Simultaneous measurement of six cytokines in a single sample of human tears using microparticle-based flow cytometry: allergics vs. non-allergics

Cysteinyl leukotrienes induce monocyte chemoattractant protein 1 in human monocytes/macrophages

BACKGROUND

Monocytes/macrophages have a cysteinyl leukotriene 1 (CysLT1) receptor, but its function is poorly understood. Objective To elucidate the biological function of the CysLT1 receptor of human monocytes/macrophages.

METHODS

We examined the production of TNF-alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, monocyte chemoattractant protein 1 (MCP-1), macrophage colony-stimulating factor (M-CSF), and eotaxin induced by CysLTs (leukotriene (LT)C4, -D4, and -E4) in THP-1 cells, a human monocytic leukaemia cell line, and peripheral blood CD14+ monocytes/macrophages. Moreover, we examined the effect of CysLTs on the expression of beta-chemokine receptor 2B (CCR2B) as the receptor of MCP-1 by Western blot analysis.

RESULTS

ELISA revealed that CysLTs induced MCP-1 in THP-1 cells and peripheral blood CD14+ monocytes/macrophages, but not other cytokines. PCR demonstrated that CysLTs increased MCP-1 mRNA expression in THP-1 cells, and Western blotting showed that CysLTs increased the expression of CCR2B in THP-1 cells. Moreover, we demonstrated that pranlukast, a CysLT1 receptor antagonist, blocked MCP-1 production by CysLTs in THP-1 cells almost completely, and partially inhibited MCP-1 release by CysLTs in peripheral blood CD14+ monocytes/macrophages and CCR2B expression by CysLTs in THP-1 cells.

CONCLUSION

CysLTs induce MCP-1 and increase CCR2B expression in human monocytes/macrophages.

Reduced type 1 and type 2 cytokines in antiviral memory T helper function among women coinfected with HIV and HCV

Bias in cytokine responses has been proposed as a contributing mechanism to pathogenesis in persistent HIV or hepatitis C virus (HCV) infections. We investigated whether coinfection with HCV modifies the profile of antigen-specific cytokine secretion in women persistently infected with HIV compared to women with single HIV or HCV infection. The T helper response to HIV, HCV and cytomegalovirus (CMV) as a positive viral control was dominated by type 1 cytokines (interleukin- [IL] 2, interferon- [IFN] gamma and tumor necrosis factor- [TNF] alpha), with IFN-gamma as the most abundantly secreted. IL-4, IL-5 and IL-10 were low in healthy controls and patients. Robust CMV-specific responses contrasted with curtailed HCV-specific responses in HCV-infected women. The overall anti-viral profile was dominated by Th1 cytokines even in coinfected women but both type 1 and type 2 responses were reduced in HIV-infected women and more extensively in women with HCV/HIV coinfection.

Validation and comparison of luminex multiplex cytokine analysis kits with ELISA: determinations of a panel of nine cytokines in clinical sample culture supernatants

PROBLEM

Analyses of the expression pattern of multiple cytokines are frequently required for characterization of the status of the immune system as it pertains to Th type bias and intrinsic levels of inflammation. Classically, analysis of cytokine expression patterns has been performed by enzyme-linked immunosorbent assays (ELISA) for each separate analyte. A new technology, Luminex MAP, facilitates the simultaneous evaluation of multiple immune mediators with advantages of higher throughput, smaller sample volume, and lower cost. Validation of this technology has been limited to small sample sets, limited use of clinical study specimens, and use of non-commercial reagents.

METHODS

Ninety-six specimens from women over the course of their respective pregnancies were evaluated for cytokine concentrations using commercially available ELISA kits and commercially available Luminex MAP kits according to the manufacturers' directions. Correlations between data sets were evaluated using Pearson's correlation coefficient (r).

RESULTS

Excellent correlations were demonstrated for IL-1 beta, IL-4, IL-5, IL-6, IL-10, IFN gamma, and TNF alpha, in contrast to IL-12 p 70 and IL-13.

CONCLUSIONS

Luminex multiplex technology has distinct advantages and is a valid alternative method to ELISA for the evaluation of the majority of cytokines tested and for the characterization of immune system status.

Influence of bisphosphonates on the production of pro-inflammatory cytokines by activated human articular chondrocytes

Bisphosphonates have anti-inflammatory effects in rheumatoid arthritis and chondroprotective effects in animal arthritis models but their influence on chondrocytes is not known. The aim of this study is to investigate whether bisphosphonates could influence the production of pro-inflammatory cytokines by activated chondrocytes. Therefore human articular cartilage explants were incubated at 48 h with clodronate, pamidronate or risedronate (10(-6) and 10(-8)mol/L), and dexamethasone (10(-8)mol/L). Subsequently, cultures were stimulated with IL-1, 10 ng/mL (n=6) or 1 ng/mL (n=10) for 48 h. Co-incubation was performed with or without bisphosphonates or dexamethasone. A flow cytometric microsphere-based immunoassay was used for the detection of the pro-inflammatory cytokines IL-6, IL-8, TNF-alpha, IL-1 and the regulatory cytokines IL-12p70 and IL-10 in the supernatants. Stimulation with IL-1 resulted in a dose dependent induction of IL-6 and IL-8, but no production of the other cytokines could be demonstrated. This production of IL-6 and IL-8 was neither inhibited nor enhanced by bisphosphonates. Only dexamethasone caused an inhibition of IL-6 production. In conclusion, there is no evidence on the level of articular cartilage cells that bisphosphonates would suppress or enhance IL-6 and IL-8 mediated joint destruction.

Analysis of cytokine levels in cerebrospinal fluid in mumps meningitis: Comparison with echovirus type 30 meningitis

BACKGROUND

It is unclear whether or not the CSF cytokine profiles in viral meningitis differ with the kind of causative virus.

METHODS

We measured the concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-10 in CSF during the acute stage in 15 children with mumps meningitis (MM), and 34 with echovirus type 30 meningitis (EM).

RESULTS

The CSF IFN-gamma, IL-2, IL-6, and IL-10 levels were elevated in MM, and the CSF IFN-gamma, IL-2, and IL-6 levels were elevated in EM. The CSF IFN-gamma, IL-2, and IL-10 levels in MM were significantly higher than those in EM (p<0.0001, p<0.0001, and p<0.0001, respectively). The CSF IL-6 levels in EM were significantly higher than those in MM (p=0.0255). The CSF TNF-alpha and IL-4 levels were not elevated in MM or EM. In MM, the IL-6 level was correlated with the IL-2 and IL-10 levels in CSF (p=0.0347 and p=0.0120, respectively). In EM, the IFN-gamma level was correlated with the IL-10 level in CSF (p=0.0002).

CONCLUSION

CSF cytokine profiles in MM were different from those in EM. Therefore, it is likely that the pathogenesis of MM is different from that of EM.

Lipopolysaccharide sequestrants: structural correlates of activity and toxicity in novel acylhomospermines

Lipopolysaccharides (LPS), otherwise termed "endotoxins", are outer membrane constituents of Gram-negative bacteria. Lipopolysaccharides play a key role in the pathogenesis of "septic shock", a major cause of mortality in the critically ill patient. Therapeutic options aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide do not exist at the present time. We have defined the pharmacophore necessary for small molecules to specifically bind and neutralize LPS and, using animal models of sepsis, have shown that the sequestration of circulatory LPS by small molecules is a therapeutically viable strategy. In this paper, the interactions of a series of acylated homologated spermine compounds with LPS have been characterized. The optimal acyl chain length for effective sequestration of LPS was identified to be C(16) for the monoacyl compounds. The most promising of these compounds, 4e, binds LPS with an ED(50) of 1.37 muM. Nitric oxide production in murine J774A.1 cells, as well as TNF-alpha in human blood, is inhibited in a dose-dependent manner by 4e at concentrations orders of magnitude lower than toxic doses. Administration of 4e to d-galactosamine-sensitized mice challenged with supralethal doses of LPS provided significant protection against lethality. Potent antiendotoxic activity, low toxicity, and ease of synthesis render this class of compounds candidate endotoxin-sequestering agents of potential significant therapeutic value.

