Facile, tunable, and SERS-enhanced HEPES gold nanostars

The facile, green synthesis of gold nanostars (AuNSs) with tunable branch lengths for SERS applications.

Enterococcus faecalis attenuates osteogenesis through activation of p38 and ERK1/2 pathways in MC3T3-E1 cells

AIM

To explore the role of Enterococcus faecalis in the proliferation, apoptosis and differentiation of osteoblasts.

METHODOLOGY

Pre-osteoblastic MC3T3-E1 cells were treated with heat-killed E. faecalis ATCC 29212 and clinical E. faecalis P25RC strains, respectively. Cell proliferation, mineralized calcium deposition, alkaline phosphatase (ALP) activity and apoptosis were assessed at various time-points. The expression levels of osteogenic-related genes including ALP, osteocalcin (OC), runt-related protein 2 (Runx2) and collagen type 1 (COL1) were also analysed throughout the duration of the experiment. Additionally, the involvement of mitogen-activated protein kinases (MAPKs) signalling pathways was analysed by Western blotting. In the presence of culture supernatant from E. faecalis-treated murine macrophages, apoptosis of MC3T3-E1 cells was detected with flow cytometry. Data were analysed using analysis of variance (anova), and P < 0.05 was considered significantly different.

RESULTS

E. faecalis significantly inhibited proliferation (P < 0.05) and also significantly induced apoptosis of MC3T3-E1 cells (P < 0.05), whilst differentiation seemed to be unaffected after 7 days of E. faecalis treatment. However, osteogenic differentiation was significantly inhibited with 21-day E. faecalis treatment (P < 0.05). The p38 and ERK1/2 phosphorylation pathways associated with mineral deposition and apoptosis were significantly activated in MC3T3-E1 cells. The culture supernatants from E. faecalis-treated macrophages induced osteoblast apoptosis.

CONCLUSIONS

E. faecalis exerted an inhibitory effect on osteogenesis in pre-osteoblastic MC3T3-E1 cells via phosphorylation of p38 and ERK1/2.

Current advances in the novel functions of hypoxia-inducible factor and prolyl hydroxylase in invertebrates

Oxygen is essential for aerobic life, and hypoxia has very severe consequences. Organisms need to overcome low oxygen levels to maintain biological functions during normal development and in disease states. The mechanism underlying the hypoxic response has been widely investigated in model animals such as Drosophila melanogaster and Caenorhabditis elegans. Hypoxia-inducible factor (HIF), a key gene product in the response to oxygen deprivation, is primarily regulated by prolyl hydroxylase domain enzymes (PHDs). However, recent findings have uncovered novel HIF-independent functions of PHDs. This review provides an overview of how invertebrates are able to sustain hypoxic damages, and highlights some recent discoveries in the regulation of cellular signalling by PHDs. Given that some core genes and major pathways are evolutionarily conserved, these research findings could provide insight into oxygen-sensitive signalling in mammals, and have biomedical implications for human diseases.

High-density interspecific genetic linkage mapping provides insights into genomic incompatibility between channel catfish and blue catfish

Catfish is the leading aquaculture species in the United States. The interspecific hybrid catfish produced by mating female channel catfish with male blue catfish outperform both of their parent species in a number of traits. However, mass production of the hybrids has been difficult because of reproductive isolation. Investigations of genome structure and organization of the hybrids provide insights into the genetic basis for maintenance of species divergence in the face of gene flow, thereby helping develop strategies for introgression and efficient production of the hybrids for aquaculture. In this study, we constructed a high-density genetic linkage map using the hybrid catfish system with the catfish 250K SNP array. A total of 26,238 SNPs were mapped to 29 linkage groups, with 12,776 unique marker positions. The linkage map spans approximately 3240 cM with an average intermarker distance of 0.25 cM. A fraction of markers (986 of 12,776) exhibited significant deviation from the expected Mendelian ratio of segregation, and they were clustered in major genomic blocks across 15 LGs, most notably LG9 and LG15. The distorted markers exhibited significant bias for maternal alleles among the backcross progenies, suggesting strong selection against the blue catfish alleles. The clustering of distorted markers within genomic blocks should lend insights into speciation as marked by incompatibilities between the two species. Such findings should also have profound implications for understanding the genomic evolution of closely related species as well as the introgression of hybrid production programs in aquaculture.

