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U Andersson

Publications and source records attributed to U Andersson.

At least 91 records · Page 5Linked to original sources

Persistence of local cytokine production in shigellosis in acute and convalescent stages.

Shigella infection is accompanied by an intestinal activation of epithelial cells, T cells, and macrophages within the inflamed colonic mucosa. A prospective study was carried out to elucidate the cytokine pattern in Shigella infection linked to development of immunity and eradication of bacteria from the local site and also to correlate the cytokine profile with histological severity. An indirect immunohistochemical technique was used to determine the production and localization of various cytokines at the single-cell level in cryopreserved rectal biopsies from 24 patients with either Shigella dysenteriae type 1 (n = 18) or Shigella flexneri (n = 6) infection. The histopathological profile included presence of chronic inflammatory cells with or without neutrophils and microulcers in the lamina propria, crypt distortion, branching, and less frequently crypt abscesses. Patients had significantly higher (P < 0.005) numbers of cytokine producing cells for all of the cytokines studied, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1ra, tumor necrosis factor alpha (TNF-alpha), IL-6, IL-8, IL-4, IL-10, gamma interferon, TNF-beta, and transforming growth factor beta 1-3, in the biopsies than the healthy controls (n = 13). The cytokine production profile during the study period was dominated by IL-1 beta, transforming growth factor beta 1-3, IL-4, and IL-10. Significantly increased frequencies of cytokine-producing cells (P < 0.05) were observed for IL-1, IL-6, gamma interferon, and TNF-alpha in biopsies with severe inflammation in comparison with those with mild inflammation. During the acute stage of the disease, 20 of 24 patients exhibited acute inflammation in the rectal biopsies and the cellular infiltration was still extensive 30 days after the onset of diarrhea, although the disease was clinically resolved. In accordance with the histological findings, cytokine production was also upregulated during the convalescent phase; there was no significant difference (P > 0.05) in the incidence of cytokine-producing cells between acute (2 to 8 days after the onset of diarrhea) and convalescent (30 days after onset) stages.

Acute Disease↗

Down-regulation of gamma interferon, tumor necrosis factor type I, interleukin 1 (IL-1) type I, IL-3, IL-4, and transforming growth factor beta type I receptors at the local site during the acute phase of Shigella infection.

An immunohistochemical technique was used to examine whether there was a colocalization of cytokine-specific receptors with cytokine-expressing cells. We have previously shown that there is extensive cytokine production and secretion in the rectal mucosa in shigellosis (interleukin 1 alpha [IL-1 alpha], IL-1 beta, IL-1ra, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha [TNF-alpha], TNF-beta, gamma interferon, granulocyte-macrophage colony-stimulating factor, and transforming growth factor beta [TGF-beta]) (R. Raqib, A. A. Lindberg, B. Wretlind, P. K. Bardhan, U. Andersson, and J. Andersson, Infect. Immun. 63:289-296, 1995; R. Raqib, B. Wretlind, J. Andersson, and A. A. Lindberg, J. Infect. Dis. 171:376-384, 1995). Kinetics for receptor expression was compared with that for cytokine synthesis in the inflamed rectal mucosa from Shigella-infected patients during acute (2 to 6 days after onset of diarrhea) and convalescent (30 to 40 days after onset) stages. Quantification of receptor expression was assessed by computer-assisted analysis of video microscopic images. A selective down-regulation of the receptors for gamma interferon, tumor necrosis factor (TNF receptor [TNFR] type I), IL-1 (IL-1 receptor [IL-1R] types I and type II), IL-3, IL-4, and TGF-beta (TGF-beta receptor type I) was observed at the onset of the disease, with a gradual reappearance during the convalescent stage. However, IL-2R, IL-6R, granulocyte-macrophage colony-stimulating factor receptor, TNFR type II, and TGF-beta receptor type II showed no change in expression during the study period and were comparable to controls. Cytokine receptors were predominantly located to the epithelial layer of the mucosal surface and crypts, with variable expression patterns in the lamina propria. A time-dependent kinetic curve was seen for the soluble IL-2R (sIL-2R), sIL-6R, and sTNFR types I and type II shed in stool at the acute stage similar to that observed for cytokine secretion in stool but at four- to six-times-lower concentration. In contrast, soluble receptor levels in plasma were 100-fold higher than the cytokine levels. The results suggest a dissociation in immune regulation between cytokine production and cytokine receptor expression. The down-regulation of the receptors in acute shigellosis was probably a consequence of cytokine-induced internalization and shedding of the receptors during signal transduction as well as due to programmed regulatory roles played by cytokines and the bacterial antigens.

