    Meis, J.F. & Verhave, J.P. Exoerythrocytic development of malaria parasites. Adv. Parasitol. 27, 1–61 (1988).

  13. 13

    Grüner, A.C. et al. Insights into the P. y. yoelii hepatic stage transcriptome reveal complex transcriptional patterns. Mol. Biochem. Parasitol. 142, 184–192 (2005).

  14. 14

    Sacci, J.B., Jr. et al. Transcriptional analysis of in vivo Plasmodium yoelii liver stage gene expression. Mol. Biochem. Parasitol. 142, 177–183 (2005).

  15. 15

    Charoenvit, Y. et al. Plasmodium yoelii: 17-kDa hepatic and erythrocytic stage protein is the target of an inhibitory monoclonal antibody. Exp. Parasitol. 80, 419–429 (1995).

  16. 16

    Luke, T.C. & Hoffman, S.L. Rationale and plans for developing a non-replicating, metabolically active, radiation-attenuated Plasmodium falciparum sporozoite vaccine. J. Exp. Biol. 206, 3803–3808 (2003).

  17. 17

    Mueller, A.K., Labaied, M., Kappe, S.H. & Matuschewski, K. Genetically modified Plasmodium parasites as a protective experimental malaria vaccine. Nature 433, 164–167 (2005).

  18. 18

    Mueller, A.K. et al. Plasmodium liver stage developmental arrest by depletion of a protein at the parasite-host interface. Proc. Natl. Acad. Sci. USA 102, 3022–3027 (2005).

  19. 19

    Good, M.F. Genetically modified Plasmodium highlights the potential of whole parasite vaccine strategies. Trends Immunol. 26, 295–297 (2005).

  20. 20

    Tongren, J.E., Zavala, F., Roos, D.S. & Riley, E.M. Malaria vaccines: if at first you don't succeed.... Trends Parasitol. 20, 604–610 (2004).

  21. 21

    Bousso, P. & Robey, E. Dynamics of CD8+ T cell priming by dendritic cells in intact lymph nodes. Nat. Immunol. 4, 579–585 (2003).

  22. 22

    Hugues, S. et al. Distinct T cell dynamics in lymph nodes during the induction of tolerance and immunity. Nat. Immunol. 5, 1235–1242 (2004).

  23. 23

    Sumen, C., Mempel, T.R., Mazo, I.B. & von Andrian, U.H. Intravital microscopy: visualizing immunity in context. Immunity 21, 315–329 (2004).

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We thank A. Genovesio, C. Zimmer and J.-C. Olivo-Marin for help with tracking analysis, P. Roux for help with confocal microscopy, the members of the Center for Production and Infection of Anopheles of the Pasteur Institute for mosquitoes rearing, B. Boisson for help in RT-PCR and C. Janse for providing PbGFPCON parasites. We are grateful to G. Milon, C. Bourgouin, P. Sinnis, S. Mecheri and F. Zavala for comments on the manuscript. The work was supported by funds from the Pasteur Institute (Strategic project 'Grand Programme Horizontal Anopheles'), the Howard Hughes Medical Institute and the European Commission (FP6 BioMalPar Network of Excellence). R.A. was supported by the Pasteur Institute Grand Programme Horizontal fellowship and F.F. by a Human Frontier Science Program long-term fellowship. R.M. is a Howard Hughes Medical Institute International Scholar.

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Correspondence to Rogerio Amino or Friedrich Frischknecht or Robert Ménard.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Fig. 1

The number of sporozoites at the site of mosquito bite decreases with time. (PDF 53 kb)

Supplementary Table 1

Lymph sporozoites end their journey in the first draining lymph node. (PDF 19 kb)

Supplementary Movie 1

Sporozoite gliding in the skin. Two time-lapse series showing 200 seconds of sporozoite movement in the dermis of a hairless mouse at 3 minutes and 19 minutes after a single mosquito bite. The maximum projections of the fluorescent signal at the end of the respective time-lapse series show that the sporozoite gliding velocity decreases with time. Image series acquired with an epifluorescent wide-field microscope. (MOV 3296 kb)

Supplementary Movie 2

A sporozoite glides for 114 seconds with high velocity in the dermis, before slowing down upon encountering a blood vessel and invading the blood vessel wall; note the constriction (arrowhead) of the parasite at 282 seconds. After invading the blood vessel, the sporozoite rests several seconds inside the vessel before being taken away with the blood stream between 300 and 306 seconds. The red color represents projected fluorescent signals after injection of fluorescently labeled BSA, which was used to detect blood vessels with the spinning disk confocal microscope (BSA is taken up by endothelial and other dermal cells). The green signal of the sporozoite corresponds to a single confocal plane. Image series acquired with a spinning disk confocal microscope. (MOV 1608 kb)

Supplementary Movie 3

A sporozoite glides in the skin for 106 seconds before slowing down its speed and displaying a moving constriction (arrowhead). From 130 seconds onwards, the sporozoite drifts sideways for several hundred seconds. A second sporozoite (entering the field at 83 seconds) is also seen drifting sideways. The fluorescent signal of the sporozoite corresponds to a single confocal plane. Image series acquired with a spinning disk confocal microscope. (MOV 4761 kb)

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Figure 1: Sporozoite motility in the dermis.
Figure 2: Dermis sporozoites invade blood vessels.
Figure 3: Dermis sporozoites invade lymphatic vessels.
Figure 4: Sporozoite fate in the draining lymph node.