Innate Immunity Cellular Responses - Revision history

Bara at 18:08, 18 May 2012

2012-05-18T18:08:19Z

Bara: /* Neutrophils */

2012-05-18T18:02:22Z

Neutrophils

Bara: /* Neutrophils */

2012-05-18T18:01:42Z

Neutrophils

Bara at 17:50, 18 May 2012

2012-05-18T17:50:28Z

Rjfrancisrvc: /* Neutrophils */

2012-05-03T11:52:38Z

Neutrophils

Rjfrancisrvc: /* Neutrophils */

2012-05-03T11:51:47Z

Neutrophils

Rjfrancisrvc: /* Basophils / Mast Cells */

2012-05-02T11:30:16Z

Basophils / Mast Cells

Rjfrancisrvc: /* Basophils / Mast Cells */

2012-05-02T11:29:09Z

Basophils / Mast Cells

Rjfrancisrvc: /* Basophils / Mast Cells */

2012-05-02T11:24:07Z

Basophils / Mast Cells

Rjfrancisrvc: /* Eosinophils */

2012-05-02T11:07:44Z

Eosinophils

@@ Line 1: / Line 1: @@
 ==Introduction==
-[[Image:LH Macrophage Histology.jpg|thumb|right|125px|<p>'''Macrophage'''</p><sup>© Nottingham Uni</sup>]]
+[[Image:LH Macrophage Histology.jpg|thumb|right|200px|<p>'''Macrophage'''</p><sup>© Nottingham Uni</sup>]]
 Pathogens can invade the body if a breach occurs in the barriers formed by the skin and mucus membranes, for example a wound, they must be detected and destroyed by cellular and [[Humoral Factors of Innate Immune System|humoral]] means.<br />
 <br />
@@ Line 16: / Line 16: @@
 ==[[Macrophages|Macrophages]]==
-[[Image:Monocytes.jpg|thumb|right|150px|Monocytes - J. Bredl, RVC 2008]]
+[[Image:Monocytes.jpg|thumb|right|200px|Monocytes - J. Bredl, RVC 2008]]
 The innate cellular response begins with recognition and phagocytosis by macrophages that precide in the tissue where the wound occurs. The populations of distinct, tissue-specific macrophages that are present are the:
 * Alveolar macrophages (lung)
@@ Line 34: / Line 34: @@
 ==[[Neutrophils|Neutrophils]]==
-[[Image:Neutrophil 2.jpg|thumb|right|150px|Neutrophils - J. Bredl, RVC 2008]]
+[[Image:Neutrophil 2.jpg|thumb|right|200px|Neutrophils - J. Bredl, RVC 2008]]
 [[Neutrophils|Neutrophils]] are the principal, highly active '''[[Phagocytosis|phagocytes]]''' in the blood and comprise 30-70% of all white blood cells depending on species. Their main function is to kill and digest microbes in a similar way as macrophages. They also have another function of extracellular bacterial killing by disrupting bacterial membranes by the secretion of small antibacterial peptides, for example defensins and bactenecins.
 <br />
@@ Line 50: / Line 50: @@
 ==[[Eosinophils|Eosinophils]]==
-[[Image:Eosinophil.jpg|thumb|right|150px|Eosinophil - J. Bredl, RVC 2008]]
+[[Image:Eosinophil.jpg|thumb|right|200px|Eosinophil - J. Bredl, RVC 2008]]
 Eosinophils are less common than [[Neutrophils|neutrophils]], with eosinophils making up less than 5% of the leukocytes in normal blood. They are still described as granulocytes but they are not phagocytic.
 <br />
@@ Line 62: / Line 62: @@
 ==[[Basophils|Basophils]] / [[Mast Cells|Mast Cells]]==
