Induce Gamma Interferon Production Research Articles

Mycobacterium tuberculosis-Induced Gamma Interferon Production by Natural Killer Cells Requires Cross Talk with Antigen-Presenting Cells Involving Toll-Like Receptors 2 and 4 and the Mannose Receptor in Tuberculous Pleurisy

Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tuberculosis infection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-gamma) upon M. tuberculosis stimulation, leading us to investigate the mechanisms and molecules involved in this process. We show that the whole bacterium is the best inducer of IFN-gamma, although a high-molecular-weight fraction of culture filtrate proteins from M. tuberculosis H37Rv and the whole-cell lysate also induce its expression. The mannose receptor seems to mediate the inhibitory effect of mannosylated lipoarabinomannan, and Toll-like receptor 2 and 4 agonists activate NK cells but do not induce IFN-gamma like M. tuberculosis does. Antigen-presenting cells (APC) and NK cells bind M. tuberculosis, and although interleukin-12 is required, it is not sufficient to induce IFN-gamma expression, indicating that NK cell-APC contact takes place. Indeed, major histocompatibility complex class I, adhesion, and costimulatory molecules as well as NK receptors regulate IFN-gamma induction. The signaling pathway is partially inhibited by dexamethasone and sensitive to Ca2+ flux and cyclosporine. Inhibition of p38 and extracellular-regulated kinase mitogen-activated protein kinase pathways reduces the number of IFN-gamma+ NK cells. Phosphorylated p38 (p-p38) is detected in ex vivo PF-NK cells, and M. tuberculosis triggers p-p38 in PF-NK cells at the same time that binding between NK and M. tuberculosis reaches its maximum value. Thus, interplay between M. tuberculosis and NK cells/APC triggering IFN-gamma would be expected to play a beneficial role in tuberculous pleurisy by helping to maintain a type 1 profile.

Highly Efficient Gluten Degradation by Lactobacilli and Fungal Proteases during Food Processing: New Perspectives for Celiac Disease

Presently, the only effective treatment for celiac disease is a life-long gluten-free diet. In this work, we used a new mixture of selected sourdough lactobacilli and fungal proteases to eliminate the toxicity of wheat flour during long-time fermentation. Immunological (R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay [ELISA] and R5 antibody-based Western blot), two-dimensional electrophoresis, and mass spectrometry (matrix-assisted laser desorption ionization-time of flight, strong-cation-exchange-liquid chromatography/capillary liquid chromatography-electrospray ionization-quadrupole-time of flight [SCX-LC/CapLC-ESI-Q-TOF], and high-pressure liquid chromatography-electrospray ionization-ion trap mass spectrometry) analyses were used to determine the gluten concentration. Assays based on the proliferation of peripheral blood mononuclear cells (PBMCs) and gamma interferon production by PBMCs and intestinal T-cell lines (iTCLs) from 12 celiac disease patients were used to determine the protein toxicity of the pepsin-trypsin digests from fermented wheat dough (sourdough). As determined by R5-based sandwich and competitive ELISAs, the residual concentration of gluten in sourdough was 12 ppm. Albumins, globulins, and gliadins were completely hydrolyzed, while ca. 20% of glutenins persisted. Low-molecular-weight epitopes were not detectable by SCX-LC/CapLC-ESI-Q-TOF mass spectrometry and R5-based Western blot analyses. The kinetics of the hydrolysis of the 33-mer by lactobacilli were highly efficient. All proteins extracted from sourdough activated PBMCs and induced gamma interferon production at levels comparable to the negative control. None of the iTCLs demonstrated immunoreactivity towards pepsin-trypsin digests. Bread making was standardized to show the suitability of the detoxified wheat flour. Food processing by selected sourdough lactobacilli and fungal proteases may be considered an efficient approach to eliminate gluten toxicity.

