Virus : HIV by Nor Amira Binti Mohd Amin https://padlet.com/myaaamin98/9ihbdgpduxzj Let's play with virus en-us 2017-12-04 01:35:44 UTC 2026-01-18 12:26:56 UTC hello@padlet.com myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212687197 1. Poh Jia Shin
2. Ain Nuur Khalida 
3. Amyza Azwa 
4. Nor Amira
5. Nur Aqilah]]> 2017-12-04 01:40:12 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212687197 Classification pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690038 Group:
Group VI (ssRNA-RT)

Order:
Unassigned

Family:
Retroviridae

Subfamily:
Orthoretrovirinae
Genus:
Lentivirus

]]> 2017-12-04 02:05:29 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690038 myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690101 Scanning electron micrograph of HIV-1 (in green) budding from cultured lymphocyte. Multiple round bumps on cell surface represent sites of assembly and budding of virions.]]> 2017-12-04 02:06:01 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690101 What is HIV myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690214 The human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and over time acquired immunodeficiency syndrome (AIDS). AIDS is a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype. Infection with HIV occurs by the transfer of blood, pre-ejaculate, semen, vaginal fluids, or breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells.]]> 2017-12-04 02:07:22 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690214 HIV myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690297 https://www.medicalnewstoday.com/articles/17131.php

]]> 2017-12-04 02:08:18 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690297 Infection of Human Cells myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690436 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4924471/

]]> 2017-12-04 02:09:28 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690436 Physical Characteristics pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690500 An HIV molecule is about 1/20th the size of E. coli and 1/70th of the size of a typical white blood cell. The virus is surrounded by a membrane made of fatty materials that are dotted with small spikes made of proteins. The viral genetic material is inside the membrane. The virus also contains several proteins needed to replicate.

]]> 2017-12-04 02:09:57 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690500 Infection of Human Cells myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690960 The initial steps of infection of a cell are characterised by complex protein-protein interactions. The surface glycoprotein gp120 of the mature HIV particle binds to the CD4 receptor on the host cell. All CD4-positive cells such as T helper cells, macrophages, dendritic cells and astrocytes are susceptible to HIV. After attachment to the CD4 molecule via the C4-domain of gp120, a conformational change in CD4 and gp120 occurs, opening up an additional site for gp120 to enable binding to the co-receptor, i.e. chemokine receptor 5 (CCR5) or chemokine receptor 4 (CXCR4 or fusin) on the cell surface . Binding of gp120 to CD4 and to the co-receptor triggers an additional conformational change in gp120 and subsequently in gp41 . The N-terminus of gp41 is presented on the viral membrane, forms a channel and, due to its high hydrophobicity, inserts into the plasma membrane of the target cell. Fusion of cell membrane and viral envelope is then completed.Fusion of the viral and cellular membranes leads to translocation of the viral capsid into the cytoplasm. The capsid is taken up by an endosome, and a change in the pH value in the phagosome induces the release of the capsid contents into the cytoplasm . Activation of reverse transcriptase (RT) takes place in the cytoplasm. HIV RT transcribes the single-strand HIV RNA genome into DNA (complementary DNA or cDNA). In parallel to DNA synthesis, the RNA strand is degraded enzymatically by RNase H, followed by conversion of single-stranded cDNA into double-stranded DNA (proviral DNA) by the DNA-dependent DNA polymerase activity of RT . This proviral DNA is transported via nucleopores into the cell nucleus in the form of a complex consisting of the integrase (IN) and linear or circular proviral DNA. The integrase then inserts at random the proviral genome into the human host cell genome. Integration of the proviral DNA finalises the HIV infection of the cell and the establishment of a persistent infection.

]]> 2017-12-04 02:14:15 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212690960 Life Cycle pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212691166 HIV has a complex life cycle, according to The Body, a physician-run website dedicated to providing information about HIV. The first step is binding to the CD4 protein, after which the virus fuses its membrane with that of the CD4 positive T cell. Once the virus has gained access to the cell's interior, it activates some of the proteins it needs for reproduction using an enzyme called protease. Next it converts its genetic material from RNA to DNA. The virus then incorporates this newly formed DNA into genes in the T cell, which causes the T cell to make more copies of the virus. Once the resources of the T cell have been exhausted, the many copies of the virus leave, via a process known as budding.

