Trypanosoma congolense: proliferative responses and interleukin production in lymph node cells of infected cattle

Area of Science:

• Veterinary Immunology
• Parasitology
• Molecular Biology

Background:

• Trypanosoma congolense causes significant disease in cattle.
• Understanding the host immune response is crucial for developing effective control strategies.
• T-cell responses are vital for controlling parasitic infections.

Purpose of the Study:

• To investigate T-cell-mediated immune responses in cattle during primary Trypanosoma congolense infection.
• To identify specific parasite antigens that elicit cellular immune responses.
• To determine the location and characteristics of these T-cell responses.

Main Methods:

• Cattle were infected with Trypanosoma congolense.
• Lymph node cells and peripheral blood mononuclear cells were isolated.
• Antigen-specific proliferation assays were performed using variable surface glycoprotein, congopain, and heat-shock protein.
• Cytokine production (IL-2, IFN-gamma) and mRNA expression (IL-2, IL-4, IFN-gamma) were analyzed.

Main Results:

• Highest proliferative T-cell responses were observed in the second week post-infection.
• Significant responses were detected in lymph node cells draining the infection site, but not in peripheral blood.
• Antigen stimulation induced production of IL-2 and IFN-gamma in lymph node cells.
• Expression of IL-2, IL-4, and IFN-gamma mRNA was confirmed in stimulated lymph node cells.

Conclusions:

• Cattle mount a localized T-cell immune response in draining lymph nodes against Trypanosoma congolense antigens during primary infection.
• The cellular immune response involves the production of key cytokines like IL-2 and IFN-gamma.
• Invariant antigens like congopain and heat-shock protein are targets of the T-cell response, alongside VSG.