Pepper Mild Mottle Virus, a Plant Virus Associated with Specific Immune Responses, Fever, Abdominal Pains, and Pruritus in Humans

Background: Recently, metagenomic studies have identified viable Pepper mild mottle virus (PMMoV), a plant virus, in the stool of healthy subjects. However, its source and role as pathogen have not been determined. Methods and Findings: 21 commercialized food products containing peppers, 357 stool samples from 304 adults and 208 stool samples from 137 children were tested for PMMoV using real-time PCR, sequencing, and electron microscopy. Anti-PMMoV IgM antibody testing was concurrently performed. A case-control study tested the association of biological and clinical symptoms with the presence of PMMoV in the stool. Twelve (57%) food products were positive for PMMoV RNA sequencing. Stool samples from twenty-two (7.2%) adults and one child (0.7%) were positive for PMMoV by real-time PCR. Positive cases were significantly more likely to have been sampled in Dermatology Units (p<10−6), to be seropositive for anti-PMMoV IgM antibodies (p = 0.026) and to be patients who exhibited fever, abdominal pains, and pruritus (p = 0.045, 0.038 and 0.046, respectively). Conclusions: Our study identified a local source of PMMoV and linked the presence of PMMoV RNA in stool with a specific immune response and clinical symptoms. Although clinical symptoms may be imputable to another cofactor, including spicy food, our data suggest the possibility of a direct or indirect pathogenic role of plant viruses in humans

2b80 − Hydroxybisphosphonate Linked Doxorubicin: Bone Targeted Strategy for Treatment of Osteosarcoma

International audienceTo reply to as yet unmet medical needs to treat osteosarcoma, a form of primary bone cancer, we conceived the 12b80 compound by covalently conjugating antineoplastic compound doxorubicin to a bone targeting hydroxybisphosphonate vector and turned it into a prodrug through a custom linker designed to specifically trigger doxorubicin release in acidic bone tumor microenvironment. Synthesis of 12b80 was thoroughly optimized to be produced at gram scale. 12b80 was evaluated in vitro for high bone support affinity, specific release of doxorubicin in acidic condition, lower cytotoxicity, and cellular uptake of the prodrug. In vivo in rodents, 12b80 displayed rapid and sustained targeting of bone tissue and tumor-associated heterotopic bone and permitted a higher doxorubicin payload in tumor bone environment compared to nonvectorized doxorubicin. Consequently, 12b80 showed much lower toxicity compared to doxorubicin, promoted strong antitumor effects on rodent orthotopic osteosarcoma, displayed a dose-response therapeutic effect, and was more potent than doxorubicin/zoledronate combination

Electron microscopy of <i>Pepper mild mottle virus</i> (PMMoV)-RNA positive samples.

<p>Footnote: The samples analyzed by electron microscopy were (a) Tabasco sauce; (b) PMMoV purified from Tabasco sauce. The samples analyzed following immunogold staining were: (c) PMMoV purified from Tabasco sauce; (d) a PMMoV-RNA positive patient's stool sample; (e) PMMoV purified from Tabasco sauce stained with antibodies from a non immunized mouse (negative control no.1) and (f) a rotavirus-positive sample (negative control no.2).</p

Comparison of the serum anti-PMMoV antibody level (a, total antibody; b, IgM) between individuals with PMMoV RNA-positive and PMMoV RNA-negative stool.

<p>The dashed lines indicate the optical density cut-off values that were chosen for positive PMMoV serology using the receiver operating characteristic (ROC) curve test.</p

Local lesions typical of PMMoV infection on <i>Nicotiana tabacum</i> cultivar Xanthi NN plants following inoculation of processed PMMoV RNA-positive food products.

<p>Footnote: Leaves of <i>Nicotiana tabacum</i> cultivar Xanthi NN plants (a, e) non inoculated (negative control); (b, f) inoculated with buffer only (negative control); (c, and detail: d) inoculated with a processed PMMoV RNA-positive Tabasco sample; (g, and detail: h) inoculated with a PMMoV RNA-positive food product (no. 17; <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010041#pone-0010041-t001" target="_blank">Table 1</a>).</p

Univariate analysis for risk factors and biological and clinical features in association with the detection by real-time PCR of PMMoV RNA from stools.

<p>Footnote: -. undefined; Nb, Number; Nc, not calculable; <i>p</i> values <0.05 are in boldface.</p>a<p>63 years was the median age of the adult patients tested in the case-control study.</p>b<p>Blood markers of inflammation were elevated erythrocyte sedimentation rate, and/or C-reactive protein and fibrinogen levels in serum.</p

Summary of postulates and findings about interactions of PMMoV with the host immune system, its replication in non-plant tissues, and its potential link with clinical signs.

<p>Summary of postulates and findings about interactions of PMMoV with the host immune system, its replication in non-plant tissues, and its potential link with clinical signs.</p

Phylogenetic comparison of PMMoV nucleotide sequences recovered in the present study and corresponding (a) to a region located near the 5′ end of the genome or (b) to a region in the capsid gene to PMMoV sequences selected from GenBank.

<p>Footnote: The phylogenetic trees were constructed using the neighbor-joining method based on the 5′ region (a) of the PMMoV genome or a region in the capsid gene (b). The PMMoV sequences recovered from patients' stool in the present study are in the boldface, white font and are indicated by a black square. Their name is labeled as follows: Mars_Laboratory identification number_Gender-Age_Clinical unit where the patient received care. The PMMoV sequences recovered from food products in the present study are in a boldface and are indicated by a gray square. Their name is labeled as follows: Mars_Name of the food product_Country where food product was manufactured. The remaining PMMoV sequences were obtained from GenBank. Their name is labeled as follows: GenBank Accession no._Coutry of origin_Year of submission to GenBank. Bootstrap values are indicated when greater than 50% as a percentage obtained from 1,000 resamplings of the data. The scale bar indicates the number of nucleotide substitutions per site. The sequence of <i>Tobacco mild green mosaic virus</i> (GenBank Accession No. NC_001556) and <i>Tropical soda apple mosaic virus</i> (GenBank Accession No. AY956381) were used as outgroups.</p

PMMoV RNA sequences recovered from food products.

<p>PMMoV RNA sequences recovered from food products.</p