Stereoselective metabolism of the (+)-(S,S)- and (-)-(R,R)-enantiomers of trans-3,4-dihydroxy-3,4-dihydrobenzo[c]-phenanthrene by rat and mouse liver microsomes and by a purified and reconstituted cytochrome P-450 system

Metabolism of (+)-, (-)-, and (+/-)-trans-3,4-dihydroxy-3, 4-dihydrobenzo[c]phenanthrenes by liver microsomes from rats and mice and by a purified monooxygenase system reconstituted with cytochrome P-450c has been examined. Bay-region 3,4-diol 1,2-epoxides are minor metabolites of both enantiomers of the 3,4-dihydrodiol with liver microsomes from 3-methylcholanthrene-treated rats or with the reconstituted system (less than 10% of total metabolites). Microsomes from control and phenobarbital-treated rats and from control mice form higher percentages of these diol epoxides (13-36% of total metabolites). Microsomes from 3-methylcholanthrene-treated rats and cytochrome P-450c in the reconstituted system form exclusively the diol expoxide-1 diastereomer, in which the benzylic hydroxyl group and oxirane oxygen are cis to each other, from the (+)-(3S,4S)-dihydrodiol. The same enzymes selectively form the diol expoxide-2 diastereomer, with its oxirane oxygen and benzylic hydroxyl groups trans to each other, from the (-)-(3R,4R)-dihydrodiol (77% of the total diol epoxides). Liver microsomes from control rats show similar stereoselectivity whereas liver microsomes from phenobarbital-treated rats and from control mice are less stereoselective. Three bis-dihydrodiols and three phenolic dihydrodiols are also formed from the enantiomeric 3,4-dihydrodiols of benzo[c]phenanthrene. A single diastereomer of one of these bis-dihydrodiols with the newly introduced dihydrodiol group at the 7,8-position accounts for 79-88% of the total metabolites of the (-)-(3R,4R)-dihydrodiol formed by liver microsomes from 3-methylcholanthrene-treated rats or by the reconstituted system containing epoxide hydrolase. In contrast, the (+)-(3S,4S)-dihydrodiol is metabolized to two diastereomers of this bis-dihydrodiol, a third bis-dihydrodiol, and two phenolic dihydrodiols.     

Stereoselective formation of benzo(c)phenanthrene (+)-(3S,4R) and (+)-(5S,6R)-oxides by cytochrome P450c in a highly purified and reconstituted system

The principal oxidative metabolites formed from benzo(c)phenanthrene (B(c)Ph) by the cytochromes P450 in liver microsomes from control and treated rats are the 3,4- and 5,6-arene oxides. A procedure is described which allows determination of the enantiomer composition and absolute configuration of these arene oxides based on HPLC separation of isomeric thiolate adducts formed with N-acetyl-L-cysteine in base. Incubation of [3H]-B(c)Ph with highly purified cytochrome P450c in a reconstituted monooxygenase system followed by trapping of the metabolically formed arene oxides as above indicated that the 3,4-oxide was predominantly the (+)-(3S,4R)-enantiomer (90%) and that the 5,6-oxide consisted mainly of the (+)-(5S,6R)-enantiomer (76%). The results are discussed in terms of their implications about the catalytic binding site of cytochrome P450c.     

Biomimetic synthesis of acid-sensitive (-)- and (+)-caparrapi oxides, (-)- and (+)-8-epicaparrapi oxides, and (+)-dysifragin induced by artificial cyclases

Asymmetric total syntheses of acid-sensitive (-)- and (+)-caparrapi oxides (1) and (+)-8-epicaparrapi oxide (2) from farnesol (10) are achieved using Sharpless-Katsuki epoxidation and Lewis acid-assisted chiral Br?nsted acid (chiral LBA)-induced polyene cyclization as key steps. The relative configuration of (+)-dysifragin (4) is determined by a single-crystal X-ray diffraction and its total synthesis is accomplished by the diastereoselective epoxidation of (+)-1. Furthermore, (-)-1 can be directly synthesized from (S)-nerolidol (3) and (R)-LBA with 88% ds by reagent control, which overcame substrate control, while (-)-2 is obtained from (R)-3 and (R)-LBA with >99% ds by the double asymmetric induction.     