Acute Disease↗

Detection of cytokine producing cells in the synovial membrane from patients with rheumatoid arthritis.

OBJECTIVES: To develop and evaluate a new immunohistochemical method to study the localisation and phenotype of individual cytokine producing cells in synovial biopsy specimens in rheumatoid arthritis. METHODS: Cryopreserved sections of synovial tissue from nine patients with rheumatoid arthritis were incubated with carefully selected cytokine specific antibodies detecting 19 different cytokines, after fixation of the specimens with paraformaldehyde and using saponin to permeabilise the cell membranes. RESULTS: The immunohistochemical method yielded reproducible and distinct staining patterns, in which the cytokines accumulated mainly in the Golgi apparatus of producer cells, indicating that the method preferentially detected local synthesis rather than cytokine uptake. The cytokine production patterns varied considerably between biopsy specimens from different patients. CONCLUSION: The present modified immunohistochemical method may provide a simple and rapid way to determine the local production of a wide array of cytokines in the synovium. The data obtained with this method also indicated that more T cell derived cytokines than previously recognised were present in active synovitis, as located and sampled by arthroscopy.

Adult↗

Upregulated local cytokine production in recurrent tonsillitis compared with tonsillar hypertrophy.

In children with recurrent tonsillitis there may be persistent antigen deposition in tonsil tissue. even between exacerbations. If so, upregulation of immunocompetent cells should occur continuously, in contrast to tonsil tissue from children with tonsillar hypertrophy. The cytokine pattern was studied in cell suspensions prepared from tonsils obtained from 12 children undergoing tonsillectomy. The study group comprised 6 children with recurrent tonsillitis and 6 who had a history of tonsillar hypertrophy causing sleep apnea. Cytokine-producing cells (IL-1alpha, IL-1beta, TNFalpha, IL-6, IL-8, IL-2, IFNgamma, TNFbeta, IL-10 and IL-4) were characterized at the single-cell level by use of cytokine-specific monoclonal antibodies and indirect immunofluorescence technique. A constitutive production of IL-1alpha, IL-1beta, TNFalpha, and IL-8 was found in both groups (10-300/10(5) cells). However, the frequency of spontaneous IL-2, IFNgamma, TNFalpha, IL-6 and IL-10 was consistently low (10 +/- 10 cells) in both groups. Following restimulation by T-cell receptor ligation, using immobilized anti-CD3 mAb, with concentrations chosen so that it did not activate resting cells, increased frequencies of TNFalpha, IL-6, IL-8, IL-2, IFNgamma, IL-4 and 1L-10 synthesizing cells were induced in the recurrent tonsillitis group. Significantly higher incidences of IL-1beta, IL-6 and IL-2 producing cells were found in the recurrent tonsillitis group (60-200/10(5) cells, p <0.05). Microbiological evaluation in the tonsil tissue could not reveal tiny differences between the studied groups regarding bacterial or viral pathogens. However, this does not exclude persistent increased intracellular deposition of microbial antigens as a possible explanation for the elevated incidence of IL-1beta, TNF-alpha, IL-6, IL-8, IL-2, IFNgamma, IL-10 and IL-4 expressing cells noticed in patients with recurrent tonsillitis.

Cells, Cultured↗

Sequential production of Th1 and Th2 cytokines in response to live bacillus Calmette-Guérin.

