A simple nested RT-PCR method for quantitation of the relative amounts of multiple cytokine mRNAs in small tissue samples

The role of T-cell leukemia translocation-associated gene protein in human tumorigenesis and osteoclastogenesis

Synovial tissues of patients with rheumatoid arthritis (RA) include factors regulating bone resorption, such as receptor activator NF-κB ligand (RANKL), TNF-α, IL-6, IL-17, and IFN-γ. However, in addition to these cytokines, other factors expressed in synovial tissues may play a role in regulating bone resorption. In 2009, we demonstrated that novel peptides from T-cell leukemia translocation-associated gene (TCTA) protein expressed in synovial tissues from patients with RA inhibit human osteoclastogenesis, preventing cellular fusion via the interaction between TCTA protein and a putative counterpart molecule. Only a few studies on the role of TCTA protein have been reported. Genomic Southern blots demonstrated a reduced TCTA signal in three of four small cell lung cancer cell lines, suggesting the loss of one of the two copies of the gene. In the current paper, we reviewed the roles of TCTA protein in lung cancer cell lines and human osteoclastogenesis.

[Chlamydia-associated arthritis and enteropathic arthritis--two important spondyloarthritides]

Spondyloarthritis (SpA) includes reactive arthritis (ReA) and enteropathic arthritis (EA), which are clinically important but often misdiagnosed. ReA, sterile inflammatory arthritis, arises after certain genitourinary or gastrointestinal infections. Chlamydia are the most common pathogens causing ReA; ReA due to Chlamydia infection is called Chlamydia-associated arthritis (Chl-AA). Recently, Chlamydia trachomatis was detected in the synovial tissue from patients with ReA by electronmicroscopy. In addition, mRNA as well as DNA has been detected in the synovial tissue, suggesting that Chlamydia are viable in inflamed joints. Thus, the notion that ReA is a sterile inflammation should be reconsidered. Chl-AA patients, especially women, often show no symptoms and signs of genitourinary infection. Thus, Chl-AA should be suspected in patients with inflammatory arthritides that is difficult to diagnose. EA is accompanied by inflammatory bowel diseases (IBD). In Japan, over 130,000 individuals have IBD; IBD is diagnosed in 6,500 individuals every year. Around 10% IBD patients develop arthritis, suggesting that 13,000 patients develop arthritis every year. SpA includes peripheral and axial arthritis; axial arthritis includes spondylitis and sacroiliac arthritis. Sacroiliac joint tests need to be performed to diagnose sacroiliac arthritis. Rheumatologists should be aware of the pathogenesis of Chl-AA and EA and diagnose and treat these diseases appropriately.

Effects of NSAIDs on Differentiation and Function of Human and Murine Osteoclasts - Crucial 'Human Osteoclastology'

Osteoclasts play a critical role in both normal bone metabolism and bone resorption in the joints of patients with rheumatoid arthritis. It has been reported that non-steroidal anti-inflammatory drugs (NSAIDs) inhibit murine osteoclastogenesis in vitro and murine arthritis models in vivo, but not the destruction of joints of patients with rheumatoid arthritis. In the current review article, we review the recent findings in the effect of NSAIDs on the formation and function of human and murine osteoclasts both in vitro and in vivo, underlining the importance of studies using human osteoclasts. Since 2009, we have suggested a novel term ‘human osteoclastology’.

Cytokine mRNA expression is decreased in the subplantar muscle of rat paw subjected to carrageenan-induced inflammation after low-level laser therapy

OBJECTIVE

The objective of this work was to investigate the anti-inflammatory effects of low-level laser therapy, applied at different wavelengths (660 and 684 nm), on cytokine mRNA expression after carrageenan-induced acute inflammation in rat paw.

BACKGROUND DATA

Low-level laser therapy (LLLT) has been observed to reduce pain in inflammatory disorders. However, little is known about the mechanisms behind this effect or whether it is wavelength-specific.

MATERIALS AND METHODS

The test sample consisted of 32 rats divided into four groups: A(1) (control-saline), A(2) (carrageenan-only), A(3) (carrageenan + 660 nm laser therapy), and A(4) (carrageenan + 684 nm laser therapy). The animals from groups A(3) and A(4) were irradiated 1 h after induction of inflammation by carrageenan injection. Continuous-wave red lasers with wavelengths of 660 and 684 nm and dose of 7.5 J/cm(2) were used.

