HIV and Immune Response Overview
95 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary consequence of HIV infection on CD4 T cells?

  • Increased production of cytokines
  • Promotion of B cell activation
  • Enhanced cell-mediated immunity
  • Depletion of CD4 T cells (correct)

    • Which cells first encounter HIV during genital infection?

  • Dendritic cells (correct)
  • CD8 T cells
  • Epithelial cells
  • B cells

    • What is the role of CD8 T cells in the immune response to HIV?

  • They enhance the production of antibodies
  • They activate CD4 T cells
  • They induce cytokine release from macrophages
  • They control HIV infection (correct)

    • What cytokine is primarily responsible for driving CD4 T cells towards the Th1 subset?

    <p>Interleukin-12 (IL-12)</p> Signup and view all the answers

    How do CD8 T cells contribute to fighting intracellular pathogens?

    <p>By releasing perforin and granzymes</p> Signup and view all the answers

    Which cytokines are characteristic of the Th1 profile secreted by differentiated CD4 T cells?

    <p>Interleukin-2 (IL-2) and Interferon-gamma (IFN-γ)</p> Signup and view all the answers

    In which direction does HIV cause a shift in CD4 T cell responses?

    <p>From Th1 to Th2</p> Signup and view all the answers

    What is the function of CD4 T cells in the immune response?

    <p>Enhance the activity of other immune cells</p> Signup and view all the answers

    Which type of cells does HIV preferentially infect and destroy?

    <p>CD4+ T lymphocytes</p> Signup and view all the answers

    What is the primary mode of transmission for HIV?

    <p>Sexual contact</p> Signup and view all the answers

    Which cytokine is crucial for maintaining the viability of T cells?

    <p>IL-2</p> Signup and view all the answers

    What is the CD4 T cell count threshold that defines AIDS?

    <p>200/mm3</p> Signup and view all the answers

    Which strain of HIV is more prevalent worldwide?

    <p>HIV-1</p> Signup and view all the answers

    What defines HIV as a member of the retrovirus group?

    <p>It contains two identical copies of RNA.</p> Signup and view all the answers

    Which protein is NOT associated with the HIV virus envelope?

    <p>gp150</p> Signup and view all the answers

    Which immune cytokine is primarily responsible for enhancing the effector functions of immune cells?

    <p>IFN-γ</p> Signup and view all the answers

    Which gene encodes the internal 'core' proteins, including the p24 antigen?

    <p>gag</p> Signup and view all the answers

    What role does the reverse transcriptase enzyme play in HIV replication?

    <p>Synthesizes DNA from viral RNA</p> Signup and view all the answers

    Which proteins are required for the entry of HIV into CD4-positive cells?

    <p>CXCR4 and CCR5</p> Signup and view all the answers

    What defines T-cell-tropic strains of HIV?

    <p>They bind specifically to CXCR4</p> Signup and view all the answers

    What is typically the reason for false-negative antibody tests during the first month after HIV infection?

    <p>Insufficient antibody being produced early in the infection</p> Signup and view all the answers

    Which viral protein is cleaved to form the surface glycoproteins gp120 and gp41?

    <p>env</p> Signup and view all the answers

    What method can be employed to detect the presence of HIV during acute infection?

    <p>Plasma HIV RNA assay</p> Signup and view all the answers

    What does the HIV antigen/antibody 'Combo' test specifically detect?

    <p>p24 antigen and antibodies to both HIV-1 and HIV-2</p> Signup and view all the answers

    During HIV replication, what is the function of the viral protease?

    <p>Cleaves precursor polyproteins</p> Signup and view all the answers

    What happens after the uncoating of the HIV virion?

    <p>The genome RNA is transcribed to double-stranded DNA</p> Signup and view all the answers

    At what CD4 T cell count is an individual considered to have AIDS?

    <p>Below 200 cells/mm3</p> Signup and view all the answers

    Which of the following treatments is considered the most effective for managing HIV?

    <p>Antiretroviral therapy (ART)</p> Signup and view all the answers

    What activity does the integrase enzyme perform in the lifecycle of HIV?

    <p>Integrates viral DNA into the host cell DNA</p> Signup and view all the answers

    What was the initial recommendation by the WHO in 2013 for initiating ART treatment?

    <p>When CD4 T cell counts fall below 500 cells/mm3</p> Signup and view all the answers

    What is the significance of preventing opportunistic infections in HIV patients?

    <p>It aids in the overall management and health of HIV-infected individuals</p> Signup and view all the answers

    How many individuals worldwide were reported to have HIV or AIDS as of 2015?

    <p>37 million</p> Signup and view all the answers

    What is the primary role of IFN-γ in the immune response?

    <p>It induces IL-12 production to amplify the Th1 response.</p> Signup and view all the answers

    Which cytokine produced by activated APCs leads to the differentiation of CD4 T cells into Th2 cells?

