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Longitudinal analysis of Plasmodium sporozoite motility in the dermis reveals component of blood vessel recognition.

Hopp CS, Chiou K, Ragheb DR, Salman A, Khan SM, Liu AJ, Sinnis P - Elife (2015)

Bottom Line: How sporozoites locate and enter a blood vessel is a critical, but poorly understood process.Our data suggest that sporozoites exhibit two types of motility: in regions far from blood vessels, they exhibit 'avascular motility', defined by high speed and less confinement, while in the vicinity of blood vessels their motility is more constrained.Imaging of sporozoites with mutations in key adhesive proteins highlight the importance of the sporozoite's gliding speed and its ability to modulate adhesive properties for successful exit from the inoculation site.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States.

ABSTRACT
Malaria infection starts with injection of Plasmodium sporozoites by an Anopheles mosquito into the skin of the mammalian host. How sporozoites locate and enter a blood vessel is a critical, but poorly understood process. In this study, we examine sporozoite motility and their interaction with dermal blood vessels, using intravital microscopy in mice. Our data suggest that sporozoites exhibit two types of motility: in regions far from blood vessels, they exhibit 'avascular motility', defined by high speed and less confinement, while in the vicinity of blood vessels their motility is more constrained. We find that curvature of sporozoite tracks engaging with vasculature optimizes contact with dermal capillaries. Imaging of sporozoites with mutations in key adhesive proteins highlight the importance of the sporozoite's gliding speed and its ability to modulate adhesive properties for successful exit from the inoculation site.

No MeSH data available.


Related in: MedlinePlus

Generation of mutant TRAP-VAL parasites in the marker-free P. berghei line expressing mCherry under control of the uis4 promoter.(A) Schematic representation of the strategy used to replace the endogenous TRAP locus with the TRAP-VAL copy of the gene. The transfection plasmid (pTRAP) contains 500 bp of TRAP 5′-UTR (red line), the selectable marker hDHFR (black box) with its 5′- and 3′-UTRs, and the TRAP gene (red box) flanked by its 5′- and 3′-UTRs (red lines). Dashed black lines indicate the location of homologous recombination with the endogenous TRAP locus. Location of primers used for PCR analysis is shown. (B) Diagnostic PCRs were used to verify successful recombination at the 5′ end (primers A and B) and the 3′ end (primers C and E). Primers F and G (shown in panel A) were used to amplify the TRAP open reading frame for sequencing to confirm the presence of the desired mutations. See Supplementary file 1 for primer sequences. (C) Confirmation of reduced infectivity of TRAP-VAL sporozoites determined by prepatent period after exposure to the bites of mosquitoes infected with wild-type control or TRAP-VAL parasites.DOI:http://dx.doi.org/10.7554/eLife.07789.013
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fig3s2: Generation of mutant TRAP-VAL parasites in the marker-free P. berghei line expressing mCherry under control of the uis4 promoter.(A) Schematic representation of the strategy used to replace the endogenous TRAP locus with the TRAP-VAL copy of the gene. The transfection plasmid (pTRAP) contains 500 bp of TRAP 5′-UTR (red line), the selectable marker hDHFR (black box) with its 5′- and 3′-UTRs, and the TRAP gene (red box) flanked by its 5′- and 3′-UTRs (red lines). Dashed black lines indicate the location of homologous recombination with the endogenous TRAP locus. Location of primers used for PCR analysis is shown. (B) Diagnostic PCRs were used to verify successful recombination at the 5′ end (primers A and B) and the 3′ end (primers C and E). Primers F and G (shown in panel A) were used to amplify the TRAP open reading frame for sequencing to confirm the presence of the desired mutations. See Supplementary file 1 for primer sequences. (C) Confirmation of reduced infectivity of TRAP-VAL sporozoites determined by prepatent period after exposure to the bites of mosquitoes infected with wild-type control or TRAP-VAL parasites.DOI:http://dx.doi.org/10.7554/eLife.07789.013


Longitudinal analysis of Plasmodium sporozoite motility in the dermis reveals component of blood vessel recognition.

