Beta-galactoside-binding lectin that acts as a sensor of membrane damage caused by infection and restricts the proliferation of infecting pathogens by targeting them for autophagy. Detects membrane rupture by binding beta-galactoside ligands located on the lumenal side of the endosome membrane; these ligands becoming exposed to the cytoplasm following rupture.Restricts infection by initiating autophagy via interaction with CALCOCO2/NDP52.Required to restrict infection of bacterial invasion such as S.typhimurium . Also required to restrict infection of Picornaviridae viruses.Has a marked preference for 3'-O-sialylated and 3'-O-sulfated glycans.