Stem cells in various somatic tissues (bone marrow, skeletal muscle) can be identified by the 'Side Population' marker based on Hoechst 33342 efflux. We show that mouse testicular cells also display a 'Side Population' that express Bcrp1 mRNA, the ABC transporter responsible for Hoechst efflux in hematopoietic cells. Inhibition of Hoechst efflux by specific BCRP1 inhibitor Ko143 show that germi...

To identify genes expressed by a specific subset of dendritic cells found in vivo a polymerase chain reaction-based cDNA subtraction technique was applied to the recently described germinal center dendritic cells. A novel member of the disintegrin metalloproteinase family was cloned which comprises a not typical zinc-chelating catalytic site most similar to a bacterial metalloproteinase. Dendri...

Apoptotic cells expose phosphatidylserine and are swiftly engulfed by macrophages. Milk fat globule epidermal growth factor (EGF) factor 8 (MFG-E8) is a protein that binds to apoptotic cells by recognizing phosphatidylserine and that enhances the engulfment of apoptotic cells by macrophages. We report that tingible body macrophages in the germinal centers of the spleen and lymph nodes strongly ...

About half of patients with diffuse large B-cell lymphoma (DLBCL) do not respond to or relapse soon after the standard chemotherapy, indicating a critical need to better understand the specific pathways perturbed in DLBCL for developing effective therapeutic approaches. Mice deficient in the E3 ubiquitin ligase Smurf2 spontaneously develop B-cell lymphomas that resemble human DLBCL with molecul...

The sequence of morphological changes in the rat spleen following SRBC injection associated with hemolysin production has been correlated with estimates of proliferative activity by splenic lymphatic tissue. Formation of new, reactive germinal centers containing macrophages which engulf nuclear debris is a prominent feature of the response. This is prevented by pretreatment of the animal with c...

Human immunodeficiency virus (HIV) infections have been characterized by both polyclonal B-cell activation and enhanced responsiveness to B-cell growth factors on one hand and the loss of specific antibody (Ab) responses and refractoriness to the normal signals for B-cell activation on the other. Histopathological studies of lymph node from HIV- and simian immunodeficiency virus (SIV)-infected ...