Immunology is the branch of biology that deals with the study of the immune system. Appeared very early in the evolution scale, this system has evolved to discriminate the self of the nonself. The reactions of the body to a pathogen defense – regardless of the nature of it, viruses, bacteria, fungus or Protozoan, autoimmune diseases, allergies, and the rejection of grafts form the medical aspect of this science. Synthesis and maturation of antibodies, mechanisms of activation of the complement system, mobilization and coordination of defence cells, form the fundamental and mechanistic science.
HIV is a virus that causes the AIDS pandemic whose life interferes with the human immune system.
The oldest evidence known to the immunological comments date from 430 BC. On this date, during the typhoid fever epidemic in Athens during the Peloponnesian War, the historian Thucydides note that only those who have already supported and survived the infection were capable of caring for the sick.
Around 6000 BC, there is in China the practices of voluntary transmission of smallpox for prevention. This technique, called “inoculation”, is to collect pus on a little patient with the disease to inoculate it with a needle in a healthy subject. This method spread from the 15th century, especially in China, in India and Turkey. Through the wife of the British Ambassador in Constantinople, which he shot his son in this way, the inoculation was known in England to 1722, and then spread throughout Europe in the following years.
At the same time, the campaign doctor Edward Jenner found that the farm in regular contact, in trading, with smallpox of the cow (vaccine or Cowpox), which is harmless to humans, were spared by epidemics of smallpox, then frequent, or showed only weak symptoms. After intensively studying the phenomenon, he took on 14 may 1796, pus on a girl contaminated the cowpox pustule, and injected it to a boy of eight years. After the boy was healed of benign disease induced by the vaccine, Jenner injected him genuine smallpox. The boy also overcame this infection without serious symptoms. From the inoculation, the process of Jenner offered major benefits: persons immunized by the vaccine had no buttons, and typical scar induced by the inoculation. There was no risk of mortality unlike the inoculation; and individuals represented no risk of contagion. Vaccinia virus is the origin of the names of “vaccine” and “vaccination”, and Edward Jenner is today considered the founder of immunology.
Turning points of the 19th century
Another major step in the development of immunology is the design of a vaccine against rabies by Louis Pasteur in 1885. On July 6, 1885, he vaccine Joseph Meister, a nine year old boy who had been bitten two days earlier by a rabid dog. Joseph Meister became the first human being to survive rabies in the history of medicine. In a year, the vaccine was administered to 350 people contaminated, and none died from rabies infection. Two years ago, Robert Koch had discovered the head of tuberculosis, Bacillus that bears his name, and shortly after, the test tuberculin, which allows to demonstrate the TB infection, and based on the immune response. This work served as basis in the work of Calmette and Guérin, who portrayed the Bacillus that bears their name (BCG for Bacillus Calmette-Guérin) and leading to vaccination against tuberculosis. The vaccine against infectious diseases developed from that time. Max Theiler received the Nobel Prize for medicine in 1951 for the development of a vaccine against yellow fever.
In 1888 Emile Roux and Alexandre Yersin discovered the diphtheria toxin. Two years later, Emil Adolf von Behring and Shibasaburo Kitasato highlight an antitoxin in serum of the patients who had survived to diphtheria. Emil von Behring was the first to use these anti-sérums for the management of diphtheria patients. For this work he received in 1901 the Nobel Prize for medicine. The Belgian bactériologue Jules Bordet discovered in 1898 that heat serum above 55 ° C blocks his ability to stick to certain chemical substances. The ability of serum to kill bacteria was also lost. He asked the following assumption: there is a substance, sensitive to heat, for the action of serum on bacteria, in the serum and he named this compound “Alexin.” Ehrlich studied this compound in the following years, and introduced the concept of supplement still used today.
