Characterization of cytokine gene expression in CD4+ and CD8+ T cells after activation with phorbol myristate acetate and phytohaemagglutinin

Spontaneous inflammatory cytokine gene expression in normal human peripheral blood mononuclear cells

Cytokines regulate cellular immune activity and are produced by a variety of cells, especially lymphocytes, monocytes, and macrophages. Measurement of cytokine levels has yielded useful information on the pathological process of different diseases such as AIDS, endotoxic shock, sepsis, asthma, and cancer. It may also be of use in the monitoring of disease progression and/or inflammation. To determine spontaneous cytokine gene expression in whole blood and PBMCs, whole blood was obtained from healthy volunteers and total mRNA was isolated from PBMCs. The kinetics of response were determined by sequential testing of cytokine gene expression by RT-PCR analysis. Our results demonstrated that isolated and incubated PBMCs expressed TNF-alpha and high levels of IL-1beta, IL-6, IL-8, and IL-10. In contrast, WB only expressed the mRNA cytokines of TNF-alpha and IL-8 (p < 0.05). These results suggest that spontaneous myriad mRNA cytokine expression can be avoided with the use of WB incubation and the rapid collection of PBMCs. Furthermore, this method should be employed in all cases where the levels of cytokine gene expression can be evaluated.

Changes in immune regulation in response to examination stress in atopic and healthy individuals

BACKGROUND

Stress can aggravate the allergic inflammation, but determinants of disturbed immune regulation are largely unknown.

OBJECTIVE

To determine systemic immunological, local inflammatory and functional airway responses to stress in healthy and atopic individuals.

METHODS

Forty-one undergraduate students, 22 with allergy of whom 16 had asthma, and 19 healthy controls, were studied in a low-stress period and in association with a large exam. Subjects completed questionnaires on stress and health behaviours, underwent lung function tests, bronchial methacholine challenge, measurements of exhaled nitric oxide and urine cortisol. Blood cells were phenotyped, and cytokines from mononuclear blood cells were analysed.

RESULTS

Perceived stress and anxiety increased in both groups during the exam period while cortisol increased only in the atopy group. Cytokine production decreased broadly in response to stress in both groups, which was paralleled by an increase in the proportion of regulatory T cells (CD4(+)CD45RO(+)CD25(bright)). Interestingly, atopic individuals, but not controls, reacted with a decreased T-helper type 1/T-helper type 2 (Th1/Th2) ratio and a decrease in natural killer (NK) cell numbers in response to stress. In control subjects only, exhaled nitric oxide decreased and forced expiratory volume in one second increased during stress.

CONCLUSION

Atopic and non-atopic subjects shared some immune changes in response to stress, such as a dramatic decline in cytokines and an increase in the number of regulatory T cells in peripheral blood. However, other stress-induced immune changes were unique to atopic individuals, such as a skewed Th1/Th2 ratio and reduced NK cell numbers, indicating that some pathogenic mechanisms in atopics may be more strongly affected by stress than others.

Interleukin-2 immunotherapy exerts a differential effect on CD4 and CD8 T cell dynamics

BACKGROUND

Emerging evidence indicates that CD4 and CD8 T cell recovery is differentially regulated during HIV infection. The hallmark of interleukin-2 (IL-2)-induced immune reconstitution is the selective outgrowth of CD4 through undefined mechanisms.

OBJECTIVE

To delineate the effect of IL-2 on T cell homeostasis by analysing the differential impact of IL-2 immunotherapy on CD4 and CD8 dynamics.

DESIGN

A randomized trial of 15 HIV-positive patients, eight receiving IL-2 immunotherapy with highly active antiretroviral therapy (HAART) and seven with HAART alone. Patients were followed for a 48-week period following three IL-2 cycles (overall, 10 weeks in duration).

METHODS

CD4 and CD8 count, naive and memory immunophenotype, proliferation by Ki67, and CD8+CD38+ activated pattern were measured longitudinally by flow cytometry. Thymic output contribution to both CD4 and CD8 was evaluated by measurement of T cell receptor excision circles (TREC). Wilcoxon test was used to compare results.

RESULTS

Compared with changes seen with HAART alone, IL-2 induced a more significant rise in CD4 than CD8 T cell count (P < 0.01), associated with a significant increase in Ki67-proliferating CD4 (P < 0.05), whereas no changes were seen in CD8+Ki67+ (P > 0.05). Furthermore, IL-2 administration was associated with CD4 TREC increase, whereas CD8 TREC remained stable (P > 0.05). Modifications in CD4 and CD8 T cells seen in patients taking only HAART were not associated with changes in CD4 and CD8 TREC.

CONCLUSIONS

By showing a differential impact on CD4 and CD8 homeostasis, the study suggests that IL-2-associated immune reconstitution results from protean interactions between T cell compartments; this has significant implications for the correct planning of immunotherapeutic strategies.

Plasma and in vitro levels of cytokines during and after a Plasmodium falciparum malaria attack in Gabon

Fifty subjects living in a malaria endemic area were studied at diagnosis of a Plasmodium falciparum attack and 3 weeks later. Absolute numbers of CD3(+), CD4(+) and CD8(+) lymphocytes as well as plasma cytokines and secreted cytokines after in vitro mitogenic stimulation were measured. At enrollment, lymphopenia was observed, lending support to the reallocation hypothesis during the acute phase. A significant elevation of the number of CD8(+) cells was present in the peripheral blood during the recovery phase. During the acute phase, plasma IL-6 levels peaked while in vitro production capacity was high at both phases. Plasma IL-6 concentrations were positively related to blood parasite density at D0, as IL-4 and IFN-gamma, suggesting an early intervention of these cytokines. Plasma IL-2 levels were low at diagnosis although cells retained their ability to produce IL-2, which was found more frequently in plasma after cure. Acquisition of immunity with age was in relation with greater secretion abilities of cells for type 1 and type 2 cytokines during the parasite clearance phase. We conclude to an early implication of type 2 cytokines and IFN-gamma, with particularly high levels of IL-6.

