Intro to Immunology Flashcards
Distinguish the roles of innate and adaptive immunity, including humoral (antibody-mediated) and cell-mediated immune responses
Innate:
- rapid, initial defense
- blocks entry of microbes into tissue
- rapidly eliminates microbes that enter
Adaptive:
- develops more slowly than innate
- more specific and effective
Humoral:
- B lymphocytes respond and release antibodies
- antibodies are the effector molecules
- block infections and eliminate extracellular
microbes
Cell-mediated:
- Helper T cells or Cytotoxic T cells
- eliminate intracellular or phagocytized microbes
Define antigens and their relationship to immune recognition
- molecules recognized by the adaptive immune system
- any chemical structure, typically proteins, glycoproteins, and polysaccharides
- recognized by B and T cells
Define epitopes and their relationship to immune recognition
- sites within antigens in which antigen receptors bind
- can can conformational (discontinuos) or linear (continuous)
- macromelcular agents can be recognized by different antigen receptors
Explain key properties of adaptive immune responses: specificity
ensures immune responses are limited to microbial pathogens
Explain key properties of adaptive immune responses: diversity
enables immune system to respond to a large variety of antigens
Explain key properties of adaptive immune resposnes: memory
leads to enhanced responses to repeated exposures of the same antigen
Explain key properties of adaptive immune responses: clonal expansion
increases number of antigen-specific lymphocytes from small number of naiive lymphocytes
Explain key properties of adaptive immune responses: specialization
generate responses optimal for defense against different microbes
Explain key properties of adaptive immune responses: contraction and homeostasis
allows immune system to respond to newly encountered antigens
Explain key properties of adaptive immune responses: nonreactivity to self
prevents injury to the host during immune response
Describe the general functions of antigen-presenting cells
- dendritic cells (initiate T cell response), macrophages (mediated cell immunity), B cells, follicular dendritic cells (humoral immune response)
- capture antigens to display on cell surface for lymphocytes
Describe the general functions of T and B lymphocytes
Helper or Cytotoxic T: cell-mediated immunity
-Helper: release cytokines to activate macrophages, cause inflammation, activate B cells
-Cytotoxic: kill the cell
B: humoral immunity
-secrete antibodies to bind to antigens on extracellular microbes
Describe the general functions of natural killer cells
kill infected cells
Explain the general roles of generative/primary lymphoid organs in the immune system
- sites of lymphocyte cell development
- bone marrow and thymus
Explain the general roles of peripheral lymphoid organs/tissues in the immune system
- site of lymphocyte activation by antigen
- spleen (filter for antigens in blood)
- lymph nodes (filter for antigens in lymph)
- mucosal and cutaneous lymphoid tissues (for immune responses that breach the skin)
Explain the general roles of lymphatics in the immune system
- system of vessels that collect lymph
- interspersed with lymph nodes
- fats, fluids, and foreign particles make up lymph
Describe the basic concept and significance of lymphocyte recirculation and migration into tissues
- lymphocytes recirculate in lymph
- lymphocytes exit lymphoid tissue via lymphatics, move through blood, migrate to sites of infection, fight
Describe the phases and key players in an immune response to a microbe including the innate and adaptive response
1) Innate immunity
2) Antigen recognition - antigen-presenting cell + Naive B/T cell (then clonal expansion)
3) lymphocyte activation - differentation antibody-producing cell & effector T-lymphocyte
4) antigen elimination - humoral and cell-mediated immunity
5) contraction/homeostasis - apoptosis
6) memory - surviving memory cells
Explain the general concept of immune-mediated damage and their relationship to disease
-hypersensitivity (excessive immune response) or autoimmunity (attack the host)
Explain the general concept of immunodeficiency and their relationship to disease
-compromised immune system that leads to increase in the number of infections
What is passive immunity?
- a form of adaptive immunity
- recieve antibodies from mother (breastfeeding) or through plasma of someone else who has antibodies
What are PAMPs?
- Pathogen-Associated Molecular Patterns
- structures shared by various classes of microbes
- NOT present in noral mammalian cells
- recognized by pattern recognition receptors (PRR)
What are DAMPs?
- Danger-Associated Molecular Patterns
- molecules released from damaged or necrotic mammalian cells
- not released by healthy cells
- recognized by certain receptors
What is an antibody/immunoglobin?
- membrane-bound or secreted protein
- membrane bound: antigen receptor for B cells
- secreted: effector molecules of humoral immunity
What are cytokines?
-proteins made and secreted from a variety of cells that mediate inflammatory responses and communication in the immune system
