Trypanosoma cruzi: different surface antigens of trypomastigotes are targets of lytic antibodies

Umezawa, Eufrosina Setsu; Stolf, Anna Maria Simonsen; Zingales, Bianca

doi:10.1016/0001-706x(93)90067-l

Cited by 14 publications

(7 citation statements)

References 21 publications

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“…In fact, the identification of CD8restricted protective CTL epitopes from T. cruzi TSA-1 protein allowed the development of an effective experimental DNA vaccine (Wizel et al, 1997). Likewise, the Experimental Parasitology 102 (2002) [89][90][91][92][93][94][95][96][97][98] www.elsevier.com/locate/yexpr humoral immunity induced by immunization can mediate protection (Araguth et al, 1988;Araujo and Morein, 1991;Gonzalez et al, 1991;Umezawa et al, 1993), and was shown to be required for immunization with an avirulent T. cruzi clone (Kumar and Tarleton, 1998). On the other hand, CD4 T1 cells generated by immunization are trypanocidal in vitro (Quanquin et al, 1999;Rodrigues et al, 1999), but its relevance as a protective mechanism in vivo remains to be demonstrated.…”

Section: Introductionmentioning

confidence: 99%

Trypanosoma cruzi: requirements for induction and maintenance of protective immunity conferred by immunization

Paiva¹,

Pyrrho²,

Ribeiro³

et al. 2002

Experimental Parasitology

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Immunization with CL-14-trypomastigotes generates efficient humoral and cellular responses against infective challenge. Herein, we investigated the relevance of these mechanisms in vivo. Immunization with live CL-14-trypomastigotes protected only part of beta2m(-/-) mice but efficiently protected perforin-knockout mice. Fixed CL-14-trypomastigotes could successfully immunize BALB/c, though live trypomastigotes lowered the requirements for doses and time intervals. Post-immune depletion of CD4 or CD8 subsets did not affect protection conferred by immunization, but switched the production of anti-Trypanosoma cruzi antibodies to IgG2a. Sublethal irradiation partially broke the resistance of immune mice, leading to development of late parasitemia. Passive serum transfer from immune mice conferred protection to nai;ve mice. Our results indicate that presentation of cytosolic antigens by MHC class I molecules is involved in the generation of immunity and suggest that the humoral response contributes to a great extent to keep CL-14-immunized mice protected against infective challenge.

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Section: Introductionmentioning

confidence: 99%

Trypanosoma cruzi: requirements for induction and maintenance of protective immunity conferred by immunization

Paiva¹,

Pyrrho²,

Ribeiro³

et al. 2002

Experimental Parasitology

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“…The alternative test for detection of LA, MbTFA, has a satisfactory sensitivity, but parasite capping and shedding can yield false negative results. Introducing fixation of parasites after the reaction of live target cells with the serum to be tested, Umezawa et al (9) reduced these problems. However, in this procedure parasites tend to form clumps, which stain uniformly even with negative sera.…”

Section: Discussionmentioning

confidence: 99%

“…MbIFA was performed as described by Krettli et al (3) with the modifications introduced by Umezawa et al (9).…”

Section: Test Methodsmentioning

confidence: 99%

In situ indirect fluorescent antibody: A new specific test to detect ongoing chagasic infections

Levy

Boainain

Kloetzel

1996

J. Clin. Lab. Anal.

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“…Complement-mediated lysis (CML) -the assay was done as described (Umezawa et al 1993). Table I shows the individual characteristics of the 18 acute phase chagasic patients from Catolé do Rocha as well as data on the time of manifestation of acute phase symptoms and period of fever.…”

Section: Methodsmentioning

confidence: 99%

Trypanosoma cruzi defined antigens in the serological evaluation of an outbreak of acute Chagas disease in Brazil (Catolé do Rocha, Paraíba)

Umezawa

Shikanai‐Yasuda

Gruber

et al. 1996

Mem. Inst. Oswaldo Cruz

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Immunoglobulin G and M humoral response to recombinant protein B13 and glycoconjugate LPPG Trypanosoma cruzi defined antigens was evaluated by ELISA in 18 patients in the acute phase of Chagas disease, who were contaminated on the same occasion. LPPG showed 100% positivity detecting both IgM and IgG antibodies, while positivity of 55-65% was observed for B13. An epimastigote alkaline extract (EPI) also showed high sensitivity for acute IgM (100%) and IgG (90%) antibodies. However LPPG had better discriminatory reactivity since with EPI two patients showed negative IgG, and several other sera presented OD values for IgG and IgM antibodies very close to the cutoff. Thus, it is suggested that detection of IgM antibodies by LPPG may be used for diagnosis of the acute phase of Chagas disease. An intense decline of IgG and IgM antibodies to the three antigens was observed in response to anti-T. cruzi chemotherapy in all acute phase patients. After treatment, six (30%) individuals maintained IgG positivity to EPI, LPPG, and B13 with lower reactivity than that measured at the acute phase. For comparison, serology of a group of 22 patients in the chronic phase of Chagas disease and also submitted to chemotherapy was determined. Positive IgM antibodies to EPI, LPPG and B13 were detected in only 5-9% cases. In all chronic-phase patients IgG antibodies highly reactive to the three antigens were present and no significant decrease resulted after benznidazole administration. These observations reinforce previous reports that treatment in the acute phase may reduce or eliminate the parasite.

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Trypanosoma cruzi: different surface antigens of trypomastigotes are targets of lytic antibodies

Cited by 14 publications

References 21 publications

Trypanosoma cruzi: requirements for induction and maintenance of protective immunity conferred by immunization

Trypanosoma cruzi: requirements for induction and maintenance of protective immunity conferred by immunization

In situ indirect fluorescent antibody: A new specific test to detect ongoing chagasic infections

Trypanosoma cruzi defined antigens in the serological evaluation of an outbreak of acute Chagas disease in Brazil (Catolé do Rocha, Paraíba)

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