Antigens, haptens and immunogens were discussed. Key points:
- Antigens are molecules that induce an immune response through binding antibodies or T cells. Immunogens can induce immune responses while antigens may only bind antibodies/T cells.
- Antigens are classified based on origin (exogenous, endogenous, autoantigens), chemical structure (proteins, polysaccharides etc.), and type of immune response generated (T cell dependent/independent).
- Immunogenicity depends on antigen properties like size, structure and degradability as well as the exposed biological system. Larger complex molecules tend to be more immunogenic.
Antigen is any substance that induces an immune response in the body. There are two main types: complete antigens that can induce an immune response on their own, and incomplete antigens or haptens that require a carrier molecule to become immunogenic. Antigens are recognized by immune cells through antigen determinants or epitopes. For a response, antigens must be processed and presented by antigen-presenting cells to be recognized by T cells through MHC molecules. The properties of an antigen like its size, structure, and route of administration influence its ability to induce an immune response.
This document discusses antigens and haptens. It defines antigens as macromolecules that elicit an immune response through antibody formation. It classifies antigens as exogenous or endogenous, and further divides endogenous antigens. It distinguishes immunogenicity from antigenicity and defines haptens as low molecular weight compounds that are antigenic but not immunogenic unless coupled to a carrier protein. It provides examples of haptens and describes tests used to detect antigens and haptens.
1. An immunogen is an agent capable of inducing an immune response, while an antigen is any agent capable of binding to components of the immune system. All immunogens are antigens, but not all antigens are immunogens.
2. Haptens are low molecular weight compounds that are incapable of inducing an immune response alone but can do so when conjugated to a carrier molecule like a protein.
3. For a substance to be immunogenic, it must be foreign, have a high molecular weight and chemical complexity, be degradable, and interact with MHC molecules.
This document defines and discusses antigens from several perspectives:
1) It provides a brief history of the term "antigen" and its definition as a substance that stimulates antibody production.
2) It classifies antigens based on their immunogenicity as complete or incomplete antigens.
3) It categorizes antigens based on their origin as exogenous, endogenous, autoantigens, isoantigens, or heterophile antigens.
4) It lists 10 properties that determine an antigen's ability to stimulate an immune response, including foreignness, size, chemical nature, and specificity.
5) It briefly discusses superantigens and common tests used to detect antigens.
The document discusses antigenicity and immunogenicity. It defines antigens as substances that bind to antibodies or immune cell receptors, while immunogens are antigens capable of inducing an immune response. All immunogens are antigens, but not all antigens are immunogenic. The document outlines key characteristics that determine a substance's immunogenicity, including its foreignness, chemical composition, complexity, size, and dose. It also discusses factors like the host's genetic makeup and route of entry that influence the immune response. Overall, the document provides an overview of the differences between antigens and immunogens, and the features that determine a substance's ability to induce immunity.
What is antigen
What is epitope & paratope?
Classification of antigen
Pro antigen
Superantigens
Antigenicity
Determinants of antigenicity
Test for antigen detection
This document discusses antigens and their classification. It defines antigens as substances that can induce an immune response. Antigens are classified as either exogenous (external) or endogenous (internal) antigens. Exogenous antigens enter the body from the external environment, while endogenous antigens are further divided into xeno-genic, allogenic, and autologous antigens based on their origin. The document also discusses the properties of immunogens and antigens, as well as factors that contribute to immunogenicity.
Presentation for immunology and microbiologyriazsohail448
Antigens are substances that can induce an immune response. They are typically found on pathogens but can also be produced by the body's own cells. Antigens vary in their source (exogenous or endogenous), molecular structure (proteins, polysaccharides etc.), and ability to elicit immune responses. The immune system recognizes specific regions of antigens called epitopes. Antigens are important for vaccine development and play a role in diseases, transplants, and immunotherapy.
(5) the classification and the significance of the Antigenic molecules.pptxAmirRaziq1
This document defines and classifies different types of antigenic molecules. It discusses exogenous and endogenous antigens, autoantigens, tumor antigens, superantigens, mitogens, complete and incomplete antigens. It also describes factors that influence antigen immunogenicity, including properties of the antigen and the biological system. Epitopes and adjuvants are explained. Antigens can stimulate immune responses through various mechanisms such as binding to antibodies or T-cell receptors.
