Effect of leptin on activation and cytokine synthesis in peripheral blood lymphocytes of malnourished infected children

Malnutrition compromises immune function, resulting in reduced resistance to infection. Recent animal and human studies have suggested that leptin is capable of modulating the immune response and that its levels, which are regulated by nutritional status, fall rapidly during starvation. Leptin deficiency is associated with impaired cell-mediated immunity, an increased incidence of infectious disease and an associated increase in mortality. The purpose of this study was to examine the effect of leptin on activation and cytokine production in peripheral blood T cells from malnourished children. The data obtained in the present study demonstrate that leptin produced an increase in the percentage of CD4(+) and CD8(+) cells producing interleukin (IL)-2 and interferon (IFN)-gamma in 24-h cultures. Moreover, leptin decreased the percentage of CD4(+) and CD8(+) cells producing IL-4 and IL-10, and enhanced activation of circulating T cells when co-stimulated by phorbol 12-myristate 13 acetate (PMA)-ionomycin. Leptin enhanced the expression of activation markers CD69 and CD25 in both CD4(+) and CD8(+) cells after 5 h of stimulation. In conclusion, the results obtained show that leptin modulates CD4(+) and CD8(+) cell activation towards a T helper 1 (Th1) phenotype by stimulating the synthesis of IL-2 and IFN-gamma. In contrast, leptin decreases IL-4 and IL-10 production. Moreover, leptin enhanced the expression of CD69 and CD25 on CD4(+) and CD8(+) cells after stimulation with PMA-ionomycin.     

Natural killer cell activation and interferon production by peripheral blood lymphocytes after exposure to bacteria.

We have previously shown that peripheral blood natural killer (NK) cells have significant levels of cytotoxic activity against Shigella flexneri-infected HeLa cells. In this report, we show that NK cell activity against K562 tumor cells and Shigella flexneri-infected HeLa cells can be greatly enhanced by preincubating peripheral blood lymphocytes (PBL) for 18 h with kanamycin-treated Shigella flexneri or Salmonella typhimurium. Cell-free supernatants obtained from PBL-bacteria cultures contained high levels of interferon (IFN) activity, which was characterized as a mixture of IFN-gamma and IFN-alpha. Cytotoxic activity associated with PBL precultured with shigellae was associated with predominantly CD16+ (Leu-11+) and CD2+ (OKT-11+) cells. Further, IFN production was dependent upon the presence of CD16+ and CD2+ cells at culture initiation. Enhancement of cytotoxic activity associated with PBL-bacteria cultures did not, however, appear to be dependent upon IFN production, since low numbers of bacteria which failed to stimulate IFN production induced high levels of NK cell activity. Lipopolysaccharide appeared not to be involved in bacteria-induced IFN production or enhanced NK cell activity, since Salmonella lipopolysaccharide failed to induce IFN production or enhance NK cell activity. These results suggest that IFN production by NK cells and the killing of bacteria-infected cells play an important role in host defense against facultative intracellular bacterial infections.     

Listeria monocytogenes activation of human peripheral blood lymphocytes: induction of non-major histocompatibility complex-restricted cytotoxic activity and cytokine production.

Gram-negative bacteria have been shown to activate human natural killer (NK) cells. In this report, we show that the gram-positive bacterium Listeria monocytogenes can also activate human NK cells with regard to non-major histocompatibility complex (MHC)-restricted killing and the production of cytokines. Overnight incubation of peripheral blood mononuclear (PBM) cells or enriched NK cell populations with live or Formalin-fixed L. monocytogenes resulted in high levels of non-MHC-restricted cytotoxic activity. Listeria-stimulated non-MHC-restricted cytotoxic activity could be achieved with pathogenic as well as nonpathogenic Listeria strains. PBM cells also produced tumor necrosis factor alpha and different interferons (IFNs) after incubation with Listeria strains. Optimal cytokine production appeared to be dependent on nylon wool- and plastic-adherent cells. Different IFNs were produced by Listeria-stimulated PBM cells obtained from different donors. IFN-gamma was always produced but was sometimes associated with IFN-alpha and/or IFN-beta. Interleukin-2 (IL-2) activity was never detected in culture supernatants obtained from Listeria-stimulated PBM cell cultures. However, IL-2 appeared to be produced by Listeria-stimulated PBM cells, since antibody to IL-2 inhibited Listeria-stimulated NK cell cytotoxic activity. Listeria activation of NK cell cytotoxic activity was also dependent on tumor necrosis factor alpha production. Antibody to IFN-gamma, IFN-beta, or IFN-alpha had no effect on Listeria-stimulated NK cell cytotoxic activity. These results demonstrate that NK cells can be activated by Listeria strains and add further evidence that NK cells may play an important role in host defense against bacterial infections.     

