Optimum conditions for the turkey lymphocyte transformation test.

Area of Science:

• Immunology
• Avian Biology

Background:

• Lymphocyte transformation tests (LTT) are crucial for assessing avian immune function.
• Establishing optimal conditions for turkey LTT is essential for accurate immunotoxicity and disease resistance studies.

Purpose of the Study:

• To determine the optimal conditions for turkey lymphocyte transformation assays.
• To identify key factors influencing mitogenic responses in turkey lymphocytes.

Main Methods:

• Turkey buffy-coat cells were prepared via slow centrifugation and washed.
• Lymphocytes were cultured with various mitogens (Concanavalin-A, Phytohemagglutinin-P, Pokeweed Mitogen) at different concentrations.
• Culture conditions including cell density, serum type and concentration, incubation temperature, and duration were optimized.
• Cell proliferation was measured by 3H-thymidine incorporation.

Main Results:

• Thrice-washed buffy-coat cells yielded optimal responses, while Ficoll-isolated lymphocytes showed reduced responsiveness.
• Maximum lymphocyte transformation was achieved with 2 x 10^7 cells/ml.
• Optimal serum supplementation involved 2.5% bovine fetal serum or 1.25% pooled turkey serum/autologous plasma.
• Optimal mitogen concentrations were determined as 5 µg/ml Concanavalin-A, 10 µg/ml Phytohemagglutinin-P, and 20 µg/ml Pokeweed Mitogen.
• Incubation at 40°C for 40-42 hours with 3H-thymidine pulsing in the final 16 hours improved results.

Conclusions:

• Specific preparation methods (washed buffy-coat cells) and culture conditions are critical for reliable turkey LTT.
• The established optimal conditions provide a robust protocol for evaluating turkey lymphocyte responses to mitogens.