RESULTS

Both the 660 nm and 684 nm laser groups had 30%-40% lower mRNA expression for cytokines TNF-alpha, IL-1beta, and IL-6 in the paw muscle tissue than the carrageenan-only control group. Cytokine measurements were made 3 h after laser irradiation of the paw muscle, and all cytokine differences between the carrageenan-only control group and the LLLT groups were statistically significant (p < 0.001).

CONCLUSIONS

LLLT at the 660-nm and 684-nm wavelengths administered to inflamed rat paw tissue at a dose of 7.5 J/cm(2) reduce cytokine mRNA expression levels within 3 h in the laser-irradiated tissue.

IFN-gamma-producing human T cells directly induce osteoclastogenesis from human monocytes via the expression of RANKL

The current study explored our hypothesis that IFN-gamma-producing human T cells inhibit human osteoclast formation. Activated T cells derived from human PBMC were divided into IFN-gamma-producing T cells (IFN-gamma(+) T cells) and IFN-gamma-non-producing T cells (IFN-gamma(-) T cells). IFN-gamma(+) T cells were cultured with human monocytes in the presence of macrophage-CSF alone. The concentration of soluble receptor activator of NF-kappaB ligand (RANKL) and IFN-gamma, and the amount of membrane type RANKL expressed on T cells, were measured by ELISA. In the patients with early rheumatoid arthritis (RA) treated with non-steroidal anti-inflammatory drugs alone, CD4+ T cells expressing both IFN-gamma and RANKL were detected by flow cytometry. Surprisingly, IFN-gamma(+) T cells, but not IFN-gamma(-) T cells, induced osteoclastogenesis from monocytes, which was completely inhibited by adding osteoprotegerin and increased by adding anti-IFN-gamma antibodies. The levels of both soluble and membrane type RANKL were elevated in IFN-gamma(+) T cells. The ratio of CD4+ T cells expressing both IFN-gamma and RANKL in total CD4+ T cells from PBMC was elevated in RA patients. Contrary to our hypothesis, IFN-gamma(+) human T cells induced osteoclastogenesis through the expression of RANKL, suggesting that Th1 cells play a direct role in bone resorption in Th1 dominant diseases such as RA.

Induction of Interleukin-6 and Interleukin-8 Gene Expression by Root Canal Sealers in Human Osteoblastic Cells

Histological investigations have demonstrated that root canal sealers can induce mild to severe inflammatory alternations. However, there is little information on the precise mechanisms about root canal sealers-induced inflammatory reaction. Dysregulated cytokine productions at local disease sites have been considered to be major contributors to the development of inflammatory diseases. Interleukin (IL)-6 and IL-8 released have been reported to play an important role in the pathogenesis of inflammation. The aim of this study was to investigate the effects of root canal sealers N2 (zinc-oxide eugenol based) and AH Plus (epoxy resin based) on the expression of IL-6 and IL-8 mRNA gene in human osteoblastic cell line U2OS cells. The levels of mRNAs were measured by the semi-quantitative reverse-transcriptase polymerase chain reaction analysis. The exposure of quiescent U2OS cells to N2 and AH Plus resulted in the induction of IL-6 and IL-8 mRNA gene expression (p < 0.05). The intensity of IL-8 mRNA gene was found to be significant higher than IL-6 mRNA gene (p < 0.05). Taken together, the activation of IL-6 and IL-8 mRNA gene expression may be one of the pathogenesis of zinc oxide-eugenol based and epoxy resin based root canal sealers-induced periapical inflammation.

Mutations in the desat1 gene reduces the production of courtship stimulatory pheromones through a marked effect on fatty acids in Drosophila melanogaster

In Drosophila melanogaster, desat1 is involved in the synthesis of fatty acids (FAs), some of which are precursors in the production of unsaturated hydrocarbons (HCs) in position 7 (7-HC) that play an important role in mating behaviour. Three GS lines with P-element insertion in the desat1 promoter showed more or less decrease in 7-HC, depending on the site of insertion. The forced transcription of genomic 5'P-flanking sequence led to opposite effects upon 7-HC, depending on the orientation of the insertions. Homozygous GS12251 flies showed particularly low 7-HC levels and severely affected courtship parameters (courtship latency doubled, number of copulation attempts decreased by half). After transposon excision, the HC phenotype was reversed in most lines, showing that the location of the transposon was responsible for the mutant phenotype. In homozygous GS12251 flies, the amounts of FAs and desat1 transcripts were reduced by half, compared to the amounts in heterozygous or wild-type flies. Relative proportions among FAs were quite similar to those of wild-type, with the exception of a slight decrease in myristoleic, palmitoleic and vaccenic acid. As the reduction of desat1 activity in the mutant resulted in a large decrease in both unsaturated and saturated FAs, it could impair FA and lipid metabolism, as it is known in vertebrates.

