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Jeanette V Bishop

Publications and source records attributed to Jeanette V Bishop.

7 recordsLinked to original sources

Is it possible to develop pan-arthropod vaccines?

Hematophagous arthropods that transmit the etiological agents of arthropod-borne diseases have become the focus of anti-vector vaccines, targeted mainly at components of their saliva and midgut. These efforts have been directed mostly towards developing species-specific vaccines. An alternative is to target cross-reactive epitopes that have been preserved during evolution of the arthropods. The N- and O-linked glycans that are attached to arthropod glycoproteins are one of the potential targets of this pan-arthropod vaccine approach. Here, we discuss how genetically modified Drosophila melanogaster cells can be used to synthesize and to deliver these arthropod glycans to vertebrate hosts.

Animals↗

Novel compounds active against Leishmania major.

Leishmania major is an important trypanosomatid pathogen that causes leishmaniasis, which is a serious disease in much of the Old World. Current treatments include a small number of antimony compounds that, while somewhat effective, are limited by serious side effects. We have screened a small portion of a unique chemical library and have found at least three novel compounds that are effective against L. tarentolae and L. major in vitro and in a murine macrophage model of L. major infection. These compounds were effective in both assays at doses significantly lower than those of sodium stibogluconate (Pentostam) and represent possible candidates for drug development.

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Nanodisk-associated amphotericin B clears Leishmania major cutaneous infection in susceptible BALB/c mice.

Nanometer-scale, apolipoprotein-stabilized phospholipid bilayer disk complexes (nanodisks [ND]) harboring the toxic and poorly soluble antileishmanial agent amphotericin B (AMB) were examined for efficacy in treatment of Leishmania major-infected BALB/c mice (Mus musculus). L. major-infected mice were intraperitoneally (i.p.) treated with AMB-ND in 0-, 1-, and 5-mg/kg doses at 24 h, 48 h, and 4, 7, 14, and 21 days postinfection in two experiments. L. major-infected mice were i.p. treated with phosphate-buffered saline, 5 mg/kg AMB-ND, or 5 mg/kg lipid-associated amphotericin B (liposomal amphotericin B, AmBisome) at 24 h, 48 h, and 10, 20, 30, and 40 days postinfection in one experiment. Parasite numbers, footpad lesion size progression, and development of cytokine responses were assayed at days 7, 15, 30, 50, 140, and 250 or at days 14, 30, 50, 95, and 140 postinfection. Mice administered AMB-ND in 1- or 5-mg/kg doses were significantly protected from L. major, displaying decreases in lesion size and parasite burden, particularly at the 5-mg/kg dosage level. In contrast to the i.p. treated AmBisome group, BALB/c mice treated with i.p. AMB-ND completely cleared an L. major infection by 140 to 250 days postinfection, with no lesions remaining and no parasites isolated from infected animals. Restimulated mixed lymphocyte culture cytokine responses (interleukin-4 [IL-4], IL-12, IL-10, NO, and gamma interferon) were unchanged by AMB-ND administration compared to controls. The marked clearance of Leishmania parasites from a susceptible strain of mice without an appreciable change in the cytokine response suggests that AMB-ND represent a potentially useful formulation for treatment of intrahistiocytic organisms.

Amphotericin B↗

Salivary gland extracts of Culicoides sonorensis inhibit murine lymphocyte proliferation and no production by macrophages.

Culicoides biting midges serve as vectors of pathogens affecting humans and domestic animals. Culicoides sonorensis is a vector of several arboviruses in North American that cause substantial economic losses to the US livestock industry. Previous studies showed that C. sonorensis saliva, like the saliva of many hematophagous arthropods, contains numerous pharmacological agents that affect hemostasis and early events in the inflammatory response, which may enhance the infectivity of Culicoides-borne pathogens. This paper reports on the immunomodulatory properties of C. sonorensis salivary gland extracts on murine immune cells and discusses the possible immunomodulatory role of C. sonorensis saliva in vesicular stomatitis virus infection of vertebrate hosts. Splenocytes treated with C. sonorensis mitogens were significantly affected in their proliferative response, and peritoneal macrophages secreted significantly less NO. A 66-kDa glycoprotein was purified from C. sonorensis salivary gland extract, which may be in part responsible for these observations and may be considered as a vaccine candidate.

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Multiclonal pattern of Jaagsiekte sheep retrovirus integration sites in ovine pulmonary adenocarcinoma.

Insertional mutagenesis and envelope (Env)-mediated oncogenesis are hypothesized mechanisms by which Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma (OPA). Twenty-eight JSRV integration sites in lung tumors (LTs) from four sheep with OPA were cloned and sequenced by a multiple step gene walking technique. Using nested PCR, clonal expansion of these integration sites could be detected, if at all, only in the localized regions of LT from which the integration sites were derived. One sheep had a viral integration site in a sequence with 85 and 81% identity, respectively, over 100 bp to exon 2 of the human and mouse receptor protein tyrosine phosphatase gamma genes. Clonal integration of Jaagsiekte sheep retrovirus in this gene was demonstrated by nested PCR and Southern blot hybridization in the DNA sample from which the integration site was cloned, but not in other LT or kidney DNA samples from the same sheep. OPA may develop from multiple independent oncogenic events and a role for insertional mutagenesis cannot be ruled out.

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Characterization of an I-E-restricted, gp63-specific, CD4-T-cell clone from Leishmania major-resistant C3H mice that secretes type 2 cytokines and exacerbates infection with L. major.

A T-cell clone (designated KLmB-3) was derived from resistant C3H mice 2 weeks after infection with Leishmania major. KLmB-3 was a CD4-T-cell clone that utilized the V beta 8.1 T-cell receptor. When adoptively transferred to naive C3H mice, KLmB-3 unexpectedly exacerbated infection with L. major (it increased the cutaneous lesion size and the parasite burden within the lesion). The ability of KLmB-3 to exacerbate disease correlated with its ability to produce the type 2-associated cytokines interleukin-4 (IL-4), IL-5, IL-10, and transforming growth factor beta. Interestingly, KLmB-3 was specific for an epitope in the amino-terminal end of the L. major surface gp63 zinc metalloproteinase (leishmanolysin) that has been shown to be capable of inducing a protective immune response. Moreover, KLmB-3 was activated when this epitope was presented in the context of H-2 I-E rather than H-2 I-A.

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Analysis of integration sites of Jaagsiekte sheep retrovirus in ovine pulmonary adenocarcinoma.

Ovine pulmonary adenocarcinoma (OPA) is an infectious lung tumor of sheep caused by Jaagsiekte sheep retrovirus (JSRV). To test the hypothesis that JSRV insertional mutagenesis is involved in the oncogenesis of OPA, we cloned and characterized 70 independent integration sites from 23 cases of OPA. Multiple integration sites were identified in most tumors. BLAST analysis of the sequences did not disclose any potential oncogenic motifs or any identical integration sites in different tumors. Thirty-seven of the integration sites were mapped to individual chromosomes by PCR with a panel of sheep-hamster hybrid cell lines. Integration sites were found on 20 of the 28 sheep chromosomes, suggesting a random distribution. However, four integration sites from four different tumors mapped to chromosome 16. By Southern blot hybridization, probes derived from two of these sites mapped to within 5 kb of each other on normal sheep DNA. These sites were found within a single sheep bacterial artificial chromosome clone and were further mapped to only 2.5 kb apart, within an uncharacterized predicted gene and less than 200 kb from a mitogen-activated protein kinase-encoding gene. These findings suggest that there is at least one common integration site for JSRV in OPA and add weight to the hypothesis that insertional mutagenesis is involved in the development of this tumor.

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