-[[Image:Basophil and Lymphocyte.jpg|thumb|right|150px|Basophil - J. Bredl, RVC 2008]]
+[[Image:Basophil and Lymphocyte.jpg|thumb|right|200px|Basophil - J. Bredl, RVC 2008]]
 The basophils and the mast cells are principally localised at epithelial surfaces with very small numbers present in blood, making up less than 0.5% of circulating leukocytes.
 <br />
@@ Line 69: / Line 69: @@
 <br />
 <br />
-The first is the induction of [[:Category:Inflammation|acute inflammation]]. They do this through the production of '''[[Cytokines|cytokines]]''' by the mast cells in response to trauma and/or bacterial infection which then induces a classical acute inflammatory response.
+The first is the induction of [[Acute Inflammation - Introduction|acute inflammation]]. They do this through the production of '''[[Cytokines|cytokines]]''' by the mast cells in response to trauma and/or bacterial infection which then induces a classical acute inflammatory response.
 <br />
 <br />
-The second is to respond to parasite infection. They do this specifically by interacting with the Fc region of the [[Immunoglobulins|IgE]] class of antibody. When the IgE then comes into contact with antigen, Fc receptors on the surface of the Mast cells and basophils can interact with the antibody which causes the mast cells and basophils to degranulate. This causes the release enzymes and vasoactive substances that can result in a high level of mucus secretion and smooth muscle contraction. As the granules contain a much greater concentration of these peptides, the degranulation of Mast cells and Basophils creates a much more powerful response than that by neutrophils alone (it is for this reason that they can cause Type I hypersensitivity reactions). These cells also produce factors that influence local host cell physiology
+The second is to respond to parasite infection. They do this specifically by interacting with the Fc region of the [[IgE|IgE]] class of antibody. When the IgE then comes into contact with antigen, Fc receptors on the surface of the mast cells and basophils can interact with the antibody which causes the mast cells and basophils to degranulate. This causes the release of enzymes and vasoactive substances that can result in a high level of mucus secretion and smooth muscle contraction. As the granules contain a much greater concentration of these peptides, the degranulation of mast cells and basophils creates a much more powerful response than that by neutrophils alone (it is for this reason that they can cause [[Type I Hypersensitivity|Type I hypersensitivity reactions]]). These cells also produce factors that influence local host cell physiology
 and various mediators that increase the ratio of phagocyte to microbe (in particular [[Cytokines|cytokines]]).
 <br><br>
 {{Jim Bee 2007}}
 [[Category:Innate Immune System]]

