scholarly journals Protective and Pathological Functions of CD8+T Cells in Leishmania braziliensis Infection

2014 ◽  
Vol 83 (3) ◽  
pp. 898-906 ◽  
Author(s):  
Thiago Marconi Cardoso ◽  
Álvaro Machado ◽  
Diego Luiz Costa ◽  
Lucas P. Carvalho ◽  
Adriano Queiroz ◽  
...  
Keyword(s):  
T Cells ◽  
Mononuclear Cells ◽  
Granzyme B ◽  
Delayed Type Hypersensitivity ◽  
Leishmania Braziliensis ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Factor Alpha ◽  
Ifn Γ

Cutaneous leishmaniasis (CL) caused byLeishmania braziliensisis characterized by a strong Th1 response that leads to skin lesion development. In areas whereL. braziliensistransmission is endemic, up to 15% of healthy subjects have tested positive for delayed-type hypersensitivity to soluble leishmania antigen (SLA) and are considered to have subclinical (SC) infection. SC subjects produce less gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) than do CL patients, but they are able to control the infection. The aim of this study was to characterized the role of CD8+T cells in SC infection and in CL. Peripheral blood mononuclear cells (PBMC) were stimulated with SLA to determine the frequencies of CD4+IFN-γ+and CD8+IFN-γ+T cells. Monocytes from PBMC were infected withL. braziliensisand cocultured with CD8+T cells, and the frequencies of infected monocytes and levels of cytotoxicity markers, target cell apoptosis, and granzyme B were determined. The frequency of CD8+IFN-γ+cells after SLA stimulation was higher for SC individuals than for CL patients. The frequency of infected monocytes in SC cells was lower than that in CL cells. CL CD8+T cells induced more apoptosis of infected monocytes than did SC CD8+T cells. Granzyme B production in CD8+T cells was higher in CL than in SC cells. While the use of a granzyme B inhibitor decreased the number of apoptotic cells in the CL group, the use of z-VAD-FMK had no effect on the frequency of these cells. These results suggest that CL CD8+T cells are more cytotoxic and may be involved in pathology.

scholarly journals The Secreted Protein Rv1860 of Mycobacterium tuberculosis Stimulates Human Polyfunctional CD8+T Cells

2016 ◽  
Vol 23 (4) ◽  
pp. 282-293 ◽  
Author(s):  
Vijaya Satchidanandam ◽  
Naveen Kumar ◽  
Sunetra Biswas ◽  
Rajiv S. Jumani ◽  
Chandni Jain ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Mononuclear Cells ◽  
Interleukin 10 ◽  
T Cell Response ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Latent Tb Infection

ABSTRACTWe previously reported that Rv1860 protein fromMycobacterium tuberculosisstimulated CD4+and CD8+T cells secreting gamma interferon (IFN-γ) in healthy purified protein derivative (PPD)-positive individuals and protected guinea pigs immunized with a DNA vaccine and a recombinant poxvirus expressing Rv1860 from a challenge with virulentM. tuberculosis. We now show Rv1860-specific polyfunctional T (PFT) cell responses in the blood of healthy latentlyM. tuberculosis-infected individuals dominated by CD8+T cells, using a panel of 32 overlapping peptides spanning the length of Rv1860. Multiple subsets of CD8+PFT cells were significantly more numerous in healthy latently infected volunteers (HV) than in tuberculosis (TB) patients (PAT). The responses of peripheral blood mononuclear cells (PBMC) from PAT to the peptides of Rv1860 were dominated by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) secretions, the former coming predominantly from non-T cell sources. Notably, the pattern of the T cell response to Rv1860 was distinctly different from those of the widely studiedM. tuberculosisantigens ESAT-6, CFP-10, Ag85A, and Ag85B, which elicited CD4+T cell-dominated responses as previously reported in other cohorts. We further identified a peptide spanning amino acids 21 to 39 of the Rv1860 protein with the potential to distinguish latent TB infection from disease due to its ability to stimulate differential cytokine signatures in HV and PAT. We suggest that a TB vaccine carrying these and other CD8+T-cell-stimulating antigens has the potential to prevent progression of latentM. tuberculosisinfection to TB disease.

scholarly journals Prediction and Validation of Immunogenic Domains of Pneumococcal Proteins Recognized by Human CD4+T Cells

