Effects of aflatoxin on the cellular immune system

Area of Science:

• Immunology
• Toxicology
• Mycotoxicology

Background:

• Aflatoxins are toxic secondary metabolites produced by Aspergillus fungi.
• Aflatoxin B1 is a known potent hepatotoxin and carcinogen.
• Previous observations indicated aflatoxin-induced thymic involution, suggesting immune system effects.

Purpose of the Study:

• To investigate the impact of aflatoxin B1 on cellular immunity parameters in guinea pigs.
• To assess the effects on cutaneous hypersensitivity, migration inhibition factor (MIF) activity, and lymphocyte transformation.

Main Methods:

• Guinea pigs were treated with varying doses of aflatoxin B1 (0.03–0.35 mg) for 3–5 weeks.
• Cellular immunity was assessed via cutaneous hypersensitivity tests (Nocardia asteroides sensitin).
• In vitro assays evaluated migration inhibition factor (MIF) activity and lymphocyte transformation (Phytohemagglutinin stimulation).

Main Results:

• A significant suppression of cutaneous hypersensitivity to Nocardia asteroides sensitin was observed in aflatoxin B1-treated guinea pigs.
• In vitro studies showed reductions in migration inhibition factor (MIF) activity.
• Depressed stimulation indices of peripheral blood lymphocytes were noted but did not reach statistical significance.

Conclusions:

• Aflatoxin B1 exposure demonstrably impairs cellular immune responses, particularly cutaneous hypersensitivity.
• While in vitro indicators of immune suppression were observed, further research is needed to confirm their statistical significance.
• These findings underscore the immunotoxic potential of aflatoxin B1.