Enriching for HIV-infected cells using anti-gp41 antibodies indirectly conjugated to magnetic microbeads

The isolation of a pure population of human immunodeficiency virus (HIV)-infected cells is highly desirable for evaluating the impact of HIV on cellular gene expression. Given that HIV gp41 transmembrane protein is anchored on the surface of HIV-infected cells, we evaluated the use of pooled anti-gp41 monoclonal antibodies (MAbs) and HIV immunoglobulins (HIV-Igs) indirectly conjugated to magnetic microbeads to positively select for infected cells. We demonstrate that pooled anti-gp41 monoclonal antibodies enriched for H9 cells infected with HIV IIIB by approximately 98%. Peripheral blood mononuclear cells (PBMCs) infected with a primary (HIV strain 302151) or laboratory-adapted (IIIB) strain were enriched by 54%-62%, depending on the initial viral inoculum. Using HIV-Ig in this magnetic positive-selection approach was also highly efficient for enriching for H9 cells infected with IIIB but less efficient for infected PBMCs. Both types of antibodies used in the selection process resulted in > 80 viability of selected HIV-infected cells. Analysis of interleukin 2 (IL-2) mRNA expression using real-time reverse transcription PCR (RT-PCR) of the HIV-enriched population demonstrated a higher level of IL-2 mRNA, by approximately four cycles, and an 8-fold increase in IL-2 expression, as evaluated by intracellular staining and flow cytometric analysis, in comparison to gp41-negative cells. Collectively, these data illustrate that antibodies targeting gp41 can be used to enrich for HIV-positive populations. This represents a novel approach for studying the impact of HIV on infected cells and on bystander/uninfected cells.

High expression of p40(tax) and pro-inflammatory cytokines and chemokines in the lungs of human T-lymphotropic virus type 1-related bronchopulmonary disorders

STUDY OBJECTIVE

Human T-lymphotropic virus type 1 (HTLV-1) is closely associated with the development of certain pulmonary diseases, such as bronchiolitis, although the pathologic mechanism remains unclear. To elucidate the pathogenesis of HTLV-1-associated bronchopulmonary disorders, we analyzed the relationship between expression of p40(tax), a regulatory component of HTLV-1 that stimulates various host genes, and synthesis of pro-inflammatory cytokines and chemokines by cells in BAL fluid (BALF) obtained from HTLV-1-infected patients.

DESIGN

Reverse transcription-polymerase chain reaction was used to compare the expression of p40(tax) and pro-inflammatory cytokines and chemokines messenger RNA (mRNA) in BALF of 10 HTLV-1 carriers and 7 healthy subjects. We also studied the correlation between these parameters and the proportion of lymphocytes in BALF.

RESULTS

The expression levels of pro-inflammatory cytokines (interferon [IFN]-gamma, interleukin-2) and chemokines (monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1alpha, IFN-gamma-inducible protein-10 [IP-10]) were significantly higher in BALF of patients than of healthy subjects. The expression of IFN-gamma and MIP-1alpha mRNA correlated with that of p40(tax). IFN-gamma and IP-10 mRNA expression correlated with the proportion of lymphocytes in BALF. The percentage of lymphocytes in BALF increased with higher expression levels of p40(tax) mRNA, although the correlation was not significant.

CONCLUSION

Our results suggested that p40(tax) seems be involved in the development of HTLV-1-associated bronchopulmonary disorders at least in part through the local production of pro-inflammatory cytokines and chemokines.

