TP73 is a member of the TP53 gene family and produces N- and C-terminal protein isoforms through alternative promoters, alternative translation initiation and alternative splicing. Most notably, p73 protein isoforms may either contain a p53-like transactivation domain (TAp73 isoforms) or lack this domain (ΔTAp73 isoforms) and these variants have opposing or independent functions. To date, there is a lack of well-characterised isoform-specific p73 antibodies. Here, we produced polyclonal and monoclonal antibodies to N-terminal p73 variants and the C-terminal p73α isoform, the most common variant in human tissues. These reagents show that TAp73 is a marker of multiciliated epithelial cells, while ΔTAp73 is a marker of non-proliferative basal/reserve cells in squamous epithelium. We were unable to detect ΔNp73 variant proteins, in keeping with recent data that this is a minor form in human tissues. Most cervical squamous cell carcinomas (79%) express p73α, and the distribution of staining in basal cells correlated with lower tumour grade. TAp73 was found in 17% of these tumours, with a random distribution and no association with clinicopathological features. These data indicate roles for ΔTAp73 in maintaining a non-proliferative state of undifferentiated squamous epithelial cells and for TAp73 in the production of differentiated multiciliated cells.

• Klíčová slova
• Cervical cancer, Endometrium, Fallopian tube, Multiciliated cells, Squamous epithelial stem cells, p73 isoforms,
• MeSH
• epitelové buňky metabolismus   MeSH
• lidé MeSH
• monoklonální protilátky MeSH
• nádorové buněčné linie MeSH
• nádory děložního čípku metabolismus   patologie   genetika   MeSH
• nádory metabolismus   patologie   genetika   MeSH
• protein - isoformy * metabolismus   genetika   MeSH
• protein p73 * metabolismus   genetika   MeSH
• spinocelulární karcinom metabolismus   patologie   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• delta Np73 protein, human MeSH Prohlížeč
• monoklonální protilátky MeSH
• protein - isoformy * MeSH
• protein p73 * MeSH
• TP73 protein, human MeSH Prohlížeč

Interferon induced transmembrane proteins (IFITMs) play a dual role in the restriction of RNA viruses and in cancer progression, yet the mechanism of their action remains unknown. Currently, there is no data about the basic biochemical features or biophysical properties of the IFITM1 protein. In this work, we report on description and biochemical characterization of three conformational variants/oligomeric species of recombinant IFITM1 protein derived from an Escherichia coli expression system. The protein was extracted from the membrane fraction, affinity purified, and separated by size exclusion chromatography where two distinct oligomeric species were observed in addition to the expected monomer. These species remained stable upon re-chromatography and were designated as "dimer" and "oligomer" according to their estimated molecular weight. The dimer was found to be less stable compared to the oligomer using circular dichroism thermal denaturation and incubation with a reducing agent. A two-site ELISA and HDX mass spectrometry suggested the existence of structural motif within the N-terminal part of IFITM1 which might be significant in oligomer formation. Together, these data show the unusual propensity of recombinant IFITM1 to naturally assemble into very stable oligomeric species whose study might shed light on IFITM1 anti-viral and pro-oncogenic functions in cells.

• Klíčová slova
• IFITM proteins, hydrogen deuterium exchange, oligomerization, protein conformation, protein structure,
• MeSH
• antivirové látky farmakologie   chemie   metabolismus   MeSH
• diferenciační antigeny * metabolismus   chemie   MeSH
• konformace proteinů * MeSH
• lidé MeSH
• rekombinantní proteiny chemie   izolace a purifikace   metabolismus   biosyntéza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antivirové látky MeSH
• diferenciační antigeny * MeSH
• leu-13 antigen MeSH Prohlížeč
• rekombinantní proteiny MeSH

Monoclonal antibodies targeting immune checkpoints have revolutionized oncology. Yet, the effectiveness of these treatments varies significantly among patients, and they are associated with unexpected adverse events, including hyperprogression. The murine research model used in drug development fails to recapitulate both the functional human immune system and the population heterogeneity. Hence, a novel model is urgently needed to study the consequences of immune checkpoint blockade. Dogs appear to be uniquely suited for this role. Approximately 1 in 4 companion dogs dies from cancer, yet no antibodies are commercially available for use in veterinary oncology. Here we characterize two novel antibodies that bind canine PD-1 with sub-nanomolar affinity as measured by SPR. Both antibodies block the clinically crucial PD-1/PD-L1 interaction in a competitive ELISA assay. Additionally, the antibodies were tested with a broad range of assays including Western Blot, ELISA, flow cytometry, immunofluorescence and immunohistochemistry. The antibodies appear to bind two distinct epitopes as predicted by molecular modeling and peptide phage display. Our study provides new tools for canine oncology research and a potential veterinary therapeutic.

• Klíčová slova
• PD-1, PD-L1, cancer immunotherapy, canine cancer, comparative oncology, immune checkpoint, monoclonal antibody, veterinary oncology,
• MeSH
• antigeny CD274 imunologie   antagonisté a inhibitory   metabolismus   MeSH
• antigeny CD279 * antagonisté a inhibitory   imunologie   MeSH
• epitopy imunologie   MeSH
• inhibitory kontrolních bodů imunologie   farmakologie   MeSH
• lidé MeSH
• monoklonální protilátky * imunologie   MeSH
• nádory imunologie   veterinární   farmakoterapie   MeSH
• nemoci psů imunologie   farmakoterapie   MeSH
• psi * MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi * MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• antigeny CD274 MeSH
• antigeny CD279 * MeSH
• epitopy MeSH
• inhibitory kontrolních bodů MeSH
• monoklonální protilátky * MeSH