scholarly journals Combined Treatment with Interleukin-12 and Indomethacin Promotes Increased Resistance in BALB/c Mice with Established Leishmania major Infections

2002 ◽  
Vol 70 (10) ◽  
pp. 5715-5720 ◽  
Author(s):  
Jian Li ◽  
Udaikumar M. Padigel ◽  
Phillip Scott ◽  
Jay P. Farrell

ABSTRACT Following infection of susceptible BALB/c mice with Leishmania major, early production of interleukin-4 (IL-4) is associated with the development of a nonprotective Th2 response and the development of progressive disease. Treatment of mice with IL-12 at the time of infection can promote the activation of a protective Th1 response; however, IL-12 treatment of mice with established infections has little effect on the progress of lesion development. This may be due to a down-regulation of the IL-12 receptor β2 chain (IL-12Rβ2) that accompanies the expansion of IL-4-producing Th2 cells. We have examined whether prostaglandins function to regulate in vivo responsiveness to IL-12. Mice treated with indomethacin are responsive to treatment with exogenous IL-12 through at least the first 2 weeks of infection and, unlike control mice treated with IL-12, develop an enhanced Th1-type response associated with increased enhanced resistance to infection. Cells from indomethacin-treated mice also exhibit enhanced production of gamma interferon (IFN-γ) following in vitro stimulation with IL-12. Although in vivo indomethacin treatment did not appear to influence IL-12 production in infected mice, cells from indomethacin-treated mice did express higher levels of IL-12Rβ2, suggesting that prostaglandins may play a role in the loss of IL-12 responsiveness observed during nonhealing L. major infections.

1994 ◽  
Vol 179 (4) ◽  
pp. 1273-1283 ◽  
Author(s):  
R Manetti ◽  
F Gerosa ◽  
M G Giudizi ◽  
R Biagiotti ◽  
P Parronchi ◽  
...  

Interleukin 12 (IL-12) facilitates the generation of a T helper type 1 (Th1) response, with high interferon gamma (IFN-gamma) production, while inhibiting the generation of IL-4-producing Th2 cells in polyclonal cultures of both human and murine T cells and in vivo in the mouse. In this study, we analyzed the effect of IL-12, present during cloning of human T cells, on the cytokine profile of the clones. The culture system used allows growth of clones from virtually every T cell, and thus excludes the possibility that selection of precommitted Th cell precursors plays a role in determining characteristics of the clones. IL-12 present during the cloning procedures endowed both CD4+ and CD8+ clones with the ability to produce IFN-gamma at levels severalfold higher than those observed in clones generated in the absence of IL-12. This priming was stable because the high levels of IFN-gamma production were maintained when the clones were cultured in the absence of IL-12 for 11 d. The CD4+ and some of the CD8+ clones produced variable amounts of IL-4. Unlike IFN-gamma, IL-4 production was not significantly different in clones generated in the presence or absence of IL-12. These data suggest that IL-12 primes the clone progenitors, inducing their differentiation to high IFN-gamma-producing clones. The suppression of IL-4-producing cells observed in polyclonally generated T cells in vivo and in vitro in the presence of IL-12 is not observed in this clonal model, suggesting that the suppression depends more on positive selection of non-IL-4-producing cells than on differentiation of individual clones. However, antigen-specific established Th2 clones that were unable to produce IFN-gamma with any other inducer did produce IFN-gamma at low but significant levels when stimulated with IL-12 in combination with specific antigen or insoluble anti-CD3 antibodies. This induction of IFN-gamma gene expression was transient, because culture of the established clones with IL-12 for up to 1 wk did not convert them into IFN-gamma producers when stimulated in the absence of IL-12. These results suggest that Th clones respond to IL-12 treatment either with a stable priming for IFN-gamma production or with only a transient low level expression of the IFN-gamma gene, depending on their stage of differentiation.


