SIALIC ACIDS AS MODULATORS OF ENDOCYTOSIS: THE CASE OF DENDRITIC CELLS pp. 161-175
Authors: M. Guadalupe Cabral, Hélio J. Crespo, A. Rita Piteira, Dário Ligeiro, Paula A.Videira, CEDOC, Departamento de Imunologia, Faculdade de Ciências Médicas, FCM, Universidade Nova de Lisboa, Lisboa, Portugal, and others
Abstract: Sialic acids are a family of sugars, which typically terminate cell surface glycoconjugates. Due to this ubiquitous position, they represent key structural determinants for a number of receptors, and are potential modulators of immune responses, among which endocytosis. Dendritic cells (DC) are professional antigen-presenting cells, crucial for linking innate and immune responses, and have been exploited as therapeutic tools to trigger immunity against tumors or pathogens, or dampen hypersensitivity responses. DCs show a wide capacity to acquire exogenous antigens through different mechanisms, which dictates its immunoregulatory capacity. This chapter focus on the complex role of their highly sialylated cell surface content as modulator of DC endocytosis. In particular it will be presented data that support the evidence that sialylation shortage, while affecting DC maturation, results in opposing effects on macropinocytosis and phagocytosis mechanisms mediated by DCs.