Horticulture unit 1 536899WA0010 copy.pptx

Horticulture

1. WHOLE ORGANISM & DESIGNED VACCINES SHAHLA SHIBIN V K ROLL NO :21

2. VACCINES A Vaccine is a medical preparation given to provide immunity from a disease. vaccines uses a variety of different substances ranging from dead microorganisms to genetically engineered antigens to defend the body against potentially harmful microorganisms. First vaccine - Edward Jenner(1796)-smallpox

3. DESIGNED VACCINE WHOLE ORGANISM VACCINE

4. WHOLE ORGANISM VACCINE Whole organism vaccines utilizes whole bacterium or virus to actively immunize the body against that particular pathogen. These are administered in small amount so as to produce immunity without causing disease.

5. WHOLE ORGANISM VACCINE LIVE ATTENUATED INACIVATED (KILLED )

6. 1)LIVE ATTENUATED Uses microorganisms that are attenuated so they lose their ability to cause significant disease. But retain their capacity for transient growth within an i noculated host. Generally, microorganisms are attenuated by growing them in adverse conditions for a long period of time. This enables to select better mutant that are suited to grow in abnormal culture environment and are thus less capable of growth in the natural host.

7. Examples : Bacillus Calmette - Guerin (BCG). ● Attenuated strain of Mycobacterium bovis ● Developed by growing M.bovis on medium containing increasing concentrations of a bile. Sabin polio vaccine ● Virus is grown in monkey kidney epithelial cells. Measles vaccines ● Virus is grown i n duck embryo cells and later in human cell lines.

8. ADVANTAGES ● Due to their capacity for transient growth, they are providing prolonged immune system exposure to the individual epitopes on the attenuated organism. ● This results in increase in immunogenicity and production of memory cells. ● only a single immunization is required and no booster dose is needed. DISADVANTAGES Possibility that they will revert to a virulent form. ● The rate of reversion of the sabin polio vaccine leading to subsequent paralytic disease is about onecase in 2.4 millions doses of Vaccines.

9. 2)INACIVATED (KILLED) Pathogen is inactivated or killed with chemicals or heat or radiation, so that they are no longer capable of replication. ❖ Surface epitope is maintained intact without modification ever while inctivating. ❖ Inactivation by of heating is generally not satisfied because it denatures the proteins, and thus disintegrates the epitopes. ❖ Inactivation by chemical treatment or various alkylating agents are proved successful.

10. EXAMPLES : Salk polio vaccine Produced by formaldehyde inactivation Rabies vaccine Japanese encephalitis vaccine ADVANTAGES • Incapable of converting in to virulent form • Stable and safer than live attenuated vaccine DISADVANTAGES • Elicit weak humoral immune response • require repaeted booster

11. DESIGNED VACCINES The risks associated with attenuated or killed whole organism vaccines can be avoided with vaccines that consists of specific, purified macromolecules derived from pathogens.

12. DESIGNED VACCINES Subunit vaccine Recombinent vector vaccine DNA vaccine Multivalent subunit vaccine Conjugate vaccine

13. 1)SUBUNIT VACCINE Vaccines that use components of a pathogenic organism rather than the whole organism are called subunit vaccine. • Recombinant DNA technology is very well suited for developing a new subunit vaccine • 3 general form inactivated exotoxins/toxoids, capsular Polysaccharides recombinant protein antigens.

14. TOXOIDS Production - purification of bacterial exotoxins and then Inactivating the toxins with formaldehyde to form toxoid. • Vaccination with the toxoid induces anti- toxoid antibodies, which are also capable of binding to the toxins and neutralizing its effect s. • Condition -Detoxification without excessive modification of the epitope structure. Eg: • Diphtheria & tetanus vaccines

15. CAPSULAR POLYSACCHARIDES Prepared from purified bacterial capsular Polysaccharides Coating the Capsule with antibodies and/or complement greatly increases the ability of macrophages and neutrophils to phagocytose such pathogens. Eg : vaccines for streptococcus pneumoniae _ pneumococcal pneumonia, vaccine for Neisseria meningitidis - bacterial meningitis

16. RECOMBINENT PROTEIN ANTIGENS A number of genes encoding surface antigens from Viral, bacterial and protozoan pathogen have been successfully cloned in to cellular expression system (Bacterial/yeast/mammalian call)for use in Vaccine development. Eg : Hepatitis B Vaccine. -developed by cloning the gene for the major hepatitis B. surface antigen ( HBsAg ) and expressing it in yeast cell

17. ADVANTAGES Using purified protein, so that preparation is Safe nd Stable. DISADVANTAGES - Complex to manufacture. - Purification is Costly antigenicity may decreased require booster shorts.

