L1: Avian Immune System (Romero)

Question 1

Signs of alert in a poultry flock

Answer 1

• reduction in production or health problems
• overt signs of illness in poultry flock
• increase in daily mortality

Question 2

Primary lymphoid organs

Answer 2

Bursa of fabricius (where B cells differentiate and mature)

Thymus (T cells differentiate and mature)

Question 3

Principle sites of Ag-induced immune response

Answer 3

SECONDARY lymphoid organs:

• cecal tonsils (located at entrance to cecum)
• bone marrow
• spleen
• Harderian gland (located in the orbit)
• GALT, CALT (conjunctiva), BALT (bronchi)
• NO LYMPH NODE EQUIVALENT TO MAMMALS

Question 4

Birds also have nodular areas of lymphoid in the tracheal mucosa

Answer 4

:)

Question 5

Common physical stresses that negatively impact the immune system/reduce resistance to disease

Answer 5

Chilling
Overheating
Water dep.
Starvation
Concurrent infection
Concurrent parasitism
Humid/wet litter
Ammonia in litter

Question 6

Chilled or water-deprived chicks most likely to break with what dz

Answer 6

Clinical salmonellosis

Question 7

Clinical or subclinical coccidiosis depends on:

Answer 7

Number of ingested oocysts
low –> immunity
High –> disease

Question 8

After infection with IBV, poultry more likely to break with what dz?

Answer 8

Clinical mycoplasmoses

Question 9

Main avian antibodies and what order produced?

Answer 9

IgM, IgY (IgG), IgA

IgM is first produced –> IgY –> IgA

IgY mostly produce after secondary immunization

Question 10

Most important Ab in mucosal immunity

Answer 10

IgA

• bile is a reservoir for it
• protects mucosal surfaces against pathogens
• has ability to neutralize viruses so they can’t attach to target cells

Question 11

How is vax response/immune protection/pathogen exposure monitored in poultry industry?

Answer 11

Ab-based assays:**

• Agar gel precipitation
• Immunofluorescence
• Hemagglutination inhibition
• virus neutralization (also has PROTECTIVE effect)
• ELISA

Question 12

Maternal immunity in poultry

Answer 12

• protects during first few days of life
• IgY transferred to maturing oocyst in ovarian follicle and accumulates in yolk sac
• IgA and IgM also transferred through swallowing of amniotic fluid
• peaks at 2-3 days, persists 2-5 days