This document summarizes screening methods for immunomodulators. It describes in vitro and in vivo methods for testing immunological factors. Some key in vitro methods discussed include inhibition of histamine release from mast cells and mitogen-induced lymphocyte proliferation assays. Key in vivo models described are the anti-anaphylactic activity (Schultz-Dale reaction) assay and delayed type hypersensitivity testing in sensitized animals. The document also provides details on the procedures and evaluations for some of these screening methods.
This document provides information on various topics related to immunology:
1. It defines key terms like antigen, immunogen, hapten, allergen, and tolerogen. It also describes different types of antigens.
2. It discusses the primary and secondary lymphoid organs of the immune system, including the thymus, bone marrow, spleen, lymph nodes, and more.
3. It provides an overview of hematopoiesis, the process by which the body produces blood cells, and where this process occurs throughout development and in adults.
This document provides an overview of immunology and immunity. It discusses the study of immunology, the function of the immune system including innate immunity, acquired immunity, antigens, and the effects of age on the immune response. Innate immunity provides non-specific protection through physical and chemical barriers while acquired immunity develops specific responses with immunological memory after exposure to antigens. Both humoral and cell-mediated immunity play important roles in the immune response to infection.
Antigen is a substance that stimulates the immune system to produce antibodies against it. Antigens can be proteins, polysaccharides, lipids, or nucleic acids. The ability of a substance to induce an immune response is called immunogenicity, while the ability to bind antibodies is called antigenicity. Factors like molecular size, complexity, shape, stability, and foreignness determine a substance's antigenicity. Antigens contain epitopes that antibodies and T cells recognize. Common antigens include microbial antigens from bacteria, viruses, and other microbes, as well as non-microbial antigens like pollen and snake venom.
Antigens are substances that stimulate an immune response and react with the products of that response. They can be classified based on their origin (exogenous, endogenous, autoantigens, tumor antigens) and properties (immunogenicity, antigenicity, epitopes). Antigens are recognized by B cells and T cells and can stimulate both humoral and cell-mediated immunity. Adjuvants are substances that enhance the immune response to antigens.
This document discusses antigens and concepts in vaccine development. It begins by defining antigens and classifying them as exogenous or endogenous. It then discusses the differences between immunogenicity and antigenicity, and lists factors that influence immunogenicity such as molecular size, chemical composition, and adjuvants. The document also covers epitopes, mitogens, and superantigens. Finally, it discusses the different stages of vaccine development from pre-clinical to clinical trials and licensing, and methods used in vaccine manufacturing.
Immunogens are substances that can induce an immune response, while antigens are substances that can bind to antibodies or T-cell receptors. Not all antigens are immunogenic. The properties of an effective immunogen include foreignness, molecular size over 100,000 Daltons, chemical complexity, and the ability to be processed and presented by antigen-presenting cells. The immunogenicity of a substance depends on additional factors like dosage, route of administration, use of adjuvants, and host genetics. Antigens can be classified as exogenous, endogenous, autoantigens, or complete versus incomplete antigens.
Antigens are substances that induce an immune response and can combine with immune system products like antibodies and T cell receptors. They come in various types, including complete antigens that induce antibody formation on their own and incomplete antigens or haptens that require a carrier protein. Antigens are classified based on their ability to induce T cell dependent or independent responses. Superantigens can directly activate T cells without antigen processing. Diseases may result from exposure to bacterial or viral superantigens.
This document defines and describes various types of antigens. It discusses:
- The concept of antigens as substances that induce immune responses and react with immune system products.
- Different types of antigens including exogenous, endogenous, autoantigens, and tumor antigens based on their origin.
- Characteristics of antigens including immunogenicity, antigenicity, and properties that influence antigenicity.
- Antigenic epitopes as the portions of antigens that interact with immune cells and determine antigen specificity.
- Classification of antigens as thymus-dependent or -independent and examples like superantigens that can activate large numbers of T cells.
