basics Flashcards
<p>Describe the development of immune cells?</p>
<p>a pluripotent stem cell develops into:</p>
<ul><li>premyeloid progenitor → neutrophils</li><li>Lymphocyte progenitors → T cells (thymus) or B cells (bone marrow)</li><li>Premonocyte progenitor → macrophage</li></ul>
<p>T cell can develop into: Helper cell (Th1 and Th2), Cytotoxic cell or memory cell</p>
<p>B cells produce antibodies and become plasma cell</p>
<p>what kind of stem cell do immune cells begin as?</p>
<p>haematopoietic stem cell</p>
<p>(common progenitor cell)</p>
<p>list the myeloid lineage</p>
<p>megakaryocyte</p>
<p>erythrocyte</p>
<p>mast cell</p>
<p>myeloblast - basophil, neutrophil, eosinophil, monocyte</p>
<p>where do myeloid lineage mature</p>
<p>bone marrow</p>
<p>where do lymphoid lineage mature</p>
<p>t cells - thymus</p>
<p>b cells - bone marrow</p>
<p>how do innate and adaptive immunity differ</p>
<p>speed of response time</p>
<p>cellular components</p>
<p>function</p>
<p>how are cells distinguished as healthy or harmful</p>
<p>through recognition of antigens</p>
<p>describe the antigen presentation of t lymphocytes</p>
<p>any nucleated host cell can present intracellular antigens via their MHC I molecule to CD8+ cytotoxic T lymphocytes</p>
<p>professional antigen presenting cells can present extracellular antigens via their MHC II to CD4+ helper T lymphocytes</p>
<p>what does a haematopoietic stem cell divide into</p>
<p>myeloid and lymphoid progenitor cells</p>
<p>list the lymphoid lineage</p>
<p>natural killer cells</p>
<p>t lymphocytes</p>
<p>b lymphocytes</p>
<p>where do t and b cells further differentiate</p>
<p>secondary lymphoid organs</p>
<p>what are the divisions of the immune system</p>
<p>innate immunity</p>
<p>adaptive immunity</p>
<p>describe the innate response</p>
<p>first line of defence</p>
<p>fast non specific response</p>
<p>describe the adaptive response</p>
<p>second line of defence</p>
<p>slow specific response</p>
<ul><li>cell mediated (t lymphocytes)</li><li>humoral (b lymphocytes)</li></ul>
<p>what do all nucleated cells display</p>
<p>self markers via a cell membrane protein called the major histocompatibility complex I (MHC I)</p>
<p>in humans what is the MHC also referred to as</p>
<p>human leukocyte antigen</p>
<p>what are the two types of MHC</p>
<p>MHC I - cell surface of all nucleated cells in body, present self markers or intracellular pathogens</p>
<p></p>
<p>MHC II - on professional antigen presenting cells, present extracellular pathogens</p>
<p>examples of professional antigen presenting cells</p>
<p>dendritic cells</p>
<p>macrophages</p>
<p>b lymphocytes</p>
<p>define immunological tolerance</p>
<p>immune system learns to become tolerant or unresponsive to a particular antigen</p>
<p>central or peripheral tolerance</p>
<p>central tolerance</p>
<p>developed within the primary lymphoid organs (bone marrow and thymus) where immature immune cells are taught to be able to discriminate between host and non host</p>
<p>prevents the release of self reactive t and b lymphocytes into circulation</p>
<p>peripheral tolerance</p>
<p>developed within secondary lymphoid organs</p>
<p>mature immune cells released into circulation</p>
<p>if they act inappropriately, they are made useless, destroyed or suppressed by regulatory t lymphocytes</p>
how does the innate immune system recognise invading pathogens
pattern recognition receptors (PRRs) located on cell surface membrane
examples of PRRs
toll like receptors (TLR)
- most commonly found on monocytes, macrophages and dendritic cells
C-type lectin receptors (CLR)
examples of molecular motifs recognised by PRRs
pathogen associated molecular pattern (PAMP)
- lipopolysaccharide (LPS)
damage associated molecular pattern (DAMP)
- dna, histones, ATP