Parasitology ◽  
2016 ◽  
Vol 143 (12) ◽  
pp. 1615-1621 ◽  
Author(s):  
RABIAA M. SGHAIER ◽  
IMEN AISSA ◽  
HANÈNE ATTIA ◽  
AYMEN BALI ◽  
PABLO A. LEON MARTINEZ ◽  
...  

SUMMARYSynthesized lipophilic tyrosyl ester derivatives with increasing lipophilicity were effective against Leishmania (L.) major and Leishmania infantum species in vitro. These findings prompted us to test in vivo leishmanicidal properties of these molecules and their potential effect on the modulation of immune responses. The experimental BALB/c model of cutaneous leishmaniasis was used in this study. Mice were infected with L. major parasites and treated with three in vitro active tyrosyl esters derivatives.Among these tested tyrosylcaprate (TyC) compounds, only TyC10 exhibited an in vivo anti-leishmanial activity, when injected sub-cutaneously (s.c.). TyC10 treatment of L. major-infected BALB/c mice resulted in a decrease of lesion development and parasite load. TyC10 s.c. treatment of non-infected mice induced an imbalance in interferon γ/interleukin 4 (IFN-γ/IL-4) ratio cytokines towards a Th1 response. Our results indicate that TyC10 s.c. treatment improves lesions’ healing and parasite clearance and may act on the cytokine balance towards a Th1 protective response by decreasing IL-4 and increasing IFN-γ transcripts. TyC10 is worthy of further investigation to uncover its mechanism of action that could lead to consider this molecule as a potential drug candidate.


1994 ◽  
Vol 179 (2) ◽  
pp. 447-456 ◽  
Author(s):  
S L Reiner ◽  
S Zheng ◽  
Z E Wang ◽  
L Stowring ◽  
R M Locksley

Leishmania major are intramacrophage parasites whose eradication requires the induction of T helper 1 (Th1) effector cells capable of activating macrophages to a microbicidal state. Interleukin 12 (IL-12) has been recently identified as a macrophage-derived cytokine capable of mediating Th1 effector cell development, and of markedly enhancing interferon gamma (IFN-gamma) production by T cells and natural killer cells. Infection of macrophages in vitro by promastigotes of L. major caused no induction of IL-12 p40 transcripts, whereas stimulation using heat-killed Listeria or bacterial lipopolysaccharide induced readily detectable IL-12 mRNA. Using a competitor construct to quantitate a number of transcripts, a kinetic analysis of cytokine induction during the first few days of infection by L. major was performed. All strains of mice examined, including susceptible BALB/c and resistant C57BL/6, B10.D2, and C3H/HeN, had the appearance of a CD4+ population in the draining lymph nodes that contained transcripts for IL-2, IL-4, and IFN-gamma (and in some cases, IL-10) that peaked 4 d after infection. In resistant mice, the transcripts for IL-2, IL-4, and IL-10 were subsequently downregulated, whereas in susceptible BALB/c mice, these transcripts were only slightly decreased, and IL-4 continued to be reexpressed at high levels. IL-12 transcripts were first detected in vivo by 7 d after infection, consistent with induction by intracellular amastigotes. Challenge of macrophages in vitro confirmed that amastigotes, in contrast to promastigotes, induced IL-12 p40 mRNA. Reexamination of the cytokine mRNA at 4 d revealed expression of IL-13 in all strains analyzed, suggesting that IL-2 and IL-13 may mediate the IL-12-independent production of IFN-gamma during the first days after infection. Leishmania have evolved to avoid inducing IL-12 from host macrophages during transmission from the insect vector, and cause a striking induction of mRNAs for IL-2, IL-4, IL-10, and IL-13 in CD4+ T cells. Each of these activities may favor survival of the organism.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e21038-e21038 ◽  
Author(s):  
Jesus Vera Aguilera ◽  
Armando Perez-Torres ◽  
Carlos Vera Aguilera ◽  
Matthew Stephen Block ◽  
Narjust Duma ◽  
...  

