scholarly journals Mixed Formulation of Conventional and Pegylated Meglumine Antimoniate-Containing Liposomes Reduces Inflammatory Process and Parasite Burden in Leishmania infantum-Infected BALB/c Mice

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Levi Eduardo Soares Reis ◽  
Rory Cristiane Fortes de Brito ◽  
Jamille Mirelle de Oliveira Cardoso ◽  
Fernando Augusto Siqueira Mathias ◽  
Rodrigo Dian Oliveira Aguiar Soares ◽  
...  

ABSTRACT Pentavalent antimonial has been the first choice treatment for visceral leishmaniasis; however, it has several side effects that leads to low adherence to treatment. Liposome-encapsulated meglumine antimoniate (MA) arises as an important strategy for chemotherapy enhancement. We evaluated the immunopathological changes using the mixture of conventional and pegylated liposomes with MA. The mice were infected with Leishmania infantum and a single-dose treatment regimen. Comparison was made with groups treated with saline, empty liposomes, free MA, and a liposomal formulation of MA (Lipo MA). Histopathological analyses demonstrated that animals treated with Lipo MA showed a significant decrease in the inflammatory process and the absence of granulomas. The in vitro stimulation of splenocytes showed a significant increase of gamma interferon (IFN-γ) produced by CD8+ T cells and a decrease in interleukin-10 (IL-10) produced by CD4+ and CD8+ T cells in the Lipo MA. Furthermore, the Lipo MA group showed an increase in the IFN-γ/IL-10 ratio in both CD4+ and CD8+ T cell subsets. According to the parasite load evaluation using quantitative PCR, the Lipo MA group showed no L. infantum DNA in the spleen (0.0%) and 41.4% in the liver. In addition, we detected a low positive correlation between parasitism and histopathology findings (inflammatory process and granuloma formation). Thus, our results confirmed that Lipo MA is a promising antileishmanial formulation able to reduce the inflammatory response and induce a type 1 immune response, accompanied by a significant reduction of the parasite burden into hepatic and splenic compartments in treated animals.

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2428
Author(s):  
Frank Liang ◽  
Azar Rezapour ◽  
Peter Falk ◽  
Eva Angenete ◽  
Ulf Yrlid

TILs comprise functionally distinct conventional and unconventional T cell subsets and their role in responses to CRC treatments is poorly understood. We explored recovery of viable TILs from cryopreserved tumor biopsies of (chemo)-radiated patients with rectal cancer to establish a platform for retrospective TIL analyses of frozen tumors from pre-selected study cohorts. Frequencies of TIL subsets and their capacity to mount IFN-γ responses in cell suspensions of fresh vs. cryopreserved portions of the same tumor biopsies were determined for platform validation. The percentages and proportions of CD4+ TILs and CD8+ cytotoxic T lymphocytes (CTLs) among total TILs were not affected by cryopreservation. While recovery of unconventional γδ T cells and mucosal-associated invariant T cells (MAIT cells) was stable after cryopreservation, the regulatory T cells (Tregs) were reduced, but in sufficient yields for quantification. IFN-γ production by in vitro-stimulated CD4+ TILs, CTLs, γδ T cells, and MAIT cells were proportionally similar in fresh and cryopreserved tumor portions, albeit the latter displayed lower levels. Thus, the proposed platform intended for TIL analyses on cryopreserved tumor biobank biopsies holds promises for studies linking the quantity and quality of TIL subsets with specific clinical outcome after CRC treatment.


2014 ◽  
Vol 82 (9) ◽  
pp. 3704-3712 ◽  
Author(s):  
Maria M. Figueiredo ◽  
Beatriz Deoti ◽  
Izabela F. Amorim ◽  
Aldair J. W. Pinto ◽  
Andrea Moraes ◽  
...  