]]> 2017-12-04 02:15:52 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212691166 General characteristic pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212692191 As a virus, the human immunodeficiency virus is an intracellular parasite meaning that it requires a host cell to survive and reproduce.  Unfortunately for those infected it targets immune cells specifically including CD4 T-helper cells, that of which are crucial for the host’s immune response.  There are two known variants of HIV; HIV-1 and HIV-2.  Unless otherwise stated HIV in the United States is typically referring to the HIV-1 variant which is much more virulent and aggressive, and as such has spread across the entire globe.  HIV-2 on the other hand is much tamer than its brother and is less infectious.  Consequently, the HIV-2 strand is mainly confined to its origin of West Africa; although, a few known cases have been identified in the United States.]]> 2017-12-04 02:23:43 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212692191 Structure of HIV myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699597
  • The lipid membrane (light yellow) is a fat bi-layer that is recruited from the cell membrane of a cell a new virion “buds” from; it accounts for about 30% of the total weight of the virion (Gag, described in the HIV Genome Glossary entry, accounts for about another 50%) and contains all of the virion except the glycoprotein spikes named gp160 (comprising the HIV protein Env). Each gp160 spike splits to form two glycoproteins, the docking protein gp120 (purple elongated ovals) on the outside of the virion’s membrane and the transmembrane protein gp41 (elongated green ovals) that actually pierces the viral membrane; gp160 is the part of an HIV virion that attaches it to a target cell, most often a CD4+ T cell; each of gp120 and gp41 is a trimer, i.e., there are three copies of each bound together; when a virion attaches to a target CD4+ T cell, the trimers open to create a mechanism that, along with the cell’s CD4 receptor and either of the two co-receptors CCR5 or CXCR4, accomplishes entry into the cell;
  • Inside the virus membrane is a protein layer called the matrix (light blue) made up of matrix protein or p17, which contains essential proteins and the nucleus;
  • Protease (black squares with light blue inside) is an enzyme that cleaves newly formed HIV polyproteins during viral replication into their constituent protein components;
  • The capsid (dark blue) is the outer membrane of the virion’s nucleus and is composed of molecules of a protein known as p24; the capsid’s contents are as follows: 
    • The genome (black lines sticking out of the nucleocapsids) consists of two single strands of RNA, as described in the HIV Genome Glossary entry partially encased in the nucleocapsids (grayish green);
    • The capsid also contains several proteins, namely, reverse transcriptase (RT), integrase (IN), Vif, Vpr, Nef, and p7, which are described below. 
      • Reverse transcriptase (RT) (black circles with red insides) is the enzyme responsible for reverse transcribing HIV RNA to HIV proviral DNA;
      • Integrase (IN) (light blue open circles) is the enzyme responsible for integrating the reverse-transcribed DNA into the host cell’s DNA;
      • Nef (negative regulatory factor) (one of the circles in the black bracket) is a small protein that causes numerous changes in an infected cell to adapt it to reproducing HIV;
      • Vpr (viral protein R) (another of the circles in the black bracket) is a small protein that is essential to HIV viral replication in non-dividing cells, such as macrophages;
      • Vif (viral infectivity factor) (another of the circles in the black bracket) is a small protein that is essential to HIV viral replication; and
      • p7 (another of the circles in the black bracket) is a peptide that facilitates reverse transcription.

    • ]]>     2017-12-04 03:33:08 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699597     Asymptomatic HIV pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699610 In many cases, after the initial symptoms disappear, there will not be any further symptoms for many years.

    During this time, the virus carries on developing and damaging the immune system and organs. Without being on medications to stop HIV's replication, this process can take up to 10 years on average. The infected person often experiences no symptoms, feels well, and appears healthy.
    ]]>     2017-12-04 03:33:13 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699610     HIV life cycle myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699726 The seven stages of the HIV life cycle are:
    1) binding
    2) fusion
    3) reverse transcription
    4) integration
    5) replication
    6) assembly
    7) budding]]>     2017-12-04 03:34:32 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699726     Late-stage HIV infection pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699822 If left untreated, HIV weakens the ability to fight infection. The person becomes vulnerable to serious illnesses. This stage of infection is known as AIDS.

    Symptoms of late-stage HIV infection may include:

    • blurred vision
    • diarrhea, which is usually persistent or chronic
    • dry cough
    • fever of above 100 °F (37 °C) lasting for weeks
    • night sweats
    • permanent tiredness
    • shortness of breath (dyspnea)
    • swollen glands lasting for weeks
    • unintentional weight loss
    • white spots on the tongue or mouth
    During late-stage HIV infection, the risk of developing a life-threatening illness is much greater. Life-threatening illnesses may be controlled, avoided,and/or treated with proper medications, often including HIV treatment.

    ]]>     2017-12-04 03:35:38 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699822     image myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699950 2017-12-04 03:37:03 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212699950 Symptoms of early HIV infection pohjiashin https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700043 Many people with HIV have no symptoms for several months to even years after becoming infected. Others may develop symptoms similar to flu, usually 2-6 weeks after catching the virus.

    The symptoms of early HIV infection may include:

    • fever
    • chills
    • joint pain
    • muscle aches
    • sore throat
    • sweats (particularly at night)
    • enlarged glands
    • a red rash
    • tiredness
    • weakness
    • unintentional weight loss
    ]]>     2017-12-04 03:37:56 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700043     HIV Replication Cycle myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700222 2017-12-04 03:39:52 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700222 link for HIV life cycle myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700827 https://aidsinfo.nih.gov/understanding-hiv-aids/fact-sheets/19/73/the-hiv-life-cycle]]> 2017-12-04 03:46:36 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212700827 myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212701035 https://www.projectinform.org/glossary/hiv-structure-function/

    ]]>     2017-12-04 03:48:31 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212701035     link for HIV replication cycle myaaamin98 https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212701670 https://www.niaid.nih.gov/diseases-conditions/hiv-replication-cycle]]> 2017-12-04 03:55:25 UTC https://padlet.com/myaaamin98/9ihbdgpduxzj/wish/212701670