Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A previously undefined phenotype of CD8(+) cells that appears to represent in vivo activated CTL precursors (CTLP*) has been identified in the spleens of C57Bl/6 mice responding to a P815 tumor allograft. This population was first evident by the transient expression of very high levels of CD28 and CD44 on day 5 of the allograft response and reached maximal levels on days 7 and 8 before declining on day 9. A transient increase in CD69 expression was also observed on these cells on day 5. In contrast, CTL effectors (CTLE), identified by their CD8(+)CD44(hi)CD62LloCD45RBlo phenotype, were not appreciably detected in the spleen until day 8 and reached maximal levels on day 10. Further characterization of CTLP* on day 7 revealed that they represented blasting cells by increased light scatter and also expressed very high levels of CD54 but not CD122, CD152, or CD154. In addition, the cells had already up-regulated CD49d, asialo GM1, CD11a, and CD95L, and down-regulated their expression of CD62L. A small percentage of these cells also expressed CD25. Day 7 CTLP* sorted on the basis of their CD44(xhi) and CD54(xhi) phenotype did not exhibit cytolytic activity in a standard chromium release assay but became cytotoxic when they were cultured in the presence of exogenous murine IL-2 for 5 days. Granzyme B activity, however, was detected in CTLP* on day 7 at levels equivalent to CTLE on day 10. In order to establish a potential precursor relationship between CTLP* and CTLE, mice were treated with various doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a chemical that has been shown to dose-dependently suppress the in vivo generation of CTLE to P815 tumor cells by altering an early stage of CTLP activation. Results indicated that CTLP* were suppressed by TCDD on day 7 to the same degree that CTLE were suppressed on day 10. Importantly, for controls and for all doses of TCDD, there were approximately 12.5 CTLE on day 10 for every CTLP* detected on day 7. These results suggested that TCDD acted identically across all doses to inhibit the early stages of activation of CTLP but did not affect the final stages of differentiation and expansion to CTLE. This interpretation supports the previous observation that TCDD exposure had to occur within the first 3 days of the allograft response in order to induce suppression of CTLE activity. Taken together, these results support the conclusion that in vivo activated CTLP can be identified by their unique expression of very high levels of CD44, CD28, and/or CD54 prior to their full maturation and clonal expansion to functional CTLE.
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PMID:Novel phenotype associated with in vivo activated CTL precursors. 1007 61

T cell development and function in complex ganglioside-lacking (GM2/GD2 synthase gene-disrupted) mice were analyzed. GM1, asialo-GM1, and GD1b were representative gangliosides expressed on T cells of the wild type mice and completely deleted on those of the mutant mice. The sizes and cell numbers of the mutant mice spleen and thymus were significantly reduced. Spleen cells from the mutant mice showed clearly reduced proliferation compared with the wild type when stimulated by interleukin 2 (IL-2) but not when treated with concanavalin A or anti-CD3 cross-linking. Expression levels of IL-2 receptor alpha, beta, and gamma were almost equivalent, and up-regulation of alpha chain after T cell activation was also similar between the mutant and wild type mice. Activation of JAK1, JAK3, and SAT5 after IL-2 treatment was reduced, and c-fos expression was delayed and reduced in the mutant spleen cells, suggesting that the IL-2 signal was attenuated in the mutant mice probably due to the modulation of IL-2 receptors by the lack of complex gangliosides.
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PMID:Attenuation of interleukin 2 signal in the spleen cells of complex ganglioside-lacking mice. 1031 76

To analyze the mechanisms by which cancer cells escape from hosts' immune surveillance, we investigated the changes in immune status during the progression of leukemia induced by injecting mice with WEHI-3B cells. In the bone marrow (BM) of leukemic mice, only DX5(+)CD3(-) cells were continuously increased, despite the progression of leukemia. In addition, DX5(+)CD3(-) cells were rapidly increased in peripheral blood (PB) 20 days after inoculation. We also found that myeloid dendritic cells (DCs) expressing low levels of I-A(d) and having low allo-T cell stimulatory activity were markedly increased in PB and spleen. The increase in DX5(+) cells in BM was thought to be induced by soluble factors from leukemic cells. DX5(+) cells from leukemic mice were CD3(-), B220(-), Gr-1(-), CD14(-), CD94(-), Ly-49C/F(-), asialo GM1(+), CD25(+), CD122(+), Thy-1(bright), and c-kit(dim) and showed low killing activity against YAC-1 cells, suggesting that those DX5(+) cells were immature NK cells. NK cells from leukemic PB down-regulated the expression of I-A(d) on DCs, an effect mediated by TGF-beta. Moreover, these NK cells significantly suppressed the allo-T cell stimulatory activity of DCs, an effect requiring cell-to-cell contact between NK cells and DCs and thought to involve CD25. Importantly, NK cells from leukemic PB inhibited generation of autotumor-specific CTL induced by DCs in primary MLR or by DC immunization. In conclusion, we identified circulating immature NK cells with immunosuppressive activities. These cells may be important for understanding the involvement of the host immune system during the development of leukemia.
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PMID:Immature NK cells suppress dendritic cell functions during the development of leukemia in a mouse model. 1654 47

The contribution of tumor associated macrophage (TAM) to the induction of major histocompatibility complex (MHC) class I expression in vivo has not been reported precisely. In this study, we utilized Interleukin-2 (IL-2) cDNA-introduced B16 melanoma cells (B16/IL-2) and vehicle-alone control cells (B16/mock) to examine whether TAM could contribute to the induction of MHC class I on B16 cells in vivo. Interestingly, although B16/mock and B16/IL-2 did not express MHC class I in vitro, MHC class I was strongly expressed in vivo in B16/IL-2 in comparison to B16/mock. Although in vivo treatment of anti-NK1.1 antibody abolished MHC expression in B16/mock in vivo, the same treatment did not influence MHC expression in B16/IL-2. Interestingly, both anti-asialo GM1 and anti-CD11b treatment strongly decreased MHC expression in B16/IL-2. TAM expressed both asialo GM1 and CD11b antigen, and TAM recovered from B16/IL-2 produced interferon gamma (IFNgamma) 6 times more than that from B16/mock. In addition, TAM recovered from B16/IL-2 secreted 33.64 times more IFNgamma in response to in vitro administration of IL-2. Therefore, we checked whether or not IL-2 could influence the expression of IL-2 receptors. TAM recovered from IL-2 expressed middle affinity receptor of IL-2 (CD122 and CD132) while that from B16/mock expressed low affinity receptor (CD25 and CD132). Finally, we observed that B16 cells became apoptotic with IFNgamma treatment in vitro. These results suggested that IL-2 augmented activation of TAM would play the main role in induction of the MHC class I molecule through secretion of IFNgamma, and would contribute to the IFNgamma-mediated apoptosis induction in tumor cells.
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PMID:Interleukin-2 augmented activation of tumor associated macrophage plays the main role in MHC class I in vivo induction in tumor cells that are MHC negative in vitro. 1659 36


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