ABSTRACTUsing flow cytometry, we evaluated the frequencies of CD4+and CD8+T cells and Foxp3+regulatory T cells (Tregs) in mononuclear cells in the jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected withLeishmania infantumand in uninfected controls. All infected dogs showed chronic lymphadenitis and enteritis. Despite persistent parasite loads, no erosion or ulcers were evident in the epithelial mucosa. The colon harbored more parasites than the jejunum. Frequencies of total CD4+, total Foxp3, and CD4+Foxp3+cells were higher in the jejunum than in the colon. Despite negative enzyme-linked immunosorbent assay (ELISA) serum results for cytokines, levels of interleukin-10 (IL-10), gamma interferon (IFN-γ), transforming growth factor beta (TGF-β), and tumor necrosis factor alpha (TNF-α) were higher in the jejunum than in the colon for infected dogs. However, IL-4 levels were higher in the colon than in the jejunum for infected dogs. There was no observed correlation between clinical signs and histopathological changes or immunological and parasitological findings in the gastrointestinal tract (GIT) of canines with visceral leishmaniasis. However, distinct segments of the GIT presented different immunological and parasitological responses. The jejunum showed a lower parasite load, with increased frequencies and expression of CD4, Foxp3, and CD8 receptors and IL-10, TGF-β, IFN-γ, and TNF-α cytokines. The colon showed a higher parasite load, with increasing expression of IL-4.Leishmania infantuminfection increased expression of CD4, Foxp3, IL-10, TGF-β, IFN-γ, and TNF-α and reduced CD8 and IL-4 expression in both the jejunum and the colon.


Blood ◽  
2009 ◽  
Vol 113 (4) ◽  
pp. 837-845 ◽  
Author(s):  
Guangming Gong ◽  
Lingyun Shao ◽  
Yunqi Wang ◽  
Crystal Y. Chen ◽  
Dan Huang ◽  
...  

Abstract Although Foxp3+ T regulatory cells (Tregs) are well documented for their ability to suppress various immune cells, T-cell subsets capable of counteracting Tregs have not been demonstrated. Here, we assessed phosphoantigen-activated Vγ2Vδ2 T cells for the ability to interplay with Tregs in the context of mycobacterial infection. A short-term IL-2 treatment regimen induced marked expansion of CD4+CD25+Foxp3+ T cells and subsequent suppression of mycobacterium-driven increases in numbers of Vγ2Vδ2 T cells. Surprisingly, activation of Vγ2Vδ2 T cells by adding phosphoantigen Picostim to the IL-2 treatment regimen down-regulated IL-2–induced expansion of CD4+CD25+Foxp3+ T cells. Consistently, in vitro activation of Vγ2Vδ2 T cells by phosphoantigen plus IL-2 down-regulated IL-2–induced expansion of CD4+CD25+Foxp3+ T cells. Interestingly, anti–IFN-γ–neutralizing antibody, not anti–TGF-β or anti–IL-4, reduced the ability of activated Vγ2Vδ2 T cells to down-regulate Tregs, suggesting that autocrine IFN-γ and its network contributed to Vγ2Vδ2 T cells' antagonizing effects. Furthermore, activation of Vγ2Vδ2 T cells by Picostim plus IL-2 treatment appeared to reverse Treg-driven suppression of immune responses of phosphoantigen-specific IFNγ+ or perforin+ Vγ2Vδ2 T cells and PPD-specific IFNγ+αβ T cells. Thus, phos-phoantigen activation of Vγ2Vδ2 T cells antagonizes IL-2–induced expansion of Tregs and subsequent suppression of Ag-specific antimicrobial T-cell responses in mycobacterial infection.


2015 ◽  
Vol 83 (5) ◽  
pp. 2118-2126 ◽  
Author(s):  
Truc Hoang ◽  
Else Marie Agger ◽  
Joseph P. Cassidy ◽  
Jan P. Christensen ◽  
Peter Andersen

Protein energy malnutrition (PEM) increases susceptibility to infectious diseases, including tuberculosis (TB), but it is not clear how PEM influences vaccine-promoted immunity to TB. We demonstrate that PEM during low-level steady-state TB infection in a mouse model results in rapid relapse ofMycobacterium tuberculosis, as well as increased pathology, in bothMycobacterium bovisBCG-vaccinated and unvaccinated animals. PEM did not change the overall numbers of CD4 T cells in BCG-vaccinated animals but resulted in an almost complete loss of antigen-specific cytokine production. Furthermore, there was a change in cytokine expression characterized by a gradual loss of multifunctional antigen-specific CD4 T cells and an increased proportion of effector cells expressing gamma interferon and tumor necrosis factor alpha (IFN-γ+TNF-α+and IFN-γ+cells). PEM duringM. tuberculosisinfection completely blocked the protection afforded by the H56-CAF01 subunit vaccine, and this was associated with a very substantial loss of the interleukin-2-positive memory CD4 T cells promoted by this vaccine. Similarly, PEM during the vaccination phase markedly reduced the H56-CAF01 vaccine response, influencing all cytokine-producing CD4 T cell subsets, with the exception of CD4 T cells positive for TNF-α only. Importantly, this impairment was reversible and resupplementation of protein during infection rescued both the vaccine-promoted T cell response and the protective effect of the vaccine againstM. tuberculosisinfection.