Causes of individual variation in susceptibility to mycobacterial diseases are only partly understood. An efficient cell-mediated immune response is crucial for resistance. Macrophages and T cells interact to eliminate the mycobacteria, partially through the effects of secreted cytokines. A vigorous anti-bacterial inflammatory response is sometimes accompanied by severe tissue damage, while immunosuppression leads to progressive infection. Here, live, attenuated Mycobacterium bovis, bacillus Calmette-Guérin (BCG), was used as a model antigen to study cytokine production at the single-cell level in response to mycobacteria. Peripheral blood mononuclear cells from healthy individuals were challenged in vitro and the kinetics and frequencies of cytokine-producing cells were studied by immunofluorescent visualization of intracellular cytokines. Fourteen cytokines were assayed; interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), TNF-beta and granulocyte-macrophage colony-stimulating factor (GM-CSF). A sequential production of T helper-1 (Th1) and T helper-2 (Th2) cytokines was induced by BCG. Early, at days 1-2 after stimulation, the response was dominated by monokines and a low IFN-gamma and TNF-beta production. At days 4-5 there was a marked production of Th1 lymphokines, with approximately 6% IFN-gamma+ cells, 4% TNF-beta+ cells and 2% IL-2+ cells. Late in the reaction, at days 10-12, a Th2 response with IL-4, IL-5 and IL-10 was detected, while the synthesis of Th1 lymphokines and monokines declined. Overall, our results provide further evidence of IFN-gamma as the major cytokine induced by mycobacteria in healthy individuals, but also suggest that Th2 cytokines participate in the response.

Adult↗

Quantification of superantigen induced IFN-gamma production by computerised image analysis--inhibition of cytokine production and blast transformation by pooled human IgG.

A quantitative image analysis technique was developed to assess the cytokine content of immunocytochemically stained cytokine producing cells. Peripheral blood mononuclear cells were stimulated to induce cytokine production with the superantigen streptococcal pyrogenic exotoxin-A. We have developed a method based on indirect immunocytochemistry which identifies IFN-gamma producing cells by a characteristic morphology generated by the accumulation of IFN-gamma in the Golgi organelle. An image analysis technique permitted discrimination between these producer cells and IFN-gamma binding target cells, which showed a different appearance, with staining restricted to the cell surface membrane. A semi-automated routine programme allowed the signal from a video camera to be processed by computerised image analysis methodology. This enabled us to measure the number of cytokine producing cells, the cytokine staining intensity in individual cells and the cell size expressed in actual cell area. The incidence of IFN-gamma producing cells determined by image analysis measurement was compared to results obtained using manual microscopy. Cell size was assessed by the image analysis system as well as by flow cytometry. Administration of pooled human IgG for intravenous use (IVIg) to the superantigen stimulated cells significantly down-regulated IFN-gamma production, both in terms of the numbers of producer cells and in terms of cytokine staining intensity in individual cells. In addition blast transformation of cells was substantially reduced. These effects, mediated by IVIg, were also evident following delayed IVIg administration 24 h after the initial cell stimulation.

Adult↗

Lymphokine production induced by streptococcal pyrogenic exotoxin-A is selectively down-regulated by pooled human IgG.

The influence of pooled human IgG preparations for intravenous use (IVIg) on cytokine production induced by streptococcal pyrogenic exotoxin-A (SPE-A) was studied at the single-cell level using cytokine-specific monoclonal antibodies and indirect immunofluorescence or immunohistochemical staining. Mononuclear cells from healthy adult blood donors were stimulated with SPE-A alone or in the presence of IVIg. IVIg was added either prior to stimulation or 24 h after initiation of cultures, in an attempt to evaluate whether IVIg treatment could influence an already established systemic streptococcal disease. Cells were harvested after 48 or 72 h of culture and stained for the following cytokines: interleukin(IL)-1 alpha, IL-1 beta, IL-1ra, IL-6, IL-8, IL-2, tumor necrosis factor interferon(IFN)-gamma and TNF-alpha and TNF-beta and granulocyte macrophage-colony-stimulating factor. Stimulation with SPE-A lead to extensive lymphokine and monokine production. With the addition of IVIg prior to stimulation there was a strong reduction of blast transformation and an almost complete inhibition of lymphokine production, in particular in the synthesis of IFN-gamma and TNF-beta while the synthesis of IL-1 and IL-8 was either unaffected or increased. Adding IVIg 24 h after SPE-A stimulation also resulted in reduced blast transformation and decreased synthesis of IFN-gamma and TNF-beta. These results indicate an immunomodulatory potential by IVIg on streptococcally induced T cell activation and lymphokine production.

