The status quo and evolution of glycoconjugates for cancer immunotherapy

Glycans and glycoconjugates play a significant role in nearly all aspects of living organisms from birth through development to demise. For more than half a century, the aberrant glycosylation profiles on tumor cells have been discussed. However, in the past few decades scientists have validated how these modified glycans influence cancer development, progression and metastasis through bypassing immune surveillance and creating an immunosuppressive milieu in the tumor microenvironment. Although advancements in cancer immunotherapy have shown promise, it has only been able to enhance the overall survival of a small group of patients. Certain types of cancer remain undiagnosed and untreated until very late stages, due to the limited understanding of complex tumor immune resistance. The understanding and use of glycans and glycoconjugates help researchers to work towards broadening the benefits of cancer immunotherapy to a larger population. Many glycans and glycoconjugates have made their way to clinical trials but still the full potential of glycan-based materials has not been entirely harnessed. This comprehensive review outlines major developments in the field of glycoconjugate mediated cancer immunotherapy, with special emphasis on the most recent developments. While covering a wide range of glycan categories, attempts have been made to draw correlations between glycoconjugate structure and the primary immune response elicited by each of those glycan categories.