Limits...
NF-kappa B RelA-deficient lymphocytes: normal development of T cells and B cells, impaired production of IgA and IgG1 and reduced proliferative responses.

Doi TS, Takahashi T, Taguchi O, Azuma T, Obata Y - J. Exp. Med. (1997)

Bottom Line: However, the secretion of IgG1 and IgA was reduced in RelA-deficient B cells.Furthermore, both T and B cells lacking RelA showed marked reduction in proliferative responses to stimulation with Con A, anti-CD3, anti-CD3 + anti-CD28, LPS, anti-IgM, and PMA + calcium ionophore.The results indicate that RelA plays a critical role in production of specific Ig isotypes and also in signal transduction pathways for lymphocyte proliferation.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, Aichi Cancer Center Research Institute, Nagoya, Japan.

ABSTRACT
To investigate the function of NF-kappa B RelA (p65), we generated mice deficient in this NF-kappa B family member by homologous recombination. Mice lacking RelA showed liver degeneration and died around embryonic day 14.5. To elucidate the role of RelA in lymphocyte development and function, we transplanted fetal liver cells of 13.5-day embryos from heterozygote matings into irradiated SCID mice. Within 4 weeks, both T and B cells had developed in the SCID mice receiving relA-/- fetal liver transplants, similar to the relA+/+ and +/- cases. T cells were found to mature to Thy-1+/TCR alpha beta +/CD3+/CD4+ or CD8+, while B cells had the ability to differentiate to IgM+/B220+ and to secrete immunoglobulins. However, the secretion of IgG1 and IgA was reduced in RelA-deficient B cells. Furthermore, both T and B cells lacking RelA showed marked reduction in proliferative responses to stimulation with Con A, anti-CD3, anti-CD3 + anti-CD28, LPS, anti-IgM, and PMA + calcium ionophore. The results indicate that RelA plays a critical role in production of specific Ig isotypes and also in signal transduction pathways for lymphocyte proliferation.

Show MeSH

Related in: MedlinePlus

Cells in apoptosis during the course of proliferation assays.  Spleen cells from mice transplanted with relA+/− or −/− fetal liver cells  were stimulated with various mitogens as in Table 2. The percentages of  apoptotic cells were determined using the TUNEL technique with a  FACScan® (32, 33). The numbers of viable cells were determined by the  trypan blue exclusion test. At the beginning of stimulation, no cells were  in apoptosis. The averages and SD values from three independent experiments are shown in the figure.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2196168&req=5

Figure 7: Cells in apoptosis during the course of proliferation assays. Spleen cells from mice transplanted with relA+/− or −/− fetal liver cells were stimulated with various mitogens as in Table 2. The percentages of apoptotic cells were determined using the TUNEL technique with a FACScan® (32, 33). The numbers of viable cells were determined by the trypan blue exclusion test. At the beginning of stimulation, no cells were in apoptosis. The averages and SD values from three independent experiments are shown in the figure.

Mentions: To further analyze the role of RelA in lymphocyte activation, spleen cells from mice transplanted with relA−/− fetal liver cells were stimulated with various agents. With both T cell specific stimuli, Con A, anti-CD3 and anti-CD3+ anti-CD28, and B cell–specific stimuli, LPS and anti-IgM, relA−/− spleen cells showed a much lower [3H]thymidine uptake than relA+/+ or +/− spleen cells (Table 2). To test whether this low response of relA−/− spleen cells is due to reduced cellular proliferation or to increased apoptotic cell death, the percentages of cells in apoptosis during the course of proliferation assays were determined. As shown in Fig. 7, the percentages and the actual numbers of apoptotic cells with relA−/− were not significantly different from the relA+/− case. Although the number of viable cells may not be as indicative as [3H]thymidine uptake because only a small component of the spleen cells can proliferate in response to certain mitogenic stimuli, relA−/− yielded constantly fewer viable cells than relA+/−. These results indicate that RelA-deficient lymphocytes indeed have an impaired proliferative response to various mitogens. As the production of IL-2 and the expression of IL-2Rα were normal in RelA-deficient T cells, the results suggested that RelA is also involved in yet unidentified critical steps of proliferative responses. Furthermore, RelA-deficient lymphocytes exhibited impaired responses to various stimuli whose signals are transduced by distinctive pathways (42, 43). Thus, RelA may be involved in each single pathway or in a critical merging step downstream of these different pathways. Identification of RelA responsive genes involved in proliferation should reveal the role of RelA in these responses. T and B cells of c-Rel–deficient mice have also been found to demonstrate a defective proliferation response to various stimuli, generally with severe reduction (12). These results indicate that RelA and c-Rel are essential for certain steps of proliferation and that they cannot compensate for each other. It is interesting to note that relA−/− lymphocytes showed an impaired proliferative response to PMA+calcium ionophore in this study while c-rel−/− lymphocytes respond normally to this agent (12). Presumably, the involvement of RelA in proliferative responses is thus wider. Furthermore, relA−/− embryonic fibroblasts also showed reduced proliferation after PMA+ calcium ionophore stimulation, down to 30% of the levels of their relA+/+ or +/− counterparts (data not shown). As expression of relA is not restricted to lymphocytes, in contrast to that of c-rel (44), this also suggests a role in a wider range of biological processes.


