Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We searched for the presence of suppressor cells of the MLR in C57BL/Ka leads to BALB/c chimeras. The chimeras were made with total lymphoid irradiation (TLI) and marrow transplantation. Spleen cells from the old chimeras inhibited the MLR of BALB/c responder cells against C57BL/Ka stimulator cells. Inhibition was specific for the stimulator cells, since no effect on the MLR was observed with C3H or BALB.C3H stimulator cells. Maximal inhibition was achieved when the responder cells in the MLR shared the H-2 haplotype of the chimeric recipient. Spleen cells obtained from chimeras young 30 to 40 days after BM transplantation inhibited the MLR nonspecifically, since similar marked inhibition was observed regardless of the H-2 haplotype of the responder or stimulator cells. The finding of antigen-specific and nonspecific suppressor cells is similar to that observed in mice rendered tolerant to bovine serum albumin after treatment with TLI.
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PMID:Induction of allograft tolerance after total lymphoid irradiation (TLI): development of suppressor cells of the mixed leukocyte reaction (MLR). 15 66

Spleen cells from C3H/HeJ mice respond very poorly to the mitogenic action of endotoxin (LPS) in vitro whereas cells from a very closely related strain, C3H/HeN respond very well. An analysis of the genetic similarity of these two strains was performed. There is no significant MLR measurable between cells of these strains under a variety of culture conditions. They do not manifest a significant graft-vs-host response nor do they reject reciprocal skin grafts. Because of this genetic similarity, it is possible to reconstitute the LPS response of nonresponder mice by an adoptive transfer of spleen cells from C3H/HeN mice. This strain pair should therefore prove useful in analyzing the genetic and cellular basis of endotoxin reactivity.
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PMID:Difference in B cell mitogen responsiveness between closely related strains of mice. 23 63

It has been reported previously that spleen cells from (SJL x PL) F1 hybrid mice are not tolerant to SJL parental cells as assessed by a one-way MLR. The possibility that the F1 anti-SJL reaction was due to the effect of lymphokines produced by the irradiated SJL T cells in response to I-Eu expressed on the F1 hybrid cells was eliminated since inclusion of anti-I-E mAb was without effect. Cell separations showed the responder cells to be plastic and nylon wool nonadherent Ia- T cells. Separation of the SJL spleen cells showed that the stimulator cells were nonadherent, passed through a nylon wool column, and were Ia-. the F1-anti-SJL MLR was blocked 70 to 90% by inclusion of mAb KJ23a in the culture medium that indicated that the stimulatory cell population was V beta 17a+ T cells. This was confirmed by the use of V beta 17a+ and V beta 17a-T cell clones as stimulators. To determine whether failure to develop tolerance to this T cell subset in F1 hybrid mice might be responsible for the F1-anti-parent MLR, (SJL x PL)F1 mice were treated at birth and 48 h thereafter with anti-I-E mAb for 7 wk. Spleen cells from antibody-treated F1 mice were nonreactive with irradiated SJL parental cells in contrast to spleen cells from control mice which indicated that V beta 17a+ T cells were eliminated by negative selection before the development of tolerance.
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PMID:Failure of (SJL/J x PL/J)F1 hybrid mice to develop immunologic tolerance to V beta 17a+ T cells results in F1 anti-SJL mixed lymphocyte reaction. 168 74

Cervical lymph node (CLN) cells and spleen cells were harvested from virgin and pregnant rats bearing syngeneic or allogeneic fetuses at all stages of pregnancy including the pre-implantation period. The specific and non-specific alloreactivity of these cells were analyzed in MLR against mitomycin-C treated paternal strain or unrelated cells. Mitogen stimulation of the cell cultures utilized PHA, Con-A and PWM. Cells bearing T cell markers were labeled in an indirect assay using the monoclonal antibodies W3/25 and MRC OX 8. Specific alloreactivity is enhanced at mid-pregnancy in both cell populations. Non-specific alloreactivity was suppressed in the cervical lymph node cells. Spleen cells demonstrated an increased non-specific alloreactivity and T polyclonal mitogen reactivity (PHA and Con-A) at mid-pregnancy. Reactivity to Con-A was depressed in the early phase and at the end of allogeneic pregnancy in the CLN. The CD4+/CD8+ ratio was very low during all phases of pregnancy.
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PMID:Reactivity to alloantigens and polyclonal mitogens and CD4+/CD8+ cell ratio shifts of cervical lymph node and spleen cells during pregnancy in rats. 183 1

