scholarly journals Contribution of Each of Four Superantigens to Streptococcus equi-Induced Mitogenicity, Gamma Interferon Synthesis, and Immunity

2010 ◽  
Vol 78 (4) ◽  
pp. 1728-1739 ◽  
Author(s):  
Romain Paillot ◽  
Carl Robinson ◽  
Karen Steward ◽  
Nicola Wright ◽  
Thibaud Jourdan ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Gamma Interferon ◽  
Mitogenic Activity ◽  
Peripheral Blood Mononuclear ◽  
Allelic Replacement ◽  
Neutralizing Capacity ◽  
Streptococcus Equi ◽  
Ifn Γ ◽  
Dose Dependent

ABSTRACT Streptococcus equi is the causative agent of strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation and swelling of the lymph nodes of the head and neck, which can literally strangle the horse to death. S. equi produces four recently acquired phage-associated bacterial superantigens (sAgs; SeeH, SeeI, SeeL, and SeeM) that share homology with the mitogenic toxins of Streptococcus pyogenes. The aim of this study was to characterize the contribution of each of these S. equi sAgs to mitogenic activity in vitro and quantify the sAg-neutralizing capacity of sera from naturally infected horses in order to better understand their role in pathogenicity. Each of the sAgs was successfully cloned, and soluble proteins were produced in Escherichia coli. SeeI, SeeL, and SeeM induced a dose-dependent proliferative response in equine CD4 T lymphocytes and synthesis of gamma interferon (IFN-γ). SeeH did not stimulate equine peripheral blood mononuclear cells (PBMC) but induced proliferation of asinine PBMC. Allelic replacement mutants of S. equi strain 4047 with sequential deletion of the superantigen genes were generated. Deletion of seeI, seeL, and seeM completely abrogated the mitogenic activity and synthesis of IFN-γ, in equine PBMC, of the strain 4047 culture supernatant. Sera from naturally infected convalescent horses had only limited sAg-neutralizing activities. We propose that S. equi sAgs play an important role in S. equi pathogenicity by stimulating an overzealous and inappropriate Th1 response that may interfere with the development of an effective immune response.

scholarly journals Streptococcus pneumoniae Autolysis Prevents Phagocytosis and Production of Phagocyte-Activating Cytokines

2009 ◽  
Vol 77 (9) ◽  
pp. 3826-3837 ◽  
Author(s):  
Anna Martner ◽  
Susann Skovbjerg ◽  
James C. Paton ◽  
Agnes E. Wold
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Interleukin 12 ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Exact Function ◽  
Ifn Γ ◽  
Dose Dependent

ABSTRACT Streptococcus pneumoniae is a major pathogen in humans. The pathogenicity of this organism is related to its many virulence factors, the most important of which is the thick pneumococcal capsule that minimizes phagocytosis. Another virulence-associated trait is the tendency of this bacterium to undergo autolysis in stationary phase through activation of the cell wall-bound amidase LytA, which breaks down peptidoglycan. The exact function of autolysis in pneumococcal pathogenesis is, however, unclear. Here, we show the selective and specific inefficiency of wild-type S. pneumoniae for inducing production of phagocyte-activating cytokines in human peripheral blood mononuclear cells (PBMC). Indeed, clinical pneumococcal strains induced production of 30-fold less tumor necrosis factor (TNF), 15-fold less gamma interferon (IFN-γ), and only negligible amounts of interleukin-12 (IL-12) compared with other closely related Streptococcus species, whereas the levels of induction of IL-6, IL-8, and IL-10 production were similar. If pneumococcal LytA was inactivated by mutation or by culture in a medium containing excess choline, the pneumococci induced production of significantly more TNF, IFN-γ, and IL-12 in PBMC, whereas the production of IL-6, IL-8, and IL-10 was unaffected. Further, adding autolyzed pneumococci to intact bacteria inhibited production of TNF, IFN-γ, and IL-12 in a dose-dependent manner but did not inhibit production of IL-6, IL-8, and IL-10 in response to the intact bacteria. Fragments from autolyzed bacteria inhibited phagocytosis of intact bacteria and reduced the in vitro elimination of pneumococci from human blood. Our results suggest that fragments generated by autolysis of bacteria with reduced viability interfere with phagocyte-mediated elimination of live pneumococci.

