Rockefeller University

About: Rockefeller University is a education organization based out in New York, New York, United States. It is known for research contribution in the topics: Population & Gene. The organization has 15867 authors who have published 32938 publications receiving 2940261 citations. The organization is also known as: Rockefeller University & Rockefeller Institute.

The receptor tyrosine kinase Flt3 is required for dendritic cell development in peripheral lymphoid tissues

Abstract: Dendritic cell (DC) development begins in the bone marrow but is not completed until after immature progenitors reach their sites of residence in lymphoid organs. The hematopoietic growth factors regulating these processes are poorly understood. Here we examined the effects of signaling by the receptor tyrosine kinase Flt3 on macrophage DC progenitors in the bone marrow and on peripheral DCs. We found that the macrophage DC progenitor compartment was responsive to superphysiological amounts of Flt3 ligand but was not dependent on Flt3 for its homeostatic maintenance in vivo. In contrast, Flt3 was essential to the regulation of homeostatic DC development in the spleen, where it was needed to maintain normal numbers of DCs by controlling their division in the periphery.

Microglia derived from aging mice exhibit an altered inflammatory profile.

Abstract: Microglia play a critical role in neurodegenerative diseases and in the brain aging process. Yet, little is known about the functional dynamics of microglia during aging. Thus, using young and aging transgenic mice expressing enhancedgreen fluorescent protein (EGFP) under the promoter of the c-fms gene for macrophage-colony stimulating factor receptor, we evaluated in vivo-induced inflammatory responses of EGFP-expressing microglia sorted by flow cytometry. Aging microglia were characterized by the presence of lipofuscin granules, decreased processes complexity, altered granularity, and increased mRNA expression of both proinflammatory (TNFa, IL-1b, IL-6) and anti-inflammatory (IL-10, TGFb1) cytokines. Following lipopolysaccharide (LPS) challenge (1 mg/kg, 3 h), aging microglia exhibit increased basal expression of TNFa, IL-1b, IL-6, and IL-10. Yet, the foldover-basal LPS response remained constant across age, implying that the inflammatory machinery in aging microglia is functional and adjusted to the basal state. Gender differences were not overall observed across the treatments (age, LPS). The low but sustained production of pro-inflammatory cytokines by aging microglia may have a profound impact in the brain aging process. V V C 2006 Wiley-Liss, Inc.

Supersymmetry, Cosmology, and New Physics at Teraelectronvolt Energies

Abstract: If one assumes a spontaneously broken local supersymmetry, big-bang cosmology implies that the universe is filled with a gravitino (${g}_{\frac{3}{2}}$) gas---possibly its dominant constituent. From the observational bound on the cosmological mass density it follows that ${m}_{{g}_{\frac{3}{2}}}\ensuremath{\lesssim}1$ keV. Correspondingly, the supersymmetry breaking parameter $F$ satisfies $\sqrt{F}\ensuremath{\lesssim}2\ifmmode\times\else\texttimes\fi{}{10}^{3}$ TeV, requiring new supersymmetric physics in the teraelectronvolt energy region. An exact sum rule is derived and used to estimate the threshold and cross section for the production of the new states.

The distinct leukocyte integrins of mouse spleen dendritic cells as identified with new hamster monoclonal antibodies.

Abstract: Hybridoma fusions with hamster hosts were undertaken to generate mAbs to mouse spleen dendritic cells. Two mAb were obtained and used to uncover the distinct integrins of these APC. One, 2E6, bound a determinant common to all members of the CD11/CD18 family, most likely the shared 90 kD CD18 beta chain. 2E6 immunoprecipitated the characteristic beta 2 integrin heterodimers from lymphocytes (p180, 90; CD11a) and macrophages (p170,90; CD11b), but from dendritic cells, a p150,90 (presumably CD11c) integrin was the predominant species. 2E6 inhibited the binding function of the CD11a and CD11b integrins on B cells and macrophages in appropriate assays, but 2E6 exerted little or no inhibition on the clustering of dendritic cells to T cells early in primary MLR, suggesting a CD11/CD18-independent mechanism for this binding. The second mAb, N418, precipitated a 150, 90 kD heterodimer that shared the 2E6 CD18 epitope. This N418 epitope may be the murine homologue of the previously characterized human CD11c molecule, but the epitope was only detected on dendritic cells. N418 did not react with peritoneal macrophages, anti-Ig-induced spleen B blasts, or bulk lymph node cells. When used to stain sections of spleen, N418 stained dendritic cells in the T-dependent areas, much like anti-class II mAbs that were also generated in these fusions. In addition, N418 revealed nests of dendritic cells that punctuated the rim of marginal zone macrophages between red and white pulp. This localization positioned most dendritic cells at regions where arterial vessels and T cells enter the white pulp. We conclude that the p150, 90 heterodimer is the major beta 2 integrin of spleen dendritic cells, and we speculate that it may function to localize these APC at sites that permit access to the recirculating pool of resting T cells.