Soluble Immune Mediators Research Articles

Effect of IL-6 and related mediators on resistance to abiraterone acetate (abi) and enzalutamide (enza) in patients with metastatic castration-resistant prostate cancer (mCRPC).

296 Background: IL-6 is an upstream regulator of various moieties, including STAT3, that are associated with a poor prognosis in mCRPC. The specific association between these moieties and outcomes with enza and abi are as yet undefined. Methods: Pts receiving abi or enza in the course of routine clinical care were consented for blood collection at weeks 0, 4, 8, and 12 of therapy, and at the time of progression (based on PCWG3 criteria). PBMCs were isolated within 4 hours of blood collection and plasma samples were assessed for 30 soluble immune mediators using Luminex analysis. Flow cytometric analysis was used for characterization of CD3, CD4, CD8 and PD-1. CellSearch was used for CTC enumeration. Results: Of 36 patients consented, 21 received abi and 15 received enza. Median age in the cohort was 71 (range, 54-84). Median PSA was 21.9 ng/dL (range, 0-918.3) and mean CTC count was 158 (range, 0-2126). Median duration of therapy (DOT) with abi or enza was 10.5 mos (range, 1-53); pts were divided into two groups around median DOT. Median DOT in Group A and B were 4 mos (range, 1-10) and 49 mos (range, 11-53), respectively. Patients in Group A had higher levels of pre-treatment levels of IL-6, IL-10, GM-CSF, MIG and FGF, and higher expression of PD1 and FoxP3 on CD4+ T cells (P < 0.05 for each). In an exploratory analysis, patients with > 5 CTCs/7.5 mL of blood at baseline had higher levels of IL-6, although this was not statistically significant (P = 0.08). Conclusions: Elevated levels of IL-6 and several other cytokines are seen in patients with relative resistance to abi/enza for mCRPC. Surface expression of PD-1 and FoxP3 on CD4+ T-cells is also higher in the setting of resistance. The dual combination of elevated pro-inflammatory cytokines along with elevated immunosuppressive signals supports ongoing trials assessing checkpoint inhibition with abi/enza, as well as efforts by the current investigators to develop therapies antagonizing STAT3 (Moreira D et al CCR 2018).

Abstract P4-06-02: Chemoimmunotherapy with cyclophosphamide plus a toll-like receptor 9 (TLR9) agonist eradicates triple negative breast cancer in a murine model

Abstract Background. Toll-like receptors (TLR) recognize conserved molecular patterns expressed by microbes and together with other molecular sensors serve as a first line of defense, inducing soluble and cellular mediators of innate immunity and initiating key steps of an adaptive immune response. The use of TLR agonists for therapeutic purposes relies on the ability of these compounds to induce, at least partially, some of the immune events that occur during natural infections. For example, synthetic CpG-containing oligodeoxynucleotides (ODN) act as TLR9 agonists, mimicking stimulation of the immune system by bacterial or viral DNA. CpG ODNs are being developed for cancer immunotherapy based on their capacity to stimulate innate and adaptive anti-tumor responses. In this study, we examined the efficacy of intratumorally administered CpG-ODN 1826 alone or in combination with immunomodulatory antibodies (anti-PD-1, anti-OX40, anti-CTLA4) or chemotherapy (cyclophosphamide, paclitaxel) in the syngeneic mouse 4T1 breast tumor model. Methods. Tumors were implanted orthotopically in the mammary fat pads on the left and right flanks while only one tumor was injected with CpG-ODN 1826. Therapy began 12-14 days post tumor injection when tumors were 8-10 mm in diameter. CpG-ODN 1826 (100 ug) was administered intratumorally, while immunomodulatory antibodies (anti-PD-1 [200 ug], anti-CTLA4 [100 ug], anti-OX40 [400 ug]) and chemotherapies (cyclophosphamide [150 mg/kg], paclitaxel [10 mg/kg]) were administered intraperitoneally. Tumor volume was monitored on both flanks to assess direct and abscopal/systemic anti-tumor activity. Tumor tissue obtained during the treatment regimen was used to evaluate therapy-induced changes in the immune microenvironment. Results. CpG-ODN 1826, administered intratumorally over 5 consecutive days induced complete regressions in ˜50% of the treated tumors, but only delayed growth in the distant lesions. The immunomodulatory antibodies had little effect on their own and did not add to the therapeutic efficacy of CpG-ODN 1826. The best therapeutic efficacy was obtained with a combination of weekly cyclophosphamide + CpG-ODN 1826 resulting in complete regression of both the CpG injected tumors and the contralateral tumors in 100% of the mice. Conclusions. These data support the clinical investigation of the combination of a TLR9 agonist (CpG-ODN) with cyclophosphamide in women with breast cancer. Citation Format: Campbell MJ, Tandon V, Senman B, Li J, Esserman L. Chemoimmunotherapy with cyclophosphamide plus a toll-like receptor 9 (TLR9) agonist eradicates triple negative breast cancer in a murine model [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-02.