Beginning of the 20th century
In the early 20th century, immunology research takes two distinct directions. Humoral Immunology, of which the key figures were Paul Ehrlich and Emil Adolf von Behring, was assumed that the basis of the defence against infection should be in a substance in the serum, such as the antitoxins. This theory predominated to the early 1900′s and for several decades. In parallel, and from the years 1883/1884, developed the point of view of cellular immunity, which is based on the work of George Nuttall and Ilya Ilyich Mechnikov. Mechnikov was able to prove the involvement and the importance of the action of the cells of the body in the fight against pathogens by studying the action of white blood cells on bacteria. His work on phagocytosis earned him the Nobel Prize in medicine in 1908, together with Paul Ehrlich. As it will be shown later, these two types of phenomena are the two sides of the action of the immune system and the immune response. However, it was not until the 1940s so the hypothesis of cellular immunity is generally recognized, and that the hypothesis that antibodies are the major players of the immune response is abandoned.
In 1901 Karl Landsteiner highlighted the existence of blood groups and by this discovery helped take a new important step in the understanding of the immune system. In 1930 he received the Nobel Prize in medicine. In 1906, Clemens Peter Freiherr von Pirquet observed that patients who he administered the horse serum had a strong reaction to the second injection. He named this hypersensitivity reaction “allergy”. The phenomenon of anaphylaxis was discovered by Charles Robert Richet, who received the Nobel Prize for medicine in 1913 for this. Emil von Dungern and Ludwik Hirszfeld publish in 1910 their research on the transmission of blood groups, and so the initial results on the genetics of a part of the immune system. In this work, they offer the “ABO” nomenclature, which will become an international standard in 1928. In 1917, Karl Landsteiner described the concept of haptens, after to be combined with a protein are able to induce an immune response with specific antibody production. Lloyd Felton succeeded in 1928 the purification of antibodies from the serum. From 1934 to 1938, John Marrack developed the theory of specific recognition of Antigen by an antibody.
By studying the rejection of grafts, Peter Gorer discovered H – 2 mouse Antigen, and thus, without knowing it, the first Antigen of what were then called the complex major histocompatibility (MHC for English major histocompatibility complex). Always by the study of graft rejection, Peter Medawar and Thomas Gibson discovered important functions of immune cells. It is by this work, which was the general acceptance of cellular immunity. In 1948, Astrid Fagraeus discovered that antibodies are produced in blood plasma by B lymphocytes. The following year, Frank Macfarlane Burnet and Frank Fenner published their hypothesis of immunological tolerance, that was posted a few years later by Jacques Miller, who discovered the Elimination of auto-réactifs T cells in the thymus. Burnet and Fenner received the Nobel Prize for medicine in 1960 for their work on tolerance. In 1957, Frank Macfarlane Burnet described the fundamental principle of Adaptive as immunity being clonal selection.
The English Alick Isaacs and Switzerland Jean Lindemann, student infection of cell cultures by viruses, discovered in 1957 that the cells by a virus infection, were largely resistant to another infection by a second virus. A protein that they named interferon they isolated from infected cells. Late 1960s and early 1970s, John David and Barry Bloom discovered the (MIF) macrophage migration inhibitory factor and many other substances secreted by lymphocytes. Dudley world proposed for these substances the name of “lymphokine”. In the 1970s, Stanley Cohen, who received the Nobel Prize in medicine for his discovery of NGF and EGF growth factors, in 1986 began to work with Takeshi Yoshida on the functions of the lymphokines. They uncovered evidence that these substances, produced many different types of cells, were capable of action at a distance, as hormones. Following the many discoveries in this area, Stanley Cohen proposed in 1974 the term “cytokine” that imposed quickly. Meanwhile, more than a hundred different cytokines were identified, and their structures and activities studied in detail.
