scholarly journals A tumor-suppressor function for Fas (CD95) revealed in T cell-deficient mice.

1996 ◽  
Vol 184 (3) ◽  
pp. 1149-1154 ◽  
Author(s):  
S L Peng ◽  
M E Robert ◽  
A C Hayday ◽  
J Craft

Fas (CD95) and its ligand are central regulatory molecules in hematopoietic cells. Previous studies have suggested a role for Fas in the regulation of tumor progression, but Fas has not yet been conclusively identified as a tumor suppressor. Fas-deficient individuals lack malignant tumors, perhaps because of regulation by T cells. To investigate such a possibility, mice deficient in both T cells and Fas were generated, and they were found to develop severe B cell dysregulation characterized by malignant, lethal B cell lymphoma. Lymphoma arose from a monoclonal B220+CD19-CD5-CD23- B cell secreting immunoglobulin M, kappa rheumatoid factor. In contrast, animals containing alpha beta T cells, gamma delta T cells, and/or functional Fas suppressed the development of lymphoma. These data indicate that Fas functions as a tumor suppressor, and identifies roles for both alpha beta T cells and gamma delta T cells in Fas-independent tumor regulation.

1994 ◽  
Vol 91 (1) ◽  
pp. 345-349 ◽  
Author(s):  
M. Tsuji ◽  
P. Mombaerts ◽  
L. Lefrancois ◽  
R. S. Nussenzweig ◽  
F. Zavala ◽  
...  

1997 ◽  
Vol 113 (1-3) ◽  
pp. 373-375 ◽  
Author(s):  
Marian Szczepanik ◽  
Laurel R. Anderson ◽  
Hiroko Ushio ◽  
Wlodzimierz Ptak ◽  
Michael J. Owen ◽  
...  

1996 ◽  
Vol 183 (5) ◽  
pp. 2271-2282 ◽  
Author(s):  
L Wen ◽  
W Pao ◽  
F S Wong ◽  
Q Peng ◽  
J Craft ◽  
...  

The production of class-switched antibodies, particularly immunoglobulin (Ig) G1 and IgE, occurs efficiently in T cell receptor (TCR) alpha-/- mice that are congenitally devoid of alpha/beta T cells. This finding runs counter to a wealth of data indicating that IgG1 and IgE synthesis are largely dependent on the collaboration between B and alpha/beta T cells. Furthermore, many of the antibodies synthesized in TCR alpha-/- mice are reactive to a similar spectrum of self-antigens as that targeted by autoantibodies characterizing human systemic lupus erythematosus (SLE). SLE, too, is most commonly regarded as an alpha/beta T cell-mediated condition. To distinguish whether the development of autoantibodies in TCR alpha-/- mice is due to an intrinsic de-regulation of B cells, or to a heretofore poorly characterized collaboration between B and "non-alpha/beta T" cells, the phenotype has been reconstituted by transfer of various populations of B and non-alpha/beta T cells including cloned gamma/delta T cells derived from TCR alpha-/- mice, to severe combined immunodeficient (SCID) mice. The results establish that the reproducible production of IgG1 (including autoantibodies) is a product of non-alpha/beta T cell help that can be provided by gamma/delta T cells. This type of B-T collaboration sustains the production of germinal centers, lymphoid follicles that ordinarily are anatomical signatures of alpha/beta T-B cell collaboration. Thus, non-alpha/beta T cell help may drive Ig synthesis and autoreactivity under various circumstances, especially in cases of alpha/beta T cell immunodeficiency.


1992 ◽  
Vol 89 (2) ◽  
pp. 653-657 ◽  
Author(s):  
I. Correa ◽  
M. Bix ◽  
N. S. Liao ◽  
M. Zijlstra ◽  
R. Jaenisch ◽  
...  

1991 ◽  
Vol 174 (1) ◽  
pp. 293-296 ◽  
Author(s):  
M Iwashima ◽  
M M Davis ◽  
Y H Chien

CD4 and CD8 have been useful surface markers for alpha/beta T cell maturation. In an alpha/beta T cell receptor (TCR) transgenic SCID mice system, it has been shown that alpha/beta TCR alone is sufficient to induce CD4 and CD8 surface expression on thymic T cells. Although the late embryonic thymic gamma/delta T cells are predominately single and double positive, it has not been clear if gamma/delta TCR has a similar capacity. In this study, we show that when transgenes encoding the earliest embryonic gamma/delta TCR are coexpressed with the SCID defect, the gamma/delta transgenes promote the appearance of both the CD4-8- and CD4+8+ T cells in the thymus. Furthermore, the expression of CD4 and CD8 does not require continuous surface gamma/delta TCR expression. These results indicate that gamma/delta TCR alone can promote the CD4/8 surface expression, and may suggest a role for gamma/delta T cells in initiating normal thymic ontogeny.