e21038 Background: Several studies of advanced melanoma patients suggest that combining therapies that target tumor mechanisms of immune evasion with activation of normal immune cell functionality may provide optimal benefits for patients. The synthetic parasite derived GK1 peptide in combination with anti-PD-L1 showed significant longer survival (34 days) compared to GK1 or Anti-PD-L1 alone (23-27 days) in a murine melanoma model (p < 0.05). This means an increase survival increased in 47.82% in the mice treated with GK-1 + anti-PD-L1, 21.7% treated with GK-1, and 6.08% treated with anti-PD-L1. Methods: To elucidate the potential mechanism by which this combination treatment exerts its anti-melanoma effects, C57BL/6 mice were injected with B16-F10-luc2 cells and separated according to treatments in four groups: control, GK-1, anti-PD-L1 and GK-1/anti-PDL-1.Blood samples were collected at day 0, 14, and at euthanization or end of the experiment and monitored for serum cytokines using mice-specific V-PLEX Pro-inflammatory Panel. Results: On day 14, TNF-α levels in the Anti-PD-L1 and GK-1 therapy group was significantly lower compared to control mice. At sacrifice, the combined treatment group demonstrated significant decrease cytokine production in IL-6 and IL-10. Conclusions: The decreased cytokine levels observed in the GK-1/anti-PD-L1 group may explain the significant improved survival. GK-1 is a Th1 response inductor both in vitro and in vivo as it increases IFN-γ, IL-2 but not IL-4 and IL-10. It is noteworthy that when PD-L1 signaling is reduced in T cells these cells proliferate extensively in vitro and produce increased levels of IFN-γ and IL-17, suggesting an enhanced pro-inflammatory phenotype. It has been established that cytokines of Th2 response such as IL-4 and IL-5 and IL-6, have tumor-promoting activity. The anti-melanoma effect of the GK-1/anti-PD-L1 combination observed in the present study could be mediated by decreasing the pro-tumor Th2 response. These results provide novel alternative pathways and potential targets to enhance the clinical effect of the PD-1/PD-L1 blockade pathway.


1990 ◽  
Vol 171 (1) ◽  
pp. 115-127 ◽  
Author(s):  
M D Sadick ◽  
F P Heinzel ◽  
B J Holaday ◽  
R T Pu ◽  
R S Dawkins ◽  
...  

BALB/c mice infected with Leishmania major develop fatal, progressive disease, despite an immune response characterized by expansion of CD4+ T cells in the draining lymph nodes. The immune response has been further characterized by a lack of IFN-gamma mRNA, but increased IL-4 mRNA in lymphoid tissues, and striking elevation of serum IgE. Treatment of infected BALB/c mice with rIFN-gamma at doses shown to be beneficial in other protozoan infections was insufficient to ameliorate L. major infection. In contrast, neutralization of IL-4 by six weekly injections of mAb 11B11 led to attenuation of disease in 100% of animals, and complete cure in 85%. Resolution of disease required the presence of T cells, and recovered mice remained resistant to reinfection at 12 wk. This immunity was adoptively transferable and was dependent on both CD4+ and CD8+ cells. Although administration of anti-IL-4 was associated with fourfold increase in IFN-gamma mRNA in lymph node cells draining the lesion, the coadministration of neutralizing R4 6A2 anti-IFN-gamma mAb had no effect on resistance to disease. This was in marked contrast to resolution of disease in both resistant C57BL/6- and GK1.5-pretreated BALB/c mice that was abrogated by in vivo treatment with anti-IFN-gamma. These data suggest a novel mechanism of cellular immunity established by interference with the development of Th2 cells during infection.


2015 ◽  
Vol 60 (2) ◽  
pp. 797-805 ◽  
Author(s):  
Caroline Schad ◽  
Ulrike Baum ◽  
Benjamin Frank ◽  
Uwe Dietzel ◽  
Felix Mattern ◽  
...  

