6.2.3 Cell-Mediated Immunity

• Cell-mediated immunity eliminates infected or cancerous cells without the use of antibodies
• What type of T-cell recognizes antigens presented by APCs and releases cytokines?

  Helper T-cells
• Cytotoxic T-cells induce apoptosis in target cells by releasing perforin and granzyme.
• Memory T-cells provide long-term immunity by responding to subsequent exposure to the same antigen
• Which two cytokines are critical for activating and modulating immune cells in cell-mediated immunity?

  Interleukin-2 and TNF-$\alpha$
• Match the type of T-cell with its function:

  Helper T-cells ↔️ Activate other immune cells

  Cytotoxic T-cells ↔️ Directly kill infected cells

  Memory T-cells ↔️ Provide long-term immunity
• Memory T-cells can include both helper and cytotoxic types.
• What type of immunity directly eliminates infected or cancerous cells without using antibodies?

  Cell-mediated immunity
• Helper T-cells are activated by antigens presented by APCs via MHC II
• Helper T-cells release cytokines to activate other immune cells.
• What is the function of cytotoxic T-cells in cell-mediated immunity?

  Eliminate infected cells
• Cell-mediated immunity involves Helper T-cells, Cytotoxic T-cells, and Memory T-cells.
• Memory T-cells provide long-term immunity by responding quickly to re-exposure to antigens.
• What are the three main types of T lymphocytes?

  Helper, Cytotoxic, Memory
• Helper T-cells release cytokines such as Interleukin-2 and TNF-$\alpha$ to activate immune cells.
• Cytotoxic T-cells induce apoptosis in infected or cancerous cells by releasing granzymes and perforin.
• Major types of antigen-presenting cells (APCs)

  1️⃣ Macrophages

  2️⃣ Dendritic cells

  3️⃣ B-cells
• Which type of APC phagocytoses pathogens and presents antigens via MHC II receptors?

  Macrophages
• Dendritic cells capture antigens in tissues and migrate to lymph nodes to activate T-cells.
• Cytotoxic T-cells are activated when they recognize antigens presented by APCs via MHC I receptors.
• Which cytokine released by Helper T-cells enhances the activation of cytotoxic T-cells?

  Interleukin-2
• Activated cytotoxic T-cells induce apoptosis in infected or cancerous cells.
• What type of cells present antigens to cytotoxic T cells via MHC I receptors?

  Antigen-presenting cells (APCs)
• Helper T-cells release cytokines like Interleukin-2
• What effect do cytotoxic T cells have on their target cells?

  Induce apoptosis
• Helper T-cells enhance cytotoxic T cell activation by releasing Interleukin-2.
• What type of antigens do helper T-cells recognize via MHC II receptors?

  Viral antigens
• Viral antigens displayed via $MHC I$ receptors are recognized by CTLs
• Cell-mediated immunity relies on antibodies to eliminate infected cells.

  False
• What role do helper T-cells play in cell-mediated immunity?

  Activate other immune cells
• Cytotoxic T cells induce apoptosis by releasing enzymes like perforin and granzyme
• What is the function of memory T-cells?

  Provide long-term immunity
• Match the T-cell type with its function:

  Helper T-cells ↔️ Activate other immune cells

  Cytotoxic T-cells ↔️ Eliminate infected cells

  Memory T-cells ↔️ Provide long-term immunity
• Interleukin-2 is a key cytokine that activates other immune cells.
• What type of antigens do cytotoxic T cells identify on infected cells?

  Viral or tumor antigens
• Memory T-cells respond to re-exposure by rapid activation and proliferation
• Match the T-cell type with its effect on target cells:

  Helper T-cells ↔️ Stimulate B-cells

  Cytotoxic T-cells ↔️ Cause cell lysis

  Memory T-cells ↔️ Fight subsequent infections
• How many main types of T lymphocytes are there?

  Three
• Helper T-cells release Interleukin-2 and TNF-$\alpha$ to activate other immune cells.
• Cytotoxic T cells induce apoptosis by releasing granzymes and perforin