Brianna Dalesandro

Cancer Res. 2023 Jan 18;83(2):167-169. doi: 10.1158/0008-5472.CAN-22-3350.

ABSTRACT

While the goal of most anticancer treatments is to kill cancer cells, some therapies halt cancer progression by inducing cancer cell differentiation. For example, retinoic acid induces neuroblastoma cell differentiation in vitro and is used as maintenance therapy for children with high-risk neuroblastoma. A new study by Jiang and colleagues has revealed the mitochondrial uncoupler niclosamide ethanolamine (NEN) induces neuroblastoma cell differentiation in vitro and slows neuroblastoma tumor growth in vivo. Mitochondrial uncoupler molecules alter cell metabolism by forcing cells to "burn" more nutrients, resulting in a switch from anabolic to catabolic metabolism. NEN-induced neuroblastoma cell differentiation was associated with disruption of Warburg metabolism, epigenetic remodeling, and downregulation of key oncogenic drivers of neuroblastoma development, including MYCN. NEN is currently used as an antiparasitic worm treatment and is safe to use in children but has poor pharmacokinetic properties. However, derivatives of NEN and structurally distinct uncouplers that have improved pharmacokinetic properties are in development. Results of this study ignite the idea that mitochondrial uncouplers could be used as differentiating agents and expand the pharmacotherapy toolkit to treat cancer, including neuroblastoma. See related article by Jiang et al., p. 181.

PMID:36651076 | DOI:10.1158/0008-5472.CAN-22-3350

Curr Opin Microbiol. 2023 Apr;72:102261. doi: 10.1016/j.mib.2022.102261. Epub 2023 Jan 11.

ABSTRACT

Streptococcus pneumoniae is the most common cause of community-acquired pneumonia, and one of the main pathogens responsible for otitis media infections in children. Amoxicillin (AMX) is a broad-spectrum β-lactam antibiotic, used frequently for the treatment of bacterial respiratory tract infections. Here, we discuss the pneumococcal response to AMX, including the mode of action of AMX, the effects on autolysin regulation, and the evolution of resistance through natural transformation. We discuss current knowledge gaps in the synthesis and translocation of peptidoglycan and teichoic acids, major constituents of the pneumococcal cell wall and critical to AMX activity. Furthermore, an outlook of AMX resistance research is presented, including the development of natural competence inhibitors to block evolution via horizontal gene transfer, and the use of high-throughput essentiality screens for the discovery of novel cotherapeutics.

PMID:36638546 | DOI:10.1016/j.mib.2022.102261

Front Microbiol. 2023 Jan 5;13:1068251. doi: 10.3389/fmicb.2022.1068251. eCollection 2022.

ABSTRACT

Staphylococcus aureus, which lacks pili and flagella, is nonmotile. However, it hitchhikes motile bacteria, such as Pseudomonas aeruginosa, to migrate in the environment. This study demonstrated that the hitchhiking motility of S. aureus SA113 was reduced after the tagO, which encodes an enzyme for wall teichoic acids (WTA) synthesis, was deleted. The hitchhiking motility was restored after the mutation was complemented by transforming a plasmid expressing TagO into the mutant. We also showed that adding purified lipopolysaccharide (LPS) to a culture that contains S. aureus SA113 and P. aeruginosa PAO1, reduced the movement of S. aureus, showing that WTA and LPS are involved in the hitchhiking motility of S. aureus. This study also found that P. aeruginosa promoted the movement of S. aureus in the digestive tract of Caenorhabditis elegans and in mice. In conclusion, this study reveals how S. aureus hitchhikes P. aeruginosa for translocation in an ecosystem. The results from this study improve our understanding on how a nonmotile pathogen moves in the environment and spreads in animals.

PMID:36687638 | PMC:PMC9849799 | DOI:10.3389/fmicb.2022.1068251

Mol Pharm. 2023 Feb 6;20(2):853-874. doi: 10.1021/acs.molpharmaceut.2c00821. Epub 2023 Jan 25.

ABSTRACT

Small-molecule drugs have been employed for years as therapeutics in the pharmaceutical industry. However, small-molecule drugs typically have short in vivo half-lives which is one of the largest impediments to the success of many potentially valuable pharmacologically active small molecules. The undesirable pharmacokinetics and pharmacology associated with some small molecules have led to the development of a new class of bioconjugates known as chemically programmed antibodies (cPAbs). cPAbs are bioconjugates in which antibodies are used to augment small molecules with effector functions and prolonged pharmacokinetic profiles, where the pharmacophore of the small molecule is harnessed for target binding and therefore biological targeting. Many different small molecules can be conjugated to large proteins such as full monoclonal antibodies (IgG), fragment crystallizable regions (Fc), or fragment antigen binding regions (Fab). In order to successfully and site-specifically conjugate small molecules to any class of antibodies (IgG, Fc, or Fab), the molecules must be derivatized with a functional group for ease of conjugation without altering the pharmacology of the small molecules. In this Review, we summarize the different synthetic or biological methods that have been employed to produce cPAbs. These unique chemistries have potential to be applied to other fields of antibody modification such as antibody drug conjugates, radioimmunoconjugates, and fluorophore-tagged antibodies.

