X-Message-Number: 33323 Date: Thu, 10 Feb 2011 20:03:48 -0800 (PST) From: Subject: B cell rejuvenation If this works in humans, then SENS just became a little easier to achieve. Blood. 2011 Jan 12. [Epub ahead of print] B cell depletion reactivates B lymphopoiesis in the BM and rejuvenates the B lineage in aging. Keren Z, Naor S, Nussbaum S, Golan K, Itkin T, Sasaki Y, Schmidt-Supprian M, Lapidot T, Melamed D. Department of Immunology, Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Abstract Aging is associated with a decline in B-lymphopoiesis in the bone marrow and accumulation of long-lived B-cells in the periphery. These changes decrease the body's ability to mount protective antibody responses. We show here that age-related changes in the B lineage are mediated by the accumulating long-lived B cells. Thus, depletion of B-cells in old mice was followed by expansion of multipotent primitive progenitors (MPPs) and common lymphoid progenitors (CLPs), a revival of B-lymphopoiesis in the bone marrow, and generation of a rejuvenated peripheral compartment that enhanced the animal's immune responsiveness to antigenic stimulation. Collectively, our results suggest that immunosenescence in the B-lineage is not irreversible, and that depletion of the long-lived B cells in old mice rejuvenates the B-lineage and enhances immune competence. PMID: 21228330 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=33323