Unique DNA sequences can be determined directly from mouse genomic DNA. A denaturing gel separates by size mixtures of unlabeled DNA fragments from complete restriction and partial chemical cleavages of the entire genome. These lanes of DNA are transferred and UV-crosslinked to nylon membranes. Hybridization with a short 32P-labeled single-stranded probe produces the image of a DNA sequence "ladder" extending from the 3' or 5' end of one restriction site in the genome. Numerous different sequences can be obtained from a single membrane by reprobing. Each band in these sequences represents 3 fg of DNA complementary to the probe. Sequence data from mouse immunoglobulin heavy chain genes from several cell types are presented. The genomic sequencing procedures are applicable to the analysis of genetic polymorphisms, DNA methylation at deoxycytidines, and nucleic acid-protein interactions at single nucleotide resolution.

https://www.pnas.org/content/pnas/81/7/1991.full.pdf

Genomic sequencing

Publisher Summary Studies of cytotoxicity by human lymphocytes revealed not only that both allogeneic and syngeneic tumor cells were lysed in a non-MHC-restricted fashion, but also that lymphocytes from normal donors were often cytotoxic. Lymphocytes from any healthy donor, as well as peripheral blood and spleen lymphocytes from several experimental animals, in the absence of known or deliberate sensitization, were found to be spontaneously cytotoxic in vitro for some normal fresh cells, most cultured cell lines, immature hematopoietic cells, and tumor cells. This type of nonadaptive, non-MHC-restricted cellmediated cytotoxicity was defined as “natural” cytotoxicity, and the effector cells mediating natural cytotoxicity were functionally defined as natural killer (NK) cells. The existence of NK cells has prompted a reinterpretation of both the studies of specific cytotoxicity against spontaneous human tumors and the theory of immune surveillance, at least in its most restrictive interpretation. Unlike cytotoxic T cells, NK cells cannot be demonstrated to have clonally distributed specificity, restriction for MHC products at the target cell surface, or immunological memory. NK cells cannot yet be formally assigned to a single lineage based on the definitive identification of a stem cell, a distinct anatomical location of maturation, or unique genotypic rearrangements.

Biology of natural killer cells.

Natural killer cells are a recently discovered subpopulation of lymphoid cells that are present in most normal individuals of a range of mammalian and avian species. Natural killer cells have spontaneous cytolytic activity against a variety of tumor cells and some normal cells, and their reactivity can be rapidly augmented by interferon. They have characteristics distinct from other types of lymphoid cells and are closely associated with large granular lymphocytes, which comprise about 5 percent of blood or splenic leukocytes. There is increasing evidence that natural killer cells, with the ability to mediate natural resistance against tumors in vivo, certain virus and other microbial diseases, and bone marrow transplants, may play an important role in immune surveillance.

https://science.sciencemag.org/content/sci/214/4516/24.full.pdf

Natural killer cells: their roles in defenses against disease

Natural cytotoxic activity of peripheral-blood lymphocytes and cancer incidence: an 11-year follow-up study of a general population

Biology and clinical relevance of human natural killer cells.

GERM LINE mutations affecting defined cell populations are often valuable tools in elucidating the function of these cells in complex biological systems such as tumour rejection. We report here that a mutant gene in the mouse called beige (bgJ), leads to a complete and selective impairment of naturally occurring killer lymphocytes, whereas all other forms of cell-mediated lysis are apparently normal. The defective gene product may lie within the lytic pathway subsequent to tumour cell contact. Because many cell types, including natural killer (NK) cells, T cells and macrophages, may be involved in tumour resistance in vivo1, these mice will provide a critical test of the hypothesis that it is NK cells which provide a first line of defence against neoplasia2. It is likely that this mutant will be invaluable for further investigations in tumour immunology just as the nude mouse has been indispensable in evaluating the role of thethymus in the development of the T-lymphoid system and the role of T cells in the rejection of tumours.

The beige mutation in the mouse selectively impairs natural killer cell function.

Immunodeficiency disorders have provided much information on the development and interaction of the various B and T lymphoid components in the immune system of man. As the lymphoid system becomes increasingly divided into functional subsets of cells it will be important to find immunodeficiencies affecting newly discovered cell types. Natural killer (NK) cells are a recently described but ill-defined subpopulation of lymphocytes which is thought to play an important part in surveillance against tumour development. Mice homozygous for the beige gene were found to have a selective deficiency in NK function and were more susceptible to transplantation of syngeneic tumours as predicted. We report here that patients carrying the analogous, autosomal recessive Chediak-Higashi (CH) gene have a profound defect in their ability to spontaneously lyse various tumour cells in vitro by either antibody-dependent or independent mechanisms. Since other cell-mediated cytolytic functions were relatively normal, these results suggest that the beige or Chediak-Higashi gene in both man and mouse controls NK function.

John C. Roder

Papers

The beige mutation in the mouse selectively impairs natural killer cell function.

A new immunodeficiency disorder in humans involving NK cells.