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![Receptor for Fc of IgG (interacts with Ag) [CD32---- Fc of Ab-Ag]
B cell
CD 32 or FcRII
Fc of Ab-Ag
Ab
Ag](https://image.slidesharecdn.com/cellsoftheimmunesystem2-191121065209/85/Cells-of-the-immune-system-14-320.jpg)
![Receptor for Fc of IgG (interacts with Ag) [CD32---- Fc of Ab-Ag]
B cell
CD 32 or FcRII
Fc of Ab-Ag
Ab
Ag](https://image.slidesharecdn.com/cellsoftheimmunesystem2-191121065209/75/Cells-of-the-immune-system-14-2048.jpg)
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Similar to Cells of the immune system
Cells of the immune system
- 1. 1. Lymphoid cellsT cells 4. Mast cells B cells NK cells (Null cells) 2. Mononuclear cells Monocytes 5. Dendritic cells Langerhans cells Interstitial DC Macrophages Interdigitating DC Circulating DC 3. Granulocytic cells Neutrophils Eosinophil Basophil Cells of the immune system
- 2. B lymphocytes Site ofmaturation in birds - bursa of Fabricius In mammalian species- bone marrow 1.5 x 105Ab/B cell
- 3. B cells actas APC (Antigen presenting cells) What is the role of APC They digest the Ag and present to T Cells and help in T cell activation
- 4. Antigen presentation toTH cell
- 5.
- 7. Antigen Presentation Antigen presentationby a B cell Naïve cell activated cell
- 8. Antigen presenting cells -Processthe Ag and present with MHC Professional APC Non-Professional APC 1. Macrophages 2. Dendritic cells 3. B cells APC -Present Ag only for a short period -Eg., thymic epithelial cells vascular endothelial cells
- 9. Naïve B cell Ag Activated macrophage Activated T cell If inappropriate signalsis received If appropriate signals is received Die by apoptosis division and differenti ation Plasma cells memory cells Interact with Activation of a Naive B cell
- 11. Surface markers displayedon B cell
- 12. B cell TH orTC Cell B7-1 ------CD28 (TH) B7-2 ---- CTLA-4 (TC) CD40--------CD40L (TH) Ab (app 1.5 x 105/cell) Ag Class II MHC Presents Ag Molecules/markers displayed on B cells B cell- an APC- Process and present Ag CTLA-4 (cytotoxic T-lymphocyte associated molecule-4)
- 13. B cell CR1 (orCD35) and CR2 (or CD21) Receptor for complements CR1/CR2 Complements CR1/CR2 Complements
- 14. Receptor for Fcof IgG (interacts with Ag) [CD32---- Fc of Ab-Ag] B cell CD 32 or FcRII Fc of Ab-Ag Ab Ag
- 16. B cell THCellCD40 ------CD40L B cell- activated Development into plasma or memory cells Activation of B cells by the activated TH cell Activated TH cell Ag
- 17. T lymphocytes - Maturationin Thymus B cells T cells Have on surface Ab TCR Binds with Ag Ag Ab and TCR - structurally different - similarity in structure of Ag binding site B cell Ag Ab T cell Ag TCR
- 18. Ab on Bcells TCR on T cells Bind to free Ag -Cannot bind to free Ag - Bind to Ag displayed with MHC molecules APC/ Virus infected cell/ Cancer cell/ grafts Ag MHC T cell TCR B cells Ab Ag
- 20. Antigen presenting cells -Processthe Ag and present with MHC Professional APC Non-Professional APC 1. Macrophages 2. Dendritic cells 3. B cells APC -Present Ag only for a short period -Eg., thymic epithelial cells vascular endothelial cells
- 21. Surface markers onT cells lymphocyte function-associated antigen-1 (LFA -1) ICAM-1 (Inter-Cellular Adhesion Molecule 1)
- 23. CD4 present in THcells (Class II MHC restricted cells) a membrane glycoprotein bind to Ag presented with class II MHC TH CD4 CII MHC APC Ag
- 24. CD8 present in TCcells (Class I MHC restricted cells) a membrane glycoprotein bind to Ag presented with class I MHC TC CD8 CI MHC Infected cell Ag
- 25. TH CD4 CII MHC APC Ag TC CD8 CI MHC Infectedcell Ag Class II MHC restricted cells Class I MHC restricted cells
- 26. CD45 -a signaltransduction molecule -Present in all differentiated hematopoietic cells except plasma cells and erythrocytes -Is a type I transmembrane protein -Is involved in the activation of both T and B cells
- 27. TC and THcells
- 28. Activation of THcell TH cell activation by Ag + Class II MHC Activation of TH cell Secrete cytokines Activate B cell, T cells and other imune response cells
- 29. . TH cells Produce TH1 andTH2 response Depending on cytokines which activates the TH Eg., TH –if promoted/activated by IL-12 IL-4 TH1 response TH2 response produce
- 30.
