Analysis of Galectin Binding to Blood Group Expressing Bacteria

Microbial cell surfaces exhibit a remarkable diversity of complex carbohydrate structures, with most strains producing unique glycan coats distinct from those found on mammalian cells. However, some microbes employ carbohydrate-based molecular mimicry, potentially as a strategy to evade adaptive immune responses. This phenomenon is particularly intriguing in microbes capable of generating ABO blood group-like glycans. While molecular mimicry of host glycans may reduce adaptive immune recognition of specific host-like glycan epitopes expressed by bacteria, innate immune lectins known as galectins have been shown to recognize these glycan structures expressed by bacteria, suggesting that they may contribute to host defense against microbes that utilize molecular mimicry. Flow cytometry using fluorescently labeled galectins provides a powerful tool for examining galectin-bacteria interactions, including engagement of microbes that express blood group-like antigens. Herein, we describe the approaches used for investigating lectin-microbial interactions by flow cytometry.