Standard-curve competitive RT-PCR quantification of myogenic regulatory factors in chicken embryos

The reverse transcription-polymerase chain reaction (RT-PCR) is the most sensitive method used to evaluate gene expression. Although many advances have been made since quantitative RT-PCR was first described, few reports deal with the mathematical bases of this technique. The aim of the present study was to develop and standardize a competitive PCR method using standard-curves to quantify transcripts of the myogenic regulatory factors MyoD, Myf-5, Myogenin and MRF4 in chicken embryos. Competitor cDNA molecules were constructed for each gene under study using deletion primers, which were designed to maintain the anchorage sites for the primers used to amplify target cDNAs. Standard-curves were prepared by co-amplification of different amounts of target cDNA with a constant amount of competitor. The content of specific mRNAs in embryo cDNAs was determined after PCR with a known amount of competitor and comparison to standard-curves. Transcripts of the housekeeping -actin gene were measured to normalize the results. As predicted by the model, most of the standard-curves showed a slope close to 1, while intercepts varied depending on the relative efficiency of competitor amplification. The sensitivity of the RT-PCR method permitted the detection of as few as 60 MyoD/Myf-5 molecules per reaction but approximately 600 molecules of MRF4/Myogenin mRNAS were necessary to produce a measurable signal. A coefficient of variation of 6 to 19% was estimated for the different genes analyzed (6 to 9 repetitions). The competitive RT-PCR assay described here is sensitive, precise and allows quantification of up to 9 transcripts from a single cDNA sample.

Induction of interleukin-6 gene expression by pro-inflammatory cytokines and black-pigmented Bacteroides in human pulp cell cultures

AIM

To investigate the effect of pro-inflammatory cytokines and black-pigmented Bacteroides on the expression of IL-6 gene in human pulp fibroblasts.

METHODOLOGY

IL-1alpha, tumour necrosis factor-alpha (TNF-alpha) and the supernatants of Porphyromonas endodontalis, P. gingivalis and Prevotella intermedia were used to evaluate IL-6 gene expression in human pulp fibroblasts. The levels of mRNAs were measured by the quantitative reverse-transcriptase polymerase chain reaction analysis.

RESULTS

Investigations of the time dependence of IL-6 mRNA expression in pro-inflammatory cytokines-treated cells revealed a rapid accumulation of the transcript after 2 h of exposure and remained elevated throughout the 24-h incubation period. In addition, black-pigmented Bacteroides also induced IL-6 gene expression in human pulp fibroblasts.

CONCLUSIONS

Pro-inflammatory cytokines and black-pigmented Bacteroides may be involved in developing pulpal inflammation through the stimulation of IL-6 production.

Immune features of seronegative and seropositive arthritis in early synovitis studies

Synovitis of recent onset is a challenging problem, both from a diagnostic and a mechanistic point of view. The role of the immune system in mediating the systemic and synovial inflammatory response remains an area of active investigation. Studies in early synovitis cohorts have confirmed the relatively specific association of rheumatoid factor positive polyarthritis with a number of autoantibodies, particularly anticyclical citrullinated peptide (CCP) antibodies, antifilaggarin antibodies (AFA), and anti-Sa antibodies. Immunopathologic studies of synovial tissue samples from patients with early synovitis have generally suggested quantitative rather than qualitative differences between various forms of synovitis. In particular, Th1 cytokines appear to predominate in rheumatoid arthritis and psoriatic synovitis, while Th2 cytokines are more often detectable in the synovium of reactive arthritis patients. This latter observation is consistent with an immune response profile that favors persistence of intracellular organisms.

Differential expression of inhibitory and activating CD94/NKG2 receptors on NK cell clones

Natural killer cells are known to express a variety of surface receptors involved in HLA class I monitoring. It is thus of interest to investigate the clonal distribution and relative expression levels of activating versus inhibitory NK receptors. We have developed a quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay designed to determine specific and absolute mRNA levels for NKG2-A/B, -C, -E, -F, -H and NKG2-D. When analyzing NK cell clones derived from a single donor we found differential expression of inhibitory (NKG2-A/B) versus triggering (NKG2-C and potentially -E, -F, -H) NK receptor chains. The generation of the splice variants NKG2-E and -H seemed to occur at a constant ratio. We further compared NKG2 transcript levels to surface receptor expression as monitored by flow cytometric analysis and to NK cell cytotoxicity as detected by reverse ADCC: a clear correlation was observed. Thus, the data obtained reveal a substantial variability in the NKG2 repertoire among NK cell subpopulations, which is likely to affect the sensitivity and reactivity towards the ligand HLA-E.

