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Hiv Pre by pooja


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hiv presentation by pooja

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Hiv Pre by pooja

  1. 1. HIV/AIDS Presented by: Pooja Kanhya Lal
  2. 2. <ul><li>HIV stands for Human Immunodeficiency Virus. Like all viruses, HIV cannot grow or reproduce on its own. In order to make new copies of itself it must infect the cells of a living organism. </li></ul><ul><li>HIV belongs to a special class of viruses called retroviruses. </li></ul><ul><li>HIV is a virus that takes over certain immune system cells to make many copies of itself.  HIV causes slow but constant damage to the immune system, a disease called AIDS. </li></ul>WHAT IS HIV?
  3. 3. <ul><li>Each HIV virion (viral particle) is a small sphere composed of several layers. </li></ul><ul><li>The external layer is a membrane coat, or envelope, obtained from the host cell in which the particle was made. </li></ul><ul><li>Underneath this membrane lies a shell made from proteins, called a nucleocapsid. </li></ul><ul><li>Inside the protein shell are two copies of the virion's RNA genome and three kinds of proteins, which are used by the virion to establish itself once inside the cell that it infects. </li></ul><ul><li>Two proteins, called gp120 and gp41, enable the virion to recognize the type of cell to enter. These proteins project from the HIV membrane coat. </li></ul>STRUCTURE OF HIV
  4. 4. <ul><li>Gp120 binds to two specific proteins found on the target cell's surface (these target-cell proteins are called receptors). </li></ul><ul><li>The first receptor, CD4, is found on immune system cells known as CD4 T cells, and the second is the co-receptor. </li></ul><ul><li>The co-receptor can be one of many different proteins, depending on the cell type. The two most common are CXCR4 and CCR5. </li></ul><ul><li>Once gp120 has bound to both the CD4 receptor and co-receptor, the gp41 protein fuses HIV's membrane envelope with the cellular membrane, injecting the virus into the target cell. </li></ul><ul><li>Once in the cytoplasm, the viral protein shell opens up and releases the viral proteins—a reverse transcriptase, a viral integrase, and a protease—along with the viral RNA strands. </li></ul>ENTRY IN THE CELL
  5. 6. <ul><li>Once inside the cell, the HIV enzyme reverse transciptase converts the viral RNA into DNA, which is compatible with human genetic material. </li></ul><ul><li>This DNA is transported to the cell's nucleus, where it is spliced into the human DNA by the HIV enzyme integrase. Once integrated, the HIV DNA is known as provirus. </li></ul><ul><li>HIV provirus may lie dormant within a cell for a long time. </li></ul><ul><li>But when the cell becomes activated, it treats HIV genes in much the same way as human genes. </li></ul><ul><li>First it converts them into messenger RNA (using human enzymes). </li></ul><ul><li>Then the messenger RNA is transported outside the nucleus, and is used as a blueprint for producing new HIV proteins and enzymes. </li></ul><ul><li>Among the strands of messenger RNA produced by the cell are complete copies of HIV genetic material. </li></ul>HIV LIFE CYCLE
  6. 7. <ul><li>These gather together with newly made HIV proteins and enzymes to form new viral particles, which are then released from the cell. </li></ul><ul><li>The enzyme protease plays a vital role at this stage of the HIV life cycle by chopping up long strands of protein into smaller pieces, which are used to construct mature viral cores. </li></ul><ul><li>The newly matured HIV particles are ready to infect another cell and begin the replication process all over again. In this way the virus quickly spreads through the human body. And once a person is infected, they can pass HIV on to others in their bodily fluids. </li></ul>
  7. 8. <ul><li>Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, or breast milk. </li></ul><ul><li>Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells. </li></ul><ul><li>The four major routes of transmission are: </li></ul><ul><li>Unprotected sexual intercourse </li></ul><ul><li>Contaminated needles </li></ul><ul><li>Transmission from an infected mother to her baby at birth or while breast feeding </li></ul>TRANSMISSION OF HIV
  8. 9. <ul><li>HIV initially causes an acute illness with nonspecific or flu-like symptoms such as fatigue, headache, fever, and enlarged lymph nodes. Some people will not experience any noticeable symptoms. </li></ul><ul><li>Eventually, the affected person’s immune system is compromised to the extent that they begin having symptoms such as weight loss, sweating, recurrent yeast infections, fever, herpes infections, rashes, and memory loss or difficulty concentrating. </li></ul><ul><li>In children who are infected with HIV at or before birth, symptoms may emerge within a couple of years. They may have delayed development and be frequently ill </li></ul>SYMPTOMS OF HIV INFECTION
  9. 10. <ul><li>Today there is no specific cure for HIV, but there are some drugs that inhibit the activities of vital parts of HIV, which include: </li></ul><ul><li>Drugs meant to knock out HIV target the activities of two HIV proteins, the reverse transcriptase and the protease. </li></ul><ul><li>Drugs called protease inhibitors prevent the viral protease from trimming down the large proteins made late during infection. Without those proteins, the viral shell cannot be assembled. In addition, the proteins that reproduce HIV's genetic information, the reverse transcriptase and the integrase, are not functional. </li></ul><ul><li>Drugs that inhibit the reverse transcriptase prevent it from copying the RNA into DNA. These drugs work early in the life cycle of HIV. </li></ul>CURE FOR HIV/AIDS
  10. 12. <ul><li>Methods should be used to avoid transmission of bodily fluids during sexual intercourse with an infected partner. </li></ul><ul><li>Blood should be checked before transfusion for the presence of HIV. </li></ul><ul><li>Needles and syringes used should be sterilized. </li></ul><ul><li>An infected mother should avoid feeding her child via breast. </li></ul><ul><li>Steps should be taken by several AIDS organization to create awareness in people. </li></ul>PREVENTION
  11. 13. Thanks for your time..