The initial contact between axons and dendrites at early neuronal synapses is mediated by surface adhesion molecules and is thought to induce synaptic maturation through the recruitment of additional synaptic proteins. The initiation of synaptic maturation should be tightly regulated to ensure that synaptic maturation occurs selectively at subcellular sites of axo-dendritic adhesion. However, t...

Although retinoic acid receptor alpha (RARalpha) agonists induce the maturation of t(15;17) acute promyelocytic leukemia (APL) cells, drug treatment also selects leukemic blasts expressing PML-RARalpha fusion proteins with mutated ligand-binding domains that no longer respond to all-trans retinoic acid (ATRA). Here we report a novel RARalpha-independent signaling pathway that induces maturation...

We analyzed the interaction between human peripheral blood natural killer (NK) cells and monocyte-derived immature dendritic cells (DC). Fresh NK cells were activated, as indicated by the induced expression of the CD69 antigen, and their cytolytic activity was strongly augmented by contact with lipopolysaccharide (LPS)-treated mature DC, or with immature DC in the presence of the maturation sti...

Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasma. Physiologically, free radicals control sperm maturation, capacitation and hyperactivation, the acrosome reaction, and sperm-oocyte fusion. Pathologically, free radicals induce lipid peroxidation, DNA damage and apoptosis of spermatozoa. The present review deals with both the beneficial and detrim...

Growth of C-1300 neuroblastoma was markedly suppressed in mice chemically sympathectomized at birth with 6-hydroxydopamine. Growth of A-10 adenocarcinoma was also somewhat reduced. In newborn mice pretreated with nerve growth factor to induce sympathetic nervous system neuronal hypertrophy, neuronal maturation, and peripheral hyperinnervation, the growth of neuroblastoma was augmented.

The number of melanocytes positive to the dopa reaction in the epidermis was shown to increase after newborn mice were injected with alpha-MSH or DBc-AMP. The agents seemed to induce the initiation of melanogenesis in the pre-existing melanoblasts. Electron-microscopic observation also demonstrated that alpha-MSH induced not only maturation of melanosomes but also the formation of melanosomes.

Invasive bacteria actively induce their own uptake by phagocytosis in normally nonphagocytic cells and then either establish a protected niche within which they survive and replicate, or disseminate from cell to cell by means of an actin-based motility process. The mechanisms underlying bacterial entry, phagosome maturation, and dissemination reveal common strategies as well as unique tactics e...

Dendritic cells are cells specialized for antigen capture, migration and T cell stimulation. Recent advances have been made in understanding their origin, their heterogeneity, the mechanism of antigen uptake, and the signals that induce their migration and maturation into immunostimulatory antigen-presenting cells. Dendritic cells represent the natural adjuvants for T cell responses and their t...