scholarly journals Autocrine growth and tumorigenicity of interleukin 2-dependent helper T cells transfected with IL-2 gene.

1989 ◽  
Vol 169 (1) ◽  
pp. 13-25 ◽  
Author(s):  
H Karasuyama ◽  
N Tohyama ◽  
T Tada

We introduced a mouse IL-2 cDNA expression vector into an IL-2-dependent mouse helper T cell line HT-2. Transfected cells secreted substantial amounts of IL-2, to which they themselves responded by proliferating without further requirement for exogenous IL-2. The proliferation was a direct function of the cell density and was inhibitable by antibodies against IL-2 or IL-2-R, indicating the autocrine nature of the proliferation. Those producing higher amounts of IL-2 were found to be tumorigenic when inoculated into nude mice. The latency period of tumor development correlated inversely with the level of IL-2 secreted. Tumor cells proliferated in vitro in an IL-2 autocrine fashion indistinguishable from that of the inoculated cells. We thus provide evidence that the aberrant activation of the IL-2 autocrine circuit can lead T cells to malignant transformation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2606-2606
Author(s):  
Ani ta K Gandhi ◽  
Audrey Rogovitz ◽  
Antonia Lopez-Girona ◽  
Derek Mendy ◽  
Lisa Morrison ◽  
...  

Abstract Introduction: Lenalidomide is approved in the US for the treatment of transfusion-dependent patients with anemia due to Low- or Intermediate-1-risk myelodysplastic syndromes associated with a del (5q) cytogenetic abnormality, with or without additional cytogenetic abnormalities. Lenalidomide is also approved for use in the US and Europe in combination with dexamethasone in previously treated multiple myeloma patients. In vitro and ex vivo studies have shown that lenalidomide has a direct antiproliferative effect against tumor cells and induces antiangiogenesis. It has also been shown to have immunomodulatory activity, including co-stimulatory effects on T and NK cells. Using the yeast 3-hybrid system, based on a leukemia cDNA library and biotinylated lenalidomide analog, we identified 16 putative lenalidomide-binding proteins from 700,000 clones screened. These included CD3-epsilon-associated protein (CAST) and GDP-mannose pyrophosphorylase A (GMPPA). CAST binds to the T cell receptor and is also part of the RNA polymerase 1 complex. GMPPA is a nucleotidyl transferase that converts mannose-1-phosphate and GTP to GDP-mannose, which is involved in the production of N-linked oligosaccharides. To determine whether these proteins are required for lenalidomide-induced immunomodulatory activity, we evaluated the lenalidomide-induced upregulation of interleukin-2 (IL-2) production in primary T cells transfected with siRNA against CAST and GMPPA. Methods: Primary human peripheral blood T cells were transfected with CAST or GMPPA siRNA, or mock siRNA as a control. Reduction of CAST and GMPPA expression was confirmed by qRT-PCR. After 24 hours, transfected cells were stimulated with anti-CD3 mAb in the presence or absence of 0.1 and 1 μM lenalidomide 48 hours. Cells were lysed after 48 hours, and IL-2 mRNA and mature protein levels were quantified using qPCR and ELISA, respectively. Results: CAST gene expression in T cells was reduced by 60% (p<0.05) in CAST siRNA-transfected cells. GMPPA gene expression was reduced by 66% (p<0.05) in GMPPA siRNA-transfected T cells. Lenalidomide-induced IL-2 mRNA production was reduced from 9-fold in controls to 6-fold in CAST siRNA transfectants (p<0.05) and from 15-fold in controls to 6-fold in GMPPA siRNA transfectants (p<0.05). Lenalidomide-induced IL-2 protein production was reduced from 22-fold in controls down to 8-fold in CAST siRNA transfectants (p<0.05) and from 5.6-fold in the controls down to 1.6-fold in GMPPA siRNA transfectants (p<0.05). Conclusion: These findings support the hypothesis that CAST and GMPPA play an important role in the lenalidomide IL-2 induction mechanism in primary T cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katherine E. Harris ◽  
Kyle J. Lorentsen ◽  
Harbani K. Malik-Chaudhry ◽  
Kaitlyn Loughlin ◽  
Harish Medlari Basappa ◽  
...  

AbstractThe use of recombinant interleukin-2 (IL-2) as a therapeutic protein has been limited by significant toxicities despite its demonstrated ability to induce durable tumor-regression in cancer patients. The adverse events and limited efficacy of IL-2 treatment are due to the preferential binding of IL-2 to cells that express the high-affinity, trimeric receptor, IL-2Rαβγ such as endothelial cells and T-regulatory cells, respectively. Here, we describe a novel bispecific heavy-chain only antibody which binds to and activates signaling through the heterodimeric IL-2Rβγ receptor complex that is expressed on resting T-cells and NK cells. By avoiding binding to IL-2Rα, this molecule circumvents the preferential T-reg activation of native IL-2, while maintaining the robust stimulatory effects on T-cells and NK-cells in vitro. In vivo studies in both mice and cynomolgus monkeys confirm the molecule’s in vivo biological activity, extended pharmacodynamics due to the Fc portion of the molecule, and enhanced safety profile. Together, these results demonstrate that the bispecific antibody is a safe and effective IL-2R agonist that harnesses the benefits of the IL-2 signaling pathway as a potential anti-cancer therapy.