NF-kappa B RelA-deficient lymphocytes: normal development of T cells and B cells, impaired production of IgA and IgG1 and reduced proliferative responses.

Doi TS, Takahashi T, Taguchi O, Azuma T, Obata Y - J. Exp. Med. (1997)

Cells in apoptosis during the course of proliferation assays.  Spleen cells from mice transplanted with relA+/− or −/− fetal liver cells  were stimulated with various mitogens as in Table 2. The percentages of  apoptotic cells were determined using the TUNEL technique with a  FACScan® (32, 33). The numbers of viable cells were determined by the  trypan blue exclusion test. At the beginning of stimulation, no cells were  in apoptosis. The averages and SD values from three independent experiments are shown in the figure.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196168&req=5

Figure 7: Cells in apoptosis during the course of proliferation assays. Spleen cells from mice transplanted with relA+/− or −/− fetal liver cells were stimulated with various mitogens as in Table 2. The percentages of apoptotic cells were determined using the TUNEL technique with a FACScan® (32, 33). The numbers of viable cells were determined by the trypan blue exclusion test. At the beginning of stimulation, no cells were in apoptosis. The averages and SD values from three independent experiments are shown in the figure.
Mentions: To further analyze the role of RelA in lymphocyte activation, spleen cells from mice transplanted with relA−/− fetal liver cells were stimulated with various agents. With both T cell specific stimuli, Con A, anti-CD3 and anti-CD3+ anti-CD28, and B cell–specific stimuli, LPS and anti-IgM, relA−/− spleen cells showed a much lower [3H]thymidine uptake than relA+/+ or +/− spleen cells (Table 2). To test whether this low response of relA−/− spleen cells is due to reduced cellular proliferation or to increased apoptotic cell death, the percentages of cells in apoptosis during the course of proliferation assays were determined. As shown in Fig. 7, the percentages and the actual numbers of apoptotic cells with relA−/− were not significantly different from the relA+/− case. Although the number of viable cells may not be as indicative as [3H]thymidine uptake because only a small component of the spleen cells can proliferate in response to certain mitogenic stimuli, relA−/− yielded constantly fewer viable cells than relA+/−. These results indicate that RelA-deficient lymphocytes indeed have an impaired proliferative response to various mitogens. As the production of IL-2 and the expression of IL-2Rα were normal in RelA-deficient T cells, the results suggested that RelA is also involved in yet unidentified critical steps of proliferative responses. Furthermore, RelA-deficient lymphocytes exhibited impaired responses to various stimuli whose signals are transduced by distinctive pathways (42, 43). Thus, RelA may be involved in each single pathway or in a critical merging step downstream of these different pathways. Identification of RelA responsive genes involved in proliferation should reveal the role of RelA in these responses. T and B cells of c-Rel–deficient mice have also been found to demonstrate a defective proliferation response to various stimuli, generally with severe reduction (12). These results indicate that RelA and c-Rel are essential for certain steps of proliferation and that they cannot compensate for each other. It is interesting to note that relA−/− lymphocytes showed an impaired proliferative response to PMA+calcium ionophore in this study while c-rel−/− lymphocytes respond normally to this agent (12). Presumably, the involvement of RelA in proliferative responses is thus wider. Furthermore, relA−/− embryonic fibroblasts also showed reduced proliferation after PMA+ calcium ionophore stimulation, down to 30% of the levels of their relA+/+ or +/− counterparts (data not shown). As expression of relA is not restricted to lymphocytes, in contrast to that of c-rel (44), this also suggests a role in a wider range of biological processes.

Bottom Line: However, the secretion of IgG1 and IgA was reduced in RelA-deficient B cells.Furthermore, both T and B cells lacking RelA showed marked reduction in proliferative responses to stimulation with Con A, anti-CD3, anti-CD3 + anti-CD28, LPS, anti-IgM, and PMA + calcium ionophore.The results indicate that RelA plays a critical role in production of specific Ig isotypes and also in signal transduction pathways for lymphocyte proliferation.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, Aichi Cancer Center Research Institute, Nagoya, Japan.

ABSTRACT
To investigate the function of NF-kappa B RelA (p65), we generated mice deficient in this NF-kappa B family member by homologous recombination. Mice lacking RelA showed liver degeneration and died around embryonic day 14.5. To elucidate the role of RelA in lymphocyte development and function, we transplanted fetal liver cells of 13.5-day embryos from heterozygote matings into irradiated SCID mice. Within 4 weeks, both T and B cells had developed in the SCID mice receiving relA-/- fetal liver transplants, similar to the relA+/+ and +/- cases. T cells were found to mature to Thy-1+/TCR alpha beta +/CD3+/CD4+ or CD8+, while B cells had the ability to differentiate to IgM+/B220+ and to secrete immunoglobulins. However, the secretion of IgG1 and IgA was reduced in RelA-deficient B cells. Furthermore, both T and B cells lacking RelA showed marked reduction in proliferative responses to stimulation with Con A, anti-CD3, anti-CD3 + anti-CD28, LPS, anti-IgM, and PMA + calcium ionophore. The results indicate that RelA plays a critical role in production of specific Ig isotypes and also in signal transduction pathways for lymphocyte proliferation.

Show MeSH
Related in: MedlinePlus