This report has been corrected. The definition of pediatric obesity was incorrectly stated in the text of the report and in the Table footnote; however, the analysis was correct and used the CDC definition of pediatric obesity for children aged ≥2 years (body mass index [kg/m2] ≥95th percentile for age and sex based on CDC growth charts).

No abstract

The p53 protein is a pivotal tumor suppressor that is frequently mutated in many human cancers, although precisely how p53 prevents tumors is still unclear. To add to its complexity, several isoforms of human p53 have now been reported. The ⌬133p53 isoform is generated from an alternative transcription initiation site in intron 4 of the p53 gene (Tp53) and lacks the N-terminus. Elevated levels of ⌬133p53 have been observed in a variety of tumors. To explore the functions of ⌬133p53, we created a mouse expressing an N-terminal deletion mutant of p53 (⌬122p53) that corresponds to ⌬133p53. ⌬122p53 mice show decreased survival and a different and more aggressive tumor spectrum compared with p53 null mice, implying that ⌬122p53 is a dominant oncogene. Consistent with this, ⌬122p53 also confers a marked proliferative advantage on cells and reduced apoptosis. In addition to tumor development, ⌬122p53 mice show a profound proinflammatory phenotype having increased serum concentrations of interleukin-6 and other proinflammatory cytokines and lymphocyte aggregates in the lung and liver as well as other pathologies. Based on these observations, we propose that human ⌬133p53 also functions to promote cell proliferation and inflammation, one or both of which contribute to tumor development. (Blood. 2011;117(19): 5166-5177) Introduction p53 is most important for preventing cancers. We know this because mice deleted for the p53 gene (Trp53) are highly tumor prone 1 ; in humans, Li-Fraumeni syndrome, characterized by multiple tumor phenotypes, is the result of germline inherited mutations in the p53 gene (Tp53) 2 ; and most common human cancers contain mutations in Tp53 (www.p53.iarc.fr), generally rendering the protein functionally impaired. Ten isoforms of human p53 have been reported that are generated by the use of alternative translation initiation sites, splicing, or alternative promoters. [3][4][5][6][7][8][9] Two p53 isoforms (⌬40p53 and ⌬133p53) lack the N-terminus of p53, whereas 4 others (⌬40p53␤, ⌬40p53␥, ⌬133p53␤, and ⌬133p53␥) also lack part of the C-terminus beyond codon 331. In addition, 3 more isoforms have recently been described (⌬160p53, ⌬160p53␤, ⌬160p53␥) that use an alternative start codon at position 161 in the transcript for the ⌬133p53 isoform family. 8 The isoforms are generally expressed in a variable and to some extent tissue specific manner, although the ⌬133p53 isoform appears to be ubiquitous. 5 Aberrant expression of the ⌬133p53 isoforms occurs in a variety of tumors, including breast, 5 head and neck, 10 acute myeloid leukemia, 11 melanoma, 12 colon cancer, 13 and ovarian cancer, 14 suggesting that ⌬133p53 contributes to tumor formation. In zebrafish, the homolog of ⌬133p53 (⌬113p53) attenuates p53-dependent apoptosis by activating the homolog (bcl2l) of the antiapoptotic protein Bcl-xl, 15 and knockdown of ⌬113p53 using silencing RNA induced p53-dependent apoptosis. In another study, overexpression of ⌬133p53 extended the life span of normal human fibroblasts by inhibiting replicative senescen...

