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Biomedical subjects

S Habu

Publications and source records attributed to S Habu.

At least 127 records · Page 7Linked to original sources
PubMed1989

Lymphocyte infiltration into cerebellum in transgenic mice carrying human IL-2 gene.

We created transgenic mice with an intact human genomic interleukin-2 gene (gIL-2) or a mouse metallothionein-I promoter-human IL-2 chimeric gene (MTgIL-2). Nine (2 gIL-2 and 7 MTgIL-2 transgenics) out of 12 transgenic mice which were obtained independently had motor ataxic symptoms. All transgenic offspring of the symptomatic founders showed the same symptoms as their transgenic parents. Morphological examination demonstrated perivascular lymphocyte accumulation in the cerebellar meninx which was followed by increased cell infiltration of neutrophils and monocytes in the destructive cerebellum of all transgenic mice. These findings suggest that the lymphocyte infiltration in the cerebellum is caused by the specific effect of the exogenously introduced human IL-2 gene.

Animals↗
PubMed1989

Natural killer cells in inflammatory lesions and transplanted tumors in mouse skin.

The mode of natural killer (NK) cell migration to the sites of inflammation and transplanted tumors was investigated by using dry ice for physical irritation and 1-fluoro-2,4 dinitrobenzene (DNFB) for chemical irritation in mouse ear. In experiments with transplanted tumors, NK cell sensitive tumor cells (RL male 1) and insensitive tumor cells (p815) were transplanted into the ears of C3H and BALB/c mice, respectively. Employing a polyclonal rabbit antiserum against asialoGM1 (GA1), and a monoclonal rat antiserum against Thy-1 in an immunohistochemical double-staining technique, we enumerated the number of Thy-1-positive and asialoGM1-positive (Thy-1+ GA1+) cells and Thy-1-negative and asialoGM1-positive (Thy-1-GA1+) cells at various times of irritation. Following physical irritation, Thy-1-GA1+ cells (108.8 +/- 4.5/mm2 at 24 h and 71.2 +/- 3.8/mm2 at 48 h) were found in the epidermis, whereas Thy-1+GA1+ cells were not found. In delayed-type skin reaction by DNFB, Thy-1-GA1+ cells (87.1 +/- 5.8/mm2 at 24 h and 60.7 +/- 2.9/mm2 at 48 h) and Thy-1+GA1+ cells (26.4 +/- 3.6/mm2 at 24 h and 15.3 +/- 4.3/mm2 at 48 h) were found in the dermis. Since it was reported by previous investigators that Thy-1+GA1+ cells are NK cells, we assumed that NK cells infiltrated nonspecifically in the dermis in delayed-type skin reaction by DNFB. In the tumor transplant experiments, the GA1+ cells were found near both types of tumors, but they were in contact with RL male 1 and not with p815. Because it was reported that GA1+ monocytes do not have cytotoxicity against tumor cells, our findings suggest that GA1+ cells migrate nonspecifically to the sites of inflammation, and that the NK cells among them may make direct contact with the tumor cells when they encounter NK cell sensitive tumors.

Acute-Phase Reaction↗
PubMed1989

Cyclosporin A and anti-Ia antibody cause a maturation defect of CD4+8- cells in organ-cultured fetal thymus.

The effects of anti-Ia antibodies and cyclosporin A (CsA) on phenotypic differentiation of murine thymocytes were assessed in organ-cultured fetal thymuses. Both agents specifically abrogated the generation of CD4+8- thymocytes. Immunohistochemical studies revealed that Ia antigen on the organ-cultured thymic epithelial cells did not disappear with the addition of the agents, although anti-Ia antibody was proved to bind to Ia antigen during the culture. On the other hand, CsA neither changed the expression of Ia nor bound to it. As CsA is known to block the signalling cascade initiated by perturbation of T-cell receptor (TcR), it is suggested that both the Ia expression in the thymus and the signalling via receptors on thymocytes, the signals presumably generated by TcR binding to class II MHC molecules, might be necessary for phenotypic differentiation of class II MHC-restricted T cells (CD4+8- cells), but not for class I MHC-restricted T cells (CD4-8+).

Animals↗
PubMed1988

CD4+CD8+ thymocytes develop into CD4 or CD8 single-positive cells in athymic nude mice.

A differentiation pathway from CD4+CD8+ cells to CD4+CD8- or CD4-CD8+ cells was investigated in athymic nude mice. Using fluorescence-activated cell sorter, CD4+CD8+ cells were sorted out from AKR thymocytes (H-2k, Thy-1.1) stained with two monoclonal antibodies against CD4 and CD8 (anti-L3T4 and anti-Ly-2). These CD4+CD8+ AKR thymocytes were injected i.v. into CBA or C3H nude mice (H-2k, Thy-1.2) which had received 650 rads and had been reconstituted with syngeneic nude bone marrow cells. The lymph node cells of the nude recipients at 4 wks post-thymocyte transfer were shown to contain 50% AKR-derived Thy-1.1+ cells. The majority of the Thy-1.1+ cells were found to express either CD4 or CD8 alone but not to express both CD4 and CD8. These findings indicate that CD4+CD8+ thymocytes can develop into CD4+CD8- and CD4-CD8+ single-positive cells in extrathymic tissues.

