Medavar for the discovery of immunological tolerance, in 1972
Although in the middle of the century it was known that a person who fell ill with smallpox did not get it for the second time, only Jenner in the late 18th century proved it experimentally. Pasteur extended https://123helpme.me/write-my-lab-report/ this provision to other infections only 80 years later, but the first acceptable theory of immunity was formulated by Erich even later – in 1900.
With the discovery in the blood of antibodies – protective humoral substances began the second stage of development of immunology (humoral immunology).
In the early 20th century, Ehrlich developed a humoral theory of immunity, according to which the main protective factor is antibodies. In 1902 Richet, Portier discovered the phenomenon of anaphylaxis, in 1903 Arthus – the phenomenon of Arthus (immunocomplex pathology).
The period from 1910 to 1940 was a period of serology. At this time, a statement was formulated about the specifics and that blood pressure is a natural, highly variable globulins. Landsteiner’s work played a bigger role here, concluding that the specificity of blood pressure is not absolute.
From 1905 there were works (Carrel, Guthrie) on organ transplantation. In 1930. K. Landsteiner discovers blood groups (antigens). Failures in transplantation were explained in 1945, when P. Medavar showed that the rejection of genetically foreign tissues is based on the same mechanisms as in anti-infective immunity. There was a new understanding of the functions of the immune system / IP /: the immune system has become a kind of “guardian of order” responsible for the genetic stability of the organism.
Many other scientists have studied that in some infectious diseases (tuberculosis, typhoid fever, mycoses, etc.) there may be incomplete phagocytosis, in which pathogens are absorbed by phagocytes, but do not die or digest, and in some cases even multiply. The expulsion of phagocytosed microbes (eg staphylococci) is also described.
Phagocytosis occurs more vigorously in the immune system than in the non-immune. Macrophages that carry out phagocytosis are involved in immunological reactions. Reflex activation of phagocytosis and its regulation by mediators has been proved, which indicates the role of the nervous system in phagocytosis. However, there is much evidence that in humans and higher animals, the nervous system is an apparatus of other defense mechanisms that are not associated with phagocytosis.
The excretory function of the respiratory system, kidneys, stomach, intestines, various glands, etc. is also a manifestation of nonspecific resistance and helps to free the body from various harmful factors.
Non-specific factors include protective and adaptive mechanisms, which are called stress (G. Cellier). Stressors can be cold, heat, radiation, pathogens and their toxins, other factors that can irritate the body.
The so-called phenomenon of interference (mutual strengthening or weakening) of bacteria plays a role in the body’s protective reactions. For example, it has been proven that when animals are infected with brucellosis, they develop immunity to anthrax bacilli.
There are antibacterial and antitoxic, antiviral and anti-parasitic forms of immunity (depending on which agents the body’s defenses are directed against). However, it should be borne in mind that completely autonomous forms of immunity do not exist, they are all interconnected and have their effect in the body with the participation of all its systems.
In infectious diseases caused by pathogenic bacteria, antibacterial immunity is formed. In the blood and lymphoid-macrophage system, bacteria are exposed to cellular and humoral factors. The state of immunity, in which the body is completely free of the pathogen, is called sterile immunity. In tuberculosis and other infections that have a long course, the relative immunity coincides for a certain period of time with the presence of infectious agents in the body. This immunity is called non-sterile.
Immunity that is produced in the body in response to the release of exotoxins by pathogenic microbes is called antitoxic. Thus, in the process of evolution of protective reactions, the body has developed the ability to neutralize not only microbes but also their poisons – toxins.
In viral infections, the body directs all its defenses to neutralize the virus and neutralize its toxins. Antiviral protective reactions of the body are divided into nonspecific and specific. An integral part of the first is interferon – an inducible protein, discovered in 1957. It can withstand low temperatures, heat and ultraviolet radiation, does not lose activity under the action of acids and alkalis, non-toxic, formed by the lymphatic system and cells.
Interferons are synthesized by UIITO and UIUO in response to natural (viruses, endotoxins, intracellular parasites) and synthetic (high- and low-molecular-weight) inducers. Interferon acts on the intracellular stages of reproduction of a wide range of RNA and DNA-containing viruses, inhibiting the translation of viral messenger RNA and their biosynthesis.
