Integrating the Universe of Effector and Regulatory Immune Cell Subsets: An Emerging Role of Protein-Glycan Interactions

The immune system has evolved as a highly effective and dynamic cellular network to signal the presence of invading pathogens and growing tumors and initiate a response that is specific for the danger signal; yet maintaining tolerance to self. In the recent years, data from genomics, proteomics and glycomics together with classical genetic approaches (knockout and transgenic experiments) and in vivo imaging technologies revealed a complexity of immune cells and molecules which is higher than anticipated. The diversity of effector and regulatory immune cells is entering a new era, in which their specialization might contribute to the development of novel therapeutic approaches in immunopathology. In this context, recent evidence has shed light to an emerging role of protein-glycan interactions in the regulation of immune cell biology. In this review we will integrate traditional and novel subsets of immune cells and will highlight the relevance of protein-glycan systems in modulating their physiology.