scholarly journals Membrane Tumor Necrosis Factor (TNF) Induced Cooperative Signaling of TNFR60 and TNFR80 Favors Induction of Cell Death Rather Than Virus Production in HIV-infected T Cells

1997 ◽  
Vol 185 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Janis K. Lazdins ◽  
Matthias Grell ◽  
Maja R. Walker ◽  
Kathie Woods-Cook ◽  
Peter Scheurich ◽  
...  

Tumor necrosis factor (TNF) and lymphotoxin (LT) are highly pleiotropic cytokines that play a central role in regulating HIV-1 replication. These cytokines express their activities through two membrane receptors, TNFR60 (p55-60) and TNFR80 (p75-80). In the present study we have demonstrated by means of antagonistic and agonistic receptor-specific antibodies that in latently infected lymphocytic (ACH-2) cells the TNFR60 plays a dominant role in signaling HIV production, although selective activation of TNFR80 by receptor-specific antibodies can also induce HIV production. Unexpectedly, when both TNFRs were activated simultaneously by agonistic antibodies or coculture with cells expressing a noncleavable membrane form of TNF, HIV production was downregulated and induction of cell death was enhanced in ACH-2 cells. More relevant, in vitro HIV-infected peripheral blood lymphocytes cocultured with cells expressing membrane TNF underwent rapid induction of apoptosis with a subsequent reduced HIV production of these lymphocytes cultures. This was not observed with HIV-infected lymphocytes treated with soluble TNF. These data provide evidence for the differential trigger potential of membrane versus soluble TNF and show that TNFR80 is an important modulator of TNF responsiveness of HIV-infected T cells via cooperative signaling with TNFR60.

2002 ◽  
Vol 196 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Nicole Cusson ◽  
Sarah Oikemus ◽  
Elizabeth D. Kilpatrick ◽  
Leslie Cunningham ◽  
Michelle Kelliher

Fas and the tumor necrosis factor receptor (TNFR)1 regulate the programmed cell death of lymphocytes. The death domain kinase, receptor interacting protein (rip), is recruited to the TNFR1 upon receptor activation. In vitro, rip−/− fibroblasts are sensitive to TNF-induced cell death due to an impaired nuclear factor κB response. Because rip−/− mice die at birth, we were unable to examine the effects of a targeted rip mutation on lymphocyte survival. To address the contribution of RIP to immune homeostasis, we examined lethally irradiated mice reconstituted with rip−/− hematopoietic precursors. We observed a decrease in rip−/− thymocytes and T cells in both wild-type C57BL/6 and recombination activating gene 1−/− irradiated hosts. In contrast, the B cell and myeloid lineages are unaffected by the absence of rip. Thus, the death domain kinase rip is required for T cell development. Unlike Fas-associated death domain, rip does not regulate T cell proliferation, as rip−/− T cells respond to polyclonal activators. However, rip-deficient mice contain few viable CD4+ and CD8+ thymocytes, and rip−/− thymocytes are sensitive to TNF-induced cell death. Surprisingly, the rip-associated thymocyte apoptosis was not rescued by the absence of TNFR1, but appears to be rescued by an absence of TNFR2. Taken together, this study implicates RIP and TNFR2 in thymocyte survival.


2003 ◽  
Vol 77 (12) ◽  
pp. 6700-6708 ◽  
Author(s):  
Yida Yang ◽  
Ilia Tikhonov ◽  
Tracy J. Ruckwardt ◽  
Mahmoud Djavani ◽  
Juan Carlos Zapata ◽  
...  