Characterizing biological products and assessing comparability following manufacturing changes

Changes in production methods of a biological product may necessitate an assessment of comparability to ensure that these manufacturing changes have not affected the safety, identity, purity, or efficacy of the product. Depending on the nature of the protein or the change, this assessment consists of a hierarchy of sequential tests in analytical testing, preclinical animal studies and clinical studies. Differences in analytical test results between pre- and post-change products may require functional testing to establish the biological or clinical significance of the observed difference. An underlying principle of comparability is that under certain conditions, protein products may be considered comparable on the basis of analytical testing results alone. However, the ability to compare biological materials is solely dependent on the tests used, since no single analytical method is able to compare every aspect of protein structure or function. The advantages and disadvantages of any given method depends on the protein property being characterized.

Tear cytokines in acute and chronic ocular allergic inflammation

PURPOSE OF REVIEW

Elevated levels of inflammatory cytokines have been reported in tears from ocular allergic disease states. The purpose of this review is to assimilate recent research contrasting tear cytokine concentrations in non-allergic subjects versus subjects with acute (seasonal allergic conjunctivitis) and chronic (giant papillary conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis) ocular allergic inflammation to discover whether the cytokine profiles could provide useful insight into disease mechanisms and therapeutic targets.

RECENT FINDINGS

Recent studies have revealed distinct differences in the cytokine/chemokine concentrations in tears between the various manifestations of ocular allergy. The acute (seasonal allergic conjunctivitis) and iatrogenic (giant papillary conjunctivitis) forms of ocular allergic inflammation are characterized by an overall lack of significant cytokine changes in tears compared with chronic disease (vernal keratoconjunctivitis, atopic keratoconjunctivitis). Chronic ocular allergic inflammation produces increased concentrations of T helper 1 and 2, and proinflammatory cytokines as well as chemokines. However, vernal and atopic keratoconjunctivitis portray distinct differences in the patterns of tear cytokines/chemokines expressed.

SUMMARY

The plethora of increased cytokines and chemokines in vernal and atopic keratoconjunctivitis compared with non-allergic, seasonal allergic conjunctivitis and giant papillary conjunctivitis provides a new perspective into the complex inflammatory processes occurring on the ocular surface in chronic disease. The ability to measure multiple cytokines in tears, combined with knowledge obtained from in-vitro analysis of the individual and combined effects of these cytokines on various conjunctival cells (i.e. mast cells, epithelial cells, fibroblasts) has facilitated further understanding of specific processes contributing to maintenance of inflammation and progression of vision-threatening disease and paved the way toward new therapeutic targets.

Analysis of cytokine levels and NF-kappaB activation in peripheral blood mononuclear cells in influenza virus-associated encephalopathy

BACKGROUND

Influenza virus-associated encephalopathy (IE) is suggested to be a proinflammatory cytokine-related disease.

METHODS

We measured the concentrations of interleukin-6 (IL-6), TNF-alpha, soluble TNF receptor 1 (sTNFR1), IL-10, interferon-gamma, IL-2, IL-4, and soluble E-selectin (sE-selectin) in serum and CSF during the acute stage in 30 children with IE, 20 with influenza virus-associated febrile seizures (IFS), and 39 with influenza virus infection without complications (Flu). Moreover, the activation of transcription factor NF-kappaB in peripheral blood mononuclear cells (PBMC) of 5 children with IE was examined.

RESULTS

The serum IL-6, sTNFR1, and IL-10 levels in the IE group with a poor prognosis (Group A) were significantly higher than those in the IE group without sequelae in IE (Group B), IFS, and Flu. In particular, the serum levels of IL-6, sTNFR1, and IL-10 in 5 deceased patients were markedly higher. The CSF IL-6 levels in Group A were significantly higher than those in Group B and IFS. Flow cytometric analysis revealed that NF-kappaB activation in PBMC in Group A was higher than that in Group B, IFS, and Flu.

CONCLUSION

We suggest that cytokines are produced by PBMC in IE, and that the levels of serum IL-6, sTNFR1, and IL-10, CSF IL-6, and NF-kappaB activation in PBMC are useful indicators of the severity of the disease.

Signal transduction of erbB receptors in trastuzumab (Herceptin) sensitive and resistant cell lines: Local stimulation using magnetic microspheres as assessed by quantitative digital microscopy

BACKGROUND

ErbB2 (HER-2), a member of the epidermal growth factor (EGF) receptor family, is a class I transmembrane receptor tyrosine kinase. Although erbB2 has no known physiologic ligand, it can form complexes with other members of the family and undergo transactivation of its very potent kinase activity, thereby initiating downstream signaling and cell proliferation. ErbB2 is a frequent pathologic marker in ductal invasive breast carcinomas and is targeted by using a specific humanized monoclonal antibody, trastuzumab (Herceptin). The antibody is effective in only 20% to 50% of erbB2-positive tumors, and this resistance, as yet poorly understood, constitutes a major therapeutic challenge.

METHODS

Magnetic microspheres coated with ligands or antibodies are widely used for separation of proteins and cells and allow localized, high intensity, and precisely timed stimulation of cells. We used EGF- and trastuzumab-covered paramagnetic microspheres, quantitative confocal laser scanning microscopy, and digital image processing to investigate the (trans)activation of and local signal propagation from erbB1 and erbB2 on trastuzumab sensitive and resistant carcinoma cell lines expressing these receptors at high levels.

RESULTS

On A431 cells expressing high levels of endogenous erbB1 and transfected erbB2-mYFP (A4-erbB2-mYFP F4 cell line), EGF-coupled-microspheres activated erbB1 and transactivated erbB2-mYFP. In two other cell lines with comparable erbB2 expression but lower levels of erbB1, EGF microspheres transactivated erbB2 less efficiently. Trastuzumab in solution activated erbB2 on A4-erbB2-mYFP and the trastuzumab sensitive SKBR-3 cells, but only negligibly on the resistant JIMT-1 cells that showed a 10 times higher K(d) for the antibody. Nevertheless, pronounced erbB2 activation and tyrosine phosphorylation could be detected after stimulation with trastuzumab-coupled microspheres in all cell lines, although transactivation of erbB1 was negligible. Receptor phosphorylation was restricted to the immediate proximity of the microspheres, i.e., receptor clusters external to these locations remained inactive.

CONCLUSION

ErbB1 ligand and erbB2 specific antibody attached to magnetic microspheres are efficient tools in assessing erbB activation, localized signal propagation, and erbB heterodimer formation. Trastuzumab coupled to microspheres is more efficient at accessing erbB2 and activating it than trastuzumab in solution.

CD200 maintains microglial potential to migrate in adult human retinal explant model

PURPOSE

Retinal microglia (MG) migrate in response to injury, degeneration and inflammation dependent upon both soluble and cognate signals they receive. Previously we found that lipopolysaccharide/interferon-gamma (LPS/IFNgamma) stimulation induces a paradoxical IL-10 mediated suppression of MG migration from retinal explants. Given the high expression of neuronal CD200, which can induce down regulation of CD200 receptor-positive MG activation and neuronal fractalkine expression potentially stimulating MG migration, we wished to further examine their respective roles in the maintenance of MG activation and migration.

METHODS

A human retinal explant model of MG migration was used. CD200 receptor and fractalkine receptor stimulation was achieved by addition to explants of CD200:Fc fusion protein and recombinant cytokine respectively, with or without LPS-IFNgamma stimulation that is known to suppress migration. Cell migration and cell activation (iNOS expression) was counted and assessed by numbers of CD45+ cells by immunofluorescence and standardised flow cytometric bead array analysis was performed for cytokine production.

