Immune Responses Induced by Recombinant Membrane Proteins of Mycoplasma agalactiae in Goats

TL;DR

This study tests recombinant proteins from Mycoplasma agalactiae as a potential vaccine in goats, showing they can trigger immune responses.

Contribution

The study introduces recombinant membrane proteins as a novel subunit vaccine candidate for Mycoplasma agalactiae in goats.

Findings

Recombinant proteins P40 and MAG_1560 induced a six-month antibody response in goats.

Cytokine gene expression, including IL-1β and MHC-II, was stimulated by the recombinant proteins.

The proteins elicited both humoral and cellular immune responses, supporting their vaccine potential.

Abstract

Background/Objectives: Contagious agalactia (CA) is a disease typically caused by Mycoplasma agalactiae, affecting small ruminants worldwide and being endemic in certain countries. CA causes severe economic losses due to mastitis, agalactia, and arthritis. As an alternative to existing immunoprophylactic measures, this study aimed to develop a recombinant subunit vaccine against M. agalactiae and evaluate its specific immune response in goats. Methods: Goats were divided into three groups: group 1 received recombinant proteins (P40 and MAG_1560), group 2 received formalin-inactivated M. agalactiae, and group 3 received Tris-buffered saline (negative control). All solutions were emulsified in Freund’s adjuvant. Animals were monitored for 181 days. IgG antibody production was assessed by ELISA, and peripheral blood mononuclear cells (PBMCs) were analyzed by real-time PCR for the expression of IL-1β, IFN-γ, IL-12, and MHC class II genes. Results: M. agalactiae-specific antibody response was observed for six months in the sera of animals from group 1. Analysis of cytokine gene expression revealed increased IL-1β mRNA levels over time in both experimental groups. In group 1, IFN-γ mRNA levels increased with P40 stimulation and decreased with MAG_1560. IL-12 mRNA expression decreased over time in group 1 with P40 stimulation, whereas group 2 showed increased IL-12 expression for both proteins. MHC-II expression was stimulated in both groups. Conclusions: The recombinant proteins induced antibody production and cytokine expression, demonstrating immunogenic potential and supporting their promise as vaccine candidates capable of eliciting both humoral and cellular immune responses against M. agalactiae.

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