@@ Line 47: / Line 47: @@
 <br />
 <br />
-Their removal from the site after the removal of infection is an important step in the resolution of the lesion. Under physiological conditions the neutrophils undergo a process called '''apoptosis''' (or ''Programmed Cell Death''), and are then cleared by tissue macrophages ([[#Macrophages|see above]]). However, if there are too few macrophages to clear the cells, or the infection is resulting in the death of the neutrophils, they undergo a process called '''necrosis'''. When these neutrophils that have undergone necrosis accumulate at the site of infection it forms '''pus'''.
+Their removal from the site after the removal of infection is an important step in the resolution of the lesion. Under physiological conditions the neutrophils undergo a process called '''apoptosis''' (or ''Programmed Cell Death''), and are then cleared by [[#Macrophages|tissue macrophages]] (see above). However, if there are too few macrophages to clear the cells, or the infection is resulting in the death of the neutrophils, they undergo a process called '''necrosis'''. When these neutrophils that have undergone necrosis accumulate at the site of infection it forms '''pus'''.
 ==[[Eosinophils|Eosinophils]]==

@@ Line 38: / Line 38: @@
 <br />
 <br />
-Neutrophils also produce vasoactive peptides, for example, histamine and bradykinin which, as their name suggests, activate the endothelium to become more "leaky" causing a great increase in extravasation of blood granulocytes and [[Monocytes|monocytes]], and the diffusion of plasma proteins to the site of infection. These peptides, released from other cells as well as neutrophils, are responsible for the classical signs of [[Inflammation - Introduction|inflammation]]: redness ('''rubor'''), heat ('''calor'''), swelling ('''tumour'''), and pain ('''dolor'''), often accompanied by loss of function. Neutrophil activation in an inflammatory lesion also results in the release of '''prostaglandins''' which are responsible for vasoactive changes and for pain (N.B. These are reduced with cyclo-oxygenase (COX) inhibition for example with the NSAID (non-steriodal anti-inflammatory drugs)'s Aspirin and Ibuprofen).
+Neutrophils also produce vasoactive peptides, for example, histamine and bradykinin which, as their name suggests, activate the endothelium to become more "leaky" causing a great increase in extravasation of blood granulocytes and [[Monocytes|monocytes]], and the diffusion of plasma proteins to the site of infection. These peptides, released from other cells as well as neutrophils, are responsible for the classical signs of [[Inflammation - Introduction|inflammation]]: redness ('''rubor'''), heat ('''calor'''), swelling ('''tumour'''), and pain ('''dolor'''), often accompanied by loss of function. Neutrophil activation in an inflammatory lesion also results in the release of '''prostaglandins''' which are responsible for vasoactive changes and for pain (N.B. These are reduced with cyclo-oxygenase (COX) inhibition for example with the [[NSAIDs|NSAIDs]] (non-steriodal anti-inflammatory drugs) aspirin and ibuprofen).
 <br />
 <br />
-It is for the reasons above that neutrophils have been described as the archetypal cell associated with [[:Category:Inflammation|acute inflammation]].
+It is for the reasons above that neutrophils have been described as the archetypal cell associated with [[Acute Inflammation - Introduction|acute inflammation]].
 <br />
 <br />
@@ Line 47: / Line 47: @@
 <br />
 <br />
-Their removal from the site after the removal of infection is an important step in the resolution of the lesion. Under physiological conditions the neutrophils undergo a process called '''apoptosis''' (or ''Programmed Cell Death''), and are then cleared by tissue macrophages (see above). However, if there are too few macrophages to clear the cells, or the infection is resulting in the death of the neutrophils, they undergo a process called '''necrosis'''. When these neutrophils that have undergone necrosis accumulate at the site of infection it forms '''pus'''.
+Their removal from the site after the removal of infection is an important step in the resolution of the lesion. Under physiological conditions the neutrophils undergo a process called '''apoptosis''' (or ''Programmed Cell Death''), and are then cleared by tissue macrophages ([[#Macrophages|see above]]). However, if there are too few macrophages to clear the cells, or the infection is resulting in the death of the neutrophils, they undergo a process called '''necrosis'''. When these neutrophils that have undergone necrosis accumulate at the site of infection it forms '''pus'''.
 ==[[Eosinophils|Eosinophils]]==

