Atopic dermatitis (AD) is a chronic inflammatory skin disease with repeated exacerbations of eczema and pruritus. Probiotics
can prevent or treat AD appropriately via modulation of immune responses and gut microbiota. In this study, we evaluated
effects of Lactobacillus acidophilus (L. acidophilus) KBL409 using a house dust mite (Dermatophagoides farinae)-induced
in vivo AD model. Oral administration of L. acidophilus KBL409 significantly reduced dermatitis scores and decreased
infiltration of immune cells in skin tissues. L. acidophilus KBL409 reduced in serum immunoglobulin E and mRNA levels
of T helper (Th)1 (Interferon-γ), Th2 (Interleukin [IL]-4, IL-5, IL-13, and IL-31), and Th17 (IL-17A) cytokines in skin tissues.
The anti-inflammatory cytokine IL-10 was increased and Foxp3 expression was up-regulated in AD-induced mice with
L. acidophilus KBL409. Furthermore, L. acidophilus KBL409 significantly modulated gut microbiota and concentrations
of short-chain fatty acids and amino acids, which could explain its effects on AD. Our results suggest that L. acidophilus
KBL409 is the potential probiotic for AD treatment by modulating of immune responses and gut microbiota of host.
Salmonella enterica is a major human pathogen that causes
invasive non-typhoidal Salmonellosis (iNTS), resulting in
significant morbidity and mortality. Although a number of
pre-clinical and clinical studies have reported on the feasibility
of developing a safe and effective vaccine against iNTS,
there have been no licensed Salmonella vaccines available to
protect against NTS strains. Vaccine formulations of highest
priority for NTS are live attenuated vaccines, which can elicit
effective induction of intestinal mucosal and intracellular
bacteria-specific cell mediated immune responses. Since glucose
is crucial for intracellular survival and replication in
host cells, we constructed strains with mutations in components
of the glucose uptake system, called the phosphotransferase
system (PTS), and compared the relative virulence and
immune responses in mice. In this study, we found that the
strain with mutations in both ptsI and crr (KST0556) was the
most attenuated strain among the tested strains, and proved
to be highly effective in inducing a mucosal immune response
that can protect against NTS infections in mice. Thus, we suggest
here that KST0556 (ΔptsIΔcrr) is a potential live vaccine
candidate for NTS, and may also be a candidate for a live delivery
vector for heterologous antigens. Moreover, since PTS
is a well-conserved glucose transporter system in both Gramnegative
and Gram-positive bacteria, the ptsI and crr genes
may be potential targets for creating live bacterial vectors or
vaccine strains.