2019 ◽  
Vol 87 (6) ◽  
Author(s):  
Martijn D. B. van de Garde ◽  
Els van Westen ◽  
Martien C. M. Poelen ◽  
Nynke Y. Rots ◽  
Cécile A. C. M. van Els
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
Cell Clone ◽  
Bioinformatics Tool ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
T Cell Clone ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACTCD4+T-cell mechanisms are implied in protection against pneumococcal colonization; however, their target antigens and function are not well defined. In contrast to high-throughput protein arrays for serology, basic antigen tools for CD4+T-cell studies are lacking. Here, we evaluate the potential of a bioinformatics tool forin silicoprediction of immunogenicity as a method to reveal domains of pneumococcal proteins targeted by human CD4+T cells. For 100 pneumococcal proteins, CD4+T-cell immunogenicity was predicted based on HLA-DRB1 binding motifs. For 20 potentially CD4+T-cell immunogenic proteins, epitope regions were verified by testing synthetic peptides in T-cell assays using peripheral blood mononuclear cells from healthy adults. Peptide pools of 19 out of 20 proteins evoked T-cell responses. The most frequent responses (detectable in ≥20% of donors tested) were found to SP_0117 (PspA), SP_0468 (putative sortase), SP_0546 (BlpZ), SP_1650 (PsaA), SP_1923 (Ply), SP_2048 (conserved hypothetical protein), SP_2216 (PscB), and SPR_0907 (PhtD). Responding donors had diverging recognition patterns and profiles of signature cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], interleukin-13 [IL-13], and/or IL-17A) against single-epitope regions. Natural HLA-DR-restricted presentation and recognition of a predicted SP_1923-derived epitope were validated through the isolation of a CD4+T-cell clone producing IFN-γ, TNF-α, and IL-17A in response to the synthetic peptide, whole protein, and heat-inactivated pneumococcus. This proof of principle for a bioinformatics tool to identify pneumococcal protein epitopes targeted by human CD4+T cells provides a peptide-based strategy to study cell-mediated immune mechanisms for the pneumococcal proteome, advancing the development of immunomonitoring assays and targeted vaccine approaches.

scholarly journals Immunization with Brucella VirB Proteins Reduces Organ Colonization in Mice through a Th1-Type Immune Response and Elicits a Similar Immune Response in Dogs

2014 ◽  
Vol 22 (3) ◽  
pp. 274-281 ◽  
Author(s):  
Cora N. Pollak ◽  
María Magdalena Wanke ◽  
Silvia M. Estein ◽  
M. Victoria Delpino ◽  
Norma E. Monachesi ◽  
...  
Keyword(s):  
Immune Response ◽  
Mononuclear Cells ◽  
Interleukin 4 ◽  
Delayed Type Hypersensitivity ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Type Iv ◽  
Ifn Γ ◽  
Organ Colonization

ABSTRACTVirB proteins fromBrucellaspp. constitute the type IV secretion system, a key virulence factor mediating the intracellular survival of these bacteria. Here, we assessed whether a Th1-type immune response against VirB proteins may protect mice fromBrucellainfection and whether this response can be induced in the dog, a natural host forBrucella. Splenocytes from mice immunized with VirB7 or VirB9 responded to their respective antigens with significant and specific production of gamma interferon (IFN-γ), whereas interleukin-4 (IL-4) was not detected. Thirty days after an intraperitoneal challenge with liveBrucella abortus, the spleen load of bacteria was almost 1 log lower in mice immunized with VirB proteins than in unvaccinated animals. As colonization reduction seemed to correlate with a Th1-type immune response against VirB proteins, we decided to assess whether such a response could be elicited in the dog. Peripheral blood mononuclear cells (PBMCs) from dogs immunized with VirB proteins (three subcutaneous doses in QuilA adjuvant) produced significantly higher levels of IFN-γ than cells from control animals uponin vitrostimulation with VirB proteins. A skin test to assess specific delayed-type hypersensitivity was positive in 4 out of 5 dogs immunized with either VirB7 or VirB9. As both proteins are predicted to locate in the outer membrane ofBrucellaorganisms, the ability of anti-VirB antibodies to mediate complement-dependent bacteriolysis ofB. caniswas assessedin vitro. Sera from dogs immunized with either VirB7 or VirB9, but not from those receiving phosphate-buffered saline (PBS), produced significant bacteriolysis. These results suggest that VirB-specific responses that reduce organ colonization byBrucellain mice can be also elicited in dogs.

scholarly journals New Verapamil Analogs Inhibit Intracellular Mycobacteria without Affecting the Functions of Mycobacterium-Specific T Cells