ABSTRACT The human immunodeficiency virus (HIV) Tat protein has a critical role in viral transcription, but this study focuses on its additional role as an extracellular effector of lymphocyte cell death. It is well known that Tat induces tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in peripheral blood mononuclear cells (PBMC), and we show that the majority of TRAIL is produced by the monocyte subset of PBMC. Human monocytes and U937 monoblastoid cells did not take up soluble HIV Tat-86, as T cells did, yet produced more TRAIL than did T cells. TRAIL secretion was induced by Tat and by a cysteine-rich peptide of Tat but not by sulfhydryl-modified Tat toxoid. Although there was only a slight increase in cell surface expression of TRAIL on monocytes, sufficient TRAIL was secreted to be toxic for T cells. The cytotoxicity of Tat-stimulated monocyte medium could be blocked by a TRAIL-neutralizing antibody. T cells treated with Tat did not secrete enough TRAIL to mediate cell death in our assay. Remarkably, uninfected T cells are more susceptible to TRAIL than are HIV-infected T cells. The production of TRAIL by Tat-stimulated monocytes provides a mechanism by which HIV infection can destroy uninfected bystander cells.


1997 ◽  
Vol 186 (12) ◽  
pp. 2075-2080 ◽  
Author(s):  
Brian R. Wong ◽  
Régis Josien ◽  
Soo Young Lee ◽  
Birthe Sauter ◽  
Hong-Li Li ◽  
...  

TRANCE (tumor necrosis factor [TNF]–related activation-induced cytokine) is a new member of the TNF family that is induced upon T cell receptor engagement and activates c-Jun N-terminal kinase (JNK) after interaction with its putative receptor (TRANCE-R). In addition, TRANCE expression is restricted to lymphoid organs and T cells. Here, we show that high levels of TRANCE-R are detected on mature dendritic cells (DCs) but not on freshly isolated B cells, T cells, or macrophages. Signaling by TRANCE-R appears to be dependent on TNF receptor–associated factor 2 (TRAF2), since JNK induction is impaired in cells from transgenic mice overexpressing a dominant negative TRAF2 protein. TRANCE inhibits apoptosis of mouse bone marrow–derived DCs and human monocyte-derived DCs in vitro. The resulting increase in DC survival is accompanied by a proportional increase in DC-mediated T cell proliferation in a mixed leukocyte reaction. TRANCE upregulates Bcl-xL expression, suggesting a potential mechanism for enhanced DC survival. TRANCE does not induce the proliferation of or increase the survival of T or B cells. Therefore, TRANCE is a new DC-restricted survival factor that mediates T cell–DC communication and may provide a tool to selectively enhance DC activity.


2004 ◽  
Vol 193 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Michael C. Jendro ◽  
Frederik Fingerle ◽  
Tobias Deutsch ◽  
Andrea Liese ◽  
Lars K�hler ◽  
...  

2000 ◽  
Vol 68 (3) ◽  
pp. 1428-1434 ◽  
Author(s):  
Michelle Nashleanas ◽  
Phillip Scott

ABSTRACT The ability to activate macrophages in vitro for nitric oxide production and killing of Leishmania major parasites is dependent on tumor necrosis factor, although L. major-infected mice lacking the TNF receptor p55 (TNFRp55−/− mice) or both the TNFRp55 and TNFRp75 (TNFRp55p75−/− mice) are able to produce NO in vivo and eliminate the parasites. Here we report that activated T cells cocultured with macrophages results in TNFR-independent activation sufficient to control parasites and that both CD40/CD40L and LFA-1 contribute to T-cell-mediated macrophage activation. Thus, anti-CD3-stimulated T cells activated TNFR-deficient macrophages, while T cells from CD40L−/− mice were partially defective in triggering NO production by TNFRp55p75−/− macrophages. Moreover, in the presence of gamma interferon, anti-CD40 monoclonal antibody (MAb) activated TNFR-deficient macrophages. Finally, MAb blockade of LFA-1 completely inhibited macrophage NO production. Our data indicate that T cells can activate macrophages in the absence of TNF, thus providing a mechanism for how TNFR-deficient mice can control intracellular pathogens.


Blood ◽  
1989 ◽  
Vol 73 (5) ◽  
pp. 1242-1246 ◽  
Author(s):  
W Digel ◽  
M Stefanic ◽  
W Schoniger ◽  
C Buck ◽  
A Raghavachar ◽  
...  