Animals↗
PubMed1987

Immunoglobulin heavy chain gene diversification in the long-term bone marrow culture of normal mice and mice with severe combined immunodeficiency.

The change of immunoglobulin heavy (H) chain gene configuration during the differentiation of B cells from their early precursors was investigated in long-term cultures of bone marrow cells (LTBC). Hemopoietic stem cells are maintained in LTBC described by Dexter et al. (J. Cell. Physiol. 1977. 91: 335; LTBC-D), which supports the differentiation of myeloid lineage cells but not B lineage cells. By simply shifting the culture condition to that devised by Whitlock and Witte (Proc. Natl. Acad. Sci. USA 1982. 79: 3608; LTBC-B) to support the development of B lineage cells, surface IgM-bearing (sIgM+) B cells became detectable by the 2nd week after the shift and the number quickly increased thereafter, while the number of polymorphonuclear cells and granulocyte-macrophage colony-forming cell (CFU-c) decreased rapidly. H chain gene configuration of the developing cells in the culture was examined by Southern blot analysis of Eco RI-digested DNA with a JH probe. Whereas rearranged JH gene configuration was not detectable in the DNA from LTBC-D cells, it first appeared 2 weeks after the shift, and the level of the rearrangement rapidly increased thereafter as the intensity of JH band of germ-line configuration decreased. Almost all the cells in the culture had undergone H chain gene rearrangement in both chromosomes by the 6th week after the shift. During 2 to 4 weeks after the shift, a cluster of bands spanning around 4.5-5.5 kb appeared dominant among the rearranged configurations of JH gene and then it decreased in intensity as the pattern of JH band became a more homogeneous smear. The distribution of rearranged JH bands observed during 3-4 weeks after the shift was strikingly similar to that observed in normal spleen B cells. By semi-quantitative analysis of the intensity of JH and DSP2 bands remaining in germ-line configuration, it was found that the loss of germ-line JH band was far more rapid than that of germ-line DSP2 bands in the developing B cells in vitro. This result is consistent with the conclusion obtained in B cell tumor lines that D to J assembly occurred first and was followed by V to DJ assembly in this culture system. Taken together, it is likely that the process of H chain gene diversification in this culture system may represent the actual process during B cell differentiation in vivo. Differentiative capacity of bone marrow stem cells from mouse with severe combined immunodeficiency (SCID) was also analyzed in the same culture system.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Correlation of T cell receptor gene rearrangements to T cell surface antigen expression and to serum immunoglobulin level in scid mice.

The severe combined immunodeficient (scid) mouse which has undetectable serum immunoglobulin (Ig) contains a small number of thymic lymphocytes which express Thy-1 and IL2 receptors (IL2R) but not Lyt-2 or L3T4 molecules. These thymocytes did not show any rearrangement of T cell receptor (TCR) beta-chain genes. Such thymocyte characteristics in the scid mouse were similar to the 15-day embryonic thymocytes in ordinary mice, indicating that the scid mouse thymocytes are arrested in the early stage of intrathymic differentiation. However, low or medium level serum Ig was occasionally found in the littermates of the scid mouse. The thymocytes of these mice showed some evidence of TCR beta-chain gene rearrangement and the presence of Lyt-2+/L3T4+ cells in correlation with the serum Ig level. In the mice with some serum Ig the thymocyte cell number was increased and the proportion of IL2R+ cells was decreased. Collectively, these results suggest that the rearrangement of TCR beta-chain genes is associated with the expression of Lyt-2 and L3T4 molecules in intrathymic differentiation and probably with cell proliferation of the migrated lymphoid cells in the scid mouse.

Animals↗
PubMed1986

Two natural killer cell populations which belong to T cell lineage in nude mice.

Enriched natural killer (NK) cell populations from BALB/c nude mice obtained by using nylon wool column (NWC) separation were stained with anti-Thy-1 and anti-asialo GM1 (GA1), and then were fractioned by flow cytometry into 4 cell populations: Thy-1+GA1+ cells, Thy-1+GA1- cells, Thy-1-GA1+ cells and Thy-1-GA1- cells. These cell populations were sorted out by flow cytometry and were examined for NK activity. Of the sorted cells, high NK activity was found in the two populations, Thy-1+GA1+ cells and Thy-1-GA1+ cells. In the other populations expressing Thy-1 antigen alone or expressing neither GM1 nor Thy-1, NK activity was almost undetectable. The two cell populations with NK activity were lineaged with respect to rearrangement of the T cell receptor genes. Southern gel analysis using a cDNA probe containing the D beta 1, J beta 1.3 and C beta 1 genes of the T cell receptor showed a reduction of the germ-line band of DNA in the 3 fractionated populations other than Thy-1-GA1- cells. Since these observations were demonstrated in nude spleen cells, it is indicated that the cells with NK activity belong to T cell lineage even if they lack Thy-1 expression and that they may develop out of the thymus, if they express Thy-1 antigen.

