251
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Abstract
T cell anergy is a functionally defined state of hyporesponsiveness in which T cells neither proliferate nor produce IL2 following subsequent TCR ligation. Recent biochemical data from in vitro studies suggest that anergic cells do not utilize all of the signaling pathways normally initiated by TCR triggering. These findings appear to hold true for T cells rendered anergic in vivo, as well; however, biochemical studies on clonal anergy in vivo have been limited by the inability to recover a homogeneous population of anergic T cells. Here we review progress on TCR mediated signaling pathways as well as the description of surface marker phenotypes specific to T cell anergy.
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Affiliation(s)
- C C Maier
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
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252
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Abstract
Superantigens are bacterial or viral products that polyclonally activate T cells bearing certain TCR beta chain variable elements. For instance, Vbeta8+ T cells proliferate in response to staphylococcal enterotoxin B (SEB) in vivo and then undergo Fas- and/or TNF-mediated apoptosis. We have recently shown that apoptotic SEB-reactive T cells express the B cell marker B220. Here we report the identification of a novel subset of CD4+ B220+ T cell blasts that are the precursors of these apoptotic cells in SEB-immunized mice. Moreover, we show that the CD4- CD8- B220+ T cells that accumulate in the lymphoid organs of Fas ligand-defective gld mice stably express a form of the B220 molecule which exhibits biochemical similarities to that expressed by activated wild-type T cells, but is distinct from that displayed on the surface of B cells. Surprisingly, we also find a population of CD4+ B220+ pre-apoptotic T cells in FasL-defective gld mice, arguing that these cells can be generated in a Fas-independent fashion. Collectively, our data support a general model whereby upon activation, T cells up-regulate B220 before undergoing apoptosis. When the apoptotic mechanisms are defective, T cells presumably down-regulate their coreceptor molecules but retain expression of B220 as they accumulate in lymphoid organs.
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Affiliation(s)
- T Renno
- Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland
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253
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Mason KM, Bigley NJ, Fink PS. Development of a novel in vitro co-culture system for studying host response to native bacterial antigens. J Immunol Methods 1998; 211:147-58. [PMID: 9617839 DOI: 10.1016/s0022-1759(97)00200-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have developed a novel co-culture system in which murine splenocytes are cultured with live bacteria in the presence of a bacteriostatic antibiotic. Superantigens, like staphylococcal enterotoxin B (SEB) are important factors in bacterial pathogenicity. Research has shown that superantigens affect numerous immune cell types, either directly or indirectly, yet their involvement in pathogenic mechanisms remains poorly defined. In these studies, we utilize the co-culture system to study how superantigen pretreatment affects interferon-gamma (IFN-gamma) production by splenocytes co-cultured with gram-positive bacteria. Streptococcus mutans, S. sanguis and Bacillus subtilis were tested for susceptibility to a panel of antibiotics. Spectinomycin was found to maintain a bacteriostatic state of approximately 10(5) bacteria ml(-1) at optimal concentrations for each bacterial strain. Co-culturing splenocytes with bacteria did not affect splenocyte viability and cultured splenocytes responded to mitogenic stimulation as expected. Two days after SEB pretreatment, isolated splenocytes cultured with either Streptococcus species produced 10-15 times more IFN-gamma than splenocytes from sham-injected controls; however, no differences in CD4+ or CD8+ T cell populations appeared in cultures with or without bacteria. Splenocytes isolated four days after SEB treatment did not produce significant amounts of IFN-gamma in co-culture. Co-cultures containing live bacteria produced four times more IFN-gamma than cultures containing heat-killed bacteria. Splenocytes depleted of natural killer (NK) cells prior to SEB treatment produced 25% less IFN-gamma after 20 h co-culturing with S. mutans. T lymphocytes were identified to be the major producer of IFN-gamma at this time point by intracellular cytokine staining. Apparently SEB exposure primes a response to live bacteria and the response is evident two days after initial exposure. The in vitro co-culture system allows us to observe host responses to bacteria in the context of the multicellular interdependent immune response. With this assay we can more closely 'mimic' in vivo events, particularly immune cell interactions in microfloral environments, to study how the pathogenic effects of superantigens alter this response.
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Affiliation(s)
- K M Mason
- Department of Microbiology and Immunology, Wright State University, Dayton, OH 45435, USA
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254
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Noble A, Pestano GA, Cantor H. Suppression of Immune Responses by CD8 Cells. I. Superantigen-Activated CD8 Cells Induce Unidirectional Fas-Mediated Apoptosis of Antigen-Activated CD4 Cells. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.2.559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Stimulation of mature CD4 cells through the TCR induces cellular activation and expansion that are often followed by clonal elimination by a form of apoptosis3 termed activation-induced cell death. This process of CD4 cell apoptosis is generally thought to reflect clonal suicide and to be independent of other cell types. Here we show that during the response to the superantigen Staphylococcal enterotoxin A, activated CD8 cells, but not activated CD4 cells, suppress the CD4 proliferative response. Suppression by CD8 cells reflects their ability to induce CD4 cell apoptosis via ligation of Fas. Moreover, although activated CD8 cells that express Fas ligand and Fas eliminate CD4 cells through a Fas-dependent mechanism, they are themselves resistant to Fas-dependent apoptosis. These findings indicate a fundamental difference between the two major T cell subsets with regard to sensitivity to Fas-dependent apoptosis, expression of Fas ligand, and mediation of suppressive activity following immunization with superantigen.
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Affiliation(s)
- Alistair Noble
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Gary A. Pestano
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Harvey Cantor
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, MA 02115
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255
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Zheng L, Trageser CL, Willerford DM, Lenardo MJ. T Cell Growth Cytokines Cause the Superinduction of Molecules Mediating Antigen-Induced T Lymphocyte Death. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.2.763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
TCR stimulation of T lymphocytes that are activated and cycling in the presence of IL-2 leads to programmed cell death. We now show that this effect is at least partly attributable to the ability of IL-2 to dramatically increase the expression of mRNAs encoding ligands and receptors that mediate apoptosis. We also found that cyclosporin was not able to fully inhibit the TCR induction of death molecule mRNAs or TCR-induced apoptosis, although it could completely turn off IL-2 expression. The effect of growth cytokines was further explored in T cells derived from mice bearing a homozygous deficiency of the IL-2R α-chain. We found that IL-2Rα−/− cells were resistant to death if IL-2 was used to induce apoptosis susceptibility, but that large amounts of other T cell growth cytokines, such as IL-4 and IL-7, could induce cell cycle progression and promote TCR-induced apoptosis. However, our findings suggest that autoimmunity and lymphoproliferation in IL-2Rα−/− mice can result from the loss of IL-2-stimulated feedback apoptosis and that other growth cytokines are not produced at levels sufficient to compensate for this deficit.
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Affiliation(s)
- Lixin Zheng
- *Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
| | - Carol L. Trageser
- *Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
| | - Dennis M. Willerford
- †Department of Medicine, University of Washington and Puget Sound Blood Center, Seattle, WA 98104
| | - Michael J. Lenardo
- *Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
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256
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Goldman-Brezinski S, Brezinski K, Zhang XM, Gienapp I, Cox K, Heber-Katz E, Whitacre C. Effects of oral tolerance induction by myelin basic protein on Vbeta8+ Lewis rat T cells. J Neurosci Res 1998; 51:67-75. [PMID: 9452310 DOI: 10.1002/(sici)1097-4547(19980101)51:1<67::aid-jnr7>3.0.co;2-j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Encephalitogenic T cells from Lewis rats use a restricted T cell receptor (TCR) gene combination, Vbeta8.2 and Valpha2. The oral administration of myelin basic protein (MBP) to Lewis rats prior to encephalitogenic challenge results in a marked inhibition of clinical neurologic signs of encephalitis, reduced central nervous system pathology, suppressed T cell reactivity to MBP, and decreased serum anti-MBP antibody responses. The present study determined the TCR Vbeta8 gene usage in rats rendered orally tolerant to MBP as compared with vehicle-fed or unfed controls. Total RNA was extracted from lymph node cells (LNC), Northern blots run, and hybridizations performed using a rat beta chain V region probe positive for Vbeta8.2. The results indicate that feeding MBP results in a decrease in Vbeta8+ TCR RNA expression in lymph nodes draining the site of encephalitogenic challenge. T cell proliferation was reduced in LNC of tolerized rats relative to control rats. No change in the Vbeta8+ TCR RNA expression or MBP reactivity was observed in the mesenteric lymph nodes (MLN) of vehicle-fed or MBP-fed rats, although an increase in cell number was found in the MLN of both groups. These results suggest that the mechanisms of orally induced tolerance involve local clonal deletion or migration of Vbeta8+ T cells, of which MBP-specific T cells are a part.
