Role of CD7 expressed in lung microvascular endothelial cells as Fc receptor for immunoglobulin M

Motoko Nishimura1, Minoko Takanashi, Hitoshi Okazaki

  • 1Research Section, Tokyo Metropolitan Red Cross Blood Center, Tokyo, Japan. mo-nishimura@tokyo.bc.jrc.or.jp

Immunoglobulins (Igs) against anti-human white blood cells are putative contributors to the development of transfusion-related adverse effects, particularly transfusion-related acute lung injury (TRALI). Studies of Igs that are considered to be implicated in transfusion-related adverse effects have mainly focused on immunoglobulin G (IgG) class antibodies (Abs). In the authors' previous in vitro study, the association of polymorphonuclear neutrophils (PMNs) and lung microvascular endothelial (LME) cells was up-regulated in the presence of normal human serum-derived IgMs, when F(ab')2 fragments of IgMs were specific to low-affinity Fc receptors (FcR) for IgG, namely, Fcgamma R III (CD16) and Fcgamma RII (CD32). In this study, the authors found that CD7 antigen notably expresses in LME cells and that it acts as an Fc receptor for IgM in LME cells.

Related Concept Videos

Immunoglobulin-like Cell Adhesion Molecules01:31

Immunoglobulin-like Cell Adhesion Molecules

Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...