RESULTS

Retinal explants expressed fractalkine and CX3CR1 immunohistochemically and by PCR. Addition of Fractalkine and not CD200:Fc induced MG migration from retinal explants. However LPS/IFNgamma-induced suppression of MG migration could only be restored in the presence of CD200:Fc, whilst MG remained iNOS-negative and generated IL-10.

CONCLUSIONS

Microglial responses are tightly governed within retina. Although MG do not classically activate following LPS/IFNgamma stimulation, their migration is sustained via CD200R stimulation maintaining their potential to migrate in response to injury.

Commercially available antibodies to human tumour necrosis factor-alpha tested for cross-reactivity with ovine and bovine tumour necrosis factor-alpha using flow cytometric assays

A thorough understanding of the immune system, including the role of different cytokines, during inflammatory diseases in ruminants could lead to the development of new diagnostic methods and treatments. Tumour necrosis factor-α (TNF-α) is an important cytokine in the onset of the inflammatory responses. Unfortunately, the number of studies on cytokines, like TNF-α, in ruminants is limited due to a lack of species-specific reagents. As cytokines have remained rather conserved during evolution, cross-reactivity between animal species may occur. Therefore, the aim of the present study was to investigate 5 commercially available antibodies against human TNF-α for their ability to cross-react with ovine and/or bovine TNF-α, using a bead-based flow cytometric method. Two of the antibody clones (Mab 11 and 6401.1111) showed cross reactivity with ovine recombinant TNF-α in concentrations above 2.5 ng/ml. However, none of the antibodies detected TNF-α in bovine milk, or serum containing known concentrations of bovine TNF-α, as earlier determined with ELISA. The results could be due to inability of the antibodies to cross-react between species, but quenching of the signal by matrix proteins might also have lowered the response.

Cutting edge: engagement of CD160 by its HLA-C physiological ligand triggers a unique cytokine profile secretion in the cytotoxic peripheral blood NK cell subset

CD160 is an Ig-like activating NK cell receptor expressed on the majority of circulating NK cells. This population corresponds to the nonproliferating, highly cytolytic, CD56dimCD16+ subset. CD160 engagement by HLA-C molecules mediates cytotoxic function. In this study, we report that upon specific activation by the physiological ligand HLA-C, or Ab cross-linking, CD160+ peripheral blood NK cells produce IFN-gamma, TNF-alpha, and IL-6. This unique CD160-mediated cytokine production differs from the one observed after CD16 engagement whose expression is also restricted to the CD56dim cytotoxic NK cell subset. As already reported for the CD160-mediated cytotoxic effector function, CD160-mediated cytokine production by peripheral blood-NK cells is negatively controlled by the killer Ig-like receptor CD158b. Thus, the CD160 receptor represents a unique triggering surface molecule expressed by cytotoxic NK cells that participates in the inflammatory response and determines the type of subsequent specific immunity.

A novel method for simultaneous analysis of specific platelet antibodies: SASPA

Glycoprotein (GP)-specific platelet antibodies can cause allo-immune and auto-immune thrombocytopenia. The specific detection of relevant antibodies is a prerequisite for diagnosis and treatment. Here, we describe an improved method based on simultaneous detection of various platelet-specific immunoglobulin G (IgG) and IgM antibodies. Bead populations with distinct fluorescence intensities, coated with monoclonal antibodies specific for mouse heavy chain isotypes, were used for the simultaneous immobilization of platelet-GP [IIb/IIIa, Ib/IX, human leucocyte antigen (HLA) class I, or Ia/IIa, CD32, GPIV or CD109, Ib/IX, HLA class I]. In order to detect human IgG and IgM antibodies simultaneously, phycoerythrin- and fluorescein isotiocyanate-conjugated goat anti-human IgG and IgM were added. On this basis, the abundance of six distinct antibodies (three anti-GP, each with subclasses IgG and IgM) were simultaneously analysed without cross-reaction by flow cytometry. For evaluation, sera and platelets from 169 patients with platelet-binding and/or platelet-associated antibodies were investigated. The monoclonal antibody-specific immobilization of platelet antigen (MAIPA) assay was performed in parallel as reference test. The simultaneous analysis of platelet-specific antibodies (SASPA) assay was able to detect all platelet-specific IgG and IgM that were also recognized by MAIPA with a comparable sensitivity. SASPA proved to be a rapid and reliable assay that required less platelets than other methods. This method has the potential to pave the way for new investigations of platelet-specific antibodies.

Roles of Chemokines in Ocular Allergy and Possible Therapeutic Strategies

The mechanism of ocular surface allergy in the forms of atopic conjunctivitis and vernal keratoconjunctivitis has been highlighted by specific functions of chemokines. In the context of late-phase allergic responses, these molecules have key roles in recruitment and activation of leukocytes. Their interaction with ligands is redundantly regulated; however, results from strategies to block subsets of chemokines have revealed unexpected or highly organized roles of these mediators. Exemplified by analyses of CCL11 function, current concepts of ocular allergy support CCL11 as central mediator. We emphasize the functions as modulator of mast cell activation/differentiation. With the prospect of understanding these functions, new modalities of drugs specifically developed to target CCL11/CCR3 interaction have been discussed.

Endotracheal colonization at birth is associated with a pathogen-dependent pro- and antiinflammatory cytokine response in ventilated preterm infants: a prospective cohort study

The possible association between mediators of inflammation such as cytokines and perinatal colonization of the respiratory tract remains unclear. This prospective cohort study evaluated endotracheal colonization in 141 ventilated preterm infants at birth. The relation with cytokine response in the airways and C-reactive protein (CRP) in umbilical blood was investigated. Of the 141 preterm infants enrolled in this study, 37 (26%) were colonized. In addition to traditional pathogens (61%), commensal species (26%) and Mycoplasmataceae (13%) were isolated. Both the pro-inflammatory cytokines IL-1 beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha as well as the antiinflammatory IL-10 are increased in colonized patients in a dose-dependent manner, with the strongest response in neonates colonized with Gram-negative organisms. There was no antimicrobial IL-12p70 response in colonized infants. Commensal flora is associated with the same inflammatory response as traditional pathogens. Although the umbilical cord blood CRP level was significantly higher in neonates with endotracheal colonization, it was highest in those colonized with Gram-negative organisms but still close to normal limits. Microorganisms in the endotracheal fluid of ventilated preterm infants are associated with a pathogen-specific and dose-dependent cytokine response in the airways and systemic CRP response.

Rapid simultaneous measurement of multiple cytokines using 100 microl sample volumes--association with neonatal sepsis

Early diagnosis of neonatal infection has proved problematic due to the inadequacy of currently available laboratory tests. Neonatal sepsis is associated with an increase in plasma-derived cytokine levels, but an increase of a single cytokine cannot identify neonatal sepsis specifically and multiple cytokine levels are required. The time constraints and relatively large volume of plasma required to measure multiple cytokines from newborn infants by conventional enzyme-linked immunosorbent assay (ELISA) techniques is prohibitive. We therefore applied cytometric bead array (CBA) technology for simultaneous measurement of multiple cytokines from a group of 18 term neonates with infection confirmed by culture and a control group. 'Normal' ranges were established for each cytokine from 1-7-, 8-14- and 15-21-day-old newborns. There was no significant change in the levels of cytokines from infants in different control age groups, suggesting that basal cytokine levels are unchanged in the first 3 weeks of life. In the patient groups, however, there was a significant difference in several cytokines between the different age groups. Interleukin (IL)-6, IL-10 and IL-12 were increased significantly in the 1-7-day-old patient group compared to either the 8-14 and 15-21 age group, suggesting that infection in utero is associated with increased levels of these cytokines compared to infection acquired following birth. When individual patient cytokine levels were compared to normal control reference ranges, two patients failed to show significant elevation of any cytokine tested. All other patients showed elevated levels of between one and nine cytokines tested (mean of 4.6). There was no correlation between elevated cytokine levels and types of infective organism or patient age. In conclusion, neonatal sepsis is associated with the elevation of multiple plasma cytokines. The use of CBA kits is a rapid, easy, low sample volume and sensitive method to measure multiple plasma cytokines.

