Involvement of CD147 on multidrug resistance through the regulation of P-glycoprotein expression in K562/ADR leukemic cell line

Comparative assessment of different anti-CD147/Basigin 2 antibodies as a potential therapeutic anticancer target by molecular modeling and dynamic simulation

Cluster of differentiation 147 (CD147) is an attractive target for anticancer therapy since it is pivotal in developing and progressing several of malignant tumors in the context of its high expression levels. Although anti-CD147 antibodies by different laboratories are designed for the Ig-like domains of CD147, there is a demand to provide priority among these anti-CD147 antibodies for developing of therapeutic anti-CD147 antibody before experimental validations. This study uses molecular docking and dynamic simulation techniques to compare the binding modes and affinities of nine antibody models against the Ig-like domains of CD147. After obtaining the model antibodies by homology modeling via Robetta, we predicted the CDRs of nine antibodies and the epitopes of CD147 to reach more accurate results for antigen affinity in molecular docking. Next, from HADDOCK 2.4., we meticulously handpicked the most superior model clusters (Z-Score: - 2.5 to - 1.2) and identified that meplazumab had higher affinities according to the success rate as the percentage of a scoring scale. We achieved stable simulations of CD147-antibody interaction. Our outcomes hold hypothetical importance for further experimental cancer research on the design and development of the relevant model antibodies.

Super-Resolution Microscopy Reveals Local Accumulation of Plasma Membrane Gangliosides at Neisseria meningitidis Invasion Sites

Neisseria meningitidis (meningococcus) is a Gram-negative bacterium responsible for epidemic meningitis and sepsis worldwide. A critical step in the development of meningitis is the interaction of bacteria with cells forming the blood-cerebrospinal fluid barrier, which requires tight adhesion of the pathogen to highly specialized brain endothelial cells. Two endothelial receptors, CD147 and the β2-adrenergic receptor, have been found to be sequentially recruited by meningococci involving the interaction with type IV pilus. Despite the identification of cellular key players in bacterial adhesion the detailed mechanism of invasion is still poorly understood. Here, we investigated cellular dynamics and mobility of the type IV pilus receptor CD147 upon treatment with pili enriched fractions and specific antibodies directed against two extracellular Ig-like domains in living human brain microvascular endothelial cells. Modulation of CD147 mobility after ligand binding revealed by single-molecule tracking experiments demonstrates receptor activation and indicates plasma membrane rearrangements. Exploiting the binding of Shiga (STxB) and Cholera toxin B (CTxB) subunits to the two native plasma membrane sphingolipids globotriaosylceramide (Gb3) and raft-associated monosialotetrahexosylganglioside GM1, respectively, we investigated their involvement in bacterial invasion by super-resolution microscopy. Structured illumination microscopy (SIM) and direct stochastic optical reconstruction microscopy (dSTORM) unraveled accumulation and coating of meningococci with GM1 upon cellular uptake. Blocking of CTxB binding sites did not impair bacterial adhesion but dramatically reduced bacterial invasion efficiency. In addition, cell cycle arrest in G1 phase induced by serum starvation led to an overall increase of GM1 molecules in the plasma membrane and consequently also in bacterial invasion efficiency. Our results will help to understand downstream signaling events after initial type IV pilus-host cell interactions and thus have general impact on the development of new therapeutics targeting key molecules involved in infection.

The small-molecule compound AC-73 targeting CD147 inhibits leukemic cell proliferation, induces autophagy and increases the chemotherapeutic sensitivity of acute myeloid leukemia cells

CD147 is a transmembrane glycoprotein with multiple functions in human healthy tissues and diseases, in particular in cancer. Overexpression of CD147 correlates with biological functions that promote tumor progression and confers resistance to chemotherapeutic drugs. In contrast to solid tumors, the role of CD147 has not been extensively studied in leukemia. Understanding whether CD147 represents a new hematologic target and whether its inhibitor AC-73 may be used in leukemia therapy may reveal an alternative treatment strategy in patients with acute myeloid leukemia (AML). We analyzed CD147 expression and function in hematopoietic progenitor cells from normal cord blood, in several leukemic cell lines and in primary leukemic blasts obtained from patients with AML. We investigated the effects of AC-73, used alone or in combination with arabinosylcytosine (Ara-C) and arsenic trioxide (ATO), on leukemic cell proliferation. We demonstrated that CD147 overexpression promotes leukemic cell proliferation. We showed that AC-73 exhibits a potent growth inhibitory activity in leukemic cells, by inhibiting the ERK/STAT3 activation pathway and activating autophagy. We demonstrated that AC-73 exerts an anti-proliferative effect additive to chemotherapy by enhancing leukemic cell sensitivity to Ara-C-induced cytotoxicity or to ATO-induced autophagy. We also reported CD147 expression in the fraction of leukemic blasts expressing CD371, a marker of leukemic stem cells. Altogether, our study indicates CD147 as a novel potential target in the treatment of AML and AC-73 as an anti-proliferative drug and an inducer of autophagy in leukemic cells to use in combination with chemotherapeutic agents.

Identification of an HLA-A2-restricted CD147 epitope that can induce specific CTL cytotoxicity against drug resistant MCF-7/Adr cells

Cluster of differentiation (CD)147 is highly expressed in drug-resistant tumor cell lines and is involved in the formation of tumor drug resistance. Therefore, immunotherapy utilizing CD147 epitope peptides is a promising approach for the elimination of drug-resistant tumor cells. However, like most tumor-associated antigens (TAAs), CD147 belongs to the autoantigen category, and T cells that recognize high affinity, immunodominant epitopes from autoantigens are deleted though thymic negative selection. Furthermore, wild-type autoantigen peptides cannot effectively activate and expand T lymphocytes with lower affinity T cell receptors in vivo. However, mutations of TAA peptides have been demonstrated to increase the affinity of major histocompatibility complex molecules and their binding to T cell receptor molecules, leading to activation of T lymphocytes in vitro. In the present study, a high-affinity point mutation peptide, CD147_126-134L2, was predicted by the human leukocyte antigen (HLA) binding prediction algorithm and its affinity was testified using a T2 binding assay. In addition, when peptide-specific cytotoxic T lymphocytes (CTLs) were stimulated with dendritic cells loaded with the CD147_126-134L2 peptide under HLA-A*02:01 restriction, interferon-γ release and cytotoxicity assays showed that peptide-specific CTLs effectively cross-recognized and lysed T2 target cells loaded either with the wild-type (CD147_126-134) or mutated peptide (CD147_126-134L2). Moreover, the CD147_126-134L2 peptide-specific CTLs exerted strong cytotoxic activity against drug-resistant MCF-7/Adr cells, which express a high level of CD147 and are HLA-A*02:01-positive, but not against normal MCF-7 cells. Thus, this suggests that the wild-type peptide (CD147_126-134) is naturally presented on HLA-A*02:01 of CD147-expressing MCF-7/Adr cells and is cross-recognized by CTLs. In conclusion, an HLA-A*02:01-restricted CD147-point mutant epitope peptide was identified that induces CTLs to efficiently lyse drug-resistant MCF-7 cells that highly express CD147. Therefore, this immunotherapeutic approach should be explored as a potential treatment for drug-resistant tumors.