Decreased IL-12 production by polymorphonuclear leukocytes in patients with active systemic lupus erythematosus

Polymorphonuclear leukocytes (PMN) play an important role in eradicating bacterial infections. To test if PMN of patients with systemic lupus erythematosus (SLE) have defective capacity to produce IL-12, IL-12 p35 gene transcription and p70 excretion by PMN were evaluated in SLE patients and normal subjects. Peripheral blood PMN from 25 patients with active SLE and 25 normal individuals were stimulated with lipopolysaccharide (LPS, 100ng/mL) in the presence or absence of recombinant interferon (IFN)-gamma (5-200IU/mL). The IL-12 p35 gene transcripts were analyzed by reverse transcription - polymerase chain reaction (RT-PCR) and the IL-12 p70 in culture supenatants was quantified by enzyme immunoassay (EIA). At the 6th hour of stimulation, IL-12 expression in PMN of SLE patients was less prominent than that of the normal controls. The IL-12 was produced by normal PMN on LPS stimulation in the absence of IFN-gamma. IFN-gamma enhanced the IL-12 production by normal PMN stimulated with LPS, but it inhibited the IL-12 production in PMN from active lupus patients in the presence of LPS. Analysis with PCR using the same primers on the chromosomal DNA showed that p35 gene was intact in SLE patients. These results have suggested that SLE-PMN may have defect in IL-12 expression and the defect may be exaggerated in the presence of IFN-gamma which normally stimulates IL-12 production. This may account for increased susceptibility to multiple infections in patients with active SLE.

Cytokine expression in unstimulated PBMC of children with type 1 diabetes and subjects positive for diabetes-associated autoantibodies

The aim of this study was to evaluate possible changes in the circulating levels of interferon (IFN)-gamma, interleukin (IL)-4 and transforming growth factor (TGF)-beta in association with the autoimmune process leading to type 1 diabetes. Expression levels of mRNAs specific for each cytokine were determined in peripheral blood mononuclear cells (PBMC) by a multiplex reverse transcription-polymerase chain reaction (RT-PCR) followed by hybridization reactions with lanthanide-labelled probes and detection by time-resolved fluorometry. Newly diagnosed diabetic children had lower levels of IFN-gamma, IL-4 and TGF-beta 1 signals compared to their age- and sex-matched controls (P < 0.02, P < 0.005 and P < 0.005, respectively) and also the autoantibody-positive subjects had significantly lower levels of IL-4 and TGF-beta 1 in comparison with their matched controls (P = 0.0013 and P = 0.012). No significant differences were observed when comparing matched pairs of diabetic children and autoantibody-positive subjects. Our results suggest a systemic bias towards reduced production of T-helper cell type 2 cytokines (IL-4 and TGF-beta 1) during the autoimmune process, but there was also a reduced level of IFN-gamma expression in the periphery at the onset of clinical diabetes.

Increased secretion of TGF-beta1 by peripheral blood mononuclear cells from patients with Type 1 diabetes mellitus with diabetic nephropathy

AIMS

To study transforming growth factor (TGF)-beta1 secretion by peripheral blood mononuclear cells (PBMC) from Type 1 diabetic patients with and without nephropathy.

METHODS

Thirty normoalbuminuric Type 1 diabetic patients (urinary albumin excretion rate (AER) < 20 microg/min), 12 microalbuminuric (AER 20-200 microg/min), 10 nephropathic (AER > 200 microg/min), and 13 non-diabetic individuals were recruited. TGF-beta1 secretion by PBMC was measured by enzyme immunoassay (EIA) after 48 h culture with and without phytohaemagglutinin (PHA) (5 microg/ml).

RESULTS

After 48 h culture, the highest TGF-beta1 levels secreted by unstimulated PBMC were found in patients with nephropathy (median 6.2 (range 0.9-20.0) ng/ml) when compared to patients with normal albumin excretion (4.1 (0.2-11.3) ng/ml), microalbuminuria (1.8 (0.2-6.4) ng/ml) and healthy controls (1.0 (0.2-7.0) ng/ml); P = 0.02 for the three diabetic groups and P = 0.006 for all groups. At 48 h, the PHA-stimulated TGF-beta1 levels were 12.4 (2.9-30.0) ng/ml in nephropathic, 7.3 (0.5-21.2) ng/ml in normoalbuminuric, and 5.5 (0.5-27.6) ng/ml in microalbuminuric patients (P = 0.05). A correlation was observed between TGF-beta1 and diastolic blood pressure in the subgroup of patients with incipient and overt nephropathy (r = 0.45, P = 0.04).

CONCLUSIONS

Type 1 diabetic patients with overt nephropathy show increased TGF-beta1 secretion by PBMC. Diastolic blood pressure levels correlated with TGF-beta1 secretion in diabetic patients with nephropathy. Increased TGF-beta1 secretion by PBMC may be associated with renal and vascular disease in Type 1 diabetes mellitus.

Modulation of peripheral blood mononuclear cell activation status during Salmonella-triggered reactive arthritis

OBJECTIVE

To determine the activation status of mononuclear cells in the peripheral circulation during the acute phase and the recovery phase of Salmonella-triggered reactive arthritis (ReA).