A Simplified Cytokine Immunoassay Using Magnetic Polymer Particles

Accurate detection of cytokines is essential for understanding their biological role in the immune system. Various methods to detect cytokines have been developed, including sandwich enzyme-linked immunosorbent assay (ELISA) and flow cytometry-based methods. All of the currently available methods have limitations, however. These limitations include time and extensive handling in standard sandwich ELISAs and the need for specialized equipment in flow cytometry-based assays. We have developed a magnetic polymer cytokine immunoassay and demonstrate that this assay is rapid and simple, needs less handling and offers better dynamic range, compared to standard sandwich ELISA. Furthermore, it does not require flow cytometry equipment, which is often used in microparticle-based polymer immunoassays. The magnetic polymer cytokine immunoassay described in this study is as sensitive as a standard sandwich ELISA. Because the method is not limited to the use of magnetic polymer particles, it is versatile and compatible with a number of different solid matrixes.

Lachrymal Determinations: Methods and Updates on Biopharmaceutical and Clinical Applications

This article displays different procedures used to collect lachrymal fluid and describes some of its applications. Sampling tears represents the main difficulty to produce precise and reproducible results. The direct sampling procedure consists in collecting tears with capillary tubes and has the drawback of demanding previous stimulation that induces major dilution. The indirect method does not require preliminary stimulation but has been held responsible for altering epithelium and promoting leakage from plasma. Schirmer strips and sponges are classically required. Applications are numerous in biopharmaceutical and clinical fields. The determination of endogenous components has great potentiality as a diagnostic tool, but the use of tear as a substitute of plasma does not present clinical relevance. Levels of drugs like immunosuppressive or antibiotic agents are determined in tears to verify that pharmacological concentrations are reached and frequency of administration is deduced from kinetic fitting.

Validation and comparative analysis of a multiplexed assay for the simultaneous quantitative measurement of Th1/Th2 cytokines in human serum and human peripheral blood mononuclear cell culture supernatants

There is increasing evidence suggesting a relationship between cytokine levels and disease pathogenesis, which has led to interest in analyzing multiple cytokines in biological fluids and culture supernatants for various research and clinical studies. The introduction of methodologies allowing simultaneous measurement of interrelated biomarkers/cytokines has further revolutionized this process. In contrast to tissue culture supernatant, the measurement of cytokines in serum has proven to be difficult to characterize in multiplexed formats because of the presence of large dynamic concentration ranges of proteins and other interfering factors that are present in this matrix. In the present study, we have used the microsphere-based multiplex method to simultaneously quantitate and compare six analytes, encompassing a representation of the Th1/Th2 cytokine panel (interleukin (IL)-2, IL-4, IL-5, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and IL-10), in both serum and culture supernatants from peripheral blood mononuclear cells (PBMCs). A detailed validation procedure for these determinations is described along with a comparative analysis of the performance of the multiplexed assay in serum and culture supernatant matrices. Our results indicate that precision of the multiplexed assay is comparable in both culture supernatant and serum. However, the accuracy of quantification of cytokines in the serum matrix but not in culture supernatant may be compromised depending upon the cytokine being analyzed. Therefore, one must use caution when interpreting data from such complex matrices. Nevertheless, this assay format is appropriate to profile cytokines in clinical trial samples.

HIV infection of naturally occurring and genetically reprogrammed human regulatory T-cells

A T-cell subset, defined as CD4(+)CD25(hi) (regulatory T-cells [Treg cells]), was recently shown to suppress T-cell activation. We demonstrate that human Treg cells isolated from healthy donors express the HIV-coreceptor CCR5 and are highly susceptible to HIV infection and replication. Because Treg cells are present in very few numbers and are difficult to expand in vitro, we genetically modified conventional human T-cells to generate Treg cells in vitro by ectopic expression of FoxP3, a transcription factor associated with reprogramming T-cells into a Treg subset. Overexpression of FoxP3 in naïve human CD4(+) T-cells recapitulated the hyporesponsiveness and suppressive function of naturally occurring Treg cells. However, FoxP3 was less efficient in reprogramming memory T-cell subset into regulatory cells. In addition, FoxP3-transduced T-cells also became more susceptible to HIV infection. Remarkably, a portion of HIV-positive individuals with a low percentage of CD4(+) and higher levels of activated T-cells have greatly reduced levels of FoxP3(+)CD4(+)CD25(hi) T-cells, suggesting disruption of the Treg cells during HIV infection. Targeting and disruption of the T-cell regulatory system by HIV may contribute to hyperactivation of conventional T-cells, a characteristic of HIV disease progression. Moreover, the ability to reprogram human T-cells into Treg cells in vitro will greatly aid in decoding their mechanism of suppression, their enhanced susceptibility to HIV infection, and the unique markers expressed by this subset.

Immunoregulatory defects of V alpha 24V+ beta 11+ NKT cells in development of Wegener's granulomatosis and relapsing polychondritis

The frequency of either CD4(-)8(-) (double negative; DN) or CD4(+) V alpha 24(+)V beta 11(+) NKT cells, the expression of CD1d and the binding of CD1d-tetramer loaded with alpha-galactosylceramide (alpha-GalCer) to NKT cells were analysed in peripheral blood mononuclear cells (PBMCs) of patients with Wegener's granulomatosis (WG), relapsing polychondritis (RP) and healthy subjects (HS). DN and CD4(+) V alpha 24(+)V beta 11(+) NKT cells as well as CD1d-alpha-GalCer tetramer-positive NKT cells, were significantly decreased in number in both WG and RP patients compared to those from HS. When cytokine profiles were analysed in these PBMCs upon stimulation with phorbol ester and calcium ionophore, CD4(+) T cells from patients with WG and RP exhibited a Th1 bias, whereas CD4(+) NKT cells from WG patients in remission showed a Th2 bias. These findings suggest that NKT cells (especially CD4(+) NKT cells) play a regulatory role in Th1 autoimmunity in patients with WG and RP. The reduction in NKT cell counts appears to be associated with the low responsiveness to alpha-GalCer. The dysfunction of NKT cells to recognize ligands such as alpha-GalCer may also contribute to the defects observed in NKT cells from WG and RP patients.

Cytokine secretion in nasal mucus of normal subjects and patients with allergic rhinitis

Allergic rhinitis is regulated by the local production and release of several cytokines. The levels of Th2 cytokines IL-4, IL-6, IL-10 and the Th1 cytokine IFN-gamma were studied in nasal mucus from 30 subjects with allergic rhinitis and 45 non-atopic healthy controls. In this study a sampling technique for collecting nasal mucus, well tolerated by the subjects and with a minimal stimulation of the mucosa, was performed. The cytokine concentrations in nasal mucus samples were detected and quantitated by a new paramagnetic particle-based immunofluorescent assay system more sensitive than the conventional ELISA techniques. The new technique showed reliable values of the measured parameters. The nasal mucus from allergic patients contained significantly higher concentrations of IL-4 (25.5 +/- 3.6 pg/ml; P < 0.001) and IL-10 (1300 +/- 190 pg/ml; P < 0.05) compared to the nasal mucus from control subjects (15.2 +/- 2.3 and 532 +/- 28 pg/ml, respectively, for IL-4 and IL-10). No significant modification in IFN-gamma levels of allergic patients was found when compared to control group (respectively, 19.9 +/- 3.3 vs. 25.7 +/- 5.1 pg/ml; P > 0.05). Moreover, the allergic patients showed lower levels of IL-6 concentrations in the nasal mucus compared to control subjects (64.8 +/- 9.1 vs. 129.0 +/- 18.1 pg/ml; P = 0.0099). These data can be interpreted by the hypothesis that in response to environmental allergens there is a preferential Th2 polarity by activated CD4+ T cells and that the cytokines IL-6 and IL-10 have, respectively, an important anti-inflammatory and counterregulatory action in the pathogenesis of allergic rhinitis.

