Cellular Antigens

Human immunodeficiency virus type 1 (HIV-1) entry into target cells is directed by the envelope (Env) glycoproteins, which are present on the surface of HIV-1 virion or infected cells in the form of trimers consisting of gp120/gp41 complexes. The surface subunit, gp120, initiates the entry process by interacting sequentially with the CD4 receptor and a co-receptor CCR5 or CXCR4, thereby inducing a conformational change that allows the transmembrane (TM) gp41 subunit to mediate fusion between viral and target cell membranes.

Periostin is a matricellular protein, i.e. an extracellular matrix proteinthat interacts both with other ECM proteins and with cell-surface receptors. Like many other matricellular proteins, the function of periostin is important both in embryonic development and in the remodeling of adult tissues in response to pathological insults. Periostin was originally isolated as an osteoblast-specific marker that functions as a cell adhesion molecule for preosteoblasts and is thought to be involved in osteoblast recruitment, attachment and spreading.

CDH1 (Cadherin-1) is a cell adhesion protein, member of the cadherin family. Cadherins are calcium-dependent cell adhesion proteins. They preferentially interact with themselves in a homophilic manner in connecting cells. E-cadherin (CDH1) is involved in mechanisms regulating cell-cell adhesion, mobility and proliferation of epithelial cells. CDH1 has a potent invasive suppressor role. CDH1 binds to integrin alpha-E/beta-7. Defects in CDH1 are the cause of gastric, endometrial, breast, ovary and thyroid cancers.

CD276 is a member of Costimulatory B7 molecules, signal through CD28 family molecules such as CD28, CTLA4, and ICOS. It may participate in the regulation of T-cell-mediated immune response. It can be protective role in tumor cells by inhibiting natural-killer mediated cell lysis as well as a role of marker for detection of neuroblastoma cells. Also, may be involved in the development of acute and chronic transplant rejection and in the regulation of lymphocytic activity at mucosal surfaces.