Animals↗
PubMed1985

Expression of interleukin 2 receptor on murine fetal thymocytes.

Rat monoclonal antibodies AMT-13, 3C7 and 7D4 which react to the mouse interleukin 2 (IL 2) receptors were used to define cell populations with the putative IL 2 receptors in the mouse thymus as a part of series of investigations to elucidate the mechanism of intrathymic cell proliferation and differentiation. With freshly dissociated cells from the thymus of 15 gestational days, the anti-IL 2 receptor monoclonal antibodies (anti-IL 2 receptor) reacted with about half of them. The proportion of the reactive cells decreased rapidly thereafter till birth as the numbers of thymus cells expanded. The antibodies reacted with only two to three percent of thymic cells from newborn mice and less than one percent of cells from adult thymus. Through the gestational period, the fetal liver cells did not react with the antibodies. When the thymus cells at early gestational days were subjected to a two-color analysis, one for the anti-IL 2 receptor and the other for anti-Thy-1 or anti-asialo GM1, by a fluorescence-activated cell sorter, it was found that the majority (up to 80%) of anti-IL 2 receptor-reactive cells (IL 2 receptor-positive cells) was also reactive with anti-Thy-1. Some of the IL 2 receptor-positive cells but Thy-1-negative cells reacted with anti-asialo GM1, a marker of the immature thymocytes. Immunohistochemically, the IL 2 receptor-positive cells were found mainly in the subcapsular area and in the border region of cortex and medulla. Collectively, these results suggest that the pre-T lymphocytes are stimulated immediately after their arrival to the thymus from the stem cell source such as fetal liver and bone marrow and are driven into the proliferation via the IL 2 receptor system.

Animals↗
PubMed1985

The in vivo role of murine natural killer cells in the development of B cell lineage in bone marrow.

Physiological functions of natural killer (NK) cells in the development of bone marrow cells into the cells expressing B cell characteristics were examined in recipient mice expressing different allotype immunoglobulins (Ig) or in mutants defective in lipopolysaccharide (LPS) response. When the irradiated BALB/c nude mice (Igha) were injected with bone marrow cells of C57BL/6N (B6,Ighb), the level of donor-type serum Ig (Ighb) was about 10 fold higher in the mice with NK activity depleted by injecting anti-asialo GM1 compared to that of mice with the normal NK activity on day 21 after bone marrow transplantation. In the irradiated C3H/HeJ (low responder) which received bone marrow cells of C3H/HeN (high responder), augmentation of polyclonal antibody response and of the cell proliferation with LPS was demonstrated in the NK depleted mice. However, the difference in the level of donor-type Ig or LPS response between the NK-depleted and intact mice disappeared in 3 to 4 weeks. In normal mice without irradiation and marrow cell transplantation, NK cell elimination from spleen cells did not give rise to distinctly enhanced responses to in vitro LPS stimulation, whereas mice with augmented NK activity by poly I:C demonstrated a suppressed response to LPS when the mice were immunized with LPS. Collectively, these observations suggested that NK cells are involved in the suppressive regulation of developing B cell lineage as well as activated B cells in vivo.

Animals↗
PubMed1984

Feedback suppression of the immune response in vivo. III. Lyt-1+ B cells are suppressor-inducer cells.

We previously demonstrated that injection of a high dose (4 X 10(9] of sheep erythrocytes (SRBC) into C57BL/6 mice results in the generation of splenic B cells (plastic nonadherent, Thy-1- and Ig+) which, when transferred to normal syngeneic recipients, subsequently induce antigen-specific suppressor T cells to suppress the recipient's plaque-forming cell (PFC) responses to SRBC. In the present study we characterized the suppressor-inducer B cells phenotypically. Cytotoxic treatment of the donor's immune spleen cells with anti-Lyt-1 antibody plus complement (C'), but not with anti-Lyt-2 antibody plus C', relieved the suppression of PFC responses in recipients. The FcRr+ population separated by EA-rosette formation showed enriched suppressor-inducing activity, whereas the FcRr- population showed no activity. Our findings, taken together with the previous ones, suggest that suppressor-inducer cells are Thy-1-, Lyt-1+, Lyt-2-, FcRr+, and Ig+.

