scholarly journals Reduced Pathology following Infection with Transgenic Leishmania major Expressing Murine CD40 Ligand

2007 ◽  
Vol 75 (6) ◽  
pp. 3140-3149 ◽  
Author(s):  
Ann E. Field ◽  
Sagie Wagage ◽  
Sean M. Conrad ◽  
David M. Mosser
Keyword(s):  
Immune Response ◽  
Leishmania Major ◽  
Cd40 Ligand ◽  
High Dose ◽  
Low Doses ◽  
Wild Type ◽  
Safety Concerns ◽  
Transgenic Organisms ◽  
Transgenic Parasites

ABSTRACT Leishmanization is the inoculation of live Leishmania into the host to vaccinate against subsequent infections. This approach has been largely discontinued due to safety concerns. We have previously shown that combining CD40 ligand (CD40L) with Leishmania antigen preferentially induces a type 1 immune response and provides some protection to vaccinated mice (G. Chen, P. A. Darrah, and D. M. Mosser, Infect. Immun. 69:3255-3263, 2001). In the present study, we developed transgenic L. major organisms which express and secrete the extracellular portion of CD40L (L. major CD40LE). We hypothesized that these organisms would be less virulent but more immunogenic than wild-type organisms and therefore be more effective at leishmanization. Transgenic parasites expressing CD40L mRNA and protein were developed. BALB/c mice infected with these parasites developed significantly smaller lesions containing fewer parasites than animals infected with wild-type organisms. Infection of resistant C57BL/6 mice with low doses of transgenic parasites induced a significant amount of protection against subsequent high-dose infection with wild-type organisms. These results demonstrate that transgenic organisms expressing CD40L are less virulent than wild-type organisms while retaining full immunogenicity.

scholarly journals In Vitro Antileishmanial Activity of Nicotinamide

2005 ◽  
Vol 49 (2) ◽  
pp. 808-812 ◽  
Author(s):  
D. Sereno ◽  
A. Monte Alegre ◽  
R. Silvestre ◽  
B. Vergnes ◽  
A. Ouaissi
Keyword(s):  
Leishmania Major ◽  
Growth Arrest ◽  
Antileishmanial Activity ◽  
Vitamin B ◽  
Wild Type ◽  
Intracellular Growth ◽  
Cell Growth Arrest ◽  
Transgenic Parasites

ABSTRACT Our study represents the first report demonstrating the antileishmanial activity of nicotinamide (NAm), a form of vitamin B3. A 5 mM concentration of NAm significantly inhibited the intracellular growth of Leishmania amastigotes and the NAD-dependent deacetylase activity carried by parasites overexpressing Leishmania major SIR2 (LmSIR2). However, the transgenic parasites were as susceptible as the wild-type parasites to NAm-induced cell growth arrest. Therefore, we conclude that NAm inhibits leishmanial growth and that overexpression of LmSIR2 does not overcome this inhibition. The mechanism of the inhibition is not defined but may include other in vivo targets. NAm may thus represent a new antileishmanial agent which could potentially be used in combination with other drugs during therapy.

scholarly journals Leishmania-Derived Trimannose Modulates the Inflammatory Response To Significantly Reduce Leishmania major-Induced Lesions

2017 ◽  
Vol 86 (1) ◽  
Author(s):  
Tara L. Grinnage-Pulley ◽  
Daniel E. K. Kabotso ◽  
Chelsea L. Rintelmann ◽  
Rajarshi Roychoudhury ◽  
Robert G. Schaut ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Parasite Load ◽  
Mannose Receptor ◽  
Lesion Size ◽  
Wild Type ◽  
Cutaneous Lesions ◽  
Content Type ◽  
Latex Beads

ABSTRACTLeishmanialipophosphoglycan (LPG) is a key virulence factor, initiating inflammation resulting in cutaneous lesions. LPG is capped by various oligosaccharides. How these glycans are recognized and how they alter the course ofLeishmaniainfection are poorly understood. Previous studies synthesized α-1,2-trimannose cap sugars on latex beads and demonstrated that C57BL/6 mice coinoculated withLeishmania majorand trimannose-coated beads produced significantly higher levels of interleukin-12p40 (IL-12p40) and other proinflammatory, type 1 cytokines than mice inoculated withL. majoralone within the first 48 h of infection. However, asL. majorinfection typically progress over weeks to months, the role of trimannose in altering disease progression over the course of infection was unknown. Wild-type mice were inoculated with either trimannose-coated or carrier (uncoated) beads, infected withL. majoralone, coinoculated with carrier beads andL. major, or coinoculated with trimannose-coated beads andL. major. Trimannose treatment ofL. major-infected mice decreased the parasite load and significantly decreased the lesion size at 14 days postinfection (p.i.) compared to results for nontreated, infected mice. Infected, trimannose-treated mice had decreased IL-12p40 and IL-10 secretion and increased interferon gamma secretion at 14 days p.i. Mannose receptor knockout (MR−/−) mice lack the ability to detect trimannose. When MR−/−mice were infected withL. majorand treated with trimannose beads, they did not have decreased lesion size.Leishmania-derived trimannose represents a novel immunomodulator that provides early type 1-skewed cytokine production to control the parasite load and alter the course of cutaneous leishmaniasis.

