# Dose-Dependent Prophylactic Efficacy of Filarial Antigens Glutathione-S-Transferase and Abundant Larval Transcript-2 against Brugia malayi Challenge in Mastomys

## TL;DR

This study tests how well different doses of two filarial antigens protect Mastomys against Brugia malayi infection, finding that a specific dose of one antigen with an adjuvant provides strong protection.

## Contribution

The study identifies the optimal dose of rBmALT-2 combined with alum for maximal prophylactic efficacy against B. malayi infection in Mastomys.

## Key findings

- A 50 μg dose of rBmALT-2 with alum induced 79–81% killing of L3 larvae in vivo and in vitro.
- The combination of rBmALT-2 and rWbGST with alum induced 63–68% larval killing.
- Vaccinated Mastomys showed elevated IL-10, IL-4, and IFN-γ levels, indicating Th1 and Th2 immune responses.

## Abstract

To identify the most effective dose of filarial rBmALT-2 and rWbGST alone or in combination against B. malayi infection in vitro and in vivo.

Mastomys (n = 5–7/group) received intramuscular (i.m.) injection with three different doses (25, 50, and 100 μg) of rBmALT-2 or rWbGST, either alone or in combination with alum as the adjuvant. Protective immunity was studied by in vivo and in vitro cytotoxicity assay. To evaluate the cellular immune response, splenocyte proliferation and cytokine profile were assessed.

Serological results revealed a substantial (p < 0.005) induction of IgG1, IgG2a, and IgG3 responses in vaccinated Mastomys. Mastomys immunized with 50 μg rBmALT-2 + alum induced 79–81% killing against the L3 larvae challenge in vivo and in vitro ADCC assay (p < 0.005); whereas rWbGST + alum alone or in combination with rBmALT-2 + alum induced 63–68% killing (p < 0.005) in vivo and in vitro. Antigen-specific cytokine profiles of Mastomys vaccinated with either BmALT-2, WbGST or a combination showed elevated IL-10, IL-4, and IFN-γ levels, signifying both Th1 and Th2 immune response.

These findings suggest that immunization of Mastomys with a 50 μg/dose of rBmALT-2 + alum four times at a 4-week interval demonstrated considerable protection against B. malayi infection.