2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Cristiano C. P. dos Santos ◽  
Guilherme S. Ramos ◽  
Renata C. De Paula ◽  
Karen F. Faria ◽  
Paulo O. L. Moreira ◽  
...  

ABSTRACT The treatment of dogs naturally infected with Leishmania infantum using meglumine antimoniate (MA) encapsulated in conventional liposomes (LC) in association with allopurinol has been previously reported to promote a marked reduction in the parasite burden in the main infection sites. Here, a new assay in naturally infected dogs was performed using a novel liposome formulation of MA consisting of a mixture of conventional and long-circulating (PEGylated) liposomes (LCP), with expected broader distribution among affected tissues of the mononuclear phagocyte system. Experimental groups of naturally infected dogs were as follows: LCP plus Allop, receiving LCP intravenously as 2 cycles of 6 doses (6.5 mg Sb/kg of body weight/dose) at 4-day intervals plus allopurinol at 30 mg/kg/12 h per os (p.o.) during 130 days (LCP+Allop); LC plus Allop, receiving LC intravenously as 2 cycles of 6 doses (6.5 mg Sb/kg/dose) plus allopurinol during 130 days (LC+Allop); Allop, treated with allopurinol only; and a nontreated control. Parasite loads were evaluated by quantitative PCR in liver, spleen, and bone marrow tissue and by immunohistochemistry in the ear skin, before treatment, just after treatment, and 4 months later. The LCP+Allop and LC+Allop groups, but not the Allop group, showed significant suppression of the parasites in the liver, spleen, and bone marrow 4 months after treatment compared to the pretreatment period or the control group. Only LCP+Allop group showed significantly lower parasite burden in the skin in comparison to the control group. On the basis of clinical staging and parasitological evaluations, the LCP formulation exhibited a more favorable therapeutic profile than the LC one, being therefore promising for the treatment of canine visceral leishmaniasis.


2001 ◽  
Vol 75 (5) ◽  
pp. 2107-2118 ◽  
Author(s):  
Ting Liu ◽  
Thomas J. Chambers

ABSTRACT Viral encephalitis caused by neuroadapted yellow fever 17D virus (PYF) was studied in parental and gamma interferon (IFN-γ)-deficient (IFN-γ knockout [GKO]) C57BL/6 mice. The T-cell responses which enter the brain during acute fatal encephalitis of nonimmunized mice, as well as nonfatal encephalitis of immunized mice, were characterized for relative proportions of CD4+ and CD8+cells, their proliferative responses, and antigen-specific expression of cytokines during stimulation in vitro. Unimmunized mice accumulated only low levels of T cells within the brain during fatal disease, whereas the brains of immunized mice contained higher levels of both T-cell subsets in response to challenge, with CD8+ cells increased relative to the CD4+ subset. The presence of T cells correlated with the time at which virus was cleared from the central nervous system in both parental and GKO mice. Lymphocytes isolated from the brains of challenged immunized mice failed to proliferate in vitro in response to T-cell mitogens or viral antigens; however, IFN-γ, interleukin 4 (IL-4), and, to a lesser extent, IL-2 were detectable after stimulation. The levels of IFN-γ, but not IL-2 or IL-4, were augmented in response to viral antigen, and this specificity was detectable in the CD4+ compartment. When tested for the ability to survive both immunization and challenge with PYF virus, GKO and CD8 knockout mice did not differ from parental mice (80 to 85% survival), although GKO mice exhibited a defect in virus clearance. In contrast, CD4 knockout and Igh-6 mice were unable to resist challenge. The data implicate antibody in conjunction with CD4+ lymphocytes bearing a Th1 phenotype as the critical factors involved in virus clearance in this model.


2021 ◽  
Vol 11 ◽  
Author(s):  
Philipp Adams ◽  
Gilles Iserentant ◽  
Jean-Yves Servais ◽  
Linos Vandekerckhove ◽  
Guido Vanham ◽  
...  

