International Journal of Tropical Insect Science

, Volume 23, Issue 3, pp 197–205 | Cite as

Evidence for the Involvement of a Tsetse Midgut Lectin-Trypsin Complex in Differentiation of Bloodstream-Form Trypanosomes

  • L. U. Abubakar
  • G. Zimba
  • C. Wells
  • F. Mulaa
  • E. O. OsirEmail author
Research Article


We have previously described a bloodmeal-induced molecule (lectin-trypsin complex) from the midgut of the tsetse fly, Glossina longipennis, with both lectin and trypsin activities (Osir et al., 1995). In this paper, we report on the isolation of a similar molecule from the midguts of Glossina fuscipes fnscipes and provide direct evidence for its involvement in the development of African trypanosomes. The molecule (native Mr ∼65,700) has two non-covalently linked subunits, Mr ∼28,800 and Mr ∼35,700. The native molecule was found to be capable of inducing differentiation of bloodstream-form trypanosomes into procyclic (midgut forms) in vitro. In the assays, specific antibodies against procyclin were used to monitor the transformation of the bloodstream-form trypanosomes into procyclic forms. This induction was specifically inhibited by D-glucosamine. Cis-aconitate was also capable of inducing the transformation process with the same efficiency as that of the lectin-trypsin complex. While increasing the concentrations of the lectin-trypsin complex (≥100 μg protein/ml) in the incubation assays resulted into higher transformation rates, it also led to high parasite mortality. These results provide evidence for the involvement of the midgut lectin-trypsin complex in the differentiation of bloodstream-form trypanosomes within tsetse midgut.

Key Words

Glossina Tripanosoma brucei lectin trypsin 


Nous avons précédemment décrit une molécule induite par le repas de sang (un complexe lectine-trypsine) présente dans l’intestin moyen de la mouche tsé-tsé ’Glossina longipennis, ayant une activité lectine et trypsine (Osir et al., 1995). Dans ce papier, nous décrivons l’isolement d’une molécule similaire présente dans l’intestin moyen de Glossina fuscipes fuscines et démontrons son implication dans le développement des trypanosomes africains. La molécule (pure Mr ∼65,700) présente deux sous unités liées non covalentes, Mr ∼28,800 et Mr ∼35,700. La molécule pure est capable d’induire la différenciation des formes sanguines du trypanosome en formes pro-cycliques (intestin moyen) in vitro. Lors des essais, des anticorps spécifiques de la procycline ont été utilisés pour contrôler la transformation des formes sanguines du trypanosome en forme procycliques. Cette induction a été inhibée spécifiquement avec du D-glucosamine. Le cis-aconitate est également capable d’induire le processus de transformation avec une efficacité comparable à celle du complexe lectine-trypsine. Alors que l’augmentation des concentrations du complexe lectine-trypsine (≥100 μg protéine/ml) dans les essais d’incubation permet d’augmenter les taux de transformation, il induit également une importante mortalité du parasite. Ces résultats démontrent la participation du complexe lectine-trypsine de l’intestin moyen dans la différenciation des formes sanguines des trypanosomes dans l’intestin moyen de la mouche tsé-tsé.