Role of soluble inflammatory mediators and different immune cell populations in early control of symptomatic acute hepatitis C virus infection.

The natural course of acute Hepatitis C Virus (aHCV) infection is highly heterogeneous, and only few biomarkers have been identified to reliably predict the outcome of infection. We analysed a large panel of soluble inflammatory mediators, immune cell frequencies and phenotypes using peripheral blood samples from 26 patients with symptomatic aHCV infection from a controlled randomized clinical trial (ISRCTN88729946, www.isrctn.com). We found that patients with a spontaneous early HCV control demonstrated a distinct expression pattern of various soluble immune mediators including IFNα and IL-16. Immune cell phenotype and frequency differed between patients who cleared the viral infection early (n=13) and those who remained HCV RNA positive after 12 weeks of observation (n=13) with a reduced ratio of CD4+ T cells to NK cells in the non-early clearer. Further, correlation analyses of 50 cytokines and chemokines revealed more positive correlations in between the distinct cytokines, especially for IFNα and IL-16, and between the cytokines and HCV RNA levels in spontaneous early clearer patients. Beyond that, in vitro stimulation of CD4+ T cells with IL-16 reduced the susceptibility of these cells to killing by IFNα-activated NK cells. These data indicate that the immune cell composition and cytokine pattern varies considerably in patients with symptomatic aHCV infection. NK cell-mediated killing of CD4+ T cells might affect early control of HCV infection.

Dysregulation in Genital Tract Soluble Immune Mediators in Postmenopausal Women Is Distinct by HIV Status.

A rise in new HIV diagnoses among older adults is characterized by poor prognosis and reduced survival times. Although heterosexual transmission remains the main route of infection in women, little is known regarding immune functions in the genital tract of postmenopausal women, especially those who are HIV positive. Furthermore, effects of hormone replacement therapy (HRT) on the genital tract immune system are unclear. Using the Women's Interagency HIV Study repository, we obtained cervical-vaginal lavage (CVL) samples from premenopausal and postmenopausal HIV-positive and HIV-negative women, some of whom were on HRT. Samples were assayed for interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, secretory leukocyte protease inhibitor (SLPI), Elafin, human beta defensin-2 (HBD2), and macrophage inflammatory protein (MIP)-3α using ELISA. Anti-HIV activity in CVL was measured using TZM-bl indicator cells. Among HIV-positive women, the plasma viral load was significantly higher and CD4 count was significantly lower in postmenopausal compared with premenopausal women. Postmenopausal women, irrespective of HIV status, had significantly lower levels of HBD2 compared with premenopausal women. Among the HIV-negative individuals, postmenopausal women had significantly lower levels of MIP-3α, IL-6, and SLPI compared with premenopausal women. In contrast, HIV-positive postmenopausal women had significantly higher levels of TNF-α compared with HIV-positive premenopausal women. In most cases, HRT groups resembled the postmenopausal groups. No significant differences in anti-HIV activity by menopausal or by HIV status were noted. Our findings indicate that the female genital tract immune microenvironment is distinct by menopausal status and HIV status. Further studies are needed to assess the risk of HIV acquisition/transmission in this population.

Association between soluble immune mediators and tumor responses in patients with nonsmall cell lung cancer treated with anti-PD-1 inhibitor.

Although programmed death (PD)-1 immune checkpoint therapies target the immune system, the relationship between inflammatory factors and the clinical outcome of anti-PD-1 therapy for nonsmall cell lung cancer (NSCLC) is not fully understood. Here we examined the association between soluble immune mediators and the outcome of treatment with PD-1 inhibitors in patients with advanced/recurrent NSCLC. In two independent cohorts, we assessed the levels of 88 different soluble immune mediators in peripheral blood before and after anti-PD-1 treatment, and evaluated their associations with clinical outcomes. In the training cohort, the plasma levels of chitinase 3-like-1 and GM-CSF before treatment (p = 0.006 and p = 0.005, respectively) and changes in the plasma levels of CXCL2, VEGF, IFNα2, and MMP2 after treatment (p < 0.001, p = 0.019, p = 0.019, and p = 0.012, respectively) were significantly correlated with PFS. The change in the plasma CXCL2 level was also significantly associated with treatment-related AEs (p = 0.017). In the validation cohort, however, only the changes in the plasma levels of CXCL2 and MMP2 after treatment were associated with PFS (p = 0.003 and p = 0.006, respectively), and these changes were maintained during the course of anti-PD-1 therapy in patients who showed better clinical outcomes, even in those with tumor pseudoprogression. Since CXCL2 and MMP2 can be easily measured by minimally invasive blood sampling, they could be useful for monitoring of clinical outcomes in NSCLC patients receiving PD-1 inhibitor therapy.

