Developmentally regulated expression by Trypanosoma cruzi of molecules that accelerate the decay of complement C3 convertases

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.85.1.193· OSTI ID:6464634

Rimoldi, M T; Sher, A; Heiny, A; Lituchy, A; Hammer, C H; Joiner, K

The authors recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 99 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results suggested that CMT and tissue-culture-derived trypomastigotes (TCT), which also activate the alternative pathway poorly, might produce a molecule capable of interfering with factor B binding to C3b. They now demonstrate that CMT and TCT lysates, as well as molecules spontaneously shed from CMT and TCT but not Epi, accelerate decay of /sup 125/I-labeled factor Bb from the alternative-pathway C3 convertase (C3bBb) assembled on zymosan or Epi and also accelerate decay of the classical-pathway C3 convertase (C4b2a) on sheep erythrocytes. Parasites metabolically labeled with (/sup 35/S)methionine spontaneously shed a limited number of radioactive components, ranging in molecular mass from 86 to 155 kDa for trypomastigotes and 25 to 80 kDa for Epi. Decay-accelerating activity within supernatants is inactivated by papain and is coeluted with /sup 35/S-containing polypeptides on FPLC anion-exchange chromatography, suggesting that the active constituents are protein molecules. Molecules with decay-accelerating activity may explain the developmentally regulated resistance to complement-mediated lysis in infective and vertebrate stages for T. cruzi life cycle.

• Research Organization: National Institute of Allergy and Infectious Diseases, Bethesda, MD (USA)
• OSTI ID: 6464634
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 85:1; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BLOOD SERUM
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
COMPLEMENT
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
HYDROLASES
IMMUNOLOGY
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
IODIDES
IODINE 125
IODINE COMPOUNDS
IODINE ISOTOPES
ION EXCHANGE CHROMATOGRAPHY
ISOTOPES
LABELLING
LIGHT NUCLEI
LIPOTROPIC FACTORS
LYSIS
MASTIGOPHORA
METHIONINE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PARASITES
PHOSPHORS
PROTEINS
RADIOISOTOPES
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM IODIDES
SULFUR 35
SULFUR ISOTOPES
TRYPANOSOMA