183
Jenner is therefore considered the father of experimental “immunology.” No
mechanistic explanations of that experiment were, however, possible at that time:
only about 100–150 years later we started discovering antibodies and immune system functions allowing us to understand what was biologically happening at that
time in the milkmaids (and at any other time in “immune” individuals) and in the
“vaccinated” individuals like Jenner’s gardener’s son.
All the developing “immunological” science, enriched later through microbiology, biochemistry, physiology and pathology studies in the following decades,
recorded more and more details in the functioning of the defense mechanisms of
mammals and humans, having the most complex and efficient forms of immunological defense against foreign agents entering the body.
The immune system is in fact like an “eye within” the body, controlling that
nothing extraneous is biologically active in each individual organism, and therefore,
recognizing effectively “self” from “not-self”, so that replication of self-cells are
not contaminated by “foreign” biological agents and that any extraneous biological
entity will be eliminated by soluble “light” weapons (antibodies) and by “heavy”
killers (immune cells and macrophages, interacting and collaborating in the task).
The key steps of an immune reaction are substantially three: (a) internalization of
foreign particles by macrophages (MPH) degrading and “presenting” them to
T-helper lymphocytes (T h -cells) which in turn start an elaborated attack, mostly
through either (b) synthesis of soluble “light” weapons (antibodies, humoral
response by B-cells) or (c) development of cellular “heavy” weapons (killer
T-lymphocytes T-K cells, with cellular or cytotoxic response); in many cases, we
observe the activation of both responses (b + c), depending on the needs. The key
steps of an immune reaction are illustrated in the following Fig. 11.1.
Recently, it has been shown that activated T-cells tend to aggregate, like a swarm
of bees, exchanging information, useful to coordinate the immune response (i.e., to
elaborate coordinated defense plans): this is the visual demonstration of the complex molecular dialogue taking place within the various families of immune cells
collaborating to the full enactment of defense mechanisms.
When invaders are present in body fluids or the extracellular domains, like most
bacteria, they can be attacked by antibodies, through specific surface recognition.
However, when the invaders are instead of the intracellular type, like viruses and
some bacteria (like TBC), they must instead be attacked by special killer lymphocytes (cytotoxic TK-cells), which destroy all the self-cells harboring the intruders,
together with their content. Nevertheless, viruses anyway can also transit the body
fluids; consequently, also antibodies are produced against them.
In most responses, both humoral (antibodies) and cellular attacks are deployed.
The immune response, moreover, is specific and potentiated by memory: therefore,
a second (or further) encounter with the same foreign agent (antigen) produces a
stronger and quicker defense reaction. Details of the immune mechanisms are continuously discovered. So, this discipline is still far from being completely described
and understood. New details are continuously added and better focused by immunology researchers in time [16].
11 Defense Against Biological Terrorism: Vaccines and Their Characterizations
Jenner is therefore considered the father of experimental “immunology.” No
mechanistic explanations of that experiment were, however, possible at that time:
only about 100–150 years later we started discovering antibodies and immune system functions allowing us to understand what was biologically happening at that
time in the milkmaids (and at any other time in “immune” individuals) and in the
“vaccinated” individuals like Jenner’s gardener’s son.
All the developing “immunological” science, enriched later through microbiology, biochemistry, physiology and pathology studies in the following decades,
recorded more and more details in the functioning of the defense mechanisms of
mammals and humans, having the most complex and efficient forms of immunological defense against foreign agents entering the body.
The immune system is in fact like an “eye within” the body, controlling that
nothing extraneous is biologically active in each individual organism, and therefore,
recognizing effectively “self” from “not-self”, so that replication of self-cells are
not contaminated by “foreign” biological agents and that any extraneous biological
entity will be eliminated by soluble “light” weapons (antibodies) and by “heavy”
killers (immune cells and macrophages, interacting and collaborating in the task).
The key steps of an immune reaction are substantially three: (a) internalization of
foreign particles by macrophages (MPH) degrading and “presenting” them to
T-helper lymphocytes (T h -cells) which in turn start an elaborated attack, mostly
through either (b) synthesis of soluble “light” weapons (antibodies, humoral
response by B-cells) or (c) development of cellular “heavy” weapons (killer
T-lymphocytes T-K cells, with cellular or cytotoxic response); in many cases, we
observe the activation of both responses (b + c), depending on the needs. The key
steps of an immune reaction are illustrated in the following Fig. 11.1.
Recently, it has been shown that activated T-cells tend to aggregate, like a swarm
of bees, exchanging information, useful to coordinate the immune response (i.e., to
elaborate coordinated defense plans): this is the visual demonstration of the complex molecular dialogue taking place within the various families of immune cells
collaborating to the full enactment of defense mechanisms.
When invaders are present in body fluids or the extracellular domains, like most
bacteria, they can be attacked by antibodies, through specific surface recognition.
However, when the invaders are instead of the intracellular type, like viruses and
some bacteria (like TBC), they must instead be attacked by special killer lymphocytes (cytotoxic TK-cells), which destroy all the self-cells harboring the intruders,
together with their content. Nevertheless, viruses anyway can also transit the body
fluids; consequently, also antibodies are produced against them.
In most responses, both humoral (antibodies) and cellular attacks are deployed.
The immune response, moreover, is specific and potentiated by memory: therefore,
a second (or further) encounter with the same foreign agent (antigen) produces a
stronger and quicker defense reaction. Details of the immune mechanisms are continuously discovered. So, this discipline is still far from being completely described
and understood. New details are continuously added and better focused by immunology researchers in time [16].
11 Defense Against Biological Terrorism: Vaccines and Their Characterizations