Synthesis of 1,2-oxygenated 6-arylfurofuran lignan: stereoselective synthesis of (1S,2S,5R,6S)-1-hydroxysamin

(1S,2S,5R,6S)-6-(3,4-Methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-1,2-diol ((+)-1-hydroxysamin 1) was synthesized, starting from olefin 8. Stereoselective alpha-hydroxylation was achieved after converting 8 to aldehyde 13. Resulting unstable alpha-hydroxy aldehyde 14 was then transformed to (+)-1-hydroxysamin (1). This is a new efficient synthetic route to 1,2-oxygenated 6-arylfurofuran lignans.     

Induction of CTL and nonpolarized Th cell responses by CD8alpha(+) and CD8alpha(-) dendritic cells

Two distinct dendritic cell (DC) subpopulations have been evidenced in mice on the basis of their differential CD8alpha expression and their localization in lymphoid organs. Several reports suggest that CD8alpha(+) and CD8alpha(-) DC subsets could be functionally different. In this study, using a panel of MHC class I- and/or class II-restricted peptides, we analyzed CD4(+) and CD8(+) T cell responses obtained after i.v. injection of freshly purified peptide-pulsed DC subsets. First, we showed that both DC subsets efficiently induce specific CTL responses and Th1 cytokine production in the absence of CD4(+) T cell priming. Second, we showed that in vivo activation of CD4(+) T cells by CD8alpha(+) or CD8alpha(-) DC, injected i.v., leads to a nonpolarized Th response with production of both Th1 and Th2 cytokines. The CD8alpha(-) subset induced a higher production of Th2 cytokines such as IL-4 and IL-10 than the CD8alpha(+) subset. However, IL-5 was produced by CD4(+) T cells activated by both DC subsets. When both CD4(+) and CD8(+) T cells were primed by DC injected i.v., a similar pattern of cytokines was observed, but, under these conditions, Th1 cytokines were mainly produced by CD8(+) T cells, while Th2 cytokines were produced by CD4(+) T cells. Thus, this study clearly shows that CD4(+) T cell responses do not influence the development of specific CD8(+) T cell cytotoxic responses induced either by CD8alpha(+) or CD8alpha(-) DC subsets.     

Monoclonal antibody (H107) inhibiting IgE binding to Fc epsilon R(+) human lymphocytes

A hybridoma-producing monoclonal antibody blocking the binding of human IgE to lymphocytes Fc receptor (Fc epsilon R) was established by the fusion of murine myeloma cells. P3X63.653.Ag8, with BALB/c spleen cells immunized with Fc epsilon R(+) human B lymphoblastoid cell line cells, RPMI1788. A clone of the hybridoma (H107) produced a monoclonal IgG2b antibody that inhibited the rosette formation of Fc epsilon R(+) human B lymphoblastoid cell line cells (RPMI1788, RPMI8866, CESS, Dakiki, and IM9) with fixed ox red blood cells (ORBC) conjugated with human IgE (IgE-ORBC). In contrast, the rosette formation with IgG-conjugated ORBC (IgG-ORBC) on Fc gamma R(+), Fc epsilon R(-) Daudi cells were not affected by the H107 antibodies. A close association of Fc epsilon R and the antigenic determinant recognized by H107 antibody was suggested by the following results. First, the bindings of 125I-labeled IgE (125I-IgE) or 125I-labeled H107 IgG2b antibody (125I-H107) to RPMI8866 cells were inhibited by cold human IgE and H107 IgG2b but not by other classes of human Ig (IgA and IgG), MPC11 IgG2b, or unrelated monoclonal antibodies. Second, H107 antibody reacted with Fc epsilon R(+) B cell lines but not with Fc epsilon R(-) B cell lines as determined by an indirect immunofluorescence. Third, Fc epsilon R(+) cells were depleted by the incubation in the dish coated with H107 antibody or IgE but not in the dish coated with unrelated antibodies. Finally, there was a correlation between the increase of Fc epsilon R(+) cells and that of H107(+) cells in the peripheral blood lymphocytes of the patients with atopic dermatitis. The surface antigens on Fc epsilon R(+) RPMI8866 cells recognized by H107 antibodies had the molecular size of 45,000 as determined by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.     

