Generation of a novel affibody molecule targeting Chlamydia trachomatis MOMP

Abstract

Chlamydia trachomatis (C. trachomatis) is the leading cause of preventable blindness worldwide and the most prevalent cause of bacterial sexually transmitted diseases. At present, there is no available vaccine, and recurrences after antibiotics treatment are substantial problems. Major outer membrane protein (MOMP) accounts for 60% of the outer mass of C. trachomatis, functioning as trimeric porin, and it is highly antigenic. Therefore, MOMP is the most promising candidate for vaccine developing and target therapy of Chlamydia. Affibody, a new class of affinity ligands derived from the Z-domain in the binding region of Staphylococcus aureus protein A, has been the focus of researchers as a viable alternative to antibodies. In this study, the MOMP-targeted affibody molecule (ZMOMP:461) was screened by phage-displayed peptide library. Further, the affinity and specificity were characterized by surface plasmon resonance (SPR) and Western blot. Immunofluorescence assay (IFA) indicated that the MOMP-binding affibody could recognize native MOMP in HeLa229 cells infected C. trachomatis. Immunoprecipitation assay confirmed further that ZMOMP:461 molecule specifically recognizes the epitope on relaxed trimer MOMP. Our findings provide strong evidence that affibody molecule (ZMOMP:461) serves as substitute for MOMP antibody for biological applications and has a great potential for delivering drugs for target therapy. Key points • We screened a novel affibody molecule ZMOMP:461 targeting Chlamydia trachomatis MOMP. • ZMOMP:461 recognizes the recombinant and native MOMP with high affinity and specificity. • ZMOMP:461 could be internalized into live target cells.

Novel Affibody Molecules Specifically Bind to SARS-CoV-2 Spike Protein and Efficiently Neutralize Delta and Omicron Variants

“… b The interaction sites of Z RBMFP with SARS-CoV-2 spike protein (RBM) overlapped (bold face) and sterically hindered (underlined) the ACE2 binding. The mutation sites of RBM in Delta variants are L452R and T478K; in Omicron, variants are N440K, G446S, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y, and Y505H ( 41 ). c Binding sites of ACE2 receptor with RBM of SARS-CoV-2 Prototype, Delta, and Omicron.…”

“…More than 40 affibodies have been developed for potential targeted therapy or imaging diagnosis candidates. Among them, the affibodies could target the pathogenic proteins, including the HIV-1 envelope glycoprotein 120 (HIV-1 gp120) ( 36 ), Epstein-Barr virus latent membrane protein 2 (EBV-LMP) ( 37 ), human papillomavirus (HPV) type 16 and 18 E7 proteins ( 34 , 38 – 40 ), Chlamydia trachomatis major outer membrane proteins (Ct-MOMP) ( 41 ), and HPV16 E6 protein ( 38 ). Moreover, the most promising affibody-targeted HER-2 has been approved in clinical usage for years and shows great potential for in vivo molecular imaging applications ( 42 ).…”

The HPV16E7 Affibody as a Novel Potential Therapeutic Agent for Treating Cervical Cancer Is Likely Internalized through Dynamin and Caveolin-1 Dependent Endocytosis

“…Some therapeutic affibodies have now entered preclinical and clinical trials for cancer treatment [ 5 ]. Recently, several affibodies using intracellular proteins as targets show great potential in cancer and other disease treatment [ 6 , 7 , 8 , 9 , 10 , 11 ]. We have previously developed the affibody Z HPV16E7 384 as a cervical cancer therapeutic agent [ 6 , 7 ].…”

“…Several therapeutic affibodies have now entered preclinical and clinical trials for cancer treatment [ 5 ]. In more recent studies, several affibodies that target intracellular proteins show great potential in cancer and other disease therapy, which include the affibodies targeting HPV16 E6 or E7 for cervical cancer, those targeting the EBV LMP1 C-terminal domain or LMP2A N-terminal domain for nasopharyngeal carcinoma, and those targeting Chlamydia trachomatis MOMP for Chlamydia trachomatis [ 6 , 7 , 8 , 9 , 10 , 11 ]. However, a key question that remains to be answered is whether and how the affibodies enter the target cells to interact with intracellular target proteins, leading to the inhibition of the target cell proliferation and finally to destroy the target cells.…”

Chlamydia trachomatis: quest for an eye-opening vaccine breakthrough

“…MOMP of C. trachomatis constitutes almost 60% of its outer mass and functions as an antigenic trimeric porin [51]. This role makes MOMP a fantastic potential vaccine candidate, which has been shown to generate novel MOMP-binding antibody in C. trachomatis infected HeLa229 cells; however, it is yet to reach preclinical trials.…”