Involvement of gamma delta T cells in immunity to trypanosomiasis

Area of Science:

• Immunology
• Veterinary Science
• Parasitology

Background:

• Trypanosoma congolense infection poses a significant challenge to cattle health.
• Understanding the role of specific immune cells, like gamma delta T cells, is crucial for developing effective control strategies.

Purpose of the Study:

• To investigate the involvement of peripheral gamma delta T cells in the immune response of cattle to primary Trypanosoma congolense infection.
• To compare the gamma delta T cell response between trypanosusceptible Boran (Bos indicus) and trypanotolerant N'Dama (Bos taurus) cattle.

Main Methods:

• Flow cytometry was used to isolate and analyze peripheral gamma delta T cells.
• In vitro stimulation assays were performed using parasite antigens to assess T cell proliferation.
• T cell lines were established from infected N'Dama cattle for further characterization.

Main Results:

• Gamma delta T cells from trypanosusceptible Boran cattle showed negligible proliferative responses to parasite antigens.
• Gamma delta T cells and CD8+ T cells from trypanotolerant N'Dama cattle exhibited significant proliferation when stimulated with a specific 100,000-140,000 MW trypanosome antigen complex.
• Neither cattle species recognized trypanosome variable surface glycoprotein (VSG).
• Established N'Dama gamma delta T cell lines recognized the 100,000 MW complex antigen in a non-MHC restricted manner in one instance.

Conclusions:

• Peripheral gamma delta T cells contribute to the immune response against Trypanosoma congolense in cattle.
• Trypanotolerant N'Dama cattle demonstrate a more robust gamma delta T cell response compared to trypanosusceptible Boran cattle.
• The study identified a specific trypanosome antigen complex recognized by gamma delta T cells, suggesting potential targets for immune intervention.