Stereoselective formation of benz[a]anthracene (+)-(5S,6R)-oxide and (+)-(8R,9S)-oxide by a highly purified and reconstituted system containing cytochrome P-450c

The principal oxidative metabolites formed from benz[a]anthracene (BA) by the rat liver microsomal monooxygenase system are the 5,6- and 8,9-arene oxides. In order to determine the enantiomeric composition and absolute configuration of these metabolically formed arene oxides, an HPLC procedure has been developed to separate the six isomeric glutathione conjugates obtained synthetically from the individual enantiomeric arene oxides. Both (+)- and (?)-BA 5,6-oxide gave the two possible positional isomers, but only one positional isomer was formed in each case from (+)- and (?)-BA 8,9-oxide. When [¹⁴C]-BA was incubated with a highly purified and reconstituted monooxygenase system containing cytochrome P-450c, and glutathione was allowed to react with the arene oxides formed, radio-active adducts were formed predominantly (>97%) from the (+)-(5S,6R) and (+)-(8R,9S) enantiomers. The present results are in accord with theoretical predictions of the steric requirements of the catalytic binding site of cytochrome P-450c.     

Susceptibility of Ad12-transformed S (+) and S (-) mouse cells to cell-mediated immunity in vitro

Adenovirus type 12 (Ad12)-transformed mouse cells were examined for their susceptibility to cell-mediated immunity in vitro, with respect to the activity of the virus-specific surface (S) antigen in the cells. A transformed cell line, C57AT1, was established from embryonic cells of C57BL/6 mice by Ad12 infection. In fluorescent antibody tests, the transformed cells were positive for the S antigen when the cells were maintained as cultures, whereas when the cells were grown as tumors in animals they became negative for the antigen (referred to as S(+) and S(-) cells, respectively). These S(+) and S(-) cells were subjected to the 51Cr-release test for cell lysis by immune spleen cells (ISC) raised in syngeneic mice by Ad12 infection. When the S(+) cells at various passage levels were exposed to ISC, all of them were lysed extensively and to a similar extent irrespective of their passage history. In contrast, the S(-) cells were consistently refractory to the action of ISC. In addition, the cytotoxic action of ISC was markedly impeded by pretreating the S(+) cells with antiserum to the S antigen, or the ISC with anti-Thy-1,2 serum plus complement. Taken these findings together, the S(+) cells were assumed to be injured by ISC through direct interaction of the S antigen with T-lymphocytes.     

Age-associated thymic atrophy is not associated with a deficiency in the CD44(+)CD25(-)CD3(-)CD4(-)CD8(-) thymocyte population.

Age-associated thymic atrophy has been proposed to be due to changes in both the thymic microenvironment and in the intrinsic properties of the early T cell progenitors, the CD44(+)CD25(-)CD3(-)CD4(-)CD8(-) cells. We have purified these cells from the thymus of both old and young mice and demonstrate no age-associated defect in their ability to differentiate into their progeny in vitro when used to reconstitute fetal thymic organ cultures. We also demonstrate that in the presence of anti-IL-7, CD44(+)CD25(-)CD3(-)CD4(-)CD8(-) cells from young mice show reduced thymocyte development in fetal thymic organ cultures compared with controls. Finally we have shown that old mice treated with IL-7 show improved thymopoiesis compared with control groups. The increased thymopoiesis seen in the old animals occurs in the sequential manner which would be anticipated for an agent working directly on the early stages, including the CD44(+)CD25(-)CD3(-)CD4(-)CD8(-) cells.     

