Immuno - Lymphocytes (Intro) Flashcards
Pg. 193-195 Sections include: Innate vs. adaptive immunity MHC I and II HLA subtypes associated with diseases Natural killer cells Major functions of B and T cells
What is the difference between innate and adaptive immunity in terms of the development of receptors involved?
INNATE - Receptors that recognize pathogen are germline encoded. ADAPTIVE - Receptors that recognize pathogens undergo V(D)J recombination during lymphocyte development.
What is the difference between innate and adaptive immunity in terms of response to pathogen?
INNATE - Nonspecific. Occurs rapidly ( minutes to hours); ADAPTIVE - highly specific, refined over time. Develops over long periods; memory response faster and more robust
What is the difference between innate and adaptive immunity in terms of types of cells involved?
INNATE - Consists of neutrophils, macrophages, monocytes, dendritic cells, natural killer cells (lymphoid origin), and complement. ADAPTIVE - Consists of T cells, B cells, and circulating antibody.
What does MHC stand for? What are the types of MHC? What encodes them? What function does they serve?
MHC = major histocompatibility complex; MHC I and II; Encoded by human leukocyte antigen (HLA) genes; Present antigen fragments to T cells and bind TCR
What are the genes that code for MHC I versus MHC II?
MHC I = HLA-A, HLA-B, HLA-C; MHC II = HLA-DR, HLA-DP, HLA-DQ
What does MHC I versus MHC II bind?
MHC I binds TCR and CD8; MHC II binds TCR and CD4
Where is MHC I versus MHC II expressed?
MHC I is expressed on all nucleated cells (i.e., not expressed on RBC); MHC II is expressed only on antigen-presenting cells (APCs)
What is the difference between MHC I versus MHC II in terms of how antigen is loaded?
MHC I = Antigen peptides loaded in RER after delivery via TAP peptide transporter; MHC II = Antigen is loaded following release of invariant chain in an acidified endosome.
Which type of MHC mediates viral immunity?
MHC I
Which type of MHC pairs with Beta2-microglobulin? What function does this pairing serve?
MHC I pairs with Beta2-microglobulin (aids in transport to cell surface)
Draw a visual of MHC I, labeling the following: (1) Peptide-binding groove (2) alpha (3) Beta2-microglobulin (4) Cell membrane.
See p. 194 in First Aid for first visual on right
Draw a visual of MHC II, labeling the following: (1) Peptide-binding groove (2) alpha (3) Beta (4) Cell membrane.
See p. 194 in First Aid for second visual on right
Which disease is associated with HLA subtype A3?
Hemochromatosis
Which diseases are associated with HLA subtype B27?
Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter’s syndrome; Think: “PAIR”
Which disease is associated with HLA subtype DQ2/DQ8?
Celiac disease
Which diseases are associated with HLA subtype DR2?
Multiple sclerosis, hay fever, SLE, Goopasture’s; Also Celiac disease associated with DQ2/DQ8
Which diseases are associated with HLA subtype DR3?
Diabetes mellitus type I, SLE, Graves’ disease
Which diseases are associated with HLA subtype DR4?
Rheumatoid arthritis, diabetes mellitus type I
Which diseases are associated with HLA subtype DR5?
Pernicious anemia –> B12 deficiency, Hashimoto’s thyroiditis
With what HLA subtype is Hemochromatosis associated?
A3
With what HLA subtype are the following diseases associated: Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter’s syndrome?
B27; Think: “PAIR”
With what HLA subtype is Celiac disease associated?
DQ2/ DQ8
With what HLA subtype are the following diseases associated: Multiple sclerosis, hay fever, SLE, Goopasture’s?
DR2
With what HLA subtype are Diabetes mellitus type I, SLE, and Graves’ disease associated?
DR3
With what HLA subtype are Rheumatoid arthritis and Diabetes mellitus type I associated?
DR4; think: “there are 4 walls in a rheum”
With what HLA subtype are Pernicious anemia –> B12 deficiency and Hashimoto’s thyroiditis associated?
DR5
With which 2 HLA subtypes is diabetes mellitus type I associated? What other diseases are associated with these 2 HLA subtypes?
DR3 - Graves’ disease, SLE; DR4 - Rheumatoid arthritis
What function do Natural killer cells serve and via what mechanism(s)?
Use perforin and granzymes to induce apoptosis of virally infected cells and tumor cells
What is unique about Natural killer cells in terms of its classification/role?
Only lymphocyte member of innate immune system
Which cytokines enhance the activity of natural killer cells?
IL-2, IL-12, IFN-beta, and IFN-alpha
In what 2 contexts are natural killer cells induced to kill?
Induced to kill when exposed (1) to a nonspecific activation signal on target cell and/or (2) to an absence of class I MHC on target cell surface
What are the 3 major functions of B cells?
(1) Recognize antigen - undergo somatic hypermutation to optimize antigen specificity (2) Produce antibody - differentiate into plasma cells to secrete specific immunoglobulins (3) Maintain immunologic memory - memory B cells persist and accelerate future response to antigen
What are the 4 major functions of T cells?
(1) CD4+ T cells help B cells make antibody and produce cytokines to activate other cells of immune system. (2) CD8+ T cells kill virus-infected cells directly (3) Delayed cell-mediated hypersensitivity (type IV) (4) Acute and chronic cellular organ rejection
What function(s) do CD4+ T cells serve?
CD4+ T cells help B cells make antibody and produce cytokines to activate other cells of immune system.
What function do CD8+ T cells serve?
CD8+ T cells kill virus-infected cells directly
With what type of hypersensitivity are T cells involved?
Delayed cell-mediated hypersensitivity (type IV)
What function do T cells serve that is relevant to transplantation?
Acute and chronic cellular organ rejection
To which type of immunity do physical barriers apply? Give 2 examples of such barriers.
Innate immunity; epithelial junctions, mucus
What are secreted proteins in innate versus adaptive immunity?
INNATE: lysozyme, complement, CRP, defensins; ADAPTIVE: immunoglobulins
What are key features of pathogen recognition for innate versus adaptive immunity?
INNATE - Toll like receptors (TLRs): pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs). Examples of PAMPs include LPS (gram negative), flagellin (bacteria), ssRNA (viruses); ADAPTIVE - Memory cells: activated B and T cells; subsequent exposure to a previously encountered antigen => stronger, quicker immune response
