Generation and Immunity Testing of a Recombinant Adenovirus Expressing NcSRS2-NcGRA7 Fusion Protein of Bovine Neospora caninum

Neospora caninum is the etiologic agent of bovine neosporosis, which affects the reproductive performance of cattle worldwide. The transmembrane protein, NcSRS2, and dense-granule protein, NcGRA7, were identified as protective antigens based on their ability to induce significant protective immune responses in murine neosporosis models. In the current study, NcSRS2 and NcGRA7 genes were spliced by overlap-extension PCR in a recombinant adenovirus termed Ad5-NcSRS2-NcGRA 7, expressing the NcSRS2-NcGRA7 gene, and the efficacy was evaluated in mice. The results showed that the titer of the recombinant adenovirus was 10(9)TCID50/ml. Three weeks post-boost immunization (w.p.b.i.), the IgG antibody titer in sera was as high as 1:4,096. IFN-gamma and IL-4 levels were significantly different from the control group (P<0.01). This research established a solid foundation for the development of a recombinant adenovirus vaccine against bovine N. caninum.

7-Alkyl-N(2)-substituted-3-deazaguanines. Synthesis, DNA polymerase III inhibition and antibacterial activity.

Several 2-anilino- and 2-benzylamino-3-deaza-6-oxopurines [3-deazaguanines] and selected 8-methyl and 8-aza analogs have been synthesized. 7-Substituted N(2)-(3-ethyl-4-methylphenyl)-3-deazaguanines were potent and selective inhibitors of Gram+ bacterial DNA polymerase (pol) IIIC, and 7-substituted N(2)-(3,4-dichlorobenzyl)-3-deazaguanines were potent inhibitors of both pol IIIC and pol IIIE from Gram+ bacteria, but weakly inhibited pol IIIE from Gram- bacteria. Potent enzyme inhibitors in both classes inhibited the growth of Gram+ bacteria (MICs 2.5-10µg/ml), and were inactive against the Gram- organism Escherichia coli. Several derivatives had moderate protective activity in Staphylococcus aureus-infected mice.

Hybrid antibacterials. DNA polymerase-topoisomerase inhibitors.

Novel Gram-positive (Gram+) antibacterial compounds consisting of a DNA polymerase IIIC (pol IIIC) inhibitor covalently connected to a topoisomerase/gyrase inhibitor are described. Specifically, 3-substituted 6-(3-ethyl-4-methylanilino)uracils (EMAUs) in which the 3-substituent is a fluoroquinolone moiety (FQ) connected by various linkers were synthesized. The resulting "AU-FQ" hybrid compounds were significantly more potent than the parent EMAU compounds as inhibitors of pol IIIC and were up to 64-fold more potent as antibacterials in vitro against Gram+ bacteria. The hybrids inhibited the FQ targets, topoisomerase IV and gyrase, with potencies similar to norfloxacin but 10-fold lower than newer agents, for example, ciprofloxacin and sparfloxacin. Representative hybrids protected mice from lethal Staphylococcus aureus infection after intravenous dosing, and one compound showed protective effect against several antibiotic-sensitive and -resistant Gram+ infections in mice. The AU-FQ hybrids are a promising new family of antibacterials for treatment of antibiotic-resistant Gram+ infections.

Synthesis and antibacterial activity of 3-substituted-6-(3-ethyl-4-methylanilino)uracils.

