Immune System Flashcards
Intrinsict mechanisms that are poised to react immediately and thus constitute the first line of defense?
Innate Immunity
Cells that recognize and destroy severely stressed or abnormal cells , such as virus-infected cells and tumor cells.
Natural killer Cells
Phenomenon known to express CD 16 that confers on NK cells the ability to lyse IgG coated target cells.
ADDC ( Antibody Dependent Cellular Cytotoxicity)
Consists of mechanisms that are stimulated by exposure to microbes. Mediated by lymphocytes and their products including antibodies.
Adaptive Immunity
Protects against extracellular microbes and their toxins, mediated by B lymphocytes and secreted antibodies.
Humoral Immunity
Responsible for defense against extracellular microbes, mediated by T lymphocytes.
Cell Mediated Immunity
Mature lymphocytes that have not encountered the antigen for which they are specific.
Naive lymphocytes ( Immunologically Inexperienced)
Perform the function of eliminating microbes.
Effector cells
Live in a state of heightened awareness and are able to react rapidly and strongly to combat the microbe in case it returns.
Memory Cells
True or False
60% of Mature T cells are CD4+
True
60% are CD4+
30% are CD 8+
Stimulate B lymphocytes to make antibodies and activate other leukocytes to destroy microbes.
Helper T lymphocytes or CD4
Kill infected cells and recognize cell-bound antigens only in association with class I MHC molecules.
Cytotoxic T lymphocytes (CTLs)
Limit immune responses and prevent reactions against self-antigens.
Regulatory T lymphocytes
Only cells in the body capable of producing antibody molecules.
B lymphocytes
Most important antigen-presenting cells for initiating T-cell responses against protein antigens.
Dendritic cells
Immature dendritic cells within the epidermis.
Langerhans cells
Present in the germinal centers of lymphoid follicles in the spleen and lymph nodes and plays a role in humoral responses by presenting antigens to B cells in the germinal center.
FDC ( Follicular Dendritic Cells)
Functions for phagocytosis and antigen presentation.
Macrophages
Destroy irreversibly stressed and abnormal cells , such as virus infected cells and tumor cells.
NK cells (CD26, CD56)
Where does T cells develop?
Thymus
Where do B lymphocytes mature?
Bone marrow
Secondary peripheral lymphoid organs. (4)
- Lymph nodes
- Spleen
- Mucosal Lymphoid Tissues (Gastrointestinal & Respiratory tracts)
- Cutaneous Lymphoid Tissues ( Epithelia of Skin)
What part of the spleen T lymphocytes resides?
Periarteriolar lymphoid sheaths surrounding small arterioles
What part of the spleen B lymphocytes resides?
Follicles ( Splenic White Pulp)
Class I MHC ( Major Histocompatibility Complex) are recognized by what T cells?
CD8+ T lymphocytes
Class II MHC ( Major Histocompatibility Complex) are recognized by what T cells?
CD4+ T cells
Cells that secrete the cytokine IFN-delta, which is a potent macrophage activator.
TH 1 cells
Produce IL-4 that stimulates B cells to differentiate into IgE secreting plasma cells.
TH2 cells
Produce IL-5 which activates eosinophils.
TH2 Cells
Secretes IL-17 that recruits neutrophils and monocytes.
TH17 cells
Polysaccharides and lipids stimulate secretion of what antibody?
IgM
What antibody coats / opsonize microbes and target them for phagocytosis?
IgG
Antibodies that activates the Classical pathway of Complement system? (2)
IgG & IgM
Secreted from mucosal epithelia and neutralizes microbes in the lumens of respiratory and gastrointestinal tracts.
IgA
Antibody that cooperates to eosinophils to kill parasites, mainly by release of eosinophil granule contents that are toxic to the worms.
IgE
Any substance that prompts your body to trigger an immune response against it.
Antigen
Eg. Allergens, bacteria, virus..
Are Y-shaped proteins produced upon detection of antigens.
Antibody
In type I hypersensitivity/ Immediate hypersensitivity, injuries are caused by what antibodies? (3)
TH2 cells
IgE antibodies
Mast cells
Can be detected in the sputum of patients with asthma.
Charcot-Leyden Crystals
Type I hypersensitivity/ Immediate Hypersensitivity Reactions. (6)
Skin allergies
Hives
Allergic rhinitis
Hay fever
Bronchial asthma
Systemic anaphylaxis
Antibodies Responsible for Type II hypersensitivity/ Antibody-mediated Disorders?
IgG & IgM
Interfere with normal functions or injure cells by promoting phagocytosis or lysis and inducing inflammation.
Type II hypersensitivity/ Antibody-mediated Disorders. (4)
- Transfusion reactions
- Hemolytic Disease of the newborn ( Erythroblastosis fetalis)
- Myasthenia gravis (Ach receptors)
- Grave’s disease (TSH Receptor)
Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction. (3)
- Arthus reaction
- Acute serum sickness ( Administration of large amounts of foreign serum)
- SLE
Antibodies responsible for Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction.
IgG and IgM
Same in Type II they induce inflammation.
(+) Fibrinoid necrosis
Antibodies responsible for Cell- mediated immune disorders / Type IV hypersensitivity reactions.
T lymphocytes
Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction. (2)
- Delayed-type hypersensitivity in tuberculin reaction.
- CD8 + T cell Mediated Cytotoxicity - involved in perforins and granzymes leading to apoptosis of the target cell.
Classical , Alternative and Lectin Pathway meets at ?
C3
What are the two types of C3 convertase?
C4b2a & C3bBb
Complements that cause inflammation?
C3a and C5a
( Aenflammation)
Complement that functions for opsonization?
C3b
(Bidabida )
Complements for MAC ( Membrane attack complex) ? (5)
C5b ( bidabida) combines with C6-C9 to form the MAC and induce cellular lysis to infected cells.
What are the 2 types of C5 convertase?
C4b2aC3b & C3bBbC3b
What complement pathway is blocked by Meningococcal disease? (2)
Alternative Pathway & Lectin Pathway
What conplement pathway is blocked by Neisseria infection?
MAC (C5-C9)
What complement pathway is blocked by Bacterial infections ( pneumococcus , h. influenzae) ?
Classical Pathway
