Unit 3rd biotechnology Bachelor of Pharmacy PCI

1. Immunity
Immunity is the ability of human body to resist almost all kinds of
organisms and toxins that tends to damage the tissues and organs.
→ Fungi, Protozoans, Bacteria and viruses are all potential pathogens.
Immune Response - reaction of the cells and fluids of the body to
the presence of a substance which is not recognized as a constituent
of the body itself.

2. 1. Pre-immune mechanisms
Ag penetrates tissues (vasodilatation, edema)
Adsorption of the Ag to immune tissue
2. Immune mechanisms
migration of APCs in T-or B-zone peripheral organs of the immune system
Processing of Ag: Stage 1 – Endocytosis of Ag
Stage 2 - cleavage (processing)
Stage 3 - expression of degraded particles Ag at the MTC in complex
with MHC I or MHC II
Stage 4 – presenting to TH
3. Suppression of the immune response (Autoimmune diseases can run)
4. Immunological memory
Mechanism of IR

4. Goal: to stop pathogens from entering the body
→ Skin –
acts as a
barrier to
invasion
→ Sweat –
has
chemicals
which can
kill
different
pathogens.
→ Tears -
have
lysozyme
which has
powerful
digestive
abilities that
render
antigens
harmless.
→ Saliva
– also has
lysozyme.
→ Mucus -
can trap
pathogens,
which are
then
sneezed,
coughed,
washed
away, or
destroyed by
chemicals.
→ Stomach
Acid –
destroys
pathogens
First line of defense

6. If a pathogen is able to get past the body's first line of defense, and
an infection starts, the body can rely on it's second line of defense.
→ First there is a non-specific response (phagocytosis) followed by
an INFLAMMATORY RESPONSE.
Second line of defense
Phagocytosis = ingestion + digestion of pathogens.

9. →In process of developing of CI
phagocytic cells involved in the
expulsion of pathogens from the
intercellular space.
→Phagocytic cells attack
pathogens and destroy them. On
intracellular level macrophages are
the main cell protectors which
have specific receptors - Ig,
through which they effect on the
pathogen.
→Its aim is to combine phagocytosis and
specific antibodies to fight pathogenic
environment.
Cellular Immunity

11. → T-lymphocytes
→ Macrophages
→ NK-cells (type of CTL)
Cells involved in CI
* Macrophages
present antigen via
their surface MHC
to T-cells
* T-cells recognize
antigen through
their specific
receptors (TCR)
* A specific T-cell
clone becomes
activated and
begins to
proliferate
* Activated TH
lymphocytes
becomes effectors
cells that secrete
cytokines

12. → Protein Pathogen processed and converted into peptide to
bind a MHC molecules on APC to be presented on T-cell
AG Processing and presentation

13. 5. Stimulate B-cells to differentiate into plasma cells that secret antibodies
4. They activate NK cells increasing their cytotoxic functions
3. Promote activity of CD8 CTLs which directly kill virus infected cells, tumour cells, and graft rejection
2. Activate macrophages to kill intracellular microbes
1. Attract monocytes, macrophages and lymphocytes to the site
Cytokines stimulate other effectors cells of CMI and humoral immune response and mediate the following:

14. Sometimes the
second line of
defense is still
not enough and
the pathogen is
then heading for
the body's last
line of defense.
The immune system
recognizes, attacks,
destroys, and
remembers each
pathogen that
enters the body. It
does this by making
specialized cells
and antibodies that
render the
pathogens
harmless.
For each type of
pathogen, the
immune system
produces cells
that are specific
for that particular
pathogen.
Third line of defense

15. →The humoral response is carried out by antibodies which are produced by
Plasma cells.
→Plasma cells are derived from activated B-cells that are produced in the bone
marrow.
→Humoral immunity promotes the development of normal operation antibodies.
→The aim of bacteria and viruses (pathogens) – is to enter the cell to destroy it
→The principle of action of antibodies is the interruption of receptor linkages
between the pathogen and the cell.
→The result is to breakdown of interaction between pathogen and cells due to
blocking it by the effector molecule or antibody.
Humoral Immunity

16. Antibodies
An antibody (Ab) is a protein produced by B cells that is used by the immune
system to identify and neutralize foreign objects such as bacteria and viruses.
→ AB-dependent cell-mediated cytotoxicity: Ab attached to target cells cause destruction by
non-specific immune cells
→ Inflammation: Disruption of cells by complement/C-reactive protein attracts phagocytic
and other defensive immune system cells
→ Activation of complement
→ Neutralization: blocks adhesion of bacteria and viruses to mucosa. Also blocks active site
of toxin
→ Opsonization: Coating antigen with antibody enhances phagocytosis
→ Agglutination: Enhances phagocytosis and reduces number of infectious units to be dealt
with

17. Function
of
Antibodies

22. *
Monomer
→ The most common, represents 75-80% of serum Ig.
→ The only antibody capable of crossing the placenta
give passive immunity to the fetus.
→ Has longest half-life (23 days) among of all Igs.
→ Activates complement
→ Stimulates chemotaxis
→ Antigen receptor on surface B cells (together
with IgM).
→ Activate basophils and mast cells to produce
antimicrobial factors.
→ Bound to surface of mast cells and basophils
→ Destroys parasitic worms and participates in allerg
IgG
IgD
IgE
SS-bond

23. *
→ Present in body secretions
→ Provides protection against proliferation
of
microorganisms in this fluid
→ Aids in defense against microbes and
foreign
molecules penetrating body via cell linings
of
these cavities.
→ Provides passive immunity to infants
through
mothers breast milk
Dimer (trimer)
IgA

24. *
Pentamer
→ First Ig class produced in a primary
response to an Ag
→ Found on surface on B cells (together with
IgD)
→ Ag receptor of B cells
→ Has 10 antigen-binding sites
→ More effective at stimulating complement
→The FC receptors on phagocytes bind IgM
(opsonization)
IgM

25. → TH-cell then activates
an appropriate B cell by
releasing IL-2 to it.
Humoral Immunity
*IL-2 – growth factor for T and B cells

26. → The interaction between
the TH-cell and the B-cell
causes the B- cell to
differentiate into Plasma
cells and memory cells.
Humoral Immunity

27. Memory Cells
Memory T Cell
→ an infection fighting cell
Memory B cell
→ an antibody producing cell
Memory cells do not react right away but are held in reserve for later infections.
The secondary response that is carried out by memory cells is different in 3 ways.
→ Memory cells produce antibodies that bind with greater affinity
to their antigens than the antibodies produced in the initial response.
→ The response time is much vaster than the primary response
→ A greater number of antibodies are produced.

29. Lymphicytos – organism fighting infection
Proteins CD4 CD8 indexes shows the
condition of CI
State of secondary immunodeficiency
Rheumatic process
17.12.2013