Immunology Study Material and Solved Assignments

Access study material, solved assignments, essays, and dissertations on Immunology. Learn about cells, immune system receptors, antigen processing, T cell activation, cytokines, cancer immunotherapy, immune deficiencies, transplantation immunology, vaccines, and more.

Running head: IMMUNOLOGY
IMMUNOLOGY
Name of the Student
Name of the University
Author Note

1IMMUNOLOGY
Week 1
Cells are generally called as the building blocks of life. A group of cells together
forms tissue and tissue system. Now, the tissue system is accumulated to form a particular
organ. A group of organs, which function together to perform one or more physiological
actions called as organ system.
Immune system receptors, actually present on the cell membrane and binds to a
substance, like cytokines and give responses.
Cells involved in the natural or native immunity are skin and outer epithelial barrier
cells, scavenger cells, like neutrophils, mast cells, basophils, eosinophils, macrophages,
dendrite cells and natural killer cells. Also, cells involved in the specific immunity or
acquired immunity are B- Lymphocytes and T- Lymphocytes and effecters T-cells.
Week2
There are two types of receptors involved in recognition of antigen. One is B cell
receptors and another one is T cell receptors.
B cell receptors exclusively recognize unprocessed antigen binds to B cell receptors,
like protein, lipids, polysaccharides and nucleic acids.
T cell receptors recognizes processed peptides presented by major histocompatibility
complex ( MHC) molecule on the surface of other cells.

2IMMUNOLOGY
Week 3
Antigens are deteriorated into small antigenic peptides that form substances in
association with class I or class II MHC molecules. There are two types of antigen
processings. One is exogenous processing and other is endogenous processing.
Exogenous antigens are produced outside the cells. In case of exogenous processing
exogenous antigens are ingested by phagocytises or endocytosis and fragmented in to small
peptides by macrophages, dendrite cells and B cells. Now this degraded antigen fragments
bind to the cleft within the class II MHC molecules.
However, endogenous antigens are produced inside the host cells. In endogenous
pathway fragmented antigens bind with the class l MHC molecules. The peptide-class I MHC
complex is allowed to pass into the cell membrane. All cells producing endogenous toxin use
this route to process the antigen.
The main difference between the presentation of peptides by MHC class l and class ll
is that, class I MHC complexes are formed in case of exogenous pathway and class II MHC
complexes are formed in endogenous processing of antigen .
The machinery involved in the processing of antigens is antigen processing and
presenting machinery (APM).
The purpose of antigen processing is to recognition of antigen presenting cells by T
cell depending upon their expression of a spectrum of peptides combine to class I or Class II
MHC complexes.

3IMMUNOLOGY
Week 4
T cells get stimulated on identification of peptide-MHC complexes with T cell
receptors and become proliferated. Then T cells form clonal expantion and split into memory
cells and effecter T cells. It is used to recognition of antigens both in lymphoid organs and
peripheral non-lymphoid tissues. The promptness of T cells needs identification of antigens
shown over APCs. Its activation also requires cytokines manufactured by the APCs and by T
cells. Activation of native T cells need dendrite cells and macrophages or B cells.
However, both the signals are eventually important for highest activation of T cell
stimulation. Signal 1 is produced because of the interaction of TCR-CD3 complex with MHC
peptide. Signal 2 is propagated by the interaction of CD28 on the T cells and members of the
B7 family on the APC, which is also known as co-stimulatory signal.
Week 5
Cytokines are the large polypeptides or glycoproteins, which are secreted by
particular cells of immune system.
Cytokines are signalling molecules that regulate both immunity and inflammation.
Cytokines regulate proliferation, differentiation, and function of immune system cells.
Cytokine has very less molecular weight and it is secreted by white blood cells and other cells
in response to a number of stimuli. Cytokine combines with specific receptors present on the
membrane of target cells. Cytokines and cytokine receptors show very high bracing to each
other. A specific cytokine can attach to a particular receptor on the membrane of the same
cell that secreted it, which is termed as autocrine action. Sometimes binding occurs in nearer
vicinity to the producer cell, which is termed as paracrine action.