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257
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Abdul-Majid KB, Abedi-Valurgerdi M. T cell dependent B cell activation occurs during the induction of T cell anergy by staphylococcal enterotoxin B in mice. Immunol Invest 1998; 27:73-88. [PMID: 9561919 DOI: 10.3109/08820139809070891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Staphylococcal enterotoxin B (SEB) can activate specific T cell clones bearing specific TcR V beta domains together with MHC class II ligands on accessory cells. The release of proinflammatory cytokines is the consequence of this activation as well as the main pathological aspect involved in SEB infection. This current study looked at the active role of both T and B cells during the induction of anergy by SEB in vivo. Euthymic and nude BALB/c mice were injected with SEB and over a period of 8 days, cells from the spleen and sera from the blood were collected. After a single injection with SEB (50 micrograms/mouse), a transient increase of CD4+V beta 8+ T cells were detected after 2 days followed by a decrease after 4 days, which persisted until day 8. These clones were rendered anergic upon restimulation in vitro with SEB. Interestingly, cells taken out 2 days after SEB injection, exhibited reduced proliferation in response to Con A. However, this response gradually recovered on days 4, 6 and 8. Furthermore, early IgM antibody production (day 2) was observed after SEB injection. SEB-induced IgM antibody production in euthymic BALB/c was found to have specificity against SEB, cardiolipin (CL) and phosphatidylethanolamine (PE). SEB-treated nude mice did not produce antibody secreting cells in response to SEB, indicating that this process is T cell dependent.
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Affiliation(s)
- K B Abdul-Majid
- Department of Immunology, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
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258
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Bayles KW, Wesson CA, Liou LE, Fox LK, Bohach GA, Trumble WR. Intracellular Staphylococcus aureus escapes the endosome and induces apoptosis in epithelial cells. Infect Immun 1998; 66:336-42. [PMID: 9423876 PMCID: PMC107895 DOI: 10.1128/iai.66.1.336-342.1998] [Citation(s) in RCA: 286] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We examined the invasion of an established bovine mammary epithelial cell line (MAC-T) by a Staphylococcus aureus mastitis isolate to study the potential role of intracellular survival in the persistence of staphylococcal infections. S. aureus cells displayed dose-dependent invasion of MAC-T cells and intracellular survival. An electron microscopic examination of infected cells indicated that the bacteria induced internalization via a mechanism involving membrane pseudopod formation and then escaped into the cytoplasm following lysis of the endosomal membrane. Two hours after the internalization of S. aureus, MAC-T cells exhibited detachment from the matrix, rounding, a mottled cell membrane, and vacuolization of the cytoplasm, all of which are indicative of cells undergoing programmed cell death (apoptosis). By 18 h, the majority of the MAC-T cell population exhibited an apoptotic morphology. Other evidence for apoptosis was the generation of MAC-T cell DNA fragments differing in size by increments of approximately 180 bp and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of the fragmented nuclear DNA of the infected host cells. These results demonstrate that after internalization S. aureus escapes the endosome and induces apoptosis in nonprofessional phagocytes.
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Affiliation(s)
- K W Bayles
- Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow 83844, USA
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259
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Wang R, Ciardelli TL, Russell JH. Partial signaling by cytokines: cytokine regulation of cell cycle and Fas-dependent, activation-induced death in CD4+ subsets. Cell Immunol 1997; 182:152-60. [PMID: 9514696 DOI: 10.1006/cimm.1997.1220] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fas-dependent, activation-induced death (AID) of T cells has been implicated in the regulation of peripheral T cell populations. We have previously reported that IL-2 plays a unique role in regulating sensitivity to AID in primary CD4+ cells. In this report we have compared the capacity of IL-2, IL-4, and IL-7 to increase entry into cell cycle vs their capacity to increase sensitivity to AID. Our data indicate that IL-2 plays a unique role in the regulation of AID in both Th1 and Th2 subsets and that with a given AID stimulus, cell cycle progression is necessary, but not sufficient, for AID. Interestingly, induction of cell cycle entry and sensitivity to AID can be dissociated (partial signaling) not only with different cytokines, but even with point mutations in IL-2 itself. This provides the first evidence that cytokine variants or pharmacological agents that mimic their action will be useful in enhancing selective elements of pleiotropic cytokine actions.
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Affiliation(s)
- R Wang
- Department of Molecular Biology and Pharmacology, Washington University Medical School, St. Louis, Missouri 63110, USA
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260
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Kubo S, Hasegawa A, Hashimoto K, Shimizu C, Kubo M, Tada T, Nakayama T. CD4 regulates the efficiency of an endogenous superantigen-induced clonal deletion of TCRV beta 11+ cells in the periphery. Immunol Suppl 1997; 92:437-46. [PMID: 9497484 PMCID: PMC1364148 DOI: 10.1046/j.1365-2567.1997.00382.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Peripheral T-cell antigen receptor V beta (TCRV beta) repertoire is influenced by clonal deletion both in the thymus and periphery. Developing thymocytes expressing certain TCRV beta are deleted by endogenous superantigens presented on major histocompatibility complex (MHC) molecules in the thymus. Likewise, mature T cells bearing particular TCRV beta chains can be clonally deleted by superantigens in the periphery. The efficiency with which T cells expressing particular V beta subunits are deleted differs depending upon which coreceptor is expressed. Indeed, while deletion of V beta 11+ splenic T cells in CBA/J (Mls-1, a I-E, + MTV 9+) mice is quite efficient for CD4+ spleen T cells, it is much less efficient for CD8+ splenic T cells. If the difference in the efficiency of deletion is due solely to the coreceptor expressed, then a transgene encoding CD4 should increase the efficiency with which CD8+ cells are deleted. To address this question, we have produced CD4 transgenic (TG) mice that express physiologic levels of CD4 on all thymocytes and peripheral CD8 T cells. CD4 molecules expressed on CD8+ splenic T cells were associated with P56lck tyrosine kinase, and were functional as evidenced by their ability to facilitate class II alloreactivity. Furthermore, we found that ectopic expression of TG CD4 molecules on CD8+ cells was able to affect the efficiency of deletion in response to superantigen stimulation. In particular, deletion of TCRV beta 11+ T cells was much less efficient for CD8+ than for CD4+ T-cell subpopulations in (CBA/J x B6) F1 mice. However, expression of the CD4 transgene on CD8+ splenic T cells from these mice increased the efficiency of deletion in the CD8+ V beta 11 T cells. Interestingly, this effect was not observed in a mature CD8+ thymocyte subpopulation. The results in this report demonstrate that CD4 molecules are involved in peripheral deletion of TCRV beta 11+ T cells in (CBA/J x B6) F1 mice, and that the TCRV beta repertoire can be altered by ectopic expression of CD4 on all T-lineage cells.
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Affiliation(s)
- S Kubo
- Division of Immunobiology, Science University of Tokyo, Japan
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261
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Tomokuni A, Aikoh T, Matsuki T, Isozaki Y, Otsuki T, Kita S, Ueki H, Kusaka M, Kishimoto T, Ueki A. Elevated soluble Fas/APO-1 (CD95) levels in silicosis patients without clinical symptoms of autoimmune diseases or malignant tumours. Clin Exp Immunol 1997; 110:303-9. [PMID: 9367417 PMCID: PMC2265505 DOI: 10.1111/j.1365-2249.1997.tb08332.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Soluble Fas (sFas) is produced as translation products of alternative mRNA splicing, and antagonizes the membranous Fas molecule in Fas/Fas ligand interactions. We investigated the serum sFas levels in 64 Japanese silicosis patients with no clinical symptoms of autoimmune diseases or malignant tumours, using ELISA for sFas. The serum sFas levels in the silicosis patients were significantly higher than those in healthy volunteers. Elevated serum sFas levels were also detected in patients with systemic lupus erythematosus but, unexpectedly, no difference was observed in sFas levels between progressive systemic sclerosis patients and healthy volunteers. On the other hand, there was no significant difference in the expression of Fas on peripheral blood lymphocytes between the patients with silicosis and age-matched healthy volunteers. These observations provided the first evidence that serum sFas levels are elevated in silicosis patients without clinical symptoms of autoimmune diseases or malignant tumours. It remains to be clarified whether patients with elevated sFas levels have a tendency to develop autoimmune diseases later, or whether some other distinct factor(s) is necessary to initiate the progression of autoimmune diseases.
