# IMMUNOLOGICAL STUDIES OF T. CRUZI METACYCLIC STAGES

> **NIH NIH R01** · INDIANA STATE UNIVERSITY · 1988 · $121,622

## Abstract

Chagas' disease ensues after invasion and infection by metacyclic
trypomastigotes (MCs) of Trypanosoma cruzi.  Mice immunized with
irradiation-attenuated MCs resist infections by virulent MCs.  Fusions of
B-cells from such immunized mice with myelomas generate hybridomas which
after cloning, produce monoclonal antibodies (MAbs) that react with stage-
and species-specific antigens (Ags), neutralize MCs, or may when passively
transferred protect recipients.  MAbs will be selected from this panel on
the basis of their abilities to neutralize MCs and complex with epitopes on
different MC Ags as shown by Western blot analyses (WBA).  Antiidiotype
antibodies (AidAbs) will be prepared against each MAb.  MAb-immunoaffinity
chromatography will be used to isolate MC Ags.  The homogeneity and
molecular weight of each Ag will be assessed by sodium dodecyl
sulfate-polyacrylamide gel electrophoroesis and WBA.  The protein and
polysaccharide composition of each Ag will be correlated with the effects
of enzymatic and chemical treatments on serological reactivity.
Parasitemias and mortalities will be monitored in mice immunized with each
MC Ag or AidAb after challenge infections with MCs.  Mice receiving
passively transferred MAbs, similarly inoculated with MCs, will be
evaluated to compare their resistance to infections with the actively
immunized groups.  Interactions between MAb-defined Ags and host cell
receptors will be examined in cultured macrophages treated with each AidAb
or normal gamma globulins.  Macrophages will also be exposed to MCs treated
with each MAb or the normal globulins.  After intervals of incubation and
washing, the numbers of adherent MCs and infected cells will be enumerated
to determine whether AidAbs block receptors on macrophage surfaces or MAbs
affect MC attachment or internalization.  AidAb affinity chromatography
isolated receptors will be defined biochemically and both the MC Ags and
receptors will be localized by indirect fluorescent Ab microscopy.
Antisera from Mc-immunized and -infected mice and antisera from humans with
a cute and chronic Chagas' disease will be compared in serological tests
with each MC Ag and AidAb to establish their reactivities and the temporal
relationships of Ab synthesis.  The research will define the vaccine
potential of the MC Ags and AidAbs and may provide sensitive and specific
reagents for the serodiagnosis of infections in humans.

## Key facts

- **NIH application ID:** 3125822
- **Project number:** 5R01AI014642-08
- **Recipient organization:** INDIANA STATE UNIVERSITY
- **SAM.gov UEI:** WBLRF8Z4BEF6
- **Principal Investigator:** DONALD G DUSANIC
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $121,622
- **Award type:** 5
- **Project period:** 1978-02-01 → 1990-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3125822

## Citation

> US National Institutes of Health, RePORTER application 3125822, IMMUNOLOGICAL STUDIES OF T. CRUZI METACYCLIC STAGES (5R01AI014642-08). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3125822. Licensed CC0.

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