Transcription and Expression of Plasmodium falciparum Histidine-Rich Proteins in Different Stages and Strains: Implications for Rapid Diagnostic Tests
2011

Studying Protein Levels in Malaria Parasites for Better Diagnosis

Sample size: 17 publication 10 minutes Evidence: moderate

Author Information

Author(s): Baker Joanne, Gatton Michelle L., Peters Jennifer, Ho Mei-Fong, McCarthy James S., Cheng Qin, Beeson James G.

Primary Institution: Australian Army Malaria Institute

Hypothesis

The amount of PfHRP produced by the parasite varies between different isolates, affecting detection by rapid diagnostic tests.

Conclusion

The levels of transcription of pfhrp2 and pfhrp3, and protein expression of PfHRP varied between different P. falciparum strains, which may impact the detection sensitivity of rapid diagnostic tests.

Supporting Evidence

  • Transcription of pfhrp2 and pfhrp3 was observed to vary relative to the control parasite K1.
  • The peak transcription was observed in ring-stage parasites.
  • Total protein levels were more constant relative to total mRNA transcription.
  • A maximum 24 fold difference in expression at ring-stage parasites relative to the K1 strain was observed.
  • Higher protein levels result in a lower detection limit on RDTs.

Takeaway

Different types of malaria parasites make different amounts of a protein that helps doctors test for the disease, which can make some tests work better than others.

Methodology

RNA and protein were extracted from various P. falciparum lines at different life cycle stages, and analyzed using quantitative real-time PCR, Western blot, and ELISA.

Potential Biases

Potential bias due to the use of cultured strains rather than natural infections.

Limitations

The study was conducted on laboratory strains, and the results may not fully represent field isolates.

Participant Demographics

Parasite strains from various geographic origins.

Statistical Information

P-Value

p<0.01

Statistical Significance

p<0.01

Digital Object Identifier (DOI)

10.1371/journal.pone.0022593

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