Basic
Immunology
Second year
Laboratory medicine
,
, Introduction to immunology
Immunology:
Immunology is the science that studies the mechanisms by which human
body defends itself from foreign substances present in the environment. It is
divided into three major parts:
1. Basic immunology.
2. Diagnostic immunology.
3. Clinical immunology.
Part I-Basic immunology
History:
Immunity is derived from the Latin word immunitas and was referred to the
exemption or protection of Romans senators from various customs duties,
legal laws and legal prosecution. The word is then used in medicine to refer
to the protection of the body from microbes. The cells and molecules that
protect body from microbes constitute the immune system. The
collective and coordinated reaction between the immune cells and molecules
to get rid of microbes is termed the immune response.
Historically, immunity meant protection from infectious diseases. Later on,
scientists found that immune system protects the body not only from
infectious agents but also from foreign macromolecules (such as proteins
and polysaccharides) and from abnormal cells (such as tumor cells,
senescent cells and foreign cells).
Page 1
, They also found that in some individuals, the immune response that protects
the body causes tissue injury (either local or systemic injury).
Immunity:
Immunity is the protection of the body from foreign substances such as
microbes (bacteria, viruses, fungi, and protozoa), macromolecules (proteins,
peptides, and polysaccharides), foreign and abnormal cells without causing
any tissue injury to the host.
Types of immunity:
1) Innate immunity: It is the first line of defense against an antigen.
2) Adaptive immunity: It is the second line of defense.
Although these two arms of the immune system have distinct functions, both
innate and adaptive immunity interact at several levels to develop a complete
defense against foreign substances. In other words, the components of innate
immunity influence the adaptive immunity and vice versa.
Innate immunity (native, non-specific, natural)
Innate immunity refers to resistance which is present in all normal
individuals from birth, and once activated the same mechanisms occur
regardless of which foreign substance or previous exposure to the same
antigen.
Innate immunity provides immediate defense. It has a limited capacity to
distinguish one microbe from another or the types of foreign
macromolecules. It lacks immunological memory, i.e. it is unable to
remember. It involves the same mechanisms every time the same antigen
entered the body. Innate immunity not only provides rapid defense against
Page 2
Immunology
Second year
Laboratory medicine
,
, Introduction to immunology
Immunology:
Immunology is the science that studies the mechanisms by which human
body defends itself from foreign substances present in the environment. It is
divided into three major parts:
1. Basic immunology.
2. Diagnostic immunology.
3. Clinical immunology.
Part I-Basic immunology
History:
Immunity is derived from the Latin word immunitas and was referred to the
exemption or protection of Romans senators from various customs duties,
legal laws and legal prosecution. The word is then used in medicine to refer
to the protection of the body from microbes. The cells and molecules that
protect body from microbes constitute the immune system. The
collective and coordinated reaction between the immune cells and molecules
to get rid of microbes is termed the immune response.
Historically, immunity meant protection from infectious diseases. Later on,
scientists found that immune system protects the body not only from
infectious agents but also from foreign macromolecules (such as proteins
and polysaccharides) and from abnormal cells (such as tumor cells,
senescent cells and foreign cells).
Page 1
, They also found that in some individuals, the immune response that protects
the body causes tissue injury (either local or systemic injury).
Immunity:
Immunity is the protection of the body from foreign substances such as
microbes (bacteria, viruses, fungi, and protozoa), macromolecules (proteins,
peptides, and polysaccharides), foreign and abnormal cells without causing
any tissue injury to the host.
Types of immunity:
1) Innate immunity: It is the first line of defense against an antigen.
2) Adaptive immunity: It is the second line of defense.
Although these two arms of the immune system have distinct functions, both
innate and adaptive immunity interact at several levels to develop a complete
defense against foreign substances. In other words, the components of innate
immunity influence the adaptive immunity and vice versa.
Innate immunity (native, non-specific, natural)
Innate immunity refers to resistance which is present in all normal
individuals from birth, and once activated the same mechanisms occur
regardless of which foreign substance or previous exposure to the same
antigen.
Innate immunity provides immediate defense. It has a limited capacity to
distinguish one microbe from another or the types of foreign
macromolecules. It lacks immunological memory, i.e. it is unable to
remember. It involves the same mechanisms every time the same antigen
entered the body. Innate immunity not only provides rapid defense against
Page 2
