The immune response White Blood cell types

1. The immune responseWhite Blood cell types

2. Pluripotent stem cells (in bone marrow) Lymphoid cells Myeloid stem cells Granular Lymphocytes (NK cells) Mast cells Basophils Neutrophils Cytotoxic T-cell Eosinophils T- Lymphocytes(mature in thymus) Helper T-cell Monocyte Suppressor cell T-memory cell Macrophage Dendritic cells B- Lymphocytes(mature in bone marrow) Plasma b cell Memory b cell

3. Mast cells • Found in connective tissues of the body • Release histamine to start inflammation response Return

4. Basophils • Effectively circulating mast cells • Send signals to activate / recruit other myeloid cells Return

5. Neutrophils • Phagocytosis • Most common of the myeloid cells • Perform phagocytosis Return

6. Eosinophils • Phagocytosis • Release chemical to reduce inflammation response Return

7. Monocyte • Very inactive until stimulated by antigen with non self HMC • Will differentiate into either dendritic or macrophage • Very large Dendritic cells Macrophage • Phagocytosis • Antigen presenting cell (engulf foreign objects and displays antigen markers to T and B cells) • Found outside body on mucus membranes, etc • Phagocytosis • Found in blood stream • Antigen presenting cell (engulf foreign objects and displays antigen markers to T and B cells) Return

8. Natural killer cells • Cause cell apoptosis on diseased cells • These cells with have foreign antigens on surface • Secretes two chemical1. punches hole in cell2. sends signal to self destruct Return

9. Cytotoxic T-Cell • Destroys Virus infected / cancerous cells (similar to the NK cells) Return

10. Helper T-Cell • Activate Cytotoxic T cells and Macrophages Return

11. Suppressor / Regulatory T cells • Stops the immune response (opposite to T-cells) Return

12. T-memory cells • Remain long after immune response • Numbers increase rapidly when exposed to previously seen antigen (provide memory for immune system) Return

13. Plasma b cells • Produce large amounts of antibodies (proteins) which assist in the phagocytosis process Return

14. Memory b cells • Activate plasma b cells that create antibodies specific to the antigen detected Return

15. Clonal selection • Both b and t cells under go a process by which their Antigen receptors are randomly altered during every division. • This creates an array of different antigen binding sites in the body which is important due to binding specificity (much like enzymes)

16. The Humoral response Killing foreign cells Macrophage / Dendritic cells consume pathogens and place their antigen on their own surface These markers are delivered to the helper T cells in the lymph nodes Lymph nodes

17. In the lymph nodes The Macrophages / Dendritic cells present the antigens to the Helper T-cells

18. Cytotoxic t-cells and Plasma b cells B-cells will bind with antigens around the body however they will wait motionless unless a Helper T cell finds the same antigen

19. Helper T - Cells If the Helper T cell is presented with the same antigen as a b-cell has found it will send an INTERLUKEN which is a signal for action

20. B-cell proliferation Once given the signal, The b cells clone themselves into more plasma b-cells and start producing antibodies at a rapid rate (10k per second) The antibodies - Neutralise toxins- Prevent further binding - attract phagocytic cells

21. Antibodies 5 classes of antibodiesG,M,A,D,E G – lots made, can cross membranes easilyM – type made firstE – Attach to mast cells and make them more sensitive. Over production can lead to allergies

22. Memory b-cells Some of the b-cells created are called memory b-cellsThese cells are long lasting (up to 10 years) and will act as the “memory” of the immune system The next time that particular type of antigen enters the body, it only needs to come in contact with one memory b cell and the proliferation process will occur again This will result in a far faster destruction of the pathogen in future

23. After memory b-cells have been created, the pathogen is far more likely to be discovered quickly and eliminated When a pathogen enters the body for the first time it will go un challenged until both a helper T cell and a b-cell find it

24. The Cell Mediated ResponseKilling our bad cells T-cell receptor- Antigen receptor Cytotoxic T-cells have two receptors The CD8 receptor helps the cell identify whether a cell belongs to the body or not by checking the cells MHC The Antigen receptor allows the t-cell to determine whether a pathogen has been present and left its markers on the cell CD8 receptor- MHC recognition

25. If the CD8 Receptors match – means it is a self cell If the T-cell receptor matches – means the t cell will wait for a signal from a helper t cell to indicate that this is in fact an antigen that needs to be destroyed Diseased cell

26. If a helper t cell has been presented with an antigen that is the same as the markers on the cell it will send a CYTOKINE to allow the destruction of the cell Diseased cell

27. The cytotoxic t-cell will then use two chemicals to destroy the cell, as well as create many copies of itself which will seek out other identical cells and do the same Diseased cell

28. overview

29. overview

30. overview