Numerous 3-substituted-6-(3-ethyl-4-methylanilino)uracils (EMAU) have been synthesized and screened for their capacity to inhibit the replication-specific bacterial DNA polymerase IIIC (pol IIIC) and the growth of Gram+ bacteria in culture. Direct alkylation of 2-methoxy-6-amino-4-pyrimidone produced the N3-substituted derivatives, which were separated from the byproduct 4-alkoxy analogues. The N3-substituted derivatives were heated with a mixture of 3-ethyl-4-methylaniline and its hydrochloride to effect displacement of the 6-amino group and simultaneous demethylation of the 2-methoxy group to yield target compounds in good yields. Certain intermediates, e.g. the 3-(iodoalkyl) compounds, were converted to a variety of (3-substituted-alkyl)-EMAUs by displacement. Most compounds were potent competitive inhibitors of pol IIIC (K(i)s 0.02-0.5 microM), and those with neutral, moderately polar 3-substituents had potent antibacterial activity against Gram+ organisms in culture (MICs 0.125-10 microg/mL). Several compounds protected mice from lethal intraperitoneal (ip) infections with S. aureus (Smith) when given by the ip route. A water soluble derivative, 3-(4-morpholinylbutyl)-EMAU hydrochloride, given subcutaneously, prolonged the life of infected mice in a dose dependent manner.

Active site directed inhibitors of replication-specific bacterial DNA polymerases.

7-Substituted-N(2)-(3,4-dichlorobenzyl)guanines potently and competitively inhibit DNA polymerases IIIC and IIIE from Gram(+) bacteria. Certain derivatives are also competitive inhibitors of DNA polymerase IIIE from Gram(-) bacteria.

Synthesis of substituted 6-anilinouracils and their inhibition of DNA polymerase IIIC and Gram-positive bacterial growth.

Certain substituted 6-anilinouracils are potent and selective inhibitors of Gram+ bacterial DNA polymerase IIIC (pol IIIC). In addition, analogues with 3-substituents in the uracil ring have potent antibacterial activity against Gram+ organisms in culture. In an attempt to find optimal anilino substituents for pol IIIC binding and optimal 3-substituents for antibacterial activity, we have prepared several series of 3-substituted-6-aminouracils and assayed their activity against pol IIIC from Bacillus subtilis and a panel of Gram+ and Gram- bacteria in culture. The 6-(3-ethyl-4-methylanilino) group and closely related substituent patterns maximized pol IIIC inhibition potency. Among a series of 3-(substituted-butyl)-6-(3-ethyl-4-methylanilino)uracils, basic amino substituents increased pol IIIC inhibition, but decreased antibacterial activity. The most potent antibacterials were simple hydroxybutyl and methoxybutyl derivatives, and hydrophobically substituted piperidinylbutyl derivatives.

The Activation of Carbon-Chlorine Bonds in Per- and Polyfluoroalkyl Chlorides: DMSO-Induced Hydroperfluoroalkylation of Alkenes and Alkynes with Sodium Dithionite.

In DMSO, the addition reactions of perfluoroalkyl chlorides, R(F)Cl, to alkenes or alkynes can occur smoothly in the presence of 1.5 equiv of Na(2)S(2)O(4) and NaHCO(3) at 75-80 degrees C for 4-10 h to give the corresponding adducts (RCH(2)CH(2)R(F) or RCH=CHR(F)). Ethyl chlorofluoro- (1f), chlorodifluoro- (1g) acetates, even nonfluorinated compounds, such as ethyl dichloro- (1h), chloro- (1i) acetates, and chloroform (1j) can undergo the similar reaction. Treatment of omega-iodo (or chloro-) perfluoroalkyl chlorides [X(CF(2))(n)()Cl, n = 2, 4, X= I or Cl] with >3 equiv of alkenes and Na(2)S(2)O(4) gives directly the symmetrically disubstituted alkanes (RCH(2)CH(2))(2)(CF(2))(n)(). The symmetrically and unsymmetrically disubstituted adducts RCH(2)CH(2)(CF(2))(n)()CH(2)CH(2)R' from omega- iodoperfluoroalkyl chlorides can be also obtained stepwise, i.e., through the further addition reactions of monoadducts, RCH(2)CH(2)(CF(2))(n)()Cl to olefins. However, for alpha,omega-dichloroperfluoroalkanes, the similarly stepwise reactions with an alkene is not clean, both bis-adducts and the corresponding omega-hydrides, RCH(2)CH(2)(CF(2))(n)()H as byproducts are also formed. In the absence of alkenes or alkynes, per- and polyfluoroalkyl chlorides can be converted to their sulfinate salts and sulfonyl chlorides.