Cell-mediated immunity against turkey coronaviral enteritis (bluecomb)

Area of Science:

• Veterinary Immunology
• Avian Pathology
• Virology

Background:

• Turkey coronavirus (TCV) causes enteritis in turkeys.
• Understanding the cell-mediated immune response is crucial for developing effective immunity strategies.
• Assessing lymphocyte reactivity provides insights into immune status.

Purpose of the Study:

• To develop and validate a whole blood culture technique for evaluating cell-mediated immunity in turkeys infected with TCV.
• To quantitatively assess lymphocyte proliferation in response to mitogens and TCV antigen.
• To determine the role of cell-mediated immunity in protection against turkey coronaviral enteritis.

Main Methods:

• A whole blood culture technique was established for in vitro lymphocyte reactivity assessment.
• Lymphocyte blastogenesis was quantified using [125I]deoxyuridine uptake.
• Reactivity was measured against concanavalin A, phytohemagglutinin-P, and TCV antigen.

Main Results:

• Stimulation indices were significantly higher (P < 0.05) in TCV-infected turkeys compared to controls.
• Specific TCV responses were detected, indicating an adaptive cell-mediated immune reaction.
• The whole blood lymphocyte transformation assay proved effective in detecting immune responses.

Conclusions:

• Cell-mediated immunity plays a significant role in protection against turkey coronaviral enteritis.
• The whole blood lymphocyte transformation assay is a practical in vitro tool for monitoring cell-mediated immunity in TCV infections.
• This assay can aid in evaluating the immune status and vaccine efficacy in turkeys.