THEPHYSIOLOGY

OF IMMUNITY

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THEPHYSIOLOGY

OF IMMUNITY

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Delfin Arnel D. Razon, MD., DPBA

Department of Medical Physiology

Pamantasan ng Lungsod ng Maynila

College of Medicine

Delfin Arnel D. Razon, MD., DPBA

Department of Medical Physiology

Pamantasan ng Lungsod ng Maynila

College of Medicine

Cells Mediating the Immune Response:

Cells Mediating the Immune Response:

Leukocytes granulocytes

monocytes lymphocytes

B cellsT cells

cytotoxic T cellshelper T cellssuppressor T cells

NK cells Plasma cells Macrophages Mast cells

Leukocytes granulocytes

monocytes lymphocytes

B cellsT cells

cytotoxic T cellshelper T cellssuppressor T cells

NK cells Plasma cells Macrophages Mast cells

IMMUNE SYSTEM

Innate immunity Acquired immunity defences at body surfaces

phagocytosis Humoral Immunity

inflammation Cellular Immunity

complement activation

IMMUNE SYSTEM

Innate immunity Acquired immunity defences at body surfaces

phagocytosis Humoral Immunity

inflammation Cellular Immunity

complement activation

PHAGOCYTOSISPHAGOCYTOSIS

• 3 Important Cells 1. Neutrophils

Circulating pool

Marginated pool

.respiratory burst

.signal transduction/stimulus response

coupling

2. Circulating monocytes

3. Fixed tissue macrophages

• 3 Important Cells 1. Neutrophils

Circulating pool

Marginated pool

.respiratory burst

.signal transduction/stimulus response

coupling

2. Circulating monocytes

3. Fixed tissue macrophages

ACUIRED IMMUNITY(ADAPTIVE IMMUNITY)

ACUIRED IMMUNITY(ADAPTIVE IMMUNITY)

• LYMPHOCYTES• T-cells• B-cells

.plasma cellsIgG IgDIgA IgEIgM

. NK cells

• RECEPTORS• recognition

• LYMPHOCYTES• T-cells• B-cells

.plasma cellsIgG IgDIgA IgEIgM

. NK cells

• RECEPTORS• recognition

HUMAN T cellHUMAN T cell

Human ImmunoglobulinsAntibody Location Function

IgA Gut, respiratory tract and urogenital tract mucosa

-prevents colonization of pathogens -localized protection in external secretions

IgD Antigen receptor on B cells IgE - complement fixation

majority of Ab based immunity

-binds to allergens and triggers histamine release -involved in allergy protection vs parasitic worms

IgG - - complement fixation - majority of Ab based immunity

IgM Surfaces of Bcells/secreted form

- Complement fixation

- Pathogen elimination in early stages of B cells response

T cell responseANTIGEN PRESENTATION

T cell responseANTIGEN PRESENTATION

• APCs• MHCs

MHC class I- all nucleated cells of

the body

MHC class II- macrophages, macro-

phage-like cells, B cells• MHC restrictions

Helper T cells = MHC class II restricted

Cytotoxic Tcells = MHC class I restricted

• APCs• MHCs

MHC class I- all nucleated cells of

the body

MHC class II- macrophages, macro-

phage-like cells, B cells• MHC restrictions

Helper T cells = MHC class II restricted

Cytotoxic Tcells = MHC class I restricted

NK cells physiologic role

CLONAL DELETION

And

CLONAL INACTIVATION

CLONAL DELETION

And

CLONAL INACTIVATION

ENDEND