Este trabalho foi apoiado por doações do Conselho Nacional de Desenvolvimento Científico e Tecnológico– CNPq, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES, Ministério da Ciência e Tecnologia - MCT, Ministério da Saúde-MS, Programa Rede Nordeste de Biotecnologia – RENORBIO / CNPq, Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico– FUNCAP e Centro de Pesquisas Aggeu Magalhães / FIOCRUZMarine algae can serve as sources of bioactive compounds and currently have been shown their potential biological and pharmaceutical applications. Marine algae lectins have been shown to be effective at controlling inflammatory processes. This work aimed to analyze the immunostimulatory properties of lectins from the marine algae Solieria filiformis (SfL), Pterocladiella capillacea (PcL) and Caulerpa cupressoides (CcL). This analysis was performed on BALB/c mouse splenocytes by measuring cytokine and nitric oxide production and cellular damage using tests of cytotoxicity and cell viability. These lectins were not cytotoxic (1-100 μg/mL), and were not able to induce IFN-γ and IL-2 production. IL- 10 production was induced at high levels by all lectins tested. Treatment with SfL induced IL-6 production at higher levels at all experimental times, whereas treatment with PcL and CcL induced higher levels only in 24 and 72 h. Treatment with SfL did not result in nitrite oxide production, whereas treatment with PcL or CcL was able to induce nitrite release at high levels (after 24, 48 and 72 h). Lesser cellular damage (5%) was observed in splenocytes treated with these lectins (10 μg/mL). Thus, the lectins from these algae were not cytotoxic, promoted increased in cell viability and induced Th2 immune responses in mouse splenocytes, indicating that they have anti-inflammatory effects.2050-01-01