The effect of antifibrotic drug halofugine on Th17 cells in concanavalin A-induced liver fibrosis

Anti-inflammation strategy is one of the proposed therapeutic approaches to hepatic fibrosis. T helper (Th) 17 cells, which play a detrimental role in experimental murine models of inflammatory diseases, have been demonstrated to participate in the pathogenesis of liver damage. The inhibitory effect of halofuginone (HF), an active component of extracts derived from the plant alkaloid febrifugine, on collagen synthesis has been shown in animal models of the fibrotic disease. The aim of this study was to clarify the in vivo effect of HF on Th17 cells in concanavalin A-induced fibrosis rats. Haematoxylin-eosin (HE) staining and Masson staining were performed to observe collagen deposition. The presence of INF-gamma, TNF-alpha, IL-6, IL-17, IL-1beta, IL-33 and IL-10 in serum and the presence of ROR-γt, IL-17, TGF-β1 and α-SMA in liver tissue were detected. Flow cytometry was performed to analyse the percentage of Th17 cells. We observed significantly lower levels of INF-gamma, TNF-alpha, IL-6, IL-17, IL-1beta, TGF-β1 and α-SMA in HF-treated group of rats, and the percentage of Th17 cells in splenic lymphocyte was decreased well. Histological examination demonstrated that HF significantly reduced the severity of liver fibrosis in HF-treated rats. We concluded that HF (10 mg/kg) exerts an antifibrotic impact on Th17 cells and its relative cytokines in rats with ConA-induced fibrosis.

Efficient delivery of lentiviral vectors into resting human CD4 T cells

Resting human CD4 T cells are highly resistant to transfection or infection with lentiviral vectors derived from the human immunodeficiency virus. We now describe a flexible and efficient approach involving virus-like particles containing simian immunodeficiency virus lentiviral gene product protein X and pseudotyping with CXCR4-tropic HIV Env. This method permits effective genetic manipulation of these cells while preserving their naturally quiescent state. This technology can also be extended to primary lymphoid cultures where authentic cellular composition and functional relationships are preserved.

Bioinformatics analysis of Exonic Splicing Enhancers (ESEs) for predicting potential regulatory elements of hTERT mRNA splicing

OBJECTIVES

Alternative splicing of human telomerase reverse transcriptase (hTERT) has an important effect on regulating telomerase activity. Exonic splicing enhancers (ESEs) are a family of conserved splicing factors that participate in multiple steps of the splicing pathway. Our aim is to analyze the ESEs for predicting the potential regulatory elements of hTERT mRNA splicing.

MATERIALS AND METHODS

Enter the FASTA format of hTERT total sequences or individual exon as the input data in the main interface of ESEfinder3.0 and ESEfinder2.0 program. Analyze the data of output results and compare the differences between ESEfinder3.0 and ESEfinder2.0 program.

RESULTS

Five ESEs were predicted in exon 5 to exon 9 of hTERT. They were at position 108 located in hTERT exon 5, at position 92 located in exon 6, at position 22 located in exon 7, at position 73 located in exon 8 and at position 5 located in exon 9. There were no differences between ESEfinder 3.0 and ESEfinder 2.0 in our case.

CONCLUSIONS

The identification of these potential ESEs of hTERT might be helpful for the design of antisense oligonucleotides, which could modulate hTERT alternative splicing and inhibit telomerase activity.

Interleukin-2 and autoimmune disease occurrence and therapy

BACKGROUND

Interleukin-2(IL-2), also called T-cell growth factor and primarily produced by antigen-activated T cells, is a kind of lymphoid factor with immunoregulatory effect which can promote T-cell-dependent immune responses. IL-2 was first used as a therapeutic approach to boost immune responses in patients with invasive cancer or advanced HIV disease.

OBJECTIVES

The purpose of the review is to refer the mechanism of autoimmune disease caused by IL-2 deletion and the application of IL-2 in curing autoimmune disease.

STATE OF THE ART

IL-2 signal plays a key role in promoting the development, homeostasis and the function of the regulatory T cells. The deletion of IL-2 in vivo causes T cell-mediated autoimmune diseases. Now it is being considered as a kind of medicine inhibiting immune responses.

PERSPECTIVES

Further studies with controlled clinical trials will be needed to prove the potential of IL-2 as a therapeutic strategy for autoimmune diseases.