2015 ◽  
Vol 60 (3) ◽  
pp. 1216-1225 ◽  
Author(s):  
Getahun Abate ◽  
Peter G. Ruminiski ◽  
Malkeet Kumar ◽  
Kawaljit Singh ◽  
Fahreta Hamzabegovic ◽  
...  
Keyword(s):  
T Cells ◽  
Macrophage Activation ◽  
Mononuclear Cells ◽  
Efflux Pump ◽  
Interleukin 1 ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Whole Cell Lysate ◽  
Autophagy Induction

There is a growing interest in repurposing mycobacterial efflux pump inhibitors, such as verapamil, for tuberculosis (TB) treatment. To aid in the design of better analogs, we studied the effects of verapamil on macrophages andMycobacterium tuberculosis-specific T cells. Macrophage activation was evaluated by measuring levels of nitric oxide, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and gamma interferon (IFN-γ). Since verapamil is a known autophagy inducer, the roles of autophagy induction in the antimycobacterial activities of verapamil and norverapamil were studied using bone marrow-derived macrophages from ATG5flox/flox(control) and ATG5flox/floxLyz-Cre mice. Our results showed that despite the well-recognized effects of verapamil on calcium channels and autophagy, its action on intracellularM. tuberculosisdoes not involve macrophage activation or autophagy induction. Next, the effects of verapamil and norverapamil onM. tuberculosis-specific T cells were assessed using flow cytometry following the stimulation of peripheral blood mononuclear cells from TB-skin-test-positive donors withM. tuberculosiswhole-cell lysate for 7 days in the presence or absence of drugs. We found that verapamil and norverapamil inhibit the expansion ofM. tuberculosis-specific T cells. Additionally, three new verapamil analogs were found to inhibit intracellularMycobacterium bovisBCG, and one of the three analogs (KSV21) inhibited intracellularM. tuberculosisreplication at concentrations that did not inhibitM. tuberculosis-specific T cell expansion. KSV21 also inhibited mycobacterial efflux pumps to the same degree as verapamil. More interestingly, the new analog enhances the inhibitory activities of isoniazid and rifampin on intracellularM. tuberculosis. In conclusion, KSV21 is a promising verapamil analog on which to base structure-activity relationship studies aimed at identifying more effective analogs.

scholarly journals Interleukin-12 Enhances Antifungal Activity of Human Mononuclear Phagocytes against Aspergillus fumigatus: Implications for a Gamma Interferon-Independent Pathway

1999 ◽  
Vol 67 (6) ◽  
pp. 3047-3050 ◽  
Author(s):  
Emmanuel Roilides ◽  
Sevasti Tsaparidou ◽  
Isaac Kadiltsoglou ◽  
Tin Sein ◽  
Thomas J. Walsh
Keyword(s):  
Aspergillus Fumigatus ◽  
Mononuclear Cells ◽  
Gamma Interferon ◽  
Mononuclear Phagocytes ◽  
Interleukin 12 ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT The potential of recombinant human interleukin-12 (IL-12) to enhance the capacity of human monocytes (MNC) to elicit an oxidative burst and damage hyphae of Aspergillus fumigatus was investigated. Incubation of peripheral blood mononuclear cells (PBMC) from healthy adults with 10 to 100 ng of IL-12/ml at 37°C for 2 to 3 days enhanced the production of superoxide anion (O2 −) in response to phorbol myristate acetate (PMA) (P = 0.04) and unopsonized A. fumigatus hyphae (P = 0.03) and further enhanced hyphal damage (P = 0.009). Anti-gamma interferon (anti-IFN-γ) blocked secretion of IFN-γ by IL-12-treated PBMC but did not inhibit IL-12-induced O2 − production by these cells in response to PMA. In addition, IL-12-treated elutriated MNC secreted no IFN-γ or tumor necrosis factor alpha but exhibited enhanced O2 − production compared to controls (P = 0.013). These findings demonstrate that IL-12 augments oxidative antifungal activities of MNC via an IFN-γ-independent route, suggesting a novel pathway of IL-12 action in antifungal defense.

scholarly journals The Predominant CD4+ Th1 Cytokine Elicited to Chlamydia trachomatis Infection in Women Is Tumor Necrosis Factor Alpha and Not Interferon Gamma