The sixties are generally considered the beginning of the modern era of immunology. Gerald Edelman and Rodney Porter managed to elucidate the structure of antibodies between 1959 and 1961, and were winners of the Nobel Prize for medicine in 1972. At the same time, Jean Dausset, Baruj Benacerraf and George Snell discovered the complex major histocompatibility, also called system HLA (English Human Leukocyt Antigen) in being human, a discovery which enabled them to receive the Nobel Prize in medicine in 1980. In 1959, Joseph Murray performs the first Allograft by transplanting a kidney. Donnall Thomas, they study artificial immunosuppression that allows tolerance of patients towards their registry; They received the Nobel Prize for medicine in 1990 for these studies. Circa 1960 also, the scientific community discovered, through the work of Jacques Miller, other fundamental characteristics of immune cells, in particular the description of functions and differentiation of B and T lymphocytes. After this breakthrough, the theory that the immunity is divided into one cell part and another humoral is imposed, and the two theories were more set in competition. In the following decades, the different subtypes (called isotypes) antibodies were identified and their respective functions tested. In 1975, Georges Köhler, Niels Kaj Jerne and César Milstein describe the method of production of monoclonal antibodies. This discovery had a major impact on basic research, as well as for the diagnosis and treatment of diseases, and they received the Nobel Prize in medicine in 1984. Other major discoveries were made in the following years: in 1973, Ralph Steinman and Zanzil Cohn discovered dendritic cells. In 1974, Rolf Zinkernagel and Peter Doherty discover the restriction of the presentation of Antigen by molecules of MHC, discovery that won him the Nobel Prize for medicine in 1996. In 1985, Susumu Tonegawa identifies the immunoglobulin genes, and receives the Nobel Prize for this in 1987; the same year, Leroy Hood does the same for the T-cell receptor genes.
Another concept emerged in 1986: the orientation of the immune response. Based on the role of lymphocytes T CD4 +, this concept, developed by Robert Coffman and Tim Mosmann, present the dichotomy between a “Th1″, response directed against cells, which will produce specific cytotoxic lymphocytes, as in the case of cancer or intracellular infection; and a “Th2″ response against a soluble agent, which will produce specific antibodies, as in the case of an extracellular bacteria or a toxin. The Th1/Th2 balance is always an intense field of research.
The concept of tolerance induced by lymphocytes was first described in 1969 by Nishizuka and Sokakura. They had their results on a subpopulation of suppressor T cells able to prevent a reaction to naive lymphocytes. Very controversial, these results will be forgotten until the rediscovery of the phenomenon by Sakaguchi in 1982 under the name of T regulator, currently actively studied subject.
Since the 1950s, the theory that dominates in immunology is the recognition of the “self” and the “nonself” by the Adaptive immune system. However, this model does not adequately explain the phenomena of tolerance of graft rejection, nor the need for presentation of Antigen, and in 1989, Charles Janeway proposed a model that would be the innate immunity which would be the real guardian of the keys to the triggering an immune response. The decision to respond or not to a foreign agent would be based on the recognition of reasons by putative receptors that he called the PRR (for English Pattern Recognition Receptor). This model is extensive from 1994 by Polly Matzinger, which develops the theory of the danger. According Matzinger, the onset of immune response would be on the basis of molecular reasons associated with pathogenic organisms (of English pathogen-associated molecular pattern, PAMP) by the PRR. This model was validated experimentally since by the identification of hazards and some of their ligands receivers.
Today, the proliferation of cytokines, Chemokines, subtypes and cellular markers makes it difficult to have an overview of the field.
Concepts in Immunology
Because of the complexity of the studied phenomena and their intimate imbrication, immunologists are often reduced to use more or less abstract concepts to interpret available information. The wire of time, more and more new ideas, more or less overlapping are in the scientific community, most of the time in between two opposing concepts. The list below may not be exhaustive, but gives an overview of some of these great concepts. It is naturally some points already seen in the history, but develops under a simplified and more pragmatic aspect.
The basic concept of Immunology of the adaptive response is Antigen. Overall, is described as Antigen any substance capable of reacting the Adaptive immune system. In practice and to simplify, this is any substance which the second introduction in the body will produce a different effect of the first. What macromolecules including the presence in the body triggers immune reaction.
Innate or Adaptive
Important concept, that of the innate system and the adaptive system (or acquired, although this term is less and less used). This is to contrast phenomena “nonspecific” to “specific” events, implied “of Antigen.
