scholarly journals Clearance of Virulent but Not Avirulent Rhodococcus equi from the Lungs of Adult Horses Is Associated with Intracytoplasmic Gamma Interferon Production by CD4+ and CD8+ T Lymphocytes

2003 ◽  
Vol 10 (2) ◽  
pp. 208-215 ◽  
Author(s):  
Stephen A. Hines ◽  
Diana M. Stone ◽  
Melissa T. Hines ◽  
Debby C. Alperin ◽  
Donald P. Knowles ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Virulent Strain ◽  
Lavage Fluid ◽  
Rhodococcus Equi ◽  
Gamma Interferon ◽  
Effective Vaccine ◽  
Virulence Plasmid ◽  
Flow Cytometric Method ◽  
Ifn Γ ◽  
Rhodococcal Pneumonia

ABSTRACT Rhodococcus equi is a gram-positive bacterium that infects alveolar macrophages and causes rhodococcal pneumonia in horses and humans. The virulence plasmid of R. equi appears to be required for both pathogenicity in the horse and the induction of protective immunity. An understanding of the mechanisms by which virulent R. equi circumvents protective host responses and by which bacteria are ultimately cleared is important for development of an effective vaccine. Six adult horses were challenged with either virulent R. equi or an avirulent, plasmid-cured derivative. By using a flow cytometric method for intracytoplasmic detection of gamma interferon (IFN-γ) in equine bronchoalveolar lavage fluid (BALF) cells, clearance of the virulent strain was shown to be associated with increased numbers of pulmonary CD4+ and CD8+ T lymphocytes producing IFN-γ. There was no change in IFN-γ-positive cells in peripheral blood, suggesting that a type 1 recall response at the site of challenge was protective. The plasmid-cured strain of R. equi was cleared in horses without a significant increase in IFN-γ-producing T lymphocytes in BALF. In contrast to these data, a previous report in foals suggested an immunomodulating role for R. equi virulence plasmid-encoded products in downregulating IFN-γ expression by equine CD4+ T lymphocytes. Intracytoplasmic detection of IFN-γ provides a method to better determine whether modulation of macrophage-activating cytokines by virulent strains occurs uniquely in neonates and contributes to their susceptibility to rhodococcal pneumonia.

scholarly journals Experimental Infection of Neonatal Foals with Rhodococcus equi Triggers Adult-Like Gamma Interferon Induction

2007 ◽  
Vol 14 (6) ◽  
pp. 669-677 ◽  
Author(s):  
Stephanie Jacks ◽  
Steeve Giguère ◽  
P. Cynda Crawford ◽  
William L. Castleman
Keyword(s):  
T Lymphocytes ◽  
Bronchoalveolar Lavage Fluid ◽  
Lavage Fluid ◽  
Rhodococcus Equi ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Intracellular Pathogen ◽  
Interferon Induction ◽  
Ifn Γ ◽  
Bronchial Lymph Node

ABSTRACT Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in young foals but does not induce disease in immunocompetent adult horses. Clearance of R. equi depends mainly on gamma interferon (IFN-γ) production by T lymphocytes, whereas the predominance of interleukin 4 (IL-4) is detrimental. Young foals, like neonates of many other species, are generally deficient in the ability to produce IFN-γ. The objective of this study was to compare the cytokine profiles, as well as cell-mediated and antibody responses, of young foals to those of adult horses following intrabronchial challenge with R. equi. The lymphoproliferative responses of bronchial lymph node (BLN) cells to concanavalin A were significantly higher in foals than in adult horses. In contrast, adult horses had significantly higher lymphoproliferative responses to R. equi antigens than did foals. Infected foals had significantly lower IL-4 mRNA expression but significantly higher IFN-γ expression and IFN-γ/IL-4 ratio in R. equi-stimulated BLN lymphocytes than did infected adults. Infection with R. equi in foals resulted in a significant increase in the percentage of T lymphocytes and CD4+ T lymphocytes in bronchoalveolar lavage fluid in association with a significant decrease in the percentage of these cell populations in BLNs. Infection of foals also resulted in a marked increase in serum immunoglobulin Ga (IgGa) and IgGb levels, resulting in concentrations in serum that were significantly higher than those of adult horses. This study demonstrates that the immune response to R. equi in foals is not biased toward IL-4 and is characterized by the predominant induction of IFN-γ.

