scholarly journals Cytokine Responses to Plasmodium falciparumLiver-Stage Antigen 1 Vary in Rainy and Dry Seasons in Highland Kenya

2000 ◽  
Vol 68 (9) ◽  
pp. 5198-5204 ◽  
Author(s):  
C. C. John ◽  
P. O. Sumba ◽  
J. H. Ouma ◽  
B. L. Nahlen ◽  
C. L. King ◽  
...  

ABSTRACT Seasonal epidemics of malaria occur in highland areas of western Kenya where transmission intensity varies according to rainfall. This study describes the seasonal changes in cytokine responses toPlasmodium falciparum liver-stage antigen 1 (LSA-1) by children (≤17 years old) and adults (≥18 years old) living in such a highland area. Fourteen- to 24-mer peptides corresponding to the N- and C-terminal nonrepeat regions of LSA-1 stimulated production of interleukin-5 (IL-5), interleukin-10 (IL-10), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) by peripheral blood mononuclear cells (PBMC) from 17 to 73% of individuals in both age groups in both seasons. IL-10 and TNF-α responses were more frequent during the high-transmission, rainy season than during the low-transmission, dry season (73 and 67% versus 17 and 25% response rates, respectively). In contrast, there was no seasonal change in the proportion of LSA-1-driven IFN-γ and IL-5 responses. Children produced less IFN-γ than adults, but IL-5, IL-10, and TNF-α levels were similar for both age groups. Depletion of CD8+ cells from PBMC decreased IFN-γ but increased IL-10 production. Individuals with LSA-1-stimulated IL-10 responses in the dry season were less likely to become reinfected in the subsequent rainy season than those without IL-10 responses (25% versus 49%;P = 0.083). These data support the notion that maintenance of LSA-1-driven IL-10 and TNF-α responses requires repeated and sustained exposure to liver-stage P. falciparum. In contrast, IFN-γ responses increase slowly with age but persist once acquired. CD8+ T cells are the major source of IFN-γ but may suppress production or secretion of IL-10.

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

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.


1999 ◽  
Vol 6 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Teresa Krakauer ◽  
Bradley G. Stiles

ABSTRACT Tumor necrosis factor alpha (TNF-α) is a critical cytokine that mediates the toxic effects of bacterial superantigens like staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin 1 (TSST-1). Pentoxifylline, an anti-inflammatory agent that inhibits endotoxemia and lipopolysaccharide (LPS)-induced release of TNF-α, was tested for its ability to inhibit SEB- and TSST-1-induced activation of human peripheral blood mononuclear cells (PBMCs) in vitro and toxin-mediated shock in mice. Stimulation of PBMCs by SEB or TSST-1 was effectively blocked by pentoxifylline (10 mM), as evidenced by the inhibition of TNF-α, interleukin 1β (IL-1β), gamma interferon (IFN-γ), and T-cell proliferation. The levels of TNF-α, IL-1α, and IFN-γ in serum after an SEB or TSST-1 injection were significantly lower in mice given pentoxifylline (5.5 mg/animal) versus control mice. Additionally, pentoxifylline diminished the lethal effects and temperature fluctuations elicited by SEB and TSST-1. Thus, in addition to treating endotoxemias, the cumulative in vitro and in vivo data suggest that pentoxifylline may also be useful in abrogating the ill effects of staphylococcal enterotoxins and TSST-1.


2014 ◽  
Vol 82 (9) ◽  
pp. 3775-3782 ◽  
Author(s):  
Lyticia A. Ochola ◽  
Cyrus Ayieko ◽  
Lily Kisia ◽  
Ng'wena G. Magak ◽  
Estela Shabani ◽  
...  

ABSTRACTIndividuals naturally exposed toPlasmodium falciparumlose clinical immunity after a prolonged lack of exposure.P. falciparumantigen-specific cytokine responses have been associated with protection from clinical malaria, but the longevity ofP. falciparumantigen-specific cytokine responses in the absence of exposure is not well characterized. A highland area of Kenya with low and unstable malaria transmission provided an opportunity to study this question. The levels of antigen-specific cytokines and chemokines associated in previous studies with protection from clinical malaria (gamma interferon [IFN-γ], interleukin-10 [IL-10], and tumor necrosis factor alpha [TNF-α]), with increased risk of clinical malaria (IL-6), or with pathogenesis of severe disease in malaria (IL-5 and RANTES) were assessed by cytometric bead assay in April 2008, October 2008, and April 2009 in 100 children and adults. During the 1-year study period, none had an episode of clinicalP. falciparummalaria. Two patterns of cytokine responses emerged, with some variation by antigen: a decrease at 6 months (IFN-γ and IL-5) or at both 6 and 12 months (IL-10 and TNF-α) or no change over time (IL-6 and RANTES). These findings document thatP. falciparumantigen-specific cytokine responses associated in prior studies with protection from malaria (IFN-γ, TNF-α, and IL-10) decrease significantly in the absence ofP. falciparumexposure, whereas those associated with increased risk of malaria (IL-6) do not. The study findings provide a strong rationale for future studies of antigen-specific IFN-γ, TNF-α, and IL-10 responses as biomarkers of increased population-level susceptibility to malaria after prolonged lack ofP. falciparumexposure.


