Ch. 13 innate and adaptive immunity Flashcards
immune response
Def- collective, coordinated response of the cells and molecules of the immune system
types=
+ Innate or nonspecific immunity: the natural resistance within which a person is born
+adaptive or specific immunity: the second line of defense, responding less rapidly than innate immunity but more effectively
principal cells of the immune system
-lymphocytes: cells that specifically recognize and respond to foreign antigens
-accessory cells: macrophages and dendritic cells
+functions as antigen-presenting cells by the processing of a complex antigen into epitopes required for the activation of lymphocyes
mediators of the immune system
- cytokines- soluble proteins secreted by cells of both the innate and adaptive immunity
- chemokines- cytokines that stimulate the migration and activation of immune and inflammatory cells
- colony-stimulating factors- stimulate the growth and differentiation of bone marrow progenitors of immune cells
innate immunity
-components
\+epithelial barriers
\+phagocytic cells
-neutrophils and macrophages
\+NK cells
\+plasma proteins
\+oposins, cytokines, and acute-phase proteins
-induction of inflammatory repsonse
soluble mediators of innate immunity
-oposins: facilitation of phagocytosis
+acute-phase reactants, lectin, complement proteins
+IgG and IgM with adaptive immunity
- cytokines: TNK, interleukinsm interferons, and chemokines
- acute-phase proteins: mannose-binding ligang and C-reactice protein
-complement system:
cytolysis, opsonization, chemotaxis, anaphylaxis
innate recognition systems
- pattern recognition receptors (PRRs)
- pathogen-associated molecular patterns(PAMPs)
- toll-like receptors (TLRs)
the complement system
- the complement system is found in the blood and is essential for the activity of antibodies
- activation of the complement system increase bacterial aggregation, which renders them more susceptible to phagocytosis
adaptive immunity
- able to recognize and react to a large number of microbes and nonmicrobial substances
- ability to distinguish among different, even closely related, microbes and molecules and to “remember” the pathogen by quickly producing a heightened immune response on sunsequent encounters
types of adaptive immune responses
-humoral immunity
+mediated by molecules in the blood
+the prinicipal defense against extracellular microbes and toxins
-cell-mediated immunity or cellular immunity
+mediated by specific T lymphocytes
+defends against intracellular microbes such as viruses
two types of immune cells
-regulatory cells
+assist in or orchestrating and controlling the immune response
+effector cells
- accomplish the final stages of the immune response with the elimination of the antigen
- activated T lymphocytes, mononuclear phagocytes, and other leukocytes function as effector cells in different immune responses
antigens and antibodies
-antigens: substances foreign to the bost that can stimulate an immune response
- antibodies: recognize antigens
- receptors on immune cells
- secreted proteins
types of antigens
- bacteria
- fungi
- viruses
- protozoa
- parasites
- nonmicrobial agents
properties of MHC molecules
-HLA antigens
+Class I: HLA-A, HLA-B, HLA-C
+class II: HLAR-DR, HLA- DP, HLA-DQ
-distribution
+Class I- virtually all nudeated cells
+class II: restricted to immune cells, antigen-presenting cells, B cells, and macrophages
-functions: \+class I: present processed antigen to cytotoxin CD 8+ T cells; restricted cytolysis to virus-infected cells, tumor cells, tranplanted cells \+class II: present processd antigenic fragments to CD 4+ T cells; necessary for effective interaction among immune cells
antigen presentation
- macrophages and dendritic cells process and present antigen peptides to CD4+ helper T cells
- capture antigens and then enable their recognition by T cells
- initiaion of adaptive immunity
Lymphocytes
- B cells: humoral immunity, Memory
- T cells: cell-mediated immunity, memory
Identifying factors by B lymphocytes
- presence of membrane immunoglobulin that functions as the antigens receptor
- class II MHC proteins
- Complement receptors
- specific CD molecules
Functions of the T lymphocytes
- activator or B and T cells
- controls intracellular viral infections
- rejects foreign bodies
- delayed hypersensitivity reaction
classes and functions of immunoglobulins
- IgG: displays antiviral, antitoxin, and antibacterial properties, responsible for protection newborn; activates complement and bind to macrophages
- IgA: predominant IG in body secretions; protects mucous membranes
- IgM: forms natural antibodies; prominent in early immune reponses, activites complement
- IgD: found on B lymphocytes, needed for maturation of B cells
- IgE: binds to mast cells and basophils; involved in parasitic infections, allergic and hypersenstivity
functions of the lymphoid organs
-central lymphoid organs (bone marrow and the thymus)
+provide the environemtn for immune cell production and maturation
-peripheral lymphoid organs
+function to trap and process antigen and promote its interaction with mature immune cells
immune response
- active immunity: specific protection induced following exposure to antigens
- passive immunity: specific protection induced through transfer of protective antibodies against an antigen
dev. of an immune response
-fetal dev. at 5-6 weeks
-secondary lymphoid organs wall developed at birth
-IgA and IgM shortly after birth
+reach adult levels by 1 year of age
the elderly immune system
-declining ability to adapt to environmental stresses
+decline in immune responsiveness
+decrease in the size of the thymus gland
+biological clock in T cells
+altered responses of the immune cells to antigen stimulation