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Affiliation(s)
- A Tomokuni
- Department of Hygiene, Kawasaki Medical School, Kurashiki, Japan
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262
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Chedid MG, Deulofeut H, Yunis DE, Lara-Marquez ML, Salazar M, Deulofeut R, Awdeh Z, Alper CA, Yunis EJ. Defect in Th1-like cells of nonresponders to hepatitis B vaccine. Hum Immunol 1997; 58:42-51. [PMID: 9438208 DOI: 10.1016/s0198-8859(97)00209-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Peripheral blood lymphocytes from nonresponders to hepatitis B vaccine (HBsAg) failed to undergo a proliferative response to recombinant HBsAg in vitro, whereas cells from responders proliferated vigorously. The lack of proliferative response was not due to defective antigen presentation in that MHC-identical responder and nonresponder antigen presenting cells were equally effective in stimulating responder T cells. Nonresponder T cells did not proliferate in response to antigen-pulsed MHC identical responder antigen presenting cells. The present study demonstrated that: 1) there were no detectable (1 in < 20 x 10(4) HBsAg-precursor T cells in any of the nonresponders, while in responders the frequency of HBsAg-precursor T cells ranged from 1 in 3.2 x 10(3) to 1 in 40 x 10(3); 2) nonresponder cell cultures did not secrete IL-2 in response to HBsAg stimulation; 3) exogenous recombinant IL-2 did not restore the proliferative response of the T cells in HBsAg-pulsed cultures of nonresponders. These results suggest that the cellular basis for the lack of response to HBsAg is a defect in HBsAg-specific Th1-like cells; either there is an absence of the Th1 cells or cells with TCR specificity for HBsAg are present but are unresponsive to the HBsAg peptide-MHC complex (i.e., anergy or tolerance).
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Affiliation(s)
- M G Chedid
- Division of Immunogenetics, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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263
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Galdiero F, Galdiero M, Nuzzo I, Vitiello M, Bentivoglio C, Romano-Carratelli C. Polyclonal T cell elimination by prolonged immunostimulation in an experimental model. Clin Exp Immunol 1997; 110:182-8. [PMID: 9367400 PMCID: PMC2265497 DOI: 10.1111/j.1365-2249.1997.tb08315.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
An experimental model of immunological deficiency obtained by treating mice for 6 months with serum of human blood drawn from different healthy individuals has been studied. The results show that an alteration of a circulating lymphocyte population with alterations of the ratio CD4+/CD8+ appeared in mice stimulated for a long period with immunogens. Mice treated for 2-4 months showed an increase in B lymphocytes and a decrease in the total number of T lymphocytes, with a decrease in CD4+ lymphocytes and an increase in CD8+ lymphocytes. After 4 months, the CD8+ lymphocyte population started to decrease, with a ratio of CD4+/CD8+ reaching almost 1. In animals treated for 2-3 months, the mean survival time (MST) following experimental infection with Salmonella typhimurium presented a decrease to 5 days, and after 5-6 months of treatment presented a decrease to 3-2.5 days. The bacteraemia was modified in comparison with controls. Prolonged exposure to antigens also induced lymphocyte apoptosis: cells of animals treated for 4-6 months presented increased levels of apoptosis with a percentage that reached 30-35%. A semiquantitative evaluation of the level of heat shock protein (hsp) in splenic lymphocytes showed an increase in the presence of hsp60 and hsp70 in the first 3 months of treatment, which then remained constant for up to 6 months.
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Affiliation(s)
- F Galdiero
- Instituto di Microbiologia, Facoltà di Medicina e Chirurgia, Seconda Università degli Studi di Napoli, Italy
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264
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Nakajima H, Liu XW, Wynshaw-Boris A, Rosenthal LA, Imada K, Finbloom DS, Hennighausen L, Leonard WJ. An indirect effect of Stat5a in IL-2-induced proliferation: a critical role for Stat5a in IL-2-mediated IL-2 receptor alpha chain induction. Immunity 1997; 7:691-701. [PMID: 9390692 DOI: 10.1016/s1074-7613(00)80389-1] [Citation(s) in RCA: 214] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Stat5a was identified as a prolactin-induced transcription factor but also is activated by other cytokines, including interleukin-2 (IL-2) and IL-7. We have now analyzed the immune system of Stat5a-deficient mice. Stat5a-/- splenocytes exhibited defective IL-2-induced expression of the IL-2 receptor alpha chain (IL-2R alpha), a protein that together with IL-2R beta and the common cytokine receptor gamma chain (gamma(c)) mediates high-affinity IL-2 binding. Correspondingly, Stat5a-/- splenocytes exhibited markedly decreased proliferation to IL-2, although maximal proliferation was still achieved at IL-2 concentrations high enough to titrate intermediate-affinity IL-2R beta/gamma(c) receptors. Thus, defective Stat5a expression results in diminished proliferation by an indirect mechanism, resulting from defective receptor expression. Correspondingly, we show that Stat5a is essential for maximal responsiveness to antigenic stimuli in vivo, underscoring the physiological importance of IL-2-induced IL-2R alpha expression.
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Affiliation(s)
- H Nakajima
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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265
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Oberg HH, Lengl-Janssen B, Kabelitz D, Janssen O. Activation-induced T cell death: resistance or susceptibility correlate with cell surface fas ligand expression and T helper phenotype. Cell Immunol 1997; 181:93-100. [PMID: 9344501 DOI: 10.1006/cimm.1997.1200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Activated T cells undergo apoptosis when the Fas-antigen (Apo-1, CD95) is ligated by Fas ligand molecules (FasL) or agonistic anti-Fas antibodies. Restimulation of T lymphocytes via the TCR/CD3 complex induces activation-induced cell death (AICD). AICD and Fas-induced cell death are causally related since TCR-induced AICD at least in part depends on Fas/FasL interactions. Thus, restimulation of T cells leads to FasL gene transcription and surface expression. Membrane-bound or secreted FasL molecules then bind to Fas receptors on the same cell or on a neighbor cell to trigger the death signaling cascade. We have compared Fas-mediated apoptosis and AICD in a panel of human T cell clones. While all clones were killed by anti-Fas mAb, several clones were resistant to AICD triggered by anti-TCR/CD3 mAb or superantigen. The pattern of TCR-induced protein tyrosine phosphorylation was comparable in AICD-resistant and -susceptible clones, as was the induction of FasL mRNA. However, significant differences were observed at the level of FasL surface expression which was induced in AICD-susceptible but not in AICD-resistant clones. Cytokine profiles of CD3-stimulated clone cells support the recent observations that AICD sensitivity is restricted to the Th1 subset. However, AICD-resistance is not only associated with the classical Th2 phenotype.
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Affiliation(s)
- H H Oberg
- Department of Immunology, Paul-Ehrlich-Institute, Langen, D-63225, Germany
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266
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Welsh RM, Lin MY, Lohman BL, Varga SM, Zarozinski CC, Selin LK. Alpha beta and gamma delta T-cell networks and their roles in natural resistance to viral infections. Immunol Rev 1997; 159:79-93. [PMID: 9416504 DOI: 10.1111/j.1600-065x.1997.tb01008.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Both alpha beta and gamma delta T-cell populations and natural killer (NK) cells include cytotoxic, interferon (IFN)-gamma-producing lymphocytes that actively respond to viral infections. We show here that all three populations can provide "natural resistance" to viruses very early in infection and describe how the T-cell populations are modulated to provide this function. gamma delta T cells were shown to play a role in controlling vaccinia virus (VV) infections, as VV grew to much higher titers in gamma delta T-cell knockout mice than in normal mice 3-4 days post-infection. Our studies of the alpha beta T-cell responses to viruses revealed an interactive network of T cells that is modulated substantially during systemic infections. There is an induction phase associated with a massive virus-specific CD8 T-cell response, an apoptosis phase during which the T cells become sensitized to activation-induced cell death (AICD), a silencing phase, during which the T-cell number and activation state is reduced, and, finally, a memory phase associated with the very stable preservation of virus-specific memory cytotoxic T-lymphocyte precursors (pCTL). Infection of mice immune to one virus with a heterologous virus leads to a selective expansion of memory CTL cross-reacting between the two viruses, but, after homeostasis is again established, there is a quantitative reduction and qualitative alteration of memory to the first virus. Our results suggest that memory alpha beta T cells cross-reactive between heterologous viruses mediate both immunopathology and protective immunity at early stages of the second virus infection. Thus, memory alpha beta T cells can, like gamma delta T cells and NK cells, provide natural immunity to viral infections.
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Affiliation(s)
- R M Welsh
- Department of Pathology, University of Massachusetts Medical Center, Worcester 01655, USA.
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267
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Brás A, Rodríguez-Borlado L, González-Garcia A, Martínez-A C. Nitric oxide regulates clonal expansion and activation-induced cell death triggered by staphylococcal enterotoxin B. Infect Immun 1997; 65:4030-7. [PMID: 9317003 PMCID: PMC175579 DOI: 10.1128/iai.65.10.4030-4037.1997] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Increased interest has recently been focused on nitric oxide (NO) due to its several biological roles. Apart from being a potential antimicrobial defense and a mediator of autoimmune diseases, NO also appears to be a strong mediator of T-cell responses. In this report, we have characterized the effect of NO on T-cell function. For this purpose, we analyzed in vivo T-cell responses to the bacterial superantigen produced by Staphylococcus aureus, staphylococcal enterotoxin B (SEB), in mice treated with an NO donor (isosorbide dinitrate [ISO]). We show that ISO partially prevents SEB-triggered activation-induced cell death of spleen and lymph node CD4Vbeta8+ T cells but not of CD8Vbeta8+ T cells. SEB-promoted thymic deletion is not abolished by ISO; however, a rapid recovery of thymocyte numbers due to increased double-positive (DP) CD4+ CD8+ thymocyte proliferation was clearly observed in ISO-treated, SEB-injected mice but not in controls (untreated SEB-injected mice). It was also found that ISO inhibits the early SEB-induced cell proliferation (i.e., that found 12 h after SEB injection), accelerating the clonal anergy usually observed 3 days after SEB injection. Inhibition of T-cell proliferation by the NO donor does not appear to be due to inhibition of cytokine production. These results show that NO interferes with apoptosis and facilitates thymic proliferation of DP thymocytes, although it inhibits peripheral T-cell proliferation.
