Benacerraf (Benacerraf), Baruch

genus. October 20, 1920
Venezuelan-American geneticist Baruch Benacerraf was born in Caracas (Venezuela), the son of a wealthy merchant of fabrics. His father was an ethnic Jew, Spanish, and his mother - a French Algerian. In 1925, Mr.. family moved to Paris, where she remained until 1939. - World War II. After that, the family returned to Venezuela, and a year later moved to New York. Here B. completed education. After graduating in 1942. comprehensive school at Columbia University, B. entered the Medical College of Virginia. After its completion B. was drafted into the U.S. army, but he was allowed to continue their studies. In 1943, Mr.. He became an American citizen. Two years later he received a medical degree and rank of senior lieutenant of the Medical Service of American armed forces. After serving two years in Nancy (France), B. demobilized.
Since B. childhood asthma, he was interested in the mechanisms of immune hypersensitivity, ie. abnormal reaction of the organism to foreign agents. Many scholars, with whom he consulted, advised him to cooperate with Elvin Kabat, immunohimikom who worked in the Neurological Institute, School of Physicians and Surgeons of Columbia University. Upon receiving the invitation to cooperate Kabat, B. in 1948. began to study the mechanisms of allergy. The following year he accepted an invitation to work in a Paris hospital of Bursa, where he continued immunochemical study.
Despite the fact that the work of B. to examine the functions of leukocytes have been fruitful, he could not get its own laboratory in France, needed to further scientific growth. B. believed that the position of a foreign scientist to block progress in the European scientific community, and therefore, having received an invitation from Lewis Thomas, in 1956, he. returned to the United States and became an assistant professor of pathology in medical school at New York University. Here it is equipped with its own laboratory and again began to research the mechanisms of hypersensitivity, intrigued cellular hypersensitivity. In 1960, Mr.. He became a professor of pathology.
In New York University B. concentrated on the study of cells involved in immune responses - the protective reaction to foreign substances, or antigens. In the early 60-ies. He worked with Gerald M. Edelman, who studied the structure of antibodies formed by the immune system in response to the introduction of antigens. Studies Edelman complicated by the fact that animals of one antigen normally produced by a mixture of different antibodies. B. decided to test, not whether the immunization of animals (in the beginning he conducted experiments on guinea pigs) are very simple synthetic antigens cause the formation of more homogeneous antibody. 'I found - he wrote later - that some animals react [antigen] antibody, but not others'.
It is this fact that has allowed B. establish that the ability to react to certain antibodies are genetically determined. He named the corresponding genes of IR-genes (from Immuneresponse - immune response). In 1965, Mr.. Hugh Makdevit and his colleagues found similar genes in mice and found that they are located in the main histocompatibility complex - MHC (Major Histocompatibility Complex). This complex, first described by George D. Snell in the late 40's., Is a set of closely related genes, called transplant genes, tk. the resulting differences in the antigens of the donor and recipient lead to the rejection of a transplanted organ. MHC complex man, named complex HLA, was detected mainly through the works of Jean Jean Dausset. In 1968. B. and some of his staff moved to the National Institute of Health, where B. was promoted to head of the Laboratory of Immunology. Here he and his colleagues confirmed the data Makdevita using inbred lines of guinea pigs, grown at the National Institute of Allergy and Infectious Diseases.