Intracellular cytokine production in peripheral blood lymphocytes: a comparison of values in infertile and fertile women

Citation
Horká P, Jaro?ová R, Malí?ková K, Janatková I, Mare?ková H, Zima T, Kalousová M. Intracellular cytokine production in peripheral blood lymphocytes: a comparison of values in infertile and fertile women. Am J Reprod Immunol 2011; 65: 466–469 Problem To analyze the relation of the fertility and pregnancy of women of childbearing age to the intracellular (IC) production of tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), and interleukins 2 and 4 (IL‐2 and IL‐4). Method of study Intracellular cytokine production in peripheral blood CD3⁺ CD4⁺ lymphocytes was analyzed by flow cytometry in 185 women being treated for infertility and 50 fertile women of childbearing age. Results Infertile women have a significantly higher IC production of TNF‐α, IFN‐γ, IL‐2, and IL‐4 and higher ratios of TNF‐α/IL‐2, TNF‐α/IL‐4, and TNF‐α/IFN‐γ compared to the fertile women. Conclusion Cytokines produced by Th lymphocytes are important in orchestrating the immune response during conception, and Th‐cell dysregulation could be a reason for infertility.     

T(H)2 cytokine expression in atopic children with otitis media with effusion

BACKGROUND: The long-term effects of reducing exposure to latex in subjects with latex-induced asthma remain unknown. OBJECTIVE: The purpose of this study was to compare the health and socioeconomic outcomes of subjects with latex-induced asthma before and after reduction or cessation of exposure to latex. METHODS: Thirty-six subjects with latex-induced asthma as ascertained by specific inhalation challenges were investigated after a median follow-up of 56 months (range, 12 to 92 months). Initial and follow-up visits included use of a detailed questionnaire and measurement of the concentration of histamine causing a 20% fall in FEV(1) (PC(20)). At follow-up, information on employment, financial status, and quality of life was collected. RESULTS: At follow-up, 16 subjects were no longer exposed to latex, whereas 20 subjects had reduced exposure. In the subjects who avoided exposure, asthma severity decreased from a median score of 8.5 to 3.5 (P =.001) and the median histamine PC(20) value increased from 0.4 mg/mL to 2.3 mg/mL (P =.002). In the subjects who reduced their exposure, asthma-severity score improved from 6.5 to 2.5 (P <.001) and PC(20) values rose from 0.5 mg/mL to 2.4 mg/mL (P <.001). Cessation of exposure to latex was associated with asthma-related work disability (69%) and loss of income (62%) more frequently than was reduction of exposure (35% and 30%, respectively). CONCLUSION: Reduction of exposure to latex should be considered a reasonably safe alternative that is associated with fewer socioeconomic consequences than removal from exposure.     

Nasopharyngeal secretory immunoglobulins in children with recurrent acute otitis media and secretory otitis media

Secretory IgA (SIgA) and secretory IgM (SIgM), total IgA and total IgM were measured in plasma and nasopharyngeal secretions (NPS) from young children with different degrees of otitis proneness. Significantly higher levels of plasma IgM and lower levels of NPS-SIgM were found in children with recurrent episodes of acute otitis media (rAOM) compared with children suffering from secretory otitis media (SOM) and healthy controls. Both plasma IgA and NPS-SIgA were evenly distributed in the three groups of children investigated, and in most children the levels of NPS-SIgA exceeded plasma IgA levels. Plasma SIgA was significantly increased in children with rAOM and SOM, probably resulting from frequent occurrence of inflammatory events at the nasopharyngeal level. No correlation could be demonstrated between NPS-SIgA and plasma IgA, or between NPS-SIgM and plasma IgM. Also, for both NPS-SIgA and NPS-SIgM, there was no correlation with age. A negative correlation was observed between the transudation index of albumin to the nasopharynx and the ratio of NPS-SIgA to total NPS-IgA. A ratio of 1 (100%) corresponded to a transudation index of 8%. The ratios of NPS-SIgA to total NPS-IgA varied considerably and a range of 39%-88% could only to some extent be explained by transudation of plasma IgA to NPS. The results of the present study show that the children with rAOM and SOM are well furnished with locally produced SIgA antibodies at the nasopharyngeal level. In children with SOM, the nasopharyngeal hypofunction in the case of low NPS-SIgM seems to be less pronounced compared with that of otitis-prone children.     