Viral dominance patterns in chronic hepatitis delta determine early response to interferon alpha therapy

Chronic hepatitis D is caused by coinfection of hepatitis B and hepatitis D virus. While HDV is the dominant virus over HBV in the majority of cases, mechanisms and consequences of viral dominance are largely unknown. We aimed to investigate associations between viral dominance patterns and patients' characteristics and inflammatory features; 109 HDV-infected patients treated with PEG-IFNa-2α within the international multicentre, prospective HIDIT-2 trial were studied. Patients were classified as D- or B-dominant if the viral load of one virus exceeded that of the other virus by more than 1log10 . Otherwise, no viral dominance (ND) was described. We used Luminex-based multiplex technology to study 50 soluble immune mediators (SIM) in pretreatment samples of 105 HDV RNA-positive patients. Dominance of HDV was evident in the majority (75%) of cases. While only 7% displayed B-dominance, 17% showed nondominance. D-dominance was associated with downregulation of 4 interleukins (IL-2ra, IL-13, IL-16 and IL-18) and 5 chemokines/cytokines (CTACK (CCL27), MCP-1 (CCL2), M-CSF, TRAIL and ICAM-1) while no analyte was increased. In addition, D-dominance could be linked to a delayed HDV RNA response to pegylated interferon as patients with B-dominance or nondominance showed higher early HDV RNA responses (61% at week 12) than D-dominant patients (11%; P<.001). In conclusion, this study revealed unexpected effects of viral dominance on clinical and immunological features in chronic hepatitis delta patients. Individualizing PEG-IFNa-2α treatment duration should consider viral dominance. Overall, our findings suggest an activated but exhausted IFN system in D-dominant patients.

Ischemia Reperfusion Injury Significantly Differs between Lung vs. Heart Transplantation with Respect to Lead Cytokines and Correlation to Clinical Outcome

Objectives Ischemia reperfusion injury (IRI) is known to impair early graft function after lung (LTx) or heart (HTx) transplantation. We have previously characterized IRI in recipients of lungs preserved by standard cold storage by a peak response directly after Tx. The lead cytokines involved in IRI after LTx were, amongst others, IL-6, CXCL8, CCL2. Since organ-specific aspects of IRI are not well understood, we aimed to define IRI in HTx and to identify differences with respect to this peak cytokine/chemokine response. Methods Plasma samples of LTx or HTx recipients were analysed preTx, at T0, T24, as well as respective perfusion solutions. 26 LTx recipients (mean age 49y) and 13 HTX recipients (mean age 47y) were included into the study. Protein concentrations of 99 cytokines, chemokines, angiogenic factors were determined using multiplex assays. Clinical data, i.e. cold ischemic time (CIT), immunosuppression etc. were also collected. Principal component (PCA), unsupervised cluster and K-network classifier (KNN) analyses were performed for the identification of the lead factors of IRI in LTx vs. HTx. Results KNN, unsupervised cluster and PCA analyses identified IL-6 as strongest signal for IRI in LTx recipients (preTx/T0 p<0.001) and high IL-6 levels correlated with PGD>2, CIT and PaO2/FiO2 ratio. In contrast, IL-10 was leading in HTx (preTx/T0 p<0.001), being sufficient to discriminate between preTx and T0 plasma samples on its own. Advanced statistics of LTx samples identified IL-10, IGFBP1, CXCL8, G-SCF, HGF and IL-16 (all p<0.01) as top discriminators. The overlap to HTx samples comprises IGFBP1, IL-16 (all p<0.001), but of note, not IL-6. Instead, SCGF, M-CSF, VCAM, sVEGFR1, and the Tie2/Ang-2 and PAI-1/uPA ratios (all p<0.001) dominated the IRI response in HTx patients. These differences were also observed in perfusion solutions of hearts vs. lungs after standard cold preservation (all p<0.001). Conclusion The comparison of soluble immune mediators in plasma of lung vs. heart recipients revealed significant differences in IRI response, especially regarding the lead cytokines IL-6 and IL-10. These differences are likely to reflect organ-specific components in IRI. Thus, different biomarker candidates may be useful for the quantification of IRI in lung vs. heart transplant patients. IFB-Tx OPEX_2. SFB738, B3.

