The co-stimulatory receptor CD40 is a member of the tumor necrosis factor receptor (TNFR) superfamily and plays an important role in the control and regulation of immune activation, especially in crosstalk between T cells and antigen presenting cells (APCs). The natural ligand for CD40 (CD40L, CD154) is expressed on activated T cells and provides a major component of T cell “help” for the immun...

B-cell receptor (BCR)-mediated apoptosis is critical for B-cell development and homeostasis. CD40 signaling has been shown to protect immature or mature B cells from BCR-mediated apoptosis. In this study, to understand the fate of CD40-pre-activated splenic B cells stimulated by BCR engagement in the presence of CD40 signaling, murine splenic B cells were cultured with anti-Igκ and anti-CD40 an...

CD40 is a cell surface receptor important in the activation of antigen-presenting cells during immune responses. In macrophages and dendritic cells, engagement of CD40 by its ligand CD154 provides signals critical for anti-microbial and T cell-mediated immune responses, respectively. In B cells, CD40 signaling has a major role in regulating cell proliferation, antibody production, and memory B ...

BACKGROUND CD40/CD40 ligand (CD40L) signaling is a potent activator of endothelial cells (ECs) and promoter of atherosclerosis. In this study, we investigate whether A20 (a gene we have shown to be antiinflammatory and antiapoptotic in ECs) can protect from CD40/CD40L-mediated EC activation. METHODS AND RESULTS Overexpression of CD40, in a transient transfection system, activates the transcri...

CD40 is a 50-kD glycoprotein that plays an important role in B cell survival, memory, and immunoglobulin isotype switch. Engagement of the CD40 antigen by monodonal antibodies (mAbs) results in increased protein tyrosine kinase (FFK) activity, which plays an important role in mediating the biologic effects of CD40. We demonstrate, using an in situ phosphorylation technique, that CD40 cross-link...

CD40 plays a significant role in the pathogenesis of inflammation and autoimmunity. B cell CD40 directly activates cells, which can result in autoantibody production. T cells can also express CD40, with an increased frequency and amount of expression seen in CD4(+) T lymphocytes of autoimmune mice, including T cells from mice with collagen-induced arthritis. However, the mechanisms of T cell CD...

Patients with end stage renal disease (ESRD), undergoing hemodialysis, present with an alteration in immune response to anti-HBV vaccination [1]. Immunodeficiency in ESRD patients is caused by a dysregulation of various types of immune cells. The receptor CD40, which is expressed on the surface of B-cells, interacts with CD40 ligand (CD40L), which is expressed on T cells, NK cells and basophils...

The interaction between the transmembrane glycoprotein surface receptor CD40 expressed by skin epithelial cells (ECs) and its T-cell-expressed ligand CD154 was suggested to exacerbate inflammatory skin diseases. However, the full spectrum of CD40-mediated effects by ECs underlying this observation is unknown. Therefore, changes in gene expression after CD40 ligation of ECs were studied by micro...

Both type I interferon (IFN-I) and CD40 play a significant role in various infectious diseases, including malaria and autoimmune disorders. CD40 is mostly known to function in adaptive immunity, but previous observations of elevated CD40 levels early after malaria infection of mice led us to investigate its roles in innate IFN-I responses and disease control. Using a Plasmodium yoelii nigeriens...

Activated Th cells deliver contact-dependent signals to resting B lymphocytes that initiate and drive B cell proliferation. Recently, a ligand for the B lymphocyte membrane protein, CD40, has been identified that delivers contact-dependent Th cell signals to B cells. A dimeric soluble form of CD40 was produced and used to further characterize the regulation of expression of the CD40 ligand. Exp...