@@ Line 2: / Line 2: @@
 [[Image:LH Macrophage Histology.jpg|thumb|right|125px|<p>'''Macrophage'''</p><sup>© Nottingham Uni</sup>]]
-Pathogens can invade the body if a breach occurs in the barriers formed by the skin and mucus membranes, for example a wound, they must be detected and destroyed by cellular and humoral means.<br />
+Pathogens can invade the body if a breach occurs in the barriers formed by the skin and mucus membranes, for example a wound, they must be detected and destroyed by cellular and [[Humoral Factors of Innate Immune System|humoral]] means.<br />
 <br />
 The cells involved in the cellular response to a wound are:
-* Tissue mast cells and '''[[Macrophages|macrophages]]''' that initially phagocytose and detect bacteria or fungi<br />
+* Tissue [[Mast Cells|mast cells]] and '''[[Macrophages|macrophages]]''' that initially [[Phagocytosis|phagocytose]] and detect [[Bacteria|bacteria]] or [[fungi]]<br />
 <br />
-* The blood granulocytes, or Polymorphonuclear (PMN: multi-lobed nuclei) Cells
+* The blood [[Blood Cells - Overview#White Blood Cells|granulocytes]], or polymorphonuclear (PMN: multi-lobed nuclei) cells
-** The '''[[Neutrophils|Neutrophils]]''' are the most abundant as they are the primary cells that phagocytose bacteria, and the larger fungi
+** The '''[[Neutrophils|neutrophils]]''' are the most abundant as they are the primary cells that phagocytose bacteria, and the larger fungi
-** The '''[[Eosinophils|Eosinophils]]''' and '''[[Basophils|Basophils]] / [[Mast Cells| mast cells]]''' are only needed in rare circumstances as they are for killing parasites by the release of granules (exocytosis).
+** The '''[[Eosinophils|eosinophils]]''' and '''[[Basophils|basophils]] / [[Mast Cells| mast cells]]''' are only needed in rare circumstances as they are for killing parasites by the release of granules (exocytosis).
 <br />
 * Blood '''[[Monocytes|monocytes]]''': phagocytose bacteria
 <br />
-The main role of the innate cellular response is to delay systemic infection until the [[Adaptive Immune System|adaptive response]] can back it up with a more specific attack
+The main role of the innate cellular response is to delay systemic infection until the [[Adaptive Immune System|adaptive response]] can back it up with a more specific attack.
 ==[[Macrophages|Macrophages]]==
@@ Line 22: / Line 22: @@
 * Glomerular macrophages (kidney)
 * Hepatic Küpffer cells (liver)
-* CNS microglia (Central Nervous System: Brain and Spinal Cord)
+* CNS microglia (central nervous system: brain and spinal cord)
 * Sinus-lining macrophages of the lymph nodes and spleen
 <br />
-When [[Phagocytosis|phagocytosis]] of the bacteria or fungi by the tissue macrophages occurs they release a number of [[Cytokines|cytokines]] that have many effects. The first being the activation of the endothelium that results in the expression of adhesion molecules that allow leukocytes, in particular the [[Neutrophils|neutrophils]] to bind to the endothelium from the bloodstream and the subsequent [[Neutrophils|extravasation]] (movement out of the bloodstream). Once the leukocytes are out of the bloodstream, the cytokines released by the tissue macrophages act as chemoattractants that enable the chemotaxis of the leukocytes to the site of infection.
+When [[Phagocytosis|phagocytosis]] of the bacteria or fungi by the tissue macrophages occurs, they release a number of [[Cytokines|cytokines]] that have many effects. The first being the activation of the endothelium that results in the expression of adhesion molecules that allow leukocytes, in particular the [[Neutrophils|neutrophils]] to bind to the endothelium from the bloodstream and the subsequent [[Neutrophils#Exocytosis|extravasation]] (movement out of the bloodstream). Once the leukocytes are out of the bloodstream, the cytokines released by the tissue macrophages act as chemoattractants that enable the chemotaxis of the leukocytes to the site of infection.
 <br />
 <br />

@@ Line 38: / Line 38: @@
 <br />
 <br />
-Neutrophils also produce vasoactive peptides, for example, histamine and bradykinin which, as their name suggests, activate the endothelium to become more "leaky" causing a great increase in extravasation of blood granulocytes and [[Monocytes|monocytes]], and the diffusion of plasma proteins to the site of infection. These peptides, released from other cells as well as neutrophils, are responsible for the classical signs of [[Introduction - Inflammation|inflammation]]: redness ('''rubor'''), heat ('''calor'''), swelling ('''tumour'''), and pain ('''dolor'''), often accompanied by loss of function. Neutrophil activation in an inflammatory lesion also results in the release of '''prostaglandins''' which are responsible for vasoactive changes and for pain (N.B. These are reduced with cyclo-oxygenase (COX) inhibition for example with the NSAID (non-steriodal anti-inflammatory drugs)'s Aspirin and Ibuprofen).
+Neutrophils also produce vasoactive peptides, for example, histamine and bradykinin which, as their name suggests, activate the endothelium to become more "leaky" causing a great increase in extravasation of blood granulocytes and [[Monocytes|monocytes]], and the diffusion of plasma proteins to the site of infection. These peptides, released from other cells as well as neutrophils, are responsible for the classical signs of [[Inflammation - Introduction|inflammation]]: redness ('''rubor'''), heat ('''calor'''), swelling ('''tumour'''), and pain ('''dolor'''), often accompanied by loss of function. Neutrophil activation in an inflammatory lesion also results in the release of '''prostaglandins''' which are responsible for vasoactive changes and for pain (N.B. These are reduced with cyclo-oxygenase (COX) inhibition for example with the NSAID (non-steriodal anti-inflammatory drugs)'s Aspirin and Ibuprofen).
 <br />
 <br />