Adult↗

Cytokine synthesis analyzed at the single-cell level before and after revaccination with tetanus toxoid.

Tetanus toxoid (TT) is a potent immunogen which evokes strong antibody responses after immunization. Here, TT was used as a model antigen to study the production of cytokines at the single-cell level during the in vitro immune response to a specific recall antigen. Peripheral blood mononuclear cells were obtained from healthy volunteers before and 9 weeks after TT vaccination and were cultured with antigen in vitro. The kinetics of cytokine synthesis as well as frequencies of cytokine-producing cells were determined at the single-cell level by immunofluorescent intracellular staining of the cytokine protein. The phenotype of the producer cells was revealed by concomitant staining of surface markers. Two patterns of cytokine synthesis were induced by TT: (i) T lymphocytes expressed a number of lymphokines (interleukin (IL)-2, IL-3, IL-4, IL-10, interferon (IFN)-gamma and tumor necrosis factor (TNF)-beta), each with distinct kinetics of synthesis. This cytokine expression was strictly dependent on the previous exposure of the donor to TT and positively correlated with the level of tetanus immunity, as judged by TT-specific Ab levels in plasma as well as lymphoproliferation. Cells producing IL-2, IFN-gamma and particularly TNF-beta dominated this in vitro response. After 96-120 h in culture, 1.0-1.3% of the cells produced TNF-beta, i.e. frequencies at least tenfold higher than for any of the other lymphokines assayed. The addition of IL-2 to the cultures caused a fourfold increase and a kinetics shift in the production of TNF-beta, which peaked already at 24 h. Exogenously added IL-2 also caused a five- to tenfold increase in the number of IL-2 and IFN-gamma producers but no apparent change in the kinetics of intracellular lymphokine appearance. (ii) The cytokines IL-1 alpha, IL-1 beta, IL-6 and TNF-alpha were produced by monocytes. This inflammatory monokine response was independent of the TT-specific immune status of the donors, characterized by a rapid onset and was transient.

Adult↗

Local synthesis of both macrophage and T cell cytokines by synovial fluid cells from children with juvenile rheumatoid arthritis.

The production of tumour necrosis factor-alpha (TNF-alpha), TNF-beta and IL-6 in synovial fluid was studied in 50 samples of synovial fluid from 44 children with juvenile rheumatoid arthritis (JRA) by identifying cytokine production at a single-cell level. Post Ficoll-separated synovial fluid mononuclear cells were permeabilized and then intracellular TNF-alpha, TNF-beta and IL-6 protein production was examined using indirect immunofluorescence and murine anti-cytokine MoAbs. All three cytokines were measured in 37 of the 50 samples. In 25 of the 37 samples there was complete concordance; all three cytokines were present in six and absent in 19 samples. At least one cytokine was present in 27/50 (54%) of synovial fluid samples. Overall, TNF-alpha was detected in 22/49 (45%) samples, TNF-beta in 15/41 (37%) and IL-6 in 16/45 (36%) samples. Five patients had serial arthrocentesis, and in these samples there were two patients who had initially positive cytokine production, which on subsequent measurement was negative; in the other three patients there was no change from the previous cytokine production. We provide evidence that synovial fluid mononuclear cells produce monocyte and T cell cytokines in JRA. These findings suggest a role for both T cell and macrophage products in the pathogenesis of JRA, and the potential for modulation of cytokine production as a target for therapeutic intervention.

