BACKGROUND: Presensitized patients with circulating donor-specific antibodies (DSAs) before transplantation are at risk for antibody-mediated rejection (AMR). Peritransplant desensitization mitigates but does not eliminate the alloimmune response. We examined the possibility that subthreshold AMR activity undetected by histology could be operating in some early biopsies. METHODS: Transcriptome of kidney allograft biopsies performed within the first month in presensitized patients (DSA+) who had received desensitization and did not develop active/probable AMR by histology (R-) was compared with biopsies showing active/probable AMR (R+/DSA+). As negative controls, biopsies without rejection by histology in patients without DSA at transplantation were used (R-/DSA-). RNA sequencing from biopsies selected from the biobank was used in cohort 1 (n = 32) and microarray, including the molecular microscope (Molecular Microscope Diagnostic System [MMDx]) algorithm, in recent cohort 2 (n = 30). RESULTS: The transcriptome of R-/DSA+ was similar to R+/DSA+ as these groups differed in 14 transcripts only. Contrarily, large differences were found between both DSA+ groups and negative controls. Fast gene set enrichment analyses showed upregulation of the immune system in both DSA+ groups (gene ontology terms: adaptive immune response, humoral immune response, antigen receptor-mediated signaling, and B-cell receptor signaling or complement activation) when compared with negative controls. MMDx assessment in cohort 2 classified 50% of R-/DSA+ samples as AMR and found no differences in AMR molecular scores between R+ and R- DSA+ groups. In imlifidase desensitization, MMDx series showed a gradual increase in AMR scores over time. CONCLUSIONS: Presensitized kidney transplant recipients exhibited frequent molecular calls of AMR in biopsy-based transcript diagnostics despite desensitization therapy and negative histology.
- Publikační typ
- časopisecké články MeSH
Tick-borne encephalitis virus (TBEV) is the most medically relevant tick-transmitted Flavivirus in Eurasia, targeting the host central nervous system and frequently causing severe encephalitis. The primary function of its capsid protein (TBEVC) is to recruit the viral RNA and form a nucleocapsid. Additional functionality of Flavivirus capsid proteins has been documented, but further investigation is needed for TBEVC. Here, we show the first capsid protein 3D structure of a member of the tick-borne flaviviruses group. The structure of monomeric Δ16-TBEVC was determined using high-resolution multidimensional NMR spectroscopy. Based on natural in vitro TBEVC homodimerization, the dimeric interfaces were identified by hydrogen deuterium exchange mass spectrometry (MS). Although the assembly of flaviviruses occurs in endoplasmic reticulum-derived vesicles, we observed that TBEVC protein also accumulated in the nuclei and nucleoli of infected cells. In addition, the predicted bipartite nuclear localization sequence in the TBEVC C-terminal part was confirmed experimentally, and we described the interface between TBEVC bipartite nuclear localization sequence and import adapter protein importin-alpha using X-ray crystallography. Furthermore, our coimmunoprecipitation coupled with MS identification revealed 214 interaction partners of TBEVC, including viral envelope and nonstructural NS5 proteins and a wide variety of host proteins involved mainly in rRNA processing and translation initiation. Metabolic labeling experiments further confirmed that TBEVC and other flaviviral capsid proteins are able to induce translational shutoff and decrease of 18S rRNA. These findings may substantially help to design a targeted therapy against TBEV.
A tyrosine kinase inhibitor, vandetanib (Van), is an anticancer drug affecting the signaling of VEGFR, EGFR and RET protooncogenes. Van is primarily used for the treatment of advanced or metastatic medullary thyroid cancer; however, its usage is significantly limited by side effects, particularly cardiotoxicity. One approach to minimize them is the encapsulation or binding of Van in- or onto a suitable carrier, allowing targeted delivery to tumor tissue. Herein, we constructed a nanocarrier based on apoferritin associated with Van (ApoVan). Based on the characteristics obtained by analyzing the average size, the surface ζ-potential and the polydispersive index, ApoVan nanoparticles exhibit long-term stability and maintain their morphology. Experiments have shown that ApoVan complex is relatively stable during storage. It was found that Van is gradually released from its ApoVan form into the neutral environment (pH 7.4) as well as into the acidic environment (pH 6.5). The effect of free Van and ApoVan on neuroblastoma and medullary thyroid carcinoma cell lines revealed that both forms were toxic in both used cell lines, and minimal differences between ApoVan and Van were observed. Thus, we assume that Van might not be encapsulated into the cavity of apoferritin, but instead only binds to its surface.
We studied the in vitro metabolism of the anti-thyroid-cancer drug vandetanib in a rat animal model and demonstrated that N-desmethylvandetanib and vandetanib N-oxide are formed by NADPH- or NADH-mediated reactions catalyzed by rat hepatic microsomes and pure biotransformation enzymes. In addition to the structural characterization of vandetanib metabolites, individual rat enzymes [cytochrome P450 (CYP) and flavin-containing monooxygenase (FMO)] capable of oxidizing vandetanib were identified. Generation of N-desmethylvandetanib, but not that of vandetanib N-oxide, was attenuated by CYP3A and 2C inhibitors while inhibition of FMO decreased formation of vandetanib N-oxide. These results indicate that liver microsomal CYP2C/3A and FMO1 are major enzymes participating in the formation of N-desmethylvandetanib and vandetanib N-oxide, respectively. Rat recombinant CYP2C11 > >3A1 > 3A2 > 1A1 > 1A2 > 2D1 > 2D2 were effective in catalyzing the formation of N-desmethylvandetanib. Results of the present study explain differences between the CYP- and FMO-catalyzed vandetanib oxidation in rat and human liver reported previously and the enzymatic mechanisms underlying this phenomenon.
- MeSH
- antitumorózní látky metabolismus MeSH
- chinazoliny metabolismus MeSH
- jaterní mikrozomy MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- oxidace-redukce MeSH
- oxygenasy metabolismus MeSH
- piperidiny metabolismus MeSH
- systém (enzymů) cytochromů P-450 metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
