scholarly journals In Vivo Expression of and Cell-Mediated Immune Responses to the Plasmid-Encoded Virulence-Associated Proteins of Rhodococcus equi in Foals

2007 ◽  
Vol 14 (4) ◽  
pp. 369-374 ◽  
Author(s):  
Stephanie Jacks ◽  
Steeve Giguère ◽  
John F. Prescott
Keyword(s):  
Lymph Node ◽  
Rhodococcus Equi ◽  
Interleukin 4 ◽  
Significant Difference ◽  
In Vivo Expression ◽  
Associated Proteins ◽  
Ifn Γ ◽  
Bronchial Lymph Node

ABSTRACT Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in foals but does not induce disease in adult horses. Virulence of R. equi depends on the presence of a large plasmid, which encodes a family of seven virulence-associated proteins (VapA and VapC to VapH). Eradication of R. equi from the lungs depends on gamma interferon (IFN-γ) production by T lymphocytes. The objectives of the present study were to determine the relative in vivo expression of the vap genes of R. equi in the lungs of infected foals, to determine the recall response of bronchial lymph node (BLN) lymphocytes from foals and adult horses to each of the Vap proteins, and to compare the cytokine profiles of proliferating lymphocytes between foals and adult horses. vapA, vapD, and vapG were preferentially expressed in the lungs of infected foals, and expression of these genes in the lungs was significantly (P < 0.05) higher than that achieved during in vitro growth. VapA and VapC induced the strongest lymphoproliferative responses for foals and adult horses. There was no significant difference in recall lymphoproliferative responses or IFN-γ mRNA expression by bronchial lymph node lymphocytes between foals and adults. In contrast, interleukin 4 (IL-4) expression was significantly higher for adults than for foals for each of the Vap proteins. The ratio of IFN-γ to IL-4 was significantly higher for foals than for adult horses for most Vap proteins. Therefore, foals are immunocompetent and are capable of mounting lymphoproliferative responses of the same magnitude and cytokine phenotype as those of adult horses.

scholarly journals Cooperation between Reactive Oxygen and Nitrogen Intermediates in Killing of Rhodococcus equi by Activated Macrophages

2000 ◽  
Vol 68 (6) ◽  
pp. 3587-3593 ◽  
Author(s):  
Patricia A. Darrah ◽  
Mary K. Hondalus ◽  
Quiping Chen ◽  
Harry Ischiropoulos ◽  
David M. Mosser
Keyword(s):  
Nitric Oxide ◽  
Prolonged Exposure ◽  
Rhodococcus Equi ◽  
Activated Macrophages ◽  
Intracellular Killing ◽  
Oxygen Intermediates ◽  
Bacterial Killing ◽  
Ifn Γ

ABSTRACT Rhodococcus equi is a facultative intracellular bacterium of macrophages which can infect immunocompromised humans and young horses. In the present study, we examine the mechanism of host defense against R. equi by using a murine model. We show that bacterial killing is dependent upon the presence of gamma interferon (IFN-γ), which activates macrophages to produce reactive nitrogen and oxygen intermediates. These two radicals combine to form peroxynitrite (ONOO−), which kills R. equi. Mice deficient in the production of either the high-output nitric oxide pathway (iNOS−/−) or the oxidative burst (gp91 phox−/− ) are more susceptible to lethalR. equi infection and display higher bacterial burdens in their livers, spleens, and lungs than wild-type mice. These in vivo observations, which implicate both nitric oxide (NO) and superoxide (O2 −) in bacterial killing, were reexamined in cell-free radical-generating assays. In these assays, R. equi remains fully viable following prolonged exposure to high concentrations of either nitric oxide or superoxide, indicating that neither compound is sufficient to mediate bacterial killing. In contrast, brief exposure of bacteria to ONOO− efficiently kills virulent R. equi. The intracellular killing of bacteria in vitro by activated macrophages correlated with the production of ONOO− in situ. Inhibition of nitric oxide production by activated macrophages by usingN G-monomethyl-l-arginine blocks their production of ONOO− and weakens their ability to control rhodococcal replication. These studies indicate that peroxynitrite mediates the intracellular killing of R. equiby IFN-γ-activated macrophages.