1995 ◽  
Vol 182 (3) ◽  
pp. 891-895 ◽  
Author(s):  
H Arase ◽  
S Ono ◽  
N Arase ◽  
S Y Park ◽  
K Wakizaka ◽  
...  

The relationship between the structure of the T cell antigen receptor (TCR)-CD3 complex and development of NK1.1+ T cells was investigated. The TCR complex of freshly isolated NK1.1+ TCR-alpha/beta+ thymocytes contained CD3 zeta homodimers and CD zeta-FcR gamma heterodimers, whereas that of the majority of NK1.1- T cells did not contain FcR gamma. The function of CD3 zeta and FcR gamma in the development of NK1.1+ T cells was determined by analyzing CD3 zeta- and FcR gamma-deficient mice. The NK1.1+ T cells from wild-type and CD3 zeta-deficient mice had equal levels of CD3 expression. However, the development of NK1.1+ TCR-alpha/beta+ T cells was almost completely disrupted in thymus and spleen in CD3 zeta-deficient mice, whereas no alteration was observed in FcR gamma-deficient mice. In contrast, the number of novel NK1.1+ TCR-gamma/delta+ thymocytes expressing a surface phenotype similar to NK1.1+ TCR-alpha/beta+ thymocytes increased approximately six times in CD3 zeta-deficient mice. These findings establish the distinct roles of the CD3 zeta chain in the development of the following different thymic T cell compartments: NK1.1- TCR+, NK1.1+ TCR-alpha/beta+, and NK1.1+ TCR-gamma/delta+ thymocytes, which cannot be replaced by CD3 eta or FcR gamma chains.


1993 ◽  
Vol 178 (3) ◽  
pp. 985-996 ◽  
Author(s):  
M J Skeen ◽  
H K Ziegler

Peritoneal gamma/delta T cells from Listeria-immune mice show an enhanced potential to expand when restimulated with antigens or mitogens in vitro (see companion paper [Skeen, M. J., and H. K. Ziegler. 1993. J. Exp. Med. 178:971]). When cocultured with peritoneal alpha/beta T cells, the gamma/delta T cell population expanded preferentially even when the in vitro stimulus was specific for the alpha/beta T cell population. Purified gamma/delta T cells did not respond to alpha/beta T cell-specific stimuli. If isolated T cell subsets were recombined in cell mixing experiments, the resulting proliferative response was greater than additive. Irradiated alpha/beta T cells could enhance the proliferation of responding gamma/delta T cells, but the effect was unidirectional; i.e., irradiated gamma/delta T cells did not stimulate responding gamma/delta T cells. This effect appeared to be cytokine mediated and did not require cell-cell contact. Both recombinant interleukin 2 (rIL-2) and rIL-7 could support the expansion of the gamma/delta T cells, while rIL-7 was only minimally stimulatory for the alpha/beta T cells. The magnitude of the response by gamma/delta T cells to rIL-7 exceeded the response to other in vitro stimuli, including immobilized anti-T cell receptor monoclonal antibody, and was 50-100-fold greater than the alpha/beta T cell response to IL-7. This unique sensitivity of gamma/delta T cells to IL-7 was strongly enhanced by the presence of accessory cells. These cells could be replaced by rIL-1, establishing a synergy for IL-1 and IL-7 as factors that could uniquely stimulate this gamma/delta T cell population. Isolated peritoneal gamma/delta T cells from Listeria-immune mice react to heat-killed Listeria preparations in the presence of macrophages accessory cells in a non-H-2-restricted manner. Considered collectively, these results suggest a potential mechanism by which gamma/delta T cells can predominate in epithelial tissues and at sites of infection.


1996 ◽  
Vol 183 (3) ◽  
pp. 1193-1203 ◽  
Author(s):  
T G Diacovo ◽  
S J Roth ◽  
C T Morita ◽  
J P Rosat ◽  
M B Brenner ◽  
...  