Vagal dysfunction and small intestinal bacterial overgrowth: novel pathways to chronic inflammation in HIV.

Chronic inflammation in HIV-infected individuals drives disease progression and the development of comorbidities, despite viral suppression with combined antiretroviral therapy. Here, we sought evidence that vagal dysfunction, which occurs commonly as part of HIV-associated autonomic neuropathy, could exacerbate inflammation through gastrointestinal dysmotility, small intestinal bacterial overgrowth (SIBO), and alterations in patterns of soluble immune mediators. This is a cross-sectional observational study. Forty participants on stable combined antiretroviral therapy with gastrointestinal symptoms, and no causes for vagal or gastrointestinal dysfunction other than HIV, underwent autonomic testing, hydrogen/methane breath testing for SIBO, and gastric emptying scintigraphy. A panel of 41 cytokines, high-mobility group box 1, and markers of bacterial translocation (lipopolysaccharide) and monocyte/macrophage activation (sCD14 and sCD163) were tested in plasma. We found that participants with vagal dysfunction had delayed gastric emptying and higher prevalence of SIBO. SIBO was associated with IL-6, but not sCD14; lipopolysaccharide could not be detected in any participant. We also found alteration of cytokine networks in participants with vagal dysfunction, with stronger and more numerous positive correlations between cytokines. In the vagal dysfunction group, high mobility group box 1 was the only soluble mediator displaying strong negative correlations with other cytokines, especially those cytokines that had numerous other strong positive correlations. The current study provides evidence that the vagal component of HIV-associated autonomic neuropathy is associated with changes in immune and gastrointestinal function in individuals with well treated HIV. Further study will be needed to understand whether therapies targeted at enhancing vagal function could be of benefit in HIV.

DsRNA induced intestinal epithelial cell activation of immune dysfunction in type 1 diabetes

Abstract Environmental factors contribute to the initiation, progression, and maintenance of many autoimmune diseases including type 1 diabetes (T1D). We propose the context in which an environmental signal is received by the intestinal epithelial cell (IEC) may be more important to disease than the specific identity of the environmental factor. Viral infections are proposed to be one such trigger. IEC-specific responses to double-stranded RNA, a common intermediate in many viral life cycles, was evaluated by comparing and contrasting the expression of soluble immune mediators from T1D and non-T1D derived primary (murine and human) IECs. The effect of the soluble mediator milieu on innate and adaptive immune cell phenotype and function was also assessed. While poly I:C induces a robust induction of IFN-I in primary IEC derived from non-T1D sources, a significantly less robust IFN-I response was observed in T1D-derived IECs. Similarly, a significantly less robust induction of IL-18, TSLP, and IL-17C mRNA was observed in T1D-derived IECs cultures whereby this hyporesponsive phenotype became more apparent in T1D-IEC derived at later stages of disease. Supernatants from T1D-derived IECs induced an M1 macrophage phenotype and directly enhanced CD3/CD28 induced T cell proliferation. T cells induced to proliferate were polarized to a more Th(c)1 or Th(c)1/Th(c)7 phenotype at the expense of a Th(c)17 phenotype. Supernatants from T1D-derived IECs also enhanced β-cell killing by transgenic T cells. These data support our hypothesis that IECs are key players in driving innate and adaptive immune dysfunction observed in the gastrointestinal track of individuals with T1D, as well as capable of supporting and expanding an autoreactive T cell repertoire.

Host Soluble Mediators: Defying the Immunological Inertness of Aspergillus fumigatus Conidia.

Aspergillus fumigatus produce airborne spores (conidia), which are inhaled in abundant quantity. In an immunocompromised population, the host immune system fails to clear the inhaled conidia, which then germinate and invade, leading to pulmonary aspergillosis. In an immunocompetent population, the inhaled conidia are efficiently cleared by the host immune system. Soluble mediators of the innate immunity, that involve the complement system, acute-phase proteins, antimicrobial peptides and cytokines, are often considered to play a complementary role in the defense of the fungal pathogen. In fact, the soluble mediators are essential in achieving an efficient clearance of the dormant conidia, which is the morphotype of the fungus upon inhalation by the host. Importantly, harnessing the host soluble mediators challenges the immunological inertness of the dormant conidia due to the presence of the rodlet and melanin layers. In the review, we summarized the major soluble mediators in the lung that are involved in the recognition of the dormant conidia. This knowledge is essential in the complete understanding of the immune defense against A. fumigatus.

