# Immunological Effects of Protoscolex Antigen Injection on Hydatid Cyst Development in Mice

## TL;DR

Injecting Protoscolex antigen in mice boosts immune responses and reduces hydatid cyst development, suggesting potential for a vaccine.

## Contribution

Demonstrates Protoscolex antigen's immune-activating potential and efficacy in reducing hydatid disease severity in mice.

## Key findings

- Antibody levels (IgA, IgG, IgM) were significantly higher in the treatment group compared to the control.
- Complement proteins C3 and C4 showed significant differences in the treatment group.
- PMN activity, including NBT reduction and phagocytosis, was enhanced, and infection levels decreased by 50.4%.

## Abstract

Hydatid disease is a widespread disease that affects all human organs.

This study aimed to evaluate antibodies (IgA, IgG, and IgM), complement proteins (C3 and C4), MIF of PMNs cells, reduction of nitro blue tetrazolium (NBT), and phagocytic activity against
Candida albicans.

Hydatid cysts were collected from surgically injured patients at Fallujah Teaching Hospital, Twenty BALB/c mice were injected with Protoscolex antigen as treatment groups or phosphate-buffered saline (PBS) as control groups, at booster and challenge doses. Antibodies and complement concentrations were measured by enzyme-linked immunosorbent assay (ELISA), and the MIF of PMNs cells, reduction of NBT, and phagocytic activity against
Candida albicans were measured to assess cellular activity.

The results showed significant differences in the levels of antibodies compared to the control group 21 days after injection of the protoscolex antigen at a concentration of 0.5 ml subcutaneously. There were also significant differences between the treatment and control group in the levels of C3 and C4. NBT dye reduction and phagocytosis of
Candida albicans by PMNs showed significant differences compared to the control group. The results also showed a significant decrease in PMN viability in the treatment group. An increase in neutrophil migration diameter was observed. The results showed a 50.4% decrease in the infection level in the treatments injected with the antigen, and the average diameter of the hydatid cysts decreased compared with the control group.

The results indicate that Protoscolex antigen activates the immune response and reduces severity of hydatid disease. This highlights its potential as a promising candidate for developing a vaccine or preventive strategy against hydatid disease.