ABSTRACTLeishmaniasis is one of the major neglected tropical diseases of the world. Druggable targets are the parasite cysteine proteases (CPs) of clan CA, family C1 (CAC1). In previous studies, we identified two peptidomimetic compounds, the aziridine-2,3-dicarboxylate compounds 13b and 13e, in a series of inhibitors of the cathepsin L (CL) subfamily of the papain clan CAC1. Both displayed antileishmanial activityin vitrowhile not showing cytotoxicity against host cells. In further investigations, the mode of action was characterized inLeishmania major. It was demonstrated that aziridines 13b and 13e mainly inhibited the parasitic cathepsin B (CB)-like CPC enzyme and, additionally, mammalian CL. Although these compounds induced cell death ofLeishmaniapromastigotes and amastigotesin vitro, the induction of a proleishmanial T helper type 2 (Th2) response caused by host CL inhibition was observedin vivo. Therefore, we describe here the synthesis of a new library of more selective peptidomimetic aziridine-2,3-dicarboxylates discriminating between host and parasite CPs. The new compounds are based on 13b and 13e as lead structures. One of the most promising compounds of this series is compound s9, showing selective inhibition of the parasite CPsLmaCatB (a CB-like enzyme ofL. major; also namedL. majorCPC) andLmCPB2.8 (a CL-like enzyme ofLeishmania mexicana) while not affecting mammalian CL and CB. It displayed excellent leishmanicidal activities againstL. majorpromastigotes (50% inhibitory concentration [IC50] = 37.4 μM) and amastigotes (IC50= 2.3 μM). In summary, we demonstrate a new selective aziridine-2,3-dicarboxylate, compound s9, which might be a good candidate for futurein vivostudies.


2000 ◽  
Vol 191 (4) ◽  
pp. 683-694 ◽  
Author(s):  
Gilles Foucras ◽  
Laurent Gapin ◽  
Christiane Coureau ◽  
Jean M. Kanellopoulos ◽  
Jean-Charles Guéry

The precursor origin of T helper (Th) cell subsets in vivo has been difficult to study and remains poorly investigated. We have previously shown that chronic administration of soluble protein antigen induces selective development of antigen-specific CD4 Th2 cells in genetically predisposed mouse strains. To analyze the origin of effector T cells in this model, we designed a competitive polymerase chain reaction–based approach to track public BV-J rearrangement expressed by CD4 T cells specific for hen egg white lysozyme (HEL) in BALB/c mice. We show that public T cell clones are predominantly associated with type 1 or 2 effector Th cells recovered after primary immunization in complete or incomplete Freund's adjuvant, respectively. Conversely, continuous administration of soluble antigen, which induces strong memory Th2 response, is associated with a dose-dependent reduction of public clone size by a mechanism resembling clonal anergy. Thus, soluble HEL–induced Th2 cells do not express the public complementarity determining region 3 motifs characteristic of immunogenic challenge in the presence of adjuvant. These results demonstrate that there are multiple pathways of induction of Th2 responses depending on the condition of antigen exposure in vivo, i.e., clonal immune deviation versus recruitment of a different pool of precursor cells.


2009 ◽  
Vol 54 (2) ◽  
pp. 652-659 ◽  
Author(s):  
Klaus Griewank ◽  
Caroline Gazeau ◽  
Andreas Eichhorn ◽  
Esther von Stebut