Peripheral Immune Profile and Minimal Residual Disease (MRD) Burden Following Autologous Stem Cell Transplantation (ASCT) in Multiple Myeloma (MM)

BACKGROUND: The immune system plays an essential role in both promoting and inhibiting the growth of MM. Loss of anti-myeloma immunity involves altered activation and polarization of effector cells as well as immunosuppressive cytokines. Immune dysfunction associated with MM can be partially or totally reversed when patients achieve clinical remission. Detection of MRD has become an achievable goal in MM, and is a powerful predictor of progression-free survival and overall survival. We hypothesized that the immune profile of MRDpos patients is distinct from MRDneg patients.PATIENTS AND METHODS: We studied peripheral NK, NK-T and T cell distribution/activation, and measured bone marrow MRD status by flow cytometry in 30 newly diagnosed MM patients 60+ days after ASCT. Patients were divided in 2 groups based on κ/λ ratio and MM-plasma cell (MM-PC) distribution: MRDneg (n=6), with κ/λ ratio ≤1.8 and MM-PC≤15 per million or MRDpos (n=24), with MM-PC>15 per million. Plasma was also collected from 17 of these patients (5 MRDneg and 12 MRDpos) 60+ days after ASCT to quantify inflammatory cytokines, chemokines and growth factors by multiplex protein assay. Linear regression was used to determine association between each tested variable (25 by flow cytometry and 27 by multiplex protein assay) and MRD status. Unsupervised hierarchical cluster analysis was then applied to post-ASCT samples with selected variables that were differentially expressed between MRDneg and MRDpos patients (p<0.1) using complete linkage and Euclidean distances.RESULTS: More than a third of immune variables tested by flow cytometry (9/25) were significantly differential between MRDpos and MRDneg patients (p<0.1). Most significantly, MRDpos patients had fewer circulating CD56high NK cells than MRDneg (p=0.02). While NK cells had a propensity to be highly activated (90% NKG2D+) among MRDpos patients, they displayed an impaired killing phenotype with decreased KIR3DL1 expression compared with their MRDneg counterpart (p=0.01). NK-T and T cell distributions were not influenced by MRD status after ASCT, but phenotypically NK-T cells in MRDpos patients exhibited higher expression of NKG2D (p=0.05), but lacked NKG2A and Tim3 expression, indicative of greater mobilization. Plasma concentrations of all 27 soluble immune analytes tested were higher in MRDneg compared with MRDpos patients. Specifically, 2 pro-inflammatory cytokines [IL-12p70, IL-17] and 3 pro-angiogenic growth factors [FGF, PDGF, and VEGF] were highly correlated with MRD status (p<0.1). Unsupervised hierarchical clustering using all differentially expressed cellular and soluble immune markers showed better separation of MRDneg and MRDpos subgroups than using cellular or soluble immune markers separately (heat-map below).CONCLUSION: A comprehensive analysis of 52 immune variables assessing cytotoxic cell distribution, mobilization, killing potential, inflammatory status, immune polarization chemotaxis and angiogenesis revealed distinct differences in peripheral immunity between MRDpos and MRDneg MM patients after ASCT. Fewer circulating NK cells exhibiting a loss of killing potential characterized immune dysfunction among MRDpos patients. On the other hand, MRDneg patients more frequently displayed an inflammatory and pro-angiogenic cytokine profile. Taken together, these observations suggest that MRD represents a state of immune equilibrium where detectable or undetectable myeloma cells remain under surveillance by cellular and soluble immune mediators. As a next step, we are validating our observation in a larger prospective cohort by assessing peripheral immune profile as a predictor for MRD negativity. [Display omitted] DisclosuresSymanowski:Eli Lilly & Co: Consultancy; Ra Pharma: Consultancy; Caris Life Sciences: Consultancy; Endocyte: Consultancy. Avalos:Seattle Genetics: Membership on an entity’s Board of Directors or advisory committees. Usmani:BioPharma: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics: Research Funding; Onyx: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Britsol-Myers Squibb: Consultancy, Research Funding; Millenium: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Array: Research Funding; Janssen: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Skyline: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Takeda: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Research Funding, Speakers Bureau. Bhutani:Takeda Oncology: Research Funding, Speakers Bureau; Prothena: Research Funding; Bristol-Myers Squibb: Speakers Bureau; Onyx, an Amgen subsidiary: Speakers Bureau.

The Systemic Profile of Soluble Immune Mediators in Patients with Myelodysplastic Syndromes.

