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Differential protein expression and surface presentation generate high-frequency antigenic variation in Mycoplasma
P M Theiss1, M F Kim, K S Wise
1Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia 65212.
Infection and Immunity
|December 1, 1993
Summary
Mycoplasma fermentans exhibits rapid antigenic phase variation in its surface lipoproteins, creating diverse surface structures. This variation may impact host interactions and challenges in studying this potential human pathogen.
Area of Science:
- Microbiology
- Immunology
- Molecular Biology
Background:
- Mycoplasma fermentans is a wall-less prokaryote investigated as a potential human pathogen.
- Variable expression of surface lipoproteins among M. fermentans strains has been previously observed.
Purpose of the Study:
- To investigate the extent and nature of antigenic variation within Mycoplasma fermentans species.
- To understand the mechanisms generating surface phenotypic variation in M. fermentans.
Main Methods:
- Immunoscreening of M. fermentans type strain PG18 colonies using specific antibodies.
- Isolation and propagation of clonal isolates to establish isogenic lineages.
- Analysis of [35S]cysteine-labeled protein profiles and Western immunoblots of phase-variant clones.
Main Results:
- Marked heterogeneity in distinct surface lipoprotein expression was found in agar-grown colonies.
- High-frequency (10^-2 to 10^-5 per generation) antigenic phase variation was observed in isogenic lineages.
- Noncoordinate variation in expression of several distinct integral membrane proteins and differential epitope accessibility were documented.
Conclusions:
- Mycoplasma fermentans possesses a complex system for rapid changes in its surface mosaic.
- Antigenic phase variation underlies previously observed strain-specific antigenic differences.
- The dynamic surface variation likely affects mycoplasma-host interactions and in vivo study methods.