Novel mouse monoclonal antibodies specifically recognizing β-(1→3)-D-glucan antigen

Abstract

β-(1→3)-D-Glucan is an essential component of the fungal cell wall. Mouse monoclonal antibodies (mAbs) against synthetic nona-β-(1→3)-D-glucoside conjugated with bovine serum albumin (BSA) were generated using hybridoma technology. The affinity constants of two selected mAbs, 3G11 and 5H5, measured by a surface plasmon resonance biosensor assay using biotinylated nona-β-(1→3)-D-glucan as the ligand, were approximately 11 nM and 1.9 nM, respectively. The glycoarray, which included a series of synthetic oligosaccharide derivatives representing β-glucans with different lengths of oligo-β-(1→3)-D-glucoside chains, demonstrated that linear tri-, penta- and nonaglucoside, as well as a β-(1→6)-branched octasaccharide, were recognized by mAb 5H5. By contrast, only linear oligo-β-(1→3)-D-glucoside chains that were not shorter than pentaglucosides (but not the branched octaglucoside) were ligands for mAb 3G11. Immunolabelling indicated that 3G11 and 5H5 interact with both yeasts and filamentous fungi, including species from Aspergillus , Candida , Penicillium genera and Saccharomyces cerevisiae , but not bacteria. Both mAbs could inhibit the germination of Aspergillus fumigatus conidia during the initial hours and demonstrated synergy with the antifungal fluconazole in killing C . albicans in vitro . In addition, mAbs 3G11 and 5H5 demonstrated protective activity in in vivo experiments, suggesting that these β-glucan-specific mAbs could be useful in combinatorial antifungal therapy.

Immunotherapy against Systemic Fungal Infections Based on Monoclonal Antibodies

“…In addition, protective efficacy in mice vaccinated with a single injection followed by a lethal dose to C. albicans infection was obtained. In this case, a higher survival rate was observed in mice receiving mAb 5H5, which has high affinity and specificity as an IgG3, capable of inducing antibody-dependent cytotoxicity and cell phagocytosis more effectively than IgG1, being able to target mother cells, the main infective propagules [4].…”

“…The increased numbers of immunocompromised hosts, global travel, climate alterations, and the common use of invasive devices have resulted in significant increases in rates of invasive mycoses. The medical mycology community has responded to this crisis by seeking out new approaches to combat these diseases, including through the development of vaccines and monoclonal antibodies (mAbs) [1][2][3][4][5] Recent studies show that systemic mycoses are a leading cause of morbidity and mortality in the US, being responsible for the deaths of more than 1.6 million people [2,6] with annual costs over $7.2 billion dollars [7][8][9]. There is, however, a significantly poorer awareness of the global incidence of systemic mycoses reinforced by the typical lack of transmissibility of fungal diseases [10,11].…”

“…This resistance to antifungal drugs shown by many fungal species is mainly associated with immunocompromised individuals [9]. The toxicity of these medications is an important limitation to their use [4,10,24] and, in order to avert the universal failure in the management of fungal infections, new therapeutic strategies to treat systemic fungal infections are urgently needed [24,25].…”

Monoclonal Antibodies as Tools to Combat Fungal Infections

“…More recently, a mouse-human chimera and a scFv-Fc derived from 2G8 were shown to promote killing of C. albicans by isolated neutrophils and to protect mice in a vulvovaginal model of infection [31]. In 2019, Matveev et al reported that an IgG 1 specific for β-1,3-glucan delayed germination of A. fumigatus conidia and improved survival of mice infected with C. albicans via the intravenous route [32].…”

Development of a novel β-1,6-glucan–specific detection system using functionally-modified recombinant endo-β-1,6-glucanase

“…␤-Glucan is composed of D-glucose units linked by ␤-1,3glycosidic bonds (␤-1,3-D-glucan), which is the most common ␤-glucan structure produced by plants (␤-1,3-/␤-1,4-glucan) (1), bacteria (␤-1,3-glucan) (2), fungi (3), and algae (4) (␤-1,6-/ ␤-1,3-glucan); of interest, ␤-1,3-D-glucan has been at the mainstream of glucan research. In addition, ␤-1,3-D-glucan-specific recognition proteins such as the limulus coagulation factor G in horseshoe crab (5), ␤-1,3-glucan recognition protein in insects (6), dectin-1 (7), and immunoglobulin (8,9) in mammals are discovered in a wide range of species and applied to ␤-1,3-Dglucan-specific detection systems (10 -13). Among these, the most commonly used in the world is factor G from horseshoe crab, a highly-sensitive and rapid assay.…”