Interferons & interleukines

definition,types,mechanism of action,marketed formulations,

1. INTERFERONS AND INTERLEUKINS Binu anand 1 ST Yr M.Pharm Nazareth college of pharmacy 1

2. An antiviral substance & is the first line of defence against viral attacks. Term ‘interferon’ orginated from the ‘interference’ of this molecule on virus replication. Interferons are a family of host coded proteins produced by cells on induction by viral or non-viral inducers. Interferons by itself has no direct action on viruses but it acts on other cells of the same species, rendering them refractory to viral infection. INTERFERONS 2

3. Interferons are inactivated by proteolytic enzymes but not by nucleases or lipases. They resist heating at 56-60 o C for 30-60mins & stable over a range of pH 2-10, except gamma IFN which is liable at pH 2. Mol.wt of 17000 Da - non dialysable & non-sedimentable. Poorly antigenic, so no routine tests are available for their detection & estimation. Interferon assay-based on its biological activity, such as ability to inhibit plaque formation by sensitive virus. 3

4. Potency of IFN is expressed as International Units(IU) per mL. Interferons are non-toxic, non-antigenic, diffuses freely in the body & has a wide spectrum of antiviral activity. So it is an ideal candidate for use in prophylaxis & treatment of viral infection. Interferons are stored at 2 – 8 ° c 4

5. Proteins in nature & many of them are glycoproteins. Broadly classified into 3 groups- structure & function. 5

6. Alpha interferon Also known as Leukocyte interferon. Produced by leukocytes following induction by suitable viruses. Non-glycosylated protein. Atleast 16 antigenic subtypes have been identified. Beta interferon Fibroblast interferon. Produced by fibroblasts & epithelial cells following stimulation by viruses or polynucleotides. Is a glycoproteins. 6

7. Gamma interferon Immune interferon Produced by T-lymphocytes on stimulation by antigens or mitogens. Is a glycoprotein. More concerned with immunomodulatory & antiproliferative functions than with antiviral defence. It also differs from alpha & beta interferons in having a separate cell receptor. 7

8. General Action of Interferons Tissue cell is infected by a virus Releases interferon Interferon will diffuse to the surrounding cells & binds with receptor. Production of a protein that prevents the synthesis of viral proteins. Prevents the spread of the virus throughout the body.

9. PRODUCTION OF RECOMBINANT INTERFERONS The complementary DNA(cDNA) was synthesized from mRNA of a specific interferon. Inserted to a vector(plasmid) which is introduced into E.coli or other cells. IFN can be isolated from culture medium. This is the basic mechanism of producing recombinant IFNs. 9

10. THERAPEUTIC APPLICATION OF IFNs Used for treatment of a large no:of viral diseases & cancers. Alpha IFNs Hepatitis B & C, chronic myeloid leukemia, multiple myeloma, Kaposi’s sarcoma, melanoma. Beta IFNs Multiple sclerosis Gamma IFNs Chronic granulomatous disease, renal cell carcinoma, chronic myeloid leukemia. 10

11. IFNs cause the death of cancerous cells by stimulating the action of natural killer(NK) cells, a specialized form of lymphocytes that can destroy cancer cells. Also used for the treatment of common cold & influenza. For this purpose, IFNs can be used as nasal sprays. Common side effects of IFNs fever, malaise, fatigue, muscle pains. High levels of IFNs cause kidney, liver, bone marrow & heart toxicity. 11

12. MARKETED FORMULATIONS 12 BRAND NAME TYPE USE Alferon N Human leukocyte–derived interferon alfa-n3 Genital and perianal warts Roferon -A Recombinant interferon alfa-2a Hairy cell leukemia,AIDS Intron A Recombinant interferon alfa-2b Hairy cell leukemia,AIDS Avonex , Rebif Recombinant interferon beta-1a Multiple sclerosis Betaseron Recombinant interferon beta-1b Multiple sclerosis