Adolescent↗

Similar cytokine induction profiles of a novel streptococcal exotoxin, MF, and pyrogenic exotoxins A and B.

The cytokine production induced by a newly discovered streptococcal exotoxin, MF, and the pyrogenic exotoxins SpeA and SpeB was determined by in vitro stimulation of peripheral blood mononuclear cells (PBMCs) obtained from healthy blood donors. The induction and kinetics of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, gamma interferon, tumor necrosis factor alpha (TNF-alpha), TNF-beta, and granulocyte-macrophage colony-stimulating factor were studied at the single-cell level by use of cytokine-specific monoclonal antibodies and intracellular immunofluorescent juxtanuclear staining. The cytokine-producing cells, with the exception of IL-1-expressing cells, had a characteristic morphology generated by the accumulation of cytokines in the Golgi organelle. MF, SpeA, and SpeB induced a massive gamma interferon and TNF-beta response in 10 to 16% of the PBMCs after 48 to 96 h of cell stimulation. In contrast, IL-2 and TNF-alpha production was detected in only 1 to 3% of the PBMCs. The induction of a lymphocyte TH2 phenotype response, including production of IL-3, IL-4, IL-5, and IL-10, was weak. However, the monokines, IL-1 alpha, IL-1 beta, IL-1 receptor antagonist, and IL-8, were consistently found and gradually produced, peaking at 24 h in approximately 5 to 8% of the PBMCs. MF showed extensive cytokine- and proliferation-inducing capacities equal to those of SpeA and SpeB, which suggests that MF is also a superantigen. A marked interindividual variation could be noted both in the proliferative response and in the cytokine induction of lymphocytes isolated from different individuals, which may be one explanation for the varying clinical severity noticed during group A streptococcal infections.

Bacterial Proteins↗

Serological follow-up after treatment of Borrelia arthritis and acrodermatitis chronica atrophicans.

To study the serological response to Borrelia burgdorferi after treatment of late Lyme borreliosis, consecutive serum samples from 20 patients with Borrelia arthritis and 21 with acrodermatitis chronica atrophicans were analysed with capture IgM ELISA and indirect IgG ELISA, both using B. burgdorferi flagella as antigen. Seven patients had positive IgM OD values, whereas all 41 had positive IgG OD values before therapy. In the majority, highly elevated IgG OD values were seen. All patients improved after antibiotic therapy, 32 recovering completely, while 9 had sequelae. At follow-up after 6 months to 5 years, 4/7 patients became negative IgM ELISA, whereas 3 still had slightly elevated IgM OD values 6 months, 1 year and 4.5 years, respectively, after therapy. Only one patient became negative in IgG ELISA during follow-up, although a significant decline in IgG OD values was seen in 22 of the remaining 40 initially IgG-positive patients. The serological response after successful treatment of Borrelia arthritis and acrodermatitis chronica atrophicans may persist for several years even with highly elevated IgG OD values in patients who have recovered completely.

Acrodermatitis↗

Concomitant in vivo production of 19 different cytokines in human tonsils.