PMID:36696533 | DOI:10.1021/acs.molpharmaceut.2c00821

J Med Chem. 2023 Jan 12;66(1):553-576. doi: 10.1021/acs.jmedchem.2c01489. Epub 2022 Dec 22.

ABSTRACT

Rising infection rates with multidrug-resistant pathogens calls for antibiotics with novel modes of action. Herein, we identify the inner membrane protein TonB, a motor of active uptake in Gram-negative bacteria, as a novel target in antimicrobial therapy. The interaction of the TonB box of outer membrane transporters with TonB is crucial for the internalization of essential metabolites. We designed TonB box peptides and coupled them with synthetic siderophores in order to facilitate their uptake into bacteria in up to 32 synthetic steps. Three conjugates repressed the growth of Pseudomonas aeruginosa cells unable to produce their own siderophores, with minimal inhibitory concentrations between 0.1 and 0.5 μM. The transporters mediating uptake of these compounds were identified as PfeA and PirA. The study illustrates a variant of cellular suicide where a transporter imports its own inhibitor and demonstrates that artificial siderophores can import cargo with molecular weights up to 4 kDa.

PMID:36548006 | PMC:PMC9841981 | DOI:10.1021/acs.jmedchem.2c01489

AMB Express. 2023 Jan 12;13(1):4. doi: 10.1186/s13568-023-01509-y.

ABSTRACT

Here, we developed a genetically modified lactic acid bacteria (gmLAB) that produces green fluorescent protein (GFP)-conjugating, anti-programmed death-ligand 1 (PD-L1) single-chain variable fragments (scFv) for use as an anti-cancer device that targets immune checkpoint molecules. Since PD-L1 plays a key role as an immune checkpoint molecule in the tumor microenvironment, inhibition and detection of PD-L1 are important in cancer research. The anti-PD-L1 scFv was designed based on atezolizumab, a humanized IgG1 monoclonal antibody, and integrated into a lactococcal GFP gene expression vector. Gene expression from the constructed gmLAB was confirmed by western blotting and GFP fluorescence. The ability of GFP-conjugating anti-PD-L1 scFv against the target antigen, PD-L1 protein, was shown using an enzyme-linked immunosorbent assay. Finally, the ability to recognize PD-L1-expressing tumor-cell lines was confirmed using flow cytometry and fluorescence microscopy. Our results suggest that the gmLAB could be applied to in vivo imaging in cancer as an affordable diagnostic/treatment tool.

PMID:36635518 | PMC:PMC9837357 | DOI:10.1186/s13568-023-01509-y

Protein Expr Purif. 2023 Mar;203:106210. doi: 10.1016/j.pep.2022.106210. Epub 2022 Dec 4.

ABSTRACT

Many efforts have been made around the world to combat SARS-CoV-2. Among these are recombinant antibodies considered to be suitable as an alternative for some diagnostics/therapeutics. Based on their importance, this study aimed to investigate the expression, purification, and efficiency of a new potent recombinant scFv in the E. coli BL21 (DE3) system. The expression studies were performed after confirming the scFv cloning into the pET28a vector using specific PCRs. After comprehensive expression studies, a suitable strategy was adopted to extract and purify periplasmic proteins using Ni²⁺-NTA resin. Besides the purified scFv, the crude bacterial lysate was also used to develop a sandwich ELISA (S-ELISA) for the detection of SARS-CoV-2. The use of PCR, E. coli expression system, western blotting (WB), and S-ELISA confirmed the functionality of this potent scFv. Moreover, the crude bacterial lysate also showed good potential for detecting SARS-CoV-2. This could be decreasing the costs and ease its utilization for large-scale applications. The production of high-quality recombinant proteins is essential for humankind. Moreover, with attention to the more aggressive nature of SARS-CoV-2 than other coronaviruses, the development of an effective detection method is urgent. Based on our knowledge, this study is one of the limited investigations in two fields: (1) The production of anti-SARS-CoV-2 scFv using E. coli [as a cheap heterologous host] in relatively high amounts and with good stability, and (2) Designing a sensitive S-ELISA for its detection. It may also be utilized as potent therapeutics after further investigations.

PMID:36473692 | PMC:PMC9719605 | DOI:10.1016/j.pep.2022.106210

Angew Chem Int Ed Engl. 2023 Feb 20;62(9):e202214659. doi: 10.1002/anie.202214659. Epub 2023 Jan 23.

ABSTRACT

Chemical immunotherapeutic strategies including Antibody Recruiting Molecules (ARMs - bivalent small molecules containing an antibody-binding domain (ABD) and a target-binding domain (TBD)) direct immune-mediated clearance of diseased cells. Anti-cancer ARM function relies on high tumor antigen valency, limiting function against lower antigen expressing tumors. To address this limitation, we report a tunable multivalent immune recruitment (MIR) platform to amplify/stabilize antibody recruitment to cells with lower antigen valencies. An initial set of polymeric ARMs (pARMs) were synthesized and screened to evaluate ABD/TBD copy number, ratio, and steric occlusion on specific immune induction. Most pARMs demonstrated simultaneous high avidity binding to anti-dinitrophenyl antibodies and prostate-specific membrane antigens on prostate cancer. Optimized pARMs mediated enhanced anti-cancer immune function against lower antigen expressing target cells compared to an analogous ARM.

PMID:36577087 | DOI:10.1002/anie.202214659