scholarly journals Investigation of the Role of CD8+ T Cells in Bovine Tuberculosis In Vivo

2003 ◽  
Vol 71 (8) ◽  
pp. 4297-4303 ◽  
Author(s):  
B. Villarreal-Ramos ◽  
M. McAulay ◽  
V. Chance ◽  
M. Martin ◽  
J. Morgan ◽  
...  
Keyword(s):  
Lymph Node ◽  
Bovine Tuberculosis ◽  
The Other ◽  
Cd8 Cells ◽  
Cd8 Cell ◽  
Ifn Γ ◽  
Mycobacterial Antigens

ABSTRACT Mycobacterium bovis is the causative agent of bovine tuberculosis (TB), and it has the potential to induce disease in humans. CD8+ T cells (CD8 cells) have been shown to respond to mycobacterial antigens in humans, cattle, and mice. In mice, CD8 cells have been shown to play a role in protection against mycobacterial infection. To determine the role of CD8 cells in bovine TB in vivo, two groups of calves were infected with the virulent M. bovis strain AF2122/97. After infection, one group was injected with a CD8 cell-depleting monoclonal antibody (MAb), and the other group was injected with an isotype control MAb. Immune responses to mycobacterial antigens were measured weekly in vitro. After 8 weeks, the animals were killed, and postmortem examinations were carried out. In vitro proliferation responses were similar in both calf groups, but in vitro gamma interferon (IFN-γ) production in 24-h whole-blood cultures was significantly higher in control cattle than in CD8 cell-depleted calves. Postmortem examination showed that calves in both groups had developed comparable TB lesions in the lower respiratory tract and associated lymph nodes. Head lymph node lesion scores, on the other hand, were higher in control calves than in CD8 cell-depleted calves. Furthermore, there was significant correlation between the level of IFN-γ and the head lymph node lesion score. These experiments indicate that CD8 cells play a role in the immune response to M. bovis in cattle by contributing to the IFN-γ response. However, CD8 cells may also play a deleterious role by contributing to the immunopathology of bovine TB.

Trastuzumab versus MYL-1401O (a proposed trastuzumab biosimilar) in a phase I bioequivalence study: In vivo and in vitro immunomodulation.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 10-10
Author(s):  
Régine Audran ◽  
Haithem Chtioui ◽  
Anne-Christine Thierry ◽  
Carole Mayor ◽  
Laure Vallotton ◽  
...  
Keyword(s):  
Phase I ◽  
Mononuclear Cell ◽  
Ex Vivo ◽  
Reference Drug ◽  
Gm Csf ◽  
Significant Difference ◽  
Ifn Γ ◽  
The Impact

10 Background: Trastuzumab is a humanized monoclonal antibody targeting breast cancer cells overexpressing the HER2-oncoprotein. During a Phase-I single centre, single dose, randomized, double-blind, cross-over study assessing the bioequivalence of a proposed trastuzumab biosimilar (MYL-1401O) versus the initially marketed drug (Herceptin), we investigated in addition a large panel of pharmacodynamics parameters comparing the immunomodulatory activity of both drugs. Methods: 22 healthy males were included, 19 subjects receiving randomly a single intravenous infusion of MYL-1401O and 22 of Herceptin, separated by 16 to 22 week wash-out. Blood samples drawn pre- and post- infusion were assessed for in vivo serum cytokines induction (IL-1β, IL-2, IL-6, IL-10, IL-12, TNF-α, GM-CSF and IFN-γ) whereas the impact of treatment on mononuclear cell subsets and their level of activation was tested ex vivo. Volunteers’ PBMC (peripheral blood monocnuclear cells) were stimulated in vitro with recall antigens and mitogen for cytokine production. At baseline, we performed in addition a cytokine release assay on PBMC upon stimulation with trastuzumab as a preclinical safety test. Results: Trastuzumab infusion induced a transient and weak peak of serum IL-6 at 6h, and a modulation of mononuclear cell subset profile and level of activation. Notably CD16+ cells frequency decreased at 3h and peaked at 48h. Except for CD8+ T cells, there were no significant differences between Herceptin and its proposed biosimilar ex vivo. PBMC stimulated in vitro with trastuzumab secreted IL-6, TNF-a, IL-1β, GM-CSF, IFN-γ, and IL-10, but no IL-2. There was no significant difference between the two mAbs. Conclusions: Based on these in vivo, ex vivo and in vitro experiments, there is a strong assumption that MYL-1401O is biosimilar to the reference drug Herceptin for its immunomodulation properties as already proven for its bioequivalence. Clinical trial information: 2011-001406-94.

