Defense in thrips: forbidding fruitiness of a lactone.

Expulsion of anal fluid from the upturned abdomen was demonstrated to serve a defensive function in the thrips Bagnalliella yuccae. An allomone in the anal exudate was identified as gamma-decalactone, a fruity-smelling compound that repelled potential predators. Chemical defenses may contribute to the ability of thrips to maintain large aggregations.

Dendritic cells transduced with HSV-1 amplicons expressing prostate-specific antigen generate antitumor immunity in mice.

There is currently much interest in generating cytotoxic T lymphocyte (CTL) responses against tumor antigens as a therapy for cancer. This work describes a novel gene transfer technique utilizing dendritic cells (DCs), an extremely potent form of antigen-presenting cell (APC), and herpes simplex virus-1 (HSV-1) amplicons. HSV-1 amplicons are plasmid-based viral vectors that are packaged into HSV-1 capsids, but lack viral coding sequences. Amplicon vectors have been constructed that encode the model tumor antigen ovalbumin (HSV-OVA) and human prostate-specific antigen (HSV-PSA), a protein that is expressed specifically in prostate epithelium and prostate carcinoma cells. These amplicons were packaged using a helper virus-free system that produces vector stocks that are devoid of contaminating cytotoxic helper virus. Transduction of DCs with HSV-OVA or HSV-PSA and co-culture with CTL hybridomas results in specific activation, indicating that transduced DCs express these transgenes and process the tumor antigens for class I MHC presentation to CTL. Mice immunized with HSV-PSA-transduced DCs generate a specific CTL response that can be detected in vitro by a (51)Cr-release assay and are protected from challenge with tumors that express PSA. These results indicate that DCs transduced with HSV-1 amplicon vectors may provide a tool for investigation of the biology of CTL activation by DCs and a new modality for immunotherapy of cancer.

Discordance between expression and genome transfer titering of HSV amplicon vectors: recommendation for standardized enumeration.

Herpes simplex virus-derived amplicon vectors are well suited to the development of gene-based therapy for neurodegenerative diseases. The plasmid-based amplicon vector system allows for facile introduction of transcription units, possesses the potential for carrying gene inserts up to approximately 130 kb in length, and can be packaged into infectious virus devoid of contaminating cytotoxic helper virus. For accurate assessments to be made regarding vector comparison and improvements in vector design, a standard for titering prepared virus stocks must be established. At present, packaged amplicon vectors are routinely titered using reporter gene expression units to quantitate numbers of infectious amplicon virions. The strength of the promoter, sensitivity of detection of the gene product, and choice of titering cell type can greatly influence the apparent numbers of infectious virus particles. This is especially evident when comparisons are made between two amplicon vectors that possess different promoters. To this end, we have developed a new titering method based on a real-time quantitative PCR technique that allows for enumeration of transducing particles. This new approach ensures that amplicon comparison experiments are initiated with equivalent transduction units, thus allowing for a fair assessment of expression and therapeutic efficacy differences.

Gene therapeutic strategies for neuroprotection: implications for Parkinson's disease.

Gene transfer methodologies are being explored as strategies to restore and preserve neuronal function in Parkinson's Disease. This technology represents a new therapeutic modality, holding promise for continuous and localized delivery, of neuroprotective molecules. Two primary approaches for gene transfer have emerged: in vivo and ex vivo. Recent advances in the construction and characterization of gene transfer vectors have generated more efficient vehicles to deliver and express candidate therapeutic genes. Direct gene transfer into the CNS can be achieved with replication-deficient viral vectors of several types: adenovirus, adeno-associated virus, and herpes simplex virus. These vector systems are being evaluated in models of Parkinson's disease. Strategies to deliver genes include those that either augment dopamine biosynthesis or attenuate loss of dopaminergic neurons. A discussion of the various approaches is detailed.

Defensive adaptations of eggs and adults ofGastrophysa cyanea (Coleoptera: Chrysomelidae).

Egg clusters and adults ofGastrophysa cyanea are conspicuous and, like their larvae, are chemically protected. The eggs owe their bright yellow color primarily to ß-carotene and, in addition, contain substantial quantities of oleic acid. At natural concentrations oleic acid effectively deters many species of ants from feeding. The use of fatty acids as deterrents against ants is discussed as a possible widespread phenomenon among insects. During defensive confrontations, adults ofG. cyanea exhibit avoidance behavior and may also feign death. In addition, the adults may autohemmorhage or secrete a fluid from elytral or pronotal pores in response to traumatic stimuli. The secretions are effective against ants and contain a mixture of hydrocarbons as well as terpenoid components. The pattern of ontogenetic modification in the defensive chemical repertoire ofG. cyanea is discussed.

Chemistry and functions of exocrine secretions of the antsTapinoma melanocephalum and T. erraticum.

Volatile constituents produced by ant workers belonging to the speciesTapinoma melanocephalum andT. erraticum have been analyzed by gas chromatography-mass spectrometry. The pygidial (=anal) gland secretion ofT. melanocephalum is fortified with 6-methyl-5-hepten-2-one and actinidine (the mass spectrum of which is corrected in this paper). An unidentified compound was detected in cephalic extracts. The pygidial gland secretion ofT. erraticum was also dominated by 6-methyl-5-hepten-2-one, in addition to two isomers of iridodial, and iridomyrmecin. The sternal glands contained iridodial and C15-C20 hydrocarbons. Workers ofT. melanocephalum effectively utilize their pygidial gland secretions as an alarm-defense system during aggressive encounters with workers ofSolenopsis geminata. 6-Methyl-5-hepten-2-one is active as a releaser of alarm behavior, and actinidine is repellent to workers ofT. melanocephalum. Cephalic extracts possessed attractant and arrestant properties for workers of this species.