Introduction: Myelodysplastic syndromes (MDS) are characterized by bone marrow failure due to disturbed bone marrow maturation. MDS is associated with increased risk of transformation to acute myeloid leukemia (AML) and features of immunological dysregulation. Materials and methods: Serum levels of 47 soluble immune mediators were examined in samples derived from 49 MDS patients (35 low-risk and 14 high-risk) and 23 healthy adults. Our patients represent an unselected population-based cohort. The mediators included cytokines, soluble adhesion proteins, matrix metalloproteases, and tissue inhibitors of proteases. Levels were determined using Luminex assays. Patients were classified as low- and high-risk based on the international prognostic scoring system (IPSS) score. Results: When comparing the serum levels of single mediators the MDS patients showed a relatively wide variation range for several mediators compared with healthy adults, especially interleukin 6 (IL-6), IL-8/CXCL8, CCL3, and CCL4. The high-risk patients had lower levels of epidermal growth factor (EGF), cluster of differentiation 40 ligand (CD40L), CCL5, CCL11, CXCL5, matrix metalloproteinase 1 (MMP-1), MMP-9, and tissue inhibitor of metalloproteinases 2 (TIMP-2) compared with low-risk patients. Unsupervised hierarchical cluster analysis visualized marked serum mediator profile differences between MDS patients; based on this analysis three patient subsets could be identified. The healthy adults were also included in this analysis and, as expected, they formed their own separate cluster, except for one outlier. Both low- and high-risk patients showed considerable heterogeneity with regard to serum profile, and this heterogeneity seems stable over time (one year follow-up). Finally, very few mediators differed between low- and high-risk patients, but hierarchical clustering based both on all mediators, as well as five selected mediators (EGF, CCL11, TIMP-2, MMP-1, and MMP-9) identified subsets of patients with significantly increased frequency of high-risk disease (χ-square test p = 0.0158 and p = 0.0148).

Immune Response of Amebiasis and Immune Evasion by Entamoeba histolytica.

Entamoeba histolytica is a protozoan parasite and the causative agent of amebiasis. It is estimated approximately 1% of humans are infected with E. histolytica, resulting in an estimate of 100,000 deaths annually. Clinical manifestations of amebic infection range widely from asymptomatic to severe symptoms, including dysentery and extra-intestinal abscesses. Like other infectious diseases, it is assumed that only ~20% of infected individuals develop symptoms, and genetic factors of both the parasite and humans as well as the environmental factors, e.g., microbiota, determine outcome of infection. There are multiple essential steps in amebic infection: degradation of and invasion into the mucosal layer, adherence to the intestinal epithelium, invasion into the tissues, and dissemination to other organs. While the mechanisms of invasion and destruction of the host tissues by the amebae during infection have been elucidated at the molecular levels, it remains largely uncharacterized how the parasite survive in the host by evading and attacking host immune system. Recently, the strategies for immune evasion by the parasite have been unraveled, including immunomodulation to suppress IFN-γ production, elimination of immune cells and soluble immune mediators, and metabolic alterations against reactive oxygen and nitrogen species to fend off the attack from immune system. In this review, we summarized the latest knowledge on immune reaction and immune evasion during amebiasis.

The effect of sex on immune cells in healthy aging: elderly women have more robust natural killer (NK) lymphocytes than do elderly men

Abstract Gender differences in blood leukocytes and immune responses have been reported, but there is limited knowledge of gender differences in elderly humans. We compared monocyte and lymphocyte subsets, along with soluble immune mediators in healthy men and women over the age of 70. We also measured natural killer (NK) lymphocyte cytotoxic granule exocytosis, chemokine synthesis, and cytokine synthesis in response to a variety of stimuli. We found that elderly women had significantly more circulating B cells than men, whereas men had more CD4 central memory T cells. Men also had higher monocyte levels. Women had a higher ratio of immature CD56bright NK cells to mature CD56dim NK cells, indicating a gender difference in NK cell maturation in the elderly. Moreover, compared with NK cells from men, mature NK cells from women had more vigorous cytotoxic granule responses to K562 leukemia cells and IFN-g responses to NKp46 crosslinking. Female mature NK cells were also more likely to produce MIP-1b than male mature NK cells in response to a variety of stimuli. We also measured soluble factors that affect immune cells or are produced by immune cells. Plasma adiponectin levels were higher in women, plasma levels of retinol-binding protein 4 were higher in men, but there was no significant gender difference in C-reactive protein, IL-15, or sphingosine-1-phosphate. These data support the hypothesis that gender influences immunity in general, and NK cell activity in particular, in elderly humans.