Accumulating data indicate that cytokines, peptides involved in regulation of both physiological and pathological immune responses, are produced predominantly at the site of local antigen stimulation. Cytokine-producing cells were detected at the protein level in human tonsil tissue obtained from children with recurrent tonsillitis or infectious mononucleosis (IM). Concomitant production of 19 different human cytokines, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist (ra), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, tumour necrosis factor-alpha (TNF-alpha), TNF-beta, interferon-gamma (IFN-gamma) and transforming growth factor-beta 1-3 (TGF-beta 1-3), was identified at a single-cell level by indirect immunohistochemical staining procedures and use of carefully selected cytokine-specific antibodies (Ab). Fresh frozen sections were fixed with 4% paraformaldehyde and permeabilized by 0.1% saponin treatment, eluting cholesterol from the cell-surface membrane and the Golgi complex. The intracellular localization of all cytokines, except IL-1 and IL-1ra, was demonstrated by a characteristic local cytoplasmic perinuclear configuration in producer cells. In addition, the immunoreactivity for certain cytokines (IL-2, IL-4, IL-5, G-CSF and GM-CSF) was expressed on the cell membranes and extended over a large extracellular area encompassing the producer cell. Localization of the cytokine to the Golgi organelle was established by co-staining with a monoclonal antibody (mAb) specific to the Golgi complex. Both the extra- and intracellular cytokine staining reactions could be blocked by preincubation of the cytokine-specific Ab with the corresponding purified natural or recombinant cytokine. A complex cytokine pattern was established in both groups studied, where most T-helper type 1 (Th1) and Th2 lymphokines were expressed in the tonsils but at different frequencies and localizations. Cells expressing IL-4, IL-5, IL-10 and IL-13, (Th2 response) were evident at higher frequencies in recurrent tonsillitis compared to sections from IM, which were associated with a more pronounced IL-2, IFN-gamma and TNF-beta expression.

Acute Disease↗

Similar frequencies and kinetics of cytokine producing cells in murine peripheral blood and spleen. Cytokine detection by immunoassay and intracellular immunostaining.

Production of IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IFN-gamma, GM-CSF (granulocyte-macrophage colony stimulating factor) and macrophage colony stimulating factor by murine peripheral blood and spleen cells was analyzed following primary and secondary mitogen stimulation in vitro. Individual cytokine producing cells were detected by an intracytoplasmic staining technique. Cytokine production in cells from peripheral blood and spleen was comparable and more rapidly induced by calcium ionophore and phorbol 12-myristate 13-acetate than by concanavaling A. Restimulation in vitro induced both a swift production of cytokines and, for some cytokines, higher frequencies of producing cells. This was especially evident for IL-10 secreting cells, which increased 30-80 times in secondary responses. These analyses using the dual approaches of immunoenzymetric and fluorescent immunohistochemical techniques provide important evidence that cytokine induction kinetics can differ following primary or secondary stimulation.

Animals↗

Detection of intracellular interferon-gamma by light microscopy using an immunoperoxidase technique: correlation with the corresponding mRNA and protein product.

Identifying individual cytokine-producing cells may help to acquire insight into immunological processes. This study was designed to adapt a technique for the detection of individual cytokine-producing cells from an immunofluorescence to an immunoperoxidase staining procedure. The production of interferon-gamma (IFN-gamma) by anti-CD3-activated cloned human T cells was used as a model system. After the conditions for the staining procedure were optimized, the immunoperoxidase technique was slightly more sensitive than the immunofluorescence technique. The intracellular staining for IFN-gamma was preceded or paralleled by IFN-gamma mRNA production and followed by accumulation of IFN-gamma in the supernatant. It is concluded that intracellular IFN-gamma can easily be detected using an immunoperoxidase procedure. This procedure is highly sensitive and allows quantification of the production of multiple cytokines by counting the percentage of positively staining cells.

Cytokines↗

Characterization of cytokine production in infectious mononucleosis studied at a single-cell level in tonsil and peripheral blood.

Cytokine profile and production was studied at a single-cell level in cells obtained from 14 patients with acute infectious mononucleosis (IM), with less than 7 days of symptomatic disease, by use of cytokine-specific MoAbs and indirect immunofluorescence technique. In producer cells, all the studied cytokines, except IL-1, accumulated in the Golgi system, which resulted in a characteristic morphology of the staining. Less than one in a thousand mononuclear cells obtained directly from IM blood and stained within 2 h of sampling produced IL-2, interferon-gamma (IFN-gamma), IL-4, IL-5, IL-6, IL-10, GM-CSF, tumour necrosis factor-alpha (TNF-alpha) or TNF-beta, spontaneously. However, these cells were induced to cytokine synthesis by T cell receptor ligation in vitro using immobilized anti-CD3 MoAbs for 2-3 h restimulation under conditions which did not activate normal cells. By this approach 168 +/- 120 cells/10,000 peripheral blood mononuclear cells produced IFN-gamma as compared with 10 +/- 8 cells/10,000 non-stimulated cultured cells obtained from IM patients (P < 0.001) and 1/10,000 cells obtained from healthy controls, respectively. No induced production of IL-2, IL-3, IL-4, IL-5, IL-10, GM-CSF or TNF-beta was detected in IM cells obtained from peripheral blood by this restimulation. In contrast, a spontaneous cytokine production was evident in tonsil material obtained from four IM patients tonsilectomized because of respiratory obstruction. From this site 160 +/- 40 cells/10,000 cells produced IL-2, 40 +/- 30 cells IL-6, 30 +/- 30 cells TNF-beta and 35 +/- 25 cells IFN-gamma, respectively. No such spontaneous IL-2, IL-6, TNF-beta or IFN-gamma production was evident in control cells obtained from patients tonsilectomized because of chronic tonsil hyperplasia.