In 1970. B. taken at the same time as professor of comparative physiology and head of the department of pathology at Harvard Medical School. Two years later, he and his colleagues at Harvard, regardless of group Shrefflera Donald, who worked on similar themes, discovered restriction, depending on the IR-locus - a phenomenon concerning the functions of the two types of lymphocytes - B-and T-cells. These cells play a key role in the ability of the immune system to recognize specific substances of infectious microorganisms and to react with. B-cells produce antibodies that interact with foreign antigens, and T-cells directly respond to foreign cells. Different types of T-cells can destroy tumor cells or infected with viruses and bacteria, as well as enhance or suppress the activity of specific B-cells. Interactions between T-and B-cells restriktiruyutsya (constrained) complex MHC: T-cells influence the formation of antibodies B-cells only if both of these varieties have the same IR-Genes. In 1976. Other researchers have found, . that T-cells can destroy cells infected by viruses, . only if those, . and others have the same transplantation antigens (proteins, . encoded by genes of the complex MHC, . detected, . as mentioned, . Snell and Jean Dausset).,
. It soon became clear that, although the proteins encoded by genes and IR-transplant genes from the viewpoint of chemical structures differ, their functions are closely related
. And both are the product of complex MHC. Products transplantation of genes found on the surface of most cells, called today the molecules of class I, and the products of IR-genes that make up the immune system - the molecules of MHC class II.
. 'Evolutionary role [MHC] restriction, . - Wrote B., . - And the importance of MHC antigens are clear, . if we consider the immune responses to T-cells as mechanisms, . primarily responsible for recognition of 'his' and 'others' material on the surface of cells,
. T-cells must determine that a cell becomes malignant transformation or virus and that, therefore, it must be destroyed '. He suggested, . that the products of MHC class I in infected cells for one reason or another change, and T-cells are specialized in the slightest recognition of such changes, . in particular when a combination of normal class I molecules of the organism from tumor or viral antigens.,
. B
. put forward the hypothesis that this phenomenon may explain why foreign bodies in the transplant so quickly rejected. Fact, . that T-cell recipients respond to class I MHC antigens of the donor (normally slightly different from the antigens of the recipient), . destroying their cells carry the same, . as they destroy cells, . Class I antigens are modified as a result of viral infection or a tumor degeneration.,
. The ability of T-cells regulate the activity of B-cells, like T-cell recognition of infected cells depends on the recognition of the slightest changes MHC products
. It is believed that B-cells T-cells are informed that, with any antigen will react to the antibodies produced by them, 'introducing' this antigen, together with a molecule of class II. Based on the role of these products IR-genes (in humans - antigens HLA-D) in interactions between T-and B-cells, one can assume what the IR-genes involved in immune responses. If a man does not have T cells recognizing a different combination of HLA-D and antigen, this antigen will be for it 'invisible' and the immune response does not occur.
. Growing recognition of the crucial role of MHC in immune responses has led to the award in 1980
. B., Snell and Jean Dausset Nobel Prize in Physiology or Medicine "for their discoveries concerning genetically determined structures on the cell surface that regulate immune responses'. In the congratulatory speech researcher at the Karolinska Institute said George Klein, . that B., . Jean Dausset and Snell 'were able to move at first glance merely a special ground-breaking study on inbred mice in the region, . concerning the most important biological systems, . which plays a pivotal role in studying the mechanisms of recognition of cells, . immune reactions and graft rejection. ",
. Currently Used
. work at Harvard and continues to investigate the genetics and biochemistry of the MHC and its role in T-cells.
In 1943, Mr.. B. married Annette Dreyfus, niece of Jacques Monod, whom he met at Columbia University. Their daughter, Beryl works radiologist. Students and colleagues speak of the B. as a man with 'a sharp, clear thinking'. Lewis Thomas, with whom B. worked at New York University, called it 'astonishing scientists'.
B. awarded Rebbi Xai Shaknai for Research in Immunology and Cancer of the Jewish University in Jerusalem (1974) and Memorial Prize Daketta Jones Foundation, Helen Hay Whitney (1976), as well as honorary degrees of the University of Geneva. He is a member of the National Academy of Sciences of the USA, the American Association of Immunologists. American Society of Experimental Pathology. Society for Experimental Biology and Medicine, the British Association of immunological. French Society of Biological Chemistry. American Academy of Arts and Sciences. He was assistant editor of the American Journal of Pathology '(' American Journal of Pathology ') and' Journal of Experimental Medicine '(' Journal of Experimental Medicine '), . well as a member of the Chief Executives Board Weizmann Institute, . Adviser to the World Health Organization and President Sidney Farber Cancer Institute.,