A Recombinant Aspartyl Protease ofCoccidioides posadasiiInduces Protection against Pulmonary Coccidioidomycosis in Mice

Coccidioidomycosis is a respiratory disease of humans caused by the desert soil-borne fungal pathogens Coccidioides spp. Recurrent epidemics of this mycosis in the southwestern United States have contributed significantly to escalated health care costs. Clinical and experimental studies indicate that prior symptomatic coccidioidomycosis induces immunity against subsequent infection, and activation of T cells is essential for containment of the pathogen and its clearance from host tissue. Development of a human vaccine against coccidioidomycosis has focused on recombinant T-cell-reactive antigens which elicit a durable protective immune response against pulmonary infection in mice. In this study we fractionated a protective multicomponent parasitic cell wall extract in an attempt to identify T-cell antigens. Immunoblots of electrophoretic separations of this extract identified patient seroreactive proteins which were subsequently excised from two-dimensional polyacrylamide gel electrophoresis gels, trypsin digested, and sequenced by tandem mass spectrometry. The full-length gene which encodes a dominant protein in the immunoblot was identified using established methods of bioinformatics. The gene was cloned and expressed, and the recombinant protein was shown to stimulate immune T cells in vitro. The deduced protein was predicted to contain epitopes that bind to human major histocompatibility complex class II molecules using a TEPITOPE-based algorithm. Synthetic peptides corresponding to the predicted T-cell epitopes induced gamma interferon production by immune T lymphocytes. The T-cell-reactive antigen, which is homologous to secreted fungal aspartyl proteases, protected mice against pulmonary infection with Coccidioides posadasii. We argue that this immunoproteomic/bioinformatic approach to the identification of candidate vaccines against coccidioidomycosis is both efficient and productive.

Natural killer cells and Helicobacter pylori infection: bacterial antigens and interleukin-12 act synergistically to induce gamma interferon production.

Helicobacter pylori is known to induce a local immune response, which is characterized by activation of lymphocytes and the production of IFN-gamma in the stomach mucosa. Since not only T cells, but also natural killer (NK) cells, are potent producers of gamma interferon (IFN-gamma), we investigated whether NK cells play a role in the immune response to H. pylori infection. Our results showed that NK cells were present in both the gastric and duodenal mucosae but that H. pylori infection did not affect the infiltration of NK cells into the gastrointestinal area. Furthermore, we could show that NK cells could be activated directly by H. pylori antigens, as H. pylori bacteria, as well as lysate from H. pylori, induced the secretion of IFN-gamma by NK cells. NK cells were also activated without direct contact when separated from the bacteria by an epithelial cell layer, indicating that the activation of NK cells by H. pylori can also occur in vivo, in the infected stomach mucosa. Moreover, the production of IFN-gamma by NK cells was greatly enhanced when a small amount of interleukin-12 (IL-12) was added, and this synergistic effect was associated with increased expression of the IL-12 receptor beta2. It was further evident that bacterial lysate alone was sufficient to induce the activation of cytotoxicity-related molecules. In conclusion, we demonstrated that NK cells are present in the gastroduodenal mucosa of humans and that NK cells produce high levels of IFN-gamma when stimulated with a combination of H. pylori antigen and IL-12. We propose that NK cells play an active role in the local immune response to H. pylori infection.

LACK-specific CD4(+) T cells that induce gamma interferon production in patients with localized cutaneous leishmaniasis during an early stage of infection.

The profile of cytokines induced by soluble leishmania antigen (SLA) and the Leishmania homologue of the mammalian receptor for activated C kinase (LACK), a candidate vaccine against leishmaniasis, and the cellular source of the cytokines produced in response to these antigens were analyzed in patients infected with Leishmania guyanensis. Gamma interferon (IFN-gamma) and interleukin-10 (IL-10) were produced in response to LACK. Although LACK-specific CD4(+) cells producing IFN-gamma were isolated only during the early phase of infection (less than 30 days following the onset of infection), cells producing IL-10 in response to LACK were detected in all patients. CD4(+) T cells producing IFN-gamma and IL-13 were produced in response to SLA in all patients. SLA- and LACK-specific T cells are effector memory cells, as they are CD45RA(-) CCR7(-) CD4(+) T cells. CD4(+) T cells producing IFN-gamma are CD62L(-), and CD4(+) T cells producing IL-10 are CD62L(+), indicating that these cells have different tissue-homing capacities. These findings show that SLA and LACK induce both type 1 (IFN-gamma) and type 2 (IL-10 or IL-13) cell responses.