scholarly journals Failure of Gamma Interferon but Not Interleukin-10 Expression in Response to Human Papillomavirus Type 11 E6 Protein in Respiratory Papillomatosis

2004 ◽  
Vol 11 (3) ◽  
pp. 538-547 ◽  
Author(s):  
James A. DeVoti ◽  
Bettie M. Steinberg ◽  
David W. Rosenthal ◽  
Lynda Hatam ◽  
Andrea Vambutas ◽  
...  
Keyword(s):  
T Cells ◽  
Human Papillomavirus ◽  
Mononuclear Cells ◽  
Severe Disease ◽  
Interleukin 2 ◽  
Cytokine Expression ◽  
Gamma Interferon ◽  
Peripheral Blood Mononuclear ◽  
Ifn Γ

ABSTRACT Recurrent respiratory papillomatosis (RRP) is a chronic, debilitating disease of the upper airway caused by human papillomavirus type 6 (HPV-6) or HPV-11. We describe responses of peripheral blood mononuclear cells (PBMC) and T cells from RRP patients and controls to the HPV-11 early proteins E6 and E7. PBMC were exposed in vitro to purified E6 or E7 proteins or transduced with fusion proteins containing the first 11 amino acids of the human immunodeficiency virus type 1 protein tat fused to E6 or E7 (tat-E6/tat-E7). TH1-like (interleukin-2 [IL-2], gamma interferon [IFN-γ], IL-12, and IL-18), and TH2-like (IL-4 and IL-10) cytokine mRNAs were identified by reverse transcription-PCR, and IFN-γ and IL-10 cytokine-producing cells were identified by enzyme-linked immunospot assay. These studies show that HPV-11 E6 skews IL-10-IFN-γ expression by patients with RRP toward greater expression of IL-10 than of IFN-γ. In addition, there is a general cytokine hyporesponsiveness to E6 that is more prominent for TH1-like cytokine expression by patients with severe disease. Patients showed persistent IL-10 cytokine expression by the nonadherent fraction of PBMC when challenged with E6 and tat-E6, and, in contrast to controls, both T cells and non-T cells from patients expressed IL-10. However, E7/tat-E7 cytokine responses in patients with RRP were similar to those of the controls. In contrast, E6 inhibited IL-2 and IL-18 mRNA expression that would further contribute to a cytokine microenvironment unfavorable to HPV-specific, T-cell responses that should control persistent HPV infection. In summary, E6 is the dominant inducer of cytokine expression in RRP, and it induces a skewed expression of IL-10 compared to the expression of IFN-γ.

scholarly journals Differences in Gamma Interferon Production In Vitro Predict the Pace of the In Vivo Response to Leishmania amazonensis in Healthy Volunteers

2001 ◽  
Vol 69 (12) ◽  
pp. 7453-7460 ◽  
Author(s):  
M. M. L. Pompeu ◽  
C. Brodskyn ◽  
M. J. Teixeira ◽  
J. Clarêncio ◽  
J. Van Weyenberg ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Interleukin 10 ◽  
Gamma Interferon ◽  
Leishmania Amazonensis ◽  
Cell Mediated Immunity ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Ifn Γ

ABSTRACT The initial encounter of Leishmania cells and cells from the immune system is fundamentally important in the outcome of infection and determines disease development or resistance. We evaluated the anti-Leishmania amazonensis response of naive volunteers by using an in vitro priming (IVP) system and comparing the responses following in vivo vaccination against the same parasite. In vitro stimulation allowed us to distinguish two groups of individuals, those who produced small amounts of gamma interferon (IFN-γ) (n = 16) (low producers) and those who produced large amounts of this cytokine (n = 16) (high producers). IFN-γ production was proportional to tumor necrosis factor alpha and interleukin 10 (IL-10) levels but did not correlate with IL-5 production. Volunteers who produced small amounts of IFN-γ in vitro remained low producers 40 days after vaccination, whereas high producers exhibited increased IFN-γ production. However, 6 months after vaccination, all individuals tested produced similarly high levels of IFN-γ upon stimulation of their peripheral blood mononuclear cells with Leishmania promastigotes, indicating that low in vitro producers respond slowly in vivo to vaccination. In high IFN-γ producers there was an increased frequency of activated CD8+ T cells both in vitro and in vivo compared to the frequency in low producers, and such cells were positive for IFN-γ as determined by intracellular staining. Such findings suggest that IVP responses can be used to predict the pace of postvaccination responses of test volunteers. Although all vaccinated individuals eventually have a potent anti-Leishmania cell-mediated immunity (CMI) response, a delay in mounting the CMI response may influence resistance against leishmaniasis.