1998 ◽  
Vol 66 (5) ◽  
pp. 2154-2162 ◽  
Author(s):  
Carla Bromuro ◽  
Roberto La Valle ◽  
Silvia Sandini ◽  
Francesca Urbani ◽  
Clara M. Ausiello ◽  
...  

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.


2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Patricia F. Herkert ◽  
Jessica C. dos Santos ◽  
Ferry Hagen ◽  
Fatima Ribeiro-Dias ◽  
Flávio Queiroz-Telles ◽  
...  

ABSTRACT Cryptococcal species vary in capsule and cell size, thermotolerance, geographic distribution, and affected populations. Cryptococcus gattii sensu stricto and C. deuterogattii affect mainly immunocompetent hosts; however, C. bacillisporus , C. decagattii , and C. tetragattii cause infections mainly in immunocompromised hosts. This study aimed to compare the capacities of different species of the C. gattii species complex to induce cytokines and antimicrobial molecules in human peripheral blood mononuclear cells (PBMCs). Cryptococcus bacillisporus and C. deuterogattii induced the lowest levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 among the five species of the C. gattii complex. Cryptococcus deuterogattii induced higher levels of IL-22 than those induced by C. tetragattii and the environmental species C. flavescens . In addition, C. bacillisporus and C. gattii sensu stricto proliferated inside human monocyte-derived macrophages after 24 h of infection. All Cryptococcus species were able to generate reactive oxygen species (ROS) in human PBMCs, with C. bacillisporus and C. deuterogattii being more efficient than the other species. In conclusion, C. bacillisporus and C. deuterogattii induce lower levels of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and higher ROS levels than those induced by the other species. Species of the Cryptococcus gattii complex have different abilities to induce cytokine and ROS production by human PBMCs.


2007 ◽  
Vol 81 (11) ◽  
pp. 5460-5471 ◽  
Author(s):  
J. William Critchfield ◽  
Donna Lemongello ◽  
Digna H. Walker ◽  
Juan C. Garcia ◽  
David M. Asmuth ◽  
...  

ABSTRACT The intestinal tract is a lymphocyte-rich site that undergoes severe depletion of memory CD4+ T cells within days of simian immunodeficiency virus or human immunodeficiency virus type 1 (HIV-1) infection. An ensuing influx of virus-specific CD8+ T cells, which persist throughout the chronic phase of infection, has also been documented in the gastrointestinal tract. However, little is known of the functionality of these effector cells or their relationship to the disease course. In this study, we measured CD8+ T-cell responses to HIV-1 peptides in paired rectal and blood samples from chronically infected patients. In both blood and rectum, there was an immunodominant CD8+ T-cell response to HIV Gag compared to Pol and Env (P < 0.01). In contrast, cytomegalovirus pp65 peptides elicited gamma interferon (IFN-γ) secretion strongly in peripheral blood mononuclear cells (PBMC) but weakly in rectal CD8+ T cells (P = 0.015). Upon stimulation with HIV peptides, CD8+ T cells from both sites were capable of mounting complex responses including degranulation (CD107 expression) and IFN-γ and tumor necrosis factor alpha (TNF-α) production. In rectal tissue, CD107 release was frequently coupled with production of IFN-γ or TNF-α. In patients not on antiretroviral therapy, the magnitude of Gag-specific responses, as a percentage of CD8+ T cells, was greater in the rectal mucosa than in PBMC (P = 0.054); however, the breakdown of responding cells into specific functional categories was similar in both sites. These findings demonstrate that rectal CD8+ T cells are capable of robust and varied HIV-1-specific responses and therefore likely play an active role in eliminating infected cells during chronic infection.


Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3958-3963 ◽  
Author(s):  
Shigeo Yamashiro ◽  
Ji-Ming Wang ◽  
De Yang ◽  
Wang-Hua Gong ◽  
Hidenobu Kamohara ◽  
...  