Mots Clés

Glossina Tripanosoma brucei lectine trypsine 


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  1. Abubakar L., Osir E. O. and Imbuga M. O. (1995) Properties of a bloodmeal-induced midgut lectin from the tsetse fly, Glossina morsitans. Parasitol. Res. 81, 271–275.CrossRefGoogle Scholar
  2. Billker O., Lindo V., Panico M., Etienne A. E., Paxton T., Dell A., Rogers M., Sinden R. E. and Morris H. R. (1998) Identification of xanthurenic acid as the putative inducer of malaria development in the mosquito. Nature 392, 289–292.CrossRefGoogle Scholar
  3. Brun R. and Schönenberger M. (1981) Stimulating effect of citrate and cis-aconitate on the transformation of Trypanosoma brucei bloodstreams forms to procyclic forms in vitro. Z. Parasitenkd 66, 17–24.CrossRefGoogle Scholar
  4. Czichos J., Nonnengaesser C. and Overath P. (1986) Trypanosoma brucei: cis-aconitate and temperature reduction as triggers of synchronous transformation of bloodstream to procyclic trypomastigotes in vitro. Exp. Parasitol. 62, 283–291.CrossRefGoogle Scholar
  5. Frevert U., Herzberg F., Reinwald E. and Risse H. J. (1986) Morphological changes in Trypanosoma congolense after proteolytic removal of the surface coat. J. Ultrastruct. Mot. Struct. Res. 94, 140–148.CrossRefGoogle Scholar
  6. Ghiotto V., Brun R., Jenni L. and Hecker H. (1979) Trypanosoma brucei: Morphometric changes and loss of infectivity during transformation of bloodstream forms to procyclic culture forms in vitro. Exp. Parasitol. 48, 447–456.CrossRefGoogle Scholar
  7. Ibrahim E. A. R., Ingram G. A. and Molyneux D. H. (1984) Haemagglutinins and parasite agglutinins in haemolymph and gut of Glossina. Trop. Med. Parasitol. 35, 151–156.Google Scholar
  8. Imbuga M. O., Osir E. O., Darji N. and Otieno L. H. (1992a) Studies on tsetse midgut factors that induce differentiation of bloodstream T. brucei brucei in vitro. Parasitol. Res. 78, 10–15.CrossRefGoogle Scholar
  9. Imbuga M. O., Osir E. O. and Labongo V. L. (1992b) Inhibitory effect of T. brucei brucei on Glossina morsitans midgut trypsin in vitro. Parasitol. Res. 78, 273–276.CrossRefGoogle Scholar
  10. Isola E. L. D., Lammel E. M. and Gonzalez Cappa S. M. (1986) Trypanosoma cruzi: differentiation after interaction of epimastigotes and Triatoma infestons intestinal homogenate. Exp. Parasitol. 62, 329–335.CrossRefGoogle Scholar
  11. Laemmli U. K. (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227, 680–685.CrossRefGoogle Scholar
  12. Lanham S. M. and Godfrey D. G. (1970) Isolation of salivarian trypanosomes from man and other animals using DEAE cellulose. Exp. Parasitol. 28, 521–534.CrossRefGoogle Scholar
  13. Maudlin I. (1991) Transmission of African trypanosomiasis: interaction among tsetse immune system, symbionts and parasites. Adv. Disease Vector Res. 7, 117–148.CrossRefGoogle Scholar
  14. Maudlin I. and Welburn S. C. (1987) Lectin mediated establishment of midgut infections of Trypanosoma congolense and T. brucei in Glossina morsitans. Trop. Med. Parasitol. 38, 167–180.PubMedPubMedCentralGoogle Scholar
  15. Miller E. N. and Turner M. J. (1981) Analysis of antigenic types appearing in first relapse populations of clones of Trypanosoma brucei. Parasitology 82, 63–80.CrossRefGoogle Scholar
  16. Osir E. O., Abubakar L. and Imbuga M. O. (1995) Purification and characterization of a midgut lectin-trypsin complex from the tsetse fly, Glossina longipennis. Parasitol. Res. 81, 276–281.CrossRefGoogle Scholar
  17. Osir E. O., Imbuga M. O. and Onyango P. (1993) Inhibition of Glossina morsitans midgut trypsin activity by D-glucosamine. Parasitol. Res. 79, 93–97.CrossRefGoogle Scholar