In models of tolerance associated with mixed lymphoid chimerism, depletion of Thy 1+ cells from the allogeneic donor inoculum may decrease the level of chimerism achieved and the capacity of donor cells to induce tolerance. To determine whether the apparent role of Thy 1+ cells in the facilitation of bone marrow engraftment and induction of skin graft tolerance is related to alloaggression, the capacity of fully allogeneic C57BL/6J, H-2b BM cells to establish mixed lymphoid chimerism and skin graft tolerance in sublethally irradiated (2.5 Gy x 3) BALB/c, H-2d hosts was compared with that of semi-allogeneic BALB/c x C57BL/6J F1 H-2d/b BM cells which genetically lack the potential for graft-versus-host reactivity against parental recipients. The levels of mixed chimerism observed with allogeneic and semi-allogeneic F1 BM cells were nearly identical: 21.0 +/- 9.7% of spleen cells in H-2b BM-injected and 18.6 +/- 8.8% of spleen cells in H-2d/b BM-injected H-2d hosts were of donor allotype. There was no difference in the fraction of hosts rendered tolerant to C57BL/6J, H-2b skin grafts by H-2b vs. H-2d/b BM at either excess (94% vs. 92% tolerant) or threshold (37% vs. 40% tolerant) numbers of donor cells. Spleen cells from both types of mixed chimeras failed to respond to donor antigens in MLR. Both H-2b and H-2d/b BM-injected H-2d hosts rejected third party C3H/HeJ, H-2k skin grafts and responded to third party stimulators in MLR. Although these nonspecific allo-immune responses were not as strong as the responses of normal animals, they were suppressed to an equivalent degree in both types of chimeras. Graft-versus-host disease, if present in irradiated H-2b BM-injected hosts, did not significantly affect survival compared with survival of irradiated H-2d/b BM-injected animals. These results suggest that the tolerizing capacity of allogeneic BM does not depend upon GVHD and that allogeneic and semi-allogeneic BM establish mixed lymphoid chimerism and induce skin graft tolerance by similar mechanisms across a complete MHC disparity in sublethally irradiated adult hosts.
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PMID:Allogeneic versus semiallogeneic F1 bone marrow transplantation into sublethally irradiated MHC-disparate hosts. Effects on mixed lymphoid chimerism, skin graft tolerance, host survival, and alloreactivity. 213 69

The immune response to allogeneic histocompatibility Ag can be suppressed by injecting allogeneic spleen cells into mice that have been previously exposed to UV radiation. The suppression is associated with Ag-specific suppressor T cells found in the spleens of the UV-irradiated mice. An intriguing and as yet unanswered question is how the irradiation of the animal's dorsal skin leads to the induction of splenic Ag-specific suppressor cells. Our data suggest that soluble factors released by UV-irradiated keratinocytes are involved in the induction of Ag-specific suppressor cells. Injecting culture supernatants from UV-irradiated keratinocytes into normal mice produced the same effect as whole-body UV irradiation and suppressed the induction of delayed hypersensitivity to alloantigen. Spleen cells from these mice were unable to respond to the alloantigen in the MLR. Radiation-resistant, suppressor T cells (CD3+, CD4+, CD8-) were found in the spleens of the mice injected with suppressive supernatants. Treating the keratinocytes with cycloheximide or treating the supernatants from the UV-irradiated keratinocytes with trypsin removed all suppressive activity, suggesting the active material is a protein. The suppressive activity bound to agarose beads coupled with Con A, and was eluted with alpha-methyl-D-mannoside, further suggesting the suppressive material is a glycoprotein. Because the suppression of the immune response to alloantigen induced by this suppressive cytokine mimicked the suppression found after exposure to UV radiation, these findings support the concept that the induction of systemic suppression by UV-irradiation results from the release of suppressive substances by UV-irradiated keratinocytes. In addition, these data suggest that the induction of Ag-specific suppressor cells by this factor may provide a novel method of suppressing allograft rejection.
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PMID:Suppression of the immune response to alloantigen by factors released from ultraviolet-irradiated keratinocytes. 214 79

Spleen cells from mice receiving TLI, with or without thymus shielding, were investigated for in vitro and in vivo defects. At 4-6 weeks after irradiation spleen cells of both groups showed a normal number of Thy1 (T cells), L3T4 (CD4 positive T cells) cells, and an absence of natural suppressor cells. Splenocytes of the nonthymic shielded TLI group were not able to mount either a normal in vitro response (in MLR or PHA) or an in vivo graft-versus-host-disease reaction when injected into lethally irradiated adult allogeneic recipients or into neonatal F1 hybrids. This was in contrast to the normal immune capacity of spleen cells from the thymus shielded group that gave normal MLR and PHA tests in vitro and provoked GVHD in vivo. Thymuses recovered from mice receiving TLI with or without thymic shielding were however equally efficient in restoring the immune capacity after transplantation into neonatally thymectomized mice as measured by the PHA assay. Thymic irradiation is therefore necessary but not sufficient for creating long-lasting immune defects after TLI.
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PMID:Effects of thymus irradiation on the immune competence of T cells after total-lymphoid irradiation. 236 57

