Browsing by Subject "Leukocytes, Mononuclear"

Now showing 1 - 5 of 5
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    The altered mononuclear cell-derived cytokine response to glucose ingestion is not regulated by excess adiposity in polycystic ovary syndrome
    (The Endocrine Society, 2014-11) González, Frank; Sia, Chang Ling; Shepard, Marguerite K.; Rote, Neal S.; Minium, Judi; Department of Obstetrics & Gynecology, IU School of Medicine
    CONTEXT: Excess adipose tissue is a source of inflammation. Polycystic ovary syndrome (PCOS) is a proinflammatory state and is often associated with excess abdominal adiposity (AA) alone and/or frank obesity. OBJECTIVE: To determine the effect of glucose ingestion on cytokine release from mononuclear cells (MNC) in women with PCOS with and without excess AA and/or obesity. DESIGN: A cross-sectional study. SETTING: Academic medical center. PATIENTS: Twenty-three women with PCOS (seven normal weight with normal AA, eight normal weight with excess AA, eight obese) and 24 ovulatory controls (eight normal weight with normal AA, eight normal weight with excess AA, eight obese). INTERVENTION: Three-hour 75-g oral glucose tolerance test (OGTT). MAIN OUTCOME MEASURES: Body composition was measured by dual energy x-ray absorptiometry. Insulin sensitivity was derived from the OGTT (ISOGTT). TNFα, IL-6, and IL-1β release was measured in supernatants of cultured MNC isolated from blood samples drawn while fasting and 2 hours after glucose ingestion. RESULTS: Insulin sensitivity was lower in obese subjects regardless of PCOS status and in normal-weight women with PCOS compared with normal-weight controls regardless of body composition status. In response to glucose ingestion, MNC-derived TNFα, IL-6, and IL-1β release decreased in both normal-weight control groups but failed to suppress in either normal-weight PCOS group and in obese women regardless of PCOS status. For the combined groups, the cytokine responses were negatively correlated with insulin sensitivity and positively correlated with abdominal fat and androgens. CONCLUSIONS: Women with PCOS fail to suppress MNC-derived cytokine release in response to glucose ingestion, and this response is independent of excess adiposity. Nevertheless, a similar response is also a feature of obesity per se. Circulating MNC and excess adipose tissue are separate and distinct sources of inflammation in this population.
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    Evidence of mononuclear cell preactivation in the fasting state in polycystic ovary syndrome
    (Elsevier, 2014-12) González, Frank; Kirwan, John P.; Rote, Neal S.; Minium, Judi; Department of Obstetrics and Gynecology, IU School of Medicine
    OBJECTIVE: We evaluated mononuclear cell (MNC) preactivation in women with polycystic ovary syndrome (PCOS) by examining the effect of in vitro lipopolysaccharide (LPS) exposure on cytokine release in the fasting state. STUDY DESIGN: Twenty women with PCOS (10 lean, 10 obese) and 20 weight-matched controls (10 lean, 10 obese) volunteered for study participation. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) release was measured from mononuclear cells isolated from fasting blood samples and cultured in the presence and absence of LPS. Plasma IL-6 was measured from the same fasting blood samples. Insulin sensitivity was derived from an oral glucose tolerance test using the Matsuda index, and truncal fat was measured by dual-energy x-ray absorptiometry. RESULTS: The percent change from baseline in TNF-α and IL-6 release from MNC following LPS exposure was increased (P < .04) in lean and obese women with PCOS and obese controls compared with lean controls. Plasma IL-6 was increased (P < .02) in obese women with PCOS compared with lean women with PCOS, which in turn was increased (P < .02) compared with lean controls. The MNC-derived TNF-α and IL-6 responses from MNCs were negatively correlated with insulin sensitivity (P < .03) and positively correlated with testosterone (P < .03) and androstenedione (P < .006) for the combined groups. Plasma IL-6 was positively correlated with percentage truncal fat (P < .008). CONCLUSION: In PCOS, increased cytokine release from MNCs following LPS exposure in the fasting state reveals the presence of MNC preactivation. Importantly, this phenomenon is independent of obesity and may contribute to the development of insulin resistance and hyperandrogenism in PCOS. In contrast, the source of plasma IL-6 elevations in PCOS may be excess adiposity.