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Affiliation(s)
- A Brás
- Department of Immunology and Oncology, National Center for Biotechnology, CSIC, Universidad Autónoma, Cantoblanco Campus, Madrid, Spain.
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268
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Zhao YX, Holmdahl R, Tarkowski A. Induction of selective anergy by toxic shock syndrome toxin-1 in CD8+ T cells. Immunol Suppl 1997; 92:188-93. [PMID: 9415025 PMCID: PMC1364057 DOI: 10.1046/j.1365-2567.1997.00344.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Interferon-gamma (IFN-gamma) mRNA expression of murine splenic CD8+ T cells in response to toxic shock syndrome toxin-1 (TSST-1) was examined in vitro. In primary response to TSST-1, purified CD8+ cells expressed a low frequency of IFN-gamma mRNA and produced very little interleukin-2 (IL-2) compared with unseparated lymphocytes and purified CD4+ cells. The addition of IL-2 to the cell culture enhanced IFN-gamma mRNA expression in the CD8+ population. Upon restimulation with TSST-1, no IL-2 production and hardly any IFN-gamma mRNA expression were observed in the purified CD8+ lymphoblasts. Exogenously added IL-2 did not increase the IFN-gamma mRNA expression in purified CD8+ blasts exposed to TSST-1. In contrast, stimulation with concanavalin A induced a high frequency of IFN-gamma mRNA in purified CD8+ blasts. Moreover, TSST-1 induced strong IFN-gamma mRNA expression in unseparated T lymphoblasts and purified CD4+ populations. Interestingly, a combined immunocytochemistry and in situ hybridization technique showed a high frequency of CD8+ IFN-gamma mRNA-expressing cells in an unseparated blast population. These results demonstrate that TSST-1 induces a selective anergy within the purified CD8- T-cell compartment and that the IFN-gamma mRNA expression in CD8+ T blasts can be achieved by stimulation of unseparated T cells with TSST-1.
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Affiliation(s)
- Y X Zhao
- Department of Rheumatology and Clinical Immunology, University of Göteborg, Sweden
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269
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Abstract
In the past 2 decades, progressive improvements in the results of organ transplantation as a therapeutic strategy for patients with end-stage organ disease have been achieved due to greater insight into the immunobiology of graft rejection and better measures for surgical and medical management. It is now known that T cells play a central role in the specific immune response of acute allograft rejection. Strategies to prevent T cell activation or effector function are thus all potentially useful for immunosuppression. Standard immunosuppressive therapy in renal transplantation consists of baseline therapy to prevent rejection and short courses of high-dose corticosteroids or monoclonal or polyclonal antibodies as treatment of ongoing rejection episodes. Triple-drug therapy with the combination of cyclosporin, corticosteroids and azathioprine is now the most frequently used immunosuppressive drug regimen in cadaveric kidney recipients. The continuing search for more selective and specific agents has become, in the past decade, one of the priorities for transplant medicine. Some of these compounds are now entering routine clinical practice: among them are tacrolimus (which has a mechanism of action similar to that of cyclosporin), mycophenolate mofetil and mizoribine (which selectively inhibit the enzyme inosine monophosphate dehydrogenase, the rate-limiting enzyme for de novo purine synthesis during cell division), and sirolimus (rapamycin) [which acts on and inhibits kinase homologues required for cell-cycle progression in response to growth factors, like interleukin-2 (IL-2)]. Other new pharmacological strategies and innovative approaches to organ transplantation are also under development. Application of this technology will offer enormous potential not only for the investigation of mechanisms and mediators of graft rejection but also for therapeutic intervention.
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Affiliation(s)
- N Perico
- Department of Transplant Immunology and Innovative Antirejection Therapies, Ospedali Riuniti, Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
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270
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Omata S, Sasaki T, Kakimoto K, Yamashita U. Staphylococcal enterotoxin B induces arthritis in female DBA/1 mice but fails to induce activation of type II collagen-reactive lymphocytes. Cell Immunol 1997; 179:138-45. [PMID: 9268497 DOI: 10.1006/cimm.1997.1164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It has been proposed that superantigens are involved in the pathogenesis of autoimmune diseases. To test the possibility of superantigens inducing arthritis in naive mice, V beta 8-reactive superantigen staphylococcal enterotoxin B (SEB) was injected into naive mice. We used female DBA/1 mice, because they were susceptible to collagen-induced arthritis (CIA), in which the pathogenic T cells were supposed to preferentially use limited V betas of T cell receptors including V beta 8. Mild monoarthritis developed in uninjected hindlimbs of mice administered with SEB in higher frequency (an average incidence of 24%) than the control phosphate-buffered saline-injected mice (4.2%). Autoimmune responses in mice administered with SEB were compared with those in mice developing CIA. However, activation of type II collagen (IIC)-reactive T cells was not detected in SEB-injected mice. Production of autoantibodies, anti-IIC antibody and rheumatoid factor was also undetected. Although exact mechanisms of pathogenesis of this arthritis remain to be known, V beta 8+ T cells were activated for a long period and the unresponsiveness of V beta 8+ T cells was not detected in this strain. From these results, we discuss the pathogenesis of arthritis induced by SEB and the possibility that superantigen may play a role in the induction of autoimmune diseases.
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Affiliation(s)
- S Omata
- Department of Immunology, University of Occupational and Environmental Health, School of Medicine, Kitakyusyu, Japan
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271
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Rouleau M, Mollereau B, Bernard A, Metivier D, Rosenthal-Allieri MA, Charpentier B, Senik A. CD2 induced apoptosis of peripheral T cells. Transplant Proc 1997; 29:2377-8. [PMID: 9270771 DOI: 10.1016/s0041-1345(97)00410-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- M Rouleau
- Cellular Immunology and Transplantation Laboratory, Scientific Cancer Research Institute, Villejuif, France
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272
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Lee WT, Padmanabhan J, Cole-Calkins J. Memory T cell tolerance to superantigens is not due to increased susceptibility to apoptosis. J Autoimmun 1997; 10:357-65. [PMID: 9237799 DOI: 10.1006/jaut.1997.0146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Naive (virgin) and memory T lymphocytes differ markedly in their response to superantigens (SAg). When cultured with the SAg staphylococcal enterotoxin B (SEB), virgin but not memory CD4(+) T cells proliferate and secrete lymphokines. Memory cells do express increased levels of activation markers after interaction with SEB, which suggests that the cells are not ignorant of the SAg. In this report, we have considered whether SEB, rather than activating memory cells, promotes their death by apoptosis. Our results indicate that while in vivo exposure to SEB induces apoptosis, there is no greater level of cell death in the memory cell population relative to virgin cells. Further, elimination of the Fas-mediated cell death pathway does not permit memory cells to be stimulated by SEB. Memory T cells from either Fas-expressing or Fas-deficient (MRL-lpr/lpr) mice are hyporesponsive to SEB. Blockade of Fas/Fas-ligand interactions by a Fas-Fc chimeric protein does not permit BALB/c memory cells to proliferate upon culture with SEB. These results provide evidence that the failure of memory T cells to respond to SEB is not due to cell death and that inactivation (anergy) is the likely fate of these cells when they encounter SEB.
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Affiliation(s)
- W T Lee
- Laboratory of Immunology, Wadsworth Center for Laboratories and Research, Albany, NY 12201-2002, USA.
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273
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Cauley LS, Cauley KA, Shub F, Huston G, Swain SL. Transferable anergy: superantigen treatment induces CD4+ T cell tolerance that is reversible and requires CD4-CD8- cells and interferon gamma. J Exp Med 1997; 186:71-81. [PMID: 9206999 PMCID: PMC2198967 DOI: 10.1084/jem.186.1.71] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Bacterial superantigens induce peripheral unresponsiveness in CD4+ T cell populations that express appropriate Vbeta chains. We have used Vbeta3/Valpha11 T cell receptor transgenic (Tg) mice and the Vbeta3-specific superantigen staphylococcal enterotoxin A (SEA) to further investigate the mechanisms that contribute to such unresponsiveness. As in other models, in vivo exposure to SEA rendered the Tg CD4+ cells unresponsive to subsequent restimulation in vitro with antigen or mitogens. However, when the SEA-treated CD4+ cells were completely purified away from all other contaminating cells, they regained the ability to proliferate and secrete cytokines. Moreover, enriched CD4-CD8- cells from the SEA-treated mice suppressed the responses of fresh control CD4+ cells in mixed cultures indicating that the apparent "anergy" was both transferable and reversible. Further analysis demonstrated that interferon gamma, but not the Fas receptor, played a critical role in the suppression.