The effects of administration of donor lymphocytes via portal vein (PV) on capacity of alloreactivity and renal allograft survival were investigated in comparison with those of intra-venous (IV) administration in the rats. Orthotopic renal transplantations were performed from Brown-Norway (BN, RT-In) to Lewis (LEW, RT-11) male rats. Donor lymphocytes were prepared from BN or third party DA(RT-1a) rat spleens and lymph nodes and injected via PV or IV to LEW rats on the day of transplantation (day 0). Untreated LEW hosts rejected BN grafts at 7.8 +/- 0.6 days (n = 10). IV administration of 1 x 10(8) BN cells to LEW rats caused a slight prolongation of BN graft survival to 10.4 +/- 3.1 days (n = 9, p less than 0.05), whereas PV inoculation of the same number of BN cells further prolonged graft survival to 28.9 +/- 9.2 days (n = 9, p less than 0.01). This effect was antigen specific; the administration of 1 x 10(8) third party DA cells via PV to LEW rats did not prolong survival of BN graft (MST = 7.4 +/- 0.8, n = 6). Serum from tolerant recipients had significant antigen specific suppressor effect (70.6%) on the MLR proliferative reaction of LEW responder cells toward donor BN cells, but not third party DA cells. Spleen cells from these recipients did not show any suppressive effect. These results demonstrate that PV administration of donor lymphoid cells to recipients results in rapidly inducible and long-lasting immunologic tolerance specific to donor alloantigen, and that this tolerance is mediated by serum factor induced in hosts, but not by suppressor cells.
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PMID:[Effects of portal venous administration with allogenic cells on renal allograft survival in the rat]. 248 May 16

The capacity of dendritic cells to present protein antigens has been studied with two MHC class II-restricted, myoglobin-specific, T cell clones. Spleen dendritic cells and cultured epidermal Langerhans cells (LC) presented native myoglobin weakly and often not at all. These same populations were powerful stimulators of allogeneic T cells in the primary MLR. Freshly isolated LC were in contrast very active in presenting proteins to T cell clones but were weak stimulators of the MLR. Both fresh and cultured LC could present specific peptide fragments of myoglobin to the clones. These results suggest that dendritic cells in nonlymphoid tissues like skin can act as sentinels for presenting antigens in situ, their accessory function developing in two phases. First antigens are captured and appropriately presented. Further handling of antigen then is downregulated while the cells acquire strong sensitizing activity for the growth and function of resting T lymphocytes. The potent MLR stimulating activity of cultured epidermal LC and lymphoid dendritic cells probably reflects prior handling of antigens leading to the formation of allogeneic MHC-peptide complexes.
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PMID:Presentation of exogenous protein antigens by dendritic cells to T cell clones. Intact protein is presented best by immature, epidermal Langerhans cells. 252 97

Prior work has shown that purified, resident, and inflammatory peritoneal macrophages are weak stimulators of the allogeneic MLR. We have identified conditions whereby thioglycollate-elicited macrophages become stimulatory, but primarily for the CD8+ T cell subset. The conditions were to treat the macrophages with neuraminidase and to supplement the MLR with rIL-2. These treatments together led to proliferative and cytotoxic responses by isolated CD8+ but not CD4+ T cells. Likewise when MHC-congenic strains were evaluated, an MLR was observed across isolated class I but not class II MHC barriers. Pretreatment of the macrophages with IFN-gamma further enhanced expression of class I MHC products and stimulatory activity, but did not seem essential. While these treatments did not render macrophages stimulatory for an MLR in purified CD4+ cells, blastogenesis of CD4+ cells was observed when the MLR involved bulk T cells. Small allogeneic B lymphocytes behaved similarly to macrophages, in the pretreatment with neuraminidase and supplementation with rIL-2 rendered B cells stimulatory for allogeneic, enriched, CD8+, but not CD4+, T cells. Spleen adherent cells, which are mixtures of macrophages and dendritic cells, stimulated both CD4+ and CD8+ T cells, and neither neuraminidase nor exogenous IL-2 was required. We think that these data suggest that most macrophages and small B cells lack three important functions of dendritic cells: a T cell-binding function that can be remedied by neuraminidase treatment, a T cell growth factor-inducing function that can be bypassed with exogenous IL-2, and an IL-2 responsiveness function that is required by CD4+ lymphocytes.
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PMID:Neuraminidase-treated macrophages stimulate allogenic CD8+ T cells in the presence of exogenous interleukin 2. 326 11


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