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B Annis

Publications and source records attributed to B Annis.

13 recordsLinked to original sources
PubMed1998

Immune modulation of human B lymphocytes by gene transfer with recombinant Epstein-Barr virus amplicons.

We described previously a novel mode of gene transfer by infection of human B lymphocytes with recombinant Epstein-Barr virus (EBV) amplicons. This system was explored for its potential use in expressing various recombinant genes, including the cytokine IL-4, the HIV envelope glycoprotein (gp120) and a suicide and gag gene. Recombinant genes were present as multiple copy episomes and stable, high level recombinant gene expression could be detected by antigenic and functional assays. Amplicon-infected B cells secreted high levels of recombinant cytokine and efficiently presented recombinant antigens through classes I and II MHC-restricted antigen processing pathways. Thus, recombinant EBV amplicons can be used to express components of the immune system or heterologous genes for immune recognition in human B cells. Combining gene transfer with EBV infection may provide unique advantages for in vitro and in vivo gene transfer.

Antigen Presentation↗
PubMed1998

Infection of human B lymphocytes with lymphocryptoviruses related to Epstein-Barr virus.

Lymphocryptoviruses (LCVs) naturally infecting Old World nonhuman primates are closely related to the human LCV, Epstein-Barr virus (EBV), and share similar genome organization and sequences, biologic properties, epidemiology, and pathogenesis. LCVs can efficiently immortalize B lymphocytes from the autologous species, but the ability of a given LCV to immortalize B cells from other Old World primate species is variable. We found that LCV from rhesus monkeys did not immortalize human B cells, and EBV did not immortalize rhesus monkey B cells. In this study, baboon LCV could not immortalize human peripheral blood B cells but could readily immortalize rhesus monkey B cells. Thus, efficient LCV-induced B-cell immortalization across distant Old World primate species appears to be restricted by a species-specific block. To further characterize this species restriction, we first cloned the rhesus monkey LCV major membrane glycoprotein and discovered that the binding epitope for the EBV receptor, CD21, was highly conserved. Stable infections of human B cells with recombinant amplicons packaged in rhesus monkey or baboon LCV envelopes were also consistent with a species-restricted block occurring after virus binding and penetration. Transient infections of human B cells with simian LCV resulted in latent LCV EBNA-2 gene expression and activation of cell CD23 gene expression. EBV-immortalized human B cells could be coinfected with baboon LCV, and the simian virus persisted and replicated in human B cells. Thus, several lines of evidence indicate that the species restriction for efficient LCV-induced B-cell immortalization occurs beyond virus binding and penetration. This has important implications for the study of LCV infection in Old World primate models and for human xenotransplantation where simian LCVs may be inadvertently introduced into humans.

Amino Acid Sequence↗
PubMed1997

An animal model for acute and persistent Epstein-Barr virus infection.

Epstein-Barr virus (EBV) is a human lymphocryptovirus that causes infectious mononucleosis, persists asymptomatically for life in nearly all adults, and is associated with the development of B cell lymphomas and nasopharyngeal carcinomas. A highly similar rhesus lymphocryptovirus naturally endemic in rhesus monkeys was used to orally infect naïve animals from a pathogen-free colony. This animal model reproduced key aspects of human EBV infection, including oral transmission, atypical lymphocytosis, lymphadenopathy, activation of CD23(+) peripheral blood B cells, sustained serologic responses to lytic and latent EBV antigens, latent infection in the peripheral blood, and virus persistence in oropharyngeal secretions. This system may be useful for studying the pathogenesis, prevention, and treatment of EBV infection and associated oncogenesis.

Animals↗
PubMed1996

Comparative analysis identifies conserved tumor necrosis factor receptor-associated factor 3 binding sites in the human and simian Epstein-Barr virus oncogene LMP1.