ABSTRACT As a treatment for leishmaniasis, miltefosine exerts direct toxic effects on the parasites. Miltefosine also modulates immune cells such as macrophages, leading to parasite elimination via oxidative radicals. Dendritic cells (DC) are critical for initiation of protective immunity against Leishmania through induction of Th1 immunity via interleukin 12 (IL-12). Here, we investigated the effects of miltefosine on DC in Leishmania major infections. When cocultured with miltefosine for 4 days, the majority of in vitro-infected DC were free of parasites. Miltefosine treatment did not influence DC maturation (upregulation of major histocompatibility complex II [MHC II] or costimulatory molecules, e.g., CD40, CD54, and CD86) or significantly alter cytokine release (IL-12, tumor necrosis factor alpha [TNF-α], or IL-10). Further, miltefosine DC treatment did not alter antigen presentation, since unrestricted antigen-specific proliferation of CD4+ and CD8+ T cells was observed upon stimulation with miltefosine-treated, infected DC. In addition, miltefosine application in vivo did not lead to maturation/emigration of skin DC. DC NO− production, a mechanism used by phagocytes to rid themselves of intracellular parasites, was also unaltered upon miltefosine treatment. Our data confirm prior studies indicating that in contrast to, e.g., pentavalent antimonials, miltefosine functions independently of the immune system, mostly through direct toxicity against the Leishmania parasite.


2006 ◽  
Vol 26 (17) ◽  
pp. 6403-6411 ◽  
Author(s):  
Woong-Kyung Suh ◽  
Seng Wang ◽  
Gordon S. Duncan ◽  
Yoshiyuki Miyazaki ◽  
Elizabeth Cates ◽  
...  

ABSTRACT Members of the B7 family of cosignaling molecules regulate T-cell proliferation and effector functions by engaging cognate receptors on T cells. In vitro and in vivo blockade experiments indicated that B7-H4 (also known as B7S1 or B7x) inhibits proliferation, cytokine production, and cytotoxicity of T cells. B7-H4 binds to an unknown receptor(s) that is expressed on activated T cells. However, whether B7-H4 plays nonredundant immune regulatory roles in vivo has not been tested. We generated B7-H4-deficient mice to investigate the roles of B7-H4 during various immune reactions. Consistent with its inhibitory function in vitro, B7-H4-deficient mice mounted mildly augmented T-helper 1 (Th1) responses and displayed slightly lowered parasite burdens upon Leishmania major infection compared to the wild-type mice. However, the lack of B7-H4 did not affect hypersensitive inflammatory responses in the airway or skin that are induced by either Th1 or Th2 cells. Likewise, B7-H4-deficient mice developed normal cytotoxic T-lymphocyte reactions against viral infection. Thus, B7-H4 plays a negative regulatory role in vivo but the impact of B7-H4 deficiency is minimal. These results suggest that B7-H4 is one of multiple negative cosignaling molecules that collectively provide a fine-tuning mechanism for T-cell-mediated immune responses.


1994 ◽  
Vol 179 (3) ◽  
pp. 1065-1070 ◽  
Author(s):  
H Quill ◽  
A Bhandoola ◽  
G Trinchieri ◽  
J Haluskey ◽  
D Peritt

The cytokine, interleukin 12 (IL-12), stimulates both natural killer cells and T cells to proliferate and to secrete interferon gamma (IFN-gamma). The T cell proliferative response to IL-12 must be induced and is evident after T cell receptor-mediated stimulation. As reported here, tolerant CD4+ T cells and clones, that are anergic for IL-2 production, are also anergic for induction of the proliferative response to IL-12. Murine T helper 1 clones tolerized in vitro, as well as anergic CD4+ T cells isolated from mice tolerized to the Mls-1a antigen (Ag) in vivo, demonstrated defective induction of proliferation to IL-12 upon restimulation with Ag. IL-12-enhanced production of IFN-gamma was observed in both control and anergic cells after Ag/antigen-presenting cell (APC) activation, although total IFN-gamma secretion by anergic cells was less than that produced by control cells, even in the presence of IL-12. These data indicate that T cell clonal anergy results in profound inhibition of proliferative responses, since the autocrine growth factor, IL-2, is not produced, and the APC-derived cytokine, IL-12, is not an effective stimulus for anergic T cell proliferation.


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