2017 ◽  
Vol 24 (4) ◽  
Author(s):  
Stephen J. Jordan ◽  
Kanupriya Gupta ◽  
Brian M. O. Ogendi ◽  
Rakesh K. Bakshi ◽  
Richa Kapil ◽  
...  
Keyword(s):  
T Cells ◽  
Chlamydia Trachomatis ◽  
Tumor Necrosis ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Th1 Cytokine ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and can cause significant reproductive morbidity in women. There is insufficient knowledge of C. trachomatis-specific immune responses in humans, which could be important in guiding vaccine development efforts. In contrast, murine models have clearly demonstrated the essential role of T helper type 1 (Th1) cells, especially interferon gamma (IFN-γ)-producing CD4+ T cells, in protective immunity to chlamydia. To determine the frequency and magnitude of Th1 cytokine responses elicited to C. trachomatis infection in humans, we stimulated peripheral blood mononuclear cells from 90 chlamydia-infected women with C. trachomatis elementary bodies, Pgp3, and major outer membrane protein and measured IFN-γ-, tumor necrosis factor alpha (TNF-α)-, and interleukin-2 (IL-2)-producing CD4+ and CD8+ T-cell responses using intracellular cytokine staining. The majority of chlamydia-infected women elicited CD4+ TNF-α responses, with frequency and magnitude varying significantly depending on the C. trachomatis antigen used. CD4+ IFN-γ and IL-2 responses occurred infrequently, as did production of any of the three cytokines by CD8+ T cells. About one-third of TNF-α-producing CD4+ T cells coproduced IFN-γ or IL-2. In summary, the predominant Th1 cytokine response elicited to C. trachomatis infection in women was a CD4+ TNF-α response, not CD4+ IFN-γ, and a subset of the CD4+ TNF-α-positive cells produced a second Th1 cytokine.

scholarly journals Reactivation of Latent Human Cytomegalovirus in CD14+ Monocytes Is Differentiation Dependent

2001 ◽  
Vol 75 (16) ◽  
pp. 7543-7554 ◽  
Author(s):  
Cecilia Söderberg-Nauclér ◽  
Daniel N. Streblow ◽  
Kenneth N. Fish ◽  
Justine Allan-Yorke ◽  
Patricia P. Smith ◽  
...  
Keyword(s):  
T Cells ◽  
Human Cytomegalovirus ◽  
Mononuclear Cells ◽  
Interleukin 1 ◽  
Hla Class I ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Significant Difference ◽  
Hcmv Replication ◽  
Ifn Γ

ABSTRACT We have previously demonstrated reactivation of latent human cytomegalovirus (HCMV) in myeloid lineage cells obtained from healthy donors. Virus was obtained from allogenically stimulated monocyte-derived macrophages (Allo-MDM), but not from macrophages differentiated by mitogenic stimulation (ConA-MDM). In the present study, the cellular and cytokine components essential for HCMV replication and reactivation were examined in Allo-MDM. The importance of both CD4+ and CD8+ T cells in the generation of HCMV-permissive Allo-MDM was demonstrated by negative selection or blocking experiments using antibodies directed against both HLA class I and HLA class II molecules. Interestingly, contact of monocytes with CD4 or CD8 T cells was not essential for reactivation of HCMV, since virus was observed in macrophages derived from CD14+monocytes stimulated by supernatants produced by allogeneic stimulation of peripheral blood mononuclear cells. Examination of the cytokines produced in Allo-MDM and ConA-MDM cultures indicated a significant difference in the kinetics of production and quantity of these factors. Further examination of the cytokines essential for the generation of HCMV-permissive Allo-MDM identified gamma interferon (IFN-γ) but not interleukin-1 or -2, tumor necrosis factor alpha, or granulocyte-macrophage colony-stimulating factor as critical components in the generation of these macrophages. In addition, although IFN-γ was crucial for reactivation of latent HCMV, addition of IFN-γ to unstimulated macrophage cultures was insufficient to reactivate virus. Thus, this study characterizes two distinct monocyte-derived cell types which can be distinguished by their ability to reactivate and support HCMV replication and identifies the critical importance of IFN-γ in the reactivation of HCMV.

scholarly journals An Enzyme-Linked Immunosorbent Spot Assay MeasuringBorrelia burgdorferiB31-Specific Interferon Gamma-Secreting T Cells Cannot Discriminate Active Lyme Neuroborreliosis from Past Lyme Borreliosis: a Prospective Study in the Netherlands

2018 ◽  
Vol 56 (4) ◽  
Author(s):  
T. van Gorkom ◽  
S. U. C. Sankatsing ◽  
W. Voet ◽  
D. M. Ismail ◽  
R. H. Muilwijk ◽  
...  
Keyword(s):  
T Cells ◽  
Interferon Gamma ◽  
Lyme Borreliosis ◽  
Elispot Assay ◽  
Mononuclear Cells ◽  
Lyme Neuroborreliosis ◽  
Healthy Individuals ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Ifn Γ

