Why is immunology important? Flashcards
which low grade pathogens / commensals do humans have?
what do HIV cells do (basic)? what do people die of?
- bacteria in gut (enterobacteriaceae)
- staphylococci on skin
- Klebsiella/Neisseria/Pneomococci in throat
if they get into wrong place can cause harm
HIV kills immune cells (T-cells) - patients die of opportunisitic infections
what happens if born without immune system? name?
how can u treat?
- *severe combined immunodeficiency (SCID)**
- *- no T cell immunity
- no B / antibody cell immunity**
- likely to have recurrent bacterial, viral or fungal infections
treatment:
- bone marrow transplant to replace immune system
- in single gene defect: can give adenovirus
where do all cells of immune system come from?
a stem cell in bone marrow
what are cells of the adaptive immunity?
what is cell differentiation pathway from pleuripotent stem cell to adaptive immunity cells?
pluripotent cells –> lymphoid stem cell –> B cell (makes antibodies)
- *or
- -> T cell: - CD4 Helper
- CD8 Cytotoxic**
both are types of lymphocyte
structure of antibody?
antigen binding site is combination of light chain and heavy chain
where do T cells mature / occur from?
where are B cells made
what type of tissues are these ^ ?
where is thymus?
- *T cells:** Thymus
- *B cells:** Bone marrow
B cells (& bone marrow) and T cells (Thymus) are Primary Lymphoid Tissues: active in making cells without antigenic stimulation
Thymus: located in mediasternum
where are secondary lymphoid tissues / lymph nodes located?
why are lymph nodes located where they are ?
- axillar
- groin
- head and neck
- gut
- popliteal
- spleen
- peyers pach on small intestine
- appendix
lymph node locations: infection will take antigens and dendritic cells into lymph nodes - generate immune response. provide environment for immune reaction
- how does immune system recognise pathogens?
- ## whats an antigen? different types?
- immune system recognises pathogens by responding to non-self (self v non self)
- *- antigens:** anything that elicits immune response
- self antigen: immune system responds to self :(
- foreign antigen: antigen from outside body
what are the receptors found on lymphocytes? - explain basic overview of adaptive immune system
what receptors found in innate immune system? on which cells/
- *adaptive immunity**:
- lymphocytes are covered in receptors:
- antigen specific T cell receptor (TcR): two types - αβ and γδ (gamma delta)
-
antigen specific B cell receptor (BcR): immunglobin on B cell surface
1. once B or T cells is activated by recognising antigen: resting cell -> activated cell. massive cell division. makes cytokines, come killer cells and make antibodies - *innate immunity:**
- phagocytes, macrophages & neutrophils receptors:
- *- pattern recognition receptors (PRR)
- Fc receptors**
- response immediately
explain mechanism of skin macrophages producing cytokines -
skin macrophages:
- covered in molecules (Toll like receptors) that recognise pathogen associated molecular patterns (PAMPs) (things only found in bacteria / viruses like flagella)
- signalling through Toll like receptors causes them to be activated and make pro-inflammatory cytokines
- produce cytokines (TNF-a & IL-1B). cytokines work on endothelial cells - make luminal surface sticky: causes neutrophils to stick (how they know where to go)
what are white blood cells?
A type of blood cell that is made in the bone marrow and found in the blood and lymph tissue. White blood cells are part of the body’s immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (T cells and B cells).
what is inflammation?
when white cells leave the blood and move into the tissues - in process of gettting rid of pathogens, kill normal tissue too
what are neutrophils?
- lobed nucleus
- filled with granules with pre-formed mediators
- engulf bacteria due to:
- free radicals, neutrophil elastase, neutrophil collagenase, gelatinases and more..)
- die in tissue
- destroy normal tissue
what is the innate immune system role? (basic)
what is the adaptive immune system role? (basic)
- innate immune system: destroys number of pathogens v early on in infection
- adaptive immune system:
what happens when a B cell become activated?
when B cell activated:
- divide lots (aka clonal expansion)
- B cells can become:
- plasma cells (make antibodies)
- memory cells
- *when T cell activated:**
- clonal expansion (due to IL-2)