Antiretroviral therapy (ART) is not curative as HIV-1 persists in long-lived viral reservoirs. Consequently, patients are dependent on life-long drug adherence with possible side effects. To overcome these limitations strategies of a functional cure aim at ART free viral remission. In this study, we sought to identify detailed subsets of anti-viral CD8+ T cell immunity linked to natural long-term control of HIV-1 infection. Here, we analyzed HIV controllers and ART suppressed progressors for in vitro viral suppressive capacity (VSC) at baseline and after peptide stimulation. Functional properties and phenotypes of CD8+ T cells were assessed by IFN-γ ELISPOT and 18 color flow cytometry. HIV controllers showed significantly increased suppression at baseline as well as after peptide stimulation. IFN-γ secretion and the proliferation marker Ki67 positively correlated with VSC. Moreover, the detailed phenotype of three distinct multifunctional memory CD8+ T cell subsets were specific traits of HIV controllers of which two correlated convincingly with VSC. Our results underline the importance of multifunctional CD8+ T cell responses during natural control. Especially the role of CXCR5 expressing cytotoxic subsets emphasizes potential surveillance in sites of reservoir persistence and demand further study.


2017 ◽  
Vol 85 (8) ◽  
Author(s):  
Li Zheng ◽  
Yuan Hu ◽  
Yanjuan Wang ◽  
Xibao Huang ◽  
Yuxin Xu ◽  
...  

ABSTRACT Conventional adaptive T cell responses contribute to the pathogenesis of Schistosoma japonicum infection, leading to liver fibrosis. However, the role of gamma-delta (γδ) T cells in this disease is less clear. γδ T cells are known to secrete interleukin-17 (IL-17) in response to infection, exerting either protective or pathogenic functions. In the present study, mice infected with S. japonicum are used to characterize the role of γδ T cells. Combined with the infection of S. japonicum, an extremely significant increase in the percentage of neutrophils in the CD45+ cells was detected (from approximately 2.45% to 46.10% in blood and from 0.18% to 7.34% in spleen). Further analysis identified two different γδ T cell subsets that have different functions in the formation of granulomas in S. japonicum-infected mice. The Vγ1 T cells secrete gamma interferon (IFN-γ) only, while the Vγ2 T cells secrete both IL-17A and IFN-γ. Both subtypes lose the ability to secrete cytokine during the late stage of infection (12 weeks postinfection). When we depleted the Vγ2 T cells in infected mice, the percentage of neutrophils in blood and spleen decreased significantly, the liver fibrosis in the granulomas was reduced, and the level of IL-17A in the serum decreased (P < 0.05). These results suggest that during S. japonicum infection, Vγ2 T cells can recruit neutrophils and aggravate liver fibrosis by secreting IL-17A. This is the first report that a subset of γδ T cells plays a partial role in the pathological process of schistosome infection.


2016 ◽  
Vol 23 (7) ◽  
pp. 638-647 ◽  
Author(s):  
Steven C. Derrick ◽  
Idalia Yabe ◽  
Sheldon Morris ◽  
Siobhan Cowley

Earlier studies aimed at defining protective immunity induced byMycobacterium bovisBCG immunization have largely focused on the induction of antituberculosis CD4+and CD8+T cell responses. Here we describe a vaccine consisting of a BCGΔmmaA4deletion mutant formulated in dimethyl dioctadecyl-ammonium bromide (DDA) withd-(+)-trehalose 6,6′-dibehenate (TDB) (DDA/TDB) adjuvant (A4/Adj) that protected TCRδ−/−mice depleted of CD4+, CD8+, and NK1.1+T cells against an aerosol challenge withM. tuberculosis. These mice were significantly protected relative to mice immunized with a nonadjuvanted BCGΔmmaA4(BCG-A4) mutant and nonvaccinated controls at 2 months and 9 months postvaccination. In the absence of all T cells following treatment with anti-Thy1.2 antibody, the immunized mice lost the ability to control the infection. These results indicate that an unconventional T cell population was mediating protection in the absence of CD4+, CD8+, NK1.1+, and TCRγδ T cells and could exhibit memory. Focusing on CD4−CD8−double-negative (DN) T cells, we found that these cells accumulated in the lungs postchallenge significantly more in A4/Adj-immunized mice and induced significantly greater frequencies of pulmonary gamma interferon (IFN-γ)-producing cells than were seen in the nonvaccinated or nonadjuvanted BCG control groups. Moreover, pulmonary DN T cells from the A4/Adj group exhibited significantly higher IFN-γ integrated median fluorescence intensity (iMFI) values than were seen in the control groups. We also showed that enriched DN T cells from mice immunized with A4/Adj could control mycobacterial growthin vitrosignificantly better than naive whole-spleen cells. These results suggest that formulating BCG in DDA/TDB adjuvant confers superior protection in immunocompromised mice and likely involves the induction of long-lived memory DN T cells.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2033-2033
Author(s):  
Hilit Levy-Barazany ◽  
Liat Pinkas ◽  
Galina Rodionov ◽  
Nitzan Marelly ◽  
Michal Tzadok ◽  
...  