METHODS

Peripheral blood mononuclear cells (PBMC) were obtained from 8 patients with Salmonella infection (4 with ReA and 4 without) and were studied by reverse transcription-polymerase chain reaction for messenger RNA (mRNA) of proinflammatory and antiinflammatory cytokines, by flow cytometry (FC) for cell surface activation and adhesion molecules, by immunofluorescence (IF) microscopy for bacterial antigens, and by FC, IF, and DNA fragmentation on gel for signs of apoptosis.

RESULTS

During the acute phase of the infection, PBMC were activated in all patients, as characterized by high levels of expression of CD14, CD11b, and CD11c on monocytes. In the patients with ReA, PBMC also had the capacity to produce interleukin-1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor alpha. During the amelioration of disease, monocyte activation was decreased in all patients. A complete down-regulation of CD14 was detected only in the patients with ReA, whereas the expression of CD14 in the patients without ReA was positive and was similar to that in healthy controls. In addition, cytokine mRNA levels decreased regardless of the presence of Salmonella antigens in blood cells in all 4 patients with ReA.

CONCLUSION

High levels of expression of some activation and adhesion molecules and elevated levels of mRNA for certain cytokines that are predominantly produced by monocytes were found in PBMC from patients with acute Salmonella-triggered ReA, which suggests that these cells are activated. On the other hand, complete down-regulation of CD14 and a marked decrease in the cytokine production capacity during amelioration of the disease suggest that suppression of PBMC activity might be involved in recovery from ReA.

Expression of interleukin-10 in isolated CD8+ T cells and monocytes from growth factor-mobilized peripheral blood stem cell products: a mechanism of immune dysfunction

Previous reports showed the abnormal activation of immune cells in growth factor-mobilized peripheral blood stem cell (PBSC) products, which might be responsible for depressed T cell responsiveness to mitogens compared with normal peripheral blood mononuclear cells (PBMC). In the present study, the mRNA expression levels of interleukin (IL)-2, IL-4, IL-10, and interferon-gamma (IFN-gamma) were significantly higher in CD4+ and CD8+ T cells from mobilized PBSC products compared with CD4+ and CD8+ cells from normal peripheral blood (PB). The mRNA expression levels of IL-4 and IL-10 were significantly higher in CD8+ compared with CD4+ cells from PBSC products. However, the expression of IL-2 and IFN-gamma mRNA transcripts was similar in the CD4+ and CD8+ T cells from PBSC products. The levels of IL-10, IL-8, and tumor necrosis factor (TNF)-alpha mRNA were also significantly higher in monocytes isolated from PBSC products compared with monocytes isolated from normal PB. Expression of IL-10-specific mRNA in monocytes also was significantly higher than the levels observed in CD8+ cells from PBSC products. We suggest that both CD4+ and CD8+ cells in the PBSC products are highly activated. However, their response to phytohemagglutinin (PHA) mitogenesis is depressed in part because of IL-10 expression by CD8+ cells and monocytes in addition to the higher levels of monocyte-dependent T cell inhibitory activity. These data demonstrate that aberrant IL-10 expression in the CD8+ T cells and monocytes present in PBSC products may represent a possible mechanism of immune dysfunction in patients after high-dose chemotherapy (HDT) and peripheral blood stem cell transplantation (PBSCT).

Gene expression and synthesis of natriuretic peptides by cultured human glomerular cells

BACKGROUND

Atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide belong to a family of hormones that have natriuretic and vasodepressor activity and may play a pathophysiologic role in hypertension, heart failure and renal failure. Whereas immunoreactive human forms of these three natriuretic peptides are found in renal tubules, it is not clear whether they are derived from the systemic circulation or from local production.

OBJECTIVE

To examine the gene expression of natriuretic peptides in cultured human glomerular cells.

MATERIALS AND METHODS

We sought to determine the presence of messenger RNA encoding for these natriuretic peptides using polymerase chain reaction following reverse transcription. The polymerase chain reaction products were confirmed by direct sequencing. Atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide in cell-culture supernatants were measured by radioimmunoassays (with detection limits of 2.1, 2.1 and 0.21 pmol/l, respectively).

RESULTS

Atrial natriuretic peptide messenger RNA was not found in mesangial or glomerular epithelial cells (despite stimulation with tumor necrosis factor-alpha) except when the cells were cultured with a high concentration of fetal bovine serum (> 10%). Similarly, this peptide was not detected in supernatant unless the cells were cultured with fetal bovine serum at concentrations of > 10%. Brain natriuretic peptide messenger RNA was readily detected in cultured mesangial and glomerular epithelial cells with a lower concentration in the former. Brain natriuretic peptide was not found in the supernatant of resting mesangial cells but became detectable when incubated with tumor necrosis factor-alpha or fetal bovine serum. C-type natriuretic peptide messenger RNA was detected in mesangial and glomerular epithelial cells with a higher concentration in the latter. C-type natriuretic peptide was detected in the supernatant of resting glomerular epithelial cells and levels rose when incubated with increasing concentrations of tumor necrosis factor-alpha or fetal bovine serum. However, C-type natriuretic peptide was not detected in the supernatant of resting mesangial cells and remained undetectable following incubation with tumor necrosis factor-alpha or fetal bovine serum.

CONCLUSION

Our results suggest differences in the synthesis of natriuretic peptides between glomerular mesangial and epithelial cells.