Polymorphonuclear leukocytes (PMNLs) are thought to be terminally differentiated, short-lived, and unable to actively synthesize new proteins or to interact with T cells. In the current study, it was found that PMNLs incubated with supernatants of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PHA-sup) expressed high levels of CCR6 mRNA. Neutralization with IgG against several cytokines revealed that tumor necrosis factor (TNF)-α was largely responsible for the PHA-sup–induced CCR6 mRNA expression. Among recombinant cytokines, TNF-α induced high levels of CCR6 mRNA expression, whereas interferon (IFN)-γ induced low levels. The 2 cytokines together exhibited a considerable synergy. Cytokine-activated PMNLs expressed functional CCR6, as detected by the binding of sodium iodide I 125–labeled liver and activation-regulated chemokine (LARC) and dose-dependent migration toward LARC. The induction of CCR6 suggested that these cytokine-activated PMNLs have more similarities with dendritic cells (DCs) that express CCR6 in an immature stage. In fact, the activation of PMNLs with TNF-α and IFN-γ induced the expression of CD83, a dominant cell-surface marker of DCs. When PMNLs were activated with granulocyte macrophage–colony-stimulating factor, TNF-α, and IFN-γ, these cells expressed CD40 and HLA-DR in addition to CD83. Taken together, PMNLs, under appropriate conditions, can undergo a differentiation process characterized by the acquisition of new phenotypes and functions, and such differentiated PMNLs may play more active roles in the adaptive immune response.


2017 ◽  
Vol 44 (4) ◽  
pp. 1526-1536 ◽  
Author(s):  
Wenlin Tai ◽  
Yiheng Xu ◽  
Jiawei Ding ◽  
Hanxin Wu ◽  
Ming Du ◽  
...  

Background/Aims: Acute lung injury (ALI) remains a severe disease that threatens human life around the world. To decrease the mortality of ALI and improve ALI treatment efficacy, the development of more ALI treatments is urgently needed. Whether fibrocytes directly participate in ALI has not been studied. Therefore, a mouse model of ALI was induced with lipopolysaccharide (LPS). Methods: Fibrocytes were harvested from peripheral blood mononuclear cells of bleomycin mice and identified by using flow cytometry to detect the expression of molecular makers. The fibrocytes were injected for the treatment of acute lung injury mice. The curative effects were evaluated by using ELISA to determine the cytokines (including TNF-α, IL-6 and IFN-γ) concentrations in bronchoalveolar lavage fluid (BALF) supernatant. Results: The concentrations of cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interferon-γ (IFN-γ) were increased in mice with ALI induced with LPS. The concentrations of TNF-α, IL-6, and IFN-γ as well as their mRNA and protein expression levels were decreased by administration of fibrocytes. The effect of fibrocytes in ameliorating ALI was time dependent. LPS treatment induced an increase in myeloperoxidase (MPO) activity, whereas the fibrocyte treatment caused inhibition of MPO activity as well as expression of the neutrophil-chemoattractant chemokine macrophage inflammatory protein 2 (MIP-2). Conclusion: Taken together, these data suggest that fibrocytes ameliorated ALI by suppressing inflammatory cytokines and chemokines as well as by decreasing the accumulation of neutrophils in the lung.


2013 ◽  
Vol 81 (10) ◽  
pp. 3750-3756 ◽  
Author(s):  
Arjan van Laarhoven ◽  
Jornt J. Mandemakers ◽  
Johanneke Kleinnijenhuis ◽  
Mimount Enaimi ◽  
Ekta Lachmandas ◽  
...  

ABSTRACTOne of the most widespread clades ofMycobacterium tuberculosisworldwide, the Beijing genotype family, consists of ancient (atypical) and modern (typical) strains. Modern Beijing strains outcompete ancient strains in terms of prevalence, while reserving a higher degree of genetic conservation. We hypothesize that their selective advantage lies in eliciting a different host immune response. Bead-disrupted lysates of a collection of differentM. tuberculosisstrains of the modern (n= 7) or ancient (n= 7) Beijing genotype, as well as the Euro-American lineage (n= 6), were used for induction ofex vivocytokine production in peripheral blood mononuclear cells (PBMCs) from 10 healthy individuals. Hierarchical clustering and multivariate regression analyses were used to study possible differences in production of nine cytokines. Modern and ancientM. tuberculosisBeijing genotypes induced different cytokine signatures. Overall induction of interleukin-1β (IL-1β), gamma interferon (IFN-γ), and IL-22 was 38 to 40% lower after stimulation with modern Beijing strains (correctedPvalues of <0.0001, 0.0288, and 0.0002, respectively). Euro-American reactivation strains induced 2-fold more TNF-α production than both types of Beijing strains. The observed differences in cytokine induction point to a reduction in proinflammatory cytokine response as a possible contributing factor to the evolutionary success of modern Beijing strains.


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