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Trying to provide all necessary information about IMMUNITY and IMMUNE SYSTEM

 Improving Immunity

                Your immune system has the ability to respond to diseases of all kinds. This is dependent on many complex reactions between the components of your immune system and the antigens on the disease causing agents. Your immune system can recognize invading substances, it can mount a specific attack on each invader as an individual, and it can remember that particular invader so that it can mount a secondary disease preventing attack upon later exposures.
 Your immune system is still the best weapon to fight a viral infection. It doesn't matter if it is a new virus like Avian Flu (H5N1), Severe Acute Respiratory Syndrome (SARS), West Nile Virus, or the common cold. If it's a virus, your immune system will try to kill it.
Your immune system's ability to protect your body is both instinctive and learned - in other words, it informs your body's actions with both innate and acquired responses. Each individual is born with innate immunity - the ability of your immune system to recognize what doesn't belong in the body. Along with passive defenses like skin, (your first line of defense), stomach acid and mucus, the innate immune system also contains active immune response mechanisms that include Natural Killer, or NK cells. Like all innate front line defense agents, NK cells do not need prior exposure in order to act. They simply recognize foreign cells and go to work.

Eat more black currants, green leafy vegetables red peppers and citrus fruits. All are good sources of vitamin C which boosts immune defences. Alternatively, supplement your diet with a daily dose of vitamin C. If you suffer from indigestion when taking vitamin C, a non-acid version, known as ester-C may be more easily absorbable.

A powerful antiviral, antioxidant and immune-boosting herb from the Peruvian rain forest, Cat’s Claw contains substances called alkaloids, which research has shown help fight infection. You can drink it in a tea (one cup a day should be enough for general maintenance) or in capsule (click here to order)

According to research a good old laugh triggers the release of the antibody immunoglobulin into the blood stream while the number of white T-cells also increases, both of which increase immunity. Watch a comedy on TV or rent a funny video. And as laughter is infectious sharing your jokes with your friends and family could help to keep them in the pink as well.

Regular light-to-moderate activity such as a daily 30-minute walk or swim in your local pool helps circulate the white blood cells around the body and tones up the cardiovascular system which in turn helps to strengthen your immune system.

Get your nightly sleep quota and you immediately increase your chances of warding off infection. Try to stick to a regular routine of wake up and and bed time to set your biological clock.

This popular herb has been shown to be more powerfully antibiotic than penicillin and tetracycline. It contains more than 200 compounds including allicin and sulphur – a strong free radical scavenger with super antioxidant properties. Eat garlic raw if possible as cooking destroys the chief active ingredient allicin. Try it sprinkled over salads or if you can’t bear the taste or smell, in an odourless capsule form.

Keep in regular contact with your friends as much as possible; studies show that positive feelings such as joy and love can boost your wellbeing significantly – so much so that people with a busy social life have been found to be four times less likely to catch a cold. Hugs and kisses can also boost physical and mental wellbeing, helping your body heal itself and fight off bugs and viruses.

Stressful moments have a direct effect on the immune system with many studies showing that constant daily pressure quickly reduces your resistance to a virus or disease. Relaxation techniques such as acupuncture, massage and even a relaxing hobby can all help to keep you calm. The gentle movements of Chi kung or T’ai Chi are also particularly effective against anxiety and stress.

Commonly known as the purple coneflower, this wonder herb contains active ingredients in its roots and leaves that have ant-viral, antibiotic and anti-inflammatory properties. It is thought to help encourage the production of white blood cells and helps speed them along to infected areas. As a result it can help shorten or prevent the course of an acute infection and stop colds or flu developing into more serious conditions such as sinusitis, bronchitis or middle ear infections. 

 Probiotic supplements encourage the growth of friendly bacteria in the body, which help to keep disease-causing organisms at bay. Research has found that if you eat a low-fat Bio yoghurt every day, you're 25 per cent less likely to develop a cold than non-yoghurt eaters - and if you do get a cold, symptoms disappear more quickly. It's thought that the live bacteria in the yoghurt provide protection by producing natural antiviral substances in the body.

