Effects of hydrophobic substitutions at position 18 on the potency of parathyroid hormone antagonists

Position 18 in a parathyroid hormone (PTH) antagonist, [Nle8,18,Tyr34]bPTH(7-34)NH2 (ii), was shown to tolerate substitutions by a range of amino acids with retention of inhibitory activity. The effects of hydrophobic substitutions at this position as a means of enhancing binding interactions with the receptor were evaluated. Substitution of Nle at position 18 with either D-Ala, D-Trp, or L-Trp in analog ii or with Trp (D or L) in the recently reported, highly potent antagonist, [Nle8,18,D-Trp12,Tyr34]bPTH(7-34)NH2 (in vitro activities; Kb = 15 nM and Ki = 125 nM), was performed. In terms of activity on renal receptors, one antagonist, [Nle8,D-Trp12,18,Tyr34]bPTH(7-34)NH2, is the most active in vitro PTH antagonist yet reported (Kb = 4 nM; Ki = 30 nM). The rationale for design of this antagonist and the conclusions regarding PTH-receptor interactions are discussed.     

Affinity of Ionic Species of Nucleoside Transport Protein Inhibitors

Abstract

A class of very potent nucleoside transport inhibitors is present in two molecular forms around physiological pH. We investigated whether the monoprotonated or the unionized species of these molecules binds to this camer protein with higher affinity.     

An Enhanced Heterologous Virus-Like Particle for Human Papillomavirus Type 16 Tumour Immunotherapy

Cervical cancer is caused by high-risk, cancer-causing human papillomaviruses (HPV) and is the second highest cause of cancer deaths in women globally. The majority of cervical cancers express well-characterized HPV oncogenes, which are potential targets for immunotherapeutic vaccination. Here we develop a rabbit haemorrhagic disease virus (RHDV) virus-like particle (VLP)-based vaccine designed for immunotherapy against HPV16 positive tumours. An RHDV-VLP, modified to contain the universal helper T cell epitope PADRE and decorated with an MHC I-restricted peptide (aa 48–57) from the HPV16 E6, was tested for its immunotherapeutic efficacy against the TC-1 HPV16 E6 and E7-expressing tumour in mice. The E6-RHDV-VLP-PADRE was administered therapeutically for the treatment of a pre-existing TC-1 tumour and was delivered with antibodies either to deplete regulatory T cells (anti-CD25) or to block T cell suppression mediated through CTLA-4. As a result, the tumour burden was reduced by around 50% and the median survival time of mice to the humane endpoint was almost doubled the compared to controls. The incorporation of PADRE into the RHDV-VLP was necessary for an E6-specific enhancement of the anti-tumour response and the co-administration of the immune modifying antibodies contributed to the overall efficacy of the immunotherapy. The E6-RHDV-VLP-PADRE shows immunotherapeutic efficacy, prolonging survival for HPV tumour-bearing mice. This was enhanced by the systemic administration of immune-modifying antibodies that are commercially available for use in humans. There is potential to further modify these particles for even greater efficacy in the path to development of an immunotherapeutic treatment for HPV precancerous and cancer stages.     

THE EFFECTS OF INJURY PREVENTION WARM-UP PROGRAMMES ON KNEE STRENGTH IN MALE SOCCER PLAYERS

The study investigates the effects of the 11+ and HarmoKnee injury prevention programmes on knee strength in male soccer players. Under-21-year-old players (n=36) were divided equally into: the 11+, HarmoKnee and control groups. The programmes were performed for 24 sessions (20-25 min each). The hamstrings and quadriceps strength were measured bilaterally at 60°·s^-1, 180°·s^-1 and 300°·s^-1. The concentric quadriceps peak torque (PT) of the 11+ increased by 27.7% at 300°·s^-1 in the dominant leg (p<0.05). The concentric quadriceps PT of HarmoKnee increased by 36.6%, 36.2% and 28% in the dominant leg, and by 31.3%, 31.7% and 20.05% at 60°·s^-1, 180°·s^-1 and 300°·s^-1 in the non-dominant leg respectively. In the 11+ group the concentric hamstring PT increased by 22%, 21.4% and 22.1% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, respectively in the dominant leg, and by 22.3%, and 15.7% at 60°·s^-1 and 180°·s^-1, in the non-dominant leg. In the HarmoKnee group the hamstrings in the dominant leg showed an increase in PT by 32.5%, 31.3% and 14.3% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, and in the non-dominant leg hamstrings PT increased by 21.1% and 19.3% at 60°·s^-1 and 180°·s^-1 respectively. The concentric hamstrings strength was significantly different between the 11+ and control groups in the dominant (p=0.01) and non-dominant legs (p=0.02). The HarmoKnee programme enhanced the concentric strength of quadriceps. The 11+ and HarmoKnee programmes are useful warm-up protocols for improving concentric hamstring strength in young professional male soccer players. The 11+ programme is more advantageous for its greater concentric hamstring strength improvement compared to the HarmoKnee programme.