Expression of vhs and VP16 during HSV-1 helper virus-free amplicon packaging enhances titers.

Recently developed helper virus-free methods of herpes simplex virus (HSV) amplicon vector packaging provide stocks that are virtually devoid of the cytotoxic component normally associated with traditional helper virus-based packaging methods. These approaches involve cotransfection of amplicon plasmid DNA with either a five-cosmid set or a bacterial artificial chromosome (BAC) that contains the HSV genome without its cognate pac signals. Helper virus-free amplicon packaging produces low-titer stocks (<10(5) expressing particles/ml) that exhibit a high frequency of pseudotransduction. In an effort to enhance amplicon titers, we introduced in trans a genomic copy of the virion host shutoff (vhs) protein-encoding gene UL41 into both cosmid- and BAC-based packaging strategies. Cotransfection of this plasmid with the amplicon and packaging reagents results in a 10-fold higher amplicon titer, and stocks that do not exhibit the pseudotransduction phenomenon. To further enhance packaging efficiency, the HSV transcriptional activator VP16 was introduced into packaging cells 1 day before the packaging components. Pre-loading of packaging cells with VP16 led to an additional enhancement of amplicon titers, an effect that did not occur in the absence of vhs. Increased helper virus-free amplicon titers resulting from these modifications will make in vivo transduction experiments more feasible.

Chemistry of cephalic secretion of fire beeTrigona (Oxytrigona) tataira.

Analysis of the volatile compounds derived from cephalic glands of the fire beeTrigona (Oxytrigona) tataira by GC-MS was undertaken. The following compounds were readily identified: hydrocarbons:n-C11H24,n-C13H28,n-C14H30,n-C15H32,n-C17H36,n-C23H48,n-C15H30,n-C17H34,n-C21 H42, andn-C23H46; carboxylic acids: palmitic acid, linoleic acid, linolenic acid, stearic acid, and oleic acid; carboxylic esters: dodecyl acetate, tetradecyl acetate, hexadecyl acetate, octadecyl acetate, and dodecyl decanoate; monoketones: 5-hepten-2-one, 3-hepten-2-one, 2-heptanone, and 5-nonen-2-one. Two major components of the mixture were identified asE-hepten-2,5-dione andE-3-nonen-2,5-dione. Structures of these novel compounds were suggested by their GC-MS behavior and the GC-MS behavior of their dimethoximes and proved by comparison with authentic synthetic samples. Trace amounts of the corresponding Z isomers and the saturated analogs, heptan-2,5-dione and nonan-2,5-dione, were also found. The possible functions of these glandular constituents are discussed.

Development of herpes simplex virus-1 amplicon-based immunotherapy for chronic lymphocytic leukemia.

Herpes simplex virus (HSV)-based vectors have favorable biologic features for gene therapy of leukemia and lymphoma. These include high transduction efficiency, ability to infect postmitotic cells, and large packaging capacity. The usefulness of HSV amplicon vectors for the transduction of primary human B-cell chronic lymphocytic leukemia (CLL) was explored. Vectors were constructed encoding beta-galactosidase (LacZ), CD80 (B7.1), or CD154 (CD40L) and were packaged using either a standard helper virus (HSVlac, HSVB7.1, and HSVCD40L) or a helper virus-free method (hf-HSVlac, hf-HSVB7.1, and hf-HSVCD40L). Both helper-containing and helper-free vector stocks were studied for their ability to transduce CLL cells, up-regulate costimulatory molecules, stimulate allogeneic T-cell proliferation in a mixed lymphocyte tumor reaction, and generate autologous cytotoxic T lymphocytes (CTLs). Although helper-containing and helper-free amplicon stocks were equivalent in their ability to transduce CLL cells, a vigorous T-cell proliferative response was obtained using cells transduced with hf-HSVB7.1 but not with HSVB7.1. CLL cells transduced with either HSVCD40L or hf-HSVCD40L were compared for their ability to up-regulate resident B7.1 and to function as T-cell stimulators. Significantly enhanced B7.1 expression in response to CD40L was observed using hf-HSVCD40L but not with HSVCD40L. CLL cells transduced with hf-HSVCD40L were also more effective at stimulating T-cell proliferation than those transduced with HSVCD40L stocks and were successful in stimulating autologous CTL activity. It is concluded that HSV amplicons are efficient vectors for gene therapy of hematologic malignancies and that helper virus-free HSV amplicon preparations are better suited for immunotherapy.

Nest plundering allomones of the fire beeTrigona (Oxytrigona) mellicolor.

Ten volatile compounds derived from the cephalic glands of the fire beeTrigona (Oxytrigona)mellicolor were bioassayed for possible allomonal activities facilitating nest plundering. Two diketones, (E)-3-heptene-2,5-dione and (E)-3-nonene-2,5-dione, caused the honeybeeApis mellifera to display avoidance behavior and reduced defensive behavior. These diketones are produced in relatively large quantities in fire-bee cephalic glands.