scholarly journals Neutralization of Interleukin-10 Significantly Enhances Gamma Interferon Expression in Peripheral Blood by Stimulation with Johnin Purified Protein Derivative and by Infection with Mycobacterium avium subsp. paratuberculosis in Experimentally Infected Cattle with Paratuberculosis

2004 ◽  
Vol 72 (4) ◽  
pp. 2425-2428 ◽  
Author(s):  
Joram J. Buza ◽  
Hirokazu Hikono ◽  
Yasuyuki Mori ◽  
Reiko Nagata ◽  
Sachiyo Hirayama ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Interleukin 10 ◽  
Suppressive Effect ◽  
Gamma Interferon ◽  
Peripheral Blood Mononuclear ◽  
Purified Protein Derivative ◽  
Ifn Γ

ABSTRACT Monoclonal antibody neutralization of interleukin-10 (IL-10) increased Johnin purified protein derivative-induced whole-blood gamma interferon (IFN-γ) secretion 23-fold and also increased IFN-γ secretion ninefold following in vitro Mycobacterium avium subsp. paratuberculosis infection of peripheral blood mononuclear cells. These results demonstrate the suppressive effect of IL-10 on immune responses to M. avium subsp. paratuberculosis infection in cattle.

scholarly journals Modulation of Gamma Interferon Receptor 1 by Mycobacterium tuberculosis: a Potential Immune Response Evasive Mechanism

2007 ◽  
Vol 75 (5) ◽  
pp. 2500-2510 ◽  
Author(s):  
Amit Singhal ◽  
Anand Jaiswal ◽  
Virendra K. Arora ◽  
Hanumanthappa K. Prasad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mrna Expression ◽  
Mononuclear Cells ◽  
Surface Expression ◽  
Gamma Interferon ◽  
Mobility Shift ◽  
Down Regulation ◽  
Peripheral Blood Mononuclear ◽  
Ifn Γ

ABSTRACT Mycobacterium tuberculosis inhibits gamma interferon (IFN-γ)-mediated antimycobacterial action by adopting diverse mechanisms. IFN-γ binds to its receptor, IFN-γR, in order to initiate proper signaling. We have observed reduced surface expression levels of IFN-γ receptor 1 (IFN-γR1) in untreated pulmonary tuberculosis patients compared to those in healthy individuals (P < 0.01). Following antitubercular therapy, the expression of IFN-γR1 was restored in these patients. To delineate the mechanism by which M. tuberculosis modulates IFN-γR1, in vitro experiments were designed, wherein the down modulation of IFN-γR1 surface expression was observed for CD14+ cells in peripheral blood mononuclear cells (PBMCs) cocultured with live M. tuberculosis compared to that for uninfected cells (P < 0.01). No modulation of IFN-γR1 expression was observed for CD14+ cells in PBMCs infected with Mycobacterium smegmatis. A time-dependent decrease in IFN-γR1 mRNA expression was observed for PBMCs infected with M. tuberculosis. Similar down modulation of IFN-γR1 protein and mRNA expression in phorbol myristate acetate-differentiated THP-1 cells (pdTHP-1) by M. tuberculosis was observed (P < 0.01). Using reporter gene analysis of 5′ deletion constructs of the IFN-γR1 gene (IFNGR1) promoter, the decrease in IFN-γR1 mRNA in M. tuberculosis-infected pdTHP-1 cells was shown to be due to the decreased transcription of IFNGR1. By immunoblotting and electrophoretic mobility shift assays, the down regulation of stimulating protein 1 (Sp1) expression and its recruitment on the phorbol ester-responsive element of the IFNGR1 promoter in M. tuberculosis-infected pdTHP-1 cells was observed. This down regulation of Sp1 in pdTHP-1 cells cocultured with M. tuberculosis may be responsible for the down regulation of IFN-γR1 expression, thereby potentially altering its receptivity to IFN-γ.

