一般描述

50-250 kDa calculated.

Peripheral lymph node addressin (PNAd) is a mixture of glycoproteins that is expressed on high endothelial venules (HEV) and is required for lymphocyte homing. It is shown to be a ligand for CD62L (L-selectin) that is expressed on the surface of naïve and central memory T cells. PNAd is a sulfated and fucosylated glycoprotein recognized by the prototypic monoclonal antibody, MECA-79. Naïve T cells use PNAd to traffic into lymphoid organs in non-mucosal tissue sites. The interaction of PNAd with CD62L receptor is involved in tethering and rolling of lymphocytes along HEV in lymphoid tissues. Regulated appearance of PNAd+ HEVs is found during ontogeny of lymphoid tissues as well as in chronic inflammatory conditions. PNAd+ HEVs are reported to appear 24-48 h after birth in mouse peripheral lymph nodes and persist throughout life to support recirculation of lymphocytes. In humans PNAd+ HEVs are detected in fetal peripheral lymph nodes. PNAd+ HEVs are also shown to be present in several chronic inflammatory conditions, including thyroiditis, ulcerative colitis, psoriasis, rheumatoid synovitis, and cutaneous lymphomas. In murine models of inflammation, PNAd+ HEV-like vessels develop and these vessels are found to support lymphocyte recruitment. Studies on cancer in murine models and in humans have identified PNAd as a biomarker of improved disease prognosis and blockade of PNAd or its ligand, L-selectin, is shown to abrogate protective antitumor immunity in murine models. (Ref.: Sinha, RK et al. (2006). Vet. Immunol. Immunopathol. 110 (1-2): 97-108).