scholarly journals Effective Suppression of Human Immunodeficiency Virus Type 1 through a Combination of Short- or Long-Hairpin RNAs Targeting Essential Sequences for Retroviral Integration

2006 ◽  
Vol 80 (15) ◽  
pp. 7658-7666 ◽  
Author(s):  
Hironori Nishitsuji ◽  
Michinori Kohara ◽  
Mari Kannagi ◽  
Takao Masuda
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Attachment Site ◽  
High Dose ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Small interfering RNA (siRNA) could provide a new therapeutic approach to treating human immunodeficiency virus type 1 (HIV-1) infection. For long-term suppression of HIV-1, emergence of siRNA escape variants must be controlled. Here, we constructed lentiviral vectors encoding short-hairpin RNAs (shRNA) corresponding to conserved target sequences within the integrase (int) and the attachment site (att) genes, both of which are essential for HIV-1 integration. Compared to shRNA targeting of the HIV-1 transcription factor tat (shTat), shRNA against int (shIN) or the U3 region of att (shU3) showed a more potent inhibitory effect on HIV-1 replication in human CD4+ T cells. Infection with a high dose of HIV-1 resulted in the emergence of escape mutants during long-term culture. Of note, limited genetic variation was observed in the viruses resistant to shIN. A combination of shINs against wild-type and escape mutant sequences had a negative effect on their antiviral activities, indicating a potentially detrimental effect when administering multiple shRNA targeting the same region to combat HIV-1 variants. The combination of shIN and shU3 att exhibited the strongest anti-HIV-1 activity, as seen by complete abrogation of viral DNA synthesis and viral integration. In addition, a modified long-hairpin RNA spanning the 50 nucleotides in the shIN target region effectively suppressed wild-type and shIN-resistant mutant HIV-1. These results suggest that targeting of incoming viral RNA before proviral DNA formation occurs through the use of nonoverlapping multiple siRNAs is a potent approach to achieving sustained, efficient suppression of highly mutable viruses, such as HIV-1.

scholarly journals Transcriptional analysis of lymphoid tissues from infected nonhuman primates reveals the basis for attenuation and immunogenicity of an Ebola virus encoding a mutant VP35 protein

2021 ◽  
Author(s):  
Amanda Pinski ◽  
Courtney Woolsey ◽  
Allen Jankeel ◽  
Robert Cross ◽  
Christopher F. Basler ◽  
...  
Keyword(s):  
Immune Response ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Transcriptional Response ◽  
Transcriptional Analysis ◽  
Lymphoid Tissues ◽  
High Dose ◽  
Type I ◽  
Wild Type ◽  
Transcriptional Responses

Infection with Zaire ebolavirus (EBOV), a member of the Filoviridae family, causes a disease characterized by high levels of viremia, aberrant inflammation, coagulopathy, and lymphopenia. EBOV initially replicates in lymphoid tissues and disseminates via dendritic cells (DCs) and monocytes to liver, spleen, adrenal gland and other secondary organs. EBOV protein VP35 is a critical immune evasion factor that inhibits type I interferon signaling and DC maturation. Nonhuman primates immunized with a high dose (5x105 PFU) of recombinant EBOV containing a mutated VP35 (VP35m) are protected from challenge with wild-type (wt)EBOV. This protection is accompanied by a transcriptional response in the peripheral blood reflecting a regulated innate immune response and a robust induction of adaptive immune genes. However, the host transcriptional response to VP35m in lymphoid tissues has not been evaluated. Therefore, we conducted a transcriptional analysis of axillary and inguinal lymph nodes, and spleen tissues of NHPs infected with a low dose (2x104 PFU) of VP35m and then backchallenged with a lethal dose of wtEBOV. VP35m induced early transcriptional responses in lymphoid tissues that are distinct from those observed in wtEBOV challenge. Specifically, we detected robust antiviral innate and adaptive responses and fewer transcriptional changes in genes with roles in angiogenesis, apoptosis and inflammation. Two of three macaques survived wtEBOV backchallenge, with only the nonsurvivor displaying a transcriptional response reflecting Ebola virus disease. These data suggest that VP35 is a key modulator of early host responses in lymphoid tissues, thereby regulating disease progression and severity following EBOV challenge. IMPORTANCE Zaire Ebola virus (EBOV) infection causes a severe and often fatal disease characterized by inflammation, coagulation defects, and organ failure driven by a defective host immune response. Lymphoid tissues are key sites of EBOV pathogenesis and generation of an effective immune response to infection. A recent study demonstrated that infection with an EBOV encoding a mutant VP35, a viral protein that antagonizes host immunity, can protect nonhuman primates (NHPs) against lethal EBOV challenge. However, no studies have examined the response to this mutant EBOV in lymphoid tissues. Here, we characterize the gene expression of lymphoid tissues from NHPs challenged with the mutant EBOV and subsequently with wild-type EBOV to identify signatures of a protective host response. Our findings are critical for elucidating viral pathogenesis, mechanisms of host antagonism and the role of lymphoid organs in protective responses to EBOV to improve the development of antivirals and vaccines against EBOV.

