Malarial Antibody Detection with an Engineered Yeast Agglutination Assay

Area of Science:

• Immunology
• Parasitology
• Biotechnology

Background:

• Current malaria diagnostics like microscopy and rapid tests struggle to detect low parasitemia, which is crucial for transmission and elimination.
• The Plasmodium falciparum merozoite surface protein-1 (PfMSP-1_19) contains an Epidermal Growth Factor-1 like domain (EGF1) that is a target for malaria antibodies.

Purpose of the Study:

• To develop a novel, sensitive, and potentially low-cost diagnostic assay for malaria antibody detection.
• To utilize modified Saccharomyces cerevisiae as antigen-displaying particles for malaria antibody capture.

Main Methods:

• Engineered yeast cells to display the PfMSP-1_19 EGF1 domain on their surface.
• Developed an agglutination assay by mixing antigen-displaying yeast with yeast displaying Protein A's Z domain.
• Visually assessed agglutination patterns (button vs. sheet) correlating with antibody levels in human serum.

Main Results:

• The engineered yeast successfully captured malaria antibodies.
• Distinct agglutination patterns (tight button for low, diffuse sheet for high antibody levels) were observed.
• Positive results were detected in malaria-positive human serum up to a 1:125 dilution.

Conclusions:

• The novel yeast-based agglutination assay demonstrates potential for sensitive malaria antibody detection.
• The use of inexpensive, easily produced yeast cells makes this assay suitable for local production and malaria surveillance.
• This assay could aid malaria elimination programs by providing accessible diagnostic information.