18. 2)RECOMBINENT VECTOR VACCINE genes that encodes antigens isolated from a virulent pathogen can be inserted in to attenuated (non-virulent) viruses or bacteria. The attenuated recombinant organisms serves as vectors, replicating within the host and expressing the gene product of the pathogens Recombinant vector vaccine has been prepared utilizing existing licensed live, attenuated vaccines and adding to them genes encoding antigens present on newly emerging Pathogen such chimeric virus vaccines can be more quickly tested and approved than an entirely new product.

19. A number of organisms have been used for vector vaccines, including vaccinia virus, the canary pox virus, attenuated polio virus and adenovirus. Vaccinia virus widely employed as a vector for the design of new vaccines. This large, complex virus, with genome of about 200 genes, can be engineered to carry several dozens foreign genes without impairing its capacity to infect host cells and replicate. Administration by dermal scratching, causing limited localized infection in host cells If foreign gene product expressed by the vaccinia virus is a viral envelope protein, it get inserted in to the membrane of infected host cell -induce CMI & HMI

20. PRODUCTION

21. 3)DNA VACCINES In this class of vaccines, plasmid DNA encoding antigenic proteins is injected directly in to the muscles of the recipient, where they can integrate in to the chromosomal DNA or exist as episomes. Antigen expression by both muscle cells and local dendritic cells. Muscles take up the DNA and the encoded protein antigen is expressed, leading to both humoral and cell- mediated immunity. Encoded proteins expressed in the host in its natural form-no denaturation or modifications.

22. DNA vaccines cause prolonged expression of the antigen, generate significant immunological memory. Eg: DNA vaccine for malaria, HIV, influenza, ebola, herpes virus etc. ADVANTAGES • No refrigeration of plasmid DNArequired • Eliminating long term storage challenge. • Lower cost and complexity DISADVANTAGES • only be done for antigens that are protein.

23. 4)CONJUGATE VACCINE Vaccine containing a Polysaccharide antigen ( usually bacterial capsular Polysaccharides) joined covalently to a carrier molecule ( usually a protein) to enhance immunogenicity. It is more recognizable to the immune cells , resulting in stronger responses. Polysaccharide antigens are covered by slime protected from WBCs, immature immune system of young people difficulties in recognizing certain Polysaccharide antigens – conjugate vaccines overcome this problems

24. Conjugate vaccines activate TH cells there by helps in class switching from IgM to IgG, but Polysaccharide vaccines can not alone activate TH cells only B cell responses. T cells produce more vigorous immune response and promote immunological memory Eg : Vaccine against Haemophilus influenzae type B -cause Bacterial meningitis ( capsular Polysaccharides bind to tetanus toxoid ) Pneumococcal vaccine and meningococcal vaccine.

25. Combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger response to the weak antigen. ADVANTAGES • Cost effective • Long lasting protection •Prevent asymptomatic carriage of Disease. DISADVANTAGES • Preparation is more complex and complicated • May cause mild side effects. • Loss of immunogenicity during conjugation

26. 5)MULTIVALENT SUBUNIT VACCINE Synthetic peptide vaccines that contain both and B cell and t cell epitopes. It can present multiple copies of a given peptide or a mixture of peptides to the immune system. Works intracellularly, therefore effective in CTL response Peptide can be processed &presented via class1 MHC. Solid matrix Ag-Ab complex(SMAA) Detergent

27. SMAA COMPLEXES SMAA – by attaching monoclonal antibodies to particulate solid matrices and then saturating the antibody with the desired antigen. The resulting complexes are used as vaccines.

28. By attaching different monoclonal antibodies to the solid matrix, possible to bind mixture of peptides or proteins, composing immunodominant B and T cell epitopes to the solid matrix. These multivalent complexes shown to induce vigorous humoral and cell mediated responses. Particulate nature contributes to increased immunogenicity by facilitating phagocytosis by phagocytic cells.

29. DETERGENT Use detergents to incorporate protein antigens in to protein micelles, lipid vesicles ( liposome) or immunostimulating complexes. Mixing proteins in detergent and then removing the detergent from micelles. The individual proteins orient themselves with their hydrophilic residues towards the aqueous environment and hydrophobic residues towards the centre. Liposomes Containing protein antigens are prepared by mixing the proteins with a suspension of phospholipids under conditions that form vesicles bounded by a bilayer.The proteins are incorporated in to the bilayer with the hydrophilic residues exposed

30. Immunostimulating complexes (ISCOMs) are lipid carriers prepared by mixing protein with a detergent and a glycoside called Quil A Liposome containg protein antigens are prepared by mixing the proteins with a suspension of phospholipids under conditions that form vesicles bounded by a layer. Eg : Membrane proteins from various pathogens, including influenza virus, hepatitis B virus, and HIV have been incorporated and are currently being assessed as potential vaccines.