Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Preferentially binds to alpha-2,3- or alpha-2,6-linked sialic acid (PubMed:20038598). The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface. In the immune response, seems to act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatase(s) via their SH2 domain(s) that block signal transduction through dephosphorylation of signaling molecules (By similarity). Involved in negative regulation of B-cell antigen receptor signaling and specifically acts on B1 cells to inhibit Ca(2+) signaling, cellular expansion and antibody secretion (PubMed:17572677). The inhibition of B cell activation is dependent on PTPN6/SHP-1 (PubMed:23836061). In association with CD24 may be involved in the selective suppression of the immune response to danger-associated molecular patterns (DAMPs) such as HMGB1, HSP70 and HSP90 (PubMed:19264983). In association with CD24 may regulate the immune repsonse of natural killer (NK) cells (By similarity). Plays a role in the control of autoimmunity (PubMed:20200274). During initiation of adaptive immune responses by CD8-alpha(+) dendritic cells inhibits cross-presentation by impairing the formation of MHC class I-peptide complexes. The function seems to implicate recruitment of PTPN6/SHP-1, which dephosphorylates NCF1 of the NADPH oxidase complex consequently promoting phagosomal acidification (PubMed:27548433). (Microbial infection) During infection by RNA viruses inhibits DDX58/RIG-I signaling in macrophages by promoting its CBL-dependent ubiquitination and degradation via PTPN11/SHP-2. Interacts with PTPN6/SHP-1 upon phosphorylation. Interacts with NCF1 (PubMed:27548433). Interacts with CD24; the probable CD24:SIGLEC10 complex is proposed to inhibit HGMB1-mediated tissue damage immune response. Interacts with HMGB1; the interaction is dependent on CD24 (PubMed:19264983). Associates with membrane IgM on the B cell surface (PubMed:24790146). Interacts with DDX58, CBL and PTPN11 (PubMed:23374343). Expressed in B cells with high levels in pre-B cells and B1a cells of the peritoneal cavity. Contains 1 copy of a cytoplasmic motif that is referred to as the immunoreceptor tyrosine-based inhibitor motif (ITIM). This motif is involved in modulation of cellular responses. The phosphorylated ITIM motif can bind the SH2 domain of several SH2-containing phosphatases. Phosphorylation of Tyr-659 is involved in binding to PTPN6. Cd22/Siglec10 double-deficient mice develop autoimmune disease, which is not observed in single-deficient mice. Belongs to the immunoglobulin superfamily. SIGLEC (sialic acid binding Ig-like lectin) family.