HIV-1–specific cytotoxicity is preferentially mediated by a subset of CD8+ T cells producing both interferon-γ and tumor necrosis factor–α

Blood ◽  
2004 ◽  
Vol 104 (2) ◽  
pp. 487-494 ◽  
Author(s):  
Mathias Lichterfeld ◽  
Xu G. Yu ◽  
Michael T. Waring ◽  
Stanley K. Mui ◽  
Mary N. Johnston ◽  
...  

Abstract CD8+ T cells play a crucial role in the control of viral infections by direct elimination of infected cells and secretion of a number of soluble factors. Recent data suggest that HIV-1-specific CD8+ T cell subsets may differ in their ability to exert these effector functions. Here, we directly compared the cytokine secretion patterns and cytotoxic capacity of HIV-1-specific CD8+ T cells, using a flow-cytometric cytotoxicity assay based on caspase-3 activation in dying target cells. These experiments revealed considerable intraindividual and interindividual differences among epitope-specific T-cell effector functions: while the frequency of HIV-1-specific CD8+ T cells secreting interferon-γ but no tumor necrosis factor-α (TNF-α) following antigenic stimulation was only weakly correlated to their cytotoxic activity (R = 0.05, P = .57), a subset of CD8+ T cells secreting both inter-feron-γ and TNF-α was substantially more strongly associated with cytotoxicity (R = 0.67, P < .001). This subset of CD8+ T cells also exhibited stronger intracellular perforin expression and more pronounced direct ex vivo HIV-1-specific cytoxicity than CD8+ T cells secreting solely interferon-γ following sorting of these subpopulations according to their cytokine profile. These results suggest that HIV-1-specific cytotoxicity of CD8+ T cells is preferentially mediated by a subset of CD8+ T cells secreting both interferon-γ and TNF-α. (Blood. 2004;104:487-494)

2001 ◽  
Vol 195 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mauritius Menges ◽  
Susanne Rößner ◽  
Constanze Voigtländer ◽  
Heike Schindler ◽  
Nicole A. Kukutsch ◽  
...  

Mature dendritic cells (DCs) are believed to induce T cell immunity, whereas immature DCs induce T cell tolerance. Here we describe that injections of DCs matured with tumor necrosis factor (TNF)-α (TNF/DCs) induce antigen-specific protection from experimental autoimmune encephalomyelitis (EAE) in mice. Maturation by TNF-α induced high levels of major histocompatibility complex class II and costimulatory molecules on DCs, but they remained weak producers of proinflammatory cytokines. One injection of such TNF/DCs pulsed with auto-antigenic peptide ameliorated the disease score of EAE. This could not be observed with immature DCs or DCs matured with lipopolysaccharide (LPS) plus anti-CD40. Three consecutive injections of peptide-pulsed TNF/DCs derived from wild-type led to the induction of peptide-specific predominantly interleukin (IL)-10–producing CD4+ T cells and complete protection from EAE. Blocking of IL-10 in vivo could only partially restore the susceptibility to EAE, suggesting an important but not exclusive role of IL-10 for EAE prevention. Notably, the protection was peptide specific, as TNF/DCs pulsed with unrelated peptide could not prevent EAE. In conclusion, this study describes that stimulation by TNF-α results in incompletely matured DCs (semi-mature DCs) which induce peptide-specific IL-10–producing T cells in vivo and prevent EAE.


2012 ◽  
Vol 39 (5) ◽  
pp. 979-985 ◽  
Author(s):  
ALESSANDRO ANTONELLI ◽  
POUPAK FALLAHI ◽  
SILVIA MARTINA FERRARI ◽  
DILIA GIUGGIOLI ◽  
MICHELE COLACI ◽  
...  

Objective.We evaluated the effect of interferon-γ (IFN-γ) and/or tumor necrosis factor-α (TNF-α) on the secretion of prototype proinflammatory cytokine interleukin 6 (IL-6), compared to T-helper 1 [Th1; chemokine (C-X-C motif) ligand 10 (CXCL10)] or Th2 [chemokine (C-C motif) ligand 2 (CCL2)] chemokines, in primary cultured fibroblasts from patients with systemic sclerosis (SSc) at an early stage of the disease.Methods.Fibroblast cultures from 5 SSc patients (disease duration < 2 yrs) and 5 healthy controls were evaluated for the production of IL-6, CXCL10, and CCL2 at the basal level and after stimulation with IFN-γ and/or TNF-α.Results.SSc fibroblasts basally produced higher levels of IL-6 than controls, while no difference was observed about CCL2 and CXCL10. TNF-α was able to dose-dependently induce IL-6 and CCL2 secretion in SSc, but not in control fibroblasts. By stimulation with increasing doses of IFN-γ, SSc fibroblasts were induced to secrete CCL2 and CXCL10, while no effect was observed on IL-6. The combination of IFN-γ and TNF-α induced a strong secretion of IL-6 and CCL2 in SSc fibroblasts but not in controls. In contrast, the synergistic effect of IFN-γ and TNF-α on CXCL10 secretion was similar in SSc fibroblasts and in controls.Conclusion.SSc fibroblasts participate in the self-perpetuation of inflammation by releasing IL-6, CXCL10, and CCL2 under the influence of IFN-γ and/or TNF-α. SSc fibroblasts are more active than controls in the secretion of IL-6 at baseline, and in the production of IL-6 and CCL2 under the combined IFN-γ/TNF-α stimulation.