Subpopulation composition of peripheral blood lymphocytes in children with infectious mononucleosis

In patients with viral and bacterial infectious mononucleosis during the acute period of disease and clinical convalescence blood content of CD72⁺ and CD16⁺ lymphocytes increased compared to normal. The count of CD8⁺ cells increased in viral mononucleosis during convalescence and these changes persist in delayed periods after convalescence. In bacterial mononucleosis the content of CD72⁺ lymphocytes return normal 18 months after convalescence.     

Middle ear fluid cytokine and inflammatory cell kinetics in the chinchilla otitis media model

Streptococcus pneumoniae is the most frequent microbe causing middle ear infection. The pathophysiology of pneumococcal otitis media has been characterized by measurement of local inflammatory mediators such as inflammatory cells, lysozyme, oxidative metabolic products, and inflammatory cytokines. The role of cytokines in bacterial infection has been elucidated with animal models, and interleukin (IL)-1beta, IL-6, and IL-8 and tumor necrosis factor alpha (TNF-alpha) are recognized as being important local mediators in acute inflammation. We characterized middle ear inflammatory responses in the chinchilla otitis media model after injecting a very small number of viable pneumococci into the middle ear, similar to the natural course of infection. Middle ear fluid (MEF) concentrations of IL-1beta, IL-6, IL-8, and TNF-alpha were measured by using anti-human cytokine enzyme-linked immunosorbent assay reagents. IL-1beta showed the earliest peak, at 6 h after inoculation, whereas IL-6, IL-8, and TNF-alpha concentrations were increasing 72 h after pneumococcal inoculation. IL-6, IL-8, and TNF-alpha but not IL-1beta concentrations correlated significantly with total inflammatory cell numbers in MEF, and all four cytokines correlated significantly with MEF neutrophil concentration. Several intercytokine correlations were significant. Cytokines, therefore, participate in the early middle ear inflammatory response to S. pneumoniae.     

Antipolysaccharide antibodies in 450 children with otitis media

We have measured antibodies to pneumococcal and Haemophilus polysaccharides in a prospective study of 450 children aged 2–16 years with otitis media requiring grommets (ear tubes). Pneumococcal antibody levels were significantly higher in the 2–6 year (P < 0.004) and 7–10 year (P < 0.04) study groups in comparison with age-matched controls. There was no difference in Haemophilus antibody levels between the study and control group children for the age groups 2–6 years and 11–16 years. Haemophilus antibody levels were significantly lower in the 7–10 year (P < 0.003) group in comparison with age-matched controls. Eighty-eight out of 450 (19.6%) children had pneumococcal antibody levels below the 25th percentile. Nineteen out of 88 (21.6%) children with pneumococcal antibody levels below the 25th centile were test immunized with 23 valent Pneumococcal polysaccharide and unconjugated Haemophilus type b capsular polysaccharide. Of these 19 children (aged 4–11 years), five mounted suboptimal responses to both polysaccharide antigens, whilst one child failed to respond to Haemophilus polysaccharide alone. There was no significant difference in the prevalence of IgG subclass deficiency between the normal responders and poor responders to immunization (P= 0.12). We found no evidence of specific polysaccharide antibody deficiency in the vast majority of the 450 children studied. However, the significance of poor antibody responses to test immunization in a small minority of children with otitis media is unclear. Long-term follow up of these children is required to determine whether poor immunization responses herald the development of frank antibody deficiency.     

