Identification of a porcine TLR2-targeting peptide ligands using a cell-based phage display combined with high-throughput sequencing

Author(s):  
Su-Bin An ◽  
Seo-Ho Oh ◽  
Jun-Yeong Lee ◽  
Kwang-Hwan Choi ◽  
Chang-Kyu Lee ◽  
...  

Abstract M cell targeting is one of the critical issues to develop efficient mucosal vaccine design. In this study, peptide ligands with high affinity to porcine TLR2, which is highly expressed in M cells and play an important role in mucosal immune responses in pigs, were identified through the cell-based phage display technique combined with high-throughput sequencing. A random phage-peptide library was applied to the porcine TLR2 overexpressing cell line and total 85, 557 unique peptide sequences were identified from approximately 9.0 × 107 reads after three rounds of both subtractive and non-subtractive biopanning via high-throughput sequencing. Among the unique sequences, three candidate peptide sequences, NAGHLSQ, VPSKPGL, and RANLDGQ, were selected based on their abundance in the third round of biopanning. Consequently, NAGHLSQ showed the highest affinity exclusively to porcine TLR2 compared with other candidates and its binding mechanism was inferred to be directly associated with ligand binding site of the TLR2 through the in vitro competitive analysis. The peptide identified in this research could be used in development of effective porcine mucosal vaccine as an M cell targeting moiety to enhance the transport of antigens into the Peyer's patch via oral route.

2008 ◽  
Vol 295 (1) ◽  
pp. F300-F309 ◽  
Author(s):  
Yu-Jung Lee ◽  
Hyo-Jung Choi ◽  
Jung-Suk Lim ◽  
Ji-Hyun Earm ◽  
Byung-Heon Lee ◽  
...  

Aquaporin-2 (AQP2), the vasopressin-regulated water channel in collecting duct principal cells, plays a key role in the regulation of body water balance. We aimed to isolate high-affinity peptide ligands that bind to immunoisolated AQP2-expressing plasma membrane (PM) or intracellular vesicle (ICV) preparations from rat kidney by the in vitro phage display technique. Immunoblotting revealed that AQP2 was exclusively expressed in the immunoisolated AQP2 membrane fractions (PM and ICV), compared with the nonimmunoisolated or preimmune IgG pulldown rat kidney samples. Moreover, AQP1 or H+-ATPase (B1 subunit) expression was minimal in the immunoisolated AQP2 membrane fractions, indicating the specificity of AQP2 membrane isolation. A phage peptide library based on T7 415-1b phage vector displaying CX7C was constructed. After three rounds of biopanning, seven phage clones of high frequency were selected, which showed high affinity to the AQP2-containing PM or ICV fractions compared with a nonrecombinant T7 insertless phage clone. In contrast, these phage clones showed lower affinity to H+-ATPase-containing fractions. Fluorescein-conjugated peptide labeling was associated with intracellular compartment and PM of primary cultured inner medullary collecting duct cells, relative to absent or very weak labeling with fluorescein-conjugated control peptide. Library analyses demonstrated proteins that had motifs homologous to the peptide ligands, albeit with a high probability of a random match due to short peptide sequences. In summary, we applied the in vitro phage display technique to identify high-affinity peptide ligands to AQP2-expressing membranes. Library analyses identified proteins having homologous motifs, which need to be examined for involvement in AQP2 trafficking and regulation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Débora Ferreira ◽  
Joaquim Barbosa ◽  
Diana A. Sousa ◽  
Cátia Silva ◽  
Luís D. R. Melo ◽  
...  

AbstractTriple-negative breast cancer is the most aggressive subtype of invasive breast cancer with a poor prognosis and no approved targeted therapy. Hence, the identification of new and specific ligands is essential to develop novel targeted therapies. In this study, we aimed to identify new aptamers that bind to highly metastatic breast cancer MDA-MB-231 cells using the cell-SELEX technology aided by high throughput sequencing. After 8 cycles of selection, the aptamer pool was sequenced and the 25 most frequent sequences were aligned for homology within their variable core region, plotted according to their free energy and the key nucleotides possibly involved in the target binding site were analyzed. Two aptamer candidates, Apt1 and Apt2, binding specifically to the target cells with $$K_{d}$$ K d values of 44.3 ± 13.3 nM and 17.7 ± 2.7 nM, respectively, were further validated. The binding analysis clearly showed their specificity to MDA-MB-231 cells and suggested the targeting of cell surface receptors. Additionally, Apt2 revealed no toxicity in vitro and showed potential translational application due to its affinity to breast cancer tissue sections. Overall, the results suggest that Apt2 is a promising candidate to be used in triple-negative breast cancer treatment and/or diagnosis.