Abstract 255: Modulation Of Cardiac Macrophages As A Strategy For Infarct Healing

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Inthirai Somasuntharam ◽  
Sheridan Carroll ◽  
Milton Brown ◽  
Andres Garcia ◽  
Michael Davis
Keyword(s):  
Wound Healing ◽  
Endothelial Cells ◽  
Delivery System ◽  
Tube Formation ◽  
Interleukin 4 ◽  
Macrophage Response ◽  
Healing Response ◽  
Ifn Γ

Heart failure is the leading cause of death in the developed world and myocardial infarction (MI) is the most common cause. Macrophages are key cells that orchestrate the initial inflammatory as well as later stage wound healing responses following MI. These functions are carried out by pro-inflammatory (M1) and reparative (M2) macrophages respectively. Optimal healing response after MI requires a balancing act of the biphasic macrophage response, so as to not prolong inflammatory signals detrimental to wound healing. Taking advantage of the fact that interleukin-4 (IL-4) activates macrophages towards M2, we hypothesize that delivering IL-4 to the post-MI heart can alter the ratio of M2 to M1 macrophages in the infarct area and induce a better healing response. In this study, we validate our approach in vitro and perform in vitro optimization of a suitable delivery system. RAW 264.7 macrophages were stimulated with IL-4 (10ng/uL) or LPS/IFN-γ (100ng/mL and 10ng/mL) for 24h and gene expression markers (qPCR) and Nitric Oxide (NO) levels (Griess assay) analyzed as indication of M1or M2 activation. Mouse aortic endothelial cells were treated with conditioned media from these cells for 24h and tube formation assessed on matrigel. A bioactive, protease-cleavable polyethylene glycol (PEG) hydrogel delivery system was evaluated for release of functional IL-4 to LPS-activated macrophages. Empty or IL-4 encapsulating hydrogel was placed on a trans-well above LPS-stimulated macrophages. Collagenase I at 0.1mg/mL was applied over 48h to degrade the gels and release IL-4 (n≥3 and p<0.05 considered significant by one-way ANOVA). We demonstrate that IL-4 significantly upregulates M2 markers (MRC-1 and Arg-1) while IFN-γ and LPS upregulate M1 markers (NO and TNF-alpha). We observe enhanced tube density in endothelial cells treated with M2 media while M1 inhibited tube formation. Hydrogel release study shows a significant reduction in NO levels of LPS-stimulated macrophages when IL-4 is released, demonstrating that IL-4 is released from the gel in its bioactive form. In conclusion, we show that macrophages can indeed respond to changing stimuli and adopt distinct activation types and our PEG based hydrogel could be a potential delivery system for in vivo IL-4 delivery.

scholarly journals Neonatal Exposure to a Self-Peptide–Immunoglobulin Chimera Circumvents the Use of Adjuvant and Confers Resistance to Autoimmune Disease by a Novel Mechanism Involving Interleukin 4 Lymph Node Deviation and Interferon γ–mediated Splenic Anergy