Induction of anti-human immunodeficiency virus type 1 (HIV-1) CD8(+) and CD4(+) T-cell reactivity by dendritic cells loaded with HIV-1 X4-infected apoptotic cells.

T-cell responses to X4 strains of human immunodeficiency virus type 1 (HIV-1) are considered important in controlling progression of HIV-1 infection. We investigated the ability of dendritic cells (DC) and various forms of HIV-1 X4 antigen to induce anti-HIV-1 T-cell responses in autologous peripheral blood mononuclear cells from HIV-1-infected persons. Immature DC loaded with HIV-1 IIIB-infected, autologous, apoptotic CD8(-) cells and matured with CD40 ligand induced gamma interferon production in autologous CD8(+) and CD4(+) T cells. In contrast, mature DC loaded with HIV-1 IIIB-infected, necrotic cells or directly infected with cell-free HIV-1 IIIB were poorly immunogenic. Thus, HIV-1-infected cells undergoing apoptosis serve as a rich source of X4 antigen for CD8(+) and CD4(+) T cells by DC. This may be an important mechanism of HIV-1 immunogenicity and provides a strategy for immunotherapy of HIV-1-infected patients on combination antiretroviral therapy.

Diagnosis of tuberculosis based on the two specific antigens ESAT-6 and CFP10.

Tests based on tuberculin purified protein derivative (PPD) cannot distinguish between tuberculosis infection, Mycobacterium bovis BCG vaccination, or exposure to environmental mycobacteria. The present study investigated the diagnostic potential of two Mycobacterium tuberculosis-specific antigens (ESAT-6 and CFP10) in experimental animals as well as during natural infection in humans and cattle. Both antigens were frequently recognized in vivo and in vitro based on the induction of delayed-type hypersensitivity responses and the ability to induce gamma interferon production by lymphocytes, respectively. The combination of ESAT-6 and CFP10 was found to be highly sensitive and specific for both in vivo and in vitro diagnosis. In humans, the combination had a high sensitivity (73%) and a much higher specificity (93%) than PPD (7%).

Studies on the functional site on staphylococcal enterotoxin A responsible for production of murine gamma interferon.

To identify the functional region(s) associated with induction of gamma interferon on the staphylococcal enterotoxin A molecule, native staphylococcal enterotoxin A molecules and 12 various synthetic peptides corresponding to different regions of entire staphylococcal enterotoxin A were compared to induce gamma interferon production in murine spleen cells. The native staphylococcal enterotoxin A molecule induced gamma interferon production, whereas all of the 12 synthetic peptides did not. Pre-treatment of the murine spleen cells with synthetic peptide A-9 (corresponding to amino acid residues 161-180) significantly inhibited the staphylococcal enterotoxin A-induced gamma interferon production, whereas those with other synthetic peptides did not. When native staphylococcal enterotoxin A was pre-treated with either anti-staphylococcal enterotoxin A serum or anti-peptide sera, anti-staphylococcal enterotoxin A serum and antisera to peptides A-1 (1-20), A-7 (121-140), A-8 (141-160), A-9 (161-180) and A-10 (181-200) inhibited the staphylococcal enterotoxin A-induced gamma interferon production. From these findings, the amino acid residues 161-180 on the staphylococcal enterotoxin A molecule may be an essential region for murine gamma interferon production. Furthermore, the neutralizing epitopes may be also located on regions of amino acid residues 1-20, 121-140, 141-160 and 181-200 on the staphylococcal enterotoxin A molecule.

