Figure 1. Strategy for mapping human lectin-glycome Interaction. In-house prepared recombinant human lectins are incubated with mutant cells of the human glycome pathway. Changes in lectin binding profiles between wildtype and mutant cells provide insight into a connection between lectins binding and physiological cell surface glycome remodeling from a tractable genetic background. This information allows a quick search for human lectins sensitive to a physiological cell status and identification of biomarkers or drug candidates. We can engineer the lectin of interest using our RIFFLIE technique (Recombinational Incision For Functional Lead Evolution)  for enhanced cellular functions. 

Figure 2. Profiling human cell glycome using human lectins. Fixed K562 cells were stained by FITC-labeled recombinant lectins, and the mixture was subjected to flow cytometry analysis on a CytoFlexS Flow Cytometer. FITC-labeled BSA was used as a background control. The histogram represents mean fluorescence intensity (MFI) values plus error from two independent experiments.

We accessed human lectin-glycome interaction through a matrix of binding assay between our Human Glycoprofile Collection and our Human Lectin Collection. The results provide insight to genetically linked information of changes in lectin-glycome interactions caused by disrupting glycogenes. These results support further applications of this platform on human lectin-based biomarker discovery, human glycoprofile-based cell typing, human lectin-assisted live cell enrichment, therapeutic target discovery and validation, and discovery of glycan-receptor pairs.

Figure 4. Titration of galectin-1 allowed K562 sialylation state investigation. (A) Investigate sialylation-dependent binding property by titrating lectin concentration. The K562 cells were fixed by paraformaldehyde solution and labeled with DyLight405 prior to use. Desialylation of K562 was achieved by treatment with Vibrio cholerae sialidase. Channel BV421 and FITC+ were used for gating K562 cells and FITC-labeled galectin-1 binding, respectively. 

(B) Validating K562 desialylation state by commercially available lectins, PNA and SNA. FITC-labeled PNA and SNA were used for validating K562 desialylation. FITC+ cells were counted by gating against a FITC-labeled BSA background.

Recombinant human lectins are versatile tools in probing physiologically relevant glycoprofiles, enriching target cells by specific glycosylated states, and more recently in helping therapeutic development through the glyco-immunomodulatory mechanisms. Here, we aimed to establish a curated collection of recombinant human lectins as a commercial source of such an array of human lectins. We validate its application through our Human Glycoprofile Collection at GlycoGenetics, showing the versatility of Human Lectin Collection to decipher the physiological meanings of a broad spectrum glycome changes.