Adolescent↗

Selective cytokine production by epithelial cells following exposure to Escherichia coli.

This study compared the repertoire of cytokines produced by epithelial cell lines and human peripheral blood monocytes in response to Escherichia coli. The A-498 and J82 urinary tract epithelial cell lines and human peripheral blood monocytes were exposed to E. coli Hu734. The cytokine content of single cells was detected by indirect immunofluorescence using monoclonal antibodies to interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor alpha (TNF-alpha), TNF-beta, IL-6, IL-8, and granulocyte macrophage-colony-stimulating factor, and the number of positive cells was used to quantitate the response. The J82 bladder cell line stained positive for IL-6, IL-8, and IL-1 alpha. The IL-8 and IL-6 response peaked at 2 h, while the number of IL-1 alpha-positive cells reached a peak 6 h after E. coli stimulation. The A-498 kidney cell line stained for IL-8 with a peak at 2 h and IL-6 with a peak at 6 h after E. coli stimulation. Peripheral blood monocytes stained for the cytokines IL-1 alpha, IL-1 beta, IL-8, IL-6, and TNF-alpha but not for TNF-beta and granulocyte macrophage-colony-stimulating factor after stimulation with E. coli. The results demonstrated that bacteria activated a cytokine response in the epithelial cell lines and monocytes. The epithelial cell lines had a more limited cytokine response profile than circulating monocytes, which may serve to limit the consequences of microbial exposure at the mucosal surface and help maintain the integrity of other tissue compartments.

Adult↗

Cytokine production in mononuclear cells of human milk studied at the single-cell level.

In this study, we demonstrate that mononuclear cells of human milk have a potential for production of many different cytokines. We applied a technique for cytokine detection at the single-cell level using cytokine specific MAb and immunofluorescence. The characteristic staining pattern obtained represents intracellular cytokine production, which allows for the assessment of the cellular origin of production. Milk mononuclear cells were mitogen-stimulated in vitro and cultured for 4 h and then stained for 13 cytokines. Lipopolysaccharide stimulation induced extensive production of the following monokines: IL-1 alpha, IL-1 beta, IL-1ra, IL-6, IL-8, and tumor necrosis factor-alpha. IL-10 and granulocyte-macrophage colony-stimulating factor were smaller products, although detectable in most samples. The abundant monokine production correlated with the high number of macrophages in milk. Spontaneous monokine production in unstimulated cells could be detected in six out of 11 samples. The highest incidence was evident for IL-8. No spontaneous lymphokine production was detected. Considering the low proportion of lymphocytes, stimulation with phorbol myristate acetate in combination with ionomycin resulted in considerable production of the following lymphokines: IL-2, IL-3, IL-4, IL-10, interferon-gamma, tumor necrosis factor-alpha. Macrophages contributed to the high production of tumor necrosis factor-alpha and GM-CSF. IL-5 synthesis was detectable in only one sample. This work reveals that human milk mononuclear cells are potent producers of cytokines when mitogen stimulated in vitro. The in vivo implications of these findings remain to be investigated further.

Antibodies, Monoclonal↗