scholarly journals Deletion of Interleukin-4 Receptor Alpha-Responsive Keratinocytes in BALB/c Mice Does Not Alter Susceptibility to Cutaneous Leishmaniasis

2018 ◽  
Vol 86 (12) ◽  
Author(s):  
Melissa Govender ◽  
Ramona Hurdayal ◽  
Berenice Martinez-Salazar ◽  
Kaya Gqada ◽  
Shandre Pillay ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Parasite Burden ◽  
Interleukin 4 ◽  
High Dose ◽  
Littermate Control ◽  
Content Type ◽  
Receptor Alpha ◽  
Th2 Immune Response

ABSTRACTThe skin microenvironment at the site of infection plays a role in the early events that determine protective T helper 1/type 1 immune responses during cutaneous leishmaniasis (CL) infection. During CL in nonhealing BALB/c mice, early interleukin-4 (IL-4) can instruct dendritic cells for protective Th1 immunity. Additionally, keratinocytes, which are the principal cell type in the skin epidermis, have been shown to secrete IL-4 early afterLeishmania majorinfection. Here, we investigated whether IL-4/IL-13 signaling via the common IL-4 receptor alpha chain (IL-4Rα) on keratinocytes contributes to susceptibility during experimental CL. To address this, keratinocyte-specific IL-4Rα-deficient (KRT14creIL-4Rα−/lox) mice on a BALB/c genetic background were generated by gene targeting and site-specific recombination (Cre/loxP) under the control of the keratinocyte-specifickrt14locus. Following high-dose infection withL. majorIL-81 and LV39 promastigotes subcutaneously in the footpad, footpad swelling, parasite burden, IFN-γ/IL-4/IL-13 cytokine production, and type 1 and type 2 antibody responses were similar between KRT14creIL-4Rα−/loxand littermate control IL-4Rα−/loxBALB/c mice. An intradermal infection with low-doseL. majorIL-81 and LV39 promastigotes in the ear showed results in infected KRT14creIL-4Rα−/loxBALB/c mice similar to those of littermate control IL-4Rα−/loxBALB/c mice, with the exception of a significant decrease observed in parasite burden only at the site of LV39 infection in the ear. Collectively, our results show that autocrine and paracrine signaling of IL-4/IL-13 through the IL-4Rα chain on keratinocytes does not influence the establishment of a nonhealing Th2 immune response in BALB/c mice duringL. majorinfection.

scholarly journals Bacterial Lipoprotein-Based Vaccines Induce Tumor Necrosis Factor-Dependent Type 1 Protective Immunity against Leishmania major