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases define the migratory characteristics of human monocyte-derived dendritic cells

Dendritic cells (DCs) have an essential role in the initiation of immune responses as they deliver antigen/epitope and the appropriate signals to activate naïve T cells and thus start an immune response. In order to fulfil their function, DCs have to patrol different part of the body, thus migrating through the extracellular matrix to sample the local 'antigenic' environment. In the present study, we have investigated which enzymes might be involved in this process using the Matrigel trans-well migration assay, an in vitro model of extracellular matrix migration. In this assay we analysed the migratory ability of interleukin-4 (IL-4)/granulocyte macrophage-colony-stimulating factor (GM-CSF)-derived immature DCs as well as mature DCs, induced by tumour necrosis factor-alpha (TNF-alpha) and modified vaccinia virus Ankara (MVA). The 'mature' DCs showed an increased migration through Matrigel, which was significantly inhibited by inhibitors of matrix metalloproteinases (MMP). We also observed that the dominant MMP involved in this process was MMP-9, and a concomitant decrease of the endogenous tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 was also observed. Collectively these data suggest that the balance between MMP/TIMP determines the net migratory capacity of human DCs. Surprisingly, TIMP-3 was significantly increased in mature DC. Our data thus indicate that MMP and TIMP play a role in the migratory ability of human DCs. Our results also suggest that TIMP-3 expression might represent a new marker of maturation of human DCs.

Semi-quantitative analysis of cytokine mRNA expression induced by the herbal medicine Sho-saiko-to (TJ-9) using a Gel Doc system

The RT-PCR method was employed to determine the cytokine mRNA expression of human peripheral lymphocytes induced by the Japanese herbal medicine Sho-saiko-to (TJ-9). The results showed that the mRNA expression of IL-12, IL-1beta, IL-10, TNF-alpha, G-CSF, and IFN-gamma increased after 6 hr in culture. This is the first reported finding that TJ-9 is an IFN-gamma inducer. Next, cytokine mRNA expression was semi-quantitatively measured using the Gel Doc system with a CCD camera and then statistically analyzed in order to determine which component of TJ-9 was the true cytokine inducer. The results showed that the scutellaria root is the main component inducing the cytokines, while the glycyrrhiza root is the secondary component. When the cytokine concentrations in the supernatants of cell cultures were measured by ELISA, the levels of IL-12, IL-1beta, IL-10, TNF-alpha, and G-CSF reflected mRNA expression levels in the cell fraction. However, the level of IFN-gamma was below the detectable limit. The effects of various reagents on many different kinds of cytokine mRNA expression could be analyzed objectively in a short time using the Gel Doc system. Many important findings could be demonstrated by this simple, easy, sensitive, and cheap method. After the clinical significance of cytokine analysis is confirmed, this method may become a useful clinical examination tool.

Measurement of cytokine secretion, intracellular protein expression, and mRNA in resting and stimulated peripheral blood mononuclear cells

Quantitation of cytokine production is a valuable adjunct to standard immunologic assays in defining several pathologic processes. Nevertheless, there is little agreement about which tissues should be assayed, which type of assay should be performed, and which stimulation protocol should be used. As these types of assays enter the clinical arena, there is need for standardization. There is also a need to maximize the amount of information which may be derived from a single sample. We compared secreted interleukin 4 (IL-4), IL-2, IL-6, tumor necrosis factor alpha (TNF-alpha), and gamma interferon proteins as measured by enzyme-linked immunosorbent assay with intracellular cytokine production (IL-2 and gamma interferon) as detected by flow cytometry and quantitative competitive PCR for IL-2, IL-4, TNF-alpha, and gamma interferon mRNA and cDNA. Results from unstimulated cells and cells stimulated with phorbol myristate acetate, phytohemagglutinin, and phorbol myristate acetate plus phytohemagglutin were compared. All three methodologies detected significant stimulation of cytokine production. The combination of phytohemagglutinin and phorbol myristate acetate was overall the most-potent stimulus.

