Brief Note Effects of Diquat on Amphibian Embryo Development

Author Institution: Department of Biology, State University of New York at Fredoni

Fluctuations in the muskellunge ( Esox masquinongy Mitchill) population of Chautauqua Lake, New York

Population and exploitation estimates were made from angler recaptures of Chautauqua Lake muskellunge, Esox masquinongy Mitchill. Fish were tagged during Conservation Department studies in 1941–1946, 1961–1965 and 1976–1978. Population estimates of adult fish ranged from one to seven fish per hectare and angler exploitation rates of tagged fish fluctuated from 3.8% to 14.1%. Relative catch indicators suggest a major decline in the lake's muskellunge population during the last decade. Overexploitation, habitat alteration and interspecific competition with recently introduced fish species were cited as probable causes of the decline.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42642/1/10641_2004_Article_BF00002785.pd

Biological and Structural Characterization of a Host-Adapting Amino Acid in Influenza Virus

Two amino acids (lysine at position 627 or asparagine at position 701) in the polymerase subunit PB2 protein are considered critical for the adaptation of avian influenza A viruses to mammals. However, the recently emerged pandemic H1N1 viruses lack these amino acids. Here, we report that a basic amino acid at position 591 of PB2 can compensate for the lack of lysine at position 627 and confers efficient viral replication to pandemic H1N1 viruses in mammals. Moreover, a basic amino acid at position 591 of PB2 substantially increased the lethality of an avian H5N1 virus in mice. We also present the X-ray crystallographic structure of the C-terminus of a pandemic H1N1 virus PB2 protein. Arginine at position 591 fills the cleft found in H5N1 PB2 proteins in this area, resulting in differences in surface shape and charge for H1N1 PB2 proteins. These differences may affect the protein's interaction with viral and/or cellular factors, and hence its ability to support virus replication in mammals

Characterization of killer immunoglobulin-like receptor genetics and comprehensive genotyping by pyrosequencing in rhesus macaques

<p>Abstract</p> <p>Background</p> <p>Human killer immunoglobulin-like receptors (KIRs) play a critical role in governing the immune response to neoplastic and infectious disease. Rhesus macaques serve as important animal models for many human diseases in which KIRs are implicated; however, the study of KIR activity in this model is hindered by incomplete characterization of <it>KIR </it>genetics.</p> <p>Results</p> <p>Here we present a characterization of <it>KIR </it>genetics in rhesus macaques (<it>Macaca mulatta)</it>. We conducted a survey of <it>KIRs </it>in this species, identifying 47 novel full-length <it>KIR </it>sequences. Using this expanded sequence library to build upon previous work, we present evidence supporting the existence of 22 <it>Mamu-KIR </it>genes, providing a framework within which to describe macaque <it>KIRs</it>. We also developed a novel pyrosequencing-based technique for <it>KIR </it>genotyping. This method provides both comprehensive <it>KIR </it>genotype and frequency estimates of transcript level, with implications for the study of <it>KIRs </it>in all species.</p> <p>Conclusions</p> <p>The results of this study significantly improve our understanding of macaque <it>KIR </it>genetic organization and diversity, with implications for the study of many human diseases that use macaques as a model. The ability to obtain comprehensive KIR genotypes is of basic importance for the study of KIRs, and can easily be adapted to other species. Together these findings both advance the field of macaque KIRs and facilitate future research into the role of KIRs in human disease.</p

KIR Polymorphisms Modulate Peptide-Dependent Binding to an MHC Class I Ligand with a Bw6 Motif

Molecular interactions between killer immunoglobulin-like receptors (KIRs) and their MHC class I ligands play a central role in the regulation of natural killer (NK) cell responses to viral pathogens and tumors. Here we identify Mamu-A1*00201 (Mamu-A*02), a common MHC class I molecule in the rhesus macaque with a canonical Bw6 motif, as a ligand for Mamu-KIR3DL05. Mamu-A1*00201 tetramers folded with certain SIV peptides, but not others, directly stained primary NK cells and Jurkat cells expressing multiple allotypes of Mamu-KIR3DL05. Differences in binding avidity were associated with polymorphisms in the D0 and D1 domains of Mamu-KIR3DL05, whereas differences in peptide-selectivity mapped to the D1 domain. The reciprocal exchange of the third predicted MHC class I-contact loop of the D1 domain switched the specificity of two Mamu-KIR3DL05 allotypes for different Mamu-A1*00201-peptide complexes. Consistent with the function of an inhibitory KIR, incubation of lymphocytes from Mamu-KIR3DL05+ macaques with target cells expressing Mamu-A1*00201 suppressed the degranulation of tetramer-positive NK cells. These observations reveal a previously unappreciated role for D1 polymorphisms in determining the selectivity of KIRs for MHC class I-bound peptides, and identify the first functional KIR-MHC class I interaction in the rhesus macaque. The modulation of KIR-MHC class I interactions by viral peptides has important implications to pathogenesis, since it suggests that the immunodeficiency viruses, and potentially other types of viruses and tumors, may acquire changes in epitopes that increase the affinity of certain MHC class I ligands for inhibitory KIRs to prevent the activation of specific NK cell subsets

GagCM9-Specific CD8+ T Cells Expressing Limited Public TCR Clonotypes Do Not Suppress SIV Replication In Vivo

Several lines of evidence suggest that HIV/SIV-specific CD8+ T cells play a critical role in the control of viral replication. Recently we observed high levels of viremia in Indian rhesus macaques vaccinated with a segment of SIVmac239 Gag (Gag45–269) that were subsequently infected with SIVsmE660. These seven Mamu-A*01+ animals developed CD8+ T cell responses against an immunodominant epitope in Gag, GagCM9, yet failed to control virus replication. We carried out a series of immunological and virological assays to understand why these Gag-specific CD8+ T cells could not control virus replication in vivo. GagCM9-specific CD8+ T cells from all of the animals were multifunctional and were found in the colonic mucosa. Additionally, GagCM9-specific CD8+ T cells accessed B cell follicles, the primary residence of SIV-infected cells in lymph nodes, with effector to target ratios between 20–250 GagCM9-specific CD8+ T cells per SIV-producing cell. Interestingly, vaccinated animals had few public TCR clonotypes within the GagCM9-specific CD8+ T cell population pre- and post-infection. The number of public TCR clonotypes expressed by GagCM9-specific CD8+ T cells post-infection significantly inversely correlated with chronic phase viral load. It is possible that these seven animals failed to control viral replication because of the narrow TCR repertoire expressed by the GagCM9-specific CD8+ T cell population elicited by vaccination and infection