In the first case, it is a reaction following the introduction of a new element, whatever it may be, and which is based on an overall reaction of a cell type. All cells injured, regardless of the cause, have similar reactions, and immune system cells react in stereotypical ways also. This innate response is fast, without memory, independent of the Antigen. A multitude of situation (injury, infection viral or bacterial, etc.) lead to similar innate reactions.
The adaptive response concerning phenomena linked to antigens, and consists of the selection of clones of lymphocytes, able to identify what is perceived as a threat. This adaptive response is slow, strictly dependent of the Antigen, and has an immune memory. Each different situation will lead to the selection of a few lymphocyte clones that will support the danger.
Cellular or humoral
One of the oldest concepts against a cell component a (“humoral”) soluble component of immunity. It takes the serum, therefore free cell blood and Fibrinogen, can produce fast phenomena and very effective destruction (Lysis) of target organisms, on the one hand and the effects of some immune cells are more difficult to observe, because slower and impose very strict testing conditions. The two types of phenomena were for a long time impossible to observe at the same time. This opposition will no longer be as soon as techniques allow to prove that these are immune cells that produce these soluble factors.
TH1 or Th2
The discovery of the roles of cells CD4 + T helper (Th), namely to assist the immune responses, made fast enough escape an experimental fact: under certain conditions, the Th may promote a response to cell-mediated, with generation of cytotoxic cells, or a humoral response, with production of antibodies. In other words, same antigen in different situations will sometimes cause a response to cell-mediated, sometimes a response to humoral mediation. Repeating the old cell/humoral dichotomy, the Th1/Th2 concept allows against the conditions in which the CD4 + T react by producing signals toward the answer a cell cytotoxicity with cells CD8 + T cytotoxic (CTL for cytotoxic T lymphocytes) in large numbers; or on the contrary the formation of a soluble response, with differentiation of B lymphocytes in plasma cells, producing antibodies in large quantities.
Self or nonself
Cell response was long considered as resulting from a direct recognition by the immune cells of foreign cells. Otherwise how to explain that substances produce a strong reaction in an organism and none in another? The introduction of a foreign element (infection or file) must be followed by an acceptance or a rejection by the immune system. During a skin graft from for example, the skin on the donor was well accepted by the immune system of the donor. However, after the transplantation, the immune system of the recipient may well decide to consider the new skin as foreign, and dismiss it, while it does not constitute a danger. This concept is still very current, although its mechanisms were largely elucidated by the study of the interactions between the CRT and the MHC molecules.
Immunogenic or immunotolerogen
Another question may arise: how is it that some “foreign” bodies are not recognized? The first concept is that of “Central tolerance”, which States that no organization should, at the base, produce auto-réactifs lymphocytes, i.e. lymphocytes response against antigens of the “self”. The second concept is that of peripheral tolerance. It is based on cells that inhibit the responses of other immune cells, and whose action is very plastic. The problem here is therefore to find out under what conditions the introduction of a foreign element of an Antigen, will either generate an immune response, in which case the Antigen is immunogenic, or even produce a tolerance for this antigen. Talking about in this case of substance immunotolerogen.
Dangerous or safe
The danger theory is based on a simple observation: in some situations, a same antigen may be perceived as safe (immunotolerogen), dangerous (immunogenic), and where it is immunogenic, develop very different responses, cellular responses or different antibody responses, up to allergy. The theory of the danger stipulates that it is the conditions under which the Antigen is perceived that determine the type of immune response that will be developed. These conditions involve signals of danger in more or less numerous and more or less large amount, and accompanying the Antigen. The combination of the signals of danger (or their absence) directs the immune response.
Bodies of immunity
- All of the organs of the immune system is called the lymphoid system.
- Primary or central Lymphoid organs
- Bone marrow: this is that the cells of the immune system are produced, by a process called hematopoiesis. It is also the location of the acquisition of the immunocompetence of B lymphocytes.
- Thymus: this is be the maturation and selection of T cells.