The mechanism of a defective IFN-gamma response to bacterial toxins in an atopic dermatitis model, NC/Nga mice, and the therapeutic effect of IFN-gamma, IL-12, or IL-18 on dermatitis

NC/Nga (NC) mice raised under conventional conditions (Conv. NC mice) spontaneously develop dermatitis similar to human atopic dermatitis, whereas NC mice raised under the specific pathogen-free conditions do not develop dermatitis. In the present study, we show that the representative Th1 cytokine, IFN-gamma levels in the sera of NC mice, injected with either staphylococcal enterotoxin B or endotoxin (LPS), to be severalfold lower than those of normal mice. The low IFN-gamma response to staphylococcal enterotoxin B was correlated to the lack of regular Vbeta8(+) T cells and Vbeta8(+) NK T cells, and the low IFN-gamma response to LPS was correlated to an impaired IL-18 production of macrophages. The CD3-stimulated IL-4 production from liver and spleen T cells from Conv. NC mice in vitro was greatly augmented. The serum IL-4 levels of untreated Conv. NC mice also were higher than those of normal mice and specific pathogen-free NC mice. Treatment of Conv. NC mice either with IFN-gamma, IL-12, or IL-18 twice a week from 4 wk of age substantially inhibited the elevation of the serum IgE levels, serum IL-4 levels, and dermatitis, and IL-12 or IL-18 treatment also reduced the in vitro IL-4 production from CD3-stimulated liver T cells. The systemic deficiency in the Th1 response to bacterial stimulation thus leads to a Th2-dominant state and may induce an abnormal cellular immune response in the skin accompanied with an overproduction of IgE and a susceptibility to dermatitis in NC mice.     

Differential effects of intravenous R,S-(+/-)-3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) and its S(+)- and R(-)-enantiomers on dopamine transmission and extracellular signal regulated kinase phosphorylation (pERK) in the rat nucleus accumbens shell and core

R,S(+/-)-3,4-methylenedioxymethamphetamine (R,S(+/-)-MDMA, 'Ecstasy') is known to stimulate dopamine (DA) transmission in the nucleus accumbens (NAc). In order to investigate the post-synaptic correlates of pre-synaptic changes in DA transmission and their relationship with MDMA enantiomers, we studied the effects of R,S(+/-)-MDMA, S(+)-MDMA, and R(-)-MDMA on extracellular DA and phosphorylated extracellular signal regulated kinase (pERK) in the NAc shell and core. Male Sprague-Dawley rats, implanted with a catheter in the femoral vein and vertical concentric dialysis probes in the NAc shell and core, were administered i.v. saline, R,S(+/-)-MDMA, S(+)-MDMA, or R(-)-MDMA. Extracellular DA was monitored by in vivo microdialysis with HPLC. Intravenous R,S(+/-)-MDMA (0.64, 1, and 2 mg/kg) increased dialysate DA, preferentially in the shell, in a dose-related manner. S(+)-MDMA exerted similar effects but at lower doses than R,S(+/-)-MDMA, while R(-)-MDMA (1 and 2 mg/kg) failed to affect dialysate DA. R,S(+/-)- and S(+)-MDMA but not R(-)-MDMA increased ERK phosphorylation (expressed as density/neuron and number of pERK-positive neurons/area) in both subdivisions of the NAc. The administration of the D1 receptor antagonist, SCH 39166, prevented the increase in pERK elicited by R,S(+/-)-MDMA and S(+)-MDMA, while the D2/3 receptor antagonist, raclopride, increased pERK in the NAc core per se but failed to affect the R,S(+/-)-MDMA-elicited stimulation of pERK. The present results provide evidence that the DA stimulant effects of racemic MDMA are accounted for by the S(+)-enantiomer and that pERK may represent a post-synaptic correlate of the stimulant effect of R,S(+/-)-MDMA on D1-dependent DA transmission.     