We have compared the ability of human alpha/beta and gamma/delta T lymphocytes to adhere to selectin-bearing substrates, an interaction thought to be essential for homing and localization at sites of inflammation. Both T cell populations form rolling adhesions on E- and P-selectin substrates under physiologic flow conditions. Although equivalent to alpha/beta T cells in binding to E-selectin, gamma/delta T cells demonstrated greater ability to adhere to P-selectin that was purified or expressed on the surface of activated, adherent platelets. Under static conditions, 80% of gamma/delta T cells and 53% of alpha/beta T cells formed shear-resistant adhesions to P-selectin, whereas only 30% of gamma/delta and alpha/beta T cells adhered to E-selectin. The enhance ability of gamma/delta T cells to adhere to P-selectin cannot be attributed to differences in expression of the P-selectin glycoprotein ligand (PSGL-1), as all alpha/beta T cells versus approximately 75% of gamma/delta T cells expressed PSGL-1. Both cell populations expressed a similar percentage of the carbohydrate antigens sialyl LewisX and cutaneous lymphocyte-associated antigen. Depletion of lymphocyte populations or T cell clones bearing these oligosaccharides with the monoclonal antibody CSLEX-1 and HECA-452, respectively, resulted in a substantial reduction in adhesion to E-selectin and slight reduction in adhesion to P-selectin under flow conditions. Treatment of cells with an endopeptidase that selectively degrades O-sialomucins such as PSGL-1, abolished P-selectin but not E-selectin adhesion. Removal of terminal sialic acids with neuraminidase or protease treatment of cells abrogated cell adhesion to both selectin substrates. These results provide direct evidence for the presence of distinct E- and P-selectin ligands on T lymphocytes and suggest that gamma/delta T cells may be preferentially recruited to inflammatory sites during the early stages of an immune response when P-selectin is upregulated.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3893-3893
Author(s):  
Francesca Fiore ◽  
Barbara Castella ◽  
Barbara Nuschak ◽  
Raffaello Bertieri ◽  
Sara Mariani ◽  
...  

Abstract Vgamma9/Vdelta2 (gamma/delta) T cells represent the major subset of unconventional T cells circulating in the peripheral blood. Gamma/delta T cells play a major role in immune defenses against microbes, stressed cells and tumor cells. This property is based on their capability to naturally recognize phosphoantigens (pAgs), which are produced via the mevalonate (Mev) or the DOXP pathway in mammalian and nonmammalian cells, and induced self-ligands, which are de novo expressed or upregulated on the surface of stressed or tumor cells. Interestingly, gamma/delta T cells can also be activated by aminobisphosphonates (ABP)-treated monocytes. We have previously shown that ABP specifically target the Mev pathway of monocytes and induce the accumulation of phosphorylated Mev metabolites naturally recognized by gamma/delta T cells. The aim of this work was to determine whether ABP-treated dendritic cells (DC) can also activate gamma/delta T cells and whether this activation, if any, is detrimental or beneficial to the generation of antigen (Ag)-specific MHC-restricted immune responses mediated by conventional alpha/beta T cells. To this end, we have generated highly purified immature (iDC) and mature DC (mDC) from peripheral blood monocytes of healthy donors and incubated with zoledronic acid (Zol) for 24 hours. Zol is the most potent ABP currently available for clinical use. Zol treatment did not affect the phenotype and immunostimulatory properties of iDC and mDC. Zol-treated iDC and mDC induced a rapid and vigorous expansion of central memory and effector memory gamma/delta T cells. Zol-treated iDC were more potent inducers of gamma/delta T-cell activation than mDC and monocytes. Activated gamma/delta T cells displayed antitumor activity and expressed on the cell surface the appropriate antigen repertoire to target secondary lymphoid organs and exert costimulatory activity on conventional alpha/beta T cells. Indeed, an in vitro model showed that antigen-specific MHC-restricted immune responses againt the influenza matrix peptide were significantly improved by the concurrent activation of gamma/delta T cells. This is the first report showing that: 1) DC can simultaneously be primed to activate both gamma/delta and alpha/beta T cells; 2) the former act as cellular adjuvants for the development of adaptive immune responses. In conclusion, large numbers of gamma/delta T cells with effector and costimulatory activities can rapidly be generated by Zol-treated iDC/mDC. This strategy is worth of further investigation to improve adoptive cell therapy and vaccine interventions against tumors and infections.


1994 ◽  
Vol 179 (1) ◽  
pp. 365-369 ◽  
Author(s):  
H Ohno ◽  
S Ono ◽  
N Hirayama ◽  
S Shimada ◽  
T Saito

zeta and eta chains of the T cell antigen receptor (TCR) complex and the gamma chain of Fc receptors (FcR gamma) constitute a family of proteins important for the expression of, and signal transduction through, these receptors in hematopoietic cells. In zeta-deficient mice, TCR expression was reduced in most T cells. By contrast, CD8 alpha alpha + TCR-gamma/delta + intestinal intraepithelial lymphocytes in these mice expressed a normal level of TCR. Biochemical analysis of the TCR complex in these cells from zeta-deficient as well as normal mice revealed the predominant usage of FcR gamma. Furthermore, gamma/delta + T cells in epithelia of the skin and female reproductive organs from zeta-deficient mice also showed relatively high TCR expression, indicating the usage of FcR gamma. These observations demonstrate the preferential usage of FcR gamma by gamma/delta + T cells localized in epithelia of normal mice.


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