Micronucleus frequencies in peripheral blood lymphocytes of children with chronic kidney disease

One of the crucial adverse effects of chronic kidney disease (CKD) and its treatment is an elevated cancer risk. There are no data on cytogenetic effects in children with CKD or children undergoing dialysis or those who have received a transplant. In this study, cytogenetic effects in children with CKD in pre-dialysis (PreD) stage, on regular haemodialysis (HD) and transplanted (Tx) compared with a control group of healthy children has been investigated using the cytokinesis-blocked micronucleus (CBMN) assay and fluorescence in situ hybridisation (FISH) combined with CBMN (CBMN-FISH) in peripheral blood lymphocytes. The results revealed a significant increase (P < 0.001) in micronucleus (MN) frequencies [mean ± SD (n)] in the PreD, HD and Tx groups versus the control group [CBMN assay; 9.19 ± 2.61 (16), 9.07 ± 4.86 (15), 6.12 ± 5.33 (17) versus 1.60 ± 0.99 (20), respectively]. Moreover, centromere negative micronucleus (C- MN) and centromere positive micronucleus (C+ MN) frequencies were significantly higher in each subgroup children (PreD, HD and Tx) than in the control group (P < 0.01) although children in Tx group had lower C- MN frequencies than PreD and lower C+ MN frequencies than PreD and HD groups (P < 0.05). Additionally, MN frequencies in mononuclear cells, nucleoplasmic bridges and nuclear buds in binucleated cells were increased in children with CKD (P < 0.001, P < 0.001, P > 0.05, respectively). The nuclear division index significantly decreased in Tx group relative to the control, PreD and HD groups (P < 0.001). Associations between cytogenetic parameters and creatinine or blood urea nitrogen were found (P < 0.05). To provide longer and better life expectancy of children with CKD and treatment modes, further research is needed to better understand and avoid these effects.     

Discrepancy between cytokine production from peripheral blood mononuclear cells and nasal secretions among infants with acute bronchiolitis.

BACKGROUND: Many studies have measured cytokine production derived from peripheral blood mononuclear cells (PBMCs) to evaluate the immune response in acute bronchiolitis (AB), but no previous reports have examined the association between PBMC release of cytokines and concomitant airway immune response. OBJECTIVE: To determine whether interferon-gamma (IFN-gamma), interleukin 4 (IL-4), and IL-10 levels from PBMCs are associated with concurrent cytokine release in the airways of infants with AB. METHODS: Infants with acute viral-associated first episode of wheezing who required hospitalization between May and September 2002 were recruited. Nasopharyngeal aspirates (NPAs) and PBMC samples were collected simultaneously. The concentrations of IFN-gamma, IL-4, and IL-10 in NPA and PBMC supernatants were determined by enzyme-linked immunosorbent assay. RESULTS: Twenty infants with AB were enrolled in the study of whom 17 (85%) had positive NPA immunofluorescence results for viral detection and respiratory syncytial virus. Median total cell count and viability from NPA samples were 2.2 x 10(6) cells/mL (SD, 1.7 cells/mL) and 92% (SD, 6.0%), respectively. There was a significant correlation between IL-4 levels from NPA and PBMC samples (r = 0.5, P = .02); however, we did not find an association between IFN-gamma and IL-10 levels. CONCLUSIONS: Cytokines produced by in vitro PBMCs may not necessarily reflect the concurrent cytokine pattern production at the mucosal surface in the respiratory tract of infants with AB. Further studies are required to determine whether peripheral blood is a reliable sample for airway inflammation evaluation and to explain the discrepancies of cytokine productions found in this study.     

Bovine monocytes induce immunoglobulin production in peripheral blood B lymphocytes

Although a role for monocytes and monocyte-derived dendritic cells (DC) in the activation of T cells is well established, it is less clear to what extent DC and their precursors, monocytes, regulate B cell immune responses. Here we show that regulatory mechanisms similar to those in humans are in place in the bovine immune system. In vitro culture of bovine monocytes with bovine B cells activated by the anti-CD3 triggered CD4⁺ T cells or through immunoglobulin (Ig) receptor crosslinking induces B cell Ig secretion. Unlike bovine monocyte-derived DC, monocytes do not promote Ig class switching to IgG and IgA in activated peripheral blood B cells. These results suggest that bovine monocytes are capable of directly inducing Ig secretion in activated bovine peripheral blood B cells, but do not provide the signals for B cell Ig class switching.     

