IMMUNOLOUNOLOGY OF FISHES

1. Introduction to fish
immunology

2. Introduction
The word immune is came from the latin word
immunis : free of burden,
&
the term immunology is the study of defence
mechanisms against infectious disease.
The immune system is a complex network of cells
and proteins that defends the body against
infection.
The immune system keeps a record of every germ
(microbe) it has ever defeated so it can recognise
and destroy the microbe quickly if it enters the body
again.

3. A system that protects against disease by identifying and killing pathogens and
tumor cells. It detects a wide variety of agents, from viruses to parasitic worms.
An immune response is an elaborate interplay between
antigen and the component of innate and adaptive
immune systems.
Immune system
Immune response

4. Innate/non-specific/Genetic Immunity
• Immunity an organism is born with.
• Genetically determined.
Adaptive/Specific/Acquired Immunity
Immunity that an organism develops during lifetime.
 Not genetically determined.

5. Rauta et al. (2012)
Immune organs in different vertebrates

6. The first line of defense is provided
by a set of mechanical, chemical, and
biologic barriers that protect the
body. If these barriers are breached,
the second and third lines of
protective systems are activated: first
the innate immune system and then
the adaptive immune system.
Threats to the fishes

7. Protection from and response to microbial invasion

8. Defensive mechanisms
granuloma is a collection of inflammatory
cells, predominantly mature macrophages
that form an aggregate in response to an
antigen. This antigen can include invading
bacteria, fungi, foreign bodies, and
immune complexes
The purpose of the granuloma is to isolate
this antigen from the body and to facilitate
its eradication
One of the most intrinsic
immune defense mechanisms
of multicellular organisms is
to sacrifice infected cells for
the benefit of the
remaining cells
Microbes face numerous obstacles
for reproducing and establishing long
term infections in fish.

9. 10 organ for phagocytosis
Developing B lymphoid cells
Formation of IgM and immune memory
Central organ for immune-endocrine
interactions and neuroimmuno-endocrine
connections
Head
10 organ for phagocytosis
Produces T lymphocytes
Involved in stimulation of phagocytosis
Stimulate antibody production by Bells
20 immune organ act as scavenging organ
Play a vital role in haematopoiesis,
-antigen degradation
-antibody production and
-antigen trapping

10. Innate immune system
Cells Monocytes/macrophages,
granulocytes, NK cells
T-cells, B-cells and APC
Humoral Complement system, opsonins,
interferon, transferrin, lectins, anti-
proteases, lysozymes and
antimicrobial peptides
Ig molecule
Regulator
s
Cytokines/ chemokines Cytokines
Kinetics Fast Slow
Adaptive immune system

11. Innate immune system
Physical components Humoral components Cellular components
1st line Defence 2nd line Defence
 Scales
 Mucous surface of skin
Gills
Epidermis
Growth inhibitors
 Transferrin
 Interferon
Protease inhibitors
Lytic enzyme
• Lysozyme
• Chitinase
Lectins
Agglutinins and precipitins
• Pentraxins (CRP and SAP)
• Opsonins
Natural antibodies
Antibacterial peptides
Complement
Cytokines/chemokines
Phagocytic cells
• Granulocytes (Neutrophils)
• Monocytes/Macrophages
• Non-specific cytotoxic cells
Epithelial cells
Dendritic cells

12. Adaptive immune system
Humoral components Cellular components
3rd line Defence
Immunoglobulins
-IgM
- IgD
-IgT
-IgZ
Cytokines
-TNF
-IL
T-cells (T-cell receptors)
 B-cells (B-cell receptors)
 Antigen presenting cells
(APCs)
1010
(Khan, 2000)

14. THAT’S ALL FOR TODAY