Hepatitis B core antigen-specific IFN-gamma production of peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

To evaluate the specificity of cellular immune response to hepatitis B virus (HBV) Ag in patients with chronic HBV infection, we have measured IFN-gamma production and proliferation of PBMC of 16 patients with chronic active hepatitis (CAH), 17 asymptomatic carriers of HBV (ASC), 6 anti-hepatitis B surface (HBs)-positive subjects, and 6 control individuals with ELISA procedure and [3H]thymidine incorporation. There was no significant increase in the mean proliferative response to recombinant HB surface and core Ag (rHBsAg and rHBcAg), nor was IFN-gamma production elicited with rHBsAg in any group. In contrast, PBMC of HBeAg-positive and anti-HBe-positive CAH patients, and anti-hepatitis B "e" Ag (HBe)-positive ASC showed significantly enhanced IFN-gamma production in response to HBcAg, whereas those of HBeAg-positive ASC and anti-HBs-positive subjects did not respond to HBcAg. The maximal response was observed in a 5-day culture with 500 ng/ml of rHBcAg when assessed by stimulation index value. Monocytes did not demonstrate an increased suppressor or helper activity for IFN-gamma production in these patients. T cell subset fractionation revealed that CD4+ cells were main population of IFN-gamma production specific for HBcAg and CD8+ cells did not suppress IFN-gamma production of CD4+ cells. Furthermore, CD4+ cells of HBeAg-positive ASC generated lesser amounts of IFN-gamma than HBeAg-positive CAH patients did. These results show that the measurement of IFN-gamma production is useful to determine cellular immune response to HBV Ag and suggest that IFN-gamma production depends on the helper activity of CD4+ T cells sensitized to HBcAg.     

Effects of a New Calcium Channel Blocker, KB-2796, on Protein Synthesis of the CA1 Pyramidal Cell and Delayed Neuronal Death Following Transient Forebrain Ischemia

The effects of a new calcium channel blocker, 1-[bis(4-fluorophenyl)methyl]-4-(2,3,4-trimethoxybenzyl)-piperazine dihydrochloride (KB-2796), on delayed neuronal death (DND) in the hippocampus were examined in gerbils in comparison with those of pentobarbital and flunarizine. The neuronal density in the hippocampal CA1 subfield was counted on the seventh day of recirculation following 5 min of bilateral carotid occlusion, and protein biosynthesis in the brain was also determined at 1, 2, 4, 24, and 72 h following occlusion. The drugs were intraperitoneally administered after recirculation. KB-2796 (10 mg/kg) significantly prevented DND in the CA1 subfield. Pentobarbital (40 mg/kg), but not flunarizine (3 and 10 mg/kg), inhibited DND. Protein synthetic activity in the CA1 subfield was reduced by ischemia and the reduction was not restored even at 72 h after recirculation. KB-2796 did not ameliorate the reduction of protein synthesis in the CA1 subfield by 24 h after recirculation, but in one of three animals restoration of protein synthesis was observed at 72 h of recirculation. Pentobarbital also restored the reduced protein synthesis in two of three animals at 72 h. These results suggest that calcium influx into neurons participates in the pathogenesis of DND, and also that KB-2796 might prevent both morphological and functional cell damage in CA1 neurons induced by transient ischemia.     

Photoaffinity labeling with dihydropyridine derivatives of crude membranes from rat skeletal, cardiac, ileal, and uterine muscles and whole brain

The characteristics of photoaffinity labeling with the calcium agonist [3H]Bay K 8644 (Bay) and the calcium antagonists [3H]nitrendipine (Nit) and (+)PN200-110 (PN) of crude membranes from rat skeletal, cardiac, ileal, and uterine muscles and whole brain were investigated. In all these crude membranes, [3H](+)PN (20 nM) was mainly photoincorporated into one protein band with a molecular weight of 30,000 - 41,000 Da. It was also incorporated into some other bands of all these crude membranes. The photoincorporation of [3H](+)PN into these crude membranes was inhibited by the presence of 20 microM unlabeled (+)PN. The photoincorporation of [3H](+)PN into these crude membranes depended on its dose and on the time of UV irradiation. No incorporation of [3H](+)PN was observed in the absence of UV irradiation. The incorporation was not affected by the presence of 1 mM CaCl2 and/or 0.15 M NaCl, but was significantly decreased by 20 microM (+)PN and slightly decreased by 20 microM (-)PN, 20 microM Bay, 1 mM diltiazem, or 1 mM verapamil. Namely, enantiomers of PN caused various extents of stereoselective inhibition of photoaffinity labeling by [3H](+)PN of specific protein bands in these crude membranes. [3H]Nit was photoincorporated into these crude membranes in the same way as [3H](+)PN, but [3H]Bay was not photoincorporated. However, 20 microM unlabeled Nit did not consistently inhibit photoaffinity labeling with [3H]Nit. These findings suggested that measurement of photoaffinity of crude membranes from rat skeletal, cardiac, and uterine muscles and whole brain with [3H](+)PN by UV irradiation is a useful method for investigating the characteristics of the voltage-dependent calcium channels that are affected by 1,4-dihydropyridine derivatives.     