@@ Line 63: / Line 63: @@
 ==[[Basophils|Basophils]] / [[Mast Cells|Mast Cells]]==
 [[Image:Basophil and Lymphocyte.jpg|thumb|right|150px|Basophil - J. Bredl, RVC 2008]]
-* Basophils/mast cells are principally localised at epithelial surfaces
+The basophils and the mast cells are principally localised at epithelial surfaces with very small numbers present in blood, making up less than 0.5% of circulating leukocytes.
-** Very small numbers are present in blood
+<br />
-*** Less than 0.5% circulating leukocytes
+<br />
-* They have two principal functions:
+These two cell types have two principal functions:
-*# Induction of [[:Category:Inflammation|acute inflammation]]
+<br />
-*#* Trauma and/ or bacterial infection causes the production of '''cytokines''' by the mast cells that induce a classical acute inflammatory response
+<br />
-*# Response to parasite infection
+The first is the induction of [[:Category:Inflammation|acute inflammation]]. They do this through the production of '''[[Cytokines|cytokines]]''' by the mast cells in response to trauma and/or bacterial infection which then induces a classical acute inflammatory response.
-*#* Specific [[Immunoglobulins|IgE]] binds cells
+<br />
-*#* Subsequent contact with antigen causes the mast cells to degranulate
+<br />
-*#* Release enzymes and vasoactive substances that can result in a high level of mucus secretion and smooth muscle contraction
+The second is to respond to parasite infection. They do this specifically by interacting with the Fc region of the [[Immunoglobulins|IgE]] class of antibody. When the IgE then comes into subsequent contact with antigen this causes the mast cells and basophils to degranulate. This causes the release enzymes and vasoactive substances that can result in a high level of mucus secretion and smooth muscle contraction. As the granules contain a much greater concentration of these peptides, the degranulation of Mast cells and Basophils creates a much more powerful response than that by neutrophils alone. These cells also produce factors that influence local host cell physiology
-* Also produce factors that influence local host cell physiology
+and various mediators that increase the ratio of phagocyte to microbe (in particular [[Cytokines|cytokines]]).
 <br><br>
 {{Jim Bee 2007}}
 [[Category:Innate Immune System]]

@@ Line 51: / Line 51: @@
 ==[[Eosinophils|Eosinophils]]==
 [[Image:Eosinophil.jpg|thumb|right|150px|Eosinophil - J. Bredl, RVC 2008]]
-* Eosinophils are less common than [[Neutrophils|neutrophils]], and they are not phagocytic
+Eosinophils are less common than [[Neutrophils|neutrophils]], with eosinophils making up less than 5% of the leukocytes in normal blood. They are still described as granulocytes but they are not phagocytic.
-** Make up <5% of the leukocytes in normal blood
+<br />
-* Eosinophil numbers are increased:
+<br />
-** Slightly during the resolution phase of inflammation
+It has been found that eosinophil numbers are increased slightly during the resolution phase of inflammation, but many-fold in parasite-infected animals. It is therefore the presence of a large proportion of eosinophils in a blood smear that is highly indicative of parasitaemia.
-** Many-fold in parasite-infected animals
+<br />
-*** The presence of a large proportion of eosinophils in a blood smear is highly indicative of parasitaemia
+<br />
-* Mainly function by targeting the surface of parasites by means of specific antibody or complement
+The eosinophils mainly function by targeting the surface of parasites by means of a specific [[Immunoglobulins|antibody]] or [[Complement|complement component]]. Once the parasite has been recognised the eosinophils release, through a process called exocytosis (the fusion of granules to the plasma membrane), a large range of toxic molecules that break down the parasite integument.<br />
-** Release a large range of toxic molecules that break down the parasite integument
+<br />
-* Prominent in [[:Category:Allergic Diseases|allergic]] (anaphylactic) reactions
+Intrestingly, eosinophils are also prominent in [[:Category:Allergic Diseases|allergic]] (anaphylactic) reactions.
 ==[[Basophils|Basophils]] / [[Mast Cells|Mast Cells]]==