ACQUIRED IMMUNITY.pdf

PG AND RESEARCH DEPARTMENT OF MICROBIOLOGY,SRI PARAMAKALYANI COLLEGE,ALWARKURICHI-627 412

1. SRI PARAMAKALYANI COLLEGE
( Reaccredited with B Grade with a CGPA of 2.71 in the II Cycle by NAAC
Affiliated to ManonmaniamSundaranarUniversity, Tirunelveli)
ALWARKURICHI 627 412 TAMIL NADU, INDIA
POST GRADUATE & RESEARCH CENTRE -DEPARTMENT OF
MICROBIOLOGY
(Government Aided)
IISEM -CORE –IMMUNOLOGY
Subject code ZMBM22
UNIT –1
ACQUIRED IMMUNITY
H. Ahamed Samsun
Fahmitha
REG NO: 20211232516101
I M.SC.MICROBIOLOGY
Sri Paramakalyani Colloge
Submitted to,
Dr. S. Viswanathan Ph.D,
ASSISTANT PROFESSOR,
SRI PARAMAKALYANI COLLEGE,
ALWARKURICHI.

2. OBJECTIVES –ACQUIRED IMMUNITY
To understand the importance of acquired immune system in controlling
pathogens
To understand the function of Various kind of T Cells
Compare the humoral and cell mediated immunity

3. SYNOPSIS
Acquired Immunity
Features of Acquired Immunity
Types of Acquired Immunity
1.Active Immunity
2.Passive Immunity
Difference between Active and Passive Immunity
Classification of Immunity
Components of Acquired Immunity

4. Acquired Immunity

5. Acquired Immunity
Immunity which is developed later in life after microbial infection in host is
called as Acquired or developed immunity.
The ability of the immune system to adapt itself to disease and to generate
pathogen-specific immunity is termed as acquired immunity. It is also known
as adaptive immunity.
Acquired immunity is a specific type of immune response that is elicited
based on the previous exposure of a host to a particular pathogenic
microorganism or antigen.

6. Features of Adaptive Immunity:
This immunity displays several characteristic attributes like:
(1) Specificity,
(2) Diversity,
(3) Immunologic memory,
(4) Discrimination between self and non-self

7. (1) Specificity:
This property of immune system permits it to distinguish among different and
even closely related molecules. Antibody, an effector molecule of adaptive
immunity, can distinguish between two protein molecules that differ in only a
single amino acid.
(2) Diversity:
Adaptive immunity is capable of generating tremendous diversity in its
recognition of molecules, allowing it to recognise billions of uniquely different
structures on foreign antigens. It is due to the variability in the structures of the
antigen-binding sites of lymphocyte receptors for antigens.

8. (3) Immunological Memory:
Once our body encounters a pathogen, it activates the immune system to
destroy it. It also remembers what antibodies were released in response to that
pathogen, so that, the next time it enters, a similar procedure is followed by the
body to eliminate it.
(4) Discrimination between Self and Non-self:
It can recognise and respond to foreign molecules (non-self) and can avoid
response to those molecules that are present within the body (self) of the
animal.

10. 1. Active immunity:
In this immunity person’s own cells produce antibodies in response to
infection or vaccination.
It is slow and takes time in the formation of antibodies.
It is long lasting and is harmless.
Active immunity may be natural or artificial.
Types of Active immunity
1.Natural active immunity
2.Artificial active immunity

11. NATURAL ACTIVE IMMUNITY
May be as a result of clinical infection.
Measles infection gives the patient life long immunity.
Adults in developing countries have natural active immunity against polio
because of inapparent infections in childhood.
Duration of immunity depends on pathogen.
1.Short term –Eg. Influenza
2.Long term –Eg. Measles, Chicken pox
Bacterial infections provide with less degree of immunity.