2005 ◽  
Vol 95 (2) ◽  
pp. 277 ◽  
Author(s):  
Y.-N. Qian ◽  
W.-J. Jin ◽  
L. Wang ◽  
H.-J. Wang
Keyword(s):  
T Cells ◽  

2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.


Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 494-500
Author(s):  
O Ayanlar-Batuman ◽  
J Shevitz ◽  
UC Traub ◽  
S Murphy ◽  
D Sajewski

Immunoregulatory T and B cell functions in 15 patients with primary myelodysplastic syndrome (MDS) were studied by measuring the proliferative and the stimulatory capacity of T and B cells, respectively, in autologous (auto) and allogeneic (allo) mixed lymphocyte reaction (MLR). T cell proliferation in the auto MLR was 25% of the control (P less than .02), whereas proliferation in the allo MLR was normal. When control T cells were stimulated by MDS B cells, their proliferative response was only 57% of the control (P less than .01). The mechanism responsible for these abnormalities was studied by determining the capacity of MDS and normal T cells to produce interleukin 2 (IL 2) and to generate IL 2 receptors (IL 2R) following stimulation with control and MDS B cells. In the auto MLR of MDS patients, only 3% +/- 2% of T cells developed IL 2R positivity, whereas in control cultures 12% +/- 2% of T cells were positive, as determined by immunofluorescence, using a monoclonal antibody (MoAb) directed against the IL 2R, and FACS analysis. When MDS T cells were stimulated by control B cells, IL 2R generation and the production of IL 2 were within normal limits. In contrast, when control T cells were stimulated by MDS B cells or control B cells, the MDS B cells induced production of only 26% of IL 2 as compared with control B cells. In parallel experiments, IL 2R generation in control T cells stimulated by either MDS or control B cells was similar. We conclude that in the primary MDS, T and B cell interactions are impaired. Although MDS T cells develop normal quantities of IL 2R and produce normal amounts of IL 2 when stimulated by control B cells, they are markedly impaired when stimulated by self B cells. Similarly, MDS B cells can induce IL 2R generation in control T cells but not in MDS T cells. Myelodysplastic B cells are also defective in inducing IL 2 production by normal T cells in an allo MLR. These in vitro abnormalities strongly suggest that generation of lymphocytes with immunoregulatory functions is impaired in patients with MDS.


1973 ◽  
Vol 137 (3) ◽  
pp. 721-739 ◽  
Author(s):  
Michael Hoffmann ◽  
John W. Kappler

The specificity of antigen recognition by thymus-derived helper cells (T cells) and antibody was examined in mice, heterologous erythrocyte antigens from sheep (SRBC), goat (GRBC), burro (BRBC), chicken (CRBC), and toad (TRBC) being used. Antibody specificity was tested by a number of functional assays: hemagglutination, hemolysis, and immune suppression. The specificity of T cells was determined by titrating their ability to help the in vitro antitrinitrophenol (TNP) responses of mouse spleen cultures immunized with the hapten coupled to the various test erythrocytes as carrier. Anti-SRBC antibody cross-reacted with GRBC, but not with BRBC, CRBC, or TRBC. In contrast, SRBC-primed helper T cells cross-reacted with both GRBC and BRBC, but not with CRBC or TRBC, indicating a difference in the specificity of antigen recognition between the cellular and the humoral immune responses.


1981 ◽  
Vol 154 (1) ◽  
pp. 24-34 ◽  
Author(s):  
G G Miller ◽  
P I Nadler ◽  
Y Asano ◽  
R J Hodes ◽  
D H Sachs

Treatment of BALB/c mice with purified pig anti-(BALB/c anti-nuclease) anti-idiotypic antibodies has been found to induce the appearance of idiotype-bearing immunoglobulins (Id') in the serum of these mice in the absence of detectable antigen binding activity. This phenomenon appeared to require T cells in the hosts because no Id' was detected in the serum of nude mice similarly treated. Furthermore, the spleens of BALB/c mice treated with anti-idiotype were found to contain helper T cells capable of providing help in an in vitro plaque-forming cell response to trinitrophenyl-nuclease equivalent to that provided by helper T cells from the spleens of nuclease-primed animals. Helper T cells from both anti-idiotype-treated and nuclease-treated animals were found to be antigen-specific and to be similarly susceptible to elimination by treatment with anti-idiotype plus complement. Therefore, treatment with both antigen and anti-idiotype appeared to prime similar populations of antigen-specific helper T cells, while having different effects on the induction of antibody. These findings are consistent with the network theory of receptor interactions in the immune response, and may provide a means for studying individual cell populations involved in such interactions.


