TRIzol-based RNA extraction for detection protocol for SARS-CoV-2 of coronavirus disease 2019

International audienceDiagnostic testing is important for managing the 2019 novel coronavirus (SARS-CoV-2). We developed an optimized protocol for SARS-CoV-2 RNA extraction from the surface of the respiratory mucosa with nasopharyngeal swabs and compared the sensitivity of RNA extraction methods. RNA extraction was performed using three different procedures (TRIzol, QIAamp, VMT-TRIzol) from nine positive SARS-CoV-2 samples. SARS-CoV-2 was detected by real-time reverse transcriptase PCR (RT-PCR) using a detection kit for SARS-CoV-2 (Sun Yat-sen University). Compared to RT-PCR results, there were no discernible differences in detection rates when comparing the three different extraction procedures. On the basis of these results, the use of TRIzol as a transport medium and RNA extraction method for SARS-CoV-2 detection may be a helpful alternative for laboratories facing shortages of commercial testing kits

Nectin 4 Overexpression in Ovarian Cancer Tissues and Serum

Early detection of ovarian cancer is difficult owing to the lack of specific and sensitive tests available. Previously, we found expression of nectin 4 to be increased in ovarian cancer compared with normal ovaries. Reverse transcriptase–polymerase chain reaction (RT-PCR) and quantitative RT-PCR validated the overexpression of nectin 4 messenger RNA in ovarian cancer compared with normal ovarian cell lines and tissues. Protein levels of nectin 4 were elevated in ovarian cancer cell lines and tissue compared with normal ovarian cell lines as demonstrated by Western immunoblotting, flow cytometry, and immunohistochemical staining of tissue microarray slides. Cleaved nectin 4 was detectable in a number of patient serum samples by enzyme-linked immunosorbent assay. In patients with benign gynecologic diseases with high serum CA125 levels, nectin 4 was not detected in the majority of cases, suggesting that nectin 4 may serve as a potential biomarker that helps discriminate benign gynecologic diseases from ovarian cancer in a panel with CA125

Effect of nisin on biogenic amines and shelf life of vacuum packaged rainbow trout (Oncorhynchus mykiss) fillets

Nisin is a lantibiotic exhibiting antimicrobial activity against a wide range of Gram-positive bacteria, or some Gram-negative bacteria when used in combination with other preservative agents. The objective of the present work was to study the effect of a nisin treatment on biogenic amines occurrence and shelf life of refrigerated (4°C) vacuum packaged rainbow trout samples. For this purpose samples were divided in two batches: the experimental batch (CB-N), consisting of samples immersed in sterilized broth formulated with soy milk 1.4% (v/v) and whey powder 11.2 % (w/v) dissolved in deionized water with addition of nisin (500 mg L-1); the control batch (CB), consisting of samples immersed in the former broth without addition of nisin. A positive effect of nisin resulted on colour stability; in fact, the global colour index ΔE remained constant during the storage of treated rainbow trout samples, while it increased in the control. However, the behaviour of microbiota, texture, smell and biogenic amines were comparable between fillet samples treated with nisin broth and with control medium (without nisin). No inhibitory effects of nisin on biogenic amines accumulation was observed; conversely, the decline of histamine content (about 30 %), observed only in fishes of the control batch, may be correlated to the presence of histamine-degradating bacteria (Pseudomonas species). Further studies are necessary to investigate nisin action mechanism on the colour, an important physical characteristic involved in the product quality and consumer acceptability

Identification of a naturally processed HLA-A*02:01-restricted CTL epitope from the human tumor-associated antigen Nectin-4.

Nectin-4 is a tumor antigen present on the surface of breast, ovarian and lung carcinoma cells. It is rarely present in normal adult tissues and is therefore a candidate target for cancer immunotherapy. Here, we identified a Nectin-4 antigenic peptide that is naturally presented to T cells by HLA-A2 molecules. We first screened the 502 nonamer peptides of Nectin-4 (510 amino acids) for binding to and off-rate from eight different HLA class I molecules. We then combined biochemical, cellular and algorithmic assays to select 5 Nectin-4 peptides that bound to HLA-A*02:01 molecules. Cytolytic T lymphocytes were obtained from healthy donors, that specifically lyzed HLA-A2(+) cells pulsed with 2 out of the 5 peptides, indicating the presence of anti-Nectin-4 CD8(+) T lymphocytes in the human T cell repertoire. Finally, an HLA-A2-restricted cytolytic T cell clone derived from a breast cancer patient recognized peptide Nectin-4145-153 (VLVPPLPSL) and lyzed HLA-A2(+) Nectin-4(+) breast carcinoma cells. These results indicate that peptide Nectin-4145-153 is naturally processed for recognition by T cells on HLA-A2 molecules. It could be used to monitor antitumor T cell responses or to immunize breast cancer patients