LAT-8881

Novel host‐targeted therapeutics could treat severe influenza A virus (IAV) infections, with reduced risk of drug resistance. LAT8881 is a synthetic form of the naturally occurring C‐terminal fragment of human growth hormone. Acting independently of the growth hormone receptor, it can reduce inflammation‐induced damage and promote tissue repair in an animal model of osteoarthritis. LAT8881 has been assessed in clinical trials for the treatment of obesity and neuropathy and has an excellent safety profile. We investigated the potential for LAT8881, its metabolite LAT9991F and LAT7771 derived from prolactin, a growth hormone structural homologue, to treat severe IAV infection.

LAT8881, LAT9991F and LAT7771 were evaluated for their effects on cell viability and IAV replication in vitro, as well as their potential to limit disease in a preclinical mouse model of severe IAV infection.

In vitro LAT8881 treatment enhanced cell viability, particularly in the presence of cytotoxic stress, which was countered by siRNA inhibition of host lanthionine synthetase C‐like proteins. Daily intranasal treatment of mice with LAT8881 or LAT9991F, but not LAT7771, from day 1 postinfection significantly improved influenza disease resistance, which was associated with reduced infectious viral loads, reduced pro‐inflammatory cytokines and increased abundance of protective alveolar macrophages. LAT8881 treatment in combination with the antiviral oseltamivir phosphate led to more pronounced reduction in markers of disease severity than treatment with either compound alone.

These studies provide the first evidence identifying LAT8881 and LAT9991F as novel host‐protective therapies that improve survival, limit viral replication, reduce local inflammation and curtail tissue damage during severe IAV infection. Evaluation of LAT8881 and LAT9991F in other infectious and inflammatory conditions of the airways is warranted.

Peptidic drugs with wide spectrum of physiological activity are of interest for cheating athletes and can be misused as doping in sports. A growing number of small peptide drugs capable of enhancing performance are included in the prohibited list issued by World Anti-Doping Agency (WADA), therefore the improvement of the detection methods is constantly needed. In the present study, a screening assay was developed comprising 54 prohibited small peptides and the related substances in urine by means of the alkaline pre-activated weak cation exchange-solid phase extraction (WCX-SPE) with liquid chromatography-high resolution mass spectrometry (LCHRMS). This method performed good enrichment and purification effect of traditional WCX for basic peptides, and also improve the purification power of acidic peptides, which significantly expanded the coverage of detection substances. The method was validated in accordance with WADA relevant criteria and validated with a main focus on qualitative parameters including selectivity, limits of detection (0.02-0.2 ng/mL), linearity (0.1-20 ng/mL for 46 analytes and 0.2-20 ng/mL for 9 analytes), accuracy and precision (RE% and RSD% < 20% at 1, 5 and 10 ng/mL), recovery (39.2%-100.1% except for the TB500(1-2) free acid: 9.2%), matrix effects (ion suppression effect: 0 to 49.4% and ion enhancement effect: 100% and 264.6%), carryover, reliability and sample extract stability. As a proof-of-principle, urine samples from two patients received a single injection of leuprorelin acetate microspheres (3.75 mg) 30 days before were analyzed and the results proved the applicability of the method.