Innate recognition

• Define natural immunity

  Natural immunity is the body's first line of defence against pathogens and foreign substances. It is a non-specific immune response that provide immediate protection. It includes physical barrier such as the skin, mucous membrane and chemical barrier such as stomach acid and enzymes that help prevent infection.
• Define adaptive immunity

  Adaptive immunity is a specific immune response that develop over time as the body is exposed to pathogens. It involves the recognition of specific lymphocytes (T and B cells) and the productions of antibodies to target and eliminate pathogens. It provide long lasting protection and and the ability to mount a more-targeted response upon re-exposure to the same pathogen
• What are the different components of natural immune system

  Physical barrier, Chemical barrier, Cellular components, inflammatory response, complement system and cytokines
• Explain the function of physical barrier in natural immune system

  The skin and mucous membrane are body's first line of defence. The skin provides a protective barrier that prevents pathogens from entering the body, while mucous membranes in the respiratory, gastrointestinal, and urogenital tracts trap and expel pathogens.
• Explain the function of chemical barrier in natural immune system

  Stomach acid, enzymes, and antimicrobial peptides that help kill or inhibit the growth of pathogens. For example, stomach acid helps to destroy ingested pathogens, while antimicrobial peptides in bodily fluids can directly kill bacteria and other microbes.
• Explain the function of cellular components in natural immune system

  It include phagocytes (such as neutrophils, macrophages, and dendritic cells) that engulf and destroy pathogens through phagocytosis. Natural killer (NK) cells are another important cellular component that can recognize and kill infected or abnormal cells.
• Explain the function of inflammatory response in natural immune system

  Inflammatory is a key component that helps to localize and eliminate pathogens. When tissues are damaged or infected, immune cells release inflammatory mediators that increase blood flow to the area, leading to redness, swelling, heat, and pain.
• Explain the function of cytokines in natural immune system

  Cytokines are signaling molecules produced by immune cells that regulate the immune response. They can stimulate inflammation, activate immune cells, and coordinate the overall immune response to infection.
• Explain the function of complement system in natural immune sysytem

  It is a group of proteins that circulate in the blood and play a role in the innate immune response. Complement proteins can opsonize pathogens to enhance phagocytosis, trigger inflammation, and directly lyse pathogens.
• Describe the main components of adaptive immune system (specific/acquired immunity)

  Lymphocytes, antibodies, major histocompatibility complex (MHC), antigen presenting cells (APCs), memory cells and cytokines
• Explain the function of lymphocytes in adaptive immune system

  They are a type of white blood cell that plays a central role in the adaptive immune response. There are two main types of lymphocytes: B cells and T cells. B cells are responsible for producing antibodies, while T cells have various functions such as killing infected cells (cytotoxic T cells), helping B cells produce antibodies (helper T cells), and regulating the immune response (regulatory T cells).
• Explain the function of antibodies in adaptive immune system

  Antibodies, also known as immunoglobulins, are proteins produced by B cells in response to specific antigens. Antibodies can recognize and bind to antigens on pathogens, marking them for destruction by other immune cells or neutralizing harmful effects.
• Explain the function of major histocompatibility complex

  MHC molecules are cell surface proteins that present antigens to T cells, allowing the immune system to distinguish between self and non-self antigens. MHC class I molecules present antigens to cytotoxic T cells, while MHC class II molecules present antigens to helper T cells.
• Explain the function of memory cells in adaptive immune system

  After an initial exposure to a specific pathogen, memory B cells and memory T cells are generated. These memory cells can quickly recognize and mount a rapid and robust immune response upon re-exposure to the same pathogen, providing long-lasting immunity.
• Explain the function of antigen-presenting cells in adaptive immune system

  APCs, such as dendritic cells, macrophages, and B cells, play a crucial role in the adaptive immune response by capturing, processing, and presenting antigens to T cells. APCs activate T cells and initiate the adaptive immune response.
• Explain the function of cytokines in adaptive immune system

  Cytokines produced by various immune cells help regulate the adaptive immune response by coordinating the activities of different immune cells, promoting cell communication, and modulating the intensity and duration of the immune response.
• Describe the innate recognition receptors also known as pattern recognition receptors CD14 .

  • CD14 is a glycoprotein expressed on the surface of various immune cells, including monocytes, macrophages, and dendritic cells.
  • It acts as a co-receptor for Toll-like receptors (TLRs) and plays a role in the recognition of lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria.
  • CD14 facilitates the binding of LPS to TLR4, leading to the activation of downstream signaling pathways and the production of pro-inflammatory cytokines.