Blood ◽  
2001 ◽  
Vol 97 (8) ◽  
pp. 2381-2389 ◽  
Author(s):  
Nevila Hyka ◽  
Jean-Michel Dayer ◽  
Christine Modoux ◽  
Tadahiko Kohno ◽  
Carl K. Edwards ◽  
...  

Abstract Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), essential components in the pathogenesis of immunoinflammatory diseases, are strongly induced in monocytes by direct contact with stimulated T lymphocytes. This study demonstrates that adult human serum (HS) but not fetal calf or cord blood serum displays inhibitory activity toward the contact-mediated activation of monocytes by stimulated T cells, decreasing the production of both TNF-α and IL-1β. Fractionation of HS and N-terminal microsequencing as well as electroelution of material subjected to preparative electrophoresis revealed that apolipoprotein A-I (apo A-I), a “negative” acute-phase protein, was the inhibitory factor. Functional assays and flow cytometry analyses show that high-density lipoprotein (HDL)-associated apo A-I inhibits contact-mediated activation of monocytes by binding to stimulated T cells, thus inhibiting TNF-α and IL-1β production at both protein and messenger RNA levels. Furthermore, apo A-I inhibits monocyte inflammatory functions in peripheral blood mononuclear cells activated by either specific antigens or lectins without affecting cell proliferation. These results demonstrate a new anti-inflammatory activity of HDL-associated apo A-I that might have modulating functions in nonseptic conditions. Therefore, because HDL has been shown to bind and neutralize lipopolysaccharide, HDL appears to play an important part in modulating both acute and chronic inflammation. The novel anti-inflammatory function of apo A-I reported here might lead to new therapeutic approaches in inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, and atherosclerosis.


Blood ◽  
2010 ◽  
Vol 116 (16) ◽  
pp. 3089-3098 ◽  
Author(s):  
Roxane Lemoine ◽  
Florence Velge-Roussel ◽  
Florence Herr ◽  
Romain Felix ◽  
Hubert Nivet ◽  
...  

Abstract The high frequency of allogeneic reactive CD8+ T cells in human and their resistance to immunosuppression might be one of the reasons why successful tolerance-inducing strategies in rodents have failed in primates. Studies on the requirement for T-helper cells in priming CD8+ T-cell responses have led to disparate findings. Recent studies have reported CD8+-mediated allograft rejection independently of T-helper cells; however, the mechanisms that govern the activation of these T cells are far from being elucidated. In this study, we demonstrated that lipopolysaccharide-treated dendritic cells (DCs) were able to induce proliferation and cytotoxic activity of allogeneic CD8+ T cells independently of CD4+ T cells, while adding mycophenolic acid (MPA) to LPS abolished this capacity and resulted in anergic CD8+ T cells that secreted high levels of interleukin-4 (IL-4), IL-5, IL-10, and transforming growth factor-β. Interestingly, we demonstrated that MPA inhibited the LPS-induced synthesis of tumor necrosis factor-α, IL-12, and interferon-γ (IFN-γ) in DCs. Importantly, we found that adding exogenous IFN-γ to MPA restored both the synthesis of cytokines and the ability to activate CD8+ T cells. However, adding IL-12 or tumor necrosis factor-α had no effect. These results suggest that IFN-γ has an important role in licensing DCs to prime CD4-independent CD8 allogeneic T cells via an autocrine loop.


Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2670-2679
Author(s):  
Kjetil Hestdal ◽  
Pål Aukrust ◽  
Fredrik Müller ◽  
Egil Lien ◽  
Vigdis Bjerkeli ◽  
...  

The correlation of persistent tumor necrosis factor-α (TNF-α) activation with disease progression in patients infected with human immunodeficiency virus type 1 (HIV-1), suggests a role for TNF-α in the pathogenesis of HIV-1 infection. In the present study, we examined by flow cytometry the expression of membrane-bound (m) components of the TNF system in 33 HIV-1–infected patients and 12 healthy controls. While peripheral blood mononuclear cells (PBMC) from asymptomatic and symptomatic non-acquired immune deficiency syndrome (AIDS) patients showed a significantly increased percentage of mTNF-α+ and mTNF receptor (TNFR)+ cells compared with controls, this was not found in the AIDS group. Compared with healthy controls, AIDS patients had a significantly decreased percentage of both monocytes and lymphocytes expressing p75-TNFR. PBMC from AIDS patients showed a higher p75-TNFR mRNA level and a higher spontaneous release of soluble p75-TNFR than healthy individuals, suggesting enhanced cell surface turnover of this TNFR. The low expression of TNFRs on both lymphocytes and monocytes in the AIDS group was associated with high numbers of HIV-1 RNA copies in plasma, low numbers of CD4+ lymphocytes, and high serum levels of soluble TNFRs. AIDS patients had a decreased percentage of CD8+ lymphocytes expressing TNFRs compared with healthy controls. In contrast, these patients, as well as symptomatic non-AIDS patients, had an increased percentage of TNF-α+ and TNFRs+ cells among remaining CD4+ lymphocytes. The pattern of abnormalities seen in AIDS patients suggests a role for persistent activation of the TNF system in the accelerated CD4+ lymphocyte destruction, the enhanced HIV-1 replication, and the markedly impaired antimicrobial defense in advanced HIV-1-related disease.


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