Epidermal keratinocytes (EK) are exposed to multiple inflammatory stimuli and paracrine factors secreted by various dermal cells (lymphocytes, mast cells, macrophages, fibroblasts) during wounding, cutaneous allergy, and infections. We have previously demonstrated that after stimulation with interleukin 4 or interferon-y, human EK express the low-affinity receptor for IgE (FceRII/CD23) on their...

The markers, CD11b, CD11c, CD14, CD21, CD23, CD25, CD38, and FMC7 were correlated with morphologic and other laboratory and clinical characteristics of 127 patients with untreated CD5+ chronic lymphocytic leukemia (CLL). Only CD38 and CD21 were significantly associated with atypical CLL morphology. The integrin associated markers CD11b and CD11c were associated with lower leukocyte count (white...

Irradiation instructs mast cells to rebuild blood vessels in oxygen-deprived tissues, according to Heissig and colleagues on page 739. Low-dose irradiation mobilized adult and precursor mast cells, which traveled to the ischemic tissue and produced the vessel-building growth factor VEGF (vascular endothelial growth factor). Ionizing irradiation has been shown to promote the growth of new blood ...

Interleukin-7 (IL-7) is a B-cell growth factor produced by both bone marrow stroma cells and follicular dendritic cells (FDCs) located in primary lymphoid follicles and germinal centers. In this study, we have evaluated the role of IL-7 on human Ig class switching. IL-7 was added to peripheral blood mononuclear cells (PBMCs) or tonsillar B cells in the absence or presence of IL-4 and/or anti-CD...

The proteolytic activity of a disintegrin and metalloproteinase 10 (ADAM10) regulates cell-fate decisions in Drosophila and mouse embryos. However, in utero lethality of ADAM10(-/-) mice has prevented examination of ADAM10 cleavage events in lymphocytes. To investigate their role in B cell development, we generated B cell-specific ADAM10 knockout mice. Intriguingly, deletion of ADAM10 prevented...

Type 1 immunity appears to be diminished in healthy Japanese carriers of human T-lymphotropic virus type I (HTLV-I), but type 2 status remains undetermined. To further examine the subclinical effect of HTLV-I on host immunity, we measured serum antibodies to the Epstein-Barr virus (EBV) in 415 healthy Japanese adults to broadly characterize type 1 status. Levels of the type 2 biomarkers total i...

Our previous investigation of a patient (pt1) with non-X-linked hyper-immunoglobulin M syndrome revealed a CD40-mediated defect in B cell activation that resulted in low CD23 expression and absence of germ-line transcription and class-switch recombination. These deficiencies were complemented in vitro by a high threshold of sustained signaling through CD40. To further analyze the signaling defe...

CD23, also known as the low affinity IgE receptor (FcepsilonRII), has been hypothesized to have a role in IgE regulation. A new CD23 transgenic mouse was generated using the MHC class I promoter and IgH enhancer to further test the hypothesis that CD23 plays a role in the down-regulation of IgE. Study of three founder lines by FACS showed overexpression to varying extents on both B and T lympho...