Perspectives and limitations of gene expression profiling in rheumatology: new molecular strategies

The deciphering of the sequence of the human genome has raised the expectation of unravelling the specific role of each gene in physiology and pathology. High-throughput technologies for gene expression profiling provide the first practical basis for applying this information. In rheumatology, with its many diseases of unknown pathogenesis and puzzling inflammatory aspects, these advances appear to promise a significant advance towards the identification of leading mechanisms of pathology. Expression patterns reflect the complexity of the molecular processes and are expected to provide the molecular basis for specific diagnosis, therapeutic stratification, long-term monitoring and prognostic evaluation. Identification of the molecular networks will help in the discovery of appropriate drug targets, and permit focusing on the most effective and least toxic compounds. Current limitations in screening technologies, experimental strategies and bioinformatic interpretation will shortly be overcome by the rapid development in this field. However, gene expression profiling, by its nature, will not provide biochemical information on functional activities of proteins and might only in part reflect underlying genetic dysfunction. Genomic and proteomic technologies will therefore be complementary in their scientific and clinical application.

Flow cytometry for natural killer T cells: multi-parameter methods for multifunctional cells

Valpha24-Jalpha18 invariant natural killer T cells (iNKT) are an evolutionary conserved sub-lineage of T cells with effector-memory phenotype that often express an NK cell surface antigen CD161 and is characterized by reactivity to self-glycolipids and alpha-galactosylceramide (alphaGalCer) that are presented by monomorphic HLA class-I-like molecule CD1d. Upon antigen recognition, iNKT cells can rapidly produce multiple cytokines and chemokines and regulate development of Th-2 and Th-1 immune responses. Potential importance of iNKT cells has been demonstrated in several animal models of infection diseases, autoimmunity, and cancer. Multi-parameter flow cytometry has been the main tool to study human and murine iNKT cells. Analysis of human iNKT cells is particularly demanding since their frequency among peripheral blood T cells is relatively low ranging from less than 0.01% to 1%, with a mean of about 0.1%. Herein, we discuss flow cytometry applications that are utilized for iNKT cell identification and enumeration, subset characterization, detection of intracellular cytokines, quantitative analysis of multiple secreted molecules, cell-mediated cytotoxicity, and migration.

No apparent association between periocular and ocular microcolonization and the degree of inflammation in patients with atopic keratoconjunctivitis

BACKGROUND

The cause of the chronic inflammation in atopic keratoconjunctivitis (AKC), the ocular manifestation of atopic eczema/dermatitis syndrome, is largely unknown.

OBJECTIVE

To investigate the possibility that microorganisms may be important in the inflammatory activity in AKC.

METHODS

Fifteen patients with AKC participated in the study. The presence of aerobic bacteria and fungi was related to the severity of clinical signs, the numbers of inflammatory cells in tears and conjunctival biopsies, and the concentration of various cytokines in tears. In addition, serological evidence for IgE sensitization to Staphylococcus aureus B antigen and Malassezia sympodialis antigen was investigated. Twelve healthy subjects were included for control purposes.

RESULTS

The patients exhibited moderate clinical signs of AKC. No relation was found between the severity of AKC and the presence of microorganisms, despite the fact that S. aureus was frequently isolated. AKC patients showed significantly higher levels of IFN-gamma, TNF-alpha (tumour necrosis factor-alpha), IL-2, IL-4, IL-5 and IL-10 than controls. An association was found between conjunctival signs and the levels of all cytokines except IL-5.

CONCLUSION

We found no evidence to suggest that periocular and ocular microcolonization are related to inflammatory parameters in AKC. However, confirmation of the present results in a longitudinal study with repeated clinical examinations and samplings in the same individual is required before the contribution of S. aureus to on-going inflammation in AKC can be dismissed.

Systemic CD4(+) T cell phenotype and activation status in intermediate uveitis

AIM

To investigate peripheral blood lymphocyte phenotype in patients with intermediate uveitis using CD69, chemokine receptor, and cytokine expression.

METHODS

Peripheral blood lymphocytes of 18 patients with idiopathic intermediate uveitis and 6 patients with presumed sarcoid intermediate uveitis were evaluated for CD4(+) T cell expression of CD69, CCR4, CCR5, CXCR3 and the intracellular cytokines IFNgamma, TNFalpha, and interleukin (IL)-10 by flow cytometry, and for IL-2, IL-4, IL-5, IL-10, IFNgamma, and TNFalpha production following unstimulated and activated culture using cytokine bead array and compared with healthy control subjects.

RESULTS

The expression of CD69 and TNFalpha by peripheral blood CD4(+) lymphocytes of patients with idiopathic intermediate uveitis and presumed sarcoid intermediate uveitis was significantly higher than control subjects (p = 0.002 and p<0.05, respectively). The ratios of the concentrations of IL-2:IL-5 and IFNgamma:IL-5 in supernatants of activated peripheral blood lymphocyte cultures were significantly higher in patients with presumed sarcoid intermediate uveitis than control subjects.

CONCLUSIONS

This study implicates TNFalpha in the pathogenesis of intermediate uveitis, highlighting the potential role of anti-TNF treatments for this disease. Studies of Th1:Th2 cytokine ratios suggested polarisation of the immune response towards Th1 in presumed sarcoid intermediate uveitis despite clinically quiescent systemic disease.

Cytometric bead array: a multiplexed assay platform with applications in various areas of biology

The introduction of flow cytometric bead-based technology has added a new approach for investigators to simultaneously measure multiple analytes in biological and environmental samples. This new technology allows for (1) evaluation of multiple analytes in a single sample; (2) utilization of minimal sample volumes to glean data; (3) reproducibility and results comparative with previous experiments; (4) direct comparison with existing assays; and (5) a more rapid evaluation of multiple samples in a single platform. The cytometric bead array (CBA) system enables simultaneous measurement of multiple analytes in sample volumes too small for traditional immunoassays. Results have been presented for the analysis of a variety of human cytokines. In addition, the technology allows for the design and creation of assays to measure a variety of analytes including inflammatory mediators, chemokines, immunoglobulin isotypes, intracellular signaling molecules, apoptotic mediators, adhesion molecules, and antibodies. New initiatives put forward by the Human Genome Project and the FDA require the development and use of assays for the rapid simultaneous quantitation of multiple analytes. The CBA technology provides the ability to quantify multiple proteins within a given sample, with precision and consistency.

Infection of primary human macrophages with hepatitis C virus in vitro: induction of tumour necrosis factor-alpha and interleukin 8

Hepatitis C virus (HCV) has been reported to replicate in monocytes/macrophages in infected patients. However, it is unclear whether macrophages are susceptible to infection in vitro and whether such an infection is consequential. Sera from 26 HCV-infected patients were incubated with primary human macrophages collected from healthy donors. Virus negative strand was detected by a Tth enzyme-based strand-specific assay and virus sequences were analysed by single strand conformation polymorphism (SSCP) and sequencing. Concentrations of the cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta, IL-6, IL-8, IL-10 and IL-12p70 were measured in culture supernatants and respective mRNAs were analysed in cell extracts by quantitative RT-PCR. For 15 sera, HCV RNA was detectable in 2- and 3-week cultures from at least one donor. Virus negative strand was detected in 29 % of macrophage samples in this group. In four cases, HCV RNA sequences amplified from macrophages differed from those amplified from sera suggesting evolution during infection. Concentrations of TNF-alpha and IL-8 were found to be significantly higher in supernatants from HCV-infected cultures. In conclusion, these preliminary data suggest that primary human macrophages are susceptible to HCV infection in vitro and this infection is associated with the induction of cytokines TNF-alpha and IL-8.