12. ARTIFICIAL ACTIVE IMMUNITY
Resistance induced by vaccines.
Vaccines are preparations of live or killed microorganisms or their products
used for immunization.
Bacterial vaccines
1.Live : BCG vaccine
2.Killed : Cholera vaccine
3.Subunit : Typhoid Vi antigen
4.Bacterial products : Tetanus toxoid
Viral vaccines
1.Live : OPV –Sabin
2.Killed : IPV –Salk
3.Subunit : Hepatitis B vaccine

13. Passive immunity:
If host does not produce antibodies itself but antibodies produced in other
host provides immunity, than it is known as Passive immunity.
No infections
Readymade antibodies are administered
No latend period
No negative phase
Immediate protection
No secondary response
Types of Passive immunity
1.Natural passive immunity
2.Artificial passive immunity

14. NATURAL PASSIVE IMMUNITY
Resistance transferred from mother to baby
Via placenta
Breast milk –colostrum –IgA
IgM production by fetus can start from 20
th
week of intrauterine life
Inadequate immunity at birth
By 3 month of age –immunological independence
Eg. Tetanus toxoid during pregnancy

15. ARTIFICIAL PASSIVE IMMUNITY
Resistance transferred by administration of antibodies
1.Hyper immune sera
2.Convalescent sera
3.Pooled human gamma globulin
Used for prophylaxis and therapy

16. HYPERIMMUNE SERA
Anti-Tetanus serum (ATS)
Prepared from hyper immunized horses
Temporary protection
CONVALESCENT SERA
Sera of patients recovering from disease
Contain high levels of antibody specific to the disease
Eg Viral Infection-Hepatitis A
POOLED HUMAN GAMMA GLOBULIN
It taken fr healthy adults
Has antibodies to all pathogens prevalent in the area

20. Components of Acquired Immunity:
Acquired immunity has two components:
humoral immunity or Antibody mediated immune system (AMIS) and cellular
immunity or cell mediated immune system (CMIS).
Antibody Mediated Immune System (AMIS) or Humoral Immunity:
1.It consists of antibodies (specialised proteins produced in the body in response to
antigen) that circulate in the body fluids like blood plasma and lymph.
2.Certain cells of the bone marrow produce В lymphocytes and mature there. Since
В lymphocytes produce antibodies, therefore, this immunity is called antibody
mediated or humoral immunity.
3.Humoral immunity or antibody-mediated immune system (AMIS) provides defence
against most extracellular bacterial pathogens and viruses that infect through the
respiratory and intestinal tract.

21. Main Cells of AMIS
Formation of Plasma В cells and Memory В cells:
(a) Plasma В Cells (Effector В cells):
Some of the activated В cells enlarge, divide and differentiate into a clone of
plasma cells. Although plasma cells live for only a few days, they secrete
enormous amounts of antibody during this period.
(b) Memory В Cells:
Some activated В cells do not differentiate into plasma cells but rather remain as
memory cells (Primed cells). They have a longer life span. The memory cells
remain dormant until activated once again by a new quantity of the same
antigen.

23. MAIN CELLS OF CMIS
1. Helper T cells (TH)
2. Cytotoxic T cells (Tc) or Killer cells:
3. Memory T Cells (Primed Cells)
4. Suppressor Cells (Regulatory T cells (TR))

25. REFERENCE
Fathimunisa Begum -Immunology
http://www.slideshare.net/RiyazSheriff/acquired-immunity-
58238294?from_m_app=android
https://www.biologydiscussion.com/biology/immunity-types-components-
and-characteristics-of-acquired-immunity/1447
https://microbiologynotes.com/differences-between-primary-and-secondary-
immune-response/
https://www.onlinebiologynotes.com/cell-mediated-immunity-cmi-antigen-
specific-and-non-specific-cmi/
https://www.khanacademy.org/science/in-in-class-12-biology-
india/xc09ed98f7a9e671b:in-in-human-health-and-
disease/xc09ed98f7a9e671b:in-in-types-of-immunity-and-the-immune-
system/a/adaptive-immunity
https://www.vedantu.com/biology/difference-between-active-and-passive-
immunity

26. Skills Gained
Communication skills
Confidence
Presentation skills
Time Management
Gained Subject knowledge