The effect of sex on immune cells in healthy aging: Elderly women have more robust natural killer lymphocytes than do elderly men

Immune gender differences have been reported, but are little studied in elderly humans. We compared monocyte and lymphocyte subsets, along with soluble immune mediators in healthy men and women over the age of 70. We also measured natural killer (NK) lymphocyte cytotoxic granule exocytosis, chemokine synthesis, and cytokine synthesis in response to a variety of stimuli. Elderly women had significantly more circulating B cells than men, whereas men had more CD4 central memory T cells and higher monocyte levels. Plasma adiponectin levels were higher in women, plasma retinol-binding protein 4 levels were higher in men, but there were no significant gender differences in C-reactive protein, IL-15, or sphingosine-1-phosphate. Women had a higher ratio of immature CD56bright NK cells to mature CD56dim NK cells, indicating a gender difference in NK cell maturation in the elderly. Comparing sexes, female mature NK cells had more vigorous cytotoxic granule responses to K562 leukemia cells and IFN-γ responses to NKp46 crosslinking. Moreover, female NK cells were more likely to produce MIP-1β in response to a variety of stimuli. These data show that gender influences NK cell activity in elderly humans.

Candidate Soluble Immune Mediators in Young Women with High-Risk Human Papillomavirus Infection: High Expression of Chemokines Promoting Angiogenesis and Cell Proliferation.

BackgroundThe causal interpretation of cervical immune response to Human Papillomavirus (HPV) infection is complex and poorly characterized mainly due to the delicate balance that exists between viral infection, increase of inflammatory cytokines and host risk factors. This study aims to explore the significance of cervical immune mediators associated to cell survival, angiogenesis and interaction with immune response, in predicting the risk to develop HPV-related intraepithelial lesions.MethodsA panel of 48 cytokines and growth factors were explored in a selected cohort of 168 immunocompetent women including 88 diagnosed with low (LSIL) or high (HSIL) squamous intraepithelial lesions of the cervix and 80 with normal cervical cytology (NIL). HPV genotyping was performed by Linear Array HPV test and the soluble concentration of 48 immune molecules was analyzed using the Bio-Plex platform.ResultsThe prevalence of single HR-HPV infection was 30% in NIL and 100% in LSIL and HSIL women. The expression of 13 cytokines, including interleukins IL-6, IL-3, IL-12p40, IL-12p70, IL-16, IL-18, LIF, of chemokines CCL7 (MCP-3), CXCL9 (MIG), CXCL12 (SDF-1α) and of the tropic factors VEGF, G-CSF, M-CSF were significantly associated with the presence of infection, with levels being higher in women with precancerous lesions compared to NIL HPV negative women. Only the growth factor GM-CSF was positively associated with the cytological abnormalities.ConclusionsThe ability of HR-HPV to escape from innate immune recognition and to orchestrate the production of specific inflammatory and growth factors, involved in early inflammatory response and in the cell-proliferating phase of intraepithelial damage, was documented in women before the development of cervical lesions.

Human mesenchymal stromal cells reduce influenza A H5N1-associated acute lung injury in vitro and in vivo

Influenza can cause acute lung injury. Because immune responses often play a role, antivirals may not ensure a successful outcome. To identify pathogenic mechanisms and potential adjunctive therapeutic options, we compared the extent to which avian influenza A/H5N1 virus and seasonal influenza A/H1N1 virus impair alveolar fluid clearance and protein permeability in an in vitro model of acute lung injury, defined the role of virus-induced soluble mediators in these injury effects, and demonstrated that the effects are prevented or reduced by bone marrow-derived multipotent mesenchymal stromal cells. We verified the in vivo relevance of these findings in mice experimentally infected with influenza A/H5N1. We found that, in vitro, the alveolar epithelium's protein permeability and fluid clearance were dysregulated by soluble immune mediators released upon infection with avian (A/Hong Kong/483/97, H5N1) but not seasonal (A/Hong Kong/54/98, H1N1) influenza virus. The reduced alveolar fluid transport associated with down-regulation of sodium and chloride transporters was prevented or reduced by coculture with mesenchymal stromal cells. In vivo, treatment of aged H5N1-infected mice with mesenchymal stromal cells increased their likelihood of survival. We conclude that mesenchymal stromal cells significantly reduce the impairment of alveolar fluid clearance induced by A/H5N1 infection in vitro and prevent or reduce A/H5N1-associated acute lung injury in vivo. This potential adjunctive therapy for severe influenza-induced lung disease warrants rapid clinical investigation.

Immune suppression of JC virus gene expression is mediated by SRSF1.

