A patent review of the antimicrobial applications of lectins: Perspectives on therapy of infectious diseases

Abstract

Patents of lectins with antiviral, antibacterial, and antifungal applications were searched and reviewed.Lectins are proteins that reversibly bind to specific carbohydrates and have the potential for therapy of infectious diseases as biopharmaceuticals, biomedical tools, or in drug design. Given the rising concerns over drug resistance and epidemics, our patent review aims to add information, open horizons, and indicate our view of the future perspectives about the antimicrobial applications of lectins. Patents with Accepted ArticleThis article is protected by copyright. All rights reserved publications until December 2020 were retrieved from Espacenet using defined search terms and Boolean operators. The documents were used to identify the geographical and temporal distribution of the patents, characterize their lectins, and classify and summarize their antiviral, antibiotic, and antifungal applications. Lectins are promising antiviral agents against viruses with epidemics and drug resistance concerns. Mannose-binding lectins were the most suggested antiviral agents since glycans with mannose residues are commonly involved in viral entry mechanisms. They were also applied immobilized onto surfaces to trap viral particles and inhibit their spread and replication. Many patents described the extraction, isolation, amino acid and nucleotide sequences, and expression vectors of lectins with antibiotic and/or antifungal activities in terms of MIC and IC 50 for in vitro assays. The inventions also included lectins as biological tools in nanosensors for antibiotics susceptibility tests, drug delivery systems for the treatment of resistant bacteria, diagnostics of viral diseases, and as a vaccine adjuvant. Although research and development of new medicines is highly expensive, antimicrobial lectins may be worth investments given the emergence of epidemics and drug resistance. For this purpose, less invasive routes should be developed as alternatives to the parenteral administration of biologics. While anti-glycan neutralizing antibodies are difficult to develop due to the low immunogenicity of carbohydrates, lectins can be produced more easily and have a broad-spectrum activity. Protein engineering technologies may make the antimicrobial applications of lectins more successful.

N‐acetyl‐D ‐glucosamine‐binding lectin ( PrLec ) from the serum of healthy blue swimming crab Portunus reticulatus agglutinates Gram‐positive ( Micrococcus luteus ) and Gram‐negative ( Escherichia coli ) bacteria

“…Lectin being one of the critical defence molecules, the more profound understanding of its mechanism can highlight its role in future applications. Many researchers have worked on lectin purification and characterization, which has paved the way for application‐oriented studies such as antimicrobial activity, anticancer, antitumor, etc (Carneiro et al, 2022; Liu et al, 2015). Many studies have been done to date in various organisms yet abounding to be discovered (Gianazza et al, 2021; Viswambari Devi et al, 2010).…”

Plant lectins as prospective antiviral biomolecules in the search for COVID-19 eradication strategies

“…Glycans are the carbohydrate portion of glycoproteins which have crucial roles in the immune system of humans [131] and pathobiology of viral infections [132] . Antiviral lectins can block the entry of virus by binding to glycans from either the virus or host cell [129] . Antiviral lectins can bind to the viral Spike (S) protein of SARS-CoV [116] ; specifically, lectins like mannose/glucose and N-acetylglucosamine (GlcNAc)- specific lectins have been found to inhibit entry of several coronaviruses such as SARS-CoV [133] , [134] , MERS-CoV [135] , and other coronaviruses [136] , [137] .…”

“…On the basis of EC 50 values, the most potential lectins were DLasiL and DSclerL, which showed EC 50 values ranging from 9 nM to 46 nM for HIV-1 and respiratory syncytial virus, respectively; DSclerL, ConBr and ConM showed EC 50 ranging from 0.4 to 6 nM against influenza A virus strain H3N2 and influenza B virus, and DLasiL showed EC 50 of 5 nM against feline coronavirus [128] . In a review study published in August 2021, Carneiro and co-authors have demonstrated antimicrobial applications of patented lectins and listed some patented lectins that exhibited in-vitro antiviral activity [129] (see Table 2 ).…”

Legume Lectins with Different Specificities as Potential Glycan Probes for Pathogenic Enveloped Viruses

“…Depending on their affinity towards surface-exposed glycans of enveloped viruses, plant lectins are considered as potential CBAs useful for combating viral infections, even though little evidence exists to date for their efficacy as relevant therapeutic tools [97,[108][109][110][111][112]. Beyond their possible use as well-adapted tools for the diagnosis of viral infection, the therapeutic use of plant lectins as virus blockers faces practical and functional challenges which mainly concern (1) their large-scale production and (2) their unwanted immunomodulatory properties.…”