Cytokine mRNA expression and proliferative responses induced by pertussis toxin, filamentous hemagglutinin, and pertactin of Bordetella pertussis in the peripheral blood mononuclear cells of infected and immunized schoolchildren and adults

Pertussis infection is increasingly recognized in older children and adults, indicating the need of booster immunizations in these age groups. We investigated the induction of pertussis-specific immunity in schoolchildren and adults after booster immunization and natural infection. The expression of mRNA of gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-5 in the peripheral blood mononuclear cells (PBMCs) was assayed by reverse transcription-PCR. The PBMCs of 17 children immunized with one dose of an acellular vaccine containing pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin (PRN) significantly proliferated in vitro after stimulation with the vaccine antigens. The PBMCs of seven infected individuals markedly proliferated in the presence of PT and FHA, but the cells of only two of these subjects responded to PRN. At least one of the antigens induced mRNA for IL-4 and/or IL-5 in the cells of 93% of tested vaccinees and patients, and FHA induced IFN-gamma mRNA in the cells of two-thirds of them. Expression of mRNA for IFN-gamma correlated with the production of the cytokine protein. Anti-FHA immunoglobulin G antibodies significantly correlated with FHA-induced proliferative responses both before and after immunization. These results show that booster immunization with acellular pertussis vaccine induces both antibody- and cell-mediated immune responses in schoolchildren. Further, booster immunization and natural infection seem to induce the expression of mRNA of T-helper 1 (Th1) and Th2 type cytokines in similar manners. This observation supports the use of acellular pertussis vaccines for booster immunizations of older children, adolescents, and adults.

The interleukin-5 messenger RNA expression in a patient with idiopathic hypereosinophilic syndrome

Interleukin-5 has a specific role in various eosinophilic activities. It is the predominant cytokine produces by activated T-lymphocytes isolated from patients with idiopathic hypereosinophilic syndrome. We studied a young patient suffering from idiopathic hypereosinophilic syndrome who presented with Horner's syndrome, peripheral neuropathy and skin ulcers. The IL-5 gene expression by CD4+ T-lymphocytes and the peripheral eosinophil count were raised. The skin ulcers continued to deteriorate despite a swift reduction of the IL-5 gene expression and peripheral eosinophil count following systemic corticosteroid treatment. We suggest that peripheral eosinophilia may not be responsible for the damage in skin lesions and more aggressive treatment may be required.

Cytokine gene expression in normal human lymphocytes in response to stimulation

Sequential gene expression of two type 1 cytokines (interleukin 2 [IL-2] and gamma interferon), one type 2 cytokine (IL-10), two monokines (IL-6 and tumor necrosis factor alpha), and one cytokine receptor (IL-2 receptor [IL-2R]) in normal human peripheral blood mononuclear cells (PBMC) following in vitro stimulation was investigated by reverse transcription-PCR methods. Two stimuli were utilized: phytohemagglutinin (PHA), which acts on the CD2 molecule and T-cell receptors, and anti-CD3 monoclonal antibody, which acts on the CD3 molecule and on T-cell receptors. Increased expression of all studied genes occurred between 1 and 4 hours after stimulation, except for that of the gene encoding IL-10, which was delayed. Expression of all but one of the genes was transient, with a maximal mRNA accumulation at about 8 h on average. IL-2R mRNA expression was an exception, showing a prolonged increase (72 h). The general profiles of expression of the five cytokine genes were similar but not identical, suggesting some shared regulatory mechanisms. When responses to four additional stimuli (pokeweed mitogen, Candida albicans, and IL-2 at high and low doses) were compared, similar profiles of cytokine gene expression were found. Thus, the various stimuli caused induction of all cytokines with quantitative, not qualitative, differences. Altogether, the present data are useful for defining the kinetics of gene expression for key cytokines in response to standard immune-cell stimuli.

Gene expression of the renin-angiotensin system in human kidney

BACKGROUND

Immunocytochemical studies have revealed that all components of the renin-angiotensin system are widely distributed in human tissues yet the information on the gene expression of the renin-angiotensin system in various types of cell remains scarce.

OBJECTIVE

We explored the presence of a local renin-angiotensin system in human kidney.

METHODS

We sought to determine the presence of messenger RNA (mRNA) encoding for renin, angiotensinogen, and angiotensin converting enzyme (ACE) in cultured human glomerular cells and human umbilical vein endothelial cells using a two-step polymerase chain reaction. The gene expression of the renin-angiotensin system in normal human kidney and in diseased kidney was studied by in-situ hybridization using synthetic oligonucleotides.

RESULTS

By using a two-step polymerase chain reaction, renin, angiotensinogen, and ACE mRNA were found in cultured mesangial and epithelial cells but only ACE mRNA was present in human umbilical vein endothelial cells. Renin mRNA was detected in juxtaglomerular granular cells and also in glomerular and tubular epithelia in normal kidney by in-situ hybridization. A similar tubular, but not mesangial, distribution was found with angiotensinogen and ACE mRNA. In contrast, stronger signals for renin, angiotensinogen and ACE mRNA were detected in mesangial and epithelial cells of kidney tissues from hypertensive patients and from patients with renal pathology characterized by mesangial proliferation (immunoglobulin A nephropathy, diabetes mellitus, or lupus nephritis).

CONCLUSIONS

That gene expression of the renin-angiotensin system occurs in resident glomerular cells supports the hypothesis that there is a local renin-angiotensin system in human kidney. Our findings support the previous speculation that the renin-angiotensin system could be a local factor involved in the progression of chronic renal failure and consequent development of hypertension.