The above overview of innate and adptive immunity depicts a miuticomponent interactive system that protects the host from infectious diseases and from cancer.This overview would not be complete without mentioning that the immune system can function improperly.Sometimes the immune system fails to protect the host adequately or misdirect its activities to cause discomfort common manifestations of immune dysfunction:

* Allergy and asthma
* Graft rejection and graft-versus-host disease
* Autoimmune disease
* Immunodeficiency

Allergy and asthma are results of inappropriate immune responses,often to common antigens such as plant pollen,food,or animal dander.The possibility that certain substances increased sensitivity rather than protection was recognized in about 1902 by Charles Richet,who attempted to immunize dogs against the toxins of a type of jellyfish,physalia.He and his colleague Paul Portier observed that instantly,and fatally,to subsequent challenge with minute amounts of the toxin.Richet concluded that a succesful immunization or vaccination results in phylaxis,or protection,and that an opposite result may occur- anaphylaxis-in which exposure to antigen can result in a potentially  lethal sensitivity to the antigen if the exposure is repeated.Richet recieved the Nobel Prize in 1913 for his discovery of the anaphylactic response.
Fortunately,most allergic reactions in humans are not rapidly fatal.A specific allergic or anaphylactic response usually involves one antibody type,called IgE.Binding of IgE to its specific antigen (allergen) releases substances that cause irritation and inflamation.When an allergic individual is exposed to an allergen,symptoms may include sneezing,wheezing,and difficulty in breathing(asthma);dermatitis or skin eruptions(hives);and,in more extreme cases,strangulation due to blockage of airways by inflammation.A significant fraction of our health resources is expended to care for those suffering from allergy and asthma.The frequency of allergy and asthma in the United States place these complaints among the most common reason for a visit to doctor's office or to the hospital emergency room.
When the immune system encounters foreign cells or tissue,it responds strongly to rid the host of the invaders.However,in some cases,the transplantation of cells or an organ from another individual,although viewed by the immune system as a foreign invasion,may be the only possible treatment for disease.For example,it is estimated that more than 60,000 persons in the United States alone could benefit from a kidney transplant.Because the immune ayatem will attack and reject any transplanted organ that it does not recognize as self,it is a serious barrier to this potentially life-saving treatment.An additional danger in transplantation is that any transplanted cells with immune function may view the new host as nonself and react against it.This reaction,which is termed graft-versus-host-disease, can be fatal.The rejection reaction and graft -versus-host disease can be suppressed by drugs,but this type of treatment suppresses all immune functions,so that the host is no longer protected by its immune system and becomes susceptible to infectiuuos diseases.Transplantation studies have played a major role in the develpoment of immunology..
In certain individuals,the immune system malfunctions by losing its sense of self and nonself,which permits an immune attack upon the host .This condition, autoimmunity, can cause a number of chronic debilitating diseases.The symptoms of autoimmunity differ depending on which tissues and organs are under attack.

Comparative immunity|Immune system|Immunity|Immunology.

