Immunology

Question 1

Species immunity

Answer 1

Mice are extremely susceptible to infection by Streptococcus pneumoniae .Humans on the other hand are relatively resistant.
The rat is strongly resistant to diphtheria while guinea pigs and humans not
All humans are unsuscetible to plant pathogens and many animal pathogens such as rinderplast and distemper

Question 2

Racial Immunity

Answer 2

It is genetic in origin and by selection and inbreeding
-High resistance of Algerian sheep to anthrax
-Susceptibility to tuberculosis: people of Negroid origin In USA are more susceptible than Caucasians tto tuberculosis.
-Genetic resistance to plasmodium falciparum malaria:some parts of Africa and Mediterranean coast have sickled RBC

Question 3

Factors influencing the level of immunity

Answer 3

1)Age:
a) Foetus in Utero:immaturity
of the immune system
b)Newborn animals: more
susceptible to experimental
infections than adult animals
Eg. Coxaskievirus causes fatal
infection in suckling mice but
not adult mice
c)In elderly
2)Harmonal influences and sex
a)Endocrine disorders
b)Sex
3)Nutrition:
4)Stress

Question 4

Bacterial Vaccines

Answer 4

Live - BCG vaccine for
tuberculosis
Killed- Cholera vaccine
Subunit-Typhoid Vi-antigen
Bacterial products-Tetanus
toxoid

Question 5

Viral Vaccines

Answer 5

1)Live :
-Oral polio vaccine-Sabin
-17D vaccine for yellow fever
-MMR vaccine for
measles,mumps l,rubella
2)Killed
-Injectable polio vaccine-Salk
-Neural and non neural vaccines for rabies
-Hepatitis B vaccine
3)Subunit-Hepatitis B vaccine

Question 6

Types of immunoglobulin preparations

Answer 6

a)Human normal
immunoglobulin: temporary
protection against hepatitis A ,
prevent measles , protects
those with
agammaglobulinemia
b)Specific (Hyperimmune )
immunoglobulin:
Human tetanus (HTIG)
Hepatitis B (HBIG)
Human Rabies (HRIG)
Vearicella zoster (ZIG)
Antivaccina(AVIG)
b)Non Human (antisera)

Question 7

Sequestrated antigen

Answer 7

The antigen which is located in a closed system and is not accessible to the immune system.
1)Lens protein
2)Sperm

Question 8

Heterogenetic {Heterophile} Antigens

Answer 8

1)Forssman antigen:
2)Weil-Felix reaction:
3)Paul-Bunnel test:
4)Cold agglutinin test: by sera of primary atypical pneumonia
5)Agglutination of Streptococcus MG: by sera of the patients of primary atypical pneumonia

Question 9

Tolerogens

Answer 9

An antigen that induce tolerance is referred to as tolerogen.
Tolerance types :
a)Natural tolerance
b)Acquired tolerance

Question 10

Biological classes of antigens

Answer 10

1)T Cell independent (TI): Lipopolysaccharide of the gram negative organisms or pneumococcal polysaccharide of various species of S.pneumoniae .The immune response generated to these antigens tend to be similar on exposure i.e. IgM is the antibody and the response shows little memory.
2)T Cell dependent antigens (TD):They induce the full gamut of the immunoglobulin isotypes

Question 11

Superantugen

Answer 11

They provoke drastic immune response
1) Staphylococcal enterotoxins
2) Association with diseases

Question 12

Secretory component of IgA

Answer 12

Contain another glycine rich polypeptide called secretory piece or secretory component (a part of poly Ig receptor that remain attached to the IgA)