1998 ◽  
Vol 188 (11) ◽  
pp. 2007-2017 ◽  
Author(s):  
Booki Min ◽  
Kevin L. Legge ◽  
Christopher Pack ◽  
Habib Zaghouani
Keyword(s):  
T Cells ◽  
Lymph Node ◽  
T Cell ◽  
Proteolipid Protein ◽  
Interleukin 4 ◽  
Target Cells ◽  
Newborn Mice ◽  
Ifn Γ ◽  
Specific Regulation

Induction of neonatal T cell tolerance to soluble antigens requires the use of incomplete Freund's adjuvant (IFA). The side effects that could be associated with IFA and the ill-defined mechanism underlying neonatal tolerance are setbacks for this otherwise attractive strategy for prevention of T cell–mediated autoimmune diseases. Presumably, IFA contributes a slow antigen release and induction of cytokines influential in T cell differentiation. Immunoglobulins (Igs) have long half-lives and could induce cytokine secretion by binding to Fc receptors on target cells. Our hypothesis was that peptide delivery by Igs may circumvent the use of IFA and induce neonatal tolerance that could confer resistance to autoimmunity. To address this issue we used the proteolipid protein (PLP) sequence 139–151 (hereafter referred to as PLP1), which is encephalitogenic and induces experimental autoimmune encephalomyelitis (EAE) in SJL/J mice. PLP1 was expressed on an Ig, and the resulting Ig–PLP1 chimera when injected in saline into newborn mice confers resistance to EAE induction later in life. Mice injected with Ig–PLP1 at birth and challenged as adults with PLP1 developed T cell proliferation in the lymph node but not in the spleen, whereas control mice injected with Ig–W, the parental Ig not including PLP1, developed T cell responses in both lymphoid organs. The lymph node T cells from Ig–PLP1 recipient mice were deviated and produced interleukin (IL)-4 instead of IL-2, whereas the spleen cells, although nonproliferative, produced IL-2 but not interferon (IFN)-γ. Exogenous IFN-γ, as well as IL-12, restored splenic proliferation in an antigen specific manner. IL-12–rescued T cells continued to secrete IL-2 and regained the ability to produce IFN-γ. In vivo, administration of anti–IL-4 antibody or IL-12 restored disease severity. Therefore, adjuvant-free induced neonatal tolerance prevents autoimmunity by an organ-specific regulation of T cells that involves both immune deviation and a new form of cytokine- dependent T cell anergy.

scholarly journals Heterogeneity of Wild Leishmania major Isolates in Experimental Murine Pathogenicity and Specific Immune Response

2001 ◽  
Vol 69 (8) ◽  
pp. 4906-4915 ◽  
Author(s):  
C. Kébaı̈er ◽  
H. Louzir ◽  
M. Chenik ◽  
A. Ben Salah ◽  
K. Dellagi
Keyword(s):  
Immune Response ◽  
Lymph Node ◽  
Leishmania Major ◽  
Mononuclear Cells ◽  
Severe Disease ◽  
Interleukin 4 ◽  
Zoonotic Cutaneous Leishmaniasis ◽  
Tunisian Patients ◽  
Ifn Γ

ABSTRACT Virulence variability was investigated by analyzing the experimental pathogenicity of 19 Leishmania major strains in susceptible BALB/c mice. Twelve strains were isolated from Tunisian patients with zoonotic cutaneous leishmaniasis; seven strains were isolated in Syria (n = 1), Saudi Arabia (n = 2), Jordan (n = 2), or Israel (n = 2). BALB/c mice were injected in the hind footpad with 2 × 106 amastigotes of the various isolates, and lesion progression was recorded weekly for 9 weeks. Interleukin-4 (IL-4) and gamma interferon (IFN-γ) production of lymph node mononuclear cells activated in vitro with parasite antigens were evaluated 5 weeks after infection. We show that disease progression induced by different L. major isolates was largely heterogeneous although reproducible results were obtained when using the same isolate. Interestingly, isolates from the Middle East induced a more severe disease than did the majority of Tunisian isolates. Strains with the highest virulence tend to generate more IL-4 and less IFN-γ in vitro at week 5 postinfection as well as higher levels of early IL-4 mRNA in the lymph node draining the inoculation site at 16 h postinfection. These results suggest that L. major isolates from the field may differ in virulence, which influences the course of the disease induced in mice and the type of immune response elicited by the infected host.