Abstract The biologic effects of recombinant tumor necrosis factor-alpha (rTNF- alpha) and the expression of specific TNF membrane receptors on isolated neoplastic B cells from previously untreated patients with chronic lymphocytic leukemia (CLL) were investigated in vitro. Isolated B cells were incubated up to six days with various concentrations of rTNF-alpha (0.1 to 100 ng/mL). B cells from most patients proliferated ranged from two to 104 times that of unstimulated cells from the same patients. An optimal proliferative effect was achieved at 25 ng/mL rTNF- alpha and an incubation time between 96 and 120 hours, whereas a low concentration of rTNF-alpha (1 ng/mL) reduced [3H]TdR incorporation in four cases. Metaphase cells were detected in the rTNF-alpha-stimulated cultures that proliferated in response to rTNF-alpha. B cells from three of ten patients proliferated spontaneously and proliferation was further enhanced in two patients by rTNF-alpha. TNF binding assays gave a value of approximately 390 to 1,400 binding sites/cell for TNF and a dissociation constant (kd) of approximately 60 pmol/L. These data indicate that rTNF-alpha, in contrast to its cytotoxic/cytostatic effects, can also induce proliferation of tumor cells.


2014 ◽  
Vol 21 (4) ◽  
pp. 781-794 ◽  
Author(s):  
Tetje C. van der Sluis ◽  
Suzanne van Duikeren ◽  
Suzanna Huppelschoten ◽  
Ekaterina S. Jordanova ◽  
Elham Beyranvand Nejad ◽  
...  

1994 ◽  
Vol 180 (6) ◽  
pp. 2227-2237 ◽  
Author(s):  
N Karin ◽  
D J Mitchell ◽  
S Brocke ◽  
N Ling ◽  
L Steinman

An immunodominant epitope of myelin basic protein (MBP), VHFFKNIVTPRTP (p87-99), is a major target of T cells in lesions of multiple sclerosis (MS) and in experimental allergic encephalomyelitis (EAE). T cells found in EAE lesions bear the same amino acids in the third complementary determining region of the T cell receptor (TCR) as those found in MS lesions. We analyzed the trimolecular interactions between MBP p87-99, class II major histocompatibility complex (MHC), and TCR, and designed soluble inhibitors for therapy. F, N, I, and V at positions 90, 92, 93, and 94 interact with MHC, whereas K, T, and P at positions 91, 95, and 96 interact with TCR. The peptides, p87-99[95T > A] and p87-99[96P > A] could compete more effectively with p87-99 for binding to MHC and could antagonize the in vitro response to T cells to p87-99 more effectively than p87-99[91K > A]. However, only p87-99[91K > A] prevented and reversed EAE, indicating that the extent of MHC or TCR competition does not predict success in treating EAE. To elucidate the mechanism of inhibition of EAE, draining lymph node cells from rats immunized with the native peptide alone or together with each of the three TCR antagonists were challenged in vitro with p87-99. Administration of p87-99[91K > A], but not p87-99 [95T > A] or p87-99[96P > A], reduced the production of tumor necrosis factor (TNF)- alpha and interferon (IFN) gamma. IFN-gamma and TNF-alpha are two cytokines that are critical in the pathogenesis of EAE and MS.


1999 ◽  
Vol 190 (11) ◽  
pp. 1697-1710 ◽  
Author(s):  
Fabienne Mackay ◽  
Stephen A. Woodcock ◽  
Pornsri Lawton ◽  
Christine Ambrose ◽  
Manfred Baetscher ◽  
...  

The cause of many autoimmune and inflammatory diseases is unresolved, although dysregulated production of tumor necrosis factor (TNF) family members appears to be important in many cases. BAFF, a new member of the TNF family, binds to B cells and costimulates their growth in vitro. Mice transgenic for BAFF have vastly increased numbers of mature B and effector T cells, and develop autoimmune-like manifestations such as the presence of high levels of rheumatoid factors, circulating immune complexes, anti–DNA autoantibodies, and immunoglobulin deposition in the kidneys. This phenotype is reminiscent of certain human autoimmune disorders and suggests that dysregulation of BAFF expression may be a critical element in the chain of events leading to autoimmunity.


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