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IMMUNOLOGY.pptx

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Cytokines are a group of low molecular weight proteins that are secreted by white blood cells and other cells to regulate immune and inflammatory responses. They work as molecular messengers to communicate between cells. Cytokines bind to specific receptors on target cells and trigger signaling pathways that alter gene expression. Some key properties of cytokines include pleiotropy, redundancy, synergy, and antagonism. Cytokines can act locally on nearby cells (autocrine and paracrine action) or distantly after entering circulation (endocrine action).

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IMMUNOLOGY.pptx
The word CYTOKINES are derived from the greek word CYTO refers to movement. cytokines are a group of protiens . Which includes low molecular glycoprotiens (or) regulatory protiens which play a significant role in cell-to- cell communication.
in response to stimuli , cytokines are by WBC and other cells . It workes as a moleculer messenger, derived from a variety of cells which includes most cells , lymphocytes , endothelical cells. The complex interaction between lymphoid cells, heamopoietic cells, and inflammatory cells is madiated by CYTOKINES
IMMUNOLOGY.pptx
target specific and induce signal transduction : Cytokines binds to specific receptor on the cell membrane of target cell which triggers signal transduction pathway that ultimately alter gene expression in target cell. The cytokines and their fully assembled receptors exhibit very high affinity for each other and deliver intracellular signals.
Cytokines are a group of low- molecular weight regulatory proteins secreted by WBC and other cell in the body . Cytokines seceration is very specific and self limited event as because they are not usually stored as performed molecules . Cytokines synthesis is intiated by new gene transcription as a consequence of celluar activation . Once synthesized cytokines are rapidly secreted, resulting in a brust of release when needed .
after secretion, cytokines (almost 60 different types of cytokines) regulate immune and inflammatory reactions. Cytokines bind to specific receptor on the membrane of target cells, triggering signal transductions pathways that ultimately alter gene expression in the target cell. The nature of the targetcell for a particular cytokine is determinedby the presence of specific due to thier
high affinity for which picomolar concentrations of cytokines can mediate a biological effect. CYTOKINES ACTIONS MAY BE LOCAL OR SYSTEMIC : 1. AUTOCRINE ACTIONS: most of the cytokines act close to where they are produced , a particular cytokine when binds to receptors on the membrane of the same cell from where it has been is called autocrine action.
2. PARACRINE ACTION : when secreted cytokines bind to receptors on a target cell in close proximity to the producer cells its called paracrine action . 3. ENDOCRINE ACTION : in most of the cases cytokines act on cells that are in contact with the cytokine producers but when cytokines are produced in large amounts. It may enter the circulation and act at a distance from the site of production. This is called endocrine action.
IMMUNOLOGY.pptx
Cytokines often influence the synthesis and actions of other cytokines and different immune cells . The ability of one cytokine to stimulate production of others , leads to cascade in which a second or third cytokine may mediate the biological effects of the first. Cytokines regulate the intensity and duration of the immune response by stimulating or inhibiting the activation , proliferation and differentiation of various cells.
the cytokines secreted by a single lymphocyte following antigen specific activation can influence the activity of various cells involved in the immune response . FOR EXAMPLE, cytokines produced by activated Th cells (T- helper cells) can influence the activity of B- cells , Tc cells natural killer cells ( NK cells) , macrophages granulocytes and haematopoietic stem cells. This means that it activates an entire network of interacting cells.
Cytokines exhibit the attributes of PLEIOTROPY, REDUNDANCY, SYNERGY AND ANTAGONISM. PLEIOTROPY: pleiotropism refers to the ability of one cytokine to act on different cell types which action ; fewer exhibit endocrine action allows a cytokine to mediate diverse biological effects . REDUNDANCY : redundancy refers to the property of multiple cytokines i.e .two or more cytokines having the same functional effects . The property of cytokine makes it difficult to explain a particular activity to a single cytokine.
SYNERGY : synergism exhibit to the phenomenon when the combined effect of two cytokines on cellular activity is greater. Than the additive effects of the invidual cytokines. ANTAGONISM : antagonism indicates the property that is just opposite to the synorgism as in this case, the effects of one cytokine inhibit or offset the effect of another cytokine.
IMMUNOLOGY.pptx
Cytokine activity is also being regulated by external signals , the expression of cytokine receptors vary and also the responsiveness of cells to cytokines. as for ex, stimulation of Tor B lymphocytes by antigen leads to increased expression of cytokine receptors Many of the changes in gene expression induced by cytokine result in differentiation of T and B- lymphocytes and activation of effector cells such as macrophages
besides activation, cellular responses to cytokines can also include feedback inhibitory signals to the cytokine activity . these mechanisms include cytokine induction of gene encoding inhibitors of the cytokine receptors. these inhibitors may inhibit the function of cytokine receptors expressed on the cell surface , molecules that block interactions of signalling kinases phosphates REFERENCE: https//www.biologydiscussion.com https//onlinebiologynotes.com https//microbiologynotes.com THANK YOU

