B20. Immune System of Birds

Question 1

Lymphoid organs Bird

Answer 1

• Primary: thymus, bone marrow and bursa fabricius. 
• Secondary 
o Spleen 
o Bone marrow 
o Haderian gland 
o Scattered payer’s patches 
o Caecal tonsils 
o Meckel’s diverticulum 
o Oesophageal and pyloric tonsils 
o BALT (bronchus), CALT (conjuctiva), GALT (gut) 
• They have no lymph nodes!

Question 2

Different B cell maturation Bird

Answer 2

• B cell production in 2 steps
1. bone marrow: 160IgM molecules can be prod, 10 light chains and 150 heavy chains. This is not enough of course, 2nd step of maturation is needed to give higher diversity
2. fabrica bursae: extra gene sequences are inserted in the V segment. Based on the number how many that were successful from the first step different number of sequences will be inserted in V segment.
• Very important in birds! If something attacks the bone marrow no B cells will be prod at all. If pathogenic material is in the bursa diversity will be affected.
• First atb produced is IgM (as in mammals), later changes to IgY.

o Do not have/undetected IgG, (IgY = avian IgG)

• IgY - first isolated from egg yolk, present in high concentration. Has all the function of IgG in mammals and some subclasses (IgA, anitparasitic and allergic reactions).
• IgB - in the bile, protection of the gut of galliforms (chicken like), produced in the liver
• IgN - anseriforms (duck like), shorter with 2 domains, similar function to IgM/Y,
• IgM can also be present on the mucosa surfaces in mammals, no function except for in the pigs. Protective effect in the upper respiratory tract.
• In birds several different Ig have a protective role together.

Question 3

Immune system of fish

Answer 3

• Gill: pillar cell – MHCII
• Mucus: antimicrobial peptids, lisozyme
• ALTs (associated lymphoid tissue)
• Head, kidney: regulation, hemopoietic tasks, melanomacrophag centrum
• Thymus
• Spleen: melanomacrophag centrum
• Liver

Question 4

PRR fish

Answer 4

o Soluble: LPS-binding protein, pentraxin, complement, collektin
o Association with cells on membranes: epithelial cells, phagocytes, dendritic cells

Question 5

Cytokines fish

Answer 5

o IL-1
o TNFα, TNF-like proteins
o IL-6, IL-8, IL-10, IL-12
o INF-like proteins

Question 6

immunoglobulins fish

Answer 6

o H (70kDa) and L chain (25kDa)  
o Restricted variability 
o Little amount (1 group)

Question 7

Complement system fish

Answer 7

o Classical, alternative and lectin(?)

o C3 isoform

Question 8

Immune system of bees

Answer 8

• Hive is densely crowded, moist and warm
• Fewer immune genes than other insects
• The colony is a complex superorganism
• Pathogens
• Antimicrobial secretions in the saliva
• Propolis
• Colony organisation
• Hygienic behavior
• Sacrifice themselves

Question 9

Microbiome of honeybee

Answer 9

Crop
Ileum
Midgut
Rectum