Immunization against experimental rabbit cysticercosis using liposome-associated antigen preparations

Area of Science:

• Veterinary Parasitology
• Immunology
• Biotechnology

Background:

• Taenia pisiformis infection causes significant economic losses in the rabbit industry.
• Effective vaccines are needed to control T. pisiformis infections.

Purpose of the Study:

• To evaluate the efficacy of Taenia pisiformis oncosphere (TpO) and metacestode (TpMcES) antigens formulated with liposomes or Freund's Incomplete Adjuvant (FIA) in protecting rabbits against infection.
• To compare the immune responses elicited by different antigen formulations.

Main Methods:

• Rabbits were vaccinated with TpO or TpMcES, formulated with liposomes or FIA.
• Vaccinated rabbits were challenged with T. pisiformis eggs.
• Peritoneal cyst burdens and metacestode viability were assessed post-challenge.
• Specific antibody responses (IgG) were measured.

Main Results:

• Vaccination with TpO, particularly when mixed with liposomes (86% reduction), significantly reduced peritoneal cyst numbers compared to controls.
• TpO formulated with liposomes (75% reduction) or FIA (67% reduction) showed protective effects.
• TpMcES formulations provided lower cyst reduction (32-39%) but induced high metacestode mortality (>85%).
• Humoral immune responses (IgG) were similar between liposome and FIA formulations.

Conclusions:

• Liposome-based vaccines containing TpO antigens offer significant protection against Taenia pisiformis infection in rabbits.
• Different antigen preparations (TpO vs. TpMcES) may elicit distinct immune responses and protection mechanisms.
• Liposomes represent a promising adjuvant and delivery system for veterinary vaccines against parasitic infections.