scholarly journals Modulation of Cytokine Response of Pneumonic Foals by Virulent Rhodococcus equi

1999 ◽  
Vol 67 (10) ◽  
pp. 5041-5047 ◽  
Author(s):  
Steeve Giguère ◽  
Bruce N. Wilkie ◽  
John F. Prescott
Keyword(s):  
T Lymphocytes ◽  
Mrna Expression ◽  
Rhodococcus Equi ◽  
Cytokine Response ◽  
Interleukin 12 ◽  
Virulence Plasmid ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ

ABSTRACT The ability of Rhodococcus equi to induce pneumonia in foals depends on the presence of an 85- to 90-kb plasmid. In this study, we evaluated whether plasmid-encoded products mediate virulence by modulating the cytokine response of foals. Foals infected intrabronchially with a virulence plasmid-containing strain of R. equi had similar gamma interferon (IFN-γ) and interleukin-12 (IL-12) p35 but significantly higher IL-1β, IL-10, IL-12 p40, and tumor necrosis factor alpha (TNF-α) mRNA expression in lung tissue compared to foals infected with the plasmid-cured derivative. IFN-γ mRNA expression levels in CD4+ T lymphocytes isolated from bronchial lymph nodes (BLN) were similar for the two groups of R. equi-infected foals on day 3 postinfection. However, on day 14, in association with pneumonia and marked multiplication of virulentR. equi but with complete clearance of the plasmid-cured derivative, IFN-γ mRNA expression in BLN CD4+ T lymphocytes was significantly (P < 0.001) higher in foals infected with the plasmid-cured derivative. These results suggests an immunomodulating role for R. equi virulence plasmid-encoded products in downregulating IFN-γ mRNA expression by CD4+ T lymphocytes.

scholarly journals Rhodococcus equi Secreted Antigens Are Immunogenic and Stimulate a Type 1 Recall Response in the Lungs of Horses Immune to R. equi Infection

2003 ◽  
Vol 71 (11) ◽  
pp. 6329-6337 ◽  
Author(s):  
Andrea K. Kohler ◽  
Diana M. Stone ◽  
Melissa T. Hines ◽  
Barbara A. Byrne ◽  
Debra C. Alperin ◽  
...  
Keyword(s):  
Opportunistic Pathogen ◽  
Lavage Fluid ◽  
Rhodococcus Equi ◽  
Virulence Plasmid ◽  
Protective Antigens ◽  
Growth System ◽  
Life Threatening ◽  
Rhodococcal Pneumonia

ABSTRACT Rhodococcus equi is an opportunistic pathogen in immunocompromised humans and an important primary pathogen in young horses. Although R. equi infection can produce life-threatening pyogranulomatous pneumonia, most foals develop a protective immune response that lasts throughout life. The antigen targets of this protective response are currently unknown; however, Mycobacterium tuberculosis is a closely related intracellular pathogen and provides a model system. Based on previous studies of M. tuberculosis protective antigens released into culture filtrate supernatant (CFS), a bacterial growth system was developed for obtaining R. equi CFS antigens. Potential immunogens for prevention of equine rhodococcal pneumonia were identified by using immunoblots. The 48-h CFS contained five virulence-associated protein bands that migrated between 12 and 24 kDa and were recognized by sera from R. equi-infected foals and immune adult horses. Notably, the CFS contained the previously characterized proteins VapC, VapD, and VapE, which are encoded by genes on the R. equi virulence plasmid. R. equi CFS was also examined for the ability to stimulate a type 1-like memory response in immune horses. Three adult horses were challenged with virulent R. equi, and cells from the bronchoalveolar lavage fluid were recovered before and 1 week after challenge. In vitro stimulation of pulmonary T-lymphocytes with R. equi CFS resulted in significant proliferation and a significant increase in gamma interferon mRNA expression 1 week after challenge. These results were consistent with a memory effector response in immune adult horses and provide evidence that R. equi CFS proteins are antigen targets in the immunoprotective response against R. equi infection.