Nonhuman primates are naturally infected with a B-lymphotropic herpesvirus closely related to Epstein-Barr virus (EBV). These simian EBV share considerable genetic, biologic, and epidemiologic features with human EBV, including virus-induced tumorigenesis. However, latent, transformation-associated viral genes demonstrate marked sequence divergence among species despite the conserved functions. We have cloned the latent membrane protein 1 (LMP1) homologs from the simian EBV naturally infecting baboons (cercopithicine herpesvirus 12, herpesvirus papio) and rhesus monkeys (cercopithicine herpesvirus 15) for a comparative study with the human EBV oncogene. The transmembrane domains are well conserved, but there is striking sequence divergence of the carboxy-terminal cytoplasmic domain essential for B-cell immortalization and interaction with the tumor necrosis factor receptor signaling pathway. Nevertheless, the simian EBV LMP1s retain most functions in common with EBV LMP1, including the ability to induce NF-(kappa)B activity in human cells, to bind the tumor necrosis factor-associated factor 3 (TRAF3) in vitro, and to induce expression of tumor necrosis factor-responsive genes, such as ICAM1, in human B lymphocytes. Multiple TRAF3 binding sites containing a PXQXT/S core sequence can be identified in the simian EBV LMP1s by an in vitro binding assay. A PXQXT/S-containing sequence is also present in the cytoplasmic domain of the Hodgkin's disease marker, CD30, and binds TRAF3 in vitro. The last 13 amino acids containing a PXQXT/S sequence are highly conserved in human and simian EBV LMP1 but do not bind TRAF3, suggesting a distinct role for this conserved region of LMP1. The conserved TRAF3 binding sites in LMP1 and the CD30 Hodgkin's disease marker provides further evidence that a TRAF3-mediated signal transduction pathway may be important in malignant transformation.

Amino Acid Sequence↗
PubMed1995

Tap-1 and Tap-2 gene therapy selectively restores conformationally dependent HLA Class I expression in type I diabetic cells.

Genetic susceptibility to many autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM) is statistically linked to the HLA class II region of chromosome 6. However, a distinguishing feature of patients with HLA class II-linked autoimmune disease is an abnormally low density of conformationally correct, self-peptide filled HLA class I molecules on the lymphocyte cell surface. The transporters associated with antigen processing (Tap-1 and Tap-2) are essential for normal class I expression and presentation of intracellular peptides, and these genes are located within the HLA class II region. The aims of this project were to determine if Tap genes could be implicated in the defective class I expression associated with IDDM by using a novel Epstein-Barr virus (EBV)-mediated gene transfer system to introduce a cloned, normal Tap-2 or Tap-1 gene into B cell lines from normal and IDDM patients and analyzing the effect on conformationally dependent class I expression. The results show that Tap-2 gene transfer in B cells from 40% of randomly selected IDDM patients increased expression of conformationally correct, cell-surface class I molecules to levels comparable with similarly treated B cells from normal control individuals. B cells from another 40% of IDDM patients responded to Tap-1 gene transfer. These effects were specific because B cells from normal individuals did not respond to Tap-1 or Tap-2 gene transfer with increased class I expression, and B cells from IDDM patients responding to Tap-2 gene transfer did not respond to Tap-1 gene transfer and vice versa. Thus, these complementation studies identify distinct, non-overlapping subsets of IDDM patients whose class I defect in B cells can be reversed by Tap-1 or Tap-2 gene transfer. The increase in class I expression induced by Tap gene transfer is associated with a reduction in the number of peptide-empty class I molecules as demonstrated by the response to exogenous peptide loading. Furthermore, the increase in self-peptide filled class I molecules induced by Tap gene transfer into B cells from IDDM patients is associated with restored antigen presentation to autologous T cells. These studies conclude that Tap gene dysfunctions may contribute to the defect in class I phenotype and antigen presentation demonstrated by IDDM patients. Defective presentation of self-peptides by antigen presenting cells can lead to the failed T cell education and tolerance to self antigens evident in IDDM. These studies functionally identify HLA class II region genes that contribute to an immunologic defect in IDDM.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

5' Coding and regulatory region sequence divergence with conserved function of the Epstein-Barr virus LMP2A homolog in herpesvirus papio.