- Adjuvants as substances that enhance immune responses
Immunomodulators modern and ayuvedic conceptsJAYAKRISHNAN K
A MINOR SIMPLE PROJECT ON IMMUNOMODULATORS. It explains types of immunity, hyper sensitivity, allergy, immunostimulants, immunoadjuvants, immunosuppressants etc. with relevant ayurvedic portions.
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Antigen_ppt(_RANJITHA_SL)_.presentation.
1. KUVEMPU
UNIVERSITY
PG DEPARTMENT OF BIOTECHNOLOGY
SAHYADRI SCIENCE COLLEGE
SHIVAMOGA.
SEMINAR TOPIC
ANTIGENS
SUBMITTED BY
UNDER THE GUIDENCE OF
RANJITHA SL
Dr. BANUMATHI
I MSc BIOTECHNOLOGY
LECTURER
Email Id: ranjithasl810@gmail.com
PG DEPARTMENT OF BIOTECHNOLGY
SAHYADRI SCIENCE COLLEGE
SAHYADRI SCIENCE COLLEGE
SHIVAMOGGA .
4. INTRODUCTION
• Antigens are molecules that tigger an immune
response in the body they are recognised by the
immune system as foreign or non self .the
immune system them mounts a defense against
these antigens. Often by producing antibodies.
• Antigens can be found on the surface of
bacteria, viruses, parasites, and other foreign
invaders. They can be also be present in
substances like pollen, dust mites, and non –
self antigens, allowing it to target foreign
substances without attacking the body’s own
tissues.
5. ANTIGENS
• Antigens are foreign substances that can be
recognized by the immunoglobulin receptor of B
cell or by the T cell receptors when complexed
with MHC
• IMMUNOGENICITY : The ability to induce a
humor/cell mediated response is a property of
a substance known as antigen called immunogen
• ANTIGENICITY : The ability to combine
specifically with antibodies or cell surface
receptors. all molecules that have the
property of immunogenicity also have the
property of antigenicity
6. IMPORTANCE OF ANTIGENS
Triggering immune response
Specificity
Activation of immune cells
Antibody production
Immunological memory
Vaccine development
Cancer Research and study
Diagnostic Tools
Immunotherapy development
8. EXOGENOUS ANTIGENS
❶ ORIGIN ❷ PROCESSING ❸ IMMUNE
RESPONSE
• Exogenous antigens are
foreign substances that
originate outside the
body.
• Once exogenous antigens
enter the body ,they are
taken up by immune cells,
primarily antigen-
presenting cells(APCs).
• The presentation
of exogenous
antigen on APCs
triggers an
immune response.
• They enter the body
through various routes
such as inhalation
,ingestion or
injection.
• APCs process their antigen
and present them on their
surface in a way that is
recognizable by the other
immune cells
• This involves
the activation of
T Cells and B
Cells
• They come from sources
like bacteria ,
viruses, fungi,
parasites and allergens
• The leading to
the production of
the antibodies
and cytotoxic
then T-Lympocytes
that can target
and eliminate the
9. ENDOGENOUS ANTIGENS
❶ ORIGIN ❷ EXAMPLES
• These antigens are produced
within the cells of the body
• Endogenous antigens includes
viral proteins, when viruses
infect a cells they take over
the cells machinery and
produces viral proteins
• They aren't foreign invaders
like exogenous(bacteria/viruses)
instead, they are generated by
normal cellular processes, such
as protein synthesis and
degradation.
• These processes can sometimes
leads to the production of
abnormal or altered protein that
the immune system recognize as
10. AUTO
ANTIGENS
❶ SELF
RECOGNISATION
❷ IMMUNE
DYSREGULATION
❸ TISSUE
DAMAGE
• The immune system
normally
distinguishes
between self and
non self.
• Autoimmune disorder
occur when the immune
system loses tolerance
for self antigen
• Autoantigens can trigger
the production of
antibodies and T cells that
attack the body's own
tissues.
• Autoantigens are
molecules that are
normally found
within the body
,but are mistakenly
recognized as
foreign by the
immune system.