scholarly journals Identification of Pulmonary T-Lymphocyte and Serum Antibody Isotype Responses Associated with Protection against Rhodococcus equi

2002 ◽  
Vol 9 (6) ◽  
pp. 1270-1276 ◽  
Author(s):  
A. Marianela Lopez ◽  
Melissa T. Hines ◽  
Guy H. Palmer ◽  
Debra C. Alperin ◽  
Stephen A. Hines
Keyword(s):  
Bronchoalveolar Lavage ◽  
Bronchoalveolar Lavage Fluid ◽  
Vaccine Development ◽  
Serum Antibody ◽  
Lavage Fluid ◽  
Rhodococcus Equi ◽  
Effective Vaccine ◽  
Igg Isotypes ◽  
Ifn Γ ◽  
Stimulation Of

ABSTRACT Rhodococcus equi infects and causes pneumonia in foals between 2 and 4 months of age but does not induce disease in immunocompetent adults, which are immune and remain clinically normal upon challenge. Understanding the protective response against R. equi in adult horses is important in the development of vaccine strategies, since those mechanisms likely reflect the protective phenotype that an effective vaccine would generate in the foal. Twelve adult horses were challenged with virulent R. equi and shown to be protected against clinical disease. Stimulation of cells obtained from bronchoalveolar lavage fluid with either R. equi or the vaccine candidate protein VapA resulted in significant proliferation and a significant increase in the level of gamma interferon (IFN-γ) expression by day 7 postchallenge. The levels of interleukin-4 expression were also increased at day 7 postchallenge; however, this increase was not antigen specific. Anamnestic increases in the levels of binding to R. equi and VapA of all immunoglobulin G (IgG) antibody isotypes [IgGa, IgGb, IgG(T)] examined were detected postchallenge. The levels of R. equi- and VapA-specific IgGa and IgGb antibodies, the IgG isotypes that preferentially opsonize and fix complement in horses, were dramatically enhanced postchallenge. The antigen-specific proliferation of bronchoalveolar lavage fluid cells, the levels of IFN-γ expression by these cells, and the anamnestic increases in the levels of opsonizing IgG isotypes are consistent with stimulation of a memory response in immune adult horses and represent correlates for vaccine development in foals.

scholarly journals Populations of Human T Lymphocytes That Traverse the Vascular Endothelium Stimulated by Borrelia burgdorferi Are Enriched with Cells That Secrete Gamma Interferon

2004 ◽  
Vol 72 (3) ◽  
pp. 1530-1536 ◽  
Author(s):  
Edna I. Gergel ◽  
Martha B. Furie
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Vascular Endothelium ◽  
Human Peripheral Blood ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Ifn Γ

ABSTRACT Some diseases are characterized by prevalence in the affected tissues of type 1 T lymphocytes, which secrete gamma interferon (IFN-γ) and other proinflammatory cytokines. For example, type 1 T cells predominate in the lesions of patients with Lyme disease, which is caused by the bacterium Borrelia burgdorferi. We used an in vitro model of the blood vessel wall to test the premise that the vascular endothelium actively recruits circulating type 1 T cells to such lesions. When T lymphocytes isolated from human peripheral blood were examined, the populations that traversed monolayers of resting human umbilical vein endothelial cells (HUVEC) or HUVEC stimulated by interleukin-1β or B. burgdorferi were markedly enriched for T cells that produced IFN-γ compared to the initially added population of T cells. No enrichment was seen for cells that produced interleukin-4, a marker for type 2 T lymphocytes. Very late antigen-4 and CD11/CD18 integrins mediated passage of the T cells across both resting and stimulated HUVEC, and the endothelium-derived chemokine CCL2 (monocyte chemoattractant protein 1) was responsible for the enhanced migration of T cells across stimulated HUVEC. These results suggest that the vascular endothelium may contribute to the selective accumulation of type 1 T cells in certain pathological lesions, including those of Lyme disease.

