Basic Immunology Flashcards
How many proteins make a histone?
8
What amino acids make up histones?
Lysine and arginine
What does a nucleosome comprise of?
Histone, condensed DNA wrapped twice around histone
What is chromatin comprised of?
Nucleosomes and linker DNA like beads on a string
Name 2 essential amino acids
Lysine and leucine
What occurs during S phase of mitosis?
Genomic material and histones are made
How does mitochondria DNA differ from other DNA?
Mitochondria have their own DNA, the DNA is circular, do not use histones
What are the primary organs of the immune system? (Primary lymphoid organs)
Bone Marrow
Thymus
What are the secondary organs of the immune system? (Secondary lymphoid organ)
Spleen
Lymph nodes
Tonsils
Peyer’s patches
What is the function of the bone marrow?
Creation of immune cells
(Lymphocytes, macrophages, neutrophils)
What are the parts of the lymph node
Capsule with trabeculae
Cortex that contains follicles
Paracortex
Medulla (medullary sinus and cords)
Efferents
Afferents
What is the function of the thymus?
Maturation of T cells
What are the functions of the lymph nodes?
Activate immune response
Circulation of B and T cells
Filtration by macrophages
What cells are found in the cortex?
B lymphocytes
What is found in the paracortex?
venules and T lymphocytes
What cells are found in the medullary sinus?
Macrophages and reticular cells
What cells are found in the medullary cords?
Closely packed Lymphocytes and plasma cells
What can happen to paracortex when certain infection and viral illnesses occur?
Hyperplasia aka clinically- lymphadenopathy
Differences between primary and secondary follicles
Primary - dense, quiescent
Secondary - pale germinal centers and active
What do the medullary sinuses connect with?
Efferent lymphatics
Role of venules in paracortex
T and B lymphocytes enter lymph nodes from blood through these
Components of innate immunity
Neutrophils
Macrophages
Monocytes
Dendritic cells
Natural killer cells
Complement
Physical epithelial barriers
Secreted enzymes
Components of adaptive immunity
T cells
B cells
Circulating antibodies
Innate immunity response to pathogens
Non specific
Rapid - minutes to hours
No memory response
Adaptive immunity response to pathogens
Highly specific
Develops over long periods
Good memory response
Proteins secreted in innate immunity
Lysozyme
Complement
CRP
Defensins
Cytokines
Secreted proteins in adaptive immunity
Immunoglobulins
Cytokines
Features of pathogen recognition in innate immunity
Toll like receptors
Pattern recognition receptors - for pathogen associated molecular patterns (PAMPS)
Examples of pathogen associated molecular receptors
Lipopolyssacharride - gram -ve bacteria
Flagellin - bacteria
Nucleic acids - Virus
Features of pattern recognition in adaptive immunity
Memory cells - aka activated B and T cells (due to precious encounter with antigen)
STRONG, quicker immune response
Immune privilege?
Chemical and physical changes that reduce immune response to foreign antigens to reduce damage that would occur due to inflammation
Immune privilege occurs in which organs
Eye
Placenta
Brain
Testes
What are major histocompatibility complex I and II
Cell surface proteins encoded by HLA genes
Role of major histocompatibility complex I and II
Present antigen fragments to T cells and bind T cell receptors
Genetic loci for MHC I
HLA - A
HLA - B
HLA - C
Genetic loci for MHC II
HLA - DP
HLA - DQ
HLA - DR
What does MHC I bind to
T cell receptors
CD8
What does MHC II bind to
T cell receptors
CD4
Structure of MHC I
1 long chain
1 short chain
Structure of MHC II
2 equal length chains (2 alpha and 2 beta)
Role of MHC I
Present endogenous antigens to CD8 cytotoxic T cells
Role of MHC II
Present exogenous antigens to CD4 helper T cells
Protein associated with MHC I
B2 microglobulin
Disease associated with HLA-B27
PAIR
Psoriatic arthritis
Ankylosis spondylitis
Inflammatory bowel disease
Reactive arthritis
Disease associated with HLA-B57
Abacavir hypersensitivity
Disease associated with HLA-DQ2/DQ8
Coeliac disease
Disease associated with HLA-DR3
T1DM
SLE
Graves’ disease
Hashimoto thyroiditis
Addison disease
Disease associated with HLA-DR4
T1DM
Addison disease
Rheumatoid arthritis
Type of immune cells
NK, B cells, T cells - CD8 cytotoxic and CD4 helper
What triggers NK cells
Non specific activation signal when there is no inhibitory signal form MHC I
How NK cells cause cell death
Via 2 ways
Perforin granzyme B pathway
antibody dependent cell mediated cytotoxicity
How B cells work
HUMORAL IMMUNITY
Recognize and present antigen
Create plasma cells that produce antibodies
Memory developed
How CD4 helper T cells work
CELL MEDIATED IMMUNITY
CD4 helper - produce antibodies and recruits immune cells like phagocytes and leukocytes
How CD8 cyrotoxic T cells work
Cell death via perforin granzyme B pathway