ABSTRACTTwo-tier serology testing is most frequently used for the diagnosis of Lyme borreliosis (LB); however, a positive result is no proof of active disease. To establish a diagnosis of active LB, better diagnostics are needed. Tests investigating the cellular immune system are available, but studies evaluating the utility of these tests on well-defined patient populations are lacking. Therefore, we investigated the utility of an enzyme-linked immunosorbent spot (ELISpot) assay to diagnose active Lyme neuroborreliosis. Peripheral blood mononuclear cells (PBMCs) of various study groups were stimulated by usingBorrelia burgdorferistrain B31 and various recombinant antigens, and subsequently, the number ofBorrelia-specific interferon gamma (IFN-γ)-secreting T cells was measured. We included 33 active and 37 treated Lyme neuroborreliosis patients, 28 healthy individuals treated for an early manifestation of LB in the past, and 145 untreated healthy individuals. The median numbers ofB. burgdorferiB31-specific IFN-γ-secreting T cells/2.5 × 105PBMCs did not differ between active Lyme neuroborreliosis patients (6.0; interquartile range [IQR], 0.5 to 14.0), treated Lyme neuroborreliosis patients (4.5; IQR, 2.0 to 18.6), and treated healthy individuals (7.4; IQR, 2.3 to 14.9) (P= 1.000); however, the median number ofB. burgdorferiB31-specific IFN-γ-secreting T cells/2.5 × 105PBMCs among untreated healthy individuals was lower (2.0; IQR, 0.5 to 3.9) (P≤ 0.016). We conclude that theBorreliaELISpot assay, measuring the number ofB. burgdorferiB31-specific IFN-γ-secreting T cells/2.5 × 105PBMCs, correlates with exposure to theBorreliabacterium but cannot be used for the diagnosis of active Lyme neuroborreliosis.

scholarly journals Lipopolysaccharides prime whole human blood and isolated neutrophils for the increased synthesis of 5-lipoxygenase products by enhancing arachidonic acid availability: involvement of the CD14 antigen.

1993 ◽  
Vol 178 (4) ◽  
pp. 1347-1355 ◽  
Author(s):  
M E Surette ◽  
R Palmantier ◽  
J Gosselin ◽  
P Borgeat
Keyword(s):  
Arachidonic Acid ◽  
Mononuclear Cells ◽  
Leukotriene B4 ◽  
Eicosatetraenoic Acid ◽  
Tnf Alpha ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Priming Activity

Stimulation of heparinized blood with 1 microM formyl-methionyl-leucyl-phenylalanine (FMLP) resulted in the formation of < 30 pmol/ml plasma of 5-lipoxygenase (5-LO) products. The preincubation of blood with 1 microgram/ml of lipopolysaccharide (LPS) (Escherichia coli 0111-B4) for 30 min before stimulation with FMLP resulted in the accumulation of 250-300 pmol of 5-LO products per ml plasma. The major products detected were leukotriene B4 and (5S)-hydroxy-6,8,11,14-eicosatetraenoic acid which were produced in equivalent amounts. The priming activity was detectable with as little as 1-10 ng LPS per ml blood and was optimal using 1-10 micrograms LPS/ml blood. The priming for 5-LO product synthesis was optimal after 20-30 min of preincubation with LPS and declined at preincubation times > 30 min. The priming effect of LPS was also observed using the complement fragment C5a or interleukin 8 as agonists. Polymorphonuclear leukocytes (PMN) and peripheral blood mononuclear cells accounted for 80 and 20% of the synthesis of 5-LO products, respectively. The ability of LPS to prime isolated PMN was dependent on the presence of plasma and was inhibited by the anti-CD14 antibody IOM2, indicating a CD14-dependent priming mechanism. The priming of whole blood with tumor necrosis factor alpha (TNF-alpha) and LPS was additive and the presence of mononuclear cells did not enhance the ability of LPS to prime PMN, indicating that the priming activity of LPS is independent of LPS-induced TNF-alpha synthesis. The mechanism by which LPS enhance 5-LO product synthesis in PMN was investigated. Treatment of PMN with LPS strongly enhanced the release of arachidonic acid after stimulation with FMLP. The release of arachidonic acid was optimal 2-3 min after stimulation with FMLP, attaining levels 5-15-fold greater than those observed in unprimed cells stimulated with FMLP. These results demonstrate that LPS dramatically increases the ability of blood to generate 5-LO products, and support the putative role of leukotrienes in pathological states involving LPS.

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