Cytokine profiles of stimulated blood lymphocytes in asthmatic and healthy adolescents across the school year

T cell cytokines play an important role in mediating airway inflammation in asthma. The predominance of a Th2 cytokine profile, particularly interleukin (IL)-4 and IL-5, is associated with the pathogenesis and course of asthma. The aim of this study was to test the hypothesis that a stressful life event alters the pattern of cytokine release in asthmatic individuals. Thirteen healthy controls and 21 asthmatic adolescents gave blood samples three times over a semester: midsemester, during the week of final examinations, and 2-3 weeks after examinations. Interferon-gamma (IFN-gamma), IL-2, IL-4, and IL-5 were measured from supernatants of cells stimulated with PHA/PMA for 24 h. Cells from asthmatic subjects released significantly more IL-5 during the examination and postexamination periods, whereas cells from healthy controls released significantly more IL-2 during the midsemester and examination periods, thereby indicating a bias for a Th2-like pattern in asthmatics and a Th1-like pattern in healthy controls. IL-4 and IL-5 production showed a marked decrease during and after examinations in healthy controls, whereas this decline was absent in asthmatics. The ratios of IFN-gamma:IL-4 and IFN-gamma:IL-5 also revealed significant changes in the profile of cytokine release across the semester. These results indicate differential cytokine responses in asthmatics that may become pronounced during periods of cellular activation.

Kinetics of IL-2 and IL-4 mRNA and protein production by graft-infiltrating lymphocytes responsible for rejection after clinical heart transplantation

During cardiac rejection we studied the kinetics of IL-2 and IL-4 mRNA and subsequent protein production by in vivo primed graft-infiltrating lymphocytes (GIL), using semiquantitative RT-PCR and ELISA. Following in vitro stimulation with either donor or third-party antigens, mRNA expression of IL-2 and IL-4 were already detectable 1-2 h after stimulation, while their protein production could be measured from 4 h onwards at least until 48 h. At both the mRNA and protein level, we measured a donor-specific signal for IL-2 and for IL-4 production (p = 0.02), while the relative donor-specific IL-2 mRNA level was significantly higher than the relative IL-4 mRNA level (p = 0.002). These observations suggest that after in vitro challenge with donor antigens, GIL obtained from rejecting cardiac allografts predominantly produce IL-2 mRNA and protein.

Cytokine gene expression profile of circulating CD4+ T cells in active pulmonary tuberculosis

T lymphocytes, particularly CD4+ cells, are thought to play an important role in the immune defense against Mycobacterium tuberculosis through the release of their wide array of cytokines. In vitro studies suggest that Mycobacterium-specific T-cell clones are of the TH1 subtype. Using the technique of reverse transcription-polymerase chain reaction, we have investigated the capacity for cytokine gene expression profile in ex vivo circulating CD4+ T cells from 20 patients with active pulmonary tuberculosis compared with that of 30 normal healthy tuberculin-positive volunteers. Venous blood samples were collected from the former prior to the initiation of chemotherapy. A significant increase in interleukin (IL-2) expression (p < 0.001) and a significant decrease in IL-5 expression (p < 0.0001) were observed in patients with tuberculosis but no differences were seen in the expression of IL-4 and interferon gamma between the two study groups. Our data support a TH1-like immune response in active tuberculosis.

Detection of hepatitis B virus DNA and RNA in kidneys of HBV related glomerulonephritis

Glomerular deposition of hepatitis B virus (HBV) antigens are observed in chronic HBsAg carriers with different glomerulonephritides yet the etiologic role of HBV remains uncertain. We examined the paraffin section of kidney biopsies from 40 chronic HBsAg carriers with membranous nephropathy (MGN), mesangiocapillary glomerulonephritis (MCGN) or IgA nephropathy (IgAN) for HBV DNA and HBV RNA using in situ hybridization (ISH). Glomerular HBV antigens were present in all biopsies by immunofluorescence. HBsAg or HBcAg mRNA was also studied in RNA extracted from frozen renal tissue using a two-step polymerase chain reaction (PCR) following reverse transcription (RT). HBcAg DNA was not easily detected with ISH alone, but was readily found in 31 biopsies (78%) following PCR. HBV DNA was detected mainly in the cytoplasm of proximal tubular epithelia but not in glomerular cells. HBsAg and/or HBcAg mRNA were detected by RT-PCR in extracted RNA from 13 biopsies (33%). The PCR findings were further confirmed by (a) Southern blot hybridization using a cloned HBV probe and (b) absence of PCR product following treating RNA with RNase or omitting the RT. It is plausible that HBV DNA in renal tubules represents endocytosis of HBV DNA in the urinary filtrate and the HBV RNA extracted from kidney biopsies could derive from infiltrating cells bearing HBV RNA. Hence, ISH with specific HBV core gene RNA probe was performed subsequently. HBcAg RNA, localized in the nuclei and cytoplasm of glomerular and tubular cells, was detected in 56%, 20%, and 36% of renal biopsies in chronic HBsAg carriers with MGN, MCGN, and IgAN, respectively. Our findings indicate the presence of viral transcription in glomerular cells and renal tubular epithelia, supporting an etiological role of HBV in some chronic HBsAg carriers who develop coexisting glomerulonephritides.

Interleukin-5 messenger RNA expression in peripheral blood CD4+ cells in asthma

BACKGROUND

IL-5 has been implicated in the pathogenesis of asthma through its regulatory role on eosinophil survival, proliferation, and effector function.

OBJECTIVE

The study was designed to investigate the relationships between IL-5 messenger RNA expression in circulating CD4+ cells and serum concentrations of eosinophil cationic protein (ECP), a marker of eosinophil activation, and disease activity in asthma.

METHODS

IL-5 gene expression was assessed semiquantitatively in ex vivo stimulated CD4+ cells by reverse transcription-polymerase chain reaction and serum ECP concentration measured from venous blood samples collected from patients with acute severe asthma before the commencement of systemic steroid therapy (day 1) and on day 7 and from patients with stable asthma and healthy volunteers.