2002 ◽  
Vol 70 (1) ◽  
pp. 240-248 ◽  
Author(s):  
Javier Cote-Sierra ◽  
Amin Bredan ◽  
Carmen M. Toldos ◽  
Benoit Stijlemans ◽  
Lea Brys ◽  
...  
Keyword(s):  
Immune Response ◽  
Tumor Necrosis Factor ◽  
Immune Responses ◽  
Tumor Necrosis ◽  
Leishmania Major ◽  
Rational Approach ◽  
Tnf Α ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Immunity against Leishmania major requires rapid induction of a type 1 immune response in which tumor necrosis factor alpha (TNF-α) plays an essential role. Hence, vaccination strategies that simulate the protective immune response found in hosts that have recovered from natural infection provide a rational approach to combat leishmaniasis. One method for optimizing the qualitative and quantitative immune responses after vaccination is to use an adjuvant. In this study we demonstrate that the OprI lipoprotein (L-OprI) from Pseudomonas aeruginosa induces a long-term cellular (gamma interferon [IFN-γ]) and humoral (immunoglobulin G2a) type 1 immune response against a truncated 32-kDa version (COOHgp63) of the 63-kDa major cell surface glycoprotein gp63. By contrast, immunization with COOHgp63 either fused to OprI nonlipoprotein or with no adjuvant did not result in the induction of type 1 immune responses. The adjuvanticity of L-OprI is strongly dependent on its capacity to induce TNF-α, since generation of type 1 immune responses is clearly delayed and impaired in TNF-α−/− mice. Vaccination with L-OprICOOHgp63 fusion protein protected BALB/c mice against L. major infection for at least 19 weeks. Vaccinated mice were largely free of lesions or clearly controlled lesion size on termination of the experiment. The control of disease progression in mice vaccinated with L-OprICOOHgp63 was associated with enhancement of antigen-specific IFN-γ production. These data indicate that bacterial lipoproteins constitute appropriate adjuvants to include in vaccines against diseases in which type 1 immune responses are important for protection.

scholarly journals Prevention of Streptozotocin-Induced Diabetic Nephropathy by MG132: Possible Roles of Nrf2 and IκB

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Lili Kong ◽  
Yangwei Wang ◽  
Manyu Luo ◽  
Yi Tan ◽  
Wenpeng Cui ◽  
...  
Keyword(s):  
Renal Function ◽  
Diabetic Nephropathy ◽  
Nuclear Factor ◽  
Low Doses ◽  
Wild Type ◽  
Renal Protection ◽  
Proteasomal Activity ◽  
Significant Attenuation ◽  
Proteasomal Inhibitor

Our previous study showed that proteasomal inhibitor MG132 can prevent diabetic nephropathy (DN) along with upregulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). The present study was to investigate whether MG132 can prevent DN in wild-type and Nrf2-KO mice. Type 1 diabetes was induced in wild-type and Nrf2-KO mice by multiple low doses of streptozotocin. Two weeks after streptozotocin injection, both wild-type and Nrf2-KO mice were randomly divided into four groups: control, MG132, DM, and DM/MG132. MG132 (10 μg/kg/day) or vehicle was administered intraperitoneally for 4 months. Renal function, morphology, and biochemical changes were measured after 4-month treatment with MG132. MG132 treatment suppressed proteasomal activity in the two genotypes. In wild-type mice, MG132 attenuated diabetes-induced renal dysfunction, fibrosis, inflammation, and oxidative damage along with increased Nrf2 and IκB expression. Deletion of Nrf2 gene resulted in a partial, but significant attenuation of MG132 renal protection in Nrf2-KO mice compared with wild-type mice. MG132-increased IκB expression was not different between wild-type and Nrf2-KO mice. This work indicates that MG132 inhibits diabetes-increased proteasomal activity, resulting in Nrf2 and IκB upregulation and renal protection, which could be used as a strategy to prevent diabetic nephropathy.

Leishmania major H-line attenuated under pressure of gentamicin, induces a Th1 response which protects susceptible BALB/c mice against infection with virulent L. major

Parasitology ◽  
2009 ◽  
Vol 136 (11) ◽  
pp. 1243-1250 ◽  
Author(s):  
HAMID DANESHVAR ◽  
RICHARD BURCHMORE ◽  
PAUL HAGAN ◽  
R. STEPHEN PHILLIPS
Keyword(s):  
Immune Response ◽  
Lymph Node ◽  
Cell Line ◽  
Leishmania Major ◽  
Wild Type ◽  
Th1 Response ◽  
Th2 Responses ◽  
Draining Lymph Node ◽  
Ifn Γ

SUMMARYAn attenuated line of Leishmania major (L. major H-line) has been established by culturing promastigotes in vitro under gentamicin pressure. A modification of the previously described method for the generation of attenuated L. major is described, giving rise to attenuated parasites after 8 rather than 12 subpassages. No lesions developed in BALB/c mice infected with L. major H-line, whereas L. major wild-type (WT) induced a Th2 like response with progressive lesions. Analysis of splenocyte IFN-γ and IL-4 production following stimulation with promastigotes shows that the L. major H-line preferentially induces Th1-like responses and possibly down-regulates Th2 responses in BALB/c mice. L. major H-line parasites remained localized in the skin and draining lymph node, whereas L. major WT parasites disseminated into the visceral organs of BALB/c mice. Mice infected with L. major H-line acquired some resistance against L. major WT. These results show that the attenuated cell line of L. major is not only avirulent but that it may also modulate the host immune response.

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