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Analysis of antigen switching rates in Trypanosoma brucei

Published online by Cambridge University Press:  06 April 2009

Gretel S. Lamont ,
R. S. Tucker  and
G. A. M. Cross
Gretel S. Lamont
Affiliation:
Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA
R. S. Tucker
Affiliation:
500 East 63rd Street, New York, NY 10021, USA
G. A. M. Cross
Affiliation:
Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA
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Summary

Previously quoted figures for the frequency of antigen switching in Trypanosoma brucei are based on incorrect assumptions. In order to determine the correct switching frequency, an equation was derived that takes the growth rates of the newly expressed antigen types into consideration as well as the proportion of switched trypanosomes and the number of generations since the population was antigenically homogeneous. When this equation was applied to published in vitro data, variable values were obtained for the switching frequency in clonal populations originally expressing one antigen type. The calculated most likely switching frequencies ranged from 1·4×10−7 to 3·5×10−6. This variation was probably caused by differences in the growth rates of the new antigen types in the population and failure to detect slow growing variants. To overcome these problems, an experimental procedure was developed to analyse the switching frequency in vitro. Trypanosomes were cloned and grown in parallel cultures. After an appropriate number of generations, cells expressing the original antigen type were destroyed and, from the proportion of cultures that contained new antigen types, the switching frequency was calculated. The technique minimized subculturing or other procedures that could distort the results. Although the method was optimized for analysing switching frequency, the values differed between experiments, ranging from 2·2×10−7 to 2·6×10−6 for one variant. Possible causes for the variations in switching frequency are discussed.

Type
Research Article
Information
Parasitology , Volume 92 , Issue 2 , April 1986 , pp. 355 - 367
Copyright
Copyright © Cambridge University Press 1986