Allergen-specific responses of CD19(+)CD5(+)Foxp3(+) regulatory B cells (Bregs) and CD4(+)Foxp3(+) regulatory T cell (Tregs) in immune tolerance of cow milk allergy of late eczematous reactions

Foxp3-expressing cells among CD19(+)CD5(+) B cells were identified as regulatory B cells. Food allergy manifesting as late eczematous reactions is regarded as a non-IgE-mediated food allergy. The diagnosis for milk allergy manifesting as late eczematous reactions was made on the basis of the findings obtained from a double-blind placebo-controlled food challenge in patients with atopic dermatitis. Twelve patients with milk allergy and 12 patients who could tolerate milk were selected. On casein stimulation, the CD19(+)CD5(+)Foxp3(+) B cell (Breg) fraction in CD5(+) B cells decreased from 4.4±1.1% to 3.1±0.7% (P=0.047, n=12) in the milk allergy group and increased from 4.4±1.3% to 5.2±1.4% (P=0.001, n=10) in the milk-tolerant group. On the other hand, on allergen stimulation, the number of CD4(+)Foxp3(+) regulatory T cells (Tregs) in the milk allergy group and milk-tolerant group increased from 2.6±0.7% to 3.4±0.6% (P=0.014, n=9) and from 2.7±1.0% to 3.5±1.0% (P=0.038, n=10), respectively. In conclusion, allergen-specific responses of Bregs, rather than those of Tregs, seem to influence the immune responses (i.e., allergy or tolerance) to a food allergen.     

(+)-(S)-trujillon, (+)-(S)-4-(2,2-diphenyl-1,3,2-oxazabolidin-5-oxo)propionic acid, a novel glutamatergic analog, modifies the activity of globus pallidus neurons by selective NMDA receptor activation

Decreased levels of glutamate and changes in several markers of glutamatergic function occur in movement disorders and chronic psychiatric illnesses. Ionotropic glutamate receptors have been implicated in neuronal cell death, and have, therefore, been related to the process of neurodegenerative diseases. Drugs that interact with the glutamatergic system are important tools for the development of better therapies. We examined the effect of a new glutamatergic analog, (+)-(S)-4-(2,2-diphenyl-1,3,2-oxazabolidin-5-oxo)propionic acid, (+)-(S)-Trujillon, on the spontaneous globus pallidus neuronal activity of the anesthetized rat. (+)-(S)-Trujillon excited most pallidal neurons in a dose-dependent manner. Furthermore, blockade of NMDA receptors (NMDARs) inhibited the (+)-(S)-Trujillon-induced excitation, whereas blockade of AMPA/kainate receptors did not. In addition, computational docking studies showed micromolar-range affinities of (+)-(S)-Trujillon for NR2A NMDARs. Our results indicate that (+)-(S)-Trujillon selectively activates NMDARs, an effect that could prove to be a useful tool in the analysis of motor, behavioral, and cognitive disorders, where NMDAR-mediated signaling is altered.     

Cloning, characterization and expression of complete coding sequences of three IgE binding Malassezia furfur allergens, Mal f 7, Mal f 8 and Mal f 9.

Malassezia furfur, formerly known as Pityrosporum orbiculare or P. ovale, is a yeast that colonizes human skin. Normally, this yeast is nonpathogenic but under the influence of predisposing factors it may induce IgE reactivity in patients with atopic dermatitis. Approximately 40-65% of atopic dermatitis patients have IgE antibodies and/or skin reactivity against M. furfur and a higher T-cell response against this yeast is found in atopic dermatitis patients than in healthy individuals. By making a cDNA library displayed on a phage surface, we previously cloned five different IgE-binding proteins, Mal f 5, Mal f 6, MF 7, MF 8 and MF 9, from this yeast. The cDNAs encoding these allergens were sequenced and expressed in Escherichia coli. The sequences of MF 7, MF 8 and MF 9 were not full length (missing their 5'-ends) giving only partial gene products. To obtain complete cDNA sequences, we performed RACE-PCR to amplify the 5'-ends of each cDNA. These PCR products were sequenced and analyzed. The coding sequences of Mal f 7, Mal f 8 and Mal f 9 encode proteins with ORFs of 141 (16.2 kDa), 179 (19.2 kDa) and 126 (14.0 kDa) amino-acid residues, respectively. None of the putative proteins showed significant sequence homology with other known proteins in the searched database. The proteins encoded by the complete cDNA sequences were expressed in E. coli as recombinant proteins. Immunoblotting and radioallergosorbant test data showed that all of the expressed recombinant proteins have the ability to bind serum IgE from atopic dermatitis patients and furthermore, the M. furfur extract could specifically inhibit this IgE binding.     