Progressive multifocal leukoemcephalopathy (PML) is a fatal demyelinating disease caused by the human neurotropic JC virus (JCV). JCV infects the majority of the human population during childhood and establishes a latent/persistent life-long infection. The virus reactivates under immunosuppressive conditions by unknown mechanisms, resulting in productive infection of oligodendrocytes in the central nervous system (CNS). Given the fact that the natural occurrence of PML is strongly associated with immunosuppression, the functional and molecular interaction between glial cells and neuroimmune signaling mediated by soluble immune mediators is likely to play a major role in reactivation of JCV and the progression of the lytic viral life cycle leading to the development of PML. In order to explore the effect of soluble immune mediators secreted by peripheral blood mononuclear cells (PBMCs) on JCV transcription, primary human fetal glial (PHFG) cells were treated with conditioned media from PBMCs. We observed a strong suppression of JCV early as well as late gene transcription in cells treated with conditioned media from induced PBMCs. Using a variety of virological and molecular biological approaches, we demonstrate that immune mediators secreted by PBMCs induce the expression of SRSF1, a strong inhibitor of JCV gene expression, and inhibit the replication of JCV. Our results show that downregulation of SRSF1 in glial cells overcomes the suppression of JCV gene expression and its replication mediated by soluble immune mediators. These findings suggest the presence of a novel immune signaling pathway between glial cells and PBMCs that may control JCV gene expression during the course of viral reactivation.

Does peripheral blood NK cell associate with hyperglycemic disorders in pregnant women?

Immune gender differences have been reported, but are little studied in elderly humans. We compared monocyte and lymphocyte subsets, along with soluble immune mediators in healthy men and women over the age of 70. We also measured natural killer (NK) lymphocyte cytotoxic granule exocytosis, chemokine synthesis, and cytokine synthesis in response to a variety of stimuli. Elderly women had significantly more circulating B cells than men, whereas men had more CD4 central memory T cells and higher monocyte levels. Plasma adiponectin levels were higher in women, plasma retinol-binding protein 4 levels were higher in men, but there were no significant gender differences in C-reactive protein, IL-15, or sphingosine-1-phosphate. Women had a higher ratio of immature CD56bright NK cells to mature CD56dim NK cells, indicating a gender difference in NK cell maturation in the elderly. Comparing sexes, female mature NK cells had more vigorous cytotoxic granule responses to K562 leukemia cells and IFN-γ responses to NKp46 crosslinking. Moreover, female NK cells were more likely to produce MIP-1β in response to a variety of stimuli. These data show that gender influences NK cell activity in elderly humans.

P06.05 Dynamics of vaginal immune correlates and microbiota in women from sub-saharan africa

Introduction Alterations in vaginal microbiota (VMB) have been shown to increase HIV acquisition and transmission in women. We carried out a longitudinal characterisation of the VMB, soluble cervicovaginal immune mediators and their determinants in women from Sub-Saharan Africa. Methods Cervicovaginal lavages from two cohorts of sexually active women from Kenya, South Africa and Rwanda were analysed for IL-1α, IL-1β, IL-6, IL-12(p70), MIP-1β, IP-10, IL-8, GM-CSF, G-CSF, Elafin, SLPI, IL-1RA and total protein. qPCR was used to quantify total Lactobacillus , L. crispatus, L. iners , L. jensenii , L. gasseri, L. vaginalis, A. vaginae, G. vaginalis , P. bivia and E. coli in vaginal swab samples. Cohort A had 40 women with a healthy VMB (Nugent score 7) in the course of their visits. Results Cohort A: Individual Lactobacillus species were consistently present or absent within each woman over five study visits. Sexual activity was associated with reduced counts of total Lactobacillus , L. iners and Prevotella bivia but increased concentrations of IL-6, IL-12(p70) and IP-10. pH was positively associated with IL-1RA and IL1RA/IL1(α+β) ratio but negatively associated with total protein and SLPI. The amount of total Lactobacillus was significantly lower and total soluble immune mediators, MIP-1β and IL-8 higher in 14 women on progesterone-only contraception compared to those with a cycle (20 not on any contraceptives and 6 on combined pill). Cohort B: Total Lactobacillus , L. crispatus , IP-10, GM-CSF, Elafin, SLPI and total protein were all reduced during the first visit with BV. Conversely, G. vaginalis , A. vaginae, E. coli and IL-1β were increased with incident BV. Conclusion Sexual activity, progesterone, clinical symptoms of pathology and BV alter vaginal mucosal immunity in Sub-Saharan African women potentially increasing their susceptibility to HIV infection. Disclosure of interest statement This work was supported by the European and Developing Countries Clinical Trials Partnership (EDCTP) as part of a grant titled ‘‘Characterisation of novel microbicide safety biomarkers in East and South Africa.’’ The views expressed in this manuscript are those of the authors and do not necessarily represent the views of EDCTP. The authors report no conflict of interest.