scholarly journals Gamma Interferon Expression in CD8+ T Cells Is a Marker for Circulating Cytotoxic T Lymphocytes That Recognize an HLA A2-Restricted Epitope of Human Cytomegalovirus Phosphoprotein pp65

2001 ◽  
Vol 8 (3) ◽  
pp. 628-631 ◽  
Author(s):  
Smita A. Ghanekar ◽  
Laurel E. Nomura ◽  
Maria A. Suni ◽  
Louis J. Picker ◽  
Holden T. Maecker ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Human Cytomegalovirus ◽  
Surrogate Marker ◽  
Gamma Interferon ◽  
Strong Positive Correlation ◽  
Specific Lysis ◽  
Cytokine Flow Cytometry ◽  
Ifn Γ

ABSTRACT Antigen-specific CD8+ T cells with cytotoxic activity are often critical in immune responses to infectious pathogens. To determine whether gamma interferon (IFN-γ) expression is a surrogate marker for cytotoxic T lymphocytes (CTL), human cytomegalovirus-specific CTL responses were correlated with CD8+ T-cell IFN-γ expression determined by cytokine flow cytometry. A strong positive correlation was observed between specific lysis of peptide-pulsed targets in a 51Cr release assay and frequencies of peptide-activated CD8+ T cells expressing IFN-γ at 6 h (r 2 = 0.72) or 7 days (r 2 = 0.91). Enumeration of responding cells expressing perforin, another marker associated with CTL, did not improve this correlation. These results demonstrate that IFN-γ expression can be a functional surrogate for identification of CTL precursor cells.

scholarly journals Key Role of Effector Memory CD4+T Lymphocytes in a Short-Incubation Heparin-Binding Hemagglutinin Gamma Interferon Release Assay for the Detection of Latent Tuberculosis

2014 ◽  
Vol 21 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Chloé Wyndham-Thomas ◽  
Véronique Corbière ◽  
Violette Dirix ◽  
Kaatje Smits ◽  
Fanny Domont ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Latent Tuberculosis ◽  
Gamma Interferon ◽  
Effector Memory ◽  
The Novel ◽  
Infection Status ◽  
Heparin Binding ◽  
Content Type ◽  
Release Assay ◽  
Ifn Γ

ABSTRACTThe treatment of latent tuberculosis infection (LTBI) in target populations is one of the current WHO strategies for preventing active tuberculosis (TB) infection and reducing theMycobacterium tuberculosisreservoir. Therefore, powerful LTBI screening tools are indispensable. A gamma interferon release assay (IGRA) in response to the stimulation of peripheral blood mononuclear cells by the latency antigen native heparin-binding hemagglutinin (nHBHA-IGRA) has proven its potential for this purpose. We have evaluated its possible optimization through a reduction of incubation time from 96 to 24 h, while compensating for this by adding interleukin 7 (IL-7) to the medium. We have also investigated the phenotypes of the gamma interferon (IFN-γ)-producing cells after both short and long incubation times. One hundred thirty-one nonimmunocompromised patients were recruited from 3 Brussels-based university hospitals. They were divided into 1 of 4 subgroups according to theirM. tuberculosisinfection status (LTBI, TB infection, undeterminedM. tuberculosisinfection status, and noninfected controls). The novel 24-h nHBHA-IGRA was performed for all subjects, and a simultaneous 96-h classical HBHA-IGRA was performed for 79 individuals. The results showed a good correlation between the two tests, and the novel 24-h nHBHA-IGRA maintained the principal advantages of the classical test, namely, a high specificity for LTBI diagnosis, an absence of interference ofMycobacterium bovisBCG vaccination during infancy, and a relative discrimination between LTBI and TB infection. Whereas the commercialized IGRAs show a greater sensitivity for recent than for remoteM. tuberculosisinfections, the 24-h nHBHA-IGRA appears to have comparable diagnostic powers for recent and remote LTBI. The IFN-γ detected by the 24-h nHBHA-IGRA was mainly secreted by effector memory CD4+T lymphocytes, a finding suggestive of continuous HBHA presentation during latency.