scholarly journals Identification of Three Novel Superantigen-Encoding Genes in Streptococcus equi subsp. zooepidemicus, szeF, szeN, and szeP

2010 ◽  
Vol 78 (11) ◽  
pp. 4817-4827 ◽  
Author(s):  
Romain Paillot ◽  
Alistair C. Darby ◽  
Carl Robinson ◽  
Nicola L. Wright ◽  
Karen F. Steward ◽  
...  
Keyword(s):  
Horizontal Transfer ◽  
Mononuclear Cells ◽  
Opportunistic Pathogen ◽  
Mitogenic Activity ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Streptococcus Equi ◽  
Factor Alpha ◽  
Encoding Genes

ABSTRACT The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel superantigen-encoding genes. The products of szeF, szeN, and szeP share 59%, 49%, and 34% amino acid sequence identity with SPEH, SPEM, and SPEL, respectively. Recombinant SzeF, SzeN, and SzeP stimulated the proliferation of equine peripheral blood mononuclear cells, and tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) production, in vitro. Although none of these superantigen genes were encoded within functional prophage elements, szeN and szeP were located next to a prophage remnant, suggesting that they were acquired by horizontal transfer. Eighty-one of 165 diverse S. equi subsp. zooepidemicus strains screened, including 7 out of 15 isolates from cases of disease in humans, contained at least one of these new superantigen-encoding genes. The presence of szeN or szeP, but not szeF, was significantly associated with mitogenic activity in the S. equi subsp. zooepidemicus population (P < 0.000001, P < 0.000001, and P = 0.104, respectively). We conclude that horizontal transfer of these novel superantigens from and within the diverse S. equi subsp. zooepidemicus population is likely to have implications for veterinary and human disease.

scholarly journals Protection of BALB/c Mice against Brucella abortus 544 Challenge by Vaccination with Bacterioferritin or P39 Recombinant Proteins with CpG Oligodeoxynucleotides as Adjuvant

2001 ◽  
Vol 69 (8) ◽  
pp. 4816-4822 ◽  
Author(s):  
Ayman Al-Mariri ◽  
Anne Tibor ◽  
Pascal Mertens ◽  
Xavier De Bolle ◽  
Patrick Michel ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Brucella Abortus ◽  
Mononuclear Cells ◽  
Brucella Melitensis ◽  
Cpg Odn ◽  
Peripheral Blood Mononuclear ◽  
Recombinant Antigens ◽  
Cpg Oligodeoxynucleotides ◽  
Ifn Γ

ABSTRACT The P39 and the bacterioferrin (BFR) antigens of Brucella melitensis 16M were previously identified as T dominant antigens able to induce both delayed-type hypersensivity in sensitized guinea pigs and in vitro gamma interferon (IFN-γ) production by peripheral blood mononuclear cells from infected cattle. Here, we analyzed the potential for these antigens to function as a subunitary vaccine against Brucella abortus infection in BALB/c mice, and we characterized the humoral and cellular immune responses induced. Mice were injected with each of the recombinant proteins alone or adjuvanted with either CpG oligodeoxynucleotides (CpG ODN) or non-CpG ODN. Mice immunized with the recombinant antigens with CpG ODN were the only group demonstrating both significant IFN-γ production and T-cell proliferation in response to either Brucella extract or to the respective antigen. The same conclusion holds true for the antibody response, which was only demonstrated in mice immunized with recombinant antigens mixed with CpG ODN. The antibody titers (both immunoglobulin G1 [IgG1] and IgG2a) induced by P39 immunization were higher than the titers induced by BFR (only IgG2a). Using a B. abortus 544 challenge, the level of protection was analyzed and compared to the protection conferred by one immunization with the vaccine strain B19. Immunization with P39 and CpG ODN gave a level of protection comparable to the one conferred by B19 at 4 weeks postchallenge, and the mice were still significantly protected at 8 weeks postchallenge, although to a lesser extent than the B19-vaccinated group. Intriguingly, no protection was detected after BFR vaccination. All other groups did not demonstrate any protection.