Animals↗
PubMed1984

Lysis of uninfected and virus-infected cells in vivo: a rejection mechanism in addition to that mediated by natural killer cells.

To examine the lysis of virus-infected cells in vivo, uninfected and lymphocytic choriomeningitis virus (LCMV)-infected L-929 cells were labeled in vitro with [125I]-iododeoxyuridine and implanted intravenously into mice. Natural cytotoxicity against both uninfected and virus-infected cells was demonstrated in normal uninfected mice, but LCMV-infected cells were cleared from the lungs and whole bodies more rapidly than uninfected cells. Treatment of L-929 cells with defective interfering LCMV inhibited standard virus synthesis and protected the target cells from enhanced in vivo rejection. The in vivo rejection was apparently mediated by a cellular constituent of the host immune response and not simply a result of virus-induced cytopathic effects on the target cell, as hydrocortisone acetate and cyclophosphamide each reduced rejection of both target cell types and eliminated the enhanced rejection of LCMV-infected cells. The enhanced rejection of LCMV-infected cells was not restricted by histocompatibility antigens, indicating that classic T-cell recognition was not involved in the lysis, and since the enhanced rejection of LCMV-infected cells was mediated by mice treated with cobra venom factor, complement was also not involved in the lysis. Although moderate levels of interferon (102 U/ml) were present in the sera and although there was a modest activation of natural killer (NK) cells in the lungs of LCMV-infected cell recipients but not uninfected cell recipients, the enhanced rejection of virus-infected cells did not appear to be NK cell mediated. Normal mice and mice depleted of NK cell activity by in vivo treatment with antibody to asialo ganglio-n-tetraosylceramide ( AGM1 ) rejected uninfected and LCMV-infected L-929 cells similarly. This antibody markedly inhibited the rejection of NK-sensitive YAC-1 cells. In addition to the natural cytotoxicity directed against virus-infected cells, a second nonspecific rejection mechanism appeared in response to treatment protocols which induced interferon. Polyinosinic-polycytidylic acid and infection with LCMV augmented in vivo rejection of both uninfected and LCMV-infected L-929 cells but eliminated the differential rejection of the virus-infected cells. Infection with LCMV also augmented the in vivo rejection of the NK-sensitive target cell, YAC-1. In vivo treatments with anti- AGM1 sera only moderately inhibited the elevated rejection of uninfected and LCMV-infected L-929 cells, indicating that the enhanced rejection of these target cells was predominantly mediated by a mechanism other than that mediated by NK cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

In vivo significance of NK cell on resistance against virus (HSV-1) infections in mice.

Susceptibility to infection with herpes simplex virus type 1 (HSV-1) was examined in euthymic as well as athymic nude mice which were continuously depleted of natural killer (NK) cell activity by i.v. injection of anti-asialo GM1. In those NK cell activity-depleted mice, the mortality rate of infection with HSV-1 and the virus titers in the brain, liver, and spleen were notably higher than in the control mice. The enhanced susceptibility was demonstrated only in the mice receiving anti-asialo GM1 and HSV-1 simultaneously, but not in the mice in which NK cell deletion was postponed by injecting the antisera 5 days after the virus inoculation. Interferon (IFN) production of peritoneal exudate cells was also reduced in the anti-asialo GM1-injected mice. The decline of resistance against HSV-1 infection proved to be primarily due to deletion of NK cells, but not due to the inability to produce IFN, because repeated injections of IFN increased the NK cell activity and prolonged the life of HSV-1-infected mice with an intact NK cell activity. In the NK cell activity-depleted mice, however, neither the NK cell activity nor the life span was improved by the administration of IFN.

Animals↗
PubMed1983

Purine nucleoside metabolizing enzyme activities in mouse thymocytes at different stages of differentiation and maturation.

The activities of the enzymes involved in purine nucleoside metabolism, adenosine deaminase (ADA), adenosine kinase (AK), purine nucleoside phosphorylase (PNP) and deoxycytidine kinase (deoxyCRK), were determined in mouse thymocytes at various stages of differentiation and maturation, and compared with those in other tissues. The thymocytes were characterized by high ADA and deoxyCRK activities with high ADA/AK and ADA/PNP ratios and low PNP/deoxyCRK ratio. In fetal thymocytes of 16 gestational days, ADA activity was lower, and PNP, AK and deoxyCRK activities were higher than those in the adult thymocytes. During differentiation of fetal thymocytes, ADA activity increased while PNP and AK activities decreased. DeoxyCRK activity decreased after birth. In spleen T lymphocytes, ADA and deoxyCRK activities were lower and PNP activity was about 2.5-fold higher than in the thymocytes. Thus the differentiation stages of T lymphocytes may be characterized by the absolute levels and the ratios of these enzymes.

Adenosine Deaminase↗