1. OVERVIEW (part 3):
adaptive immunity & cells of
the immune system
Marilen M. Parungao-Balolong
BIO 151 Lecture 3
2nd SEM 2010-2011
Reference: Kuby & Roitt and Roitt
2. WHATYOU NEED TO
KNOW
⢠Characteristic Attributes of Adaptive Response
⢠Lymphocytes as KEY players
⢠Humoral ImmunityVersus Cell-Mediated Immunity
⢠Antigen Recognition
⢠Clonal Selection
⢠Integration: Innate & Adaptive Response
⢠Cells of the Immune System (Innate and Adaptive)
3. ADAPTIVE IMMUNITY
⢠capable of recognizing and
SELECTIVELY eliminating
SPECIFIC foreign
microorganisms and molecules
⢠not the same in all members of
species
⢠reactions to speciďŹc antigenic
challenges
5. ANTIGENIC
SPECIFICITY
⢠permits it to distinguish even SUBTLE
differences among antigens
⢠Example:Antibodies can distinguish
between two protein molecules that
differ in only a SINGLE amino acid
7. IMMUNOLOGIC
MEMORY
⢠exhibited once the immune system has
recognized and responded to an antigen
⢠THUS, the second encounter induces a
HEIGHTENED state of immune reactivity
⢠can confer life-long immunity against
many infectious agents after an initial
encounter (BASIS for vaccination)
9. THE LYMPHOCYTES
⢠An effective immune response involves two major groups of cells: T
lymphocytes and antigen-presenting cells
⢠Lymphocytes are one of many types of white blood cells produced
in the bone marrow by the process of hematopoiesis (TO BE
DISCUSSED LATER)
⢠Lymphocytes leave the bone marrow, circulate in the blood and
lymphatic systems, and reside in various lymphoid organs
⢠Because they produce and display antigen-binding cell-surface
receptors, lymphocytes mediate the deďŹning immunologic attributes
of speciďŹcity, diversity, memory,and self/non-self recognition
⢠The two major populations of lymphocytesâB lymphocytes (B
cells)and T lymphocytes (T cells)âTO BE DISCUSSED IN DETAIL
11. HUMORAL & CELL-
MEDIATED IMMUNITY
⢠HUMORAL: immunity that can be conferred upon
a non-immune individual by administration of
serum antibodies from an immune individual
⢠CELL-MEDIATED: can be transferred only by
administration of T-cells from an immune individual
17. INTEGRATION:
INNATE & ADAPTIVE
RESPONSE
⢠Adaptive immune system produces signals and components that stimulate and
increase the effectiveness of innate response
⢠Major difference: rapidity of the innate immune response,which utilizes a pre-
existing but limited repertoire of responding components
⢠Adaptive immunity compensates for its slower onset by its ability to recognize a
much wider repertoire of foreign substances,and also by its ability to improve
during a response,whereas innate immunity remains constant
⢠Secondary adaptive responses are considerably faster than primary responses
⢠Overlapping roles: two systems together form a highly effective barrier to
infection
18.
19. INTEGRATION
Although the innate mechanisms do not improve with repeated exposure to infection as do
the acquired, they play a vital role since they are intimately linked to the acquired systems
by two different pathways which all but encapsulate the whole of immunology. Antibody,
complement and polymorphs give protection against most extracellular organisms, while T-
cells, soluble cytokines, macrophages and NK cells deal with intracellular infections
20. NICE TO KNOW
â˘While an adaptive immune system is found only in
vertebrates, innate immunity has been demonstrated in
organisms as different as insects,earthworms,and higher
plants
â˘Dysfunctions of the immune system include common
maladies such as allergy or asthma
â˘Loss of immune function leaves the host susceptible to
infection;
â˘in autoimmunity,the immune system attacks host cells
or tissues
21. CELLS OF THE IMMUNE SYSTEM
â˘Hematopoiesis
â˘Stem Cells
â˘Apoptosis or
Programmed Cell
Death: induced and
ordered process in
which the cell
actively participates
in bringing about its
own demise = a
critical factor in the
homeostatic
regulation