Lipopolysaccharide stimulates the proliferation of human CD56+CD3- NK cells: a regulatory role of monocytes and IL-10

NK cells recognize and kill tumor cells and normal cells, and these play an important role in immune defense in cancer, infectious disease, and autoimmunity. NK killing is regulated by positive or negative signals derived from the interaction of surface receptors with ligands on the target cells. However, the mechanisms controlling the proliferation and maintenance of NK cells in normal human individuals are less clearly defined. In this study, using an entirely autologous system, we demonstrate that human peripheral blood CD3-CD56+, killer cell-inhibitory receptor (KIR)-expressing cells proliferate and expand in response to LPS. These responses are enhanced in the presence of anti-IL-10 receptor-blocking Abs or on the removal of CD14+ cells from the cultures. This enhancement is also reflected in substantial increases in cytolytic activity and IFN-gamma production. The negative effect of CD14+ cells may also be IL-10 mediated, IL-10 being lost from the culture supernatants of CD14-depleted PBMC and rIL-10 reversing the effect of this depletion. On the other hand, mRNA for the p35 and p40 subunits of IL-12 is still induced in CD14-depleted cultures. The expansion of CD3-CD56+ cells was also inhibited by CTLA4-Ig, indicating a role for CD80/86. B lymphocytes were not required for the expansion of CD3-CD56+ cells, whereas removal of MHC class II+ cells from CD14-depleted cultures resulted in a complete abrogation of these responses. Expansion of CD3-CD56+ cells was reconstituted in MHC class II-depleted cell cultures by adding back monocyte-derived dendritic cells. These results indicate that the responses of CD3-CD56+ NK cells to LPS may be driven by a MHC class II+ B7+ CD14- peripheral population, most likely blood dendritic cells.

Expression of cytokine genes during pneumococcal and nontypeable Haemophilus influenzae acute otitis media in the rat

Acute otitis media (AOM) elicits potent inflammatory responses from the cells of the middle ear mucosa as well as from infiltrating leukocytes. To explore host responses during experimental AOM induced by Streptococcus pneumoniae type 3 and nontypeable Haemophilus influenzae (NTHi), otomicroscopy findings and expression of cytokine genes in the middle ear were monitored up to 1 month postinoculation. The mucosa and infiltrating cells responded rapidly to the bacterial challenge. Otomicroscopically, AOM appeared 1 day after NTHi inoculation and 3 days after pneumococcus inoculation. Pneumococcal AOM was more severe than NTHi otitis, but in general, lower transcript levels were detected in pneumococcus-infected than in NTHi-infected animals. Interleukin-6 (IL-6) mRNA levels peaked at 3 to 6 h for both pneumococcus-infected and NTHi-infected animals. IL-1alpha, tumor necrosis factor alpha, and IL-10 mRNA levels peaked at 6 h for NTHi otitis and 1 to 3 days for pneumococcal otitis. Comparing otomicroscopy with expression profiles, it would appear that the majority of cytokine mRNAs had passed their peak before the AOM diagnosis could be made clinically. Only transforming growth factor beta mRNA followed a slower time course, peaking very late and continuing expression even after the AOM was otomicroscopically resolved. IL-2 and IL-4 mRNAs were not detected in any animal at any time. Most of the investigated cytokines are very early markers for AOM and may be involved in initiation of inflammation, but they would be poor targets for pharmacological manipulation since their levels decline before clinical signs appear.

Sibling species in the Llutzomyia longipalpis complex differ in levels of mRNA expression for the salivary peptide, maxadilan

Maxadilan is a small ( approximately 7 kDa) protein found in the saliva of sand fly species in the Lutzomyia longipalpis complex, vectors of the parasite causing visceral leishmaniasis, Leishmania chagasi. It is a potent vasodilator and also has immunomodulatory affects. Maxadilan recovered from different sibling species of the Lu. longipalpis complex differ in amino acid content by as much as 23%, however all variants possess equivalent vasodilatory activity. Therefore, the dramatic differences in vasodilatory activity of the saliva from different sibling species is probably due to differences in the amounts of maxadilan in their saliva. This is significant because it has been suggested that maxadilan may influence the pathogenesis of leishmanial infections. In this study we measured the amount of maxadilan messenger RNA (mRNA) per pair of salivary glands from individual sand flies by quantitative reverse transcription polymerase chain reaction (RT-PCR) using a competitive method. We report a method using the gene of interest, in this case maxadilan, amplified by the PCR from genomic DNA, as a competitor in the quantitative RT-PCR, taking advantage of differences in the size of these products due to the presence of an intron. Significant differences in amounts of maxadilan mRNA among colonies from Central and South America are described. We found a strong correlation between the amount of maxadilan mRNA detected in salivary glands of different Lu. longipalpis sibling species and previously described differences in the size of erythemas produced by the bite of these species. Therefore, variation in the amount of mRNA suggests that differences in the vasodilatory properties of saliva among the different sibling species are the result of differences in the amount of maxadilan present in the saliva and not differences in the potency of maxadilan peptide variants. The geographical distribution of species with high or low levels of maxadilan gene expression are concordant with the distribution of atypical cutaneous leishmaniasis resulting from infection with Le. chagasi, lending credence to earlier suggestions that maxadilan may be involved with visceralization of this parasite.

