CD40 ligand (also called CD40L, CD154, or TNFSF5) is a membrane protein expressed mainly by activated CD4+ T cells, which interacts with its receptor, CD40, on a variety of cells. The crucial importance of the CD40L-CD40 system for many immune responses has been extensively described. This review focuses on the multiple roles that this system may play in HIV infection. In early HIV infection, C...

Objective This study is to determine the effects of P. gingivalis LPS and CpG on B10 cell expansion and IL-10 competency in vitro. Material and Methods Spleen B cells were isolated from C57BL/6J mice with or without formalin-fixed P. gingivalis immunization. B cells were cultured for 48 hours under the following conditions: CD40L, CD40L+LPS, CD40L+CpG, and CD40L+LPS+CpG in the presence or abs...

Sharing a Common Pathogenic Pathway? To the Editor: The paper by Urbich et al1 suggests that the CD40 pathway is involved in the vascular restenotic process. The immuneinflammatory reaction plays a critical role in atherosclerosis. In particular, the ligand for CD40 (CD40L) is involved in inflammation, thrombosis, and restenosis during progression of atherosclerosis, as discussed by Andre’ et a...

BACKGROUND CD40 ligand (CD40L) expression on platelets is mediated by agonists, but the underlying mechanism is still unclear. METHODS AND RESULTS CD40L expression was measured in platelets from healthy subjects both with and without the addition of antioxidants or a phospholipase A2 (PLA2) inhibitor and in platelets from 2 patients with an inherited deficiency of gp91phox. Immunoprecipitatio...

Hyper-IgM (HIGM) syndromes are primary immunodeficiencies characterized by defects of class switch recombination and somatic hypermutation. HIGM patients who carry mutations in the CD40-ligand (CD40L) gene expressed by CD4(+) T cells suffer from recurrent infections and often develop autoimmune disorders. To investigate the impact of CD40L-CD40 interactions on human B cell tolerance, we tested ...

CD40 ligand (CD40L) is essential for the initiation of antigen-specific T-cell responses. This study is based on the hypothesis that dendritic cells (DCs) genetically modified ex vivo to express CD40L will enhance in vivo presentation of tumor antigen to the cellular immune system with consequent induction of antitumor immunity to suppress tumor growth. To examine this concept, subcutaneous mur...

Accumulating evidence supports the early involvement of monocyte/macrophage recruitment to activated endothelial cells by leukocyte adhesion molecules during atherogenesis. CD40 and its ligand CD40L are highly expressed in vascular endothelial cells, but its impact on monocyte adhesion and the related molecular mechanisms are not fully understood. The present study was designed to evaluate the ...

Important advances have been made in the immunodiagnosis of tuberculosis (TB) based on the detection of Mycobacterium tuberculosis (MTB)-specific T cells. However, the sensitivity and specificity of the immunological approach are relatively low because there are no specific markers for antigen-specific Th cells, and some of the Th cells that do not produce cytokines can be overlooked using this...

CD40 ligand (CD40L) is an essential effector cytokine for macrophage activation, dendritic cell licensing, and T-cell-dependent antibody responses. Although CD40L is known to be made de novo following antigen recognition, several reports have described surface mobilization of preformed, intracellular CD40L in certain CD4(+) effector T cells. Here we show that rapid surface expression of preform...

OBJECTIVE To investigate the roles and signaling pathways of CD40L and CD40 in platelet-platelet interactions and thrombus formation under conditions relevant for atherothrombosis. APPROACH AND RESULTS Platelets from mice prone to atherosclerosis lacking CD40L (Cd40lg(-/-)Apoe(-/-)) showed diminished αIIbβ3 activation and α-granule secretion in response to glycoprotein VI stimulation, whereas...