RESULTS

IL-5 gene expression was significantly higher in patients with acute asthma before steroid treatment than in those with stable disease and healthy subjects (p < 0.0001). Similar results were obtained with serum ECP levels: levels in patients with acute asthma were highest (20.30 +/- 5.31 micrograms/L), followed by levels in patients with stable asthma (2.76 +/- 0.65 micrograms/L) and levels in normal control subjects (1.37 +/- 0.06 micrograms/L; p < 0.01 for all comparisons). Significant falls in both IL-5 expression and serum ECP level were seen on day 7 (p < 0.001) and coincided with a significant improvement in peak expiratory flow (p < 0.0001). Significant correlations were observed between IL-5 expression and ECP level (rho = 0.39, p < 0.01), IL-5 expression and peak expiratory flow (rho = -0.55, p < 0.0002), and peak expiratory flow and ECP level (rho = -0.32, p < 0.04).

CONCLUSION

Our data therefore support an important regulatory role of IL-5 on eosinophil function in human asthma in vivo.

Transforming growth factor-beta mRNA expression in CD4+ T cells from patients with primary glomerulonephritides

Immunoreactivity to transforming growth factor-beta (TGF-beta) was detected in glomerular cells from patients with chronic glomerulonephritis, yet it remains uncertain whether the glomerular TGF-beta deposits reflect TGF-beta produced by the glomerular cells alone or from additional extrarenal origin. We examined the TGF-beta messanger RNA (mRNA) expression in circulating CD4+ T cells from 45 patients with different primary glomerulonephritides. By semiquantitative polymerase chain reaction, the TGF-beta mRNA expression was significantly raised in histopathologic entities characterized by increased mesangial proliferation or segmental sclerosis but not in histopathologic entities with little mesangial proliferation or sclerosis. These findings suggest that, other than TGF-beta produced de novo, TGF-beta from systemic source can also contribute to mesangial proliferation by binding to the glomerular cells after being filtered by the glomeruli. Increased TGF-beta gene expression in CD4+ T cells in these patients may potentially enhance glomerular injury.

Gene expression of interleukin-3 and granulocyte macrophage colony-stimulating factor in circulating CD4+ T cells in acute severe asthma

BACKGROUND

Interleukin (IL)-3 and granulocyte macrophage colony-stimulating factor (GM-CSF) may influence the inflammatory process in asthma through their regulatory role on eosinophil survival, differentiation and effector function.

OBJECTIVE

To examine the relationships between IL-3 and GM-CSF messenger (m) ribonucleic acid (RNA) expression in peripheral blood CD4+ cells and serum levels of eosinophil cationic protein (ECP), a marker of eosinophil activation, and disease activity in asthma.

METHODS

Venous blood was drawn from patients with acute severe asthma prior to the commencement of systemic steroid therapy (day 1) and 7 days afterwards (day 7), patients with stable disease and normal healthy volunteers. The capacity for expression of IL-3 and GM-CSF in ex vivo stimulated circulating CD4+ cells was assessed semi-quantitatively by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

We found that the capacity for expression of IL-3 and GM-CSF was significantly higher in acute asthmatics prior to steroid treatment (n = 24) than those in stable disease (n = 38) and healthy subjects (n = 32, P < 0.001 for IL-3 and < 0.05 for GM-CSF), but no difference was observed between the latter two groups. Further assessment made in 15 of the 24 acute asthmatics 7 days after systemic steroid treatment revealed a significant reduction in GM-CSF expression (P < 0.05) but not for IL-3. At the same time, PEF also improved significantly from 30.4 +/- 3.5% of predicted value to 72.9 +/- 7.2% (P < 0.0001) and serum ECP concentration also fell from 19.9 +/- 5.9 micrograms/L to 4.3 +/- 2.0 micrograms/L (n = 10, P < 0.01).

CONCLUSION

Our data suggest both IL-3 and GM-CSF may be important in the pathogenesis of acute severe asthma.

The delayed hypersensitivity response and host resistance in surgical patients. 20 years later

OBJECTIVE

A 20-year follow-up was conducted on research into the implications of a lack of a delayed-type hypersensitivity (DTH) skin test response among surgical patients.

SUMMARY BACKGROUND DATA

The authors' original report showed that a failed DTH response was associated with increased hospital mortality, but the role of specific and nonspecific host defense elements, comorbid factors, nutritional supplementation, and the mechanism for anergy in this adverse outcome was unknown.

METHODS

A data base of 4292 patients was analyzed and reported on individual studies designed to answer some of the above questions.

RESULTS

Prospective studies showed a strong association between the DTH response and mortality: reactive patients, 2.9% (75/2576); anergic patients, 20.9% (239/1142, chi square = 265, p < 0.0000001). Antibody response to protein antigens was reduced in anergic patients. Antibody response to polysaccharide antigens was normal in all patients. The hallmark of anergy is a lack of T cells in the skin, as measured by mRNA signal (CD3) for T cells. The nonspecific component of host defense, as measured by circulating and exudate polymorphonuclear cell function, showed no statistically significant difference between elective reactive and elective anergic patients. Notwithstanding some mild malnutrition in anergic patients, parental nutrition failed to correct the DTH response or many of the cellular immune functions measured.

CONCLUSIONS

Over the last 5 years, because of a reduction in overall patient mortality, the contribution of a reduced DTH response to septic related mortality has lost statistical significance in elective surgical patients. A reduced DTH response maintains its strong association to sepsis-related mortality in intensive care/trauma patients, and this is the group on which future research efforts should be concentrated.