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    Hepatitis B e antigen induces the expansion of monocytic myeloid-derived suppressor cells to dampen T-cell function in chronic hepatitis B virus infection
    (PLOS, 2019-04-18) Yang, Feifei; Yu, Xueping; Zhou, Chenliang; Mao, Richeng; Zhu, Mengqi; Zhu, Haoxiang; Ma, Zhenxuan; Mitra, Bidisha; Zhao, Gan; Huang, Yuxian; Guo, Haitao; Wang, Bin; Zhang, Jiming; Microbiology and Immunology, School of Medicine
    Chronic hepatitis B virus (HBV) infection is associated with functionally impaired virus-specific T cell responses. Although the myeloid-derived suppressor cells (MDSCs) are known to play a critical role in impairing antiviral T cell responses, viral factors responsible for the expansion of MDSCs in chronic hepatitis B (CHB) remain obscure. In order to elucidate the mechanism of monocytic MDSCs (mMDSCs) expansion and T cell function suppression during persistent HBV infection, we analyzed the circulation frequency of mMDSCs in 164 CHB patients and 70 healthy donors, and found that the proportion of mMDSCs in HBeAg (+) CHB patients was significantly increased compared to that in HBeAg (-) patients, which positively correlated with the level of HBeAg. Furthermore, exposure of peripheral blood mononuclear cells (PBMCs) isolated from healthy donors to HBeAg led to mMDSCs expansion and significant upregulation of IL-1β, IL-6 and indoleamine-2, 3-dioxygenase (IDO), and depletion of the cytokines abrogated HBeAg-induced mMDSCs expansion. Moreover, HBeAg-induced mMDSCs suppressed the autologous T-cell proliferation in vitro, and the purified mMDSCs from HBeAg (+) subjects markedly reduced the proliferation of CD4+ and CD8+ T cells and IFN-γ production, which could be efficiently restored by inhibiting IDO. In summary, HBeAg-induced mMDSCs expansion impairs T cell function through IDO pathway and favors the establishment of a persistent HBV infection, suggesting a mechanism behind the development of HBeAg-induced immune tolerance.
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    Hyperandrogenism induces a proinflammatory TNFα response to glucose ingestion in a receptor-dependent fashion
    (The Endocrine Society, 2014-05) González, Frank; Sia, Chang Ling; Bearson, Dawn M.; Blair, Hilary E.; Department of Obstetrics and Gynecology, IU School of Medicine
    CONTEXT: Hyperandrogenism and inflammation are related in polycystic ovary syndrome (PCOS). Hyperandrogenemia can induce inflammation in reproductive-age women, but the mechanism for this phenomenon is unclear. OBJECTIVE: We examined the in vivo and in vitro effects of hyperandrogenism on mononuclear cell (MNC)-derived androgen receptor (AR) status and TNFα release. DESIGN: This study combined a randomized, controlled, double-blind protocol with laboratory-based cell culture experiments. SETTING: This work was performed in an academic medical center. PARTICIPANTS: Lean, healthy, reproductive-age women were treated with 130 mg of dehydroepiandrosterone (DHEA) or placebo (n = 8 subjects each) for 5 days and also provided untreated fasting blood samples (n = 12 subjects) for cell culture experiments. MAIN OUTCOME MEASURES: AR mRNA content and TNFα release were measured before and after DHEA administration in the fasting state and 2 hours after glucose ingestion. TNFα release in the fasting state was also measured in cultured MNCs exposed to androgens with or without flutamide preincubation. RESULTS: At baseline, subjects receiving DHEA or placebo exhibited no significant difference in androgens and TNFα release from MNCs before and after glucose ingestion. Compared with placebo, DHEA administration raised levels of T, androstenedione, and DHEA sulfate, and increased MNC-derived AR mRNA content and TNFα release in the fasting state and in response to glucose ingestion. Compared with MNC exposure to baseline concentrations of DHEA (175 ng/dL) or T (50 ng/dL), the absolute change in TNFα release increased after exposure to T concentrations of 125 and 250 ng/dL and a DHEA concentration of 1750 ng/dL. Preincubation with flutamide reduced the TNFα response by ≥ 60% across all T concentrations. CONCLUSION: Androgen excess in vivo and in vitro comparable to what is present in PCOS increases TNFα release from MNCs of lean healthy reproductive-age women in a receptor-dependent fashion. Hyperandrogenemia activates and sensitizes MNCs to glucose in this population.
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    Intracellular Nef Detected in Peripheral Blood Mononuclear Cells from HIV Patients
    (Mary Ann Liebert, Inc., 2014-07-25) Wang, Ting; Green, Linden A.; Gupta, Samir K.; Amet, Tohti; Byrd, Daniel J.; Yu, Qigui; Twigg, Homer L.; Clauss, Matthias; Department of Microbiology & Immunology, IU School of Medicine
    We report here the novel finding that HIV-negative factor (Nef) protein is present in considerable numbers of peripheral blood mononuclear cells (PBMCs) from viremic HIV-infected patients not on antiretroviral therapy (ART) and also in patients receiving virologically suppressive ART, though to a smaller degree. Interestingly, these Nef-positive PBMCs constitute predominantly uninfected bystander cells. These results may explain systemic pathology in HIV patients, even in those receiving ART.