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References

REFERENCES

Baltz, T., Baltz, D., Giroud, CH. & Crockett, J. (1985). Cultivation in a semi-defined medium of animal infective forms of Trypanosoma brucei, T. equiperdum, T. evansi, T. rhodesiense and T. gambiense. The EMBO Journal 4, 1273–7.CrossRefGoogle Scholar
Barry, J. D. & Emery, D. L. (1984). Parasite development and host responsesduring the establishment of Trypanosorna brucei infection transmitted by tsetse fly. Parasitoloqy 88, 67–84.CrossRefGoogle Scholar
Bernards, A., De Lange, T., Michels, P. A., Liu, A. Y. C., Husman, M. J. & Borst, P. (1984). Two modes of activation of a single surface antigen gene of Trypanosoma brucei. Cell 36, 163–70.CrossRefGoogle ScholarPubMed
Borst, P. & Cross, C. A. M. (1982). Molecular basis for trypanosome antigenic variation. Cell 29, 291–303.CrossRefGoogle ScholarPubMed
Brun, R., Jenni, L., Schonenberger, M. & Schell, K. F. (1981). In vitro cultivation of bloodstream forms of Trypanosoma brucei, T. rhodesiense and T. gambiensei. Journal of Protozoology 28, 470–9.CrossRefGoogle Scholar
Cross, C. A. M. (1975). Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei. Parasitology 71, 393–417.CrossRefGoogle ScholarPubMed
Cross, G. A. M. (1984 a). Structure of the variant glycoproteins and surface coat of Trypanosonza brucei. Philosophical Transactions of The Royal Society, B 307, 3–12.Google ScholarPubMed
Cross, C. A. M. (1984 b). Release and purification of Trypanosonia brucei variant surface glycoprotein. Journal of Cellular Biochemistry 24, 79–90.CrossRefGoogle ScholarPubMed
Doyle, J. J. (1977). Antigenic variation in the salivarian trypanosomes. In Immunity to Blood Parasites of Animals and Man (ed. Miller, L. H., Pino, J. A. and McKelvey, J. J.), pp. 31–63. London and New York: Plenum Press.CrossRefGoogle Scholar
Doyle, J. J., Hiauini, H., Hiau, K., Lupton, E. N. & Caoss, G. A. M. (1980). Antigenic variation in clones of animal-infective Trypanosoma brucei derived and maintained in vitro. Parasitology 80, 359–69.CrossRefGoogle ScholarPubMed
Duszenko, M., Ferguson, M. A. J., Lamont, C. S., Rifein, M. R. & Cross, G. A. M. (1985). Cysteine eliminates the feeder cell requirement for cultivation of Trypanosonia brucei bloodstream forms in vitro. Journal of Experimental Medicine 162, 1256–63.CrossRefGoogle ScholarPubMed
Englund, P. T., Hajduk, S. L. & Marini, J. C. (1982). The molecular biology of trypanosomes. Annual Review of Biochemistry 51, 695–726.CrossRefGoogle ScholarPubMed
Esser, K. M. & Shioenbechler, M. J. (1985). Expression of two distinct variant surface glycoproteins on individual African trypanosomes during antigenic switching. Science 229, 190–3.CrossRefGoogle Scholar
Hinui, H., Doyle, J. J. & Hirulul, K. (1977). African trypanosomes: Cultivation of animal-infective Trypanosoma brucei in vitro. Science 196, 992–4.Google Scholar
Hirumi, H., Hmurui, K., Doyle, J. J. & Cross, G. A. M. (1980). In Vitro cloning of animal-infective bloodstream forms of Trypanosoma brucei. Parasitology 80, 371–82.CrossRefGoogle ScholarPubMed
Kosinskt, R. J. (1980). Antigenic variation in trypanosonies: a computer analysis of variant order. Parasitology 80, 343–57.CrossRefGoogle Scholar
Laurent, M., Pays, E., Van Dee Werf, A., Aerts, D., Magnus, E., Van Meirvenne, N. & Stetnert, M. (1984). Translocation alters the activation rate of a trypanosome surface antigen gene. Nucleic Acids Research 12. 8319–28.CrossRefGoogle ScholarPubMed
Lenardo, M. J., Rice-Ficht, A. C., Kelly, C., Esser, K. M. & Donelson, J. E. (1984). Characteri zation of the genes specifying two metacyclic variable antigen types in Trypanosoma brucei rhodesiense. Proceedings of the National Academy of Sciences, USA 81, 6642–6.CrossRefGoogle Scholar
Luria, S. E. & Delbruck, M. (1943). Mutations of bacteria from virus sensitivity to virus resistance. Genetics 28, 491–511.CrossRefGoogle ScholarPubMed
Michels, P. A. M., Van Der Ploeg, L. H. T., Liu, A. Y. C. & Boast, P. (1984). The inactivation and reactivation of an expression linked gene copy for a variant surface glycoprotein in Trypanosoma brucei. The EMBO Journal 3, 1345–51.CrossRefGoogle ScholarPubMed
Miller, E. N. & Turner, M. J. (1981). Analysis of antigenic types appearing in first relapse population of clones of Trypanosoma brucei. Parasitology 82, 63–80.CrossRefGoogle ScholarPubMed
Myler, P. J., Allen, A. L., Agabian, N. & Stuart, K. (1985). Antigenic variation in clones of Trypanosoma brucei grown in immune-deficient mice. Infection and Immunity 47, 684–90.CrossRefGoogle ScholarPubMed
Nantulya, V. M. & Doyle, J. J. (1977). Stabilization and preservation of the antigenic specificity of Trypanosoma (Trypanozoon) brucei variant specific surface antigens by mild fixation techniques. Acta Tropica 34, 313–20.Google ScholarPubMed
Pays, E., Van Assel, S., Laurent, M., Darville, M., Vervoort, T., Van Meirvenne, N. & Steinert, M. (1983 a). Gene conversion as a mechanism for antigenic variation in trypanosomes. cell 34, 371–81.CrossRefGoogle ScholarPubMed
Pays, E., Delauw, M-F., Van Assel, S., Laurent, M., Vervoort, T., Van Meirvenne, N. & Steinert, M. (1983 b). Modifications of Trypanosoma b. brucei antigen gene repertoire by different recombinatorial mechanisms. Cell 35, 721–31.CrossRefGoogle Scholar
Seed, J. R. (1978). Competition among serologically different clones of Trypanosorna brucei gambiense in vivo. Journal of Protozoology 25, 526–9.CrossRefGoogle Scholar
Seed, J. R., Edwards, R. & Sechelski, J. (1984). The ecology of antigenic variation. Journal of Protozoology 31, 48–53.CrossRefGoogle ScholarPubMed
Seed, J. R. & Effron, H. G. (1973). Simultaneous presence of different antigenic populations of Trypanosoina brucei gambiense in vivo. Journal of Protozoology 25, 526–9.CrossRefGoogle Scholar
Tanner, M., Jenni, L., Hecker, H. & Brun, R. (1980). Characterization of Trypanosoma brucei isolated from lymph nodes of rats. Parasitology 80, 383–91.CrossRefGoogle ScholarPubMed
Turner, M. J. (1984). Antigenic variation in its biological context. Philosophical Transactions of the Royal Society, B 307, 27–40.Google ScholarPubMed
Van Dee Ploeg, L. H. T., Valerlo, D., De Lange, T., Bernards, A., Borst, P. & Grosveld, T. G. (1982). An analysis of cosmid clones of nuclear DNA from Trypanosoma brucei shows that the genes for variant surface glycoproteins are clustered in the genome. Nucleic Acids Research 10, 5905–23.CrossRefGoogle Scholar
Van Meirvenne, N., Janssens, P. G. & Magnus, E. (1975). Antigenic variation in syringe passaged populations of Trypanosoma (Trypanozoon) brucei. Rationalization of the experimental approach. Annales de la société Belge de Médecine Tropicale 55, 1–23.Google ScholarPubMed
Vickerman, K. (1969). On the surface coat and flagellar adhesion in trypanosomes. Journal of Cell Science 5, 163–93.CrossRefGoogle ScholarPubMed