scholarly journals Endogenous Interleukin 4 Is Required for Development of Protective CD4+ T Helper Type 1 Cell Responses to Candida albicans

1998 ◽  
Vol 187 (3) ◽  
pp. 307-317 ◽  
Author(s):  
Antonella Mencacci ◽  
Giuseppe Del Sero ◽  
Elio Cenci ◽  
Cristiana Fè d'Ostiani ◽  
Angela Bacci ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Early Stage ◽  
Interleukin 4 ◽  
T Helper ◽  
Ifn Γ ◽  
Deficient Mice ◽  
Helper Type

Interleukin (IL)-4–deficient mice were used to assess susceptibility to systemic or gastrointestinal Candida albicans infections, as well as parameters of innate and elicited T helper immunity. In the early stage of systemic infection with virulent C. albicans, an unopposed interferon (IFN)-γ response renders IL-4–deficient mice more resistant than wild-type mice to infection. Yet, IL-4–deficient mice failed to efficiently control infection in the late stage and succumbed to it. Defective IFN-γ and IL-12 production, but not IL-12 responsiveness, was observed in IL-4–deficient mice that failed to mount protective T helper type 1 cell (Th1)-mediated acquired immunity in response to a live vaccine strain of the yeast or upon mucosal immunization in vivo. In vitro, IL-4 primed neutrophils for cytokine release, including IL-12. However, late treatment with exogenous IL-4, while improving the outcome of infection, potentiated CD4+ Th1 responses even in the absence of neutrophils. These findings indicate that endogenous IL-4 is required for the induction of CD4+ Th1 protective antifungal responses, possibly through the combined activity on cells of the innate and adaptive immune systems.

scholarly journals Dendritic Cells Induce Immunity and Long-Lasting Protection against Blood-Stage Malaria despite an In Vitro Parasite-Induced Maturation Defect

2004 ◽  
Vol 72 (9) ◽  
pp. 5331-5339 ◽  
Author(s):  
Dodie S. Pouniotis ◽  
Owen Proudfoot ◽  
Violeta Bogdanoska ◽  
Vasso Apostolopoulos ◽  
Theodora Fifis ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Plasmodium Yoelii ◽  
Blood Stage ◽  
Interleukin 4 ◽  
Ifn Γ ◽  
Maturation Defect ◽  
Blood Stage Malaria

ABSTRACT Dendritic cells (DC) suffer a maturation defect following interaction with erythrocytes infected with malaria parasites and become unable to induce protective malaria liver-stage immunity. Here we show that, by contrast, maturation-arrested DC in vitro are capable of the successful induction of antigen-specific gamma interferon (IFN-γ) and interleukin 4 (IL-4) T-cell responses, antibody responses, and potent protection against lethal blood-stage malaria challenge in vivo. Similar results were found with DC pulsed with intact parasitized Plasmodium yoelii or Plasmodium chabaudi erythrocytes. Cross-strain protection was also induced. High levels of protection (80 to 100%) against lethal challenge were evident from 10 days after a single immunization and maintained up to 120 days. Interestingly, correlation studies versus blood-stage protection at different time points suggest that the immune effector mechanisms associated with protection could change over time. Antibody-independent, T-cell- and IL-12-associated protection was observed early after immunization, followed by antibody and IL-4-associated, IFN-γ-independent protection in long-term studies. These results indicate that DC, even when clearly susceptible to parasite-induced maturation defect effects in vitro, can be central to the induction of protection against blood-stage malaria in vivo.

