Introduction to Immunology. 1&2 Flashcards
The body’s defense system can be divided into
- Natural/Innate/Non-specific
E.g unbroken skin, Any body’s secretion, Basic proteins like: lysosome, lysozyme, lysoferrin e.t.c, cells: PMNs, macrophages, NK cells - Adaptive/Acuired/specific:
Cellular immunity- T-cells
Humoral- B-cells
Which immunity is capable of recognizing antigens
Adaptive
Acute inflammation is a component of
Innate
Defense against Intracellular microbes by adaptive immunity is specifically by
Cell mediated(T lymphocytes)
Defense against extracellular microbes by adaptive immunity is specifically by
Humoral(B lymphocytes)
Antibodies are secreted by
B cells
The three ways in which antibodies work
Neutralization
Opsonization- interaction with phagocytes
Complement activation-direct lysis
What are antibodies
Cell surface Receptors(immunoglobulin molecules) of B cells(Derived and matured in Bone marrow )
Developement of T lymphocyte
Arise in bone marrow but mature’s in Thymus
Organs of immune system
Bone marrow
Thymus
Spleen
MALT
Primary lymphoid organs
Bone marrow
Thymus
Secondary lymphoid organ
Spleen
Peyer’s patches
Tonsils and adenoids
Collections in lungs,git,liver
Percentage of T-lymphocytes making up blood lymphocytes
60-70%
Percentages of CD4+ and CD8+ respectively.
60%
30%
Master regulators
CD4+
What areas in the LN and spleen is T lymphocytes found
Paracortical
Periarterial
2 signals for activation of Tcells
- MHC-bound antigen with TCR
2. CD28 molecules on T cells with BT-1, BT-2 expressed on APC
Division of CD4
TH1- IL2, interferon gamma-yIFN(for delayed hypersensitivity), macrophage activation, synthesis of igG2B
TH2- secretes IL4,IL5 which aids type 1 hypersensitivity rxn
CD4 binds to what MHC on antigens
MHCII
CD8 binds to what MHC on APC
MHC I
B-lymphocytes constitute how many percentage of lymphocytes
10-20%
Macrophages plays both -&- function of immune response
Induction and effector
What presents antigen to immunocompetent T-cells
Macrophages
What plays the effector role in delayed hypersensitivity rxn
Macrophages
What plays the effector role in humoral immunity
Macrophages
Are dendritic cells phagocytes
No
Dentritic cells contains what MHC class.
II
Function of dendritic cells
They present Ag to CD4+
Examples of dendritic cells
Langerhan cells
Follicular dendritic cells
Cytokines that mediates natural immunity
IL-1, TNF, IL-6
Cytokines that regulates lymphocyte growth, activation and differentiation
IL-2,4,5,TGF-Beta,IL-15
Cytokines that activates inflammatory cells
IFN-y, TNF-a, , TNF-F
Chemokines(cytokines that affects leukocyte movement)
IL-8
What are the properties of cytokines
- They are produced by several different cells
- Pleiotropic effect- can act on many cell type. e.g IL-2 can act on both B cells and NK to cause growth and differentiation
Mention the 3 ways cytokines induce their effect
Autocrine
Paracrine
Endocrine
Major Histocompatibility antigen physiological function
Bind to the peptide fragment of foreign proteins for presentation to specific T-cells
MHC are clustered in a small segment of what chromosome
Chromosome 6.
The 3 classes of MHC and their function
I & II(cell surface glycoprotein)
III(component of compliment system)
Mention the 3 antigens in Class I of MHC
HLA-A,B,C
Mention the 3 antigens in Class II of MHC
HLA-DP,DQ,DR
Mention all cells that have the class-I MHC
All Nucleated cells
CD8+
Platelets
Cells having class II
Macrophages
Dendritic ells
CD4
B cells
Hypersensitive rxn can be divided into
Immediate
Delayed
Antibody dysfunction
Immediate hypersensitivity has how many types
Type 1-3
Ppts of type 1- Anaphylaxis
Atopy
Anaphylaxis
Asthma
Rxn of Ag and Ab on MAST cells and BASOPHILS.
Mediated by IgE(effector)
It is local- eye, Nose,
Mention the phases of Type-1 hypersensitivity rxn
Early
Late
Mediators of TYPE-1 hypersensitivity
Leucotrienes
Histamine
Cytokine
What drugs stimulates Type 1 rxn
Codeine
Morphine
Clinical Examples of Type-1 hypersensitivity rxn
Local- allergic rhinitis
Some Bronchial asthma
Urticaria
Systemic- penicillin allergy
Type 2- Antibody dependent cell mediated cytotoxic rxn ppts.
Cells Predisposed to phagocytocis
by humoral antibodies
Cytotoxicity is mediated by NK,macrophages,PMNs
Clinical examples of type-2 rxn
Transfusion rxn
Erythroblastosis fetalis
Autoimmune Haemolytic anaemia
Pemphigus
Type 3- immune complex clinical example-:
Acute Glomerulonephritis
Effector of immune complex rxn
IgG and complement
Type 4- cell-mediated rxn(delayed)
Delayed type- CD4+
Direct cell cytotoxicity- by CD8+
Clinical examples of type IV
Contact dermatitis
Type V-autoimmune disease
Grave’s disease
Myasthenia gravis
Effectors of type V
IgG or IgM
What is immunologic tolerance?
State of an individual inability to develop a immune response to a specific antigen.
Self tolerance
Lack of responsive to an individual antigen
Primary immunodeficiency is almost
Genetically determined
Secondary immunodeficiency is caused by
Complications of infections Malnutrition Aging Side effects of immunosuppressant Chemotherapy for cancer AIDS