  18. Overath P., Czichos J., Stock U. and Nonnengaesser C. (1983) Repression of glycoprotein synthesis and release of surface coat during transformation of Trypanosoma brucei. EMBO J. 2, 1721–1728.CrossRefGoogle Scholar
  19. Pearson T. W., Beecroft R. P., Welburn S. C., Ruepp S., Roditi I., Hwa K.-Y., Englund P. T., Wells C. W. and Murphy N. B. (2000) The major cell surface glycoprotein procyclin is a receptor for induction of a novel form of cell death in African trypanosomes in vitro. Mol. Biochem. Parasitol. 111, 333–349.CrossRefGoogle Scholar
  20. Richardson J. P., Beecroft R. P., Toison D. L., Liu M. K. and Pearson T. W. (1988) Procyclin: An unusual immunodominant glycoprotein surface antigen from the procyclic stage of African trypanosomes. Mol. Biochem. Parasitol. 31, 203–216.CrossRefGoogle Scholar
  21. Roditi I. and Pearson T. W. (1990) The procyclin coat of African trypanosomes (or the not-so-naked trypanosome). Parasitol. Today 6, 79–81.CrossRefGoogle Scholar
  22. Rolin S., Hanocq-Quertier J., Paturiaux-Hanocq F., Nolan D. P. and Pays E. (1998) Mild stress as a differentiation trigger in Trypanosoma brucei. Mol. Biochem. Parasitol. 93, 251–262.CrossRefGoogle Scholar
  23. Ruepp S., Furger A., Kurath U., Renggli C. K., Hemphill A., Brun R. and Roditi I. (1997) Survival of Trypanosoma brucei in the tsetse fly is enhanced by the expression of specific forms of procyclin. J. Cell. Biol. 137, 1369–1379.CrossRefGoogle Scholar
  24. Ruepp S., Kurath U., Renggli C. K., Brun R. and Roditi I. (1999) Glutamic acid/alanine-rich protein from Trypanosoma congolense is the functional equivalent of ‘EP’ procyclin from Trypanosoma brucei. Mol. Biochem. Parasitol. 98, 151–156.CrossRefGoogle Scholar
  25. Stiles J. K., Ingram G. A., Wallbanks K. R., Molyneux D. H., Maudlin I. and Welburn S. C. (1990) Identification of midgut trypanolysin and trypanoagglutinin In G. palpalis (Diptera: Glossinidae). Parasitology 101, 369–376CrossRefGoogle Scholar
  26. van den Abbelle J. and Decleir W. (1991) Study of vectorial capacity of Glossina spp. related to its digestive physiology and rearing conditions, pp. 1–19. In FAO/IAEA Seminar for Africa on Animal Trypanosomiasis: Tsetse Control, Diagnosis and Chemotherapy using Nuclear Techniques. KETRI, Muguga/Nairobi.Google Scholar
  27. Vassella E., Van Den Abbeele J., Bütikofer P., Renggli C. K., Furger A., Bran R. and Roditi I. (2000) A major surface glycoprotein of Trypanosoma brucei is expressed transiently during development and can be regulated post-transcriptionally by glycerol or hypoxia. Genes and Development 14, 615–626.PubMedGoogle Scholar
  28. Vickerman K. (1985) Developmental cycles and biology of pathogenic trypanosomes. British Med. Bull. 41, 105–114.CrossRefGoogle Scholar
  29. Welburn S. C., Maudlin I. and Ellis D. S. (1989) Rate of trypanosome killing by lectins in midgut of different species and strains of Glossina. Med. Vet. Entomol. 3, 77–82.CrossRefGoogle Scholar
  30. Yabu Y. and Takayanagi T. (1988) Trypsin-stimulated transformation of Trypanosoma brucei gambiense bloodstream forms to procyclic forms in vitro. Parasitol. Res. 74, 501–506.CrossRefGoogle Scholar

Copyright information

© ICIPE 2003

Authors and Affiliations

  • L. U. Abubakar
    • 1
  • G. Zimba
    • 2
  • C. Wells
    • 3
  • F. Mulaa
    • 4
  • E. O. Osir
    • 1
    Email author
  1. 1.International Centre of Insect Physiology and EcologyNairobiKenya
  2. 2.Bunda College of AgricultureUniversity of MalawiLilongweMalawi
  3. 3.International Livestock Research InstituteNairobiKenya
  4. 4.Department of BiochemistryUniversity of NairobiNairobiKenya

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