It is proved that interferon derepresses the gene for antiviral protein, which is localized in the cells of the human body on chromosome 21, the reproduction of the virus is not interferon itself, but antiviral protein, the synthesis of which in cells is induced by interferon (FI Ershov, AS Novokhatsky, 1980).
Specific cellular protection of the body is associated with the participation of sensitized T-lymphocytes, which do not act on the virus, and with the help of lymphotoxins destroy virus-infected cells.
Immunity of the organism to pathogenic parasites (malarial plasmodia, trypanosomes, etc.) is called anti-parasitic immunity. The development of such immunity depends on the location of the parasite. This form of immunity is due to the protective effect and increased activity of phagocytes.
In addition to the above forms of protection, there are concepts of collective (group) immunity, transplant immunity, and so on.
Currently, methods have been developed to create artificial immunity. Active artificial immunity is produced as a result of the introduction into the body of weakened or killed pathogens. This causes a mild form of the disease, during which specific antibodies are formed in the body and the person becomes immune for a long time to the disease against which the vaccine was given. This vaccine is used against polio, tularemia, pertussis and other diseases.
Preventive vaccination plays an important role in the fight against infectious diseases.
Passive immunity is created by the introduction into the body of therapeutic sera containing ready-made antibodies against pathogens. This immunity persists for several months.
Therapeutic sera are extracted from the blood of animals (usually horses), which are gradually injected with increasing doses of infectious material. Antibodies accumulate in the animal’s blood. Periodically, such blood is taken and made into medical serum.
Nobel Prizes in Immunology
The Nobel Prizes were awarded to:
in 1901 to E. Bering for the therapeutic use of antitoxic sera, in 1905 to R. Koch for research in the field of bacteriology (tuberculosis), in 1908 to I. Mechnikov and I. Ehrlich for the discovery of phagocytosis, antibodies. (cellular and humoral theories of immunity), in 1919 J. Borde for the discovery of the complement system, research in immunology and bacteriology, in 1930 K. Landsteiner for the discovery of blood groups (antigens), in 1960 M. Burnett and P . Medavar for the discovery of immunological tolerance, in 1972 to R. Porter and D. Edelman for deciphering the structure of antibodies “in 1977 to R. Yelov for the development of a radio-immunological method, in 1980 to B. Benacerraf, J . Dosse and D. Snell for the discovery of antigens of the HLA system., In 1984 G. Keller and C. Milstein for the development of a method for obtaining hybrids,
The development of hybridoma technology for obtaining highly homogeneous antibody drugs has led to the emergence of modern biotechnology:
in 1904 N. Erne for the theory of regulation of immunity, in 1987 S. Tonegawa for genetic control of a variety of antibodies.
Currently, the revolution in immunology continues.
Conclusions. It has been known since ancient times that a human or animal organism that has suffered from an infectious disease almost never gets sick again. With the development of microbiology, it was also found that the penetration of the infectious agent into the body does not always lead to disease. It depends on many reasons and first of all on a condition of an organism. Under normal conditions, the body shows active specific resistance against a particular type of infection.
The state of the organism in which it resists the harmful effects of pathogenic microbes, their toxins or any other foreign bodies, called immunity (from the Latin immunity – release). The outstanding domestic scientist II Mechnikov assigned the main role in innate and acquired immunity to infections to the organism and its specific cells – phagocytes. “Immunity to infectious diseases,” he wrote, “should be understood as a general system of phenomena by which the body can withstand the onslaught of pathogenic microbes.”
Cellular immunity – anti-infective protection, which is carried out by special cells that are in the body.
Immunity (Latin immunitas – release) – a manifestation aimed at maintaining the stability of the internal environment of the body’s protective reactions against genetically foreign substances (antigens).
If the antigens are microorganisms or toxins, infectious, or antitoxic, immunity develops; when transplanting foreign cells, tissues and organs – transplant immunity; in response to tumors – antitumor immunity, etc.
Biology. Manual. – K., 2002. Vorobiev AA Microbiology and immunology. M., 1999. Outstanding scientists of Ukraine. – K., 2001. Vikerchyk KM Microbiology with the basics of virology. – K., 2001.
Features of higher nervous activity in adolescents and the elderly. Abstract
The abstract provides information on the features of higher nervous activity in adolescents and the elderly
Higher nervous activity – a set of reflexes that provide various (most perfect) forms of relationship between animals and humans with the environment and are carried out with the participation of higher parts of the CNS (cerebral cortex, subcortex).