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Antimicrobial peptides are crucial for host defense at mucosal surfaces. Bacterial factors responsible for induction of human ␤-defensin-2 (hBD-2) mRNA expression in Caco-2 human carcinoma cells were determined. Salmonella enteritidis, Salmonella typhimurium, Salmonella typhi, Salmonella dublin, and culture supernatants of these strains induced hBD-2 mRNA expression in Caco-2 human carcinoma cells. Using luciferase as a reporter gene for a ϳ2.1-kilobase pair hBD-2 promoter, the hBD-2-inducing factor in culture supernatant of S. enteritidis was isolated. The supernatant factor was heat-stable and proteinase-sensitive. After purification by anion exchange and gel filtration chromatography, the hBD-2-inducing factor was identified as a 53-kDa monomeric protein with the amino-terminal sequence AQVINTNSLSLLTQNNLNK, which is identical to that of the flagella filament structural protein (FliC) of S. enteritidis. Consistent with this finding, the 53-kDa protein reacted with anti-FliC antibody, which prevented its induction of hBD-2 mRNA in Caco-2 cells. In agreement, the hBD-2-inducing activity in culture supernatant was completely neutralized by anti-FliC antibody. In gel retardation analyses, FliC increased binding of NF-B (p65 homodimer) to hBD-2 gene promoter sequences. We conclude that S. enteritidis FliC induces hBD-2 expression in Caco-2 cells via NF-B activation and thus plays an important role in up-regulation of the innate immune response.Antimicrobial peptides play an important role in host defense at mucosal surfaces. The two major groups of vertebrate defensins, ␣-and ␤-defensins, differ in the arrangements of their disulfide bonds. Six human ␣-defensins (HD-1 to HD-6) 1 and two ␤-defensins (hBD-1 and hBD-2) have been reported to date. HD-1, HD-2, HD-3, and HD-4 are present in neutrophils, where they constitute 30 -50% of the total protein in azurophilic granules (1). HD-5 and HD-6 were identified in the Paneth cells of small intestinal crypts (2, 3) and in female reproductive tissue (4). hBD-1 was purified from plasma (5) and detected in a range of epithelial tissues (6). hBD-2 was purified from skin and shown to be expressed in the lung and uterus (7). hBD-2 was induced in mucosal tissues following bacterial infections (7-9).Salmonella species are Gram-negative organisms that cause gastroenteritis and enteric fever in humans. As pointed out by Bä umler et al. (10), an increase in numbers of human infections with Salmonella enteritidis began in the 1960s but was followed by an almost 50% decrease from 1970 to 1976. Another increase began in 1977, with signs of a decrease beginning in 1992. In contrast, the increasing frequency of S. enteritidis infection in poultry did not begin until 1989, and a decline started in 1996 (11). Reasons for the fluctuations are unknown, but the recent recognition of food-borne infection with S. enteritidis has renewed interest in how these organisms can invade, persist, and spread.To evaluate the role of defensins in S. enteritidis infection, we investigated the induction of ...

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To determine the mechanism involved, the incorporation rate (ICR) of drugs into hair was compared to melanin affinity, lipophilicity and membrane permeability. The following 20 drugs were tested; amphetamine, methamphetamine, p-hydroxyamphetamine, p-hydroxymethamphetamine, cocaine, benzoylecgonine, ecgonine methyl ester, morphine, 6-acetylmorphine, phencyclidine, 1-(1-phenyl)-piperidinyl-cyclohexanol, methylenedioxyamphetamine, methylenedioxymethamphetamine, methoxyphenamine, O-desmethyl methoxyphenamine, benzphetamine, norbenzphetamine, deprenyl, lysergic acid diethylamide (LSD) and 11-nortetrahydrocannabinol-9-carboxylic acid (THCA). Their ICRs were represented as the ratios of the drug concentrations in rat hair to AUCs (the areas under the concentration vs. time curves) in rat plasma. Cocaine had the highest incorporation rate understood and there was a 3600 fold difference between the ICR of cocaine and that of THCA, the lowest drug. The melanin affinity of these drugs was determined by incubating a test solution with melanin at 36 degrees C in the dark for 2 h. After incubation and centrifugation, the drug concentration in the filtrate was determined by GC/MS or LC. The drug most affinitive to melanin was cocaine, followed by benzphetamine, phencyclidine, methylenedioxymethamphetamine and LSD. The correlation coefficient between ICR and melanin affinity of the 20 drugs was 0.947 (0.949 excluding THCA). Lipophilicity was calculated from the retention times of HPLC according to Kaliszan's method. Although the correlation coefficient between ICR and lipophilicity was very low (0.201), it rose to 0.770 by removing only THCA. The combination of melanin affinity and lipophilicity brought about a higher correlation (0.979) with the ICRs. Our data also suggested that the higher ICRs of basic drugs than neutral or acidic ones are strongly related to the membrane permeability of the drug based on the pH gradient between blood (pH 7.4) and hair matrix (acidic).