B7. Immune Response to Parasites

Question 1

Complexity of parasite atg

Answer 1

• Different stages of development with different atg structure in the same host
• Different parasite species in the same host at the same time
• Differences in the intensity of the infection
• Change sin the immune response of the animal according to the evasion strategies of the parasite

The immune reactions against the parasitic infection can be direct and target oriented, e.g. ADCC reaction of protozoa. It can also be indirect, e.g. in enteroallergic reactions against intestinal worms.

Question 2

Defense of the parasite can be

Answer 2

• Decreasing the response of the host by immune tolerance induction or weakening of the hosts effector functions (gestation, lactation).
• The parasite also has different evasion mechanisms: o Atg variability
o Hypoantigenicity o Antigen mimicry MHC or blood group (like atg)
o Barrier production o Binding of hosts tags
• Suppression of the host immune defines can also occur, B cell exhaustion, I.S materials and Ts activation. • Clinical signs will appear if the number of parasites are too high, not in their natural host or if the host have immune deficiencies.

Question 3

Natural resistance of the host

Answer 3

• Genetics, age and hormone dependent resistance - Hygiene!!!
• Natural host
• Genetic resistance (Malaria and sickle cell anaemia, where Val instead of Glut in Hb —> toxic to Malaria. Heterozygotes survive.)

Question 4

Specific protection

Answer 4

• Humoral: opsonisation, agglutination, immobilisation, enzyme inactivation, IgE (Type I hypersensitivity), complement activation, ADCC.
• Cellular response towards IC parasites involve: Tc, NK, ADCC.