The effect of disodium cromoglycate (DSCG) on in vitro proliferation of CD4+, CD8+, and CD19+ cell populations derived from allergic and healthy donors

The effect of disodium cromoglycate (DSCG) on in vitro proliferation of CD4+ and CD8+ T cells and CD19+ B cells, positively selected by immunomagnetic separation, was investigated. The cells were obtained from allergic patients with moderate serum IgE levels and mild to moderate atopic dermatitis, and healthy controls. The different cell subfractions were stimulated with mitogens or specific allergens, as well as cell supernatants from the lymphoblastoid B- (RPMI 8866) and T-hybridoma (166 A2) cell lines. Proliferative responses of T- and B-cell subsets stimulated with mitogens together with recombinant interleukin-2 (rIL-2) or accessory cells (AC) could be inhibited by DSCG. In allergic individuals, significant allergen-specific stimulation could be observed in the CD8-depleted peripheral blood mononuclear cell (PBMC) fractions. Isolated CD4+ T cells, without AC or IL-2, could also be stimulated with specific allergen, but the responses were rather low. DSCG inhibited, concentration dependently, all allergen-induced responses. Interestingly, only atopic derived CD4+ and CD8+ T cells were stimulated by soluble low-affinity IgE receptor (Fc epsilon RII/sCD23) and IgE binding factor (IgEBF), including IgE enhancing factor, present in culture supernatants from RPMI 8866 and 166 A2, respectively. These responses were also inhibited by DSCG. This was in contrast to the amplifying effect of DSCG on spontaneously proliferating RPMI 8866 and 166 A2 cells, cultured in fresh cRPMI 1640 medium without sCD23 and IgE enhancing factor. Our results show that DSCG delivers an inhibitory signal or signals to PBMC subpopulations expressing Fc epsilon RII/sCD23, either upregulated by phytohemagglutinin in normal and atopic cells, or by allergens or sCD23 in atopic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal splenic and thymic IL-4 and TNF-alpha expression in MRL-lpr/lpr mice

The MRL-lpr/lpr and MRL-(++) mice were studied for the expression of cytokines in the spleen, lymph node, thymus, kidney and brain through the reverse transcription-polymerase chain reaction (RT-PCR). The frequencies of IL-4 and TNF-alpha expression in the thymus and spleen were significantly higher in MRL-lpr/lpr mice than in MRL-(++) mice from the age of 17 to 32 weeks. More importantly, IL-4 transcript was demonstrated in the early rather than in the terminal stage of the lupus disease. At the 20th week, MRL-lpr/lpr mice with active disease exhibited higher concentrations of IL-1 alpha, IL-6 and TNF-alpha in serum than MRL-(++) mice. Interestingly, in MRL-lpr/lpr but not MRL-(++) mice, the IL-6 concentration in cultured supernatants of the thymic cells was significantly higher than that of the splenic or lymph node cells. On the other hand, IL-6 and IL-1 beta were expressed in the brain and kidney of MRL-lpr/lpr mice but not of MRL-(++) mice. Cultured MRL-lpr/lpr mesangial cells could also express IL-6 but to a lesser extent. These results suggest that the abnormal splenic and thymic IL-4 and TNF-alpha expression may predispose the development of autoimmune reactions. The expression of IL-1 beta and IL-6 in the brain and kidney may be implicated in the damage of these two organs in MRL-lpr/lpr mice.

Raised pro-inflammatory cytokines interleukin 6 and tumour necrosis factor alpha in coeliac disease mucosa detected by immunohistochemistry

The levels of two pro-inflammatory cytokines, interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha), in coeliac disease were studied by immunohistochemistry. Jejunal biopsy specimens from patients with untreated disease, (n = 11), treated disease (n = 9), and normal controls, (n = 11) were stained to detect IL-6, TNF-alpha, CD45 (pan-leukocyte), and CD68 (macrophage surface antigen). Positive cells were identified in the epithelium (per 100 enterocytes) and in the lamina propria (per unit area). There was a significant increase in median IL-6 and TNF-alpha staining in both the lamina propria and the epithelium of untreated coeliac disease patients (lamina propria, 16.2 and 13.0 respectively; epithelium, 0.86 and 1.21, all p < 0.05) when compared with treated coeliac disease patients (lamina propria; 6.0 and 6.2, epithelium; 0.60 and 0.60) and controls (lamina propria; 6.5 and 7.5, epithelium; 0.58 and 0.60). A significant increase in the number of CD45 positive cells was found in the untreated coeliac disease lamina propria and epithelium (p < 0.05) but this was accompanied by a significant rise in CD68 positive cells in the lamina propria only (p < 0.05). Increased IL-6 and TNF-alpha in the lamina propria and epithelium of patients with untreated coeliac disease further supports their role in the immune pathogenesis of this disorder.

CD4-positive cells from patients with IgA nephropathy demonstrate increased mRNA of cytokines that induce the IgA switch and differentiation

IgA nephropathy (IgAN) is characterized by raised serum IgA1 and mesangial IgA1 deposits. We have previously shown increased T-cell activation in IgAN. Recently, transforming growth factor-beta (TGF-beta) has been shown to induce IgA isotype switch at a clonal level and interleukin 5 (IL5) promotes differentiation into IgA-bearing B cells. In the present study we have examined the TGF-beta and IL5 mRNA expression by mitogen-activated CD4-positive T cells from patients with IgAN (n = 25), patients with other primary nephritides (CGN) (n = 24), and healthy control subjects (n = 25). The cytokine genes were analysed by reverse transcription (RT)-polymerase chain reaction (PCR) and were semi-quantitated by normalizing the differences occurring during RT and PCR using a housekeeping gene, beta-actin. CD4-positive T cells from IgA nephritic patients expressed a higher level of IL5 mRNA than healthy controls (P < 0.01) and patients with CGN (P < 0.005). CD4-positive T cells from IgA nephritic patients expressed a higher level of TGF-beta mRNA than healthy controls (P < 0.01) but no difference was demonstrated on comparison with CGN patients. Elevated TGF-beta mRNA expression in patients with CGN probably reflects its other important function as a 'sclerogenic' factor involved in the glomerulosclerosis found in these nephritides. Our data suggest that there is increased expression of cytokine genes which induce the IgA isotype switch and differentiation; these immunological abnormalities may be important in the pathogenesis of IgAN.