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Affiliation(s)
- L S Cauley
- Trudeau Institute, Saranac Lake, New York 12983, USA
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274
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Kishi S, Saijyo S, Arai M, Karasawa S, Ueda S, Kannagi M, Iwakura Y, Fujii M, Yonehara S. Resistance to fas-mediated apoptosis of peripheral T cells in human T lymphocyte virus type I (HTLV-I) transgenic mice with autoimmune arthropathy. J Exp Med 1997; 186:57-64. [PMID: 9206997 PMCID: PMC2198961 DOI: 10.1084/jem.186.1.57] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Transgenic mice carrying the env-pX region of human T lymphocyte virus type I (HTLV-I) develop autoimmune arthropathy in high incidence. Adopting the approach that Fas-mediated apoptosis has a critical function in the elimination of self-reactive T cells, we examined the involvement of this apoptosis in the induction of autoimmunity in HTLV-I transgenic mice. Splenic T cells derived from the transgenic mice were more resistant to apoptosis induced by anti-Fas mAb than those of the nontransgenic mice, whereas no appreciable difference in apoptosis was detected for thymocytes from either mouse's type. The resistance of transgenic T cells may be due to Tax coded in the pX region, since Tax mediates the inhibition of anti-Fas- induced apoptosis in mature T cell line, Jurkat. Among the transgenic mice, the extent of the resistance to Fas-mediated apoptosis was further enhanced in transgenic T cells with disease. These results suggest that the escape of self-reactive T cells from Fas-mediated apoptosis in the periphery, is critical for the development of autoimmune arthropathy in HTLV-I transgenic mice.
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Affiliation(s)
- S Kishi
- Pharmaceutical Basic Research Laboratories JT Inc., Yokohama 236, Japan
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275
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Huang WT, Lin MT, Won SJ. Staphylococcal enterotoxin A-induced fever is associated with increased circulating levels of cytokines in rabbits. Infect Immun 1997; 65:2656-62. [PMID: 9199433 PMCID: PMC175375 DOI: 10.1128/iai.65.7.2656-2662.1997] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Rabbits were injected intravenously with 10 to 100 ng of staphylococcal enterotoxin A (SEA) per kg, and colonic temperatures were monitored. The febrile responses were compared with circulating levels of interferon (IFN), tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-2, and IL-6 just before the injection of SEA. Both colonic temperatures and circulating levels of IFN, TNF, and IL-2 started to rise at 1 to 2 h and reached their peak levels at 3 to 5 h after SEA injection. Both the fever and the increased circulating levels of IFN, TNF, and IL-2 produced by SEA were decreased by pretreatment with indomethacin (a cyclo-oxygenase inhibitor) (15 mg/kg, intraperitoneally), anisomycin (a protein synthesis inhibitor) (15 mg/kg, subcutaneously), or dexamethasone (an effective anti-inflammatory and immunosuppressive agent) (4 mg/kg, intravenously) in rabbits. Rabbits were injected intravenously with 30 ng of SEA per kg on four consecutive days, and colonic temperatures were monitored. Compared to rabbits that received the single injection of SEA, rabbits that received four consecutive injections of SEA showed a lesser increase in circulating levels of IFN, TNF, and IL-2 as well as colonic temperatures in response to an intravenous dose of SEA (30 ng/kg). The data suggest that the prevention of the febrile response elicited by SEA by indomethacin, anisomycin, or dexamethasone is due to prevention by these compounds of the increase in the circulating levels of IFN, TNF, and IL-2. The pyrogenic hyporesponsiveness to repeated injection of SEA is associated with decreased production of these circulating cytokines.
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Affiliation(s)
- W T Huang
- Department of Microbiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China
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276
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Miyatake S, Sakuma M, Saito T. Induction of interleukin-2 unresponsiveness and down-regulation of the JAK-STAT system upon activation through the T cell receptor. Eur J Immunol 1997; 27:1816-23. [PMID: 9247597 DOI: 10.1002/eji.1830270733] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Full activation of T cells with antigen (Ag) and antigen-presenting cells initiates effector functions and proliferation. When T cells are re-stimulated through the T cell receptor (TCR) after a primary stimulation with Ag, growth arrest and cell death are induced. Activation of a T cell clone by cross-linking of TCR induces interleukin (IL)-2 unresponsiveness and ultimately cell death. While the proliferative signal delivered by IL-2 induces c-myc, bcl-2 and cyclin D3 expression, the expression of bcl-2 and cyclin D3 is completely suppressed upon TCR stimulation. Furthermore, TCR stimulation induces a decrease in the protein levels of JAK3 and STAT5, suggesting that IL-2 unresponsiveness and growth arrest of T cells result from down-regulation of JAK3 and STAT5.
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Affiliation(s)
- S Miyatake
- Division of Molecular Genetics, Chiba University School of Medicine, Japan
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277
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Florquin S, Aaldering L. Superantigens: a tool to gain new insight into cellular immunity. RESEARCH IN IMMUNOLOGY 1997; 148:373-86. [PMID: 9443577 DOI: 10.1016/s0923-2494(97)82871-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- S Florquin
- Department of Pathology, Leiden University, The Netherlands
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278
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Utsunomiya Y, Imasawa T, Abe A, Hirano K, Kawamura T, Nagasawa R, Mitarai T, Maruyama N, Sakai O. Bacterial superantigen enhances cytokine production by T-helper lymphocyte subset-2 cells and modifies glomerular lesions in experimental immunoglobulin a nephropathy. Clin Exp Nephrol 1997. [DOI: 10.1007/bf02479906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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279
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Varadhachary AS, Perdow SN, Hu C, Ramanarayanan M, Salgame P. Differential ability of T cell subsets to undergo activation-induced cell death. Proc Natl Acad Sci U S A 1997; 94:5778-83. [PMID: 9159150 PMCID: PMC20856 DOI: 10.1073/pnas.94.11.5778] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Human T cell clones were analyzed for their susceptibility to activation-induced cell death (AICD) in response to CD3/T cell receptor ligation. AICD was observed only in Th1 clones and was Fas-mediated, whereas Th2 clones resisted AICD. Analysis of a panel of Th0 clones, characterized by their ability to secrete both Th1 and Th2 cytokines, revealed that this subset included both AICD-sensitive (type A) and -resistant (type B) clones. Resistance to AICD by Th2 and Th0-type B clones was not due to lack of expression of either Fas receptor or its ligand. Paradoxically, the AICD-resistant clones were susceptible to apoptosis when Fas receptor was directly ligated by anti-Fas antibodies. However, prior activation of the resistant clones by monoclonal antibodies to CD3/TCR complex induced resistance against Fas-mediated apoptosis. Thus, the Fas-FasL pathway is critical for the induction of AICD in T cells, and moreover this pathway can be negatively regulated in the AICD-resistant clones by signals that are generated from ligation of the CD3/TCR complex.
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Affiliation(s)
- A S Varadhachary
- Department of Microbiology and Immunology, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140, USA
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280
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Abstract
Abstract
Anti-CD3 monoclonal antibodies (MoAbs) and glucocorticoid hormones induce apoptosis in immature thymocytes and peripheral T lymphocytes. This process is inhibited by a number of growth factors, including interleukin-2 (IL-2), IL-3, and IL-4, as well as by triggering of the adhesion molecule CD44, which would indicate that signals generated by membrane receptors can modulate the survival of lymphoid cells. To investigate whether triggering of CD2 may also affect apoptosis in lymphoid cells, we analyzed the effect of stimu-lation with anti-CD2 MoAbs on T-cell apoptosis induced by two stimuli, anti-CD3 MoAbs and dexamethasone (DEX), using a hybridoma T-cell line and a T-helper cell clone. The results show that CD2 engagement decreased anti-CD3 MoAb-induced apoptosis, but did not influence DEX-induced cell death. Furthermore, the decrease appeared to be related to the expression of Fas/APO-1 (CD95) and Fas-ligand (Fas-L). In fact, we show that CD2 stimulation inhibits apoptosis by preventing the CD3-induced upregulation of Fas and Fas-L in a Fas-dependent experimental system. These data suggest that a costimulatory molecule may control a deletion pathway and may therefore contribute to the regulation of peripheral tolerance.