Novel and detrimental effects of lipopolysaccharide on in vitro generation of immature dendritic cells: involvement of mitogen-activated protein kinase p38

Dendritic cells (DCs) are recognized as major players in the regulation of immune responses to a variety of Ags, including bacterial agents. LPS, a Gram-negative bacterial cell wall component, has been shown to fully activate DCs both in vitro and in vivo. LPS-induced DC maturation involves activation of p38, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases, and NF-kappaB. Blocking p38 inhibits LPS-induced maturation of DCs. In this study we investigated the role of LPS in the in vitro generation of immature DCs. We report here that in contrast to the observed beneficial effects on DCs, the presence of LPS in monocyte culture retarded the generation of immature DCs. LPS not only impaired the morphology and reduced the yields of the cultured cells, but also inhibited the up-regulation of surface expression of CD1a, costimulatory and adhesion molecules. Furthermore, LPS up-regulated the secretion of IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha; reduced Ag presentation capacity; and inhibited phosphorylation of ERK, but activated p38, leading to a reduced NF-kappaB activity in treated cells. Neutralizing Ab against IL-10, but not other cytokines, partially blocked the effects of LPS. Inhibiting p38 (by inhibitor SB203580) restored the morphology, phenotype, and Ag presentation capacity of LPS-treated cells. SB203580 also inhibited LPS-induced production of IL-1beta, IL-10, and TNF-alpha; enhanced IL-12 production; and recovered the activity of ERK and NF-kappaB. Thus, our study reveals that LPS has dual effects on DCs that are biologically important: activating existing DCs to initiate an immune response, and inhibiting the generation of new DCs to limit such a response.

Genetic reprogramming of primary human T cells reveals functional plasticity in Th cell differentiation

Activation of naive T cells through the TCR and cytokine signals directs their differentiation into effector or memory subsets with different cytokine profiles. Here, we tested the flexibility of human Th1 or Th2 differentiation by forced expression of transcription factors T-bet and GATA-3. Ectopic expression of T-bet and GATA-3 in freshly isolated human T(N) cells resulted in their differentiation to a Th1 and Th2 phenotype, respectively, in the absence of polarizing cytokines. Introduction of GATA-3 into lineage-committed Th1 cells induced the expression of Th2-specific cytokines (IL-4 and IL-5) and chemotactic receptors (CCR4, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). However, these cells partially maintained their Th1-specific profile (IFN-gamma and IL-12Rbeta2 expression). Conversely, expression of T-bet in lineage-committed Th2 cells caused a more profound switch to the Th1 phenotype, including the up-regulation of CXCR3 and down-regulation of CCR4 and CRTH2. Interestingly, similar to the naive T cell subset, central memory T cells were also largely programmed toward Th1 or Th2 effector cells upon expression of T-bet and GATA-3, respectively. However, expression of these transcription factors in effector memory T cells was much less influential on cytokine and chemokine receptor expression profiles. Our results reveal remarkable plasticity in the differentiation programs of human memory T cells. This flexibility is progressively diminished as cells mature from naive to effector T cells. These findings have important implications in understanding the molecular mechanisms of human T cell differentiation and for devising novel therapeutic strategies aimed at immunomodulation of skewed effector T cell responses.

Muscle force during an acute exacerbation in hospitalised patients with COPD and its relationship with CXCL8 and IGF-I

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is often associated with peripheral muscle weakness, which is caused by several factors. Acute exacerbations may contribute, but their impact on muscle force remains unclear. Correlations between peripheral muscle force and inflammatory and anabolic markers have never been studied in COPD. The effect of an acute exacerbation on quadriceps peak torque (QPT) was therefore studied in hospitalised patients, and the aforementioned correlations were examined in hospitalised and in stable patients.

METHODS

Lung function, respiratory and peripheral muscle force, and inflammatory and anabolic markers were assessed in hospitalised patients on days 3 and 8 of the hospital admission and 90 days later. The results on day 3 (n=34) were compared with those in clinically stable outpatients (n=13) and sedentary healthy elderly subjects (n=10).

RESULTS

Hospitalised patients had lowest mean (SD) QPT (66 (22)% predicted) and highest median (IQR) levels of systemic interleukin-8 (CXCL8, 6.1 (4.5 to 8.3) pg/ml). Insulin-like growth factor I (IGF-I) tended to be higher in healthy elderly subjects (p=0.09). QPT declined between days 3 and 8 in hospital (mean -5% predicted (95% CI -22 to 8)) and partially recovered 90 days after admission to hospital (mean 6% predicted (95% CI -1 to 23)). QPT was negatively correlated with CXCL8 and positively correlated with IGF-I and lung transfer factor in hospitalised and in stable patients.

CONCLUSIONS

Peripheral muscle weakness is enhanced during an acute exacerbation of COPD. CXCL8 and IGF-I may be involved in the development of peripheral muscle weakness in hospitalised and in stable patients with COPD.

CD4+ Th cells resembling regulatory T cells that inhibit chronic colitis differentiate in the absence of interactions between CD4 and class II MHC

Regulatory CD4+ Th cells can prevent many autoimmune diseases; however, the factors selecting for these cells remain poorly defined. In transgenic mice with a mutation in the CD4 binding region on class II MHC, the disruption of CD4-class II interactions selected for CD4+ Th cells that expressed surface markers and cytokines associated with regulatory Th cells. Th cells from these mice were enriched for CD45RB(low) as well as CD25+, while they expressed high levels of the transcription factor associated with regulatory T cells, Foxp3, and cytokines, including IL-4, IL-10, and IFN-gamma mRNA and protein. These regulatory Th cells inhibited the function of APCs via IL-10 production, and adoptive transfer of these cells prevented weight loss and inflammation in a model of colitis. CD4+ regulatory Th cells emerged only when interactions between CD4 and class II MHC were deficient on cells of nonhemopoietic origin. These data support a novel model controlling the differentiation of regulatory Th cells and suggest that interactions between CD4 and class II MHC may a useful target for re-educating T cells as a treatment for inflammatory diseases.

Coevolution of markers of innate and adaptive immunity in skin and peripheral blood of patients with erythema migrans

We used multiparameter flow cytometry to characterize leukocyte immunophenotypes and cytokines in skin and peripheral blood of patients with erythema migrans (EM). Dermal leukocytes and cytokines were assessed in fluids aspirated from epidermal suction blisters raised over EM lesions and skin of uninfected controls. Compared with corresponding peripheral blood, EM infiltrates were enriched for T cells, monocytes/macrophages, and dendritic cells (DCs), contained lower proportions of neutrophils, and were virtually devoid of B cells. Enhanced expression of CD14 and HLA-DR by lesional neutrophils and macrophages indicated that these innate effector cells were highly activated. Staining for CD45RO and CD27 revealed that lesional T lymphocytes were predominantly Ag-experienced cells; furthermore, a subset of circulating T cells also appeared to be neosensitized. Lesional DC subsets, CD11c(+) (monocytoid) and CD11c(-) (plasmacytoid), expressed activation/maturation surface markers. Patients with multiple EM lesions had greater symptom scores and higher serum levels of IFN-alpha, TNF-alpha, and IL-2 than patients with solitary EM. IL-6 and IFN-gamma were the predominant cytokines in EM lesions; however, greater levels of both mediators were detected in blister fluids from patients with isolated EM. Circulating monocytes displayed significant increases in surface expression of Toll-like receptor (TLR)1 and TLR2, while CD11c(+) DCs showed increased expression of TLR2 and TLR4; lesional macrophages and CD11c(+) and CD11c(-) DCs exhibited increases in expression of all three TLRs. These results demonstrate that Borrelia burgdorferi triggers innate and adaptive responses during early Lyme disease and emphasize the interdependence of these two arms of the immune response in the efforts of the host to contain spirochetal infection.