Skin homing (cutaneous lymphocyte-associated antigen-positive) CD8+ T cells respond to superantigen and contribute to eosinophilia and IgE production in atopic dermatitis.

In allergic inflammations of the skin, activation of CD4+ T cells was demonstrated to play an important role; however, a minor role for CD8+ T cells is implied. In the present study, we compared cutaneous lymphocyte-associated Ag (CLA)-expressing CD4+ and CD8+ subsets, which were isolated from peripheral blood and lesional skin biopsies in atopic dermatitis (AD) patients. We demonstrated that CD8+CLA+ T cells proliferate in response to superantigen and are as potent as CD4+CLA+ T cells in IgE induction and support of eosinophil survival. In atopic skin inflammation, the existence of high numbers of CD4+ and CD8+ T cells was demonstrated by immunohistochemistry and by culturing T cells from skin biopsies. In peripheral blood, both CD4+ and CD8+ subsets of CLA+CD45RO+ T cells were in an activated state in AD. The in vivo-activated CLA+ T cells of both subsets spontaneously released an IL-5- and IL-13-dominated Th2 type cytokine pattern. This was confirmed by intracytoplasmic cytokine staining immediately after isolation of the cells from peripheral blood. In consequence, both CD4+ and CD8+, CLA+ memory/effector T cells induced IgE production by B cells mainly by IL-13, and enhanced eosinophil survival in vitro by delaying eosinophil apoptosis, mainly by IL-5. These results indicate that in addition to the CD4+ subset, the CD8+CLA+ memory/effector T cells are capable of responding to superantigenic stimulation and play an important role in the pathogenesis of AD.     

Synthesis of (+)-(R)- and (−)-(S)-trans-8-hydroxy-2-[N-n-propyl-N-(3′-iodo-2′-propenyl)] aminotetralin: New 5-HT1A receptor ligands

(R,S)-trans-8-Hydroxy-2-[N-n-propyl-N-(3′-iodo-2′-propenyl)amino]tetralin 7 , a new radioiodinated ligand based on 8-OH-DPAT, was reported as a potential ligand for 5-HT_1A receptors. The optically active (+)-(R)- and (?)-(S)- 7 were prepared to investigate the stereoselectivity of (R,S)- 7 . Racemic intermediate 8-methoxy-2-N-n-propyltetralin was reacted with the acyl chloride of (?)-(R)-O-methylmandelic acid to form a mixture of (S,R)- and (R,R)-diastereoisomers, which were separated by flash column chromatography. After removing the N-acyl group from the diastereoisomers, the desired (+)-(R)-or (?)-(S)- 7 was obtained by adding an N-iodopropenyl group. In vitro homogenate binding studies showed the stereoselectivity of this new compound for 5-HT_1A receptors. (+)-(R)- 7 isomer displayed 100-fold higher affinity than the (?)-(S)- 7 isomer. Biochemical study indicated that (+)-(R)- 7 potently inhibited forskolin-stimulated adenylyl cyclase activity in hippocampal membranes (E_max and EC₅₀ were 24.5% and 5.4 nM, respectively), while (?)-(S)- 7 showed no effect at 1 μM. The radioiodinated (+)-(R)- and (?)-(S)-[¹²⁵I] 7 were confirmed by coelution with the resolved unlabeled compound on HPLC (reverse phase column PRP-1, acetonitrile/pH 7.0 buffer, 80/20). The active isomer, (+)-(R)-[¹²⁵I] 7 , displayed high binding affinity to 5-HT_1A receptors (K_d = 0.09 ± 0.02 nM). In contrast, the (?)-(S)- 7 isomer displayed a significantly lower affinity to the 5-HT_1A receptor (K_d > 10 nM). Thus, (+)-(R)-[¹²⁵I]trans-8-OH-PIPAT, (+)-(R)- 7 , an iodinated stereoselective 5-HT_1A receptor agonist, is potentially useful for study of in vivo and in vitro function and pharmacology of 5-HT_1A receptors in the central nervous system. © 1995 Wiley-Liss, Inc.     

