This is the process by which the body eliminates self-reactive lymphocytes by deleting their offspring. In humans, clonal deletion occurs in the thymus for T lymphocytes and in the bone marrow for B lymphocytes. The process however occurs differently in both type of cells.
Figure 1, Clonal deletion process
CLASS SWITCHING:
It is a process by which a plasma cell combines its variable region gene for a different Fc region and begins secreting a new class of antibodies. The most common switch is plasma cell switching to synthesize immunoglobulin G. This type of switch is a switch to the gene for heavy gamma chain.
Figure 2, class switching
APOPTOSIS:
The simplest definition of apoptosis is programmed cell suicide. This process is usually triggered when perforin (target cell with protein) molecules form into a tubular structure in the target cell's membrane, forming a channel through which granzyme enters the cells, thus triggering apoptosis.
Figure 3, the process of Apoptosis
CHEMOTAXIS:
It is the movement of a cell either towards a chemical stimulus (positive chemotaxis) or away from a chemical stimulus (negative chemotaxis). Positive chemotaxis in phagocytes involves the use of pseudopodia to move towards microorganisms where there is infection.
Figure 4, Chemotaxis
REFERENCES
Bauman RW. Microbiology with disease by Taxonomy. 3rd ed. San Francisco (CA): Pearson; 2011.
PICTURES
Figure 1: http://www.google.com/imgres?sa=X&biw=1600&bih=759&tbm=isch&tbnid=wph2RrvlKb0nhM:&imgrefurl=http://www.nature.com/nri/journal/v4/n10/box/nri1456_BX3.html&docid=GPd41NMEQEbyYM&imgurl=http://www.nature.com/nri/journal/v4/n10/images/nri1456-i3.jpg&w=600&h=372&ei=hDBoUce3IvXG4APOuIHYBQ&zoom=1&iact=rc&dur=187&page=1&tbnh=150&tbnw=242&start=0&ndsp=32&ved=1t:429,r:4,s:0,i:94&tx=58&ty=59
Figure 2: http://www.google.com/imgres?biw=1600&bih=759&tbm=isch&tbnid=wZmThaAac8CAxM:&imgrefurl=http://www.studyblue.com/notes/note/n/im1-07-08-t-cells/deck/1073514&docid=F3ATTfTAodZQKM&imgurl=http://classconnection.s3.amazonaws.com/33/flashcards/602033/jpg/important_th2_cytokines1315462704587.jpg&w=1110&h=905&ei=gjNoUbbtDdfJ4AP3h4CgBw&zoom=1&iact=rc&dur=266&page=1&tbnh=153&tbnw=188&start=0&ndsp=36&ved=1t:429,r:10,s:0,i:109&tx=91&ty=103
Figure 3: http://www.google.com/imgres?biw=1600&bih=759&tbm=isch&tbnid=RpLwOJmpk9y93M:&imgrefurl=http://www.copewithcytokines.de/cope.cgi%3Fkey%3DApoptosis&docid=q_lIeTIc7SE9vM&imgurl=http://www.copewithcytokines.de/apoptosis.gif&w=405&h=237&ei=TThoUaeyNs_I4AP22YH4Aw&zoom=1&iact=hc&vpx=365&vpy=135&dur=1014&hovh=172&hovw=294&tx=126&ty=141&page=1&tbnh=121&tbnw=201&start=0&ndsp=37&ved=1t:429,r:3,s:0,i:88
Figure 4: https://en.wikipedia.org/wiki/File:Chtxphenomen1.png
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