A SEMINAR ON IMMUNOSTIMULANTS Presented by: K. Shiny 1008-18-884-006 M.Pharm 1 st year Pharmaceutical chemistry department
CONTENTS: Introduction. Immunostimulant definition . Functions of immunostimulant . Types of immunostimulants . Classification. Conclusion. Reference.
INTRODUCTION IMMUNITY: The ability of an individual to fight against the disease causing organisms or foreign antigen is called as immunity. IMMUNE SYSTEM: The network of organs, cells & proteins that protect the body from harmful, infectious agents such as bacteria , viruses , fungi etc., is called as immune system.
ROLE OF IMMUNE SYSTEM: The aim of the immune system is to protect us from microorganisms that may us harm. The first line of defense is the skin, which forms a protective layer around us . The second line of defense is the immune system where the defenders include blood cells, which are able to synthesize cells called macrophages ,monocytes ,lymphocytes ,phagocytes as well as the blood and blood cells which synthesize.
TYPES OF IMMUNITY:
DEFINITION Immunostimulants are the substances that increases the ability of the immune system to fight against infection & disease. Many compounds (drugs , vitamins &immune system components) can stimulate our immune system against different micro-organisms. These drugs are useful in infection, immunodeficiency & cancer.
TYPES OF IMMUNOSTIMULANTS Based on action there are two types of immunostimulants : Specific Immuno stimulants : Provide antigenic specificity in immune response such as vaccination. Eg: Vaccine. Π . Non-specific Immuno stimulants : These act irrespective of antigen specificity , so act against all antigens. Eg: Immunoglobulins.
FUNCTIONS OF IMMUNOSTIMULANTS Immunostimulants activate different elements of the immune system in humans and animals. They develop the non-specific immunotherapy and immuno prevention by stimulating the major factors of the immune system including phagocytosis, properdin and complement systems , protective secretory IgA antibodies, α- and γ-interferon release, T- and B-lymphocytes, synthesis of specific antibodies and cytokines, and synthesis of pulmonary surfactant. There are several reasons for using the immunostimulants in the control of various infectious diseases including : a) antibiotic resistance of the bacteria ; b) allergic reactions to antibiotics; c ) immunosuppressive effects of antibiotics; and d ) Poor effects of the antibiotics in viral infections
CLASSIFICATION OF IMMUNOSTIMULANTS Vaccines - Poliomyelitis vaccine , Rota virus vaccine. Adjuvants. Immunoglobulins. Miscellaneous agents used as stimulants : Levamisole . Thalidomide. Isoprinosine. Immunocynin ,.
Vaccine is a biological preparation that improves immunity to a particular disease. Vaccine contain certain agents which stimulates immune system to recognize the foreign agents. Ex: BCG vaccine for tuberculosis. Vaccines are suspensions of dead microorganisms (inactivated) or attenuated but live. In general live, attenuated vaccines are antigenically more potent than the inactivated vaccines. Live vaccines achieve lifelong immunity with single dose but multiple doses are required with polio vaccine. I. Vaccines
POLIOMYELITS VACCINE: It is administered as orally( sabin ) and as parental ( salk ). The salk vaccine ,developed by Johnsalk 1 st polio vaccine ,which induces only limited resistance to growth of the virus in the intestine and thus does not affect the carrier state (excretion of virus in feces). The vaccine is given by SC or IM injection, 3 doses each of 0.5ml at interval of 4-6 weeks between 1 st and 2 nd dose and 12 months between 2 nd and 3 rd dose. Adverse Effects: Mild and consists of local pain at the site of injection and fever.
ROTA VIRUS VACCINE: It is a vaccine used to protect against rotavirus infections. These viruses are the leading cause of severe diarrhea among young children ( 3 years). The available rotavirus vaccine is human bovine reassortant vaccine . It is safe and effective. The oral vaccine is administered in three, monthly doses from the age of 6-12 weeks to the age of 32 weeks. It may be with other vaccines. Adverse Effects: It may cause mild diarrhea or vomiting in some children.