Cetacean relaxin. Isolation and sequence of relaxins from Balaenoptera acutorostrata and Balaenoptera edeni

The tendency toward extremely high variability among relaxins derived from purportedly closely related species has come to an abrupt end with the discovery of quasi-porcine relaxin in the minke whale (Balaenoptera acutorostrata) and the Bryde's whale (Balaenoptera edeni). An aqueous abstract of the corpora lutea of the two baleen whales contained significant amounts of relaxin-like activity as determined by a mouse bioassay and by cross-reactivity with anti-pig relaxin antibodies. The activity could be isolated and purified to homogeneity. Sequence analysis revealed that both whale relaxins differed from each other by about 3 residues, whereas the relaxin of B. edeni differed at only one position from that of pig relaxin. The similarity appears to include even the chain length heterogeneity observed at the C-terminal end of the B chain in porcine relaxin which is produced by a peculiar mode of connecting peptide removal from the pro-hormone. This finding may well represent one of the better documented challenges to the current paradigm of molecular evolution.     

Partial purification and characterization of membrane-associated diacylglycerol kinase of Drosophila heads.

A membrane-associated diacylglycerol kinase of Drosophila heads was purified to near homogeneity from the KCl extract of Drosophila heads. The purification procedure involved chromatography on Q-Sepharose, ammonium sulfate fractionation, Superose 12, hydroxyapatite and ATP-agarose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of fractions after the ATP-agarose column chromatography showed that only a 115 kDa protein correlated well with the enzyme activity. The apparent Km values of partially purified DG kinase were 220 microM for ATP and 540 microM for diolein, respectively. The activity of the DG kinase was inhibited by deoxycholate and was not activated by Ca2+.     

A Drosophila receptor-type tyrosine kinase (DFR1) acts as a fibroblast growth factor receptor in Xenopus embryos

Members of the fibroblast growth factor (FGF) family play important roles in various developmental processes in vertebrates. Since two genes closely related to the vertebrate FGF receptor (FGFR) genes DFR1 and DFR2/breathless have already been reported in Drosophila , the existence of a Drosophila FGF has been predicted. In the present study, we examined whether DFR1 is functionally interchangeable with a vertebrate FGFR in the Xenopus system. First, we found that the expression of DFR1 promoted Ca²⁺ efflux in response to human basic (b)FGF in Xenopus oocytes, whereas the coexpression of a dominant negative form of DFR1 (ΔDFR1) with a chick FGFR1/cek1 inhibited promotion of Ca²⁺ efflux induced by the expression of cek1 in the oocyte. Second, the expression of ΔDFR1 was observed to induce a defect in the posterior structure of the Xenopus embryo at stage 30, as observed with a dominant negative form of cek1 (Δcek1). Third, we found that the expression of ΔDFR1 inhibited the expression of FGF-regulated genes such as Xbra, Xnot , and Xshh in Xenopus embryos at stage 11, while the coexpression of DFR1 with ΔDFR1 could rescue the inhibited expression of FGF-regulated genes. These results indicate that DFR1 acts as an FGFR in Xenopus embryos and that an FGF is likely to exist in Drosophila .     

Specific antitumor activity of tumor-infiltrating lymphocytes expanded first in a culture with both anti-CD3 monoclonal antibody and activated B cells and then in a culture with interleukin-2

In order to expand tumor-infiltrating lymphocytes (TIL) efficiently and in order to use them for immunotherapy, we utilized lipopolysaccharide-activated B cells (LPS blasts) as costimulatory-signal-providing cells in an in vitro culture system. TIL, prepared from subcutaneously inoculated B16 melanoma, failed to expand when cultured with anti-CD3 monoclonal antibody (mAb) alone followed by a low dose of interleukin(IL)-2. In contrast, such TIL did expand efficiently in culture with both anti-CD3 mAb and LPS blasts followed by culture with IL-2. These findings suggest that the presence of LPS blasts in the initial culture was essential for the cell expansion. The expansion of TIL was partially blocked by the addition of CTLA4 Ig, which is an inhibitor of costimulatory molecules such as CD80 and CD86, and was almost blocked by the addition of anti-(Fc receptor II)mAb. These findings thus indicate that such molecules, in conjunction with the receptor on the LPS blasts, participate in the efficient expansion of TIL. The B16-derived TIL, which expanded in our culture system, were predominantly CD8+T cells and showed a higher level of cytolytic activity against B16 melanoma than either lymphokine-activated killer cells or TIL cultured with a high dose of IL-2. In addition, the in vitro expanded B16-derived TIL produced interferon , but not IL-4, in response to B16 melanoma. What is more important, the adoptive transfer of such TIL had a significant antitumor effect against pulmonary metastasis in B16 melanoma, even without the concurrent administration of IL-2. Collectively, our results thus indicate the therapeutic efficacy of the protocol presented here for antitumor immunotherapy with TIL.This work was supported in part by a grant from the Ministry of Education, Science and Culture     

Expression of Dictyostelium early gene, dutA, is independent of cAMP pulses but dependent on protein kinase A

Abstract The untranslatable, RNA polymerase II-dependent gene ( dutA ) of Dictyostelium discoideum is induced early in development. However, unlike other early genes, dutA induction was not affected by cAMP pulses and occurred normally in various cAMP-related mutant cells, the results indicating that this induction depended solely on factors other than cAMP. In the knockout strain of the catalytic subunit of protein kinase A, dutA expression was severely blocked and not recovered by cAMP pulses. This demonstrates that even the cAMP-independent gene, dutA , requires protein kinase A for its expression.