We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
INTEGRA BIOSCIENCES AG

Download Mobile App




DNA and Protein Composite Vaccine Produces Long Lasting Immunity Against Chagas Disease in Mice

By LabMedica International staff writers
Posted on 17 May 2015
Print article
Image: Micrograph showing T. cruzi (some marked by arrows) in the heart (Photo courtesy of Dr. Nisha J. Garg, University of Texas Medical Branch).
Image: Micrograph showing T. cruzi (some marked by arrows) in the heart (Photo courtesy of Dr. Nisha J. Garg, University of Texas Medical Branch).
A candidate vaccine for Chagas disease was found to induce long-lasting immunity against the Trypanosoma cruzi parasite in mice.

Chagas disease, or American trypanosomiasis, is a tropical parasitic disease caused by the protozoan Trypanosoma cruzi. It is spread mostly by insects known as Triatominae or kissing bugs. The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild and may include fever, swollen lymph nodes, headaches, or local swelling at the site of the bite. After eight to 12 weeks, individuals enter the chronic phase of disease, and in 60%–70% of cases it never produces further manifestations. The other 30%–40% of people develop further symptoms 10 to 30 years after the initial infection, including enlargement of the ventricles of the heart in 20%–30% of cases, which may lead to heart failure.

Investigators at the University of Texas Medical Branch (Galveston, USA) had previously obtained promising results with a vaccine that contained three particular parasite proteins. In the current study, they expanded on the earlier work by vaccinating mice with a combination of two of the T. cruzi proteins (TcG2 and TcG4), which had proven to be the most potent in provoking both an antibody and a T-cell immune response.

The investigators immunized C57BL/6 mice with the TcG2/TcG4 vaccine delivered by a DNA-prime/Protein-boost (D/P) approach. In this procedure the first injection contained DNA coding for the TcG2 and TcG4 proteins, and the second, three weeks later, contained a mix of the two proteins themselves. Some mice were also given a booster immunization three months later, which consisted of the mix of the two proteins (D/P/P regimen).

Results published in the May 7, 2015, online edition of the journal PLOS Pathogens revealed that mice challenged with T. cruzi immediately after immunization with the D/P vaccine were capable of controlling 90%–97% of the acute parasitemia and tissue parasite burden, and, subsequently, inflammatory infiltrate and tissue fibrosis were particularly absent in the heart and skeletal muscle of vaccinated mice.

D/P vaccination elicited CD4+ (30-38%) and CD8+ (22-42%) T-cells that maintained an effector phenotype up to 180 days following vaccination and were capable of responding to antigenic stimulus or challenge infection by a rapid expansion with type I cytokine production and cytolytic T-lymphocyte activity. Subsequently, challenge infection at 120 or 180 days following vaccination, resulted in two to three-fold lower parasite burden in vaccinated mice than was noted in unvaccinated/infected mice.

Summing up the results, the investigators said, "The TcG2/TcG4 D/P vaccine provided long-term anti-T. cruzi T-cell immunity, and booster immunization would be an effective strategy to maintain or enhance the vaccine-induced protective immunity against T. cruzi infection and Chagas disease. The next steps toward clinical studies in humans will include characterizing the quality and quantity of immunity to the vaccine candidates in naïve individuals."

Related Links:

University of Texas Medical Branch


Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
HLX
POCT Fluorescent Immunoassay Analyzer
FIA Go
New
Gold Member
TORCH Panel Rapid Test
Rapid TORCH Panel Test

Print article

Channels

Clinical Chemistry

view channel
Image: Reaching speeds up to 6,000 RPM, this centrifuge forms the basis for a new type of inexpensive, POC biomedical test (Photo courtesy of Duke University)

POC Biomedical Test Spins Water Droplet Using Sound Waves for Cancer Detection

Exosomes, tiny cellular bioparticles carrying a specific set of proteins, lipids, and genetic materials, play a crucial role in cell communication and hold promise for non-invasive diagnostics.... Read more

Molecular Diagnostics

view channel
Image: The cobas Malaria test is the first FDA-approved molecular test to screen U.S. blood donors for malaria (Photo courtesy of Roche)

First FDA-Approved Molecular Test to Screen Blood Donors for Malaria Could Improve Patient Safety

Malaria, a serious illness that often leads to death, is spread by a specific mosquito species that infect humans with a parasite. Other transmission modes include blood transfusions, organ transplants,... Read more

Hematology

view channel
Image: The low-cost portable device rapidly identifies chemotherapy patients at risk of sepsis (Photo courtesy of 52North Health)

POC Finger-Prick Blood Test Determines Risk of Neutropenic Sepsis in Patients Undergoing Chemotherapy

Neutropenia, a decrease in neutrophils (a type of white blood cell crucial for fighting infections), is a frequent side effect of certain cancer treatments. This condition elevates the risk of infections,... Read more

Pathology

view channel
Image: The medical office procedure detects the key biomarker in Parkinson’s and related neurodegenerative diseases (Photo courtesy of BIDMC)

Simple Skin Biopsy Test Detects Parkinson’s and Related Neurodegenerative Diseases

Parkinson's disease and a group of related neurodegenerative disorders known as synucleinopathies impact millions globally. These conditions, including Parkinson’s disease (PD), dementia with Lewy bodies... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.