Chronic Inflammation¶

Presence of lymphocytes at the Site of Injury

graph TD
    X[Chronic Inflammation] ==>  X1[Non-Granulomatous reaction] & X2[granulomatous reaction];
    x1==>x1a[killing virus infected cells ,Cancer cells etc...]
    X2==>X2a[Caseating ] & X2b [Non-caseaus Granulomatous reaction]
    X2a==>x2a1[TB ,fungal infection];
    X2b ==> x2b1[Auto-immune reaction= Sarcoidosis,Cron's disease];

Antigen Presentation of Macrophages¶

First signal(cd4+ recognition of MHC-2)
Second Signal CD28 and B7 binding
1. Phagocytosed antigen is presented on MHC-2 by macrophage to CD4+ Lymphocytes T-cell receptor.
2. CD4+ Receptor checks for MHC-2
3. T-cell receptor binds to antigen on MHC-2
4. Recognition of antigen activates secondary signalling by B7and CD28 binding
5. third signalrelases cytokines from macrophage IL-1.6,TNF-ALPHA
6. CD4+ Cells release IL-2 and INF-Gamma for macrophage activation

CD4+ Cell subtypes¶

1.Th1- intracellular (CD8+ Activation by IL-2 ,Supermacrophage from IFN-GAMMAfor Granulomatous reaction) 2.TH2 - Extracellular (IL-4,5,10...) 3. TH17 - Neutrophil 4. THfh - hypersensitivity 5. Treg - anti immune response

CD4 activation by B-cells¶

First signal (CD4 receptor and MHC 2 Recognition)
Second Signal (CD40 and CD40L binding )