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281
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Abstract
Anti-CD3 monoclonal antibodies (MoAbs) and glucocorticoid hormones induce apoptosis in immature thymocytes and peripheral T lymphocytes. This process is inhibited by a number of growth factors, including interleukin-2 (IL-2), IL-3, and IL-4, as well as by triggering of the adhesion molecule CD44, which would indicate that signals generated by membrane receptors can modulate the survival of lymphoid cells. To investigate whether triggering of CD2 may also affect apoptosis in lymphoid cells, we analyzed the effect of stimu-lation with anti-CD2 MoAbs on T-cell apoptosis induced by two stimuli, anti-CD3 MoAbs and dexamethasone (DEX), using a hybridoma T-cell line and a T-helper cell clone. The results show that CD2 engagement decreased anti-CD3 MoAb-induced apoptosis, but did not influence DEX-induced cell death. Furthermore, the decrease appeared to be related to the expression of Fas/APO-1 (CD95) and Fas-ligand (Fas-L). In fact, we show that CD2 stimulation inhibits apoptosis by preventing the CD3-induced upregulation of Fas and Fas-L in a Fas-dependent experimental system. These data suggest that a costimulatory molecule may control a deletion pathway and may therefore contribute to the regulation of peripheral tolerance.
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282
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Tripp RA, Hamilton-Easton AM, Cardin RD, Nguyen P, Behm FG, Woodland DL, Doherty PC, Blackman MA. Pathogenesis of an infectious mononucleosis-like disease induced by a murine gamma-herpesvirus: role for a viral superantigen? J Exp Med 1997; 185:1641-50. [PMID: 9151901 PMCID: PMC2196306 DOI: 10.1084/jem.185.9.1641] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/1996] [Revised: 02/25/1997] [Indexed: 02/04/2023] Open
Abstract
The murine gamma-herpesvirus 68 has many similarities to EBV, and induces a syndrome comparable to infectious mononucleosis (IM). The frequency of activated CD8+ T cells (CD62L(lo)) in the peripheral blood increased greater than fourfold by 21 d after infection of C57BL/6J (H-2(b)) mice, and remained high for at least a further month. The spectrum of T cell receptor usage was greatly skewed, with as many as 75% of the CD8+ T cells in the blood expressing a Vbeta4+ phenotype. Interestingly, the Vbeta4 dominance was also seen, to varying extents, in H-2(k), H-2(d), H-2(u), and H-2(q) strains of mice. In addition, although CD4 depletion from day 11 had no effect on the Vbeta4 bias of the T cells, the Vbeta4+CD8+ expansion was absent in H-2IA(b)-deficient congenic mice. However, the numbers of cycling cells in the CD4 antibody-depleted mice and mice that are CD4 deficient as a consequence of the deletion of MHC class II, were generally lower. The findings suggest that the IM-like disease is driven both by cytokines provided by CD4+ T cells and by a viral superantigen presented by MHC class II glycoproteins to Vbeta4+CD8+ T cells.
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Affiliation(s)
- R A Tripp
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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283
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Lima M, Teixeira MDA, Dos Santos AH, Queirós ML, Justiça B. Decreased expression of bcl-2 (p26) in CD8(+) lymphocytes of patients with T-cell lymphoproliferative disorders of large granular lymphocytes. Hematol Oncol 1997; 15:81-91. [PMID: 9375033 DOI: 10.1002/(sici)1099-1069(199705)15:2<81::aid-hon602>3.0.co;2-q] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The bcl-2 oncogene has been involved in the genesis of various B-cell neoplasms by means of encoding for p26, an apoptosis suppressor oncoprotein. The expression of p26 in lymphoproliferative disorders of large granular lymphocytes (LDLGL), a group of diseases whose mechanism leading to lymphocyte expansion is not yet clear, was not previously characterized. In order to further understand the biology of LDLGL, we compared the expression of p26 in CD8(+) lymphocytes of patients with CD3(+) LDLGL with that observed in normal individuals, patients with viral infection and patients with CD4(+) lymphoid neoplasms. We observed that upregulation of bcl-2 expression is not involved in the genesis of lymphocyte expansion in CD3(+) LDLGL. By contrast, when compared to normal peripheral blood counterparts, CD8(+, bright) lymphocytes of patients with LDLGL express low levels of p26 whereas CD8(+, dim) lymphocytes express normal or only slightly reduced levels of this oncoprotein. A similar pattern of expression of p26 was found in situations in which CD8(+) lymphocytes represent reactive activated cells.
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Affiliation(s)
- M Lima
- St. Antonio's Hospital, Porto, Portugal
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284
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Fuse Y, Nishimura H, Maeda K, Yoshikai Y. CD95 (Fas) may control the expansion of activated T cells after elimination of bacteria in murine listeriosis. Infect Immun 1997; 65:1883-91. [PMID: 9125576 PMCID: PMC175236 DOI: 10.1128/iai.65.5.1883-1891.1997] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
CD95 (Fas) is known to mediate activation-induced T-cell death by apoptosis. To understand the role of CD95 during the course of bacterial infection, we examined the kinetics of alphabeta and gammadelta T cells in the peritoneal cavities and livers of 5-week-old CD95-defective MRL/lpr mice after an intraperitoneal infection with Listeria monocytogenes. The number of bacteria in the spleen decreased to an undetectable level by day 10 after infection with 7 x 10(3) Listeria cells similar to the number in MRL/+/+ mice. The number of alphabeta T cells expressing CD44 and CD95 reached a maximum in the peritoneal cavity on day 6 after listerial infection and thereafter decreased gradually in MRL/+/+ mice, whereas CD44+ alphabeta T cells without CD95 expression continued to increase throughout the course of listerial infection in MRL/lpr mice. Freshly isolated T cells from MRL/+/+ mice infected with L. monocytogenes 10 days previously showed DNA fragmentation with apoptosis, whereas such fragmentation was not prominent in T cells from infected MRL/lpr mice. In correlation with the increased number of CD44+ alphabeta T cells, Listeria-specific T-cell proliferation of peritoneal exudate cells was significantly greater in MRL/lpr mice than in MRL/+/+ mice on day 10 after listerial infection. In contrast to alphabeta T cells, gammadelta T cells increased in number only transiently in the peritoneal cavity and liver after listerial infection in both MRL/lpr mice and MRL/+/+ mice. These results suggest that CD95-mediated cell death with apoptosis may be involved in termination of the alphabeta-T-cell-mediated immune response after the battle against L. monocytogenes has been won, whereas gammadelta T cells may undergo apoptosis independently of CD95 during the course of listerial infection.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- Apoptosis/immunology
- CD3 Complex/immunology
- Cell Division/immunology
- Colony Count, Microbial
- DNA Fragmentation
- Female
- Flow Cytometry
- Hyaluronan Receptors/immunology
- Kinetics
- Listeria monocytogenes
- Listeriosis/immunology
- Liver/immunology
- Liver/microbiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred MRL lpr
- Peritoneal Cavity/cytology
- Peritoneum/immunology
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Receptors, Antigen, T-Cell, gamma-delta/physiology
- Spleen/microbiology
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- fas Receptor/immunology
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Affiliation(s)
- Y Fuse
- Department of Internal Medicine, Nagoya University Branch Hospital, Nagoya University School of Medicine, Japan
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285
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Shoukry NH, Lavoie PM, Thibodeau J, D'Souza S, Sekaly RP. MHC class II-dependent peptide antigen versus superantigen presentation to T cells. Hum Immunol 1997; 54:194-201. [PMID: 9297538 DOI: 10.1016/s0198-8859(97)00074-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
T lymphocytes expressing the CD4 coreceptor can be activated by two classes of major histocompatibility complex (MHC) class II-bound ligands. The elaboration of a conventional T-cell mediated immune response involves recognition of an antigenic peptide bound to the MHC class II molecules by a T-cell receptor (TCR) specific to that particular antigen. Conversely, superantigens (SAgs) also bind to MHC class II molecules and activate T cells, leading to a completely different functional outcome; indeed, SAg-responsive T cells die through apoptosis following stimulation. Superantigens are proteins that are secreted by various bacteria. They interact with the TCR using molecular determinants that are distinct from the residues involved in the recognition of nominal antigenic peptides. Despite the similarities between the recognition of the two classes of ligands by the TCR, considerable structural difference is observed. Here, we discuss the current knowledge on the presentation of SAgs to T cells and compare the different aspects of the SAg response with the recognition of antigenic peptide/MHC complexes.
