Innate Immunity Quiz

Innate Immunity

• Innate immunity is the routine protection present from birth
• Functions of chemical barriers in the innate immune system: diluting the number of pathogens and inhibiting bacterial growth
• Examples of antimicrobial substances involved in chemical barriers: lysozymes, peroxidase enzymes, and defensins
• Hormones are not an example of antimicrobial substances involved in chemical barriers
• Normal microbiota in innate immunity: providing a competitive exclusion of pathogens and modulating the immune system

Blood Cells

• Hematopoietic stem cells (HSC) are produced in the bone marrow
• Red blood cells are responsible for carrying oxygen throughout the body
• Neutrophils are a type of white blood cell that engulfs and destroys bacteria

Immune System

• Mast cells in the immune system: produce histamines
• Limitation of Koch's Postulates: some organisms cannot be grown in laboratory medium
• Molecular Koch's Postulates rely on molecular techniques to study a microbe's virulence factors

Infection Process

• Steps in starting an infection in a host: adherence, colonization, invasion, and avoiding host defenses
• Structure of bacteria involved in adherence to host cells: fimbriae
• Adhesins bind to host cell receptors in the process of adherence
• Bacteria grow in colonization by forming biofilms
• Methods bacteria use to avoid host defenses: rapid pili turnover, antigenic variations, and binding to host cell receptors
• Easiest barrier for pathogens to penetrate: mucous membranes

Pathogen Avoidance

• Ways bacteria breach anatomical barriers: directed uptake by cells
• Effector proteins delivered by the Type III secretion system affect host cells by altering the host cell's cytoskeleton structure
• Phases of avoiding destruction by phagocytes: preventing encounters, avoiding recognition and attachment, surviving within phagocytes
• Function of C5a peptidase in preventing encounters with phagocytes: degrades chemoattractant C5a
• Function of membrane-damaging toxins in avoiding destruction by phagocytes: killing phagocytes and other cells
• Function of capsules in avoiding recognition and attachment: interfering with opsonization

Pathogen Examples

• Pathogen that produces a molecule that forms pores in the membrane to escape from the phagosome: Listeria monocytogenes
• Function of IgA protease: breaks down IgA antibodies