Introduction to Immunology Cheat Sheet
Key Immunology Terms Immune System:
It is a unique adaptive defensive system that has
evolved in vertebrates to protect them from invading
pathogenic microorganisms and cancer. Immunity: All
those physiological mechanisms that endow the
animal with the capacity to recognize materials as
foreign to itself and to neutralize, eliminate or
metabolize them with or without injury to its own
tissues. Antigen: Any substance (usually foreign) that
bind specifically to an antibody or a T cell receptor.
Antibody: A protein (immunoglobulin) that recognizes
a particular antigen and binds specifically to it. Innate
immunity or native immunity: It is the resistance to
infections which an individual possesses by virtue of
his genetic and constitutional make-up. It is not
affected by prior contact with microorganisms or
immunization. Adaptive immunity or acquired
immunity: It is the resistance that an individual
acquires during life, as distinct from the inborn innate
immunity. Adaptive immune responses exhibit four
immunological attributes: Specificity, Diversity,
Memory, Self and non-self recognition.
Immune System
Vertebrates have a unique adaptive Immune System
that has evolved to protect them from invading
pathogenic encounters. We are able to fight against
the infectious agents, because of the presence of
effective, protective and complex array of Immune
System. Protection against infectious diseases is only
one of the consequences of the immune response,
which in its entirety is concerned with the reaction of
the body against any foreign antigen. The immune
system is composed of many interdependent cell
types, organs, and tissues that jointly protect the
body from infections. The immune system comprises
of two parallel but interrelated systems: The Humoral
immune response and Cellular immune response.
Humoral and Cellular Immunity
In the humoral immune response, antibodies function
as recognition elements and binds specifically to
antigens. In the Cellular immune response cytotoxic
T-lymphocytes kill cells that display foreign motifs on
their surfaces. The cellular immune response is
mediated by specific receptors that are expressed on
the surface of the T cells.
Cells and Organs of Immune System
Immune responses are mediated by variety of cells
and by the soluble molecules, which they secrete.
Leucocytes (WBCs) are central to all immune
responses. The organs and tissues involved in
immune response can be divided as Primary
lymphoid organs: Thymus and Bone marrow.
Secondary lymphoid organs: Lymph nodes, spleen, &
mucosal associated lymphoid tissue (MALT).
Antigen and Antibody
An Antigen (usually foreign) is a substance that binds
specifically to an antibody. Antibody is a protein
(immunoglobulin) that recognizes a particular antigen
and binds specifically to it.
Innate and Adaptive Immunity
Immune system comprises two parallel but
interrelated systems, known as Innate Immunity and
Adaptive immunity. Innate immunity is the resistance
to infections which an individual possesses by virtue
of his genetic and constitutional make-up and
includes anatomic, physiologic, endocytic and
phagocytic and inflammatory barriers that help
prevent the entrance and establishment of infectious
agents. Adaptive immunity is the resistance that an
individual acquires during life. Adaptive immune
responses exhibit four immunological attributes:
Specificity, Diversity, Memory, Self & Non-self
recognition. Antigen presenting cells, Blymphocytes
and T- lymphocytes are the primary cells of the
adaptive immune responses. It is of two types, active
and passive.
History of Immunology
The history of immunology can be traced back to 430
BC. Chinese and Turks developed the technique of
Variolation. Edward Jenner, ‘father of vaccine’,
improved the technique of Variolation and his
experiments on smallpox turned to be breakthrough
finding in the field of immunology. In 1885, Pasteur
administered the first vaccine to a human, a young
boy, Joseph Meister, bitten by rabid dog. He also
developed the vaccines for anthrax and cholera.
Robert Koch, Elie Metchnikoff, Emil von Behring and
Shibasaburo Kitasato are the major contributors in
the development of immunology. The history of
Immunology can be traced back to 430 BC. This
subject has fetched 16 Nobel Prizes.