Production of basic fibroblast growth factor and interleukin 6 by human smooth muscle cells following infection with Chlamydia pneumoniae

Chlamydia pneumoniae infection has been associated with asthma and atherosclerosis. Smooth muscle cells represent host cells for chlamydiae during chronic infection. In this study we demonstrated that C. pneumoniae infection of human smooth muscle cells in vitro increased production of interleukin 6 (IL-6) and basic fibroblast growth factor (bFGF) as shown by reverse transcription-PCR, immunoblotting, and enzyme-linked immunosorbent assay. In contrast, levels of platelet-derived growth factor A-chain mRNA were not affected after infection. The stimulation of bFGF and IL-6 production was most effective when viable chlamydiae were used as inoculum. Furthermore, inhibition of bacterial protein synthesis with chloramphenicol prevented up-regulation of IL-6 and bFGF in infected cells. Addition of IL-6 antibody to infected cultures diminished bFGF expression, indicating involvement of produced IL-6. These findings suggest that chlamydial infection of smooth muscle cells elicits a cytokine response that may contribute to structural remodeling of the airway wall in chronic asthma and to fibrous plaque formation in atherosclerosis.

A fluorimeter-based RT-PCR method for the detection and quantitation of porcine cytokines

In this paper, we describe a fluorimeter-based, closed-tube, polymerase chain reaction (PCR) assay for the detection and quantification of the mRNA of porcine interleukin 1alpha (IL1alpha) and interleukin 2 (IL2) cytokines in peripheral blood leukocytes (PBLs) using melting curve analysis and compare it to a standard PCR performed in a block-based thermocycler.

Activation of nuclear factor kappa B and cytokine imbalance in experimental alcoholic liver disease in the rat

Inflammatory stimuli and lipid peroxidation activate nuclear factor kappa B (NF-kappaB) and upregulate proinflammatory cytokines and chemokines. The present study evaluated the relationship between pathological liver injury, endotoxemia, lipid peroxidation, and NF-kappaB activation and imbalance between pro- and anti-inflammatory cytokines. Rats (5 per group) were fed ethanol and a diet containing saturated fat, palm oil, corn oil, or fish oil by intragastric infusion. Dextrose isocalorically replaced ethanol in control rats. Pathological analysis was performed and measurements of endotoxin were taken, lipid peroxidation, NF-kappaB, and messenger RNA (mRNA) levels of proinflammatory cytokines (tumor necrosis factor-alpha [TNFalpha], interleukin-1 beta [IL-1beta], interferon-gamma, [IFN-gamma], and IL-12), C-C chemokines (regulated upon activation, normal T cell expressed and secreted [RANTES], monocyte chemotactic protein [MCP]-1, macrophage inflammatory protein [MIP]-1alpha), C-X-C chemokines (cytokine induced neutrophil chemoattractant (CINC), MIP-2, IP-10, and epithelial neutrophil activating protein [ENA]-78), and anti-inflammatory cytokines (IL-10, IL-4, and IL-13). Activation of NF-kappaB and increased expression of proinflammatory cytokines C-C and C-X-C chemokines was seen in the rats exhibiting necroinflammatory injury (fish oil-ethanol [FE] and corn oil-ethanol[CE]). These groups also had the highest levels of endotoxin and lipid peroxidation. Levels of IL-10 and IL-4 mRNA were lower in the group exhibiting inflammatory liver injury. Thus, activation of NF-kappaB occurs in the presence of proinflammatory stimuli and results in increased expression of proinflammatory cytokines and chemokines. The Kupffer cell is probably the major cell type showing activation of NF-kappaB although the contribution of endothelial cells and hepatocytes cannot be excluded. Downregulation of anti-inflammatory cytokines may additionally exacerbate liver injury.