2021 ◽  
Vol 22 (11) ◽  
pp. 5513
Author(s):  
Sander Plessers ◽  
Vincent Van Deuren ◽  
Rob Lavigne ◽  
Johan Robben

The combination of phage display technology with high-throughput sequencing enables in-depth analysis of library diversity and selection-driven dynamics. We applied short-read sequencing of the mutagenized region on focused display libraries of two homologous nucleic acid modification eraser proteins—AlkB and FTO—biopanned against methylated DNA. This revealed enriched genotypes with small indels and concomitant doubtful amino acid motifs within the FTO library. Nanopore sequencing of the entire display vector showed additional enrichment of large deletions overlooked by region-specific sequencing, and further impacted the interpretation of the obtained amino acid motifs. We could attribute enrichment of these corrupted clones to amplification bias due to arduous FTO display slowing down host cell growth as well as phage production. This amplification bias appeared to be stronger than affinity-based target selection. Recommendations are provided for proper sequence analysis of phage display data, which can improve motive discovery in libraries of proteins that are difficult to display.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1225
Author(s):  
Jiawen Cao ◽  
Tiantian Fan ◽  
Yanlian Li ◽  
Zhiyan Du ◽  
Lin Chen ◽  
...  

WD40 is a ubiquitous domain presented in at least 361 human proteins and acts as scaffold to form protein complexes. Among them, WDR5 protein is an important mediator in several protein complexes to exert its functions in histone modification and chromatin remodeling. Therefore, it was considered as a promising epigenetic target involving in anti-cancer drug development. In view of the protein–protein interaction nature of WDR5, we initialized a campaign to discover new peptide-mimic inhibitors of WDR5. In current study, we utilized the phage display technique and screened with a disulfide-based cyclic peptide phage library. Five rounds of biopanning were performed and isolated clones were sequenced. By analyzing the sequences, total five peptides were synthesized for binding assay. The four peptides are shown to have the moderate binding affinity. Finally, the detailed binding interactions were revealed by solving a WDR5-peptide cocrystal structure.


2021 ◽  
Author(s):  
Zi-Jian Deng ◽  
Dong-Wen Chen ◽  
Xi-Jie Chen ◽  
Jia-Ming Fang ◽  
Liang Xv ◽  
...  

Abstract Background: Gastric cancer is the fourth most common malignant disease. Both CDK10 and long noncoding RNAs (lncRNAs) have been found to exert biological functions in multiple cancers. However, it is still unclear whether CDK10 represses tumor progression in gastric cancer by reducing potential targeting lncRNAs.Methods: The functions of CDK10 and lncRNA-C5ORF42-5 in proliferation, invasion and migration were assessed by MTS assays, colony formation assays, cell cycle and apoptosis assays, Transwell assays, wound healing assays and animal experiments. We used high-throughput sequencing to confirm the existence of lncRNA-C5ORF42-5 and quantitative real-time PCR was used to evaluate lncRNA expression. Then, with RNA-seq sequencing as well as GO function and KEGG enrichment analysis, we identified the signaling pathways in which lncRNA-C5ORF42-5 was involved in gastric cancer. Finally, western blotting was used to identify the genes regulated by lncRNA-C5ORF42-5.Results: Our results showed that CDK10 is expressed at relatively low levels in gastric cancer cell lines and inhibits the progression of gastric cancer cells both in vitro and in vivo. Next, based on high-throughput sequencing, we identified a novel lncRNA, lncRNA-C5ORF42-5, in the stable CDK10-overexpressing cell line compared with the CDK-knockdown cell line and their controls. Additionally, we confirmed that lncRNA-C5ORF42-5 acts as an oncogene to promote metastasis in gastric cancer in vitro and in vivo. We then ascertained that lncRNA-C5ORF42-5 is a major contributor to the function of CDK10 in gastric cancer metastasis by upregulating lncRNA-C5ORF42-5 to reverse the effects of CDK10 overexpression. Finally, we explored the mechanism by which lncRNA-C5ORF42-5 overexpression affects gastric cancer cells to elucidate whether lncRNA-C5ORF42-5 may increase the activity of the SMAD pathway of BMP signaling and promote the expression of EMT-related proteins, such as E-cadherin. Additionally, overexpression of lncRNA-C5ORF42-5 affected the phosphorylation levels of AKT and ERK.Conclusion: Our findings suggest that CDK10 overexpression represses gastric cancer tumor progression by reducing lncRNA-C5ORF42-5 and hindering activation of the related proteins in metastatic signaling pathways, which provides new insight into developing effective therapeutic strategies in the treatment of metastatic gastric cancer.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13045-e13045
Author(s):  
Chang Gong ◽  
Qun Lin ◽  
Xiaolin Fang ◽  
Wenguo Jiang ◽  
Jun Li ◽  
...  