    <p>IL-4</p> Signup and view all the answers

    What is the effect of the Th2 response in individuals infected with HIV?

    <p>Suppression of CD4 T cells and increase in intracellular infections.</p> Signup and view all the answers

    Which cytokine is primarily responsible for attracting neutrophils to sites of bacterial infection?

    <p>IL-17</p> Signup and view all the answers

    In the context of HIV infection, what shift occurs in the immune response?

    <p>From Th1 to Th2 response.</p> Signup and view all the answers

    Which of the following cell types primarily produces CCL2?

    <p>Macrophages and monocytes</p> Signup and view all the answers

    What effect do Th2 cytokines have on B cells?

    <p>They promote B-cell differentiation and class switching.</p> Signup and view all the answers

    What is a consequence of the Th2 response in the context of HIV?

    <p>Increased susceptibility to opportunistic infections.</p> Signup and view all the answers

    What is the primary consequence of CD8 T cells losing their ability to control mutant strains of HIV?

    <p>Development of AIDS</p> Signup and view all the answers

    During the acute stage of HIV infection, which of the following symptoms is typically observed?

    <p>Generalized lymphadenopathy</p> Signup and view all the answers

    What happens to CD4 helper T cells during the progression of HIV infection?

    <p>They die, leading to reduced cytokine support</p> Signup and view all the answers

    What is a characteristic finding during the acute stage of HIV infection regarding CD4 cell count?

    <p>CD4 cell count is usually normal</p> Signup and view all the answers

    What indicates that a person might still be infected with HIV despite a negative antibody test?

    <p>Detection of viral RNA through PCR</p> Signup and view all the answers

    What is often observed along with a high level of viremia during the acute stage of HIV infection?

    <p>Rise in CD8-positive T cells</p> Signup and view all the answers

    Which cytokines are mentioned as being critical for activating and maintaining cytotoxic T cells?

    <p>IL-2 and IFN-γ</p> Signup and view all the answers

    What typically occurs two weeks after the acute stage of HIV infection begins?

    <p>Spontaneous resolution of acute symptoms</p> Signup and view all the answers

    What leads to the ultimate failure of CD8 T cells in controlling HIV infection?

    <p>The mutation of gp120 in HIV</p> Signup and view all the answers

    Which characteristic is typical during the acute stage of HIV infection?

    <p>Presence of maculopapular rash</p> Signup and view all the answers

    What is the consequence of decreased Th1 CD4 helper T cells during HIV infection?

    <p>Insufficient lymphokines to activate cytotoxic T cells</p> Signup and view all the answers

    What symptom is NOT typically observed during the acute stage of HIV infection?

    <p>A significant increase in CD4 count</p> Signup and view all the answers

    What is the typical time frame for antibodies to HIV to become detectable after infection?

    <p>10 to 14 days</p> Signup and view all the answers

    What does a negative antibody test during the early phase of HIV infection imply?

    <p>The infection is undetectable at the antibody level</p> Signup and view all the answers

    Which of the following is NOT a feature of the acute stage of HIV infection?

    <p>Rapid loss of Th1 CD4 T cells</p> Signup and view all the answers

    During the acute stage of HIV infection, what is the transmission risk?

    <p>Increased due to high-level viremia</p> Signup and view all the answers

    What is the clinical implication of having CD4 T cell counts below 200/mm3?

    <p>Development of AIDS</p> Signup and view all the answers

    What primarily distinguishes HIV-1 from HIV-2 in terms of geographical prevalence?

    <p>HIV-1 is found worldwide, while HIV-2 is mainly in West Africa</p> Signup and view all the answers

    What is the primary function of the pol gene in the HIV genome?

    <p>Encodes enzymes such as reverse transcriptase and integrase</p> Signup and view all the answers

    Which step is involved in the initial entry of HIV into host cells?

    <p>Binding of gp120 to CD4 receptors on host cells</p> Signup and view all the answers

    Which of the following is NOT a consequence of decreased levels of IL-2, IFN-γ, and IL-17 in individuals with AIDS?

    <p>Normal development of CD4 T cells</p> Signup and view all the answers

    How does HIV primarily replicate within the host cells?

    <p>By reverse transcription of RNA to cDNA</p> Signup and view all the answers

    HIV strains that bind primarily to the chemokine receptor CCR5 are classified as what type of strains?

    <p>Macrophage-tropic strains</p> Signup and view all the answers

    Which type of viruses does HIV belong to, and what characteristic do they share?

    <p>Retroviruses; long incubation periods</p> Signup and view all the answers

    What is a result of the protease enzyme activity during HIV replication?

    <p>Cleavage of precursor polyproteins into functional proteins</p> Signup and view all the answers

    Which glycoprotein is cleaved to form gp120 and gp41?

    <p>env</p> Signup and view all the answers

    Which immune response is primarily affected by HIV infection due to a decrease in specific cytokines?

