We have devised an ex vivo culture system which generates large numbers of eosinophils at high purity (>90%) from unselected mouse bone marrow progenitors. In response to 4 days of culture with recombinant mouse FLT3-L and recombinant mouse stem cell factor followed by recombinant mouse IL-5 alone thereafter, the resulting bone marrow-derived eosinophils (bmEos) express immunoreactive major basic protein, Siglec F, IL-5R α-chain, and transcripts encoding mouse eosinophil peroxidase, CCR3, the IL-3/IL-5/GM-CSF receptor common β-chain, and the transcription factor GATA-1. BmEos are functionally competent: they undergo chemotaxis toward mouse eotaxin-1 and produce characteristic cytokines, including IFN-γ, IL-4, MIP-1α, and IL-6. The rodent pathogen pneumonia virus of mice replicates in bmEos and elevated levels of IL-6 are detected in supernatants of bmEos cultures in response to active infection. Finally, differentiating bmEos are readily transfected with lentiviral vectors, suggesting a means for rapid production of genetically manipulated cells.

Summary Much of the mortality attributed to influenza virus is due to secondary bacterial pneumonia, particularly from Streptococcus pneumoniae. However, mechanisms underlying this co-infection are incompletely understood. We find that prior influenza infection enhances pneumococcal colonization of the murine nasopharynx, which in-turn promotes bacterial spread to the lungs. Influenza accelerates bacterial replication in vivo, and sialic acid, a major component of airway glycoconjugates, is identified as the host-derived metabolite that stimulates pneumococcal proliferation. Influenza infection increases sialic acid and sialylated mucin availability, and enhances desialylation of host glycoconjugates. Pneumococcal genes for sialic acid catabolism are required for influenza to promote bacterial growth. Decreasing sialic acid availability in vivo by genetic deletion of the major airway mucin Muc5ac or mucolytic treatment limits influenza-induced pneumococcal replication. Our findings suggest that higher rates of disease during co-infection could stem from influenza-provided sialic acid, which increases pneumococcal proliferation, colonization and aspiration.

The regional, cellular, and subcellular distributions of N-methyl-D-aspartate (NMDA) receptor subunit 1, NMDAR-1, were investigated in monkey hippocampus by using a monoclonal antibody directed against a fusion protein corresponding to aa 660-811 of NMDAR-1. The data indicate that many neurons in each subfield of the hippocampus contain NMDAR-1 protein, although the intensity and distribution of immunoreactivity varied across regions, strata, and cellular compartments. In stratum lucidum of CA3, mossy fiber axons were immunoreactive for NMDAR-1, which may correspond to previously hypothesized presynaptic receptors. NMDAR-1-labeled postsynaptic profiles were present in stratum radiatum of CA3 but were largely absent from stratum lucidum. Such intraneuronal segregation of glutamate receptor subunits or classes may be spatially correlated with afferent systems that exhibit laminar segregation and terminate in different portions of the postsynaptic dendritic tree. For example, in CA3 pyramidal cells, NMDA receptors are postsynaptic in distal apical dendrites (stratum radiatum), where NMDA-dependent longterm potentiation in rats is mediated by associational/commissural afferents, and are absent from proximal apical dendrites (stratum lucidum), where NMDA-independent longterm potentiation is mediated by the mossy fiber input.Excitatory neurotransmission in the central nervous system is thought to be largely mediated by the excitatory amino acids glutamate and aspartate through their effects at pre-and postsynaptic receptors (1). The molecular, physiological, and structural characteristics of various excitatory amino acid receptors have been recently reviewed (2-4) and therefore will not be comprehensively described here.The function and distribution of putative postsynaptic N-methyl-D-aspartate (NMDA) receptors have been investigated in numerous physiological, pharmacological, and in situ-hybridization studies (for review, see refs. 2 and 5); however, presynaptic NMDA receptors are also proposed to exist (6). Although, several immunohistochemical studies have recently been published on the distribution of non-NMDA-receptor subunit proteins (7-12), the cellular and synaptic distribution of the NMDA subunit proteins has yet to be characterized in detail. Such data will be crucial to the development of a precise anatomical framework for the role of NMDA receptors in synaptic transmission, long-term potentiation (LTP), and the synaptic interactions between NMDA and non-NMDA-receptor classes.LTP, a potential early step in the cellular mechanism for learning (13), has been induced in various subfields of the hippocampus in rats-including region CAl via stimulation of Schaffer collaterals, region CA3 via mossy fiber and associational/commissural fiber stimulation, and in dentate gyrus granule cells after stimulation of the perforant path (14).The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §17...

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Eleven studies now report significant associations between schizophrenia and certain haplotypes of singlenucleotide polymorphisms in the gene encoding dysbindin-1 at 6p22.3. Dysbindin-1 is best known as dystrobrevin-binding protein 1 (DTNBP1) and may thus be associated with the dystrophin glycoprotein complex found at certain postsynaptic sites in the brain. Contrary to expectations, however, we found that when compared to matched, nonpsychiatric controls, 73-93% of cases in two schizophrenia populations displayed presynaptic dysbindin-1 reductions averaging 18-42% (P = 0.027-0.0001) at hippocampal formation sites lacking neuronal dystrobrevin (i.e., β-dystrobrevin). The reductions, which were not observed in the anterior cingulate of the same schizophrenia cases, occurred specifically in terminal fields of intrinsic, glutamatergic afferents of the subiculum, the hippocampus proper, and especially the inner molecular layer of the dentate gyrus (DGiml). An inversely correlated increase in vesicular glutamate transporter-1 (VGluT-1) occurred in DGiml of the same schizophrenia cases. Those changes occurred without evidence of axon terminal loss or neuroleptic effects on dysbindin-1 or VGluT-1. Our findings indicate that presynaptic dysbindin-1 reductions independent of the dystrophin glycoprotein complex are frequent in schizophrenia and are related to glutamatergic alterations in intrinsic hippocampal formation connections. Such changes may contribute to the cognitive deficits common in schizophrenia.