Multiple sialic acid (SA) residues conjugated to a linear polyacrylamide backbone are more effective than monomeric SA at inhibiting influenza-induced agglutination of red blood cells. However, "polymeric inhibitors" based on polyacrylamide backbones are cytotoxic. Dendritic polymers offer a nontoxic alternative to polyacrylamide and may provide a variety of potential synthetic inhibitors of influenza virus adhesion due to the wide range of available polymer structures. We evaluated several dendritic polymeric inhibitors, including spheroidal, linear, linear-dendron copolymers, comb-branched, and dendrigraft polymers, for the ability to inhibit virus hemagglutination (HA) and to block infection of mammalian cells in vitro. Four viruses were tested: influenza A H2N2 (selectively propagated two ways), X-31 influenza A H3N2, and sendai. The most potent of the linear and spheroidal inhibitors were 32-256-fold more effective than monomeric SA at inhibiting HA by the H2N2 influenza virus. Linear-dendron copolymers were 1025-8200-fold more effective against H2N2 influenza, X-31 influenza, and sendai viruses. The most effective were the comb-branched and dendrigraft inhibitors, which showed up to 50000-fold increased activity against these viruses. We were able to demonstrate significant (p < 0.001) dose-dependent reduction of influenza infection in mammalian cells by polymeric inhibitors, the first such demonstration for multivalent SA inhibitors. Effective dendrimer polymers were not cytotoxic to mammalian cells at therapeutic levels. Of additional interest, variation in the inhibitory effect was observed with different viruses, suggesting possible differences due to specific growth conditions of virus. SA-conjugated dendritic polymers may provide a new therapeutic modality for viruses that employ SA as their target receptor.

Two nontoxic, antimicrobial nanoemulsions, BCTP and BCTP 401, have been developed. These emulsions are composed of detergents and oils in 80% water. BCTP diluted up to 1:1000 inactivated>90% of Bacillus anthracis spores in 4 h and was also sporicidal against three other Bacillus species. This sporicidal activity is due to disruption of the spore coat after initiation of germination without complete outgrowth. BCTP 401 diluted 1:1000 had greater activity than BCTP against Bacillus spores and had an onset of action of <30 min. Mixing BCTP or BCTP 401 with Bacillus cereus prior to subcutaneous injection in mice reduced the resulting skin lesion by 99%. Wound irrigation with BCTP 1 h after spore inoculation yielded a 98% reduction in skin lesion size, and mortality was reduced 3-fold. These nanoemulsion formulas are stable, easily dispersed, nonirritant, and nontoxic compared with other available sporicidal agents.

Chronic inflammation in the stomach induces metaplasia, the pre-cancerous lesion that precedes inflammation-driven neoplastic transformation. While Hedgehog signaling contributes to the initiation of some cancers, its role in gastric transformation remains poorly defined. We found that Helicobacter-infected C57BL/6 mice develop extensive mucous cell metaplasia at 6 month but not at 2 months post-infection. Gastric metaplasia coincided with the appearance of CD45+MHCII+CD11b+CD11c+ myeloid cells that were normally not present in the chronic gastritis at 2 months. The myeloid regulatory gene Schlafen-4 was identified in a microarray analysis comparing infected WT versus Gli1 null mice and was expressed in the CD11b+CD11c+ myeloid population. Moreover this same population expressed IL-1β and TNFα pro-inflammatory cytokines. By 6 months, the mucous neck cell metaplasia (SPEM) expressed IL-6, phosphorylated STAT3 and the proliferative marker Ki67. Expression was not observed in Gli1 mutant mice consistent with the requirement of Gli1 to induce this pre-neoplastic phenotype. Ectopic Shh ligand expression alone was not sufficient to induce SPEM, but with Helicobacter infection synergistically increased the histologic severity observed with the inflammation. Therefore Hedgehog signaling is required, but is not sufficient to generate pre-neoplastic changes during chronic gastritis. Gli1-dependent myeloid cell differentiation plays a pivotal role in the appearance of myeloid cell subtypes ostensibly required for SPEM development. Moreover, it suggests that therapies capable of targeting this phenotypic switch might prevent progression to metaplasia, the pre-neoplastic change that develops prior to dysplasia and gastric cancer, which also occurs in other epithelial-derived neoplasias initiated by chronic inflammation.