Abstract Graft versus host disease (GvHD) proceeds to be the Achilles' heel of hematopoietic stem cell transplantation, with clinicians continue facing a classic conflict: too much GvHD and the patient is at risk for transplant-related mortality and decreased quality of life; too little GvHD and the patient is at increased risk of relapse of their malignant disease. T cells and antigen presenting cells (APCs) are major components of the hematopoietic G-CSF mobilized peripheral blood cells (PBCs) graft. While GvHD is T cell mediated, the APCs are required for the initiation and maintenance of the GvHD. To reduce the risk for GvHD, grafts are sometimes depleted of their T cells, however, while preventing GvHD, the critically important attributes of graft versus leukemia (GvL) effect and engraftment are reduced significantly. Novel strategies that aim to abrogate or ameliorate GvHD, while preserving engraftment and GvL are of great need. A short incubation (2hr) of G-CSF mobilized PBCs with multimeric Fas ligand (i.e. ApoGraft) selectively induces apoptosis in T cell subsets and APCs (Panels A and B), but not in CD34+ progenitor cells (data not shown). FasL treatment preferentially induces apoptosis in mature T cell subsets which express high levels of Fas (CD95), such as T stem cell memory (TSCM), T central memory (TCM), and T effector memory (TEM) cells, as well as the pro-inflammatory T cell subtypes TH1 and TH17 cells, while no apoptotic signal is detected in the non-expressing CD95 naïve T cells (Panel A). The expression of T cells and APCs activation markers; CD25 and HLA-DR, respectively, is significantly reduced following apoptotic challenge in vitro (Panel C), as well as in transplanted mice (data not shown). Furthermore, upon an activation stimulus with anti CD3/CD28 beads in vitro, ApoGraft derived T cells secrete lower levels of IFN-γ, than G-CSF mobilized PBCs derived T cells (Panel D). To gain deeper understanding of the kinetics of GvHD development in vivo, NSG mice were transplanted with ApoGraft or G-CSF mobilized PBCs. Homing, expansion and differentiation of human leukocytes subtypes within the mice bone marrow, spleen and blood, were monitored 3, 7 and 14 days post transplantation. Decreased levels of T and B cells infiltration and expansion were detected in the spleen (Panels E and F), suggesting reduced formation of allo-reactive T cell clones. Reduced proliferation of these cells was associated with lower levels of IFN-γ secreted to the plasma (Panel H) and was in correlation with reduced GvHD and prolonged survival of the ApoGraft transplanted mice (Panel G). Importantly, we have previously demonstrated both in-vitro and in-vivo that ApoGraft has similar GvL and stem cell engraftment capabilities, compared to control G-CSF mobilized PBCs (data not shown). In conclusion, in contrast to conventional T- cell depletion methods, ApoGraft, an ex-vivo FasL-treated graft, affects both the T-cells and APCs, leading to reduced GvHD, while maintaining GvL and engraftment potential (Panel I). ApoGraft is currently being evaluated in a Phase I/II clinical trial (NCT02828878) in subjects with hematologic malignancies undergoing matched related allo-HSCT. Figure. Figure. Disclosures Levy-Barazany: Cellect Biotherapeutics Ltd: Employment. Pinkas:Cellect Biotherapeutics Ltd: Employment. Rodionov:Cellect Biotherapeutics Ltd: Employment. Marelly:Cellect Biotherapeutics Ltd: Employment. Tzadok:Cellect Biotherapeutics Ltd: Employment. Bakimer:Cellect Biotherapeutics Ltd: Employment. Yarkoni:Cellect Biotherapeutics Ltd: Employment. Peled:Cellect Biotherapeutics Ltd: Consultancy. Zuckerman:Cellect Biotherapeutics Ltd: Consultancy.


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