Chapter 1- Introduction to Immune System Flashcards
define immunity
resistance to infectious disease
define immune system
collection of cells, tissues, and molecules that mediate resistance to infections
define immune response
coordinated reaction of the immune system to infectious microbes
define immunology
study of the immune system, including its responses to microbial pathogens and damaged tissues and its role in diseasE
What would be an implication if the role of the immune system “defense against infections” was compromised
deficient immunity results in increased susceptibility to infections
what does vaccination do
boosts immune defenses and protects against infections
what would be an implication if the role of the immune system “defense against tumors” was compromised
potential for immunotherapy of cancer
what would be an implication if the role of the immune system “injure cells and induce pathologic inflammation” was compromised
immune responses are the cause of allergic, autoimmune and other inflammatory diseases
what would be an implication if the role of the immune system “ability to recognize and respond to tissue grafts and newly introduced proteins” was compromised
immune responses are barrier to transplantation and gene therapy
what are the 2 divisions of the immune system
innate immunity and adaptive immunity
what are the components of innate immunity
-epithelial barriers
-mast cells
- phagocytes such as neutrophils, monocytes, macrophages
- dendritic cells
- NK cells and type 1 inferferons (IFN alpha/beta)
- complement system
what are the components of adaptive immunity
- B lymphocytes
- plasma cells
- antibodies
- T lymphocytes
- effector T cells
which part of the immune system works faster
innate immunity
how fast does the innate immune response take
within hours
what does the innate immune response recognized and what are they
- PAMPs: pathogen associated molecular patterns
- DAMPs: damage associated molecular patterns
genes encoding receptors that recognize PAMPS are present in the ______
germ line
describe PAMPs
- do not undergo somatic recombination or hypermutation
- no clonal expansion of cells of innate immune system in response to infection
- nonreactive to self
- no memory
which part of the immune system is antigen specific
adaptive immune system
how long does it take for the adaptive immune system to be effective
days to weeks
what does the adaptive immune system recognize
specific epitopes on specific proteins of specific pathogens
functional genes encoding antigen receptors are _____ present in the germ line
not
what are functional antigen receptor genes generated by
somatic recombination and mutation of germ line genes during maturation of B cells and T cells prior to exposure to any antigens
what does clonal selecction and proliferation of B and T lymphocytes depend on
exposure to specific antigens
is the adaptive immune system reactive to intself
no
which part of the immune system contributes to immunologic memory
adaptive
what are the types of adaptive immunity
humoral immunity and cell mediated immunity
describe the process of humoral immunity
-B lymphocytes respond to extracellular microbes
- antibody is secreted
- blocks infections and eliminates extracellular microbes
describe the process of cell mediated immunity
- phagocytosed microbes within macrophages
- helper T lymphocyte attaches to macrophage
- elimination of phagocytosed microbes
OR - intracellular microbes replicate within infected cell
- cytotoxic T lymphocyte kill infected cell
- kills infected cells and eliminates resevoirs of infection
what is the functional significance of specificity as a function of the adaptive immune system
ensures that distinct antigens elicit specific responses
what is the functional significance of clonal expansion as a function of the adaptive immune system
increases number of antigen specific lymphocytes from a small number of naive lymphocytes
describe the process of clonal selection
- lymphocyte clones with diverse recepors arise in lymphoid organs
- clones of mature lymphocytes specific for many antigens enter lymphoid tissues
-antigen specific clones are activated by antigens - antigen specific immune responses occur
what is the functional significance of memory as a function of the adaptive immune system
leads to enhanced responses to repeated exposures to the same antigens
what is the functional significance of specialization as a function of the adaptive immune system
generates responses that are optimal for defense against different types of microbes
what is the functional significance of contraction and homeostasis as a function of the adaptive immune system
allows immune system to respond to newly encountered antigens
what is the functional significance of nonreactivity to self as a function of the adaptive immune system
prevents injury to the host during responses to foreign antigens
what are the lymphocytes and what do they do
- B lymphocytes: mediators of humoral immunity
- T lymphocytes: mediators of cell mediated immunity
what are the antigen presenting cells and what are their functions
- dendritic cells: initiation of T cell responses
- macrophages: effector phase of cell mediated immunity
- follicular dendritic cells: display of antigens to B lymphocytes in humoral immune responses
what are the effector cells and what are their functions
- T lymphocytes: activation of phagocytes, killing infected cells
- macrophages: phagocytosis and killing of microbes
- granulocytes: killing microbes
what do B lymphocytes do
-neutralization of microbe
-phagocytosis
-complement activation
what do helper T lymphocytes do
- activation of macrophages
- inflammation
- activation of T and B lymphocytes
what do cytotoxic T lymphocytes do
kill infected cell
what do regulatory T lymphocytes do
suppression of immune response
where do B lymphocytes mature
bone marrow
where do T lymphocytes mature
thymus
where do B lymphocytes go once they mature
spleen and lymph nodes
where do T lymphocytes go once they mature
mucosal and cutaneous lymphoid tissue
what do B and T lymphocytes do after activation by antigen
migrate towards each other and meet at the edge of the follicle. the helper T cells will interact with and help B cells differentiate into antibody producing cells
what are the phases of the adaptive immune response
-clonal expansion
- differentiation
- elimination of antigens
- apoptosis
what is active immunity
- microbial anitgen by vaccine or infection enters host
- has specificity and memory
what is passive immunity
-administration of serum with antibodies to uninfected individual
- has specificity
- does not have. memory