Comparison of intracellular cytokine production with extracellular cytokine levels using two flow cytometric techniques

BACKGROUND

We investigated the relation between intracellular cytokine production and extracellular cytokine levels by using two flow cytometric techniques.

METHODS

A two-color flow cytometric technique was used to measure interleukin (IL)-1beta, IL-6, tumor necrosis factor alpha (TNF-alpha), IL-10, and IL-12 production blocked intracellularly with brefeldin A in lipopolysaccharide (LPS)-stimulated CD14(+) monocytes and IL-2, IL-4, and IFN-gamma production in phorbol-12-mirystate-13-acetate (PMA)-stimulated CD3(+) T lymphocytes in samples from patients with rheumatoid arthritis. A flow cytometric microsphere-based immunoassay was performed to detect cytokine secretion in plasma of PMA- and LPS-stimulated whole blood samples.

RESULTS

There was a strong linear correlation between extracellular quantitative (pg/ml) and intracellular semiquantitative detection of LPS-stimulated IL-1beta, IL-6, IL-10, and IL-12 production (r > 0.9). For lymphocytes, extracellularly detected IL-2 and IFN-gamma correlated well with percentages of cytokine-producing cells (r > 0.8). The percentages of IL-4-positive T cells were moderately correlated with the secreted amounts of IL-4 as detected with the microsphere-based immunoassay (r = 0.7).

CONCLUSION

Overall, there was a good correlation between semiquantitative intracellular detection of cytokines and the secreted amounts of cytokines detected with the microsphere based immunoassay.

Relationship between histologic chorioamnionitis and early inflammatory variables in blood, tracheal aspirates, and endotracheal colonization in preterm infants

Histologic results of the placenta are usually not available within the first days of life. We identified inflammatory variables in tracheal aspirates and blood that were associated with histologic chorioamnionitis (HC). A derivation cohort consisted of 62 neonates and a validation cohort of 57 neonates with a gestational age < 31 wk and ventilated on d 1. Tracheal aspirates were taken on d 1 and on d 3, if the patient was still ventilated. HC was diagnosed by light microscopy. Logistic regression was used to identify independent factors in the derivation cohort associated with HC at d 1, 2, and 3. Model performance was studied using receiver operating characteristic curve analysis. Independent factors associated with HC were, at d 1, tracheal aspirate IL-8 >or= 917 pg/mL (odds ratio, 60.7; 95% confidence interval, 11-328); at d 2, blood C-reactive protein >or= 14 mg/L (odds ratio, 9.2; 95% confidence interval, 2-38), blood white blood cell count >or= 10400/mm3 (odds ratio, 7.4; 95% confidence interval, 2-28); and at d 3, blood neutrophil count >or= 4968/mm3 (odds ratio, 14; 95% confidence interval, 3-57). The association with HC was less at d 3 (area under receiver operating characteristic curve, 0.77) when compared with the d 1 model (area under the curve, 0.88; p = 0.09). The models performed equally well in the validation cohort (goodness-of-fit test, p > 0.05). We conclude that the d 1 and d 2 models can be used as diagnostic factors for HC. Tracheal aspirate IL-8 taken immediately after birth was equally accurate in the diagnosis of HC as systemic inflammatory response at d 2 and better than on d 3.

Carbamazepine-induced hypersensitivity syndrome associated with transient hypogammaglobulinaemia and reactivation of human herpesvirus 6 infection demonstrated by real-time quantitative polymerase chain reaction

Drug-induced hypersensitivity syndrome (HS) is a rare but severe disease with multiorgan failure. Many different precipitating factors have been reported, but the pathophysiology of HS remains unknown. However, the association of the human herpesvirus (HHV) family, particularly of HHV-6, has recently been reported in patients with HS. We report a 14-year-old boy who was diagnosed as having carbamazepine-induced HS based on the clinical course, laboratory data and results of drug-induced lymphocyte stimulation tests. In addition, the reactivation of HHV-6 was demonstrated by real-time quantitative polymerase chain reaction and by significantly increased levels of the specific antibody in his paired sera. Furthermore, transient hypogammaglobulinaemia was detected in the early stage of the disease. In addition, serum levels of interferon-gamma, interleukin (IL)-6, IL-5 and eosinophil cationic protein, which were increased on admission, decreased dramatically after steroid therapy. This is the first report of carbamazepine-induced HS associated with reactivation of HHV-6, transient hypogammaglobulinaemia, increased serum levels of inflammatory cytokines and activated eosinophils. This case might contribute to the understanding of the pathophysiology of HS.

Beta 2-microglobulin as a negative regulator of the immune system: high concentrations of the protein inhibit in vitro generation of functional dendritic cells

Two common features in human immunodeficiency virus infection and acquired immunodeficiency syndrome, rheumatoid arthritis, and hematologic malignancies including multiple myeloma are elevated serum levels of beta(2)-microglobulin (beta(2)M) and activation or inhibition of the immune system. We hypothesized that beta(2)M at high concentrations may have a negative impact on the immune system. In this study, we examined the effects of beta(2)M on monocyte-derived dendritic cells (MoDCs). The addition of beta(2)M (more than 10 microg/mL) to the cultures reduced cell yield, inhibited the up-regulation of surface expression of human histocompatibility leukocyte antigen (HLA)-ABC, CD1a, and CD80, diminished their ability to activate T cells, and compromised generation of the type-1 T-cell response induced in allogeneic mixed-lymphocyte reaction. Compared with control MoDCs, beta(2)M-treated cells produced more interleukin-6 (IL-6), IL-8, and IL-10. beta(2)M-treated cells expressed significantly fewer surface CD83, HLA-ABC, costimulatory molecules, and adhesion molecules and were less potent at stimulating allospecific T cells after an additional 48-hour culture in the presence of tumor necrosis factor-alpha and IL-1beta. During cell culture, beta(2)M down-regulated the expression of phosphorylated mitogen-activated protein (MAP) kinases, extracellular signal-related kinase (ERK), and mitogen-induced extracellular kinase (MEK), inhibited nuclear factor-kappaB (NF-kappaB), and activated signal transducer and activator of transcription-3 (STAT3) in treated cells, all of which are involved in cell differentiation and proliferation. Thus, our study demonstrates that beta(2)M at high concentrations retards the generation of MoDCs, which may involve down-regulation of major histocompatibility complex class I molecules, inactivation of Raf/MEK/ERK cascade and NF-kappaB, and activation of STAT3, and it merits further study to elucidate the underlying mechanisms.

Modulation of IL-8 and RANTES release in human conjunctival epithelial cells: primary cells and cell line compared and contrasted

PURPOSE

Recent research indicates that epithelial cells of the ocular surface can contribute to the allergic reaction by the release of inflammatory and/or chemotactic mediators. In this study, the role of two inflammatory mediators, previously identified in the tear film of ocular allergy subjects, TNF-alpha and IFN-gamma, were evaluated for their effect on the release of two chemotactic mediators, IL-8 and RANTES, from cultured human conjunctival epithelial cells.

METHODS

Human conjunctival epithelial cells (primary cells or HC0597 cell line) were grown to confluence and stimulated with various concentrations of TNF-alpha, IFN-gamma, or a combination of both. Supernatants were collected at 6, 24, and 48 hours and stored frozen for subsequent ELISA analyses of RANTES and IL-8.