CONCLUSIONS

The decreased production of IL-2 in patients with autoimmune disease leads to immune defects, such as decreased production of Treg cells, decreased AICD and cytotoxicity. Combination therapy based on IL-2 may prove to be beneficial in curing the immunological disorders.

C-peptide reduces high-glucose-induced apoptosis of endothelial cells and decreases NAD(P)H-oxidase reactive oxygen species generation in human aortic endothelial cells

AIMS/HYPOTHESIS

Reactive oxygen species (ROS) generated during hyperglycaemia are implicated in the development of diabetic vascular complications. High glucose increases oxidative stress in endothelial cells and induces apoptosis. A major source of ROS in endothelial cells exposed to glucose is the NAD(P)H oxidase enzyme. Several studies demonstrated that C-peptide, the product of proinsulin cleavage within the pancreatic beta cells, displays anti-inflammatory effects in certain models of vascular dysfunction. However, the molecular mechanism underlying this effect is unclear. We hypothesised that C-peptide reduces glucose-induced ROS generation by decreasing NAD(P)H oxidase activation and prevents apoptosis

METHODS

Human aortic endothelial cells (HAEC) were exposed to 25 mmol/l glucose in the presence or absence of C-peptide and tested for protein quantity and activity of caspase-3 and other apoptosis markers by ELISA, TUNEL and immunoblotting. Intracellular ROS were measured by flow cytometry using the ROS sensitive dye chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (CM-H(2)-DCDFA). NAD(P)H oxidase activation was assayed by lucigenin. Membrane and cytoplasmic levels of the NAD(P)H subunit ras-related C3 botulinum toxin substrate 1 (rho family, small GTP binding protein Rac1) (RAC-1) and its GTPase activity were studied by immunoblotting and ELISA. RAC-1 (also known as RAC1) gene expression was investigated by quantitative real-time PCR.

RESULTS

C-peptide significantly decreased caspase-3 levels and activity and upregulated production of the anti-apoptotic factor B cell CLL/lymphoma 2 (BCL-2). Glucose-induced ROS production was quenched by C-peptide and this was associated with a decreased NAD(P)H oxidase activity and reduced RAC-1 membrane production and GTPase activity.

CONCLUSIONS/INTERPRETATION

In glucose-exposed endothelial cells, C-peptide acts as an endogenous antioxidant molecule by reducing RAC-1 translocation to membrane and NAD(P)H oxidase activation. By preventing oxidative stress, C-peptide protects endothelial cells from glucose-induced apoptosis.

Transport through the maxillary ostium in the ethmoid infundibulum

OBJECTIVE

The aim of this study was to use transnasal endoscopy to observe transport through the maxillary ostia in the ethmoid infundibulum, to gain more basic scientific information about the nasal cavity and paranasal sinus.

METHODS

Transnasal observation of 512 patients in a supine or seated position was conducted with 0- and 70-degree nasal endoscopes. Drainage pathways of mucopurulence at the natural maxillary ostia were observed. A dye test was also performed in 53 patients to clearly observe real-time transport of activated carbon in the ethmoid infundibulum.

RESULTS

Among 914 ethmoid infundibula, mucopurulence and activated carbon were transported out of 31 and 53 natural maxillary ostia, respectively. All ethmoid infundibula drained at the inferior edges of the ostium, despite patients' supine or seated positions. Fourteen cases of mucopurulence and 17 cases of activated carbon flowed circularly in the ethmoid infundibula. The flow of activated carbon from the natural ostium to the nasopharynx could also be observed simultaneously or solely. However, there were 6 ostia through which no activated carbon flowed back into or drained out of the sinus, despite flow from the natural ostium to the nasopharynx or circular flow.

CONCLUSIONS

The drainage pathway of the maxillary ostium is its inferior edge. The accessory ostium is only necessary to promote circular flow. Mucopurulence or activated carbon, which flowed circularly in the ethmoid infundibulum, can also be gradually transported to the nasopharynx. Revision surgery may not be necessary for all patients with circular chronic maxillary sinuses.

Reactant-governing growth direction of indium nitride nanowires

Hexagonal wurtzite InN nanowires are grown via a vapor-liquid-solid (VLS) mechanism with an Au catalyst. Microstructure characterizations of a large number of nanowires demonstrate that the growth direction of InN nanowires is governed by variable NH(3) flux. InN nanowires at a NH(3) flux of 10 standard cubic centimeters per minute (sccm) grow preferentially in a hexagonal close-packed (hcp) <1010> direction, while those at 100 sccm NH(3) flux favor the hcp <0001> direction. A free energy minimization model is proposed to interpret this phenomenon. The first-principles calculations reveal that the <1010> oriented nucleus has the lowest energy at the lower NH(3) flux. In contrast, when NH(3) flux is high, the <0001> oriented nucleus has the lowest energy.