4IMMUNOLOGY
Th1-Th2 dichotomy- The immunology of pregnancy is a complex issue, here the
mother must tolerate the “foreign” foetus, and hence requires a degree of
immunosuppression. However, on the other hand it is necessary to maintain immune function
to destroy infection. The specific mechanism which is engaged in successful pregnancy
maintenance is the proposed switch from the T helper 1 (Th1) cytokine profile to the T helper
2 (Th2) profile. Therefore, maintaining the pregnancy and prevent the infection of the fetus
Th1-Th2 dichotomy is required.
Evolution strategies of pathogens to avoid host immune system- There is a way in
which a pathogen or an infectious agent may elude immune surveillance is by altering its
antigens. There are three ways by which antigenic variation can be performed.
The most common process is hiding from immune cells by change or shed antigens
and remain inaccessible to the host immune system.
Second method is resisting innate immune defences, like carbohydrate capsule resists
phagocytosis, replication within phagocytes, and inhibition to antimicrobial peptides.
The third one is the activating and interfering with signalling pathways and resist
antigen presentation.
Pathogens are overcome by the following four mechanisms.
First process is phagocyte signalling, which describes the binding of antibodies to
antigens on the surface of pathogens, that makes it easier for phagocytes to find the pathogens
and kill them.
Second process is associated with the antigen clumping.

5IMMUNOLOGY
The third process based on the prevention of cell entry by coating the surface of the
pathogens. As a result, pathogens are incapable of entering body cells. In the last method,
antibodies secret some complementary proteins, like perforin, that pokes holes in pathogen
membranes. It causes burst of the pathogen cells.
Immunotherapy is a type of therapeutic medication to prevent or treat certain disease
with substances that stimulate the immune response.
It can generally be applied to various disorders by boosting the immune system of the
body. Also help to instruct the body’s immune system to attack cancer cells specifically.
Sometimes man-made immune system proteins will be very helpful to fight against certain
pathogens.
Immunotherapy works by both passive and active therapies.
Passive immune-therapy are based on the administration of monoclonal antibodies
that aim either tumour-specific or over-expressed antigens.
On the other hand active immunotherapy are crucially controlled by cytokines, cancer
vaccines, cell-based therapies, tumour-specific CTL, tumour-derived APC and DC priming.
Week 6
Cancer is mainly developed by abnormal cell multiplication. It only happens by
damaged gene or activated oncogene , which is called mutation of genes. Mutation can be
happened by exposure to toxic chemicals, low dose radiation and infection with certain virus.
The main characteristics of the cancer cells is unrestrained proliferation, unnatural
nucleus, reduction of anchorage, chaotic multilayer, tumour or undifferentiated cell

6IMMUNOLOGY
mass production, undergoes metastasis and angiogenesis, lack of differentiation into
specialized cells and enhance the rate of anaerobic glycolysis.
Oncogenes are the genes that earlier was proto oncogenes. That means, proto-
oncogenes , when mutated may develop into oncogene. Oncogene are all those genes, which
produces certain proteins that will lastly result cancer to grow into the body of an individual.
Now oncogene when translated they will produce specific proteins known as onco-proteins.
This oncoproteins are required for developing cancer. Because, it induces the cell division
and proliferation pathway.
Secondly, it averts the cell death, which is known as apoptosis or program cell death.
Because of abnormal cell division the cell will manufacture a enormous mass of
undifferentiated cells, which will form tumour. Now, that tumour will generate new features
after every particular time gap, like angiogenesis feature, metastasis feature and slowly the
tumour will turn in to malignant tumour or cancer. As a result, the tumour will cause the
person to die.
There are some molecules or proteins that help in regulating whether the cell will
follow the living pathway or follow the death pathway. Those regulatory proteins are known
as tumour suppressor protein and the gene that encodes those protein are known as tumour
suppressor genes.
TATA- Major number of tumor particles are also present on our own cells and are considered
as tumor associated transplantation antigens (TATA). They are shown only during the growth
of cells and lost during mature phase of life however re-disclose in tumours.

7IMMUNOLOGY
Immunotherapy for cancer can be developed by cytokines. Cytokines generally act
as a molecular messenger that permit the cells of the immune system to impart with one
another to produce a strong, coordinated response to a specific antigen. Cytokines act by
stimulating immune effector cells and stromal cells of certain tumours directly. These
molecules also promote cancer cell recognition by cytotoxic effecter cells. In the present
years certain number of cytokines, including GM-CSF, IL-7, and IL-21, use in the clinical
trials for the patient having advanced type of cancer. In other hand IL-10 and TGF-beta
promote anti-tumour immunity. FDA gives achievement to IL-2 for metastatic melanoma and
renal carcinoma and IFN-alpha for adjuvant therapy of stage III melanoma.
Week 7
Some common immune-deficiencies are B cell deficiencies, T-cell deficiencies,
Phagocytise cell deficiencies and complement deficiencies. Among them B-cell and T-cell
deficiencies are the most severe type of deficiencies.
Immune deficiency can be treated either by transplantation of bone marrow, stem cell
and thymus or by replacement of immunoglobulin. Sometimes gene therapy and preventive
antibiotic strategies are highly beneficial in the management of specific immune defects.
Week 8
Transplantation immunology deals with removing injured tissues from one site to
another and is a form of organ transplantation. There is one side effect in this process, which
is rejection from the donor. This rejection is caused by the immune response, which fails to
recognize, ultimately leading to destruction of the transplanted organ.