Secondary or peripheral Lymphoid organs
At the level of the blood system, there are proteins escapement. These proteins are found in the interstitial fluid and should return to the blood to control its osmolarity. Lymph capillaries recover these proteins and also capture the pathogens, the immune system cells and debris of dead cells. The lymphatic system causes lymph to the level of an integrative centre that corresponds to the lymph nodes. After the passage of lymph in the ganglia, lymph is uncluttered. Lymph flows to the heart in one direction. She joined the blood at the level of the heart by the thoracic duct and empties into the left subclavian vein.
- The lymph nodes have a more or less globose structure. They decompose into several zones.
- A capsular sinus that allows the arrival of afferent lymphatic vessels. Traverse lymph sinus enters the ganglion through spans.
- The cortex of the ganglion is occupied by B lymphocytes. B cells are grouped into clusters. Are these follicles rearing infection.
- The paracortex is home to lymphocytes T and dendritic cells.
- At the centre, there is an output area of B lymphocytes and T lymphocytes. It is the hilum by which out efferent lymphatic vessels.
- The secondary appendages (aggregated lymphoid formations) have specific areas of treatment. It is the ring of Waldeyer crossroads aerodigestive (tonsils and adenoids), Appendix and Peyer’s patches.
- The spleen is also part of the immune system because it purifies blood to pathogens that might be there.
Tertiary Lymphoid organs
Tertiary Lymphoid organs include all tissues and organs where the immune response takes place. They contain little normal lymphoid cells in physiological conditions but can import a large quantity in the presence of a pathogen. They include:
- The respiratory system
- The digestive tract – see lymphoid tissue associated with mucous membranes
- Genital tract – see GALT
- The rest of the body.
It should be noted the existence of immune sanctuaries. What tissue where immune cells enter It’s in the testes and the anterior Chamber of the eye. Naive lymphocytes cannot cross the blood-brain barrier.
- Different types of immune responses
- Humoral immunity
- It is the defense mechanisms involving soluble factors. It is of two types: innate defence and adaptive defense.
- Innate humoral immunity
- The innate defences correspond to molecules present spontaneously in the body and which means the threat. It’s natural antibodies, the defensins, the complement system. Attacked tissues also produce molecules of inflammation, such as tissue factor and arachidonic acid derivatives: leukotrienes and prostaglandins
Adaptive humoral immunity
It is supported by the presence of circulating antibodies. Antibodies are produced by plasma cells, derived from the terminal differentiation of a lymphocyte clone B. They are molecules of immunoglobulin of different types:
IgM that are the first products in infection. They are decavalent and their greed for antigens is very large. They have a major role in the formation of immune complexes.
IgG of high affinity, with a key role in the cytotoxicity related to antibodies.
IgE immediate allergy (type 1 hypersensitivity reaction) media.
IgA secreted at the level of the mucous membranes, play a major role in the neutralization of pathogens on the epithelia (bronchi, gastrointestinal tract).
In General, the antibodies act in two different ways: either by the activation of complement, or by binding of the immune complex on an immune cell with a receptor for the constant fragment antibody (such as macrophages, lymphocytes NK for example)
Cell-mediated immune phenomena involve different types of cell, grouped in two concepts: cells of innate immunity and adaptive immunity.
Cells of the innate immunity
These are cells that are able to respond to a phenomenon without prior education. They react to these stimuli on a variety of pathogens and antigens independently. This is:
- lymphocytes NK.
- formerly called granulocytes, polymorphonuclear;
- dendritic cells, which are the best antigen-presenting cells.
Cells of the adaptive immunity
It comes to reactions involving type T lymphocyte cells. Maturation depends on an antigenic stimulus and education by a cell Antigen presenter. Their activation with a target depends on the presentation of Antigen by the target cell. T lymphocytes are therefore able to recognize transformed cells (i.e. infected by an intracellular pathogen, or a tumor cell). There are two main types of lymphocytes T:
CD8 + lymphocytes recognize an Antigen carried by a molecule of MHC of type I. They usually differentiate into cytotoxic lymphocytes and produce relatively little cytokines;
CD4 + lymphocytes recognize an Antigen carried by a molecule of MHC of type II. Their main action is the secretion of cytokines, which guide and amplify the immune response, this is called the help (in French: aid), hence the nickname given to these lymphocytes T helper. The current paradigm is to differentiate between two types of CD4 +: helpers lymphocytes that moving towards a cytotoxic response (Th1) and those moving towards a more humoral (Th2).
