attachment

Examples of attachment in the following topics:

• Attachment and Entry of Herpes Simplex

  • Herpes simplex virus attaches to a host's cells with viral envelope glycoproteins, which then allows entry of the viral capsid into the host cell.
  • The genome encodes for 11 different glycoproteins, four of which, gB, gC, gD and gH, are involved in viral attachment.
  • The receptor provides a strong, fixed attachment to the host cell.
  • Herpes simplex virus attaches to host cell surface receptors using glycoproteins.
  • Following attachment, the viral envelope fuses with the host cell membrane and the viral capsid gains entry into the cell.

• HIV Attachment and Host Cell Entry

  • The attachment and fusion of HIV virons to host cells are crucial to HIV infection.
  • After attachment, the HIV viron must next fuse with the host cell.
  • The first step in fusion begins after the attachment of the CD4 binding domains of gp120 to CD4.
  • Because HIV attachment is critical for the HIV replication cycle, understanding the specific mechanisms through which HIV attachment occurs has implications for potential treatments of HIV.
  • Define the unique aspects of HIV attachment and host cell entry

• Cryptosporidiosis

  • The oocysts, once ingested, excyst within the small intestine and release sporozoites which attach to the microvilli.
  • The trophozoites then develop into Type 1 and Type 2 merozoites which can either cause auto infection (Type 1) or undergo releasal and attach the epithelial cells (Type 2).
  • Once released and attached, they will either develop in macrogamonts or microgamonts which correlate with male and female forms.
  • The oocysts can initiate infections by attaching to the brush border of the small intestine and attacking the epithelial cells.

• Classification and Identification of Helminths

  • The classification and identification of helminths are dependent on numerous factors including body shape, body cavity, body covering, digestive tubing, sex and type of attachment organs.
  • They utilize suckers or bothridia, and rostellum with hooks for an attachment organ .
  • Trematodes are hermaphroditic and utilize oral suckers, ventral suckers or acetabulum for attachment organs.
  • Lastly, their attachment organs range from lips, teeth, filariform extremities and dentary plates.

• Attachment and Entry to the Host Cell

  • For influenza viral propagation to begin, there first must be viron attachment and entry into a host cell.
  • The glycoprotein responsible for attachment on the surface of an influenza viral particle is hemagglutinin (HA).
  • Of special note is HA (hemagglutinin), the glycoprotein critical for influenza attachment and entry into host cells.
  • Explain the role of hemagglutinin in the attachment and entry processes of influenza virus

• Biofilms

  • Microbes form a biofilm in response to many factors, including cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or exposure of planktonic cells to sub-inhibitory concentrations of antibiotics.
  • Formation of a biofilm begins with the attachment of free-floating microorganisms to a surface.
  • Some species are not able to attach to a surface on their own but are able to anchor themselves to the matrix or directly to earlier colonists.
  • Stage 1: initial attachment; stage 2: irreversible attachment; stage 3: maturation I; stage 4: maturation II; stage 5: dispersion.

• Virus Attachment and Genome Entry

  • Penetration follows attachment: Virions enter the host cell through receptor-mediated endocytosis or membrane fusion.
  • There are six basic stages in the life cycle of viruses: attachment, penetration, uncoating, replication, assembly of viral particles, and release.

• Characteristics of Helminths

  • Helminths share numerous characteristics that contribute to their parasitic quality including the presence of attachment organs.
  • These attachment organs include bothria (sucking grooves: Cestodes or tapeworms, which may also have a rostellum (crown of thorns with hooks); Old World Hookworms: cutting teeth; New World Hookworms: cutting plate.
  • These attachment organs allow these particular helminths to reside within their human host.

• Bacterial Differentiation

  • For instance, rod shapes may allow bacteria to attach more readily in environments with shear stress (e.g., in flowing water).
  • Cocci may have access to small pores, creating more attachment sites per cell and hiding themselves from external shear forces.
  • Bacterial morphology changes help to optimize interactions with cells and the surfaces to which they attach.
  • Moreover, the filamentation benefits bacterial cells attaching to a surface because it increases specific surface area in direct contact with the solid medium.

• Reporter Fusions

  • In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to a regulatory sequence of another gene of interest in bacteria, cell culture, animals, or plants .
  • In these cases the reporter is directly attached to the gene of interest to create a gene fusion.
  • The resulting protein-GFP hybrid transcribed from the reporter construct now has a protein attached to GFP.
  • In the case of GFP which fluorescence one can deduce that the attached protein is wherever the fluorescence is.
  • In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to a regulatory sequence of another gene of interest in bacteria, cell culture, animals, or plants