scholarly journals Immunomodulatory Role of Endogenous Interleukin-18 in Gamma Interferon-Mediated Resolution of Replicative Legionella pneumophila Lung Infection

2000 ◽  
Vol 68 (12) ◽  
pp. 6567-6573 ◽  
Author(s):  
Joan K. Brieland ◽  
Craig Jackson ◽  
Steve Hurst ◽  
David Loebenberg ◽  
Tony Muchamuel ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Lavage Fluid ◽  
Lung Infection ◽  
Gamma Interferon ◽  
Pcr Analysis ◽  
Interleukin 18 ◽  
Legionnaires Disease ◽  
Ifn Γ

ABSTRACT The in vivo role of endogenous interleukin-18 (IL-18) in modulating gamma interferon (IFN-γ)-mediated resolution of replicativeLegionella pneumophila lung infection was assessed using a murine model of Legionnaires' disease. Intratracheal inoculation of A/J mice with virulent bacteria (106 L. pneumophila organisms per mouse) resulted in induction of IL-18 protein in bronchoalveolar lavage fluid (BALF) and intrapulmonary expression of IL-18 mRNA. Real-time quantitative RT-PCR analysis of infected lung tissue demonstrated that induction of IL-18 in BALF preceded induction of IL-12 and IFN-γ mRNAs in the lung. Blocking intrapulmonary IL-18 activity by administration of a monoclonal antibody (MAb) to the IL-18 receptor (anti-IL-18R MAb) prior toL. pneumophila infection inhibited induction of intrapulmonary IFN-γ production but did not significantly alter resolution of replicative L. pneumophila lung infection. In contrast, blocking endogenous IL-12 activity by administration of anti-IL-12 MAb) alone or in combination with anti-IL-18R MAb inhibited induction of intrapulmonary IFN-γ and resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection. Taken together, these results demonstrate that IL-18 plays a key role in modulating induction of IFN-γ in the lung in response to L. pneumophila and that together with IL-12, IL-18 regulates intrapulmonary growth of the bacteria.

scholarly journals Identification of Vaccine Candidate Peptides in the NcSRS2 Surface Protein of Neospora caninum by Using CD4+ Cytotoxic T Lymphocytes and Gamma Interferon-Secreting T Lymphocytes of Infected Holstein Cattle

2005 ◽  
Vol 73 (3) ◽  
pp. 1321-1329 ◽  
Author(s):  
Lauren M. Staska ◽  
Christopher J. Davies ◽  
Wendy C. Brown ◽  
Travis C. McGuire ◽  
Carlos E. Suarez ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
T Lymphocyte ◽  
Peripheral Blood ◽  
Vaccine Development ◽  
Neospora Caninum ◽  
Gamma Interferon ◽  
Target Cells ◽  
Holstein Cattle ◽  
Ifn Γ