e13045 Background: Compared to lumial breast cancer, the proporation of triple-negative breast cancer (TNBC) with bone metastases (BMs) is relatively low and few data focusing on the mechanism of the BMs in TNBC are available, Here, we screened that CTNND1 was associated with BMs of TNBC by integrating high-throughput sequencing, and further investigated the role of CTNND1 in BMs of TNBC in vitro. Methods: TNBC tissue samples with only BMs (n = 6) and without any metastasis (n = 10) were tested using high-throughput sequencing and 11 differentially expressed relative genes were identified. We then quantified these 11 genes in normal breast tissue samples (n = 26), TNBC tissue samples with only BMs (n = 10), TNBC tissue samples without any metastasis (n = 88) as well as luminal tissue samples with BMs(n = 10)through qPCR and immunohistochemical staining (IHC). The effects of knocking down CTNND1 on the interaction between TNBC cells and osteoblasts were examined by cell adhesion, transwell migration and matrigel invasion assays. To explorethe role of CTNND1 in mediating bone metastasis in TNBC, we used RNA-sequencing to find out the relative downstream gene CXCR4 and PI3K-AKT-mTOR pathway and verified it in vitro by Western Blotting. Results: Combining our high-throughput sequencing data, qPCR and IHC in clinical tissue samples, we verified that CTNND1 was decreased in TNBC patients with bone metastasis compared to normal tissue and luminal tissue with BMs. Knocking down of CTNND1 in TNBC cells including MDA-MB-231, MDA-MB-468 and BT549 weakened cells adhesion, but facilitated cells migration and invasion. Mechanically, knocking down of CTNND1 upregulated CXCR4 via activating PI3K-AKT-mTOR pathway in TNBC but not luminal and HER2- positive breast cancer cells lines. Conclusions: CTNND1 mediates bone metastasis in triple-negative breast cancer via regulating CXCR4.CTNND1 may serve as a potential predictor of bone metastasis for TNBC patients.


Gut ◽  
2015 ◽  
Vol 66 (3) ◽  
pp. 454-463 ◽  
Author(s):  
Daniele Mennonna ◽  
Cristina Maccalli ◽  
Michele C Romano ◽  
Claudio Garavaglia ◽  
Filippo Capocefalo ◽  
...  

ObjectivePatient-specific (unique) tumour antigens, encoded by somatically mutated cancer genes, generate neoepitopes that are implicated in the induction of tumour-controlling T cell responses. Recent advancements in massive DNA sequencing combined with robust T cell epitope predictions have allowed their systematic identification in several malignancies.DesignWe undertook the identification of unique neoepitopes in colorectal cancers (CRCs) by using high-throughput sequencing of cDNAs expressed by standard cancer cell cultures, and by related cancer stem/initiating cells (CSCs) cultures, coupled with a reverse immunology approach not requiring human leukocyte antigen (HLA) allele-specific epitope predictions.ResultsSeveral unique mutated antigens of CRC, shared by standard cancer and related CSC cultures, were identified by this strategy. CD8+and CD4+T cells, either autologous to the patient or derived from HLA-matched healthy donors, were readily expanded in vitro by peptides spanning different cancer mutations and specifically recognised differentiated cancer cells and CSC cultures, expressing the mutations. Neoepitope-specific CD8+T cell frequency was also increased in a patient, compared with healthy donors, supporting the occurrence of clonal expansion in vivo.ConclusionsThese results provide a proof-of-concept approach for the identification of unique neoepitopes that are immunogenic in patients with CRC and can also target T cells against the most aggressive CSC component.


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