Altered cytokine production by specific human peripheral blood cell subsets immediately following space flight.

In this study, flow cytometry was used to positively identify the specific lymphocyte subsets exhibiting space flight-induced alterations in cytokine production. Whole blood samples were collected from 27 astronauts at three points (one preflight, two postflight) surrounding four space shuttle missions. Assays performed included serum/urine stress hormones, white blood cell (WBC) phenotyping, and intracellular cytokine production following mitogenic stimulation. Absolute levels of peripheral granulocytes were significantly elevated following space flight, but the levels of circulating lymphocytes and monocytes were unchanged. Lymphocyte subset analysis demonstrated a decreased percentage of T cells, whereas percentages of B cells and natural killer (NK) cells remained unchanged after flight. Nearly all the astronauts exhibited an increased CD4/CD8 T cell ratio. Assessment of naive (CD45RA+) vs. memory (CD45RO+) CD4+ T cell subsets was ambiguous, and subjects tended to group within specific missions. Although no significant trend was seen in absolute monocyte levels, a significant decrease in the percentage of the CD14+ CD16+ monocytes was seen following space flight in all subjects tested. T cell (CD3+) production of interleukin-2 (IL-2) was significantly decreased after space flight, as was IL-2 production by both CD4+ and CD8+ T cell subsets. Production of interferon-gamma (IFN-gamma) was not altered by space flight for the CD8+ cell subset, but there was a significant decrease in IFN-gamma production for the CD4+ T cell subset. Serum and urine stress hormone analysis indicated significant physiologic stresses in astronauts following space flight. Altered peripheral leukocyte subsets, altered serum and urine stress hormone levels, and altered T cell cytokine secretion profiles were all observed postflight. In addition, there appeared to be differential susceptibility to space flight regarding cytokine secretion by T cell subsets. These alterations may be the result of either microgravity exposure or the physiologic stresses of landing and readaptation to unit gravity. Future studies, including in-flight analysis or sampling, will be necessary to determine the cause of these alterations.     

Alterations in peripheral blood mononuclear cell cytokine production in response to phytohemagglutinin in multiple sclerosis patients.

Multiple sclerosis (MS) is an autoimmune demyelinating disorder of the central nervous system (CNS). The disease is characterized by inflammatory lesions in the white matter of the CNS, consisting of a specific immune response to the myelin sheath. We investigated peripheral blood mononuclear cell (PBMC) cytokine production by enzyme-linked immunosorbent assays of 21 MS patients and 19 age-matched normal controls in response to the T-cell mitogen phytohemagglutinin (PHA). Peripheral blood mononuclear cells were cultured in medium alone or in medium with 5 micrograms of PHA per ml for 48 h, and culture supernatants were collected for analysis. Cytokines selected for study were interleukin-10 (IL-10), gamma interferon (IFN-gamma), IL-2, and IL-4. All cytokine activities described were expressed as concentrations per 500,000 cells. We found that 48% (10 of 21) of the MS patients produced small but detectable levels of IL-10 in medium alone, compared with 26% (5 of 18) of the controls. We found that the MS patients produced significantly higher quantities of IL-10 protein than the controls in response to PHA (mean supernatant concentrations of IL-10 for patients and controls, 421 and 204 pg/ml, respectively [P < 0.05]). No significant differences were detected in the production of IL-2, IFN-gamma, and IL-4 between patients and controls in response to PHA, although patients appeared to display a trend toward decreased production of IFN-gamma.     

Patterns of food allergen-specific cytokine production by T lymphocytes of children with multiple allergies

BACKGROUND: The contribution of different T cell subsets to the overall measured cytokine response to food allergens is largely unexplored. METHOD: The patterns of cytokine production of peripheral blood-derived T cells after allergen stimulation were studied in 22 children with multiple food allergies and in 20 non-allergic children as controls, using flow cytometry. RESULTS: Proportions of T cells of food-sensitized children spontaneously secreting IFN-gamma and IL-10 (without antigen stimulation) were lower than non-atopic children and adult controls (P相似文献