• This can happen due to
a variety of factor ,
including genetic
predisposition,
environment triggers ,
and infections.
• This can lead to a wide
range of symptoms depending
on the specific tissues and
organs involved
• When the immune system
attacks self antigens,
11. TUMOR
ANTIGENS
Tumor antigen are those antigens that are presented by the
MHC – I (Major Histocompatibility Complex) molecules on the
surface of tumor cells.
These antigens can sometimes be presented only by tumor
cells and never by the normal ones .
In this case they are called tumor specific antigens (
TASAs)and typically result from a tumor specific mutation .
12. ON THE BASIS OF THE IMMUNE
RESPONES
IMMUNOGENS
:These may be
protein
/polysaccharide
s and can
generate an
immune response
on their own
1
TOLEROGENS :
It induces
immune
tolerance
,meaning it
does not
trigger an
immune
response
2
HAPTENS :
These are non
– protein
,small
molecules
that requires
a carrier
molecules to
induces an
immune
response
3
SUPERANTIGEN
:Stimulate a
very strong
immune
response and
it activating
a large
number of
immune cells
4
13. BASED ON
FUNCTION
Classified into types:
COMPLETE ANTIGEN : Substances which can induced
antibody formation by themselves and can react
specifically with these antibodies
INCOMPLETE ANTIGEN/HAPTENS :Substances unable
to induce antibody formation on its own but can
become immunogenic when covalently linked to
protein ,called carrier protein .
14. HAPTENS
• Haptens is derived from the Greek
word haptein mean “to fasten”.
• The term Hapten was first coined by
karl Landsteiner.
• These are low molecular weight
substance that are antigenic but
not immunogenic
• Its biological importances
substances-drugs ,peptide hormones
, steroid hormones , can function
as hapten.
• Eg :Penicillin
17. BASED ON BIOLOGICAL CLASSES OF
ANTIGEN
• T DEPENDENT ANTIGEN :Antigen that requires help
of T cells to activate B cells for antibody
production
• T INDEPENDENT ANTIGEN : Antigen directly
stimulate antibody production without the help
of T cells
18. PROPERTIES /FACTORS INFLUENCING OF
ANTIGENS
1. FOREIGNNESS
• Antigen must be foreignness to immune system
• According to Burnnet ’s clone selection theory , “forginness (non –
self) means substances that never contact with lymphocytes embryo
period.
2.CHEMICAL NATURE AND COMPOSITION
• Antigen are mainly proteins and polysaccharides
• Chemical nature of antigen protein ,polysaccharides ,nucleoproteins
,glycoprotein ,steroid hormones ,bacterial cells ,viruses
3.MOLECULAR SIZE
• The antigens have a molecular mass of 14000 to 600000 Da
• Highly antigenic are tetanus toxoid (50000),Egg albumin(42700
Da),Thyroglobulin (662000 Da)
19. CONTINUE…..
4.DEGRADABILITY
• Antigens that are easily phagocytosed are generally
more immunogenic.
• This is because for most antigen (T-dependent antigens)
the development of an immune response that the antigen
be phagocytosed , processed to helper T –cells by an
antigen presenting cell (APC).
5.DOSE AND CONCENTRATION: Higher doses and
concentration can trigger stronger immune responses.
6.GENETIC FACTORS: Genetic polymorphism and
epigenetic modification can affect immune responses to
specific antigens.
20. ADJUVENTS
• Substances that when mixed with an antigen and
injected with it ,enhance the immunogenicity of
that antigen.
• Used to boost the immune response when an
antigen has low immunogenicity or when small
amount of antigen are available
• Eg: The antibody response of mice to
immunization with BSA can be increased 5 fold
or more ,if the BSA is administered with an
adjuvant .
• Freund’s incomplete adjuvant : contains aqueous
solution , mineral oil , mannide monooleate.
• Freund’s complete adjuvant :Heat killed
22. CONCULSION
Antigens are
substances that
stimulate an immune
response , playing a
crucial role in the
body’s defense
against pathogens and
diseases .they can
originate from inside
r outside the body ,
antigens trigger an
immune response.