There are also B cells through the diversity of their BCR, which are with AC.
Immunology in practice
- In diagnostic laboratories, and in searching Immunology
Knowledge of immunological mechanisms has enabled the development of many technical qualitative as well quantitative analyses, including using antibodies, vectors, humoral immunity, but also cell tests sometimes. Control of antibody production opened the field to many “affinity” purification techniques, but also therapeutic applications.
Most of these techniques use the properties of monoclonal or Polyclonal Antibody affinity-purified. Their affinity and specificity of their target-binding made them essential tools of detection or capture specific. They determine the presence in a complex sample of an antigen or even one of its particular parts (epitope). Many modalities of implementation exist.
With unlabelled antibody techniques
First proposed analysis techniques using antibodies not marked, for example in precipitation reactions, agglutination reactions (e.g., Coombs test), turbidimetry or nephelometry, and neutralization reactions. It uses the ability to form multiple immune complexes of Antigen target and 2 sites of IgG or IgM 5 sites, and possibly the fact that the antibody is fixed or attaches to cells or particles (agarose). Antigen-antibody complexes become visible macroscopically diffuse manner (opacity by turbidimetry) or local (precipitation), possibly after staining, e.g. to the Coomassie blue.
For example, in several methods say immunoprecipitation (e.g. Ouchterlony), this antibody in a gel immobilized Antigen broadcasting from a well, and it visualizes a representative white line the precipitation of the immune complex. There is a variation using electrophoresis (Fused Rocket Electrophoresis). Other similar techniques are used in research to detect interactions between two proteins or to purify a compound in a solution.
Techniques with marked antibodies
The methods have become more frequent are to use marked antibodies, “detectable” easily, i.e. coupled compounds often fluorescent, or colored gold particles, enzymes that produce a coloured fluorescent or luminescent, signal or small compounds detectable indirectly (biotin, tags), or even of radioactive elements. The ag/ac reaction is implemented in homogeneous or heterogeneous phase. For example this last modality is available in techniques such as ELISA, the blotting or microgrids, depending on whether the medium is a microplate, membrane, glass slide… These analysis in vitro techniques to detect proteins or other molecules, qualitatively (specificity) and/or semi-quantitative (by titration, compared to a titration of standards). ELISA microplate is a very flexible technique, R & D quality control or the screening. According to the specificity of antibodies, can detect small differences or changes between molecules (isoforms protein, phosphorylation, acetylation, etc.). The microarray to qualitatively test hundreds of thousands of molecules (or antibody) on 1 cm² (screening), with two or three parameters (antibody.) Western blot analysis after electrophoresis 2D to distinguish qualitatively and in a same sample quantitatively proteins and their variants (profiling).
Other techniques use the principle of ELISA, but the support is targeted to detect, for example a cell or a virus. For example a section of tissue is “marked immunologically” (the antibody binding), and analyzed with a microscope the cells “stained” by the antibodies (Immuno – Histochemistry (IHC)), or rendered fluorescent (Immuno-Fluorescence (IH) – observed the intensity of fluorescence, its spectral length change (ratiométrie), or the change of polarization of fluorescence (Fluorescence Polarization), or the time between excitation and emission (Life Time Resolved Fluorescence)). Immuno-analyses provide information on the location of antigens, in a cell or tissue, and their relative abundance. A limitation is based on the optical resolution, and the superposition of antigens (in the thickness of the Cup), which is partially addressed by focal scanning (confocal microscopy). In flow cytometry (FCM), it marks cell suspensions, which are analyzed individually, which makes it very powerful information (cell populations, especially multiple detections, as cells can be sorted.)
