Please enable JavaScript.
Coggle requires JavaScript to display documents.
The Immune System (Acquired Immunity (Cell-Mediated Immunity (T…
-
-
-
-
- Can only differentiate between what is foreign and what is self. (Cannot differentiate between different microbes for example)
- Can recognize microbes outside and inside of cells through different receptors. (TLR and MBL vs. NOD and RIG-I, respectively)
- Has two primary functions, 1- Kill invading microbes.
2- Activate adaptive immune responses.
-
-
IL-12
- Increases the number of Th-1 cells
- Preformed,and fully active components > Act immediately. Not Specific.
- Highly specific. Takes several days to be fully functional.
-
1- Host defense against infections (Intracellular organisms like M.TB, fungi and parsites). 2- Allergy (Hypersensitiviy) (eg, poison oak). 3- Graft and tumour rejection. 4- Regulation of antibody response (help and suppression).
- Exhibit three characteristic features; 1- Remarkable diversity. 2- Long memory. 3- Exquisite specificity.
1- As part of the innate arm they ingest and kill various microbes.
2- They present antigen to T-cells which is the essential first step in activation of the adaptive arm.
1- Host defense against infections. (Opsonize bacteria, neutralize toxins and viruses)
2- Allergy (Hypersensitivity) (eg, Hay fever, Anaphylactic shock)
3- Autoimmunity.
-
-
- B cells perform two important functions during the induction process 1- Recognize antigens through their surface IgM, which act as antigen receptors. 2- Present epitopes to helpter T cells in association with MHC class II molecules.
- Not sufficient for human survival.
- B-lymphocytes can recognize any molecule through their IgM receptor. T can only recognize peptides.
- Class II MHC molecules are use by antigen presenting cells like macrophages and B lymphocytes to present processed peptides to the Th cellls
- B lymphocytes can recognize antigens directly without the need of an antigen pressenting cell. This can be followed by one of two pathways, 1- The antigen is processed and the peptide presented by surface MHC class II molecules to the Th cells. 2- The antigen is recognized by surface IgM receptors and antibodies are produced by the B lymphocytes independent of the T cells (T-cells independent antigens) (However from what I understand only IgM molecules may be produced through this second pathway. i.e No class switching)
- After the antigen has been presented by the B cells, the Th cells will produce IL-4 and IL-5 to stimulate the B cells in turn to produce abs specific to the presented antigen.
- From what I understand, IL-2 comes into play when an antigen presenting cell (Not a B lymphocyte however. A macrophage maybe. So only a feature of the cellular immunity) presents its antigen to the Th cells. IL-2 will then be released acting on the Th cell itself and on the cytotoxic T cells, resulting in proliferation of antigen-specific Th and Tc cells.
- Includes non-cellular effectors.
- The acute phase response. Plasma proteins produced by the liver. Production is stimulated the pro-inflammatory cytokines (IL-1,Il-6 and TNF)
- Some actue phase proteins like CRP and MBL act as opsonins or may activate complement.
- Defensins are highly cationic peptides present mainly in the GI and the lower respiratory tracts, which create pore in the bacterial membranes.
- Apo lipoprotein B RNA-editing enzyme (APOBEC3G). Important against infection by retroviruses, particularly HIV.
- Alpha and Beta interferons. Produced by virus-infected cells to produce and anti-viral state in adjacent cells.
- Gamma interferons have modest anti-viral activity. Instead they enhance killing by macrophages and other phagocytes, and enhance synthesis of class I and II MHC molecules.
- This makes me wonder if this second pathway can really be considered part of the adaptive immunity, which 1- Requires activation of the innate immunity first. 2- Provides long-term memory which I don't think can be achieved by IgM abs only.
-
- Tc action is directed against virus-infected cells, tumour cells and allografts. (58)
- Gamma inteferon. Enables macrophages to be more effective killes of intracellular microbes, like TB. Help B lymph class switch to produce subtypes of IgG.
- IL-2 (T-cell growth factor)
-
- Helps B-cells class switch to produce subclasses of IgG that are excellent opsonizers of bacteria. (58)
- IL-4 and IL-5. Both interleukins enhance B lymphocytes transformation to plasma cells.
-
- Both IL-4 and IL-5 enhance the defense against worms. IL-4 induces class switching to IgE and IL-5 increases the number and activity of easinophils. (58)
- IL-5 enhances gut immunity by inducting IgA class switch. (58)
- IL-17. Recruits neutrophils to the site of inflammation.
- IL-17 enhance mucosal immunity particularly in the GIT.
-
-
- Recruits neutrophils to the site of inflammation.
- Enables macrophages to be more efficient killers of intracellular organisms.
-
- Inhibits production of Th2 cells. (58)
- 65% of all T-lymphocytes.
- Predominate in the thymic medulla, tonsils and blood.