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Affiliation(s)
- N H Shoukry
- Laboratoire d'Immunologie, Institut de Recherches Cliniques de Montreal (IRCM), Quebec, Canada
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286
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Abe J, Onimaru M, Matsumoto S, Noma S, Baba K, Ito Y, Kohsaka T, Takeda T. Clinical role for a superantigen in Yersinia pseudotuberculosis infection. J Clin Invest 1997; 99:1823-30. [PMID: 9109426 PMCID: PMC508006 DOI: 10.1172/jci119349] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Yersinia pseudotuberculosis is an enteric pathogen that causes a variety of clinical symptoms in the human. Recently, we reported the production of a superantigen (Y. pseudotuberculosis-derived mitogen, YPM) by this organism and characterized the gene structure of ypm. To further study the potential pathogenic role of YPM in Y. pseudotuberculosis infection, we assayed IgG anti-YPM antibodies and T cell antigen receptor-Vbeta expression of the T cells in peripheral blood and in mesenteric lymph node in patients acutely infected with Y. pseudotuberculosis. 20 out of 33 patients (61%) had an elevated antibody titer compared with healthy controls (P = 0.0001). Patients with systemic symptoms such as lymphadenopathy, transient renal dysfunction, and arthritis had significantly higher titers of anti-YPM than patients with gastrointestinal tract symptoms alone. T cells bearing the Vbeta3 gene segment were significantly increased (P = 0.009) among acute phase patients compared with healthy children. During the convalescence phase of the illness, there was a reduction in the abnormal level of Vbeta3 T cells. Moreover, in the mesenteric lymph node, an elevated level of Vbeta3 T cells compared with peripheral blood and a sequence diversity in the junctional region of the T cell antigen receptor beta-chain containing Vbeta3 element was observed in one patient. Together, these findings suggest that YPM was produced in vivo and played an important role in the pathogenesis of Y. pseudotuberculosis infection.
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Affiliation(s)
- J Abe
- Department of Child Ecology, The National Children's Hospital Medical Research Center, Setagaya-ku, Tokyo, Japan.
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287
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Doria G, Mancini C, Utsuyama M, Frasca D, Hirokawa K. Aging of the recipients but not of the bone marrow donors enhances autoimmunity in syngeneic radiation chimeras. Mech Ageing Dev 1997; 95:131-42. [PMID: 9152966 DOI: 10.1016/s0047-6374(97)01871-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Young and old mice have been lethally irradiated and injected with syngeneic bone marrow cells from young or old donors to investigate whether self reactivity in old mice results from age-related damage of the radioresistant stromal cells and/or of the bone marrow hematopoietic cells. Thymus and spleen cell repopulations and mitotic responses at 3 months after irradiation are lower in old than in young recipients, suggesting age-related accumulation of stromal cell damage in the thymus as well as in other central and peripheral lymphoid tissues. The same efficiency of bone marrow cells from young and old donors to repopulate the thymus and spleen in recipients of equal age rules out the detrimental effects of aging on stem cells as well as T and B cell precursors. The serum concentration of auto-antibody and glomerular lesions at 3 and 9 months after irradiation were more pronounced in old than in young recipients and displayed no difference in recipients of equal age, regardless of the age of the bone marrow cell donors. These findings support the possibility that age-related damage of stromal cells induces disregulation of the immune system leading to autoimmune phenomena.
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Affiliation(s)
- G Doria
- Laboratory of Immunology, AMB-PRO-TOSS, ENEA CR Casaccia, Rome, Italy
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288
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Pape KA, Kearney ER, Khoruts A, Mondino A, Merica R, Chen ZM, Ingulli E, White J, Johnson JG, Jenkins MK. Use of adoptive transfer of T-cell-antigen-receptor-transgenic T cell for the study of T-cell activation in vivo. Immunol Rev 1997; 156:67-78. [PMID: 9176700 DOI: 10.1111/j.1600-065x.1997.tb00959.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Adoptive transfer of TCR-transgenic T cells uniformly expressing an identifiable TCR of known peptide/MHC specificity can be used to monitor the in vivo behavior of antigen-specific T cells. We have used this system to show that naive T cells are initially activated within the T-cell zones of secondary lymphoid tissue to proliferate in a B7-dependent manner. If adjuvants or inflammatory cytokines are present during this period, enhanced numbers of T cells accumulate, migrate into B-cell-rich follicles, and acquire the capacity to produce IFN-gamma and help B cells produce IgG2a. If inflammation is absent, most of the initially activated antigen-specific T cells disappear without entering the follicles, and the survivors are poor producers of IL-2 and IFN-gamma. Our results indicate that inflammatory mediators play a key role in regulating the anatomic location, clonal expansion, survival and lymphokine production potential of antigen-stimulated T cells in vivo.
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Affiliation(s)
- K A Pape
- Department of Microbiology, University of Minnesota, Minneapolis 55455, USA
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289
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Sasaki T, Fujiyama Y, Ide T, Kakimoto K, Niwakawa M, Bamba T, Tokiyoshi S, Onoue K. Prevention of collagen-induced arthritis with the superantigen, Staphylococcal enterotoxin B. PATHOPHYSIOLOGY 1997. [DOI: 10.1016/s0928-4680(96)00143-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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290
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Wack A, Corbella P, Harker N, Crispe IN, Kioussis D. Multiple sites of post-activation CD8+ T cell disposal. Eur J Immunol 1997; 27:577-83. [PMID: 9079795 DOI: 10.1002/eji.1830270302] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Antigen-triggered activation of T cells leads to a sequence of differentiation steps including up-regulation of activation markers, blast formation, proliferation, delivery of effector functions, and ultimately apoptosis. It is still controversial in which anatomical site activation-induced apoptosis and elimination of T cells occur. To address this question, we used mice transgenic for a T cell receptor (F5) specific for an influenza virus nucleoprotein peptide (NP68) presented on the major histocompatibility complex H-2 Db molecule. Accumulation and apoptosis of T cells was studied using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling in situ combined with immunohistology after intraperitoneal injection of the cognate peptide into F5 mice which are wild type or deficient for Rag-1. After 4 days of peptide treatment, large perivascular infiltrations of CD8+ cells were observed in liver, lung, and kidney of F5 mice. CD8+ cell numbers were also increased in skin and small intestine, but not in brain or heart muscle of peptide-treated animals. The infiltrating CD8+ cells show an increased percentage of apoptosis in liver, lung and, most strikingly, the kidney. These data suggest that in the F5 system, T cell disposal after activation occurs in a number of organs. Essentially identical findings were obtained in Rag-1(+/+) and Rag-1(-/-) F5 mice, suggesting that the deletion mechanism did not involve other T or B cells.
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Affiliation(s)
- A Wack
- Division of Molecular Immunology, National Institute for Medical Research, London, GB
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291
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Luther SA, Gulbranson-Judge A, Acha-Orbea H, MacLennan IC. Viral superantigen drives extrafollicular and follicular B cell differentiation leading to virus-specific antibody production. J Exp Med 1997; 185:551-62. [PMID: 9053455 PMCID: PMC2196032 DOI: 10.1084/jem.185.3.551] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Mouse mammary tumor virus (MMTV[SW]) encodes a superantigen expressed by infected B cells. It evokes an antibody response specific for viral envelope protein, indicating selective activation of antigen-specific B cells. The response to MMTV(SW) in draining lymph nodes was compared with the response to haptenated chicken gamma globulin (NP-CGG) using flow cytometry and immunohistology. T cell priming occurs in both responses, with T cells proliferating in association with interdigitating dendritic cells in the T zone. T cell proliferation continues in the presence of B cells in the outer T zone, and B blasts then undergo exponential growth and differentiation into plasma cells in the medullary cords. Germinal centers develop in both responses, but those induced by MMTV(SW) appear later and are smaller. Most T cells activated in the T zone and germinal centers in the MMTV(SW) response are superantigen specific and these persist for weeks in lymph nodes draining the site MMTV(SW) injection: this contrasts with the selective loss of superantigen-specific T cells from other secondary lymphoid tissues. The results indicate that this viral superantigen, when expressed by professional antigen-presenting cells, drives extrafollicular and follicular B cell differentiation leading to virus-specific antibody production.
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Affiliation(s)
- S A Luther
- Ludwig Institute for Cancer Research, University of Lansanne, Epalinges
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292
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Chou MC, Lee SC, Lin YS, Lei HY. V beta 8+CD4-CD8- subpopulation induced by staphylococcal enterotoxin B. Immunol Lett 1997; 55:85-91. [PMID: 9143938 DOI: 10.1016/s0165-2478(97)02689-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Injection of staphylococcal enterotoxin B (SEB) into BALB/c mice induced the depletion of V beta 8+ T-cells which were either V beta 8+CD4+ or V beta 8+CD8+ cells. The CD8 molecule on V beta 8+CD8+ cells was found to decrease at 72 h after SEB treatment while the V beta 8 molecule on V beta 8+ cells or CD4 molecule on V beta 8+CD4+ cells was not affected. Furthermore, a subpopulation of V beta 8+CD4-CD8- T-cells was also induced after SEB-priming. This subpopulation can be found in spleen or lymph nodes. It was small in size and constituted the major part of V beta 8+ cells in lymph nodes at 72 h after SEB-priming. Some of the V beta 8+CD4-CD8- T-cells might be autoreactive because they could be stimulated to proliferative by syngenic mitomycin C-treated splenocytes.