Immunological analysis (immuno-metric if they are made in quantitative) techniques using labeled antibodies often use systems of str, which is often based on several antibodies, including “secondary” antibodies, marked, and recognizing the “primary” antibodies specific for the target to detect. They may be multiplexed in various techniques (ELISA Fluo, MicroArray, W-Blot, IHF, WCW): 2 and up to 4 specific antibodies labeled differently are used simultaneously, and can then have multiple results on the same sample (at the same time, or after overlay). Variants combine logs to reach up to 48 detections. Other terms and conditions to assess the distance between two molecules (cargo, BRET).
Another property of the antibodies used in animal clinic and for some years in human clinical is the Faculty of some isotypes of antibodies to bind complement, and therefore Lyse the cells on the surface of which they are fixed. In practice, this will destroy the cells with a specific antigen marker (“Lysis” techniques).
Affinity purification techniques use antibodies chemically coupled to resins to capture of Antigen targets (possibly complexed to other partners – nearby immunoprecipitation technique). Applications range from R & D in industry (manufacturing).
The applications of immunological analyses are major in R & D, diagnostic medical and veterinary, and even (food) quality control.
The diagnosis of bacterial infections (e.g. toxoplasmosis) or viral (e.g. HIV, hepatitis B) is based most often on the detection of circulating antibodies in the serum of patients (sometimes in other fluids). The most used technique is the ‘direct’ ELISA.
Direct immunological detection of pathogens
The most used technique is the ELISA with the so-called modality “sandwich” and “inhibition” (or “competition”), in Colorimetry (EIA: enzyme ImmunoAssays) or radiometric, more rarely fluorescence. But also have the flow cytometry for more difficult cases and research hospital, the microgrids that develops to clarify diagnosis with more parameters. Finally immunochemistry (IHC) microscopy is very used to specify the (or in the absence of) diagnostic serological, in hospitals, and even the immunofluorescence (IF). This also applies to cancer (see below).
Immunological detection of biological parameters
Immuno-analysis are capable of some current analyses, and detect normal cell markers (who sign the type this cell, or – receptor, enzyme – activity) or cancer.
Determination of lymphocyte formula makes use of flow cytometry using monoclonal antibodies coupled with specific fluorescent marker molecules (cluster of differentiation CD4/8, etc.).
Dosage of hormones in the serum is often made by ELISA, but some (thyroid hormones including) are by turbidimetry or nephelometry.
The search for cancer of the colon and pancreas is by ELISA with a few common markers (for example CA19-9) tumor markers
Animal Clinic and in recent years in human clinical on use of the Faculty of some isotypes of antibodies to bind complement, and therefore Lyse the cells on the surface of which they are fixed.
Immunology in medical practice
Knowledge of Immunology and immunological techniques are present at many levels in medicine, from diagnosis to the development of vaccines, treatment of autoimmune therapies by registry or using antibodies.
The use of all kinds of vaccines resulted in the triumph of medicine against many infectious diseases. Thus, smallpox is eradicated, and other diseases are candidates for eradication by the immunization: measles, hepatitis B for example. These are diseases caused by viruses which humans is the only reservoir. The vaccination of a large part of the population would eradicate them. These are goals set by the World Health Organization.
Moreover, there is since a vaccine to reduce the risk of cancer of the cervix. This vaccine is directed against a virus responsible for the transformation of epithelial cells of the cervix in tumor cells. Vaccinate girls prior to their first sexual contact would reduce 80% of cervical cancer cases.
Immunology and the study of the immune system is a vital tool for two particular areas: graft rejection and autoimmune diseases, such as diabetes. At the same time, tumor immunology is studying how the immune system interacts with tumor cells, to influence the potential power of the immune response against tumor medically.
Therapeutic side, (“humanized”) modified antibodies are used to convey toxic agents (toxins, radionuclides) to target cancerous cells to destroy tumors (Immuno-therapy). Similarly but for the diagnosis, specific antibodies for tumor markers are marked (fluorescence or low radioactivity (Immunoscintigraphie|))Immuno-Scintigraphie)) and injected into the patient prior to medical imaging to diagnose or locate tumors prior to surgery. For these applications, pointed, finally simply call the importance of traditional immunological techniques for medical, serological or infectious diagnosis including – see above section top technical and applications-.