Protected areas and freshwater conservation: a survey of protected area managers in the Tennessee and Cumberland River Basins, USA.

As the scientific community has highlighted the plight of freshwater species, there have been increasing calls for protected area (PA) designation and management specific to the conservation of aquatic species and ecosystems. In this study we examined PA management in one relatively well-resourced (high levels of financial and technical resources) part of the world: the Tennessee and Cumberland River Basins, USA. We asked managers their perceptions about the current status of freshwater ecosystems within PAs, the sources of stress that are degrading freshwater ecosystem integrity, the degree to which PAs address these stressors, and the availability of technical, human, and financial resources for management activities that benefit freshwater ecosystems and the species they support. Managers generally perceive that freshwater ecosystems within PAs are under low levels of stress, with less than half reporting any alteration to ecosystem integrity, and very few reporting alterations at medium or high levels. Most PAs have fewer resources dedicated to freshwater conservation and management than to other activities, and some PAs completely lack resources for freshwater management. We recommend a review of every PA's goals and objectives and any needed updates to include the conservation of freshwater ecosystems. We also recommend an analysis to determine the most pressing stressors to aquatic life within each PA, stemming from sources both from within and outside of a PA's boundaries, and that this information be used to guide future management. Finally, we suggest that management resources be prioritized for PAs that include large portions of the catchments of their freshwater systems; that can address the dominant sources of stress within the PA; or that contain representative ecosystems, species assemblages or populations of rare, endemic, and threatened species.

Characterization of T cell responses to herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) using a TNF-beta ELISpot cytokine assay.

We examined the suitability of a TNF-beta cytokine ELISpot assay for assessing various aspects of the T cell response to herpes simplex viruses. The number of T cells responding to HSV-1 or HSV-2 was measured by TNF-beta ELISpot assay. The number of T cells producing TNF-beta in response to HSV-1 was high, ranging from 76 to 222 per 10(5). HSV-1-specific TNF-beta-secreting responder cell frequencies fluctuated over time in individual donors. Comparable fluctuations were not observed in the T cell frequencies to phytohemaglutinin (PHA). Responder cell frequencies to glycoproteins gB and gD of HSV-2 accounted for a large number of the HSV-2-specific T cells as measured using the TNF-beta ELISpot assay. Type-specific and type-common components of the T cell response to HSV-1 and HSV-2 could be estimated with this assay. Type-common responder cells typically accounted for 25-30%. Finally, CD4+ and CD8+ TNF-beta-producing T cells were stimulated by HSV-1 at a CD4:CD8 ratio of 2:1, indicating that both major subsets of T lymphocytes are activated by HSV.

Inhibition of HSV-1-specific cytotoxic T lymphocytes by recombinant-derived gp120 of HIV-1.

The ability of human immunodeficiency virus type-1 (HIV-1) and recombinant HIV-1 gp120 to prevent target cell lysis by herpes simplex virus type 1 (HSV-1)-specific cytotoxic T lymphocytes (CTL) was assessed by limiting dilution analysis. Live and inactivated HIV-1 as well as recombinant-derived gp120 all substantially inhibited HSV-1-specific CTL. Soluble CD4 antigen reversed the inhibition by gp120 when simultaneously added with gp120 to the assay. In addition, the monoclonal anti-CD4 antibody a-Leu3a mimicked the effects of gp120 in these experiments. These data suggest that the observed decrease in measurable CTL activity is caused by direct or steric hindrance of the CD4-class II major histocompatibility complex interaction between the effector and target cells.

Inhibition of the in vitro generation of class II-restricted, HSV-1-specific, CD4+ CTL by HIV-1.

Previously, we demonstrated that cultures of human peripheral blood lymphocytes (PBL) stimulated with herpes simplex virus type 1 (HSV-1) generate antigen-specific, major histocompatibility complex (MHC) restricted cytotoxic T lymphocytes (CTL) that tend to be CD4+ and restricted to HLA-DR antigens. In this study, we present evidence that when HSV-1 stimulated human peripheral blood lymphocytes (PBL) are cocultured with human immunodeficiency virus type 1 (HIV-1), the generation of CD4+, DR-restricted CTL during the 5-day culture period is inhibited. In contrast, HIV-1 had no effect on either natural killer (NK) activity, or on the unrestricted NK-like killers which are often detected in HSV-1-stimulated cultures after the depletion of CD16+ cells. HIV-1 also failed to inhibit the generation of CTL against Epstein-Barr virus (EBV), a response that principally involves CD8+, CD4-, class I-restricted killers.