Increased mRNA encoding for transforming factor-beta in CD4+ cells from patients with IgA nephropathy

IgA nephropathy (IgAN) is a mesangial proliferative glomerulonephritis characterized by predominant mesangial IgA deposits. Recently, transforming growth factor-beta (TGF-beta) is shown to exert widespread effects on extracellular matrix by enhancing its accumulation. In an experimental model of acute mesangial glomerulonephritis TGF-beta appeared to be involved in the process of glomerulosclerosis, and treatment with antagonists of TGF-beta prevented the development of glomerulosclerosis. We examined the TGF-beta mRNA expression by mitogen activated CD4+ T cells from 31 patients with IgAN, 25 healthy controls and 10 patients with minimal change nephropathy (MCN) or focal glomerulonephritis (FGN) who were comparable in age and sex. The cytokine gene was analyzed with reverse transcription followed by polymerase chain reaction and was semiquantitated by normalizing the differences occurring during reverse transcription and polymerase chain reaction using a housekeeping gene, beta-actin. CD4+ T cells from IgA nephritic patients expressed a higher level of TGF-beta mRNA than that of healthy controls or that of MCN/FGN [TGF-beta/actin ratio 1.11 (median), range 0.24 to 3.87 vs. 0.88, range 0.2 to 3.83, P = 0.0157 and 0.36 range 0.09 to 1.6, P = 0.006]. When the biopsies were classified into three grades according to the severity of glomerular and interstitial pathology, there were highly significant differences between the TGF-beta mRNA in CD4+ T cells from the three groups of IgA nephritic patients (grade 1, 0.52, range 0.24 to 0.79; grade 2, 1.2, range 0.5 to 3.33; grade 3, 2.17, range 1.45 to 3.87].(ABSTRACT TRUNCATED AT 250 WORDS)

Increase of both circulating Th1 and Th2 T lymphocyte subsets in IgA nephropathy

IgA nephropathy (IgAN), characterized by glomerular deposition of IgA and frequently elevated plasma IgA levels, has increased T helper cell activity. In vitro measurement of cytokines in supernatant of cultured peripheral lymphocytes revealed conflicting findings. We examined the profile of cytokine mRNA expressed in purified CD4+ cells in patients with IgAN in order to study their pattern of Th1 (releases IL-2 and interferon-gamma (IFN-gamma)) and Th2 (releases IL-4 and IL-5) T cell response. We assessed the circulating CD4+ T cells in patients and normal controls by the expression of messenger RNA (mRNA) for IL-2, IL-4, IL-5 and IFN-gamma. The cytokine mRNAs were analysed with reverse transcription-polymerase chain reaction and were measured semiquantitatively by using a housekeeping gene, beta-actin. Compared with the control subjects, CD4+ T lymphocytes from patients with IgAN expressed a higher level of IL-2 mRNA (P = 0.007), IFN-gamma mRNA (P = 0.04), IL-4 mRNA (P = 0.048), and IL-5 mRNA (P = 0.016). Within these patients with IgAN, a good correlation was demonstrated between the gene expression of cytokines in Th1 or Th2 cells. The IL-2 mRNA levels in Th1 cells from these patients with IgAN also correlated significantly with the IL-4 or IL-5 mRNA levels in their Th2 cells. Our study revealed IgAN is associated with activation in circulating lymphocytes of the IL-2, IFN-gamma, IL-4 and IL-5 gene cluster, a pattern compatible with activation of both the Th1- and Th2-like T lymphocyte population. The increased transcription of these cytokines genes may be contributory to the immunopathologic findings in IgAN.

Cerebrospinal fluid interleukin-6, prostaglandin E2 and autoantibodies in patients with neuropsychiatric systemic lupus erythematosus and central nervous system infections

Cerebrospinal fluid (CSF) from patients with a variety of central nervous system (CNS) disorders was assayed for cytokines, prostaglandins, and autoantibodies. CSF interleukin-6 (IL-6) in patients with CNS infection (374.24 +/- 92.61 pg/mL) and neuropsychiatric systemic lupus erythematosus (NP-SLE) (71.40 +/- 5.89 pg/mL) were significantly higher than in patients with CNS inflammation (33.92 +/- 29.36 pg/mL) or controls (non-inflammatory CNS diseases) (4.35 +/- 3.00 pg/mL). Interleukin-1 beta, interferon alpha, and tumor necrosis factor alpha were undetectable in these samples: CSF prostaglandin E2 (PGE2) also exhibited similar patterns as IL-6. CSF immunoglobulin G (IgG) in patients with NP-SLE (8.84 +/- 1.80 mg/dL) was much higher than in patients with CNS infection (4.65 +/- 3.09 mg/dL), CNS inflammation (2.54 +/- 1.24 mg/dL), or controls (2.11 +/- 1.03 mg/dL). CSF autoantibodies against calf thymus antigens were present in patients with NP-SLE but not in patients with CNS infection as demonstrated by immunoblot. These results suggest that high IL-6 and PGE2 in CSF favors the diagnosis of CNS infection, while modestly elevated IL-6, high IgG, and autoantibodies against calf thymus antigens in CSF are the features of NP-SLE.