疾病及处理

In addition to CD4, HIV-1 uses chemokine receptors for entry in their target cells. The most important chemokine receptors in this respect are β-chemokine receptor 5 (CCR5) and α-chemokine receptor 4 (CXCR4). Coreceptor usage is an important feature of the biological phenotype of HIV-1 varia ...

Monocytes play an important, yet only partly understood, role in HIV-1 pathogenesis. Two main subsets of peripheral blood monocytes have been described; the major subset of monocytes are phenotypically characterized as being CD14hi/CD16−, and a minor subset (5–15% of total monocytes in he ...

Differential phenotypes or properties of HIV-1 gene products in primary virus isolates are difficult to assess due to interference by the high degree of sequence variation across the entire genome. Thus, chimeric viruses provide a powerful tool to study the function of single gene products ...

The fitness of human immunodeficiency virus type-1 (HIV-1) appears to be an important piece of the puzzle in understanding the global HIV-1 epidemic and disease progression in infected individuals. We have developed a dual infection/competition assay followed by a sensitive heterodu ...

The development of mixtures of highly processive and high-fidelity thermostable DNA polymerases has enabled the routine recovery of DNA sequences in excess of 25 kb generated by polymerase chain reaction. This powerful tool has been instrumental in the ability to recover virtually ful ...

The genomes of human immunodeficiency virus type 2 (HIV-2), like those of HIV-1, are not only extremely variable but are also highly recombinogenic (1–5). Determination of subtypes based on partial genomes cannot predict the subtype classification of other regions of the genome owing to the fr ...

In retrovirus research, the generation of an infectious molecular clone is a landmark event, opening up new avenues of research using the cloned virus. A full-length proviral plasmid clone of the human T-cell leukemia virus (HTLV) makes possible reproducible viral genetic studies. Howev ...

The molecular engineering of recombinant plasmid DNA clones containing the full-length and replication-competent feline foamy (retro)virus (FFV) proviral genome is described. The methods used to combine subgenomic FFV DNA fragments can be applied to other retrovirus genomes, r ...

Molecular characterization of proteolytic processing of the human spumaretrovirus (HSRV) Gag proteins and the precise determination of cleavage sites was performed. For in vitro processing of recombinant HSRV Gag proteins, a recombinant enzymatically active HSRV protease w ...

HIV-infected monocyte/macrophage-derived cells are believed to play a major role in the spread of HIV through the body. Not only are fresh monocytes and more differentiated macrophages relatively insensitive to the cytopathic effect of HIV, but once infected they can efficiently infe ...

To illustrate the methods employed in gene expression profiling using cDNA microarrays, infection of CD4+ T cell lines with HIV-1LAI is used to identify expression changes relevant to in vitro HIV-1 infection. Cell lines are infected at a high multiplicity of infection to ensure a population of ...

DC-SIGN and DC-SIGNR efficiently bind HIV-1 and other viral as well as nonviral pathogens and assist either cis or trans infection. Both are type II transmembrane proteins that consist of an N-terminal cytoplasmic domain, a repeat region consisting of seven 23-amino-acid tandem repeats, and a C ...

Membranes, in general, constitute the boundary between a cell or a cell compartment and its environment. They are composed of (glyco)lipids and (glyco)proteins, function as permeability barriers, maintain constant ion gradients across the membrane, and guarantee a controlled stea ...

Botulinum neurotoxins produced by strains of the spore-bearing bacterium Clostridium botulinum have long been known to cause a distinctive paralytic disease in humans and animals (1). In recent years, injection of crystalline botulinum toxin type A has been demonstrated to provide re ...

The Shiga family of toxins is comprised of a group of genetically and functionally related molecules whose original family member was described 100 yr ago. Up until the early 1980s this group of toxins was little more than a scientific curiosity without a clear role in disease pathogenesis. Howev ...

The fusion protein toxins that have been described are generally composed of the catalytic and transmembrane domains of a bacterial toxin (e.g., diphtheria toxin or Pseudomonas exotoxin A) to which a polypeptide hormone, growth factor, or single-chain antibody (scFv) is genetically fus ...

Some species and strains within the freshwater cyanobacterial (blue-green algal) genera Microcystis, Oscillatoria (also known as Planktothrix), Anabaena, and Nostoc are known to produce cyclic heptapeptide liver toxins, microcystins. Closely related toxic cyclic pent ape pt ...

The availability of bacterial toxin genes and, in many cases, their atomic structures permits, through properly designed structure-function studies, the precise mapping of the molecular determinants of their activity. The results of such studies are of particular importance for the ...

Pathogenic strains of Staphylococcus aureus produce a large number of exotoxins (1). Among these a family of single-chain leukotoxins of 32–34 kDa has been identified. They include α-toxin (or α-hemolysin), which is probably one of the best studied toxins (2), and a large group of bicomponent tox ...

When a fluorophore absorbs a photon, an electron is excited to a higher energy level. This excited state electron returns to its ground state by one of two competing processes. In radiative de-excitation, a brief relaxation time (about 10-12 s) is followed by the electron’s return to the ground state ac ...