The motility genes mot4 and motE of Escherichua coil were placed under control of the Serrala marcescens trp promoter. After induction with 0-indoleacrylic acid, the levels of MotA and MotB rose over about a 3-h period, reaching plateau levels approximately 50-fold higher than wild-type levels. Both overproduced proteins inserted into the cytoplasmic membrane. Growth and motility were essentially normal, suting that although the motor is a proton-conducting device, MotA and MotB together do not constitute a major proton leak. Derivative plasmids which maintained an intact version of motB but had the motA coding region deleted in various ways were constructed. With these, the levels of MotB were much lower, reaching a peak within 30 min after induction and ding thereafter; pulse-chase measurements indicated that a contributing factor was MotB degradation. The low levels of MotB occurred even with an in-frame internal deletion of mot4, whose translational initiation and termination sites were proteins (8,21) indicate that MotA is quite hydrophobic (with at least four predicted membrane-spanning regions) but MotB is less so (with one strongly predicted membranespanning region); protease-sensitivity and phoA-fusion experiments (7) confirm that MotB spans the membrane once, with the N terminus in the cytoplasm and the bulk of the protein residing in the periplasm.Even when overproduced at levels 50-fold over normal and in the absence of MotB, MotA is membrane associated (22). MotB, however, has been reported to remain in the cytoplasm when it alone is overproduced (21), suggesting that it may require MotA or other flagellar components for insertion into the membrane in appreciable amounts.We were therefore interested to know whether increasing the levels of both MotA and MotB would alter the situation. In addition to the issue of stabilization of MotB in the membrane, we were also interested in possible interaction of the motA and motB genes at the translational level, since they are adjacent within the mocha operon, with a four-base overlap (ATGA) of their coding regions.We report here an analysis of plasmids with motA and motB in their normal relationship with each other, but under an inducible promoter, and also of plasmids with motB intact but with in-frame and out-of-frame fusions and internal deletions of motA. Under all circumstances, MotB was found in the membrane fraction. However, its stable existence was dependent on the presence of MotA. MATERMILS AND METHODSBacterial strains, plasmids, media, enzymes, and chemicals. The strains and plasmids used are listed in Table 1. Growth conditions, including those for overproduction of proteins whose genes are under control of the Serratia marcescens trp promoter, have been described (22). Enzymes and chem-

Lactobacillus reuteri 100-23 is a bacterial commensal of the gastrointestinal tract of mice. Previous studies have shown that colonization of the murine gut by this strain stimulates small-bowel enterocytes to produce proinflammatory cytokines. This is associated with a mild, transitory inflammatory response 6 days after inoculation of formerly Lactobacillus-free animals. The inflammation subsides by 21 days after colonization, although lactobacilli continue to be present in the bowel. To determine the immunological mechanisms that underpin tolerance to bowel commensals, we investigated cytokine responses of dendritic cells The digestive tracts of mammals contain biodiverse bacterial communities, the members of which are referred to as commensals. 1 The forestomach of the gastric region of mice is lined with a keratinized, stratified squamous epithelium, and commensal lactobacilli, such as Lactobacillus reuteri strain 100-23, attach directly to this epithelium. They proliferate to form a layer (biofilm) of cells, and as they are carried on squames into the digesta, they can be detected in substantial numbers throughout the remainder of the digestive tract. 2 A unique mouse colony has been developed, which, unlike conventional mice, does not harbor lactobacilli as commensals of the digestive tract. 3 Although Lactobacillus free, the mice harbor a biodiverse bacterial community in the large bowel. The mucosa is therefore conditioned by exposure to bacteria, characteristic of the murine bowel biome, but is naive with respect to the influences of lactobacilli. These mice provide a defined system by which the impact of lactobacilli on the host immune response can be studied.Oral administration of L. reuteri 100-23 cells to adult Lactobacillusfree mice results in colonization of the forestomach by lactobacilli and a mild inflammatory response in the ileal mucosa 6 days after inoculation. 4 Transcription of genes encoding interleukin (IL)-1a and IL-6 is increased in small-bowel enterocytes at this time. This coincides with the development of a maximal population of lactobacilli in the ileum. Although the numbers of lactobacilli remain at this same constant level throughout the remainder of the animal's life, inflammation is transient and resolves by 21 days after inoculation, at which time the IL gene expression of enterocytes returns to baseline. 4 It seems, therefore, that the innate immune response to the presence of L. reuteri 100-23 is downregulated with time, but by an as yet unknown mechanism. Antibodies that react with a large protein on the surface of L. reuteri 100-23 cells, indicative of an adaptive immune response, are present in sera of mice that have been colonized by the bacteria, but not in the sera of noncolonized mice (GW Tannock, unpublished). Overall, however, bowel commensals do not invoke an immune response of pathological consequences under normal circumstances. The mechanisms by which this is achieved are largely unknown. Thus, we used the L. reuteri 100-23/Lactobacillus-free mouse paradigm to...