B-lymphotropic herpesviruses naturally infecting Old World primates share biologic, epidemiologic, pathogenic, and molecular features with the human pathogen Epstein-Barr virus (EBV). These related gammaherpesviruses have colinear genomes with considerable nucleotide homology. The replicative cycle genes share a high degree of homology across species, whereas the transformation-associated EBV latent genes appear to be much more divergent. For example, the EBV BamHI Nhet fragment, which encodes all or part of the EBV latent infection membrane proteins, cross-hybridizes poorly to DNA from nonhuman primate B-lymphotropic herpesviruses. A viral DNA fragment corresponding to this region of the EBV genome was isolated from the baboon B-lymphotropic herpesvirus, herpesvirus papio, and used to clone a herpesvirus papio cDNA corresponding to EBV LMP2A. At least three tyrosine kinase interaction motifs are conserved despite significant amino acid divergence of the herpesvirus papio LMP2A first exon from the EBV homolog. Functionally, the herpesvirus papio LMP2A is tyrosine phosphorylated and induces tyrosine phosphorylation of cell proteins similar to EBV LMP2A. The 12 hydrophobic LMP2 transmembrane domains are well conserved. Two CBP (Jk) binding sites important for EBNA-2-induced transactivation of the LMP2A promoter are also present in the herpesvirus papio LMP2A promoter, and the simian LMP2A promoter is also responsive to EBV EBNA-2-induced transactivation in human B cells. Thus, transcriptional regulation, splicing, kinase interaction sites, and tyrosine phosphorylation of the LMP2A homologs have been conserved despite significant sequences heterogeneity in the preterminal repeat regions of these human and nonhuman primate EBVs. The conservation of the LMP2 gene, despite its apparent nonessential role for in vitro EBV infection, suggests an important role for LMP2A in vivo. The similarities between these human and simian B-lymphotropic herpesviruses, and the LMP2 genes in particular, suggest that the function of LMP2 in vivo could be addressed by using recombinant LMP2A-mutant simian viruses and experimental infection of Old World primates.

Amino Acid Sequence↗
PubMed1991

Comparison of the effectiveness of two deet formulations against Aedes albopictus in the Philippines.

The effectiveness of 2 formulations of deet was tested in the Philippines against Aedes albopictus. A new military issue extended duration repellent formulation (EDRF) was compared with the older standard liquid formulation. Consistently fewer mosquitoes landed on subjects treated with the EDRF than on those treated with the liquid formulation for up to 12 h post-application. However, the difference between the 2 formulations was not statistically significant. Both treatments were significantly different from untreated control subjects. The same was true when other day-biting mosquitoes including Armigeres subalbatus, Ar. flavus and Ae. vexans were analyzed as a group.

Aedes↗
PubMed1990

Toxorhynchites amboinensis larvae released in domestic containers fail to control dengue vectors in a rural village in central Java.

The efficacy of Toxorhynchites amboinensis larvae for control of dengue vectors in household water storage containers was tested in a rural village in Central Java, Indonesia. Concrete cisterns and clay jars were the most common types of containers used for long-term water storage, although smaller numbers of metal drums were also used. All containers in use in the village received 5-10 second- or third-instar Tx. amboinensis larvae biweekly for 7 months. Vector surveillance (adult and larval) was conducted biweekly between treatments. No differences in man-biting rates or larval population indices were noted between the treatment and control areas. It is hypothesized that the multiplicity of larval habitats in this rural area accounted for the lack of impact of predator releases, which were directed solely toward artificial containers.

Aedes↗
PubMed1990

Comparison of the effectiveness of two formulations of deet against Anopheles flavirostris.

The effectiveness of 2 formulations of deet (diethylmethylbenzamide) was tested against the principal vector of malaria in the Philippines, Anopheles flavirostris. A new extended duration repellent formulation (EDRF) was compared with the standard military-issue liquid formulation. The EDRF was significantly more effective than the liquid formulation between 6 and 12 h post-application. There was no difference between the 2 formulations in the first 6 h following application, or between 12 and 15 h post-application. The continued usefulness of the liquid formulation is discussed in light of these results.

Animals↗
PubMed1989

Suppression of larval Aedes aegypti populations in household water storage containers in Jakarta, Indonesia, through releases of first-instar Toxorhynchites splendens larvae.

Weekly releases of first-instar Toxorhynchites splendens larvae were made in household water storage containers in a neighborhood in Jakarta, Indonesia, between April 1987 and April 1988. A single larva was placed in each container surveyed. Forty-one percent of all containers in the treatment area were treated each week and the average container was treated once every 2.4 weeks. Aedes aegypti populations were suppressed but not controlled by treatment. It is hypothesized that first-instar Toxorhynchites larvae were poor control agents due to their inability to withstand periods of starvation and to their accidental removal from containers during the act of water consumption.

Aedes↗