The major histocompatibility complex (MHC) is
a set of molecules displayed on cell surfaces that are
responsible for lymphocyte recognition and “antigen
presentation”. It is encoded by several genes located
on human chromosome 6. Major histocompatibility
complex (MHC) is also referred as the HLA (or Human
Leucocyte Antigen) system in humans.• Tissue matching, blood group matching are therefore
essential before undertaking any graft/transplant.
• Immunosuppressive drugs or immunosuppres-
sants are drugs, that are used in the immunosuppressive
therapy to inhibit or prevent activity or response of the
immune system during graft transplantation.Intext Practice Questions
- What are antigenic determinants?
- How do macrophages in the human body act as ‘HIV factory’?
- Why do most persons fall sick due to smallpox only once in their lifetime, and not
repeatedly? - How does vaccination against a disease provide protection against that disease?
10.What are the different ways to develop immunity? - Damage to thymus in a child may lead to
(a) a reduction in haemoglobin content of blood
(b) a reduction in stem cell production
(c) loss of antibody mediated immunity
(d) loss of cell mediated immunity. - Lysozyme that is present in perspiration, saliva and
tears, destroys
(a) certain types of bacteria
(b) all viruses
(c) most virus-infected cells
(d) certain fungi. - Which one of the following cells is not a phagocytic
cell?
(a) Macrophage (b) Monocyte
(c) Neutrophil (d) Basophil - If the person shows the production of interferons in
his body, chances are that he is suffering from
(a) measles (b) tetanus
(c) anthrax (d) malaria. - An example of innate immunity is
(a) PMNL - neutrophils (b) T-lymphocytes
(c) B-lymphocytes (d) TH cells. - The class of antibodies made up of five immunoglobulin
units is ___.
(a) IgG (b) IgM
(c) IgA (d) IgD - Each immunoglobin has two heavy chains and two
light chains, and the antigen binding site is present
in