    <p>Th1-mediated adaptive immunity</p> Signup and view all the answers

    What role do the proteins gp120 and gp41 play in the lifecycle of HIV?

    <p>They facilitate the entry of HIV into CD4-positive cells</p> Signup and view all the answers

    After HIV uncoating, what process converts the viral RNA into double-stranded DNA?

    <p>Reverse transcription by RNA-dependent DNA polymerase</p> Signup and view all the answers

    What major consequence does HIV infection have on the immune system's CD4 T lymphocytes?

    <p>Destruction and reduction in numbers</p> Signup and view all the answers

    What is the role of the virion gp41 protein in the HIV lifecycle?

    <p>Mediates fusion of the viral envelope with the host cell membrane</p> Signup and view all the answers

    What is the significance of the structural protein p24 in HIV diagnosis?

    <p>It serves as a marker in serologic tests for HIV infection.</p> Signup and view all the answers

    What is the most characteristic manifestation of AIDS?

    <p>Pneumonia caused by Pneumocystis jiroveci</p> Signup and view all the answers

    Which of the following is a common viral opportunistic infection associated with AIDS?

    <p>Herpes zoster</p> Signup and view all the answers

    What is the primary method used for the definitive diagnosis of HIV infection?

    <p>Western blot analysis</p> Signup and view all the answers

    Which test can detect HIV DNA within infected cells?

    <p>PCR test</p> Signup and view all the answers

    Which opportunistic infection is caused by Candida albicans?

    <p>Thrush</p> Signup and view all the answers

    What common symptom can result from HIV infection affecting the brain?

    <p>Neuropathy</p> Signup and view all the answers

    What is the typical timeframe for results from an OraQuick rapid HIV test?

    <p>20 minutes</p> Signup and view all the answers

    Which method is utilized to confirm positive HIV antibody test results?

    <p>Western blot test</p> Signup and view all the answers

    What type of immune response is primarily affected by the depletion of CD4 T cells during HIV infection?

    <p>Cell-mediated immunity</p> Signup and view all the answers

    Which cytokine is responsible for causing CD4 T cells to differentiate into the Th1 subset?

    <p>Interleukin-12 (IL-12)</p> Signup and view all the answers

    How do CD8 T cells contribute to the immune response against viral infections?

    <p>By killing infected host cells</p> Signup and view all the answers

    What is a characteristic function of CD4 T cells within the immune system?

    <p>Enhancing macrophage and neutrophil functions</p> Signup and view all the answers

    What does the shift from Th1 to Th2 response in HIV-infected patients lead to?

    <p>Enhanced antibody production and immune suppression</p> Signup and view all the answers

    What is the role of the cytokines IL-2 and IFN-γ produced by Th1 cells?

    <p>Promoting proliferation of CD4 and CD8 T cells</p> Signup and view all the answers

    What happens to CD4 T cells during the early days of HIV infection after initial exposure?

    <p>They become infected and begin to decline</p> Signup and view all the answers

    Which cells are primarily the first to encounter HIV during genital tract infection?

    <p>Dendritic cells</p> Signup and view all the answers

    What is the primary reason false-negative antibody tests occur within the first month of HIV infection?

    <p>Insufficient antibody is produced early in infection.</p> Signup and view all the answers

    Which test is recommended for early diagnosis of HIV infection due to its ability to detect p24 antigen?

    <p>HIV antigen/antibody 'Combo' test</p> Signup and view all the answers

    What is the current recommendation from the WHO regarding when to start antiretroviral therapy (ART)?

    <p>Immediately, regardless of CD4 count</p> Signup and view all the answers

    Which of the following is considered a key factor in treating HIV-infected patients?

    <p>Prevention of opportunistic infections</p> Signup and view all the answers

    What is the average time frame for seroconversion following an HIV infection?

    <p>10 to 14 days</p> Signup and view all the answers

    Which test is used to detect the presence of HIV during acute infection due to high viremia?

    <p>Viral load assay</p> Signup and view all the answers

    What is the significance of CD4 T cell counts in HIV-infected individuals?

    <p>They help determine the stage of HIV infection.</p> Signup and view all the answers

    More Like This

    HIV-1 Fusion Receptors Quiz
    3 questions

    HIV-1 Fusion Receptors Quiz

    AmicableChalcedony1640 avatar
    AmicableChalcedony1640
    HIV Virus and CD4 Cell Interaction
    10 questions

    HIV Virus and CD4 Cell Interaction

    UnwaveringParody avatar
    UnwaveringParody
    Chest Manifestations in HIV Patients
    5 questions

    Chest Manifestations in HIV Patients

    GratefulPink1719 avatar
    GratefulPink1719
    HIV and AIDS Overview Quiz
    232 questions

    HIV and AIDS Overview Quiz

    RegalElder7207 avatar
    RegalElder7207
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser