Interferon‑induced transmembrane proteins (IFITMs) are frequently overexpressed in cancer cells, including cervical carcinoma cells, and play a role in the progression of various cancer types. However, their mechanisms of action remain incompletely understood. In the present study, by employing a combination of surface membrane protein isolation and quantitative mass spectrometry, it was comprehensively described how the IFITM1 protein influences the composition of the cervical cancer cell surfaceome. Additionally, the effects of interferon‑γ on protein expression and cell surface exposure were evaluated in the presence and absence of IFITM1. The IFITM1‑regulated membrane and membrane‑associated proteins identified are involved mainly in processes such as endocytosis and lysosomal transport, cell‑cell and cell‑extracellular matrix adhesion, antigen presentation and the immune response. To complement the proteomic data, gene expression was analyzed using reverse transcription‑quantitative PCR to distinguish whether the observed changes in protein levels were attributable to transcriptional regulation or differential protein dynamics. Furthermore, the proteomic and gene expression data are supported by functional studies demonstrating the impact of the IFITM1 and IFITM3 proteins on the adhesive, migratory and invasive capabilities of cervical cancer cells, as well as their interactions with immune cells.

• Klíčová slova
• antigen presentation, cervical cancer, immunosurveillance, interferon‑induced transmembrane proteins, invasion, mass spectrometry, membrane protein, migration, surfaceome,
• MeSH
• buněčná adheze MeSH
• diferenciační antigeny * metabolismus   genetika   MeSH
• fenotyp MeSH
• interferon gama farmakologie   metabolismus   MeSH
• lidé MeSH
• membránové proteiny * metabolismus   genetika   MeSH
• nádorové buněčné linie MeSH
• nádory děložního čípku * patologie   genetika   metabolismus   imunologie   MeSH
• pohyb buněk MeSH
• proteiny vázající RNA * metabolismus   genetika   MeSH
• proteom * MeSH
• proteomika metody   MeSH
• regulace genové exprese u nádorů MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• diferenciační antigeny * MeSH
• IFITM3 protein, human MeSH Prohlížeč
• interferon gama MeSH
• leu-13 antigen MeSH Prohlížeč
• membránové proteiny * MeSH
• proteiny vázající RNA * MeSH
• proteom * MeSH

Interferons (IFNs) are important cytokines that regulate immune responses through the activation of hundreds of genes, including interferon-induced transmembrane proteins (IFITMs). This evolutionarily conserved protein family includes five functionally active homologs in humans. Despite the high sequence homology, IFITMs vary in expression, subcellular localization and function. The initially described adhesive and antiproliferative or pro-oncogenic functions of IFITM proteins were diluted by the discovery of their antiviral properties. The large set of viruses that is inhibited by these proteins is constantly expanding, as are the possible mechanisms of action. In addition to their beneficial antiviral effects, IFITM proteins are often upregulated in a broad spectrum of cancers. IFITM proteins have been linked to most hallmarks of cancer, including tumor cell proliferation, therapeutic resistance, angiogenesis, invasion, and metastasis. Recent studies have described the involvement of IFITM proteins in antitumor immunity. This review summarizes various levels of IFITM protein regulation and the physiological and pathological functions of these proteins, with an emphasis on tumorigenesis and antitumor immunity.

• Klíčová slova
• immunity, interferon-induced transmembrane proteins, stem cells, therapy resistance, tumor immunosurveillance, tumor progression,
• MeSH
• antivirové látky MeSH
• interferony * MeSH
• karcinogeneze MeSH
• lidé MeSH
• membránové proteiny genetika   MeSH
• viry * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antivirové látky MeSH
• interferony * MeSH
• membránové proteiny MeSH

The interferon signalling system elicits a robust cytokine response against a wide range of environmental pathogenic and internal pathological signals, leading to induction of a subset of interferon-induced proteins. We applied DSS (disuccinimidyl suberate) mediated cross-linking mass spectrometry (CLMS) to capture novel protein-protein interactions within the realm of interferon induced proteins. In addition to the expected interferon-induced proteins, we identified novel inter- and intra-molecular cross-linked adducts for the canonical interferon induced proteins, such as MX1, USP18, OAS3, and STAT1. We focused on orthogonal validation of a cohort of novel interferon-induced protein networks formed by the HLA-A protein (H2BFS-HLA-A-HMGA1) using co-immunoprecipitation assay, and further investigated them by molecular dynamics simulation. Conformational dynamics of the simulated protein complexes revealed several interaction sites that mirrored the interactions identified in the CLMS findings. Together, we showcase a proof-of-principle CLMS study to identify novel interferon-induced signaling complexes and anticipate broader use of CLMS to identify novel protein interaction dynamics within the tumour microenvironment.

• MeSH
• HLA antigeny MeSH
• HLA-A antigeny MeSH
• hmotnostní spektrometrie metody   MeSH
• interferony * MeSH
• lidé MeSH
• proteiny * chemie   MeSH
• reagencia zkříženě vázaná chemie   MeSH
• thiolesterasa ubikvitinu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• HLA antigeny MeSH
• HLA-A antigeny MeSH
• interferony * MeSH
• proteiny * MeSH
• reagencia zkříženě vázaná MeSH
• thiolesterasa ubikvitinu MeSH
• USP18 protein, human MeSH Prohlížeč

The IFITM restriction factors play a role in cancer cell progression through undefined mechanisms. We investigate new protein-protein interactions for IFITM1/3 in the context of cancer that would shed some light on how IFITM1/3 attenuate the expression of targeted proteins such as HLA-B. SBP-tagged IFITM1 protein was used to identify an association of IFITM1 protein with the SRSF1 splicing factor and transporter of mRNA to the ribosome. Using in situ proximity ligation assays, we confirmed a predominant cytosolic protein-protein association for SRSF1 and IFITM1/3. Accordingly, IFITM1/3 interacted with HLA-B mRNA in response to IFNγ stimulation using RNA-protein proximity ligation assays. In addition, RT-qPCR assays in IFITM1/IFITM3 null cells and wt-SiHa cells indicated that HLA-B gene expression at the mRNA level does not account for lowered HLA-B protein synthesis in response to IFNγ. Complementary, shotgun RNA sequencing did not show major transcript differences between IFITM1/IFITM3 null cells and wt-SiHa cells. Furthermore, ribosome profiling using sucrose gradient sedimentation identified a reduction in 80S ribosomal fraction an IFITM1/IFITM3 null cells compared to wild type. It was partially reverted by IFITM1/3 complementation. Our data link IFITM1/3 proteins to HLA-B mRNA and SRSF1 and, all together, our results begin to elucidate how IFITM1/3 catalyze the synthesis of target proteins. IFITMs are widely studied for their role in inhibiting viruses, and multiple studies have associated IFITMs with cancer progression. Our study has identified new proteins associated with IFITMs which support their role in mediating protein expression; a pivotal function that is highly relevant for viral infection and cancer progression. Our results suggest that IFITM1/3 affect the expression of targeted proteins; among them, we identified HLA-B. Changes in HLA-B expression could impact the presentation and recognition of oncogenic antigens on the cell surface by cytotoxic T cells and, ultimately, limit tumor cell eradication. In addition, the role of IFITMs in mediating protein abundance is relevant, as it has the potential for regulating the expression of viral and oncogenic proteins.

• Klíčová slova
• interferon (IFN), interferon-induced transmembrane 1 and 3 (IFITM1/3), isoform of serine and arginine-rich splicing factor 1 (SRSF1), mRNA, ribosome,
• MeSH
• diferenciační antigeny metabolismus   MeSH
• HLA-B antigeny * metabolismus   MeSH
• lidé MeSH
• membránové proteiny genetika   metabolismus   MeSH
• messenger RNA genetika   MeSH
• nádory děložního čípku * genetika   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• serin-arginin sestřihové faktory genetika   MeSH
• sestřihové faktory MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• diferenciační antigeny MeSH
• HLA-B antigeny * MeSH
• IFITM3 protein, human MeSH Prohlížeč
• leu-13 antigen MeSH Prohlížeč
• membránové proteiny MeSH
• messenger RNA MeSH
• proteiny vázající RNA MeSH
• serin-arginin sestřihové faktory MeSH
• sestřihové faktory MeSH
• SRSF1 protein, human MeSH Prohlížeč

Interferon-induced transmembrane proteins IFITM1 and IFITM3 (IFITM1/3) play a role in both RNA viral restriction and in human cancer progression. Using immunohistochemical staining of FFPE tissue, we identified subgroups of cervical cancer patients where IFITM1/3 protein expression is inversely related to metastasis. Guide RNA-CAS9 methods were used to develop an isogenic IFITM1/IFITM3 double null cervical cancer model in order to define dominant pathways triggered by presence or absence of IFITM1/3 signalling. A pulse SILAC methodology identified IRF1, HLA-B, and ISG15 as the most dominating IFNγ inducible proteins whose synthesis was attenuated in the IFITM1/IFITM3 double-null cells. Conversely, SWATH-IP mass spectrometry of ectopically expressed SBP-tagged IFITM1 identified ISG15 and HLA-B as dominant co-associated proteins. ISG15ylation was attenuated in IFNγ treated IFITM1/IFITM3 double-null cells. Proximity ligation assays indicated that HLA-B can interact with IFITM1/3 proteins in parental SiHa cells. Cell surface expression of HLA-B was attenuated in IFNγ treated IFITM1/IFITM3 double-null cells. SWATH-MS proteomic screens in cells treated with IFITM1-targeted siRNA cells resulted in the attenuation of an interferon regulated protein subpopulation including MHC Class I molecules as well as IFITM3, STAT1, B2M, and ISG15. These data have implications for the function of IFITM1/3 in mediating IFNγ stimulated protein synthesis including ISG15ylation and MHC Class I production in cancer cells. The data together suggest that pro-metastatic growth associated with IFITM1/3 negative cervical cancers relates to attenuated expression of MHC Class I molecules that would support tumor immune escape.

• Klíčová slova
• CAS9 gene editing, Cervical cancer, IFITM1, Interferon, MHC Class I molecule, SILAC mass spectrometry,
• MeSH
• buněčné linie MeSH
• diferenciační antigeny fyziologie   MeSH
• lidé MeSH
• membránové proteiny fyziologie   MeSH
• MHC antigeny I. třídy metabolismus   MeSH
• nádory děložního čípku metabolismus   MeSH
• proteiny vázající RNA fyziologie   MeSH
• proteosyntéza fyziologie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• diferenciační antigeny MeSH
• IFITM3 protein, human MeSH Prohlížeč
• leu-13 antigen MeSH Prohlížeč
• membránové proteiny MeSH
• MHC antigeny I. třídy MeSH
• proteiny vázající RNA MeSH