IL-33, a member of the IL-1-related cytokines, is considered to be a proallergic cytokine that is especially involved in Th2-type immune responses. Moreover, like IL-1α, IL-33 has been suggested to act as an "alarmin" that amplifies immune responses during tissue injury. In contrast to IL-1, however, the precise roles of IL-33 in those settings are poorly understood. Using IL-1-and IL-33-deficient mice, we found that IL-1, but not IL-33, played a substantial role in induction of T cellmediated type IV hypersensitivity such as contact and delayed-type hypersensitivity and autoimmune diseases such as experimental autoimmune encephalomyelitis. Most notably, however, IL-33 was important for innate-type mucosal immunity in the lungs and gut. That is, IL-33 was essential for manifestation of T cell-independent protease allergen-induced airway inflammation as well as OVA-induced allergic topical airway inflammation, without affecting acquisition of antigenspecific memory T cells. IL-33 was significantly involved in the development of dextran-induced colitis accompanied by T cell-independent epithelial cell damage, but not in streptozocin-induced diabetes or Con A-induced hepatitis characterized by T cell-mediated apoptotic tissue destruction. In addition, IL-33-deficient mice showed a substantially diminished LPS-induced systemic inflammatory response. These observations indicate that IL-33 is a crucial amplifier of mucosal and systemic innate, rather than acquired, immune responses.asthma | colitis | cytokine | interleukin-33 | sepsis

cDNA encoding a novel phosphodiesterase (PDE) was isolated from a human fetal lung cDNA library and designated PDE10A. The deduced amino acid sequence contains 779 amino acids, including a putative cGMP binding sequence in the amino-terminal portion of the molecule and a catalytic domain that is 16 -47% identical in amino acid sequence to those of other PDE families. Recombinant PDE10A transfected and expressed in COS-7 cells hydrolyzed cAMP and cGMP with K m values of 0.26 and 7.2 M, respectively, and V max with cGMP was almost twice that with cAMP. Of the PDE inhibitors tested, dipyridamole was most effective, with IC 50 values of 1.2 and 0.45 M for inhibition of cAMP and cGMP hydrolysis, respectively. cGMP inhibited hydrolysis of cAMP, and cAMP inhibited cGMP hydrolysis with IC 50 values of 14 and 0.39 M, respectively. Thus, PDE10A exhibited properties of a cAMP PDE and a cAMP-inhibited cGMP PDE. PDE10A transcripts were particularly abundant in the putamen and caudate nucleus regions of brain and in thyroid and testis, and in much lower amounts in other tissues. The PDE10A gene was located on chromosome 6q26 by fluorescent in situ hybridization analysis. PDE10A represents a new member of the PDE superfamily, exhibiting unique kinetic properties and inhibitor sensitivity.Cyclic nucleotides cAMP and cGMP are well known as second messengers and regulate many functions in various tissues (1-4). Intracellular cAMP and cGMP concentrations are controlled via stimulation of adenyl and guanyl cyclases in response to extracellular signaling and their degradation by cyclic nucleotide phosphodiesterases (PDEs), 1 respectively. Many kinds of PDEs are involved in the metabolism of cyclic nucleotides. Based on their amino acid sequence homology, biochemical properties, and inhibitor profiles, seven PDE families have been recognized in mammalian tissues (5, 6). PDE1 is Ca 2ϩ / calmodulin-dependent, hydrolyzing both cAMP and cGMP. PDE2 is stimulated by cGMP and hydrolyzes cAMP and cGMP.PDE3 is cGMP-inhibited. PDE4 is cAMP-specific and rolipramsensitive. PDE5 is cGMP-specific. PDE6 is a photoreceptor cGMP PDE. PDE7 is cAMP-specific and rolipram-insensitive. Very recently, cDNAs encoding two kinds of novel PDEs were isolated from humans and mice (7-11). One is cAMP-specific (PDE8), and the other is cGMP-specific (PDE9). PDE7 and the two latter PDEs are insensitive to the nonspecific PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX). cDNA cloning of these novel PDEs was done by an approach using bioinformatics. A search of data bases of expressed sequence tags (ESTs) was performed using parts of PDE sequences such as the catalytic domain. The approach was shown to be effective for the isolation of novel PDE cDNAs.Genome sequencing projects are progressing in many organisms, providing us information of a variety of pathways involved in the cyclic nucleotide metabolism necessary to maintain life. In Caenorhabditis elegans, which is a small soil nematode found in temperate regions, there are five pairs of autosomal chromosomes and a...

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Fluorescence in situ hybridization has been used to visualize specific genomic DNA sequences in interphase nuclei. In normal diploid cells, unreplicated DNA segments give singlet hybridization signals while replicated loci are characterized by doublets. The distribution of these two patterns in unsynchronized cell populations can be used to determine the S phase replication time of any DNA sequence. The validity of this approach was established by analyzing genes whose replication profiles in expressing and non‐expressing cells had been determined previously by conventional methods. Using this technique it has been possible to map the replication timing topography of the DNA within and flanking the cystic fibrosis (CF) gene locus on chromosome 7. The gene itself is located within a defined time zone which is approximately 500 kb in length and is under developmental control. It is early replicating in cells which express CF but late replicating in other cell types. These time zones probably represent basic units of chromosome structure.

Cytotoxic treatment with rabbit antiserum raised against purified glycosphingolipid "asialo GM1" was capable of eliminating natural killer (NK) activity of spleen cells from different inbred mouse strains including CBA/J, C57BL/6, BALB/c, AKR, and athymic nude mice. The anti-asialo GM1 antiserum showed little cross-reactivity with structurally related glycolipids, e.g. GM), GD 1 b and asialo GM2 in the microflocculation test. The specific reactivity of this antiserum with NK cells was confirmed by the quantitative absorption of anti-NK activity with graded amounts of asialo GM1 but not with other glycosphingolipids. The absorption of anti-brain-associated T cell antigen (anti-BAT) with asialo GM1 also effectively diminished its anti-NK activity, leaving the ability to kill T cells intact. This suggests that the antibody to asialo GM1 is responsible for the anti-NK activity contained in the anti-BAT antiserum. In contrast to the extreme sensitivity of NK cells to anti-asialo GM1, alloreactive cytotoxic T killer cells generated in the mixed lymphocyte culture were not killed by anti-asialo GM1 and complement. These results indicate that asialo GM1 is expressed on mouse NK cells in a high concentration.