Generation of epidermal growth factor and green fluorescent protein coexpressing Lactobacillus acidophilus and its effect on intestinal histology improvement in mature LPS-challenged mice

Abstract

The aim of the present study was to construct a recombinant strain by using the probiotics Lactobacillus
acidophilus expressing the epidermal growth factor (EGF), which can improve intestinal morphology, and to test its
effect on the intestinal histology in LPS (lipopolysaccharide)-challenged mice. The EGF gene was cloned into the shuttle
vector pSET4s and then transformed into the L. acidophilus MG6243 strain by electroporation. Two recombinant strains
were confirmed by SDS-PAGE and named ΔMG6243-1 and ΔMG6243-2. Sixty mice were randomly assigned to six
treatments: 1) non-challenged control, 2) LPS-challenged control, 3) LPS-challenged + 200 μl MG6243, 4) LPSchallenged + 200 μl ΔMG6243-1, 5) LPS-challenged + 200 μl ΔMG6243-1 + inducer IPTG, and 6) LPS-challenged + 200
μl ΔMG6243-2. There were ten replicates for each treatment, and each replicate had one mouse. On d 15, the LPSchallenged mice were injected intraperitoneally with LPS at 10 mg/kg BW, while the non-challenged mice were injected
with 0.9% NaCl solution. Three hours after the challenge, all mice were killed. Results showed that both ΔMG6243-1
and ΔMG6243-2 could increase villus height in the duodenum, ileum and jejunum (P<0.05). In addition, the
recombinant L. acidophilus decreased the crypt depth in the duodenum and ileum (P<0.05). These results indicated that
the recombinant L. acidophilus could effectively improve the intestinal histology in LPS-challenged mice.