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IMMUNOLOGY.pptx

  • 2. The word CYTOKINES are derived from the greek word CYTO refers to movement. cytokines are a group of protiens . Which includes low molecular glycoprotiens (or) regulatory protiens which play a significant role in cell-to- cell communication.
  • 3. in response to stimuli , cytokines are by WBC and other cells . It workes as a moleculer messenger, derived from a variety of cells which includes most cells , lymphocytes , endothelical cells. The complex interaction between lymphoid cells, heamopoietic cells, and inflammatory cells is madiated by CYTOKINES
  • 5. target specific and induce signal transduction : Cytokines binds to specific receptor on the cell membrane of target cell which triggers signal transduction pathway that ultimately alter gene expression in target cell. The cytokines and their fully assembled receptors exhibit very high affinity for each other and deliver intracellular signals.
  • 6. Cytokines are a group of low- molecular weight regulatory proteins secreted by WBC and other cell in the body . Cytokines seceration is very specific and self limited event as because they are not usually stored as performed molecules . Cytokines synthesis is intiated by new gene transcription as a consequence of celluar activation . Once synthesized cytokines are rapidly secreted, resulting in a brust of release when needed .
  • 7. after secretion, cytokines (almost 60 different types of cytokines) regulate immune and inflammatory reactions. Cytokines bind to specific receptor on the membrane of target cells, triggering signal transductions pathways that ultimately alter gene expression in the target cell. The nature of the targetcell for a particular cytokine is determinedby the presence of specific due to thier
  • 8. high affinity for which picomolar concentrations of cytokines can mediate a biological effect. CYTOKINES ACTIONS MAY BE LOCAL OR SYSTEMIC : 1. AUTOCRINE ACTIONS: most of the cytokines act close to where they are produced , a particular cytokine when binds to receptors on the membrane of the same cell from where it has been is called autocrine action.
  • 9. 2. PARACRINE ACTION : when secreted cytokines bind to receptors on a target cell in close proximity to the producer cells its called paracrine action . 3. ENDOCRINE ACTION : in most of the cases cytokines act on cells that are in contact with the cytokine producers but when cytokines are produced in large amounts. It may enter the circulation and act at a distance from the site of production. This is called endocrine action.
  • 11. Cytokines often influence the synthesis and actions of other cytokines and different immune cells . The ability of one cytokine to stimulate production of others , leads to cascade in which a second or third cytokine may mediate the biological effects of the first. Cytokines regulate the intensity and duration of the immune response by stimulating or inhibiting the activation , proliferation and differentiation of various cells.
  • 12. the cytokines secreted by a single lymphocyte following antigen specific activation can influence the activity of various cells involved in the immune response . FOR EXAMPLE, cytokines produced by activated Th cells (T- helper cells) can influence the activity of B- cells , Tc cells natural killer cells ( NK cells) , macrophages granulocytes and haematopoietic stem cells. This means that it activates an entire network of interacting cells.
  • 13. Cytokines exhibit the attributes of PLEIOTROPY, REDUNDANCY, SYNERGY AND ANTAGONISM. PLEIOTROPY: pleiotropism refers to the ability of one cytokine to act on different cell types which action ; fewer exhibit endocrine action allows a cytokine to mediate diverse biological effects . REDUNDANCY : redundancy refers to the property of multiple cytokines i.e .two or more cytokines having the same functional effects . The property of cytokine makes it difficult to explain a particular activity to a single cytokine.
  • 14. SYNERGY : synergism exhibit to the phenomenon when the combined effect of two cytokines on cellular activity is greater. Than the additive effects of the invidual cytokines. ANTAGONISM : antagonism indicates the property that is just opposite to the synorgism as in this case, the effects of one cytokine inhibit or offset the effect of another cytokine.
  • 16. Cytokine activity is also being regulated by external signals , the expression of cytokine receptors vary and also the responsiveness of cells to cytokines. as for ex, stimulation of Tor B lymphocytes by antigen leads to increased expression of cytokine receptors Many of the changes in gene expression induced by cytokine result in differentiation of T and B- lymphocytes and activation of effector cells such as macrophages
  • 17. besides activation, cellular responses to cytokines can also include feedback inhibitory signals to the cytokine activity . these mechanisms include cytokine induction of gene encoding inhibitors of the cytokine receptors. these inhibitors may inhibit the function of cytokine receptors expressed on the cell surface , molecules that block interactions of signalling kinases phosphates REFERENCE: https//www.biologydiscussion.com https//onlinebiologynotes.com https//microbiologynotes.com THANK YOU