Characterization of two lipoproteins in Pasteurella multocida

Area of Science:

• Bacteriology
• Immunology
• Molecular Biology

Background:

• In vivo expression technology (IVET) identified Pasteurella multocida genes upregulated during host infection.
• Two identified genes encode proteins similar to Haemophilus influenzae lipoproteins (Protein D and PCP), known to induce heterologous immunity.
• This study focuses on Pasteurella multocida GlpQ and PCP lipoprotein homologues.

Purpose of the Study:

• To investigate the P. multocida GlpQ and PCP homologues as potential vaccine candidates.
• To determine if these lipoproteins can induce protective immunity against P. multocida infection.

Main Methods:

• Confirmed GlpQ and PCP as lipoproteins using globomycin inhibition of post-translational processing.
• Assessed GlpQ enzyme activity and confirmed its functional homology.
• Determined surface exposure of PCP and GlpQ using surface immunoprecipitation.
• Vaccinated mice and chickens with both non-lipidated and lipidated forms of GlpQ and PCP expressed in E. coli.

Main Results:

• GlpQ exhibited glycerophosphodiester phosphodiesterase activity, confirming it as a functional homologue.
• PCP was found to be surface-exposed, while GlpQ was not.
• Vaccination with non-lipidated or lipidated GlpQ and PCP did not confer protection against P. multocida challenge in mice or chickens.

Conclusions:

• While GlpQ and PCP are confirmed lipoproteins and PCP is surface-exposed, they do not induce protective immunity against P. multocida in the tested models.
• Further research is needed to identify effective vaccine targets against P. multocida.