C-peptide is internalised in human endothelial and vascular smooth muscle cells via early endosomes

AIMS/HYPOTHESIS

There is increasing evidence that C-peptide exerts intracellular effects in a variety of cells and could be beneficial in patients with type 1 diabetes. Exactly how C-peptide achieves these effects, however, is unknown. Recent reports showed that C-peptide internalised in the cytoplasm of HEK-293 and Swiss 3T3 cells, where it was not degraded for at least 1 h after uptake. In this study, we investigated the hypothesis that C-peptide is internalised via an endocytic pathway and traffics to classic endocytic organelles, such as endosomes and lysosomes.

METHODS

We studied the internalisation of C-peptide in vascular endothelial and smooth muscle cells, two relevant targets of C-peptide activity, by using Alexa Fluor-labelled C-peptide probes in living cells and immunohistochemistry employing confocal laser-scanning microscopy. To examine trafficking to subcellular compartments, we used fluorescent constructs tagged to RAB5A, member RAS oncogene family (RAB5A) to identify early endosomes, or to lysosomal-associated membrane protein 1 (LAMP1) to identify lysosomes.

RESULTS

C-peptide internalised in the cytoplasm of cells within punctate structures identified as early endosomes. Internalisation was clearly detectable after 10 min of incubation and was blocked at 4 degrees C as well as with excess of unlabelled C-peptide. A minor fraction of vesicles, which increased with culture time, co-localised with lysosomes. Uptake of C-peptide was reduced by monodansylcadaverine, a pharmacological compound that blocks clathrin-mediated endocytosis, and by nocodazole, which disrupts microtubule assembly.

CONCLUSIONS/INTERPRETATION

C-peptide internalises in the cytoplasm of cells by endocytosis, as demonstrated by its localisation in early endosomes. Endosomes might represent a signalling station, through which C-peptide might achieve its cellular effects.

A meta-analysis on the association of HER-2 overexpression with prognosis in human osteosarcoma

Various studies examining the relationship between HER-2 overexpression and clinical outcome in patients with osteosarcoma have yielded inconclusive results. The purpose of the current study was to evaluate the relation of HER-2 status with clinical outcome in osteosarcoma. We conducted a meta-analysis of five studies that evaluated the relation between HER-2 status and 2-year survival. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on 2-year survival. The combined relative risk in patients with osteosarcoma for 2-year survival was 1.26 (95% confidence interval, 0.50-3.14; P = 0.63). HER-2-positive status tended to be associated with a worse 2-year survival, but the overall results were not formally statistically significant. An unfavourable prognostic effect of HER-2 overexpression in osteosarcoma was evident from the meta-analysis. However, because several studies were excluded by the current eligibility criteria, caution is needed in interpreting the results.

Differential expression of human telomerase reverse transcriptase β-site remaining alternative splicing variants (hTERT β+ ASV) in gastric carcinogenesis

e15641

Background: To investigate the changes of hTERT alternative splicing variants pattern in gastric cancer, precancerous lesions and normal gastric mucosa tissue. Methods: Three alternative splicing sites (α, β, γ) were selected and designed PCR primer. The expression of 8 hTERT alternative splicing variants (ASVs) in gastric cancer, precancerous lesions and normal gastric mucosa were detected by Semi-nested RT-PCR. The expression of β-site remaining ASV (β+ASV) in specimens of gastric cancer and specimens of precancerous lesions was detected by SYBER Green real-time PCR. Telomerase enzyme activity was evaluated associated with the different hTERT ASVs. Results: The positive rate of active full-length (α+β+γ+ ) ASV was significantly higher in gastric cancer than in precancerous lesions and normal mucosa (94.7% vs. 40.0% and 0, P<0.05). The positive rates of other ASVs were not different among the 3 groups(P>0.05). The positive rates of β+ ASVs (including α+β+γ+ASV, α-deletion ASV, γ-deletion ASV, αγ-deletion ASV) were 11.1% in normal mucosa,40.0% in precancerous lesions and 94.7% in gastric cancer (P<0.05). SYBR Green real-time RT-PCR showed that the expression level of β+ASV was 6.99 times higher in gastric cancer than in precancerous lesions. Further, increased telomerase enzyme activity was only associated with expression of the full-length hTERT isoform. Conclusions: hTERT alternative splicing pattern is different during gastric carcinogenesis. β+ASV was widely expressed in gastric carcinogenesis and may provide some information for diagnosis of gastric cancer or precancerous lesions. The gene expression patterns of hTERT alternative splicing variants may provide some useful information for diagnosis of gastric cancer and precancerous lesions.