scholarly journals Evaluation of Immunostimulatory Activities of Synthetic Mannose-Containing Structures Mimicking the β-(1→2)-Linked Cell Wall Mannans of Candida albicans

2012 ◽  
Vol 19 (11) ◽  
pp. 1889-1893 ◽  
Author(s):  
Kaarina Ranta ◽  
Kaisa Nieminen ◽  
Filip S. Ekholm ◽  
Moniká Poláková ◽  
Mattias U. Roslund ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Mouse Macrophages ◽  
Ifn Γ ◽  
Low Levels ◽  
Necrosis Factor

ABSTRACTImmunostimulatory properties of synthetic structures mimicking the β-(1→2)-linked mannans ofCandida albicanswere evaluatedin vitro. Contrary to earlier observations, tumor necrosis factor (TNF) production was not detected after stimulation with mannotetraose in mouse macrophages. Divalent disaccharide 1,4-bis(α-d-mannopyranosyloxy)butane induced TNF and some molecules induced low levels of gamma interferon (IFN-γ) in human peripheral blood mononuclear cells (PBMC).

scholarly journals A 70-Kilodalton Recombinant Heat Shock Protein ofCandida albicans Is Highly Immunogenic and Enhances Systemic Murine Candidiasis

1998 ◽  
Vol 66 (5) ◽  
pp. 2154-2162 ◽  
Author(s):  
Carla Bromuro ◽  
Roberto La Valle ◽  
Silvia Sandini ◽  
Francesca Urbani ◽  
Clara M. Ausiello ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mononuclear Cells ◽  
Cell Mediated Immunity ◽  
Healthy Human ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Ifn Γ

ABSTRACT The 70-kDa recombinant Candida albicans heat shock protein (CaHsp70) and its 21-kDa C-terminal and 28-kDa N-terminal fragments (CaHsp70-Cter and CaHsp70-Nter, respectively) were studied for their immunogenicity, including proinflammatory cytokine induction in vitro and in vivo, and protection in a murine model of hematogenous candidiasis. The whole protein and its two fragments were strong inducers of both antibody (Ab; immunoglobulin G1 [IgG1] and IgG2b were the prevalent isotypes) and cell-mediated immunity (CMI) responses in mice. CaHsp70 preparations were also recognized as CMI targets by peripheral blood mononuclear cells of healthy human subjects. Inoculation of CaHsp70 preparations into immunized mice induced rapid production of interleukin-6 (IL-6) and tumor necrosis factor alpha, peaking at 2 to 5 h and declining within 24 h. CaHsp70 and CaHsp70-Cter also induced gamma interferon (IFN-γ), IL-12, and IL-10 but not IL-4 production by CD4+ lymphocytes cocultured with splenic accessory cells from nonimmunized mice. In particular, the production of IFN-γ was equal if not superior to that induced in the same cells by whole, heat-inactivated fungal cells or the mitogenic lectin concanavalin A. In immunized mice, however, IL-4 but not IL-12 was produced in addition to IFN-γ upon in vitro stimulation of CD4+ cells with CaHsp70 and CaHsp70-Cter. These animals showed a decreased median survival time compared to nonimmunized mice, and their mortality was strictly associated with organ invasion by fungal hyphae. Their enhanced susceptibility was attributable to the immunization state, as it did not occur in congenitally athymic nude mice, which were unable to raise either Ab or CMI responses to CaHsp70 preparations. Together, our data demonstrate the elevated immunogenicity of CaHsp70, with which, however, no protection against but rather some enhancement of Candida infection seemed to occur in the mouse model used.

Sign in / Sign up

Export Citation Format

Share Document