- 31. Activation of TCcells Activation of TC cells by 1. Ag + Class I MHC in infected cell 2. Cytokines Differentiation of TC into CTL (cytotoxic T lymphocytes) Secrete cytokines Eliminates target cell
- 33. Suppressor T cells -Alsocalled as Regulatory T cells -Suppress the activation of the immune system -maintains tolerance to self-antigens Suppressor T cells Suppresses immune system So, can be used for treating autoimmune diseases inducing tolerance to transplantation
- 35. Suppressor cells: Both lowand high doses of antigen may induce suppressor T cells (Regulatory T cells) which can specifically suppress immune responses of both B and T cells either directly or by production of cytokines, most importantly, TGF-b (transforming growth factor) and IL-10.
- 36. Development of TScells -occurs in thymus Majority of TS- express high level of CD4 and CD25 - also transcription factor FOXP3 (forkhead box p3). Minor population of TS- express CD8 and Foxp3
- 37. Other properties ofTS Cells - Express low levels of CD 127 - inability to produce IL-2
- 38. 1. Lymphoid cellsT cells 4. Mast cells B cells NK cells (Null cells) 2. Mononuclear cells Monocytes 5. Dendritic cells Langerhans cells Interstitial DC Macrophages Interdigitating DC Circulating DC 3. Granulocytic cells Neutrophils Eosinophil Basophil Cells of the immune system
- 39. Null cells -Are largegranular lymphocytes - has CD 16 as surface marker
- 40. • Do NotExpress Classical Lymphocyte Markers like Ab Ag binding receptor membrane molecules • Has no immunological specificity and memory (since it lacks Ag binding receptor) • Predominant type of null cell is NK Cells (CD56) Null Cells B/T cell Ag Ab/TCR 1. Lymphoid cells T cells B cells NK cells (Null cells)
- 41. Natural Killer cells Arelarger granular lymphocytes Present in 5 -10% in human peripheral blood 1st described in 1976 Eliminate Tumor Cells and Virally Infected Cells Reduction of Class I MHC Can Activate Them (since Tumor Cells and Virally Infected Cells express low levels of Class I MHC to escape from TC)
- 42. Target cell Low ClassI MHC Surface Ag Ag-Ab (Ab bound to Ag) NK cells recognize the target cell by Surface Ag Low Class I MHC Ag-Ab
- 43. Express Low AffinityFcRIII (CD16) Using CD16 They Can Carry Out ADCC Target cell Ag-Ab Fc of Ab ----bind with CD16 NK Cell Target cell destroyed (Antibody dependent cell mediated cytotoxicity) Ag
- 45. Natural killer T(NKT) cells Has the property of both T cell and NK cells (but different from T cells and NK cells) Present in 0.2% of all peripheral blood T cells Like T cells, they have TCR NKT cell TCR recognize CD1d target cell T cell TCR recognize Class I/II MHC target cell
- 46. NKT cell TCR recognize antigenic lipidsand glycolipids + CD1d target cell T cell TCR recognize Antigenic Peptide+ Class I/II MHC target cell
- 47. Other properties ofNKT cells Like NK cells they express natural killer (NK) cell-associated markers like 1. NK1.1 (CD161) 2. CD 16 3. CD 56 4. Also produce granzymes like NK cell
- 48. Different forms ofNKT NKT cells include 1. NK1.1+ 2. NK1.1- 3. CD4+ 4. CD4- 5. CD8+ and 6. CD8- cells
- 49. On activation NKT Produce largequantities of interferon- IL-4 GMCSF (granulocyte-macrophage colony- stimulating factor ) cytokines and chemokines (such as IL-2 and TNF-a).
- 50. On pathogen entry Tcells development takes some time Within that time, there is rapid release of cytokines (such as IL-2, IFN-gamma, TNF-alpha, and IL-4) by NKT, that promote different immune responses. NKT Release cytokines (such as IL-2, IFN-gamma, TNF- alpha, and IL-4)
- 51. An overview ofthe immune responses (Layer 1)
- 52. An overview ofthe immune responses (Layer 2)
- 53. An overview ofthe immune responses (Layer 3)
- 54. An overview ofthe immune responses (Layer 4)