immune system acts as a defence mechanism to human body, constantly defending
it from invaders. When it is challenged by for example, a bacterial infection,
it increases the activity of some components which act to eliminate the source.
The immune system consists of two divisions: the innate and the acquired.
Factors such as genetics, gender, age, nutrient status, and gut flora
contribute to the variations in many immune functions. Every individual has a
varied immune function (Abbas et al.
immunity provides a first line of defence against infectious agents. It is
present before exposure to pathogens and has no memory, therefore is not
influences by prior exposure to an organism. It eliminates invading pathogens
through phagocytic cells and natural killer cells. The acquired immune response
involves very specific lymphocytes, and antibodies that are specific for an
individual antigen. It becomes effective after a couple of days after the
initial activation. It develops immunological memory that is the basis for a
stronger and more effective immune response on re-exposure to an antigen (Calder 2007).
is widely known that the interaction of microorganisms with the host immune
system is required for a healthy body. The microbiome – ecological community of
commensal, symbiotic, and pathogenic microorganisms – enriches the metabolism
and synthesis of many essential compounds and nutrients in human body.
immune system is shaped by microorganisms and many developmental aspects of the
adaptive immune system are influenced by the composition of bacterial
colonization of the gut. Intestinal microbiota plays a main role in the
metabolic, nutritional, physiological, and immunological processes of the human
body (Thomas et al. 2017).
Individuals with defective immune
responses are more prone to infections and more likely to suffer from
infectious morbidity and mortality. Individuals with immune function within the
“normal” range may not benefit from increased immune function of just 1
components but a sufficiently large change in some immune functions may improve
host defence (Corthesy et al. 2007).
This research would focus on
individuals with defective immune responses found in patients. Immunodeficiency
is a state in which the immune system’s ability to fight infectious disease is
compromised. Most cases of immunodeficiency are caused by extrinsic factors
such as HIV infection, cancer, chronic infections, and other environmental and
lifestyle factors. Clinical treatments sometimes suppress the immune functions
by either adverse or intended effect. This makes patients particularly
vulnerable to infections that would normally not cause any harm to a healthy
individual, and these are called opportunistic infections. In that state the
immune system struggles to fight against pathogens and is unable to protect the
body from invasion. The decreased ability of the immune system to clear
infections may be responsible for causing autoimmunity in patients (Grammatikos
and Tsokos 2012).
This research would test changes in
the immune response after injecting the host with bacteria that is naturally
occurring in a healthy individual. The results would help with the research and
development of immunotherapies. Patients could benefit from a quicker recovery
and a better protection from infections. It could also provide a better
understanding of the connection between immune response and extrinsic
modulation, in this case the gut flora. Analysing the effect of extrinsic
modulators of systemic metabolism on immune parameters can offer a better
understanding on how immune functions adapt to systemic metabolic change
(Giuseppe Danilo et al. 2015).
of various leukocyte numbers in the bloodstream can be used for assessments of
the immune system. This can be done by immunological staining procedures and
associated analytical techniques such as flow cytometry (Meydani et al. 1991).
variation of gut flora has no effect on the immune parameters and does not
increase the number of antibodies released after a vaccine strain is given.
Aims and objectives
aim is to test the effect of extrinsic modulator of systemic metabolism, the
gut flora, on the immune parameters. The aim is to see a positive relationship
between the bacteria found in the gut flora and the antibodies in the
Materials & methods
experiment would include three groups of laboratory mice. One group is the
control that will not be injected with any bacteria. Second group will receive
one dose of strains of bacteria and the third group will receive two doses with
an interval of one day between the first and second dose. All groups of mice
will then be challenged with a vaccine strain of yellow fever virus (YFV-17D)
and the number of antibodies in the bloodstream will be counted using flow
strains of bacteria used to inject into mice will include: Streptococcus faecium, Lactobacillus plantarum, Lactobacillus
rhamnosus, Propionibacterium freudenreichii, Bifidobacterium breve, Lactobacillus
reuteri, Lactobacillus salivarium, Bifidobacterium infantis, Streptococcus
thermophilus (Ford et al.
are easy to breed and economical to house in animal facilities. The use of
genetically inbred strains reduces variability. The SPF – specific
pathogen-free – husbandry enables microbial exposures to be controlled, further
reducing variability (Tao and Reese
mice lack differentiated memory T cells. Feral and pet store mice have many
more differentiated memory T cells in lymphoid and nonlymphoid tissue, similar
to adult humans. Mice with diverse environmental exposures have more mature
immune responses, similar to human adults. Whereas laboratory mice have
immature immune systems that can more easily be controlled (Tan et al. 2016).
data will indicate whether the diverse microbial exposure the adaptive immune
pathways, and possibly matures immune responses (Fourie et al. 2017).
the physical response to administration of antigen by measuring the changes in
concentration of antibodies in the bloodstream. The absolute response measured
might be different at different time points because the responses being
measured are dynamic in nature. The responses are related to the concentration
of the stimulant used to trigger the response (Calder 2007).
responses are very useful because they represent a coordinated, integrated
immune response to a relevant challenge (Tao
and Reese 2017).
studies would be limited by the ability to sample only blood and external secretions
such as saliva (Calder 2007).
Mice and their environment can be
controlled, however the use of animals in experimental research has to be ethical
(Anon. 2016). This research would not use any inhumane treatment or procedures
on the mice.
research can help to understand how immune parameters are altered through the
use of extrinsic modulators. This can help in other fields of research such as
immunotherapy and immunogenetics.
immune system also plays a crucial role in tissue repair and its potential dysregulation
(Laurent et al. 2017).
immune system plays an important role in the identification and elimination of
tumour cells and in the response to injury and trauma (Thomas et al. 2017).