ABSTRACT Previously, our laboratory showed that Holstein cattle experimentally infected with Neospora caninum develop parasite-specific CD4+ cytotoxic T lymphocytes (CTL) that lyse infected, autologous target cells through a perforin-granzyme pathway. To identify specific parasite antigens inducing bovine CTL and helper T-lymphocyte responses for vaccine development against bovine neosporosis, the tachyzoite major surface proteins NcSAG1 and NcSRS2 were targeted. In whole tachyzoite antigen-expanded bovine T-lymphocyte lines, recombinant NcSRS2 induced potent memory CD4+- and CD8+-T-lymphocyte activation, as indicated by proliferation and gamma interferon (IFN-γ) secretion, while recombinant NcSAG1 induced a minimal memory response. Subsequently, T-lymphocyte epitope-bearing peptides of NcSRS2 were mapped by using overlapping peptides covering the entire NcSRS2 sequence. Four experimentally infected cattle with six different major histocompatibility complex (MHC) class II haplotypes were the source of immune cells used to identify NcSRS2 peptides presented by Holstein MHC haplotypes. NcSRS2 peptides were mapped by using IFN-γ secretion by rNcSRS2-stimulated, short-term T-lymphocyte cell lines, IFN-γ enzyme-linked immunospot (ELISPOT) assay with peripheral blood mononuclear cells, and 51Cr release cytotoxicity assay of rNcSRS2-stimulated effector cells. Four N. caninum-infected Holstein cattle developed NcSRS2 peptide-specific T lymphocytes detected ex vivo in peripheral blood by IFN-γ ELISPOT and in vitro by measuring T-lymphocyte IFN-γ production and cytotoxicity. An immunodominant region of NcSRS2 spanning amino acids 133 to 155 was recognized by CD4+ T lymphocytes from the four cattle. These findings support investigation of subunit N. caninum vaccines incorporating NcSRS2 gene sequences or peptides for induction of NcSRS2 peptide-specific CTL and IFN-γ-secreting T lymphocytes in cattle with varied MHC genotypes.

scholarly journals Characterization of Immunogenic and Protective Properties of the Modified Variants of the Strain Francisella tularensis 15 NIIEG

2020 ◽  
pp. 62-69
Author(s):  
A. S. Kartseva ◽  
O. V. Kalmantaeva ◽  
M. V. Silkina ◽  
T. I. Kombarova ◽  
V. M. Pavlov ◽  
...  
Keyword(s):  
B Lymphocytes ◽  
Francisella Tularensis ◽  
Virulent Strain ◽  
The Body ◽  
Effective Vaccine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Functional Markers ◽  
Protective Properties ◽  
Ifn Γ ◽  
T Helpers

Francisella tularensis is an intracellular bacterium that causes tularemia. Progress in creating a safe and effective vaccine for the prevention of tularemia is challenging due to a lack of knowledge about immunological parameters indicative of protective adaptive immunity. Objective of the research was to assess the effect of modifications of the F. tularensis 15 NIIEG genome on the immunogenic and protective properties of F. tularensis 15/23-1ΔrecA and F. tularensis 15/23-1/sodBΔrecA strains. Materials and methods. Multi-parameter flow cytometry and the measurement of secreted cytokines were used to characterize the responses of mouse spleen lymphocytes in response to re-stimulation of F. tularensis with acid-insoluble complex (AIC) in vitro. Also, the titers of specific antibodies to F. tularensis lipopolysaccharide in blood serum were analyzed by enzyme-linked immunosorbent assay. Results and discussion. It has been shown that immunization with the studied strains led to a significant increase in CD4+ and/or CD8+ T cells capable of expressing functional markers: CD69, CD25 and/or CD28; an increase in the subpopulation of T-helpers synthesizing IFN-γ. In the body of immune mice, a pool of B-lymphocytes was formed, capable of secreting IFN-γ in response to their stimulation with AIC. Immunization with the strain 15/23-1/sodBΔrecA provided 70% protection in mice from intranasal infection with a virulent strain of F. tularensis SchuS4. More pronounced protective properties were associated with the activation of not only B-lymphocytes and T-helpers, but also with the simultaneous activation of cytotoxic T-lymphocytes.

Sign in / Sign up

Export Citation Format

Share Document