RESULTS

RANTES and IL-8 release from HC0597 cells was stimulated in a dose- and time-dependent manner following treatment with TNF-alpha. However, only RANTES release was modulated by IFN-gamma treatment. Treatment of HC0597 cells with both TNF-alpha and IFN-gamma resulted in a synergistic increase in the release of RANTES. This synergistic effect was confirmed using primary cultures of human conjunctival epithelial cells.

CONCLUSIONS

Stimulation of conjunctival epithelium with proinflammatory mediators, TNF-alpha and/or IFN-gamma, generated the release of the chemotactic factors IL-8 and RANTES, which could act to prolong inflammation. These two chemokines may prolong inflammation by recruiting eosinophils to the ocular surface. This is the first study to compare chemokine release in a cell line and primary cells; similar chemokine release after mediator stimulation was demonstrated, indicating that the two cell types are phenotypically similar.

Simultaneous detection of 15 human cytokines in a single sample of stimulated peripheral blood mononuclear cells

Cytokines secreted by cells of the immune system can alter the behavior and properties of immune or other cells. At a site of inflammation, sets of cytokines interact with immune cells, and their combined effect is often more important than the function of one isolated component. Conventional techniques, such as enzyme-linked immunosorbent assays, generally require large quantities of cells to characterize a complete cytokine profile of activated lymphocytes. The Bio-Plex system from Bio-Rad Laboratories combines the principle of a sandwich immunoassay with the Luminex fluorescent-bead-based technology. We developed a multiplex cytokine assay to detect different cytokines simultaneously in culture supernatant of human peripheral blood mononuclear cells stimulated with antigen and with mitogen. Fifteen human cytokines (interleukin 1alpha [IL-1alpha], IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-15, IL-17, IL-18, gamma interferon, and tumor necrosis factor alpha) were validated with a panel of healthy individuals, rheumatoid arthritis patients, and juvenile idiopathic arthritis patients. Comparing the multiplex assay with a regular enzyme-linked immunosorbent assay technique with this donor panel resulted in correlation coefficients for all cytokines ranging from 0.75 to 0.99. Intra-assay variance proved to be less then 10%, whereas interassay variability ranged between 10 and 22%. This multiplex system proved to be a powerful tool in the quantitation of cytokines. It will provide a more complete picture in differences between activated lymphocyte cytokine profiles from healthy individuals and those from patients with chronic inflammatory diseases.

Multiplexed microsphere-based flow cytometric assays

Flow cytometry has become an indispensable tool for clinical diagnostics and basic research. Although primarily designed for cellular analysis, flow cytometers can detect any particles in the lower micron range, including inert microspheres of different sizes, dyed with various fluorochromes. Over the past 20 years, microspheres have been used as calibrators for flow cytometers and also as a solid support for numerous molecular reactions quantitated by flow cytometry. Proteins, oligonucleotides, polysaccharides, lipids, or small peptides have been adsorbed or chemically coupled to the surface of microspheres to capture analytes that are subsequently measured by a fluorochrome-conjugated detection molecule. More recently, assays for similar analytes have been multiplexed, or analyzed in the same assay volume, by performing each reaction on a set of microspheres that are dyed to different fluorescent intensities and, therefore, are spectrally distinct. Some recent applications with fluorescent microspheres have included cytokine quantitation, single nucleotide polymorphism genotyping, phosphorylated protein detection, and characterization of the molecular interactions of nuclear receptors. The speed, sensitivity, and accuracy of flow cytometric detection of multiple binding events measured in the same small volume have the potential to replace many clinical diagnostic and research methods and deliver data on hundreds of analytes simultaneously.

Spectrum of ocular allergy

PURPOSE OF REVIEW

To elaborate and review the immunologic spectrum of the five basic types of ocular allergy.

RECENT FINDINGS

Perennial allergic conjunctivitis (PAC) appears to be an extension of seasonal allergic conjunctivitis (SAC) based on the similarity of clinical symptoms and the immune mechanism involved. T helper type 2 (TH2)-type cytokines, increased ratio of TH1/TH2 cytokines and increased statement of adhesion molecules all appear to play an integral role in the inflammatory process of SAC and PAC. Vernal keratoconjunctivitis (VKC), which is a pediatric disease, differs from SAC and PAC by its more severe and chronic nature. Increased numbers of T cells, eosinophils (along with the products of degranulation), chemokines and their receptors may contribute to the more serious symptoms of VKC. Atopic keratoconjunctivitis (AKC) is similar to VKC by the increased concentration of cytokines involved (i.e. interleukin-4 and -5). Despite clinical similarities with VKC, the presence of atopic dermatitis, along with some differences in clinical signs, make AKC a separate entity, which is sometimes referred to as an adult variant of VKC. Giant papillary conjunctivitis has similar cell involvement as VKC and AKC. However, giant papillary conjunctivitis differs from VKC and AKC by the clinical signs present (i.e. the presence of giant papillae) and the necessary concurrent contact lens wear.

SUMMARY

The important differences and similarities observed in these five types of allergic diseases might help to better treat the patients affected with these disorders.

Pathophysiology of ocular allergy: the roles of conjunctival mast cells and epithelial cells

Allergic eye disease is associated with IgE-mediated conjunctival inflammation leading to signs of immediate hypersensitivity, including redness, itching, and tearing. Pathologic studies using conjunctival mast cells demonstrate that these cells, when sensitized with IgE antibody and exposed to environmental allergens, release mediators involved with allergic inflammation. The type, release kinetics, and concentration of these mediators in the conjunctiva have not been completely characterized. The ability to isolate and purify mast cells and epithelial cells from human conjunctival tissue has permitted the study of mediator release and cell-to-cell signaling in this tissue. Our laboratory has developed in vitro and in vivo models to better understand how inflammatory cells are recruited to and infiltrate conjunctival tissues. These models demonstrate that mast-cell activation may supply sufficient cytokine signaling to initiate and direct the well-orchestrated trafficking of eosinophils to the ocular surface, facilitate their adhesion, and cause release of potent mediators of ocular inflammation.

BD Biosciences contributions in CD4 counting and immune status for HIV/AIDS

BD Biosciences is a leader in the use of flow cytometry for determining immune system status and for counting CD4 cells in patients with human immunodeficiency virus (HIV) infection. The company has gained this position through many years of basic research and product development in immunology and cell biology, dye chemistry, immunoassays, instrumentation, and software. Some of the highlights of these developments and their historical perspective are described in this review.

CD1d-restricted human natural killer T cells are highly susceptible to human immunodeficiency virus 1 infection

Human natural killer (NK) T cells are unique T lymphocytes that express an invariant T cell receptor (TCR) Valpha24-Vbeta11 and have been implicated to play a role in various diseases. A subset of NKT cells express CD4 and hence are potential targets for human immunodeficiency virus (HIV)-1 infection. We demonstrate that both resting and activated human Valpha24(+) T cells express high levels of the HIV-1 coreceptors CCR5 and Bonzo (CXCR6), but low levels of CCR7, as compared with conventional T cells. Remarkably NKT cells activated with alpha-galactosylceramide (alpha-GalCer)-pulsed dendritic cells were profoundly more susceptible to infection with R5-tropic, but not X4-tropic, strains of HIV-1, compared with conventional CD4(+) T cells. Furthermore, resting CD4(+) NKT cells were also more susceptible to infection. After initial infection, HIV-1 rapidly replicated and depleted the CD4(+) subset of NKT cells. In addition, peripheral blood NKT cells were markedly and selectively depleted in HIV-1 infected individuals. Although the mechanisms of this decline are not clear, low numbers or absence of NKT cells may affect the course of HIV-1 infection. Taken together, our findings indicate that CD4(+) NKT cells are directly targeted by HIV-1 and may have a potential role during viral transmission and spread in vivo.