13. INTERLEUKINES These are a large group of cytokines produced mainly by T cells, although some are also produced by mononuclear phagocytes (or) by tissue cells. The interleukins were first described as signals for communication between white blood cells ( leuk - from leukocytes). Currently, it is well-known that these molecules are produced and used as signalling molecules in many cells of the body, in addition to immune cells. 13

14. Interleukins are secreted rapidly in response to an infectious agent, it travels to its target cell and binds to the receptor molecule on the cell’s surface that triggers a cascade of signals within the target cell altering the cell’s behaviour. Interleukins represent a broad family of cytokines that are made by hematopoietic cells and act primarily on leukocytes. Interleukins are stored at 2 – 8°c There are currently 35 well-known interleukins, however, there are many more to be found and characterized. 14

15. Mechanism of action and Dose Mechanism of action; Immunotherapy with IL activates cytotoxic T -cell against RCC Dose and adminstration ; Interleukin administered via intravenous (iv) injection as high dose (usually defined as 600,000 – 720,000 units/kg). Lower dosage iv and subcutaneous IL-2 are also prescribed for kidney cancer. 15

16. TYPES OF INTERLEUKINES Interleukin Primary Cell Structure Primary Activities IL –1 α /IL-1 β Macrophages, NK Cells, B cells Inflammation IL-2 T cells Activates T cells IL-3 T cells Haematopoietic growth factor IL-4 T cells B cell growth IL-5 T cells Eosinophil & B cell growth IL-6 T cell & fibroblasts Inflammation IL-7 Stromal cells B & T cell growth 16

17. Continued …… Interleukin Primary Cell Structure Primary Activities IL-8 Macrophages Chemoattractant for neutrophils IL-9 Activated T cells T cell growth & Potentiates  IgM , IgG & Ig E IL-10 B cells, T cells B cell growth / inhibition of cytokine synthesis by T cells IL-11 Bone marrow stromal cells Haematopoietic co-factor IL-12 Macrophages, B cells Induction of cell mediated immunity IL-13 T cells B cell growth 17

18. PRODUCTION OF INTERLEUKINES Antigen is internalized and degraded by the macrophages, processed, and then presented on the macrophage surface to the resting T lymphocyte in conjunction with an MHC molecule. Once the T-cell receptor engages the MHC molecule plus antigen, the T cell becomes activated and secretes IL-2, IL-3, IL-4 , IL-5, and IL-6. Interleukins 2,4, 5, and 6 enable activated T cells to undergo clonal expansion. 18

19. THERAPEUTIC APPLICATION OF INTERLEUKINES Used to enhance T-cell activation in immunodeficiency diseases. Used in the treatment of cancers and other infectious diseases. Used to reduce graft rejection. 19

20. MARKETED FORMULATIONS 20 BRAND NAME TYPE USE A ldesleukin r ecombinant human IL-2 (rIL-2) Chronic hepatitis C, and Chronic hepatitis B OPRELVEKIN Recombinant human IL-11 Hairy cell leukemia,AIDS MUPLESTIM IL-3 Hairy cell leukemia,AIDS SIGOSIX IL-6 Multiple sclerosis

21. CONCLUSION Interferons (IFN) are cytokines that are responsible for the activity of the immune system . Interleukins are biologically active glycoproteins derived primarily from activated lymphocytes and macrophages. They mediate their action by binding with high affinity to receptors which belong to a limited number of structural families Immunity are produced mainly by activated macrophages 21

22. REFERENCES Johnson, Howard M., Fuller W. Bazer , Brian E. Szente , et al. "How Interferons Fight Disease."  Scientific American  (May 1994): 68–76. Meulen , Volkerter , N. Stefan. "Inhibition of Major Histocompatibility Complex Class II-Dependant Antigen Presentation by Nutralization of Gamma Interferon Leads to Breakdown of Resistance against Measles Virus-Induced Encephalitis."  Journal of Virology  75 (2000):1–13. Seppa , Nathan. "Interferon Delays Multiple Sclerosis."  Science   News  158 (November 2000): 280–281. Interferons and Interferon Therapy, R.Priyanka et al /J. Pharm. Sci. & Res. Vol. 6(12), 2014, 400-403 22

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