Hopp CS, Chiou K, Ragheb DR, Salman A, Khan SM, Liu AJ, Sinnis P - Elife (2015)

Generation of mutant TRAP-VAL parasites in the marker-free P. berghei line expressing mCherry under control of the uis4 promoter.(A) Schematic representation of the strategy used to replace the endogenous TRAP locus with the TRAP-VAL copy of the gene. The transfection plasmid (pTRAP) contains 500 bp of TRAP 5′-UTR (red line), the selectable marker hDHFR (black box) with its 5′- and 3′-UTRs, and the TRAP gene (red box) flanked by its 5′- and 3′-UTRs (red lines). Dashed black lines indicate the location of homologous recombination with the endogenous TRAP locus. Location of primers used for PCR analysis is shown. (B) Diagnostic PCRs were used to verify successful recombination at the 5′ end (primers A and B) and the 3′ end (primers C and E). Primers F and G (shown in panel A) were used to amplify the TRAP open reading frame for sequencing to confirm the presence of the desired mutations. See Supplementary file 1 for primer sequences. (C) Confirmation of reduced infectivity of TRAP-VAL sporozoites determined by prepatent period after exposure to the bites of mosquitoes infected with wild-type control or TRAP-VAL parasites.DOI:http://dx.doi.org/10.7554/eLife.07789.013
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594146&req=5

fig3s2: Generation of mutant TRAP-VAL parasites in the marker-free P. berghei line expressing mCherry under control of the uis4 promoter.(A) Schematic representation of the strategy used to replace the endogenous TRAP locus with the TRAP-VAL copy of the gene. The transfection plasmid (pTRAP) contains 500 bp of TRAP 5′-UTR (red line), the selectable marker hDHFR (black box) with its 5′- and 3′-UTRs, and the TRAP gene (red box) flanked by its 5′- and 3′-UTRs (red lines). Dashed black lines indicate the location of homologous recombination with the endogenous TRAP locus. Location of primers used for PCR analysis is shown. (B) Diagnostic PCRs were used to verify successful recombination at the 5′ end (primers A and B) and the 3′ end (primers C and E). Primers F and G (shown in panel A) were used to amplify the TRAP open reading frame for sequencing to confirm the presence of the desired mutations. See Supplementary file 1 for primer sequences. (C) Confirmation of reduced infectivity of TRAP-VAL sporozoites determined by prepatent period after exposure to the bites of mosquitoes infected with wild-type control or TRAP-VAL parasites.DOI:http://dx.doi.org/10.7554/eLife.07789.013
Bottom Line: How sporozoites locate and enter a blood vessel is a critical, but poorly understood process.Our data suggest that sporozoites exhibit two types of motility: in regions far from blood vessels, they exhibit 'avascular motility', defined by high speed and less confinement, while in the vicinity of blood vessels their motility is more constrained.Imaging of sporozoites with mutations in key adhesive proteins highlight the importance of the sporozoite's gliding speed and its ability to modulate adhesive properties for successful exit from the inoculation site.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States.

ABSTRACT
Malaria infection starts with injection of Plasmodium sporozoites by an Anopheles mosquito into the skin of the mammalian host. How sporozoites locate and enter a blood vessel is a critical, but poorly understood process. In this study, we examine sporozoite motility and their interaction with dermal blood vessels, using intravital microscopy in mice. Our data suggest that sporozoites exhibit two types of motility: in regions far from blood vessels, they exhibit 'avascular motility', defined by high speed and less confinement, while in the vicinity of blood vessels their motility is more constrained. We find that curvature of sporozoite tracks engaging with vasculature optimizes contact with dermal capillaries. Imaging of sporozoites with mutations in key adhesive proteins highlight the importance of the sporozoite's gliding speed and its ability to modulate adhesive properties for successful exit from the inoculation site.

No MeSH data available.


Related in: MedlinePlus