Aflatoxin B₁ affects apoptosis and expression of death receptor and endoplasmic reticulum molecules in chicken spleen

Area of Science:

• Veterinary Toxicology
• Immunology
• Molecular Biology

Background:

• Aflatoxin B1 (AFB1) is a potent hepatocarcinogen and immunosuppressant produced by Aspergillus molds.
• AFB1-induced immunosuppression is linked to increased apoptosis in immune organs.
• The specific molecular mechanisms of AFB1-induced apoptosis in chicken splenocytes, particularly involving death receptors and endoplasmic reticulum (ER) stress, remain unclear.

Purpose of the Study:

• To investigate the effects of AFB1 on chicken splenocyte apoptosis.
• To examine the expression of death receptor and ER stress-related molecules in AFB1-exposed chicken spleens.

Main Methods:

• One hundred forty-four 1-day-old chickens were divided into control and AFB1-exposed (0.6 mg/kg) groups for 21 days.
• Histological examination of spleen tissues.
• TUNEL and flow cytometry assays to assess splenocyte apoptosis.
• Quantitative real-time PCR (qRT-PCR) to measure mRNA expression of specific genes.

Main Results:

• AFB1 exposure resulted in splenic congestion and lymphocytic depletion.
• Both TUNEL and flow cytometry confirmed excessive splenocyte apoptosis in AFB1-treated chickens.
• qRT-PCR revealed significantly elevated mRNA levels of Fas, FasL, TNF-α, TNF-R1, Caspase-3, Caspase-8, Caspase-10, Grp78, and Grp94 in the spleen.

Conclusions:

• AFB1 exposure induces significant apoptosis in chicken splenocytes.
• AFB1 alters the expression of death receptor pathway molecules (Fas, FasL, TNF-α, TNF-R1, Caspases) and ER stress markers (Grp78, Grp94) in the spleen.
• These molecular changes contribute to AFB1-induced immunosuppression in chickens.