Posted by Mumtaz khan Monday, 12 March 2012 0 comments

Comparative Immunity:
               The field of immunology is concerned mostly with how innate and adaptive mechanisms collaborate to protect vertebrates from infection.Although many cellular and molecular actors have important roles,antibodies and lymphocytes are considered to be the principal players .Yet despite their prominence in vertebrate immune systems,it would be a mistake to conclude that these extraordinary molecules and versatile cells are essential for immunity.In fact, determinants search for antibodies,T cells,and B cells in organisms of the non vertebrate phyla has failed to find them.The interior spaces of organisms as diverse as fruit flies,cockroaches,and plants do not contain unchecked microbial populations,however,which implies that some sort of immunity exists in most,possibly all,multicellular organisms,including those with no components of adaptive immunity.
            A major difference between adaptive and innate immunity is the rapidity of the innate immune response,which utilizes a pre-existing but limited repertoire of responding components.Adaptive immunity compensates for its slower components.Adaptive immunity compensates for its slower onset by its ability to recognize a much wider repertoire of foreign substances,and also by its ability to improve during a response,whereas innate immunity remains constant.It may also be noted that secondary adaptive responses are considerably faster than primary responses.Principle characteristics of the innate and adaptive immune systems.
            Insects and plants provide particularly clear and dramatic examples of innate immunity that is not based on lymphocytes.The invasion of the interior body cavity of the fruit fly ,Drosophila melanogaster,by bacteria or molds triggers the synthesis of small peptides that have strong antibacterial or anti-fungal activity.The effectiveness of these antimicrobial peptides is demonstrated by the fate of mutants that are unable to produce them.For example,a fungal infection overwhelms a mutant fruit fly that is unable to trigger the synthesis of drosmycin, an antifungal peptide.Further evidence for immunity in the fruit fly is given by the recent findings that cell receptors recognizing various clases of microbial molecules were first found in Drosophila.
                 Plants respond to infection by producing a wide variety of antimicrobial proteins and peptides,as well as small nonpeptide organic molecules that have antibiotic activity.Among these agents are enzymes that digest microbial cell walls,peptides and a protein that damages microbial membranes,and the small organic molecules phytoalexins.The importance of the phytoalexinsis shown by the fact that mutations that alter their biosynthetic pathways result in loss of resistance to many plant pathogens goes beyond this chemical assault to include in the infected area  by strengthening the walls of surrounding cells.

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Antigenic Determinants on Immunoglobulins:
         Since antibodies are glycoproteins,they can themselves function as potent immunogens to induce an antibody response.Such anti-Ig antibodies are powerful tools for the study of B-cell development and humoral immune responses.The antigenic determinants,or epitopes,on immunoglobulin molecules fall into three major categories:isotypic,allotypic,and idiotypic determinants,which are located in characteristic portions of the molecule.
         Isotype determinants are consonant-region determinants that collectively define each heavy-chain class and sub class and each light-chain type and subtype within a species.Each isotype is encoded by a separate consonant region gene,and all members of a species carry the same consonant-region genes(which may include multiple alleles).Within a species,each normal individual will express all isotypes.Therefore,when an antibody from one species,each normal individual will express all isotypes in the serum.Different species inherit different constant-region genes and therefore express different isotypes.Therefore,when an antibody from one species is injected into another species,the isotypic determinants will be recognized as foriegn,inducing an antibody response to the isotypic determinants on the foriegn antibody.Anti-isotype antibody is routinely used for research purposes to determine the class or subclass of serum antibody produced during an immune response or to characterize the class of membrane-bound antibody present on B cells.
           Although all members of a species inherit the same set of isotype genes,multiple alleles exist for some of the genes.These alleles encode subtle amino acid differences,called allotypic determinants displayed by an antibody determines its allotypes.In humans,allotypes have been characterized for all IgG subclasses,for one IgA subclass,and for the light chain.The gamma chain allotypes are referred to as Gm markers.At least 25 different Gm allotypes have been identified;they are designated by the class and subclass followed by the allele number,for example,G1m(1),G2m(23),G3m(11),G4m(4a). Of the two IgA subclasses,only the IgA2 subclass has allotypes,as A2m(1) andA2m(2). The light chain has three allotypes.Each of these  allotypic determinants represents differences in one to four amino acids that are encoded by different alleles.
         The unique amino acid sequence of the Heavy and light domains of a given antibody can function not only as an antigen-binding site but also as a set of antigenic determinants.The idiotypic determinants arise from the sequence of the heavy and light chain variable regions.Each individual antigenic determinant of the variable region is referred to as an idiotope.In some cases an idiotope maybe the actual antigen-binding site,and in some cases an idiotope may comprise variable region sequences outside of the antigen-binding site.Each antibody will present multiple idiotopes;the sum of the individual idiotopes is called idiotype of the antibody.
Because the antibodies produced by individual B cells derived from the clone have identical variable-region sequences,they all have the same idiotype.Anti-idiotype antibody is produced by injecting antibodies that have minimal variation in their isotypes and allotypes ,so that the idiotypic differences can be recognized.Often a homogenous antibody such as myeloma protein or monoclonal antibody is used.Injection of such an antibody into a recipient who is genetically identical to the donor will result in formation of anti-idiotype antibody to the idiotypic determinants.

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