8IMMUNOLOGY
Before the operation tests are considered like testing of blood groups and tissue type
to decrease the chances of rejection. Immunosuppressive drugs are administered to mediate
the risk of rejection. Immunosuppressive drug ensures dampening of immunity resistance.
Week 10
Traditional vaccines- Lived virus vaccines are mumps, measles, rubella and varicella
vaccine. Killed or inactivated vaccines, such as whooping cough vaccine. Toxoid vaccines,
like tetanus and diphtheria vaccine. Biosynthetic vaccines are Hepatitis B vaccine.
Vaccine induces effecter mechanism by which it rapidly controls the replication of
pathogens or inactivates their toxic component. Vaccine mainly acts by triggering of B and
T-cell responses. We can influence this by developing primary and secondary immunity.
Some of the newer types of vaccines are pneumococcal conjugate vaccine (PCV), rota
virus vaccine (RV) and haemophilias influenza type b (Hib) vaccine.
Week 11
Immunological bioinformatics- The combination of immunology and bioinformatics
is known as immunomics or computational immunology. Bioinformatics have been used to
reveal how MHC heterozygosis influences individual’s interaction with bacteria and the
influenza virus.
Also shows the process of the stress level of host to affect the pathogenicity of
pseudomonas aeruginosa in the gut of human. Immunomics again properly describes the
reason of lowering the value of the frequency of staphylococcal-induced toxic stress
response.

9IMMUNOLOGY
Week 12-
Mechanisms of allergic reaction can be described as follows:
Figure 1 : Mechanism of Allergy
Source: (https://link.springer.com/chapter/10.1007)
Allergy can be diagnosed by the measurement of the level of IgE antibodies in blood
by radio-allergosorbent test (RAST).
Also skin prick test and patch test are generally used to diagnose allergy.
The most effective treatments of allergy are medication and immunotherapy.

10IMMUNOLOGY
In the first case antihistamine, decongestants, leukotrine receptor antagonist and
steroid sprays are used in the treatment and management of an allergic reaction in the body.
SECTION B
1. There are four types of route of administration of vaccine. Those are oral
vaccination, intramuscular vaccination, subcutaneous vaccination and intradermal
vaccination.
Oral vaccination is given against OPV and Rotavirus. Intramuscular vaccine is
administered against Hepatitis B, IPV, Hib, diphtheria pertussis and tetanus (DPT) virus.
Subcutaneous vaccination is used for measles and yellow fever. Lastly, the intradermal
vaccination is given against BCG.
2. Co-stimulation is secondarily generated signal which the immune system cells
depend on to activate an immune response. In most of the immune responses, activation
needs the presence of a co stimulator. An antigen and a co stimulator are required to generate
the immune response, which ensures that healthy cells are not destroy.
4. The capability of recipient T cells to identify antigen from donor ( transplanted
organ) or donor MHC molecules directly or indirectly, known as allorecognition, begins
allograft rejection. Activated T -cells undergo clonal expansion and split into effector cells.
These cells then place into graft, where those cells initiate tissue damage. Also B cells and
anti-HLA antibodies play an major role in the acute allograft rejection.
Mycophenolate mofetil is used as an immunosuppressive agents in combination with
ciclosporin in transplantation surgery.

11IMMUNOLOGY
5. Dendrite cells convert antigens into immunogens for T cells. DCs act as catalysts
for triggering and controlling immunity. On the other hand, DCs are located in the body
where antigens gain access to body and maintain a vital role in the induction of antitumor
responses.
Figure 2: DCs mediated immunology
Source: (https://www.frontiersin.org/articles/10.3389)
6. Therapeutic antibodies are certain kind of proteins activated by the immune
responses through immune system and neutralize specific or non-specific foreign antigens.
These are two types : monoclonal and polyclonal antibodies.
Monoclonal antibodies are manufactured by a single clone of cells, examples:
abciximab, basiliximab, cetuximab and ipilimumab.
Whereas, polyclonal antibodies are produced by serum or B-lymphocytes by in-vivo
method, examples: S-100.
Another types of immunoglobulin are IgG, IgA, IgM, IgE, IgD. They all are
composed of two heavy chain and two light chain.