An unusual mycoplasma, which was isolated from the urine of a human immunodeficiency virus-positive male homosexual patient, has an elongated flask shape and two unique sharply divided internal compartments. The tiplike compartment is densely packed with fine granules, and the body compartment is loosely filled with coarse granules consistent with ribosomal structures. The organism has properties of adherence, hemadsorption, and cytadsorption and invades many different types of mammalian cells. Adhesion and penetration apparently involve the terminally located tiplike structure. Cholesterol is required for growth, and the mycoplasma ferments glucose and hydrolyzes arginine, but does not hydrolyze urea. The results of DNA homology studies revealed that this organism is not genetically related to previously described mycoplasma species that have the same biochemical properties. The results of serologic studies demonstrated that this organism is antigenically distinct from all previously described mycoplasmas. We propose that this new mollicute species should be named Mycoplasma penetrans sp. nov. The type strain is strain GTU-54-6A1 (= ATCC 55252).A total of 13 members of the class Mollicutes have been isolated from humans (5, 14, 35). The two most common isolation sites are respiratory and urogenital tracts (5, 3 9 , although isolation from synovial fluids of patients with arthritis (23) and isolation from other anatomical sites have also been reported (15,26,28).The most common mycoplasmas in human urogenital tracts are Mycoplasma hominis and Ureaplasma urealyticum (10, 35). Mycoplasma fernentans, Mycoplasma genitalium, Mycoplasma spermatophilum , Mycoplasma primaturn , Mycoplasma salivarium, and Mycoplasma pneumoniae are less common (5,14,35,37). The frequency of isolation of urogenital mycoplasmas depends in part on the group of individuals studied. Sexual activity, as well as multiple sexual partners, increases the rate of isolation (25). The isolation rates for urogenital mycoplasmas are also different in heterosexual and homosexual males (16).To date, there has been no systematic study of the urogenital mycoplasmas isolated from patients with AIDS. Our previous examination of urine samples from a small number of patients with AIDS in which we used the polymerase chain reaction and cultures for mycoplasmas revealed a high level of M. fermentam infection which was not found in non-AIDS controls (8). In a more comprehensive study, we isolated a previously unknown mycoplasma from urine samples from six patients with AIDS (18). In this paper we describe this organism and its unusual characteristics; we also describe our examination of its distinct biological, serological, and genetic properties, which was carried out in order to establish whether this organism should be given taxonomic status as a new mycoplasma species.* Corresponding author. MATERIALS AND METHODSIsolation and cultivation. SP-4 medium was prepared as described below. A 10-g portion of Tryptone (Difco Laboratories, Detroit, Mich.), 5.3 g of pept...

Chronic Helicobacter pylori infection triggers neoplastic transformation of the gastric mucosa in a small subset of patients, but the risk factors that induce progression to gastric metaplasia have not been identified. Prior to cancer development, the oxyntic gastric glands atrophy and are replaced by metaplastic cells in response to chronic gastritis. Previously, we identified schlafen 4 (Slfn4) as a GLI1 target gene and myeloid differentiation factor that correlates with spasmolytic polypeptide-expressing metaplasia (SPEM) in mice. Here, we tested the hypothesis that migration of SLFN4-expressing cells from the bone marrow to peripheral organs predicts preneoplastic changes in the gastric microenvironment. Lineage tracing in Helicobacter-infected Slfn4 reporter mice revealed that SLFN4+ cells migrated to the stomach, where they exhibited myeloid-derived suppressor cell (MDSC) markers and acquired the ability to inhibit T cell proliferation. SLFN4+ MDSCs were not observed in infected GLI1-deficient mice. Overexpression of sonic hedgehog ligand (SHH) in infected WT mice accelerated the appearance of SLFN4+ MDSCs in the gastric corpus. Similarly, in the stomachs of H. pylori-infected patients, the human SLFN4 ortholog SLFN12L colocalized to cells that expressed MDSC surface markers CD15+CD33+HLA-DRlo. Together, these results indicate that SLFN4 marks a GLI1-dependent population of MDSCs that predict a shift in the gastric mucosa to a metaplastic phenotype.

No abstract

For many proteins, aggregation is one part of a structural equilibrium that can occur. Balancing productive aggregation versus pathogenic aggregation that leads to toxicity is critical and known to involve adenosine triphosphate (ATP) dependent action of chaperones and disaggregases. Recently a second activity of ATP was identified, that of a hydrotrope which, independent of hydrolysis, was sufficient to solubilize aggregated proteins in vitro. This novel function of ATP was postulated to help regulate proteostasis in vivo. We tested this hypothesis on aggregates found in Xenopus oocyte nucleoli. Our results indicate that ATP has dual roles in the maintenance of protein solubility. We provide evidence of endogenous hydrotropic action of ATP but show that hydrotropic solubilization of nucleolar aggregates is preceded by a destabilizing event. Destabilization is accomplished through an energy dependent process, reliant upon ATP and one or more soluble nuclear factors, or by disruption of a co-aggregate like RNA.

Mycoplasma penetrans, a novel mycoplasma isolated from HIV-1-infected patients with AIDS, has pathogenic properties associated with in-vivo virulence. Enzyme-linked immunosorbent assay and western blotting detected a more than 100 times higher frequency of antibodies to the mycoplasma in serum from HIV-1-infected patients with AIDS (40%) than from HIV-negative controls (0.3%). Serum from 20% of HIV-1-infected, symptom-free individuals also had M penetrans specific antibodies. The antibodies' major immunoreactivity was directed against P35 and P38, the two main lipid-associated membrane protein antigens of the organism. Patients attending sexually transmitted disease clinics had a low frequency of antibody (0.9%). None of 178 HIV-negative patients with different non-AIDS diseases, many associated with immune dysfunction and/or low white cell counts, tested positive for the antibodies. M penetrans, apparently not a commensal and not a simple opportunist, is uniquely associated with HIV-1 infection and AIDS.