Immune System

Secondary Lymphoid Tissues

Derivatives of Monocytes

Name Site
Macrophage
Histiocyte
Tissue
Microglia Brain
Alveolar macrophage Lung
Kupffer cell Liver
Mesangial cell Kidney
Osteoclast Bone
Langerhans cell Skin
Hofbauer cell Placenta

Leukocyte Functions

Step Endothelium Leukocyte
Rolling Selectin SLX
Adhesion CAM Integrin
Diapedesis PECAM-1 [CD31] PECAM-1 [CD31]
Migration C5a & IL-8 -
Phagocytosis - -
Fusion - Microtubule
Degradation - NADPH oxidase
  - Myeloperoxidase

Toll-Like Receptors (TLR) on Antigen-Presenting Cells (APC)

Complement Systems

Pathway Targets Cascade
Classic Antigen-antibody complexes 142356789
Alternative Spontaneous and microbial surfaces 3BD356789
Lectin Microbial surfaces M42356789

Respiratory [Oxidative] Burst

Functions of Complements & Cytokines

Molecule Functions
C3a ~ C5a Anaphylaxis
C5a Chemotaxis
C3b Opsonization
C5b ~ C9b Membrane attack complex (MAC)
IL-1 Fever
IL-2 T cell growth
IL-3 Bone marrow growth
IL-4 IgE production
IL-5 IgA production
IL-6 Acute-phase protein production
IL-8 Chemotaxis

Cytokine Secretion

Mechanism Cell Cytokines
General Neutrophil -
Cellular :: adaptive Th1 cell IL-2 & IL-3 & IFN-γ
  Tc cell IL-2 & IL-3
Cellular :: innate Macrophage IL-1 & IL-6 & IL-8 & IL-12 & TNF-α
  NK cell IL-2 & TNF-α & IFN-γ
Humoral :: adaptive Th2 cell IL-2 & IL-3 & IL-4 & IL-5 & IL-6 & IL-10
  B cell IL-1
Humoral :: innate Basophil IL-4
  Eosinophil -

Cytokine Interactions

Mechanism Cell Inducers Inhibitors
General Neutrophil IL-1 & IL-6 & IL-8 IL-10 & TGF-β
Cellular :: adaptive Th1 cell IL-2 & IL-12 & IFN-γ IL-4 & IL-10
  Tc cell IL-2 & IL-12 -
Cellular :: innate Macrophage IFN-γ -
  NK cell IL-2 & IL-12 & IFN-γ -
Humoral :: adaptive Th2 cell IL-2 & IL-4 IFN-γ
  B cell IL-3 & IL-4 & IL-5 & IL-6 -
Humoral :: innate Basophil IL-4 -
  Eosinophil IL-5 -

Cell Surface Proteins

Mechanism Cell Signal 1 Signal 2 Others
General Neutrophil - - -
Cellular :: adaptive Th1 cell TCR & CD3 & CD4 CD28 & CD40L -
  Tc cell TCR & CD3 & CD8 CD28 -
Cellular :: innate Macrophage MHC-1 & MHC-2 B7 & CD40 CD14
  NK cell - - CD16 & CD56
Humoral :: adaptive Th2 cell TCR & CD3 & CD4 CD28 & CD40L -
  B cell MHC-1 & MHC-2 B7 & CD40 CD19 & CD20 & CD21
Humoral :: innate Basophil - - -
  Eosinophil - - -

Structure of MHC

Structure of Lymphocyte Receptors

Development of Lymphocytes

Activation of Lymphocytes

Immunoglobulins {MDGEA}

Immunoglobulin Members
IgM 5
IgD 1
IgG 1
IgE 1
IgA 2

Mechanisms of Antibody Diversity

Mechanism Enzymes
N-nucleotide addition Terminal deoxynucleotidyl transferase (TdT)
Random recombination of VJ or VDJ genes RAG-1 & RAG-2
Random combination of heavy and light chains -
Somatic hypermutation -