Blood ◽  
2000 ◽  
Vol 95 (9) ◽  
pp. 2760-2769 ◽  
Author(s):  
Claudio Casoli ◽  
Elisa Vicenzi ◽  
Andrea Cimarelli ◽  
Giacomo Magnani ◽  
Paolo Ciancianaini ◽  
...  

The influence of human T-cell leukemia/lymphoma virus type II (HTLV-II) in individuals also infected with HIV-1 is poorly understood. To evaluate the reciprocal influence of HTLV-II and HIV-1 infection, primary peripheral blood mononuclear cell (PBMC) cultures from coinfected individuals were established in the presence of interleukin 2 (IL-2). In these cultures, the kinetics of HTLV-II replication always preceded those of HIV-1. Noteworthy, the kinetics of HIV-1 production were inversely correlated to the HTLV-II proviral load in vivo and its replication ex vivo. These observations suggested a potential interaction between the 2 retroviruses. In this regard, the levels of IL-2, IL-6, and tumor necrosis factor- (TNF-) were measured in the same coinfected PBMC cultures. Endogenous IL-2 was not produced, whereas IL-6 and TNF- were secreted at levels compatible with their known ability to up-regulate HIV-1 expression. The HIV-suppressive CC-chemokines RANTES, macrophage inflammatory protein-1 (MIP-1), and MIP-1β were also determined in IL-2–stimulated PBMC cultures. Of interest, their kinetics and concentrations were inversely related to those of HIV-1 replication. Experiments were performed in which CD8+ T cells or PBMCs from HTLV-II monoinfected individuals were cocultivated with CD4+ T cells from HIV-1 monoinfected individuals separated by a semipermeable membrane in the presence or absence of antichemokine neutralizing antibodies. The results indicate that HTLV-II can interfere with the replicative potential of HIV-1 by up-regulating viral suppressive CC-chemokines and, in particular, MIP-1. This study is the first report indicating that HTLV-II can influence HIV replication, at least in vitro, via up-regulation of HIV-suppressive chemokines.


2019 ◽  
Vol 221 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Ana Godinho-Santos ◽  
Russell B Foxall ◽  
Ana V Antão ◽  
Bárbara Tavares ◽  
Tiago Ferreira ◽  
...  

Abstract Follicular helper T cells (Tfh), CD4 lymphocytes critical for efficient antibody responses, have been shown to be key human immunodeficiency virus (HIV)-1 reservoirs. Human immunodeficiency virus-2 infection represents a unique naturally occurring model for investigating Tfh role in HIV/acquired immune deficiency syndrome, given its slow rate of CD4 decline, low to undetectable viremia, and high neutralizing antibody titers throughout the disease course. In this study, we investigated, for the first time, Tfh susceptibility to HIV-2 infection by combining in vitro infection of tonsillar Tfh with the ex vivo study of circulating Tfh from HIV-2-infected patients. We reveal that Tfh support productive HIV-2 infection and are preferential viral targets in HIV-2-infected individuals.


Blood ◽  
2010 ◽  
Vol 115 (23) ◽  
pp. 4750-4757 ◽  
Author(s):  
Pedro J. Cejas ◽  
Matthew C. Walsh ◽  
Erika L. Pearce ◽  
Daehee Han ◽  
Gretchen M. Harms ◽  
...  

Abstract Transforming growth factor-β (TGF-β) has an essential role in the generation of inducible regulatory T (iTreg) and T helper 17 (Th17) cells. However, little is known about the TGF-β–triggered pathways that drive the early differentiation of these cell populations. Here, we report that CD4+ T cells lacking the molecular adaptor tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) exhibit a specific increase in Th17 differentiation in vivo and in vitro. We show that TRAF6 deficiency renders T cells more sensitive to TGF-β–induced Smad2/3 activation and proliferation arrest. Consistent with this, in TRAF6-deficient T cells, TGF-β more effectively down-regulates interleukin-2 (IL-2), a known inhibitor of Th17 differentiation. Remarkably, TRAF6-deficient cells generate normal numbers of Foxp3-expressing cells in iTreg differentiation conditions where exogenous IL-2 is supplied. These findings show an unexpected role for the adaptor molecule TRAF6 in Smad-mediated TGF-β signaling and Th17 differentiation. Importantly, the data also suggest that a main function of TGF-β in early Th17 differentiation may be the inhibition of autocrine and paracrine IL-2–mediated suppression of Th17 cell generation.


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