No significant financial relationships to disclose.

Patients with inflammatory bowel disease may have a transforming growth factor-beta-, interleukin (IL)-2- or IL-10-deficient state induced by intrinsic neutralizing antibodies

Ulcerative colitis (UC) and Crohn's disease (CD) are considered to be immunologically mediated disorders that share certain features with murine models of colitis. Whether any of these models are physiologically relevant to the human condition remains controversial. The hypothesis is that increased amounts of antibodies neutralizing transforming growth factor (TGF)-beta, interleukin (IL)-2 or IL-10 create a relative immunodeficient state in inflammatory bowel disease (IBD) that predisposes to disease. To evaluate this, serum samples from patients with UC or CD and from normal healthy individuals were studied by enzyme-linked immunosorbent assays. Antibodies recognizing TGF-beta were most prevalent in UC (P<0.01); anti-IL-10 antibodies were elevated in CD (P<0.05), while anti-IL-2 antibodies were the same for all three groups. Importantly, the percentage of IBD patients with at least one of the antibody levels greater than any control value was 30% for UC and 33% for CD. To verify the presence of these antibodies, immobilized TGF-beta was exposed to UC sera and the attached proteins identified by Western blot assay. The proteins proved to be exclusively immunoglobulin (Ig) G. To evaluate the neutralizing activity of these antibodies, cytokine-specific IgG from subjects in each group of patients was incubated with TGF-beta, IL-2 or IL-10 before addition to a bioassay with changes in viability determined by a colorimetric analysis. Antibodies from most individuals in all three groups neutralized the action of each cytokine. This study shows that about one-third of IBD patients may have a relative deficiency of TGF-beta, IL-2 or IL-10 due to an increase in neutralizing antibodies in their sera.

SELDI-TOF MS proteinchip technology for screening of serum markers of HBV-induced hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is highest among primary liver cancer. HBV and HBV-induced liver cirrhosis may lead to HCC (1). At present, it is difficult to diagnose HCC at early stage or to differentiate HCC. Therefore, it is much needed to explore and develop a simple, rapid diagnostic method, which has higher sensitivity and specificity for HCC at early stage (2, 3). Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) is a novel non-electrophoresis-based proteomic technology. SELDI offers the advantages of rapid and simple examination as well as high specificity and sensitivity (4, 5). To our knowledge,there has been little study reported using SELDI-TOF-MS technology to investigate HCC. In this study, 25 cases of HCC patients not receiving any therapy, 25 cases receiving the interposition chemotherapy and 50 cases of the healthy people were tested by Weak cationic exchange (WCX2) protein chip and SELDI-TOF-MS. The differentially expressed peptides or proteins were analyzed by BioMarker Wizard software. At the different M/Z value range, seven peptides/ proteins were obviously different among these three groups. Four peptides including 6489.48Da, 6662.34Da, 8593.75Da and 8720.23Da were up-regulated in healthy controls, two including 7777.27Da and 9250.00Da were up-regulated in the patients with HCC without receiving any therapy and one protein of 16200.17Da was up-regulated in the patients with HCC receiving the interposition chemotherapy. Using Biomarker Pattern software, one pattern including two peptides (7777.27Da, 9250.00Da) can separate HCC without receiving any therapy from normal controls. This diagnosis pattern gave the much-improved sensitivity of 92% and the specificity of 100%. Through searching protein database, these seven peptides or proteins were identified as possible Galanin related peptide, Pro-neuregulin-4 protein, small inducible cytokine A15 precursor, 9 kDa protein, CSL-zincfinger protein 1, mitochondrial hinge protein, actin related protein, respectively. Using SELDI-TOF MS, the method of sieving the tumor markers from HCC becomes quick and valid. These differentially expressed peptides or proteins could be biomarkers of HCC in the serum and drug targets for treating HCC.

