Lactobacillus pentosus expressing porcine lactoferrin elevates antibacterial activity and improves the efficacy of vaccination against Aujeszky’s disease

Abstract

In this study, Lactobacillus pentosus expressing porcine lactoferrin (pLF) was tested for in vitro antibacterial activity and for its ability to enhance immunity induced by an orally administered Aujeszky's disease virus (ADV) vaccine. The cDNA encoding N-terminus of pLF was cloned into a Lactobacillus-specific plasmid to produce L. pentosus pLF expressing transformants (pPG612.1-pLF-N/L. pentosus). The antimicrobial activity of the recombinant pLF protein inhibited bacterial growth in vitro. The supernatant of pPG612.1-pLF-N/L. pentosus had an inhibitory effect on Staphylococcus aureus strain CVCC26003, Bacillus subtilis strain CVCC63501, Escherichia coli strain CVCC10141 and Salmonella enterica ssp. enterica Choleraesuis strain CVCC79102, while it did not inhibit the growth of Lactobacillus casei strain ATCC393. A mouse model was established to test the effectiveness of the orally administered probiotic L. pentosus recombinant strain in the gastrointestinal tract. Mice were immunised with an attenuated porcine Aujeszky's disease virus (ADV) vaccine. Serum antibody levels determined using a mouse Aujeszky's disease IgG ELISA showed that IgG levels were significantly higher in the pPG612.1-pLF N /L. pentosus group than in the PBS and Lactobacillus pentosus groups at days 7 and 21 (P < 0.01) and at day 14 (P < 0.05), indicating that this oral recombinant strain can improve the effectiveness of the vaccine and play a role in immune enhancement through humoral immunity. These results suggest that the recombinant Lactobacillus pentosus not only has the beneficial characteristics of lactic acid bacteria but also produces biologically functional lactoferrin.Key words: Porcine lactoferrin, recombinant Lactobacillus pentosus, antibacterial activity, immune enhancement Lactoferrin (LF) is an 80-kDa iron-binding glycoprotein. It is abundantly found in exocrine secretions of mammals and especially in milk and fluids of the digestive tract released by mucosal epithelia and neutrophils during inflamma-

The Impact of Lactoferrin on the Growth of Intestinal Inhabitant Bacteria

“…Lfcin-Lfampin could be used as a replacement for antibiotic therapy for sepsis, taking advantage of its selective antimicrobial action and probiotic effect as an immune modulator [115,117]. Recombinant Lactobacillus strains expressing Lf [126,127] may be future strategies to prevent and combat high-risk human infections, such as neonatal necrotizing enterocolitis [128]. As documented in murine models and clinical trials, pharmaceutical preparations containing bLf and probiotics or Lf-producing probiotic strains have been effective to combat vulvovaginal infections caused Candida albicans , Gardnerella vaginalis, or Atopobium vaginalis by restoring the microbiota in vulvovaginal tract [129,130,131].…”

A Single Plasmid of Nisin-Controlled Bovine and Human Lactoferrin Expressing Elevated Antibacterial Activity of Lactoferrin-Resistant Probiotic Strains

“…In addition, Lactobacillus pentosus has been used to express porcine LF (PLF), and L. pentosus/PLF supplementation has been described to elevate antibacterial activity and improve the efficacy of vaccination against Aujeszky's disease in a mouse model. This report also suggests that recombinant L. pentosus could provide both the beneficial characteristics of lactic acid bacteria and the biological activity of lactoferrin [14]. Finally, L. plantarum has been employed for expression of PLF and was used as a feed additive in the daily diet of weaned piglets, and addition of recombinant L. plantarum/PLF led to a significant increase in average daily gain and feed intake, improved feed efficiency, and reduced incidence of diarrhea in these piglets [15].…”

Featured Prebiotic Agent: The Roles and Mechanisms of Direct and Indirect Prebiotic Activities of Lactoferrin and Its Application in Disease Control

“…Similarly, Liao et al developed a BLF-expressing L. casei strain and found that the recombinant L. casei /pPG612.1-BLF acted as an enhancer, improving the immunity of vaginal mucosa against the intrusion of Candida albicans in a murine model [ 104 ]. Moreover, L. pentosus was engineered to express PLF, and this recombinant PLF-expressing probiotic strain was demonstrated to increase the antibacterial activity in vitro and improve the efficacy of vaccination against Aujeszky’s disease in a mouse model [ 105 ].…”