Silkworm dropping extract ameliorate trimellitic anhydride-induced allergic contact dermatitis by regulating Th1/Th2 immune response

Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by hapten-specific immune response. Silkworm droppings are known to exert beneficial effects during the treatment of inflammatory diseases. Here, we studied whether topical treatment and oral administration of silkworm dropping extract (SDE) ameliorate trimellitic anhydride (TMA)-induced ACD. In ACD mice model, SDE treatment significantly suppressed the increase in both ear thickness and serum IgE levels. Furthermore, IL-1β and TNF-α levels were reduced by SDE. In allergic responses, SDE treatment significantly attenuated the production of the Th2-associated cytokine IL-4 in both ear tissue and draining lymph nodes. However, it increased the production of the Th1-mediated cytokine IL-12. Thus, these results showed that SDE attenuated TMA-induced ACD symptoms through regulation of Th1/Th2 immune response. Taken together, we suggest that SDE treatment might be a potential agent in the prevention or therapy of Th2-mediated inflammatory skin diseases such as ACD and atopic dermatitis.

Abbreviations: ACD: allergic contact dermatitis; AD: atopic dermatitis; APC: antigen presenting cells; CCL: chemokine (C-C motif) ligand; CCR: C-C chemokine receptor; Dex: dexamethasone; ELISA: enzyme-linked immunosorbent assay; IFN: interferon; Ig: immunoglobulin; IL: interleukin; OVA: ovalbumin; PS: prednisolone; SDE: silkworm dropping extract; Th: T helper; TMA: trimellitic anhydride; TNF: tumor necrosis factor     

Biomimetic conversion of (3S)-(-)-neodictyoprolenol to optically pure (1S,2R)-(-)-dictyopterene B,marine algal sex pheromone

Both enantiomers of (3S)-(-)- and (3R)-(+)-Neodictyoprolenol [(3S,5Z,8Z)-(-)-1,5,8-undecatrien-3-ol] were successfully converted to the algal sex pheromone, (1S,2R)-(-)-dictyopterene B and (1R,2S)-(+)-dictyopterene B in high enantiomeric purities (e. e. > 99%), respectively, by the biomimetic reaction involving phosphorylation and elimination under a mild condition.     

Two distinct T cell subsets, CD4+ and CD8+CD60+, and their cytokines are required for in vitro induction of human ragweed-specific memory IgE responses

CD8(+)CD60(+) T cells (80-98% CD45RO(+); 20% CD23(+)) are significantly increased in the blood of serum IgE(+) ragweed-sensitized (RS) compared with serum IgE-nonatopic humans (p = 0.001). CD8(+)CD60(+) T cells of the RS patients produced IL-2, IL-4, IL-10, IL-12, IFN-alpha. and IFN-gamma, but not IL-6 or IL-13. When their PBMC were cultured with ragweed Ag (RA), peak IgE responses occurred on day 10; none was induced with non-cross-reacting or without Ag; nonatopic PBMC did not respond to any stimulant. When either CD4(+) or CD8(+)CD60(+) T cells were depleted from RS PBMC before culture with RA, no IgE responses were induced. If purified CD4(+) T cells or low numbers of CD8(+)CD60(+) T cells were added back to the depleted PBMC, IgE responses were restored. However, higher numbers of CD8(+)CD60(+) T cells totally suppressed IgE responses. Total suppression also was obtained when RS PBMC were cultured with RA and either anti-IL-2, IL-4, IL-10, IL-12, IFN-gamma (all concentrations), or IFN-alpha (low concentrations), but not anti-IL-6 or IL-13. Higher concentrations of anti-IFN-alpha potentiated IgE responses.