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Natural killer cell tolerance in mice with mosaic expression of major histocompatibility complex class I transgene.

Johansson MH, Bieberich C, Jay G, Kärre K, Höglund P - J. Exp. Med. (1997)

Bottom Line: The results provide support for selective NK cell tolerance to one particular missing-self phenotype but not to another.We suggest that this tolerance is determined by NK cell interactions with multiple cells in the environment, and that it is dominantly controlled by the presence of cells lacking a specific MHC class I ligand.Furthermore, the tolerant NK cells could be reactivated in vitro, which suggests that the tolerance occurs without deletion of the potentially autoreactive NK cell subset(s), and that it may be dependent upon the continuous presence of tolerizing cells.

View Article: PubMed Central - PubMed

Affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden.

ABSTRACT
We have studied natural killer (NK) cell tolerance in a major histocompatibility complex (MHC) class I transgenic line, DL6, in which the transgene product was expressed on only a fraction of blood cells. In contrast with transgenic mice expressing the same transgene in all cells, NK cells from mosaic mice failed to reject transgene-negative bone marrow or lymphoma grafts. However, they retained the capability to reject cells with a total missing-self phenotype, i.e., cells lacking also wild-type MHC class I molecules. Tolerance against transgene-negative cells was demonstrated also in vitro, and could be broken if transgene-positive spleen cells of mosaic mice were separated from negative cells before, or after 4 d of culture in interleukin-2. The results provide support for selective NK cell tolerance to one particular missing-self phenotype but not to another. We suggest that this tolerance is determined by NK cell interactions with multiple cells in the environment, and that it is dominantly controlled by the presence of cells lacking a specific MHC class I ligand. Furthermore, the tolerant NK cells could be reactivated in vitro, which suggests that the tolerance occurs without deletion of the potentially autoreactive NK cell subset(s), and that it may be dependent upon the continuous presence of tolerizing cells.

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In vitro cytotoxicity  of Dd/Ld-positive and Dd/Ld-negative NK cells from DL6  mice separated on day 4 of IL-2  activation. (A) Dd/Ld-positive  (triangles up) and Dd/Ld-negative  (triangles down) spleen cells from  DL6 mice were separated after 4 d  of culture in the presence of IL-2,  cultured separately for one additional day and subsequently  tested in a chromium release assay  using lymphoblasts from B6,  DL1, and B6 β2m−/− mice as target cells. Effector cells from B6  (circles), DL1 (diamonds), and unseparated DL6 (squares) were  tested in parallel. Target cells are  indicated in the upper right corner of each graph. The figure  shows one representative experiment of two. (B) FACS® analysis  for Dd/Ld expression on the IL-2– activated NK cells used as effector cells in A.
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Figure 7: In vitro cytotoxicity of Dd/Ld-positive and Dd/Ld-negative NK cells from DL6 mice separated on day 4 of IL-2 activation. (A) Dd/Ld-positive (triangles up) and Dd/Ld-negative (triangles down) spleen cells from DL6 mice were separated after 4 d of culture in the presence of IL-2, cultured separately for one additional day and subsequently tested in a chromium release assay using lymphoblasts from B6, DL1, and B6 β2m−/− mice as target cells. Effector cells from B6 (circles), DL1 (diamonds), and unseparated DL6 (squares) were tested in parallel. Target cells are indicated in the upper right corner of each graph. The figure shows one representative experiment of two. (B) FACS® analysis for Dd/Ld expression on the IL-2– activated NK cells used as effector cells in A.

Mentions: To exclude that development of new NK cell clones during the IL-2 culture was responsible for the abrogation of tolerance, we left the DL6 splenocytes unseparated until day 4 of the IL-2 culture, after which Dd/Ld-positive and negative cells were separated. The cells were cultured separately for one additional day in the presence of IL-2 (to allow for the beads to come off), and were then used as effector cells in vitro. These recently separated Dd/Ld-positive cells killed B6-derived lymphoblasts as efficiently as the Dd/Ld-positive cells that were separated already before IL-2 activation (Fig. 7).


