Evaluation of the immunomodulatory potential of polysaccharides isolated from microalgae

• Grant number: 21/13969-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2022
• End date: June 30, 2024
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: João Roberto Oliveira do Nascimento
• Grantee: Leandro Almeida Domiciano de Andrade
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/07914-8 - FoRC - Food Research Center, AP.CEPID
• Associated scholarship(s): 22/08480-0 - Unraveling the structure-function relationship between edible microalgae non-starch polysaccharides and their effects on immune cells, BE.EP.DR

Abstract

Some non-starch polysaccharides (PNA), which are undigested mainly components of dietary fiber, can modulate immune function and contribute to good health condition. Although the intestinal microbiota metabolizes many PNA, some can directly interact with Pattern Recognition Receptors (PRR) of intestinal immune cells, recognizing molecular structures related to pathogens. Thus, these macromolecules can act as Biological Response Modifiers (BRM), activating the immune system through antigen-presenting cells, such as macrophages, inducing responses such as increased production of cytokines and chemokines, reactive oxygen (ROS) and nitrogen species and phagocytic activity. Immunomodulatory activities of several types of PNA have already been demonstrated, however, little is known about the immunomodulatory potential of microalgal polysaccharides. Microalgae are single-celled eukaryotic organisms with photosynthetic capacity that thrive in sweet or saline aquatic environments. Cultivation of microalgae has aroused interest as a clean technology that enables the treatment of tailings and residues and provides the generation of products and by-products of high nutritional value from the high yield of biomass without the use of electricity the use of water not drinkable. In addition, microalgae polysaccharides are of technological interest, as they can be used in food formulation as anti-caking agents, body agents, emulsifiers and gelling agents, among other functions. On the other hand, knowledge about its immunomodulatory potential is limited, in spite of the unexplored diversity of microalgae. Therefore, we aim to extract, purify and characterize non-starch polysaccharides from microalgae and evaluate their immunomodulatory action in macrophage. Culture of microalgae will be conducted in a photo-bioreactor to obtain biomass, followed by purification of PNA and characterization of monosaccharide units and chemical bonds. After removal of endotoxins, cell viability will be accessed to establish the proper amounts of PNA for testing cytokine and nitric oxide in cell culture supernatants and phagocytosis. At the end of the project, we expect to identify microalgae polysaccharides capable of modulating the function of macrophages, which may contribute to the use of these microorganisms as sources of food ingredients of technological and functional interest. (AU)