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Affiliation(s)
- M C Chou
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
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293
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Belfrage H, Dohlsten M, Hedlund G, Kalland T. Prevention of superantigen-induced down-regulation of T-cell mediated cytotoxic activity by IL-2 in vivo. Immunology 1997; 90:183-8. [PMID: 9135545 PMCID: PMC1456741 DOI: 10.1046/j.1365-2567.1997.00030.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Administration of staphylococcal enterotoxin A (SEA) to mice induces profound activation, cytokine production and cytotoxic activity of both CD4+ and CD8+ T cells, but subsequently activated cells are deleted or become anergic. This study demonstrates that administration of interleukin-2 (IL-2) can prevent sea-induced hyporesponsiveness in CD8+ cytotoxic T lymphocytes (CTL). Repeated injections with sea every fourth day resulted in severely reduced cytotoxic activity in the spleen, which correlated with a reduced number of sea-responsive T-cell receptor (TCR)-V beta 11+ CD8+ cells. Studies of purified TCR-V beta 11+ CD8+ cells showed that they possessed intact cytotoxic activity per cell compared with cells from mice given a single injection of SEA, indicating that deletion was the main mechanism for the reduced cytotoxic activity. Combined treatment with SEA and IL-2 increased the number of cytotoxic cells in the spleen after each SEA injection and prevented the down-regulation of cytotoxic activity. Increased cytotoxic activity could be related to increased number and proliferation of CD8+ IL-2R alpha + cells, suggesting that administration of IL-2 maintained IL-2 responsiveness among CD8+ cells. Studies of sorted TCR-V beta 11+ CD8+ cells demonstrated that combined treatment with SEA and IL-2 also increased cytotoxic activity per cell compared with treatment with SEA alone. Taken together, IL-2 administration in vivo augmented SEA-induced expansion of T cells as well as the cytotoxic activity per CTL, and prevented SEA-induced cell deletion.
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Affiliation(s)
- H Belfrage
- Department of Cell and Molecular Biology, Lund University, Sweden
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294
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Kuschnaroff L, Valckx D, Froyen G, Martens E, Groenen M, Goebels J, Heremans H, Waer M. Opposing effects of cyclosporin A and anti-interferon-gamma antibodies on immune tolerance mechanisms. Transplant Proc 1997; 29:1156-7. [PMID: 9123248 DOI: 10.1016/s0041-1345(96)00502-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- L Kuschnaroff
- Laboratory for Experimental Transplantation, Rega Institute, University of Leuven, Belgium
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295
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Fan J, Nanki T, Miyasaka N, Kohsaka H. Double-negative BV8S3 T cells expanded in MRL lpr/lpr lymph nodes conserve TCRBJ gene usage of single-positive BV8S3 T cells. Microbiol Immunol 1997; 41:253-60. [PMID: 9130237 DOI: 10.1111/j.1348-0421.1997.tb01197.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Enlarged lymph nodes of mice with lpr mutation consist predominantly of CD4- CD8- (double-negative: DN) T cells. Among them, TCRBV8S3 (V beta 8.3) T cells are overrepresented as compared to those in single-positive (SP) T cells. To address the question of whether the expansion of oligoclonal T cells is responsible for the increase in TCRBV8S3 cells, we examined the TCRBJ gene repertoires of BV8S3 DN and SP T cells from multiple MRL lpr/lpr mice. The BJ repertoires of BV3 (V beta 3), BV8S1 (V beta 8.1) and BV8S2 (V beta 8.2) were studied for comparison with those of BV8S3 T cells. The employed method, which was based on a PCR-ELISA technique, was newly developed and allowed us to make a precise quantitation of TCRBJ gene usage of the multiple lymphocyte samples. The results showed that there were no biases of the BJ gene usage by BV8S3 DN T cells as well as other BV T cells. Furthermore, the BJ gene usage of CD4 and CD8 BV8S3 T cells was conserved by the DN T cells. It is suggested that the BV8S3 DN T cells were not expanded by specific antigens. The expansion may result from aberrant regulation specific to the BV8S3-expressing T cells.
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Affiliation(s)
- J Fan
- First Department of Internal Medicine, Faculty of Medicine, Tokyo Medical and Dental University, Japan
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296
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Marchetti P, Decaudin D, Macho A, Zamzami N, Hirsch T, Susin SA, Kroemer G. Redox regulation of apoptosis: impact of thiol oxidation status on mitochondrial function. Eur J Immunol 1997; 27:289-96. [PMID: 9022031 DOI: 10.1002/eji.1830270142] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The probability that a cell will undergo apoptosis is in part dictated by the cellular redox potential, which is mainly determined by the reduction and oxidation of thiol residues on glutathione and proteins. We and others have recently shown that mitochondria play a critical role in the apoptotic cascade. Here, we address the question as to whether thiol modification regulates apoptosis and in which cellular compartment apoptosis-regulatory thiols are localized. To resolve this problem, we employed the divalent thiol-reactive agent diamide, which causes thiol cross-linking and thus mimics disulfide bridge formation, and a panel of monovalent thiol-reactive compounds (which impede disulfide bridge formation due to thiol oxidation), one of which is specifically targeted to the mitochondrial matrix. Our data indicate that thymocyte apoptosis induced by diamide mimics natural apoptosis in the sense that mitochondrial transmembrane potential (delta psi(m)) disruption precedes nuclear chromatin degradation; that monovalent thiol-reactive compounds inhibit apoptosis induced by diamide, glucocorticoids, irradiation, and topoisomerase inhibition; that the critical thiols determining cell fate after exposure to diamide, glucocorticoids, or DNA damage are likely to be located in the mitochondrial matrix; and that thiol oxidation and reduction are critical for apoptosis induction by some stimuli (glucocorticoids, DNA damage), but not by Fas/CD95 cross-linking. Taken together, these findings suggest that, at least in some pathways of apoptosis, mitochondrial thiols constitute a critical sensor of the cellular redox potential.
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297
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Mouse Mammary Tumor Virus: Immunological Interplays between Virus and Host **This article was accepted for publication on 1 October 1996. Adv Immunol 1997. [DOI: 10.1016/s0065-2776(08)60743-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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298
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Domiati-Saad R, Lipsky PE. B cell superantigens: potential modifiers of the normal human B cell repertoire. Int Rev Immunol 1997; 14:309-24. [PMID: 9186783 DOI: 10.3109/08830189709116522] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Staphylococcal protein A (SPA), HIV gp120, and staphylococcal enterotoxins (SE) are B cell superantigens that induce VH specific B cell responses. In addition, the red blood cell antigens, i/I, have some features of a B cell superantigen. Binding of SPA, SE and HIV gp120 are VH family specific, whereas binding of i/I is VH gene specific. SPA and HIV gp120 function by stimulating VH3-expressing B cells, whereas SE appear to function by enhancing survival of the appropriate VH-expressing B cells. Moreover, HIV gp120 has been shown to delete VH3-expressing B cells. In this review, we describe evidence that shows how these superantigens may play a role in shaping the normal B cell repertoire.
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Affiliation(s)
- R Domiati-Saad
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas 75235, USA
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299
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Aoki Y, Yoshikai Y. Further clonal expansion of T cells upon rechallenge of superantigen staphylococcal enterotoxin A. Microbiol Immunol 1997; 41:337-43. [PMID: 9159408 DOI: 10.1111/j.1348-0421.1997.tb01210.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Superantigens are known to induce clonal anergy and/or deletion in reactive T cells peripherally. This study was undertaken to investigate the T-cell status early after exposure to staphylococcal enterotoxin A (SEA) in vivo and in vitro. At the peak of clonal expansion following the administration of 5 microg SEA (i.e., 2 days after the injection), C57BL/6 mice were rechallenged with the same dose of SEA in vivo. The secondary stimulation augmented clonal expansion of the T cells bearing Vbeta3 and Vbeta11 in both CD4+ and CD8+ populations. In vitro restimulation of the spleen cells taken from the SEA-primed mice also induced further expansion of the Vbeta3+ T cells during 2 days of culturing, whereas without restimulation, a marked reduction of Vbeta3+ T cells occurred. The spleen cells from the SEA-primed mice were hyper-reactive to in vitro restimulation with SEA as measured by 3H-TdR uptake on day 1 of culturing, but augmented proliferation leveled off thereafter. By day 3, the values of 3H-TdR uptake were less than 20% of those of the controls in which spleen cells from native mice were stimulated with SEA in vitro. These results suggest that T cells exposed to SEA in vivo are still capable of proliferating upon SEA rechallenge, but subsequently, the proliferation starts to wane.
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Affiliation(s)
- Y Aoki
- Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Showa-ku, Aichi, Japan
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300
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Abstract
In the last 10 years many of the superantigens of the microbial world have been defined and the mechanisms of cellular interaction between lymphocytes and antigen presenting cells has been elucidated in great detail. The consequences of superantigen stimulation of the immune system, though less well defined, can be considered in three separate stages: T-cell proliferation, apoptosis, and recovery. Understanding these stages may explain why diverse superantigens may cause markedly different clinical processes ranging from acute shock to chronic arthritis and may form the basis for novel treatments of these diverse diseases.
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Affiliation(s)
- D L Stevens
- Veterans Affairs Medical Center, Boise, Idaho 83702, USA
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