COMPARISON OF INTERLEUKIN 2 AND GAMMA-INTERFERON PRODUCTION BY PERIPHERAL BLOOD MONONUCLEAR CELLS IN RESPONSE TO CYTOMEGALOVIRUS AFTER MARROW TRANSPLANTATION

Forty-five patients were prospectively studied during the first 100 days after allogeneic marrow transplant to determine the relationship between cytomegalovirus-specific gamma-interferon and interleukin 2 production by peripheral blood mononuclear cells and CMV infection. IL-2 production was significantly lower than normal throughout the study period (P = 0.0001). In contrast, mitogen-induced gamma-interferon production was in the normal range by days 41-60 while CMV antigen induced gamma-interferon production by PBMC was normal by 81-100 days after transplant. Antibody- and complement-depletion studies showed that T4 helper cells were capable of gamma-interferon production in response to CMV antigen despite deficient IL-2 production. Neither gamma-interferon nor IL-2 production distinguished CMV-infected from uninfected patients. However, CMV-infected patients had significantly more T8 cytotoxic/suppressor cells than did uninfected patients by 81-100 days after transplant (P = 0.001). In vitro addition of IL-2 significantly increased gamma-interferon production by PBMC from patients with reduced production, suggesting that decreased gamma-interferon production may be related to deficient IL-2 production. Deficiencies in both CMV-specific IL-2 and gamma-interferon production may contribute to the high frequency and severity of CMV infection after marrow transplantation.

Are automated blood pressure devices useful for mass, high-density hypertension screening?: D. M. Berkson, Chicago Department of Health, Richard J. Daley Center, Chicago, Illinois 60602; D. Mikes; H. Stanton; I. Whipple; D. Ausbrook; H. Muriel

To identify the functional region(s) associated with induction of gamma interferon on the staphylococcal enterotoxin A molecule, native staphylococcal enterotoxin A molecules and 12 various synthetic peptides corresponding to different regions of entire staphylococcal enterotoxin A were compared to induce gamma interferon production in murine spleen cells. The native staphylococcal enterotoxin A molecule induced gamma interferon production, whereas all of the 12 synthetic peptides did not. Pre-treatment of the murine spleen cells with synthetic peptide A-9 (corresponding to amino acid residues 161–180) significantly inhibited the staphylococcal enterotoxin A-induced gamma interferon production, whereas those with other synthetic peptides did not. When native staphylococcal enterotoxin A was pre-treated with either anti-staphylococcal enterotoxin A serum or anti-peptide sera, anti-staphylococcal enterotoxin A serum and antisera to peptides A-1 (1–20), A-7 (121–140), A-8 (141–160), A-9 (161–180) and A-10 (181–200) inhibited the staphylococcal enterotoxin A-induced gamma interferon production. From these findings, the amino acid residues 161–180 on the staphylococcal enterotoxin A molecule may be an essential region for murine gamma interferon production. Furthermore, the neutralizing epitopes may be also located on regions of amino acid residues 1–20, 121–140, 141–160 and 181–200 on the staphylococcal enterotoxin A molecule.

Identifying modifiable risk factors as a step toward high blood pressure control: Benjamin F. Banahan III, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, Mississippi; Thomas R. Sharpe

To identify the functional region(s) associated with induction of gamma interferon on the staphylococcal enterotoxin A molecule, native staphylococcal enterotoxin A molecules and 12 various synthetic peptides corresponding to different regions of entire staphylococcal enterotoxin A were compared to induce gamma interferon production in murine spleen cells. The native staphylococcal enterotoxin A molecule induced gamma interferon production, whereas all of the 12 synthetic peptides did not. Pre-treatment of the murine spleen cells with synthetic peptide A-9 (corresponding to amino acid residues 161–180) significantly inhibited the staphylococcal enterotoxin A-induced gamma interferon production, whereas those with other synthetic peptides did not. When native staphylococcal enterotoxin A was pre-treated with either anti-staphylococcal enterotoxin A serum or anti-peptide sera, anti-staphylococcal enterotoxin A serum and antisera to peptides A-1 (1–20), A-7 (121–140), A-8 (141–160), A-9 (161–180) and A-10 (181–200) inhibited the staphylococcal enterotoxin A-induced gamma interferon production. From these findings, the amino acid residues 161–180 on the staphylococcal enterotoxin A molecule may be an essential region for murine gamma interferon production. Furthermore, the neutralizing epitopes may be also located on regions of amino acid residues 1–20, 121–140, 141–160 and 181–200 on the staphylococcal enterotoxin A molecule.