A sensitive, non-radioactive quantitative method for measuring IL-4 and IL-4delta2 mRNA in unstimulated cells from multiple clinical samples, using nested RT-PCR

Measurements of IL-4 mRNA directly from clinical samples are technically difficult as IL-4 is a low copy number cytokine. Moreover, most existing studies involving RT-PCR are confused by the use of primers which simultaneously amplify cDNA of IL-4 and its splice-variant (IL-4delta2). We describe a sensitive nested RT-PCR method to quantify mRNA expression of IL-4 and IL-4delta2 separately. It involves a simple method of generating cRNA standards without cloning. The use of external synthetic RNA standards, for which we validate that amplification kinetics are equivalent to the target, obviates the need for multiple sample dilutions. The assay is sensitive enough to measure IL-4 and IL-4delta2 mRNA expression in unstimulated PBMCs of normal subjects, and the reproducibility and throughput make this assay suitable for use in clinical studies with multiple samples.

Gamma interferon and interleukin-10 gene expression in synovial tissues from patients with early stages of Chlamydia-associated arthritis and undifferentiated oligoarthritis and from healthy volunteers

Genetically determined differences in interleukin-10 (IL-10) and gamma interferon (IFN-gamma) responses in mice correlate with clearance of Chlamydia pneumonitis infection. We measured the synovial expression of IL-10 and IFN-gamma and additional cytokine genes in patients who had recent-onset Chlamydia-associated arthritis (Chl-AA). IL-10 and IFN-gamma mRNA were relatively abundant in recent-onset Chl-AA.

RT-PCR quantitation of cytokine responses in vivo from specimens containing small numbers of cells during bioimmunotherapy

A Standard Template method has been developed to carry out semiquantitative RT-PCR analysis on mRNA extracted from small specimens that contain low yields of RNA. Using easily prepared templates (made from previously tested reference specimens), standard calibration curves were generated for each of two cytokine products of interest, specifically IL-10 and IFN-gamma. Also, internal standardization was accomplished by quantitating a well-characterized housekeeping gene (GAPDH). Simple densitometry of the RT-PCR product did not demonstrate sufficient reliability for quantitation since a logarithmic relationship was shown between product and template input. Peritoneal exudate cell specimens that were obtained from ovarian cancer patients during intraperitoneal immunotherapy were utilized for the demonstration of IL-10 and IFN-gamma transcript in vivo. Briefly, this method consists of: (1) template preparation: a PCR product for the cytokine of interest is generated from a previously identified positive specimen, purified and stored at -20 degrees C. (2) RT-PCR: cDNAs are produced from RNA extracted from patient specimens. Replicates of each cDNA and serial dilutions of the corresponding template are amplified with primers specific for each cytokine of interest. (3) Quantitation: photographs are made of the PCR products displayed on an agarose gel and are analyzed by densitometry. Determinations of fold-differences in cytokine transcript expression are normalized to the mRNA content of each specimen (based on the expression of GAPDH).

A flash-type bioluminescent immunoassay that is more sensitive than radioimaging: quantitative detection of cytokine cDNA in activated and resting human cells

Because of its high sensitivity, bioluminescence (BL) is an excellent alternative to radioactive quantitation of cytokine RT-PCR-derived products. BL also allows detection of amplicons at cycle numbers not normally detectable using radioactivity. No direct comparisons between these two methods have been made. In this study, the sensitivities of BL using recombinant aequorin, a flash-type luminescent tag capable of detecting signal to attomolar (10(-18) M) levels and radio imaging (RI) were directly compared. In addition, the application of BL for detecting cytokine message from biologic samples was examined. BL was 30- to 60-fold more sensitive than RI in detecting human IL-2 and CD3delta amplicons. This difference was particularly found during low cycle PCR, but was less at higher cycle numbers. The ability of BL to detect differences in cytokine message in stimulated and unstimulated human peripheral blood mononuclear cells was also evaluated. Using linear regression analysis, we observed up to 5,000-fold increases in RT-PCR amplified-mRNA in stimulated cells for IL-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-10 and GM-CSF compared to unstimulated cells. Changes in CD3delta, TNF alpha or IL-12 were not observed or quantitated. We present a novel aequorin-based application of bioluminescent technology to directly quantitate RT-PCR amplicons and to investigate the induction of human cytokine expression. Significant advantages of this sensitive bioluminescent method compared with radioactive methods are its abilities to quantitate amplicons in a PCR cycle range where linear detection is most robust and to analyze products in an automated, open-architecture microtiter plate format.