Natural killer cell tolerance in mice with mosaic expression of major histocompatibility complex class I transgene.

Johansson MH, Bieberich C, Jay G, Kärre K, Höglund P - J. Exp. Med. (1997)

In vitro cytotoxicity  of Dd/Ld-positive and Dd/Ld-negative NK cells from DL6  mice separated on day 4 of IL-2  activation. (A) Dd/Ld-positive  (triangles up) and Dd/Ld-negative  (triangles down) spleen cells from  DL6 mice were separated after 4 d  of culture in the presence of IL-2,  cultured separately for one additional day and subsequently  tested in a chromium release assay  using lymphoblasts from B6,  DL1, and B6 β2m−/− mice as target cells. Effector cells from B6  (circles), DL1 (diamonds), and unseparated DL6 (squares) were  tested in parallel. Target cells are  indicated in the upper right corner of each graph. The figure  shows one representative experiment of two. (B) FACS® analysis  for Dd/Ld expression on the IL-2– activated NK cells used as effector cells in A.
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Related In: Results  -  Collection

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Figure 7: In vitro cytotoxicity of Dd/Ld-positive and Dd/Ld-negative NK cells from DL6 mice separated on day 4 of IL-2 activation. (A) Dd/Ld-positive (triangles up) and Dd/Ld-negative (triangles down) spleen cells from DL6 mice were separated after 4 d of culture in the presence of IL-2, cultured separately for one additional day and subsequently tested in a chromium release assay using lymphoblasts from B6, DL1, and B6 β2m−/− mice as target cells. Effector cells from B6 (circles), DL1 (diamonds), and unseparated DL6 (squares) were tested in parallel. Target cells are indicated in the upper right corner of each graph. The figure shows one representative experiment of two. (B) FACS® analysis for Dd/Ld expression on the IL-2– activated NK cells used as effector cells in A.
Mentions: To exclude that development of new NK cell clones during the IL-2 culture was responsible for the abrogation of tolerance, we left the DL6 splenocytes unseparated until day 4 of the IL-2 culture, after which Dd/Ld-positive and negative cells were separated. The cells were cultured separately for one additional day in the presence of IL-2 (to allow for the beads to come off), and were then used as effector cells in vitro. These recently separated Dd/Ld-positive cells killed B6-derived lymphoblasts as efficiently as the Dd/Ld-positive cells that were separated already before IL-2 activation (Fig. 7).

Bottom Line: The results provide support for selective NK cell tolerance to one particular missing-self phenotype but not to another.We suggest that this tolerance is determined by NK cell interactions with multiple cells in the environment, and that it is dominantly controlled by the presence of cells lacking a specific MHC class I ligand.Furthermore, the tolerant NK cells could be reactivated in vitro, which suggests that the tolerance occurs without deletion of the potentially autoreactive NK cell subset(s), and that it may be dependent upon the continuous presence of tolerizing cells.

View Article: PubMed Central - PubMed

Affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden.

ABSTRACT
We have studied natural killer (NK) cell tolerance in a major histocompatibility complex (MHC) class I transgenic line, DL6, in which the transgene product was expressed on only a fraction of blood cells. In contrast with transgenic mice expressing the same transgene in all cells, NK cells from mosaic mice failed to reject transgene-negative bone marrow or lymphoma grafts. However, they retained the capability to reject cells with a total missing-self phenotype, i.e., cells lacking also wild-type MHC class I molecules. Tolerance against transgene-negative cells was demonstrated also in vitro, and could be broken if transgene-positive spleen cells of mosaic mice were separated from negative cells before, or after 4 d of culture in interleukin-2. The results provide support for selective NK cell tolerance to one particular missing-self phenotype but not to another. We suggest that this tolerance is determined by NK cell interactions with multiple cells in the environment, and that it is dominantly controlled by the presence of cells lacking a specific MHC class I ligand. Furthermore, the tolerant NK cells could be reactivated in vitro, which suggests that the tolerance occurs without deletion of the potentially autoreactive NK cell subset(s), and that it may be dependent upon the continuous presence of tolerizing cells.

Show MeSH
Related in: MedlinePlus