Vaccine Immunizing Agent Route Adverse Reactions BCG Live attenuated M.bovis ID Fever, regional adenitis Typhoid Whole cell, killed bacteria IM Fever ,local swelling Cholera Inactivated bacteria SC;IM Fever; swelling Diphtheria Inactivated toxins IM Local reactions Tetanus Inactivated toxins IM Local reactions Typhus vaccine Killed organisms SC Allergic reactions
II. ADJUVANTS An adjuvant is a substance that increase immune response to foreign antigen. Adjuvants may be added to a vaccine to modify the immune response by boosting it such as to give a higher amount of antibodies and a longer-lasting protection. Adjuvants are also used in the production of antibodies from immunized animals. The most commonly used adjuvants include aluminum hydroxide and paraffin oil .
Aluminum Hydroxide: It is a white gelatinous precipitate in aqueous suspension. The mechanism of action includes the formation of a depot at the injection site, which enabling the slow release of antigen and the stimulation of antibody producing plasma cells. Side Effects: Pain at the site of injection. Fever .
III. IMMUNOGLOBUINS: Antibody molecule consists of two light and two heavy chains composed of different domains
The Fab fraction serves as the antigen binding site. The specific antigen-binding properties of an IgG molecule are conferred by the three dimensional stearic arrangement inherent in the amino acid sequence of the variable region of the light and the heavy chains of the molecule . This portion of the IgG molecule is called the idiotypic determinant . FC fragment is relatively constant and determines the effectors function of the antibody. The FC domain is necessary for interaction with complement cascade.
Human Normal Immunoglobulin: Roughly plasma protein can be fractionated into four important components, viz. albumin and the alpha, beta and gamma globulins. The Ig obtained from pooled , human, adult blood is known as immune serum , more selective type of a gamma globulin against a particular infection obtained from the blood of individuals ,this is called as Hyper Immune Serum or Human Specific Ig. Adverse Reactions: It can cause pain at the site of injection Allergic reactions can occur It may give rise to fever ,flushing, shivering joint pain and nausea. Therapeutic Uses: Infective Hepatitis ( gamma globulin can suppress the clinical symptoms). The dose of HNI recommended is 750 mg.
Diphtheria : Hyper immune specific serum can be used both prophulactically and therapeutically. Monoclonal antibodies: Are the antibodies produced by single clone of B cells, which are now being used for diagnostic procedures and therapeutic purposes. Mechanism of action : They block the characteristic of targeted antigen, its function ,its cell surface and tissue distribution, to produce immune conjugates. Adverse reactions: Hypersensitivity reactions. Activation of inflammatory cells. Therapeutic uses of mAb : Used as immunosuppressant. In auto immune disease .
IV. MISCELLANEOUS AGENTS: LEVAMISOLE: It is available as ergamisol or vermisol . First synthesised to treat parasitic worm infections. Used as immuno modulating agent in cancer. It is given orally, which is rapidly absorbed and it crosses BBB. Metabolized in liver and excreted through urine. It restores depressed B and T cells functions.
Dose: It is administered in a dose of 50mg three times a day for 4-6 weeks. Adverse Effects: Nausea. Muscle pain. Skin rashes. Drowsiness. Mechanism of action: It acts by modulating cell mediated immunity. The ganglia in worms are stimulated causing paralysis and expulsion of live worms , by the activation of macrophages.
ISOPRINOSINE: It is also available as inosine. Useful as immunostimulant in immunodefecient patients. It is antiviral agent. It acts as a immunostimulant , an analog of thymus hormones. It is most commonly used to treat the rare measles complication subacute sclerosing panencephalits .
Mechansim of action : Isoprinosine is a synthetic purine derivative with immunomodulatory and antiviral properties. The action of Isoprinosine can be summarized as follows: It normalizes the cell-mediated immunity by stimulating the differentiation of T-lymphocytes intoT -helper cells, and increasing production. It increases the humoral immune response by stimulating the differentiation of B- lymphocytes into plasma cells and by enhancing antibody production. It inhibits viral growth by suppressing viral RNA synthesis while potentiating depressed lymphocytic action
Dose: Patients with cancer can take 2000 mg to 3000 mg of Isoprinosine daily for two months Adverse Effects: Nausea. Headache. Vomitting . Abdominal pain. Dizziness. Diarrohea .
CONCLUSION From this seminar we can conclude that immunology is probably one of the most rapidly developing areas of medical biotechnology research and has great promises with regard to the prevention and treatment of a wide range of disorders , the inflammatory diseases of skin, gut , respiratory track , joints and central organs. Immunomodulators are going to be a central part of 21 medicine.
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