Optimum conditions for the chicken lymphocyte transformation test

Area of Science:

• Avian immunology
• Cellular immunology
• Immunological assays

Background:

• Lymphocyte transformation tests (LTT) are crucial for assessing cell-mediated immunity in chickens.
• Standardizing LTT protocols is essential for reproducible and reliable results in avian research.

Purpose of the Study:

• To determine the optimal conditions for conducting chicken (Gallus gallus) lymphocyte transformation tests.
• To identify key factors influencing lymphocyte response to mitogenic stimulation in vitro.

Main Methods:

• Comparing lymphocyte isolation methods (buffy-coat vs. Ficoll separation).
• Evaluating different cell densities, serum concentrations (fetal bovine serum, chicken serum, autologous plasma), and mitogen concentrations (concanavalin A, phytohemagglutinin-P, pokeweed mitogen).
• Assessing incubation parameters including temperature (37°C vs. 40°C), CO2 concentration, and culture duration (40 vs. 64 hours) with 3H-thymidine incorporation.

Main Results:

• Thrice-washed buffy-coat cells yielded better responses than Ficoll-isolated lymphocytes.
• Optimal cell density was 2 x 10(7) cells/ml.
• Peak responses were achieved with 5% fetal bovine serum or 1.25% pooled chicken serum/autologous plasma.
• Incubation at 40°C with 5% CO2 and a 40-hour culture time (16-hour pulse) were optimal for Con A and PHA-P, while PWM required 64 hours.

Conclusions:

• Established optimal conditions for chicken LTT, including cell preparation, density, serum type/concentration, and incubation parameters.
• Demonstrated that optimal mitogen concentrations and incubation times can vary based on individual birds and specific mitogens.
• Provided a standardized protocol for reliable chicken lymphocyte proliferation assays, crucial for avian disease research and diagnostics.