Distribution of the <i>bab</i> genotypes in AH and KH (n = 160).

<p>Genotypes of one, two, three, or none <i>bab</i> genes are grouped into I, II, III, and IV, respectively. These classifications were made on the basis of number of <i>bab</i> genes present at locus A, B, and C. A black, white, or grey box indicated <i>babA</i>, <i>babB</i>, and <i>babC</i>, respectively. ‘-’ indicates the absence of <i>bab</i> gene at the designated loci. ‘AH%’ and ‘KH%’ indicate the frequency of each individual genotype within the specified population (n = 80) and ‘Total%’ shows the percent of the respective genotype in the overall population (n = 160). Bracketed numbers indicate the number of isolates possessing each respective genotype out of the population examined. ‘_*’ indicates genotypes containing chimeric form(s).</p

<i>Helicobacter pylori bab</i> Paralog Distribution and Association with <i>cagA</i>, <i>vacA</i>, and <i>homA/B</i> Genotypes in American and South Korean Clinical Isolates

<div><p><i>Helicobacter pylori</i> genetic variation is a crucial component of colonization and persistence within the inhospitable niche of the gastric mucosa. As such, numerous <i>H</i>. <i>pylori</i> genes have been shown to vary in terms of presence and genomic location within this pathogen. Among the variable factors, the Bab family of outer membrane proteins (OMPs) has been shown to differ within subsets of strains. To better understand genetic variation among the <i>bab</i> genes and to determine whether this variation differed among isolates obtained from different geographic locations, we characterized the distribution of the Bab family members in 80 American <i>H</i>. <i>pylori</i> clinical isolates (AH) and 80 South Korean <i>H</i>. <i>pylori</i> clinical isolates (KH). Overall, we identified 23 different <i>bab</i> genotypes (19 in AH and 11 in KH), but only 5 occurred in greater than 5 isolates. Regardless of strain origin, a strain in which locus A and locus B were both occupied by a <i>bab</i> gene was the most common (85%); locus C was only occupied in those isolates that carried <i>bab</i> paralog at locus A and B. While the <i>babA</i>/<i>babB</i>/- genotype predominated in the KH (78.8%), no single genotype could account for greater than 40% in the AH collection. In addition to basic genotyping, we also identified associations between <i>bab</i> genotype and well known virulence factors <i>cagA</i> and <i>vacA</i>. Specifically, significant associations between <i>babA</i> at locus A and the <i>cagA</i> EPIYA-ABD motif (<i>P</i><0.0001) and the <i>vacA</i> s1/i1/m1 allele (<i>P</i><0.0001) were identified. Log-linear modeling further revealed a three-way association between <i>bab</i> carried at locus A, <i>vacA</i>, and number of OMPs from the HOM family (<i>P</i><0.002). <i>En masse</i> this study provides a detailed characterization of the <i>bab</i> genotypes from two distinct populations. Our analysis suggests greater variability in the AH, perhaps due to adaptation to a more diverse host population. Furthermore, when considering the presence or absence of both the <i>bab</i> and <i>homA/B</i> paralogs at their given loci and the <i>vacA</i> genotype, an association was observed. Our results highlight the multifactorial nature of <i>H</i>. <i>pylori</i> mediated disease and the importance of considering how the specific combinations of <i>H</i>. <i>pylori</i> virulence genes and their multiple interactions with the host will collectively impact disease progression.</p></div

Outline of <i>bab</i> genotyping by PCR.

<p>(Top) Schematic representation of the three loci where the <i>bab</i> genes are generally detected: Locus A, B and C. The annealing positions (arrows) and names of each locus-specific forward are shown. (Bottom) Annealing positions (arrows) and names of <i>bab</i>-specific reverse primer are indicated with their respective <i>bab</i> gene: <i>babA</i> depicted by the black box, <i>babB</i> depicted by the white box, <i>babC</i> depicted by the grey box. Primers are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137078#pone.0137078.t001" target="_blank">Table 1</a>, and a full explanation of the genotyping scheme can be found in the Materials and Methods.</p

Schematic comparison of BabA, BabB, and BabC.

<p>The representative structures of BabA and BabB are based on the J99 amino acid sequence, whereas the structure of BabC is based on the consensus sequence defined in this study. The N-HR indicates N-terminal homology region, M-VR indicates middle variable region, which is characterized by sequence difference among the three Bab proteins. Note that the M-VR is conserved for each of the Bab proteins. The C-HR indicates C-terminal homologous region that shows >90% identity. The CT-R present at the N-terminus of BabB refers to the CT repeat region. VR-1 and VR-2 in BabC indicate regions of variability among the BabC amino acid sequences analyzed in this study (n = 15).</p

Correction: <i>Helicobacter pylori bab</i> Paralog Distribution and Association with <i>cagA</i>, <i>vacA</i>, and <i>homA/B</i> Genotypes in American and South Korean Clinical Isolates

Correction: <i>Helicobacter pylori bab</i> Paralog Distribution and Association with <i>cagA</i>, <i>vacA</i>, and <i>homA/B</i> Genotypes in American and South Korean Clinical Isolate

Primer sequences for analysis of <i>H</i>. <i>pylori bab</i> genes.

<p>^<i>a</i> One nucleotide in the primer was modified from the indicated primer in reference.</p><p>^<i>b</i> Primer was used for sequencing.</p><p>^<i>c</i> Underlined Y indicates C or T, and underlined R indicates G or A.</p><p>^<i>d</i> Primer name was used in the indicated reference.</p><p>Primer sequences for analysis of <i>H</i>. <i>pylori bab</i> genes.</p

Cell Therapy with Embryonic Stem Cell-Derived Cardiomyocytes Encapsulated in Injectable Nanomatrix Gel Enhances Cell Engraftment and Promotes Cardiac Repair

A significant barrier to the therapeutic use of stem cells is poor cell retention <i>in vivo</i>. Here, we evaluate the therapeutic potential and long-term engraftment of cardiomyocytes (CMs) derived from mouse embryonic stem cells (mESCs) encapsulated in an injectable nanomatrix gel consisting of peptide amphiphiles incorporating cell adhesive ligand Arg-Gly-Asp-Ser (PA-RGDS) in experimental myocardial infarction (MI). We cultured rat neonatal CMs in PA-RGDS for 7 days and found that more than 90% of the CMs survived. Next, we intramyocardially injected mouse CM cell line HL-1 CMs with or without PA-RGDS into uninjured hearts. Histologic examination and flow cytometry analysis of digested heart tissues showed approximately 3-fold higher engraftment in the mice that received CMs with PA-RGDS compared to those without PA-RGDS. We further investigated the therapeutic effects and long-term engraftment of mESC-CMs with PA-RGDS on MI in comparison with PBS control, CM-only, and PA-RGDS only. Echocardiography demonstrated that the CM-only and CM+PA-RGDS groups showed higher cardiac function at week 2 compared to other groups. However, from 3 weeks, higher cardiac function was maintained only in the CM+PA-RGDS group; this was sustained for 12 weeks. Confocal microscopic examination of the cardiac tissues harvested at 14 weeks demonstrated sustained engraftment and integration of mESC-CMs into host myocardium in the CM+PA-RGDS group only. This study for the first time demonstrated that PA-RGDS encapsulation can enhance survival of mESC-derived CMs and improve cardiac function post-MI. This nanomatrix gel-mediated stem cell therapy can be a promising option for treating MI