Diagnostic phase antibody response to the human papillomavirus type 16 E2 protein is associated with succesful treatment of genital HPV lesions with systemic interferon α-2b

Background and objective: Systemic interferon α-2b treatment reduces relapses of genital human papillomavirus (HPV) lesions in some but not all females. The aim of the present study was to investigate possible predictive pretreatment factors for the outcome of therapy.Material and methods: HPV DNA status and HPV antibody response were evaluated in 100 randomized patients treated with laser ablation and systemic interferon α-2b or placebo, and followed up to 6 months.Results: Overall, adjuvant therapy with systemic interferon-α did not differ from placebo. However, detectable diagnostic phase levels of serum antibodies to e.g. HPV16 open reading frame (ORF) E2 derived peptide ¹⁴¹EEASVTVVEGQVDYY¹⁵⁵ predicted 10-fold difference in the risk of recurrence of HPV infection following adjuvant interferon α-2b therapy as compared with placebo (odds ratio, OR, 0.5, 95% confidence interval (CI), 0.1–2.3; OR, 4.6, 95% CI 0.5–41, respectively). This trend was statistically significant in the whole study population (2P < 0.05), and in patients with high viral load (2P < 0.01).Conclusions: Evaluation of the E2 antibody responses may help to identify women with genital HPV lesions who respond to systemic interferon α-2b treatment.     

High-level expression of a recombinant fragment of human fibronectin containing the Cell I–Hep II–IIICS71 domain in Escherichia coli as a soluble protein

Fibronectin (FN) is a major matrix protein that is involved in multiple processes. Its Cell I–Hep II domain is potentially useful in tumor therapy. Here, a recombinant fragment of FN with the Cell I–Hep II-IIICS71 domain, CH/71, was expressed in Escherichia coli. The CH/71 fusion protein consists of Cell I–Hep II domain and 19th to 89th amino acids of IIICS domain of FN. The expression level of CH/71 in E. coli was very high after induction with IPTG. Furthermore, CH/71 protein was largely found in the soluble fraction. It was readily purified by one-step heparin–agarose affinity chromatograph. The ability of CH/71 binding cells was about 8-fold of that of Cell I–Hep II domain FN.     

Molecular interactions of type I and type II positive allosteric modulators with the human α7 nicotinic acetylcholine receptor: an in silico study

The binding site locations and structural components for type I and type II positive allosteric modulators (PAMs) of the α7 nicotinic acetylcholine receptor (nAChR) have not been fully characterized yet. In this regard, homology models of the human α7 nAChR and hα7/m5-HT_3A chimera, built using the crystal structure of the serotonin type 3A receptor (5-ΗΤ_3ΑR), were used for molecular docking and molecular dynamics simulations to study the molecular interactions of selected type I (5-hydroxyindol, NS-1738, and LY-2087101) and type II (PNU-120596, PAM-2, and TBS-516) PAMs. The docking results indicate: (1) a site located in the extracellular domain (ECD) for type I PAMs such as NS-1738 and LY-2087101, but not for 5-HI; (2) an overlapping site in the ECD–transmembrane domain (TMD) junction for all studied PAMs. Additional docking results on the hα7/m5-HT_3A chimera supported experimental results indicating that the ECD site might be relevant for type I PAM activity; and (3) two TMD sites, an intrasubunit site that recognizes type II PAMs, and an intersubunit pocket with high specificity for 5-HI (type I PAM). The in silico α7TSLMF mutant results support the view that M1–Ser223 and M3–Ile281 are key residues for the interaction of PAM-2 and PNU-120596 with the intrasubunit cavity. Our in silico results are in agreement with experimental data showing that the intrasubunit cavity is relevant for the activity of type II PAMs, and suggest that the ECD–TMD junction and intersubunit sites could be significant for the activity of type I PAMs.