Chaotic Dynamics in Tracing BAEP and its Application on Investigating Brainstem Malfunction

The purpose of this study is to investigate the chaotic dynamics of tracing (dynamic) brainstem auditory evoked potential (BAEP), then to investigate the brainstem malfunction via dynamic characteristics of tracing BAEP. The radial basis function neural network (RBFNN) technique in combination with the moving window average (MWA) method was employed in order to extract the tracing BAEP from strong noise background. Data of noisy BAEP were collected from the Infantile spasm (IS) group with brainstem malfunction and the tester group respectively. The chaotic dynamics of tracing BAEP were analyzed using phase projection and correlation dimension techniques. The results of this study have demonstrated: (1) there is a much stronger determination in BAEP than in noisy BAEP shown by more deterministic phase projections and lower D<inf>2</inf>in BAEP; (2) trajectories of BAEP never repeat and the value of correlation dimension is fractal; (3) the phase projection of BAEP for brainstem malfunction group shows more chaotic and has higher D<inf>2</inf>than those for the tester group. The conclusions of this investigation suggest that BAEP is chaotic not deterministic and there is rich dynamics in BAEP; tracing BAEP is much more useful than noisy BAEP in describing brainstem malfunction because BAEP shows determination corresponding to brainstem function; BAEP in brainstem malfunction has more non-order dynamics than that in the tester.

Investigation of hydroxamic acids as laccase-mediators for pulp bleaching

A number of hydroxamic acids have been synthesized and investigated as laccase-mediators for pulp bleaching. As compared with N-hydroxyacetanilide (NHA), one of the most effective laccase-mediators reported so far, N-(4-cyanophenyl)acetohydroxamic acid (NCPA), resulted in the highest brightness and lowest kappa number of hardwood kraft pulp of all the laccase-mediators studied. The bleaching efficacy of a laccase/7-cyano-4-hydroxy-2H-1,4-benzoxazin-3-one system was also comparable with that of a laccase/NHA system. A laccase/NCPA system was further studied for the bleaching of unbleached softwood kraft pulp. The effects of pulp consistency, laccase dosage, NCPA dosage, incubation time, and oxygen pressure on the bleaching efficacy of a laccase/NCPA system were studied.

Degradation of non-phenolic lignin by the white-rot fungus Pycnoporus cinnabarinus

High-molecular-weight lignin was methylated with diazomethane. The lignin (i.e., phenolic lignin) and methylated lignin (i.e., non-phenolic lignin) were mixed with fully bleached softwood pulp. Degradation of the lignin preparations by the white rot fungus Pycnoporus cinnabarinus was studied. After a 3-month incubation with the fungus, over 40% of the non-phenolic lignin and about 70% the phenolic lignin were degraded. The presence of phenolic hydroxyl groups in lignin greatly enhanced the degradation rate of lignin. This study reveals that P. cinnabarinus, an exclusively laccase-producing fungus, is capable of oxidatively degrading both phenolic and non-phenolic lignins. The ability of the fungus to degrade non-phenolic lignin suggests that a laccase/mediator system is involved in the complete degradation of lignin. After the fungal degradation of lignins, the content of carboxylic acids substantially increased for both phenolic and non-phenolic lignins.

Cellular immune response against tropomyosin isoform 5 in ulcerative colitis

We have reported an autoantibody response in ulcerative colitis (UC) against human tropomyosin isoform 5 (hTM5), the predominant colonic epithelial cell hTM isoform. In this report, we determined the number of IFN-gamma-secreting cells (spot-forming cells, SFC) against hTM5 by an enzyme-linked immunospot (ELISPOT) assay. Another cytoskeletal protein, caldesmon, CaD40, was used as a control antigen. Peripheral blood mononuclear cells were separated by a Ficoll density gradient from 28 patients with UC, 13 patients with Crohn's disease (CD), and 9 healthy subjects (HS). The mean (+/-SEM) SFC values against hTM5 in UC, CD, and HS were 48.8 +/- 8.1, 18.6 +/- 4.6, and 20.8 +/- 8.6, respectively. The value in UC was significantly higher than those in CD (P < 0.005) and HS (P < 0.025). SFC values in CD did not differ from those in HS. None of the 50 samples (except 1 UC) reacted to the CaD40 antigen. This study demonstrates, for the first time, a defined colon epithelial cell antigen, hTM5, that is capable of inducing a significant T cell response in UC but not in CD.