CD45 is a family of transmembrane protein tyrosine phosphatases exclusively expressed by hematopoietic cells and critically involved in the regulation of T cell activation signals, We now demonstrate that three 100-mu g doses of antiCD45RB mAb MB23G2 can induce long-term engraftment of islets into major histcompatibility complex-disparate chemically diabetic mice, Long-term graft survivors (>120 days) were tolerant to new islet allografts from the original donor strain, MB23G2 induced a temporary decrease in number circulating leukocytes but had no effect on leukocyte number in other lymphoid compartments, Histologic examination...

Background: The nodular sclerosis and mixed cellularity subtypes of Hodgkin’s disease are histologically characterised by a small population of neoplastic cells, the so-called Reed-Sternberg cells and their mononuclear variants (RS cells) and an extensive admixture of other cell types including lymphocytes, plasma cells, eosinophils, and histiocytes. The nature of this infiltrate is largely known, but the mechanisms and functional effects are not. The small lymphocytes immediately surrounding the RS cells are mostly CD4+ T cells that express early activation markers. The absence of prominent specific cytotoxic I cell...

CD45 is the dominant tyrosine phosphatase in haematopoietic cells and can modulate the effects of many other signaling molecules by dephosphorylation. The extracellular portion of CD45 has considerable variability due to differential splicing and glycosylation. This may allow for interactions with a variety of ligands expressed on interacting cells or on the same cell surface. Monoclonal anti CD45 antibodies that are reactive with epitopes that result from differential splicing and glycosylation can distinguish between cell populations that differ in maturation and function. These reagents can be used in...