Decrease in establishment of Haemonchus contortus caused by inoculation of a Taenia hydatigena larvae vesicular...

Area of Science:

• Veterinary Parasitology
• Immunology
• Helminthology

Background:

• Haemonchus contortus is a major gastrointestinal nematode parasite of small ruminants.
• Understanding immune responses to parasitic infections is crucial for developing effective control strategies.
• Taenia hydatigena larvae vesicular concentrate (ThLVC) has shown potential immunomodulatory effects.

Purpose of the Study:

• To evaluate the effect of ThLVC administration on experimental Haemonchus contortus infection in lambs.
• To investigate the immune responses, including eosinophilia and lymphocyte populations, following ThLVC treatment and infection.

Main Methods:

• Lambs were treated with ThLVC prior to experimental infection with H. contortus.
• Blood eosinophil counts (BE), fecal egg counts (FEC), and adult parasite burdens (AP) were assessed.
• Lymphocyte populations (CD4+, gamma-delta, plasma cells) in abomasal lymph nodes (ALN) and abomasal wall (AW) were analyzed.

Main Results:

• ThLVC administration led to increased blood eosinophils (BE) in lambs.
• Lambs receiving ThLVC showed reduced fecal egg counts (FEC) and adult parasite burdens (AP).
• ThLVC modulated lymphocyte responses, increasing CD4+ lymphocytes in the abomasal wall and showing a correlation between gamma-delta lymphocytes and parasite presence.

Conclusions:

• ThLVC administration prior to H. contortus inoculation induces eosinophilia and provides partial protection against parasite establishment in lambs.
• The protective effect of ThLVC is likely mediated by stimulating various immune cells, including T lymphocytes, beyond just eosinophils.
• These findings suggest ThLVC as a potential tool for enhancing host resistance against H. contortus infections.