scholarly journals Beryllium, an Adjuvant That Promotes Gamma Interferon Production

2000 ◽  
Vol 68 (7) ◽  
pp. 4032-4039 ◽  
Author(s):  
Julia Y. Lee ◽  
Olga Atochina ◽  
Benjamin King ◽  
Leslie Taylor ◽  
Merle Elloso ◽  
...  
Keyword(s):  
Lymph Node ◽  
Gamma Interferon ◽  
Effective Control ◽  
Interleukin 12 ◽  
Spleen Cells ◽  
Th2 Response ◽  
Th1 Response ◽  
Ifn Γ

ABSTRACT Beryllium is associated with a human pulmonary granulomatosis characterized by an accumulation of CD4+ T cells in the lungs and a heightened specific lymphocyte proliferative response to beryllium (Be) with gamma interferon (IFN-γ) release (i.e., a T helper 1 [Th1] response). While an animal model of Be sensitization is not currently available, Be has exhibited adjuvant effects in animals. The effects of Be on BALB/c mice immunized with soluble leishmanial antigens (SLA) were investigated to determine if Be had adjuvant activity for IFN-γ production, an indicator of the Th1 response. In this strain of Leishmania-susceptible BALB/c mice, a Th2 response is normally observed after in vivo SLA sensitization and in vitro restimulation with SLA. If interleukin-12 (IL-12) is given during in vivo sensitization with SLA, markedly increased IFN-γ production and decreased IL-4 production are detected. We show here that when beryllium sulfate (BeSO4) was added during in vivo sensitization of BALB/c mice with SLA and IL-12, significantly increased IFN-γ production and decreased IL-4 production from lymph node and spleen cells were detected upon in vitro SLA restimulation. No specific responses were observed to Be alone. Lymph node and spleen cells from all mice proliferated strongly and comparably upon in vitro restimulation with SLA and with SLA plus Be; no differences were noted among groups of mice that received different immunization regimens. In vivo, when Be was added to SLA and IL-12 for sensitization of BALB/c mice, more effective control ofLeishmania infection was achieved. This finding has implications for understanding not only the development of granulomatous reactions but also the potential for developing Be as a vaccine adjuvant.

scholarly journals Gamma Interferon Loaded onto Albumin Nanoparticles: In Vitro and In Vivo Activities against Brucella abortus

2007 ◽  
Vol 51 (4) ◽  
pp. 1310-1314 ◽  
Author(s):  
S. Segura ◽  
C. Gamazo ◽  
J. M. Irache ◽  
S. Espuelas
Keyword(s):  
Brucella Abortus ◽  
Bactericidal Effect ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Th2 Cells ◽  
Albumin Nanoparticles ◽  
The Matrix ◽  
Ifn Γ

ABSTRACT The aim of this study was to evaluate the activity of gamma interferon (IFN-γ) when it was either adsorbed onto or loaded into albumin nanoparticles. Brucella abortus-infected macrophages and infected BALB/c mice were selected as the models for testing of the therapeutic potentials of these cytokine delivery systems, in view of the well-established role of IFN-γ-activated macrophages for the control of Brucella sp. infections. Whereas the encapsulation of IFN-γ inside the matrix of nanoparticles completely abrogated its activity, adsorbed IFN-γ increased by 0.75 log unit the bactericidal effect induced by RAW macrophages activated with free IFN-γ, along with a higher level of production of nitric oxide. In infected BALB/c-mice, IFN-γ adsorbed onto nanoparticles was also more active than free cytokine in reducing the number of bacteria in the spleens, and the effect was mediated by an increased ratio of IFN-γ-secreting (Th1) to interleukin-4-secreting (Th2) cells. Overall, albumin nanoparticles would be suitable as carriers that target IFN-γ to macrophages and, thus, potentiate their therapeutic activity.

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