Autoantibodies to killer cell immunoglobulin-like receptor 3DL1 in patients with systemic lupus erythematosus.

A genetic variant of the killer immunoglobulin-like receptor 3DL1 (KIR3DL1) has been found in patients with systemic lupus erythematosus (SLE). Herein, we investigated the presence of autoantibodies to KIR3DL1 in a cohort of patients with SLE. We tested sera from 28 patients with SLE, 11 patients with rheumatoid arthritis (RA) and 17 healthy control subjects for anti-KIR3DL1 activity by an enzyme-linked immunosorbent assay (ELISA) using recombinant KIR3DL1-enhanced green fluorescent protein (EGFP) and EGFP proteins. Anti-KIR3DL1 antibodies were detected in 22 (79%) of the 28 patients with SLE, whereas they were present in only three (27%) of the 11 patients with RA examined. Notably, 10 (91%) of the 11 samples from patients with SLE prior to therapy had anti-KIR3DL1 antibodies. None of the samples from healthy donors were positive for the antibodies. Here, we report the presence of anti-KIR3DL1 antibodies in the sera of patients with SLE for the first time. Anti-KIR3DL1 autoantibodies may be involved in the pathogenesis of autoimmune diseases.

Impact of videogame play on the brain's microstructural properties: cross-sectional and longitudinal analyses.

Videogame play (VGP) has been associated with numerous preferred and non-preferred effects. However, the effects of VGP on the development of microstructural properties in children, particularly those associated with negative psychological consequences of VGP, have not been identified to date. The purpose of this study was to investigate this issue through cross-sectional and longitudinal prospective analyses. In the present study of humans, we used the diffusion tensor imaging mean diffusivity (MD) measurement to measure microstructural properties and examined cross-sectional correlations with the amount of VGP in 114 boys and 126 girls. We also assessed correlations between the amount of VGP and longitudinal changes in MD that developed after 3.0±0.3 (s.d.) years in 95 boys and 94 girls. After correcting for confounding factors, we found that the amount of VGP was associated with increased MD in the left middle, inferior and orbital frontal cortex; left pallidum; left putamen; left hippocampus; left caudate; right putamen; right insula; and thalamus in both cross-sectional and longitudinal analyses. Regardless of intelligence quotient type, higher MD in the areas of the left thalamus, left hippocampus, left putamen, left insula and left Heschl gyrus was associated with lower intelligence. We also confirmed an association between the amount of VGP and decreased verbal intelligence in both cross-sectional and longitudinal analyses. In conclusion, increased VGP is directly or indirectly associated with delayed development of the microstructure in extensive brain regions and verbal intelligence.

Comparison of the measuring efficacy of transepidermal water loss of a reasonably priced, portable closed-chamber system device H4500 with that of rather expensive, conventional devices such as Tewameter® and Vapometer®.

BACKGROUND/PURPOSE: Although measuring transepidermal water loss (TEWL) is important to assess the barrier function of the stratum corneum (SC), the commercially available instruments are rather expensive. Recently launched Model H4500 employs a closed-chamber system to measure TEWL and is more reasonably priced compared to devices currently in general use. METHODS: To check the reproducibility of the obtained data with H4500, we conducted measurements on the volar forearms of healthy volunteers and compared these data with those measured with Vapometer® and Tewameter® . Then, we checked the correlations between the TEWL data obtained with these different devices on the same volar forearms of 15 healthy volunteers before and after the artificial production of barrier damage of the SC by tape stripping or by 0.5% aqueous solution of sodium lauryl sulfate. RESULTS: The obtained intra-class correlation coefficient (ICC, [1, 1]) with 95% CI of H4500 was 0.927 (0.835-0.978). Namely, an excellent correlation could be found in the values of TEWL measured with these three different instruments not only on healthy skin but also on the artificially barrier-damaged skin. CONCLUSIONS: H4500 is considered to be practical for daily use because of its performance as well as its reasonable price as compared with conventional devices.

Visible light emission from a silica microbottle resonator by second- and third-harmonic generation.

We report the first observation of nonlinear harmonic generation and sum frequency generation (SFG) coupled with stimulated Raman scattering (SRS) via the second-order (χ(2)) and the third-order (χ(3)) nonlinearities in a silica microbottle resonator. The visible light emission due to third-harmonic generation (THG) was observed in both the output of a tapered fiber and the optical microscope images, which can be used to identify the axial mode profiles. SFG enabled by three- and four-wave mixing processes between the pump light and the light generated via SRS was also observed. Second-harmonic generation (SHG) and the SFG are enabled by χ(2) induced in silica by surface effects and multipole excitations.

Heart rate-corrected QT interval is a novel risk marker for the progression of albuminuria in people with Type 2 diabetes.

AIMS: A close association between heart rate-corrected QT interval (QTc) and albuminuria in people with Type 2 diabetes has been reported in cross sectional studies. The aim of this study was to evaluate the relationship between QTc and change in urine albumin excretion (UAE) or progression of albuminuria in people with Type 2 diabetes. METHODS: We measured QTc in 251 consecutive people at baseline. We performed a 5-year follow-up cohort study to assess the relationship between QTc and change in UAE, defined as an increase of UAE/follow-up duration (year), or progression of albuminuria, defined as an increase in the category of diabetic nephropathy. RESULTS: During follow-up, 23 of 151 people with normoalbuminuria and 13 of 73 people with microalbuminuria at baseline had progression of albuminuria. Multiple regression analysis demonstrated that QTc was independently associated with change in UAE (ß = 0.176, P = 0.0104). Logistic regression analyses showed that QTc was a risk marker for progression of albuminuria [odds ratio per 0.01-s increase in QTc 1.35, 95% confidence interval (CI) 1.11-1.66, P = 0.0024] after adjusting for confounders. According to the receiver operator characteristic (ROC) analysis, the optimal cut-off point of QTc for progression of albuminuria was 0.418 s [area under the ROC curve 0.75 (95% CI 0.66-0.82), sensitivity = 0.86, specificity = 0.56, P < 0.0001]. CONCLUSIONS: Heart rate-corrected QT interval could be a novel risk marker for progression of albuminuria in people with Type 2 diabetes.

Tumour characteristics, treatment patterns and survival of patients aged 80 years or older with colorectal cancer.

AIM: This study aimed to clarify tumour characteristics and treatment patterns for patients with colorectal cancer aged 80 years or older and the impact of age on survival using a large-scale cancer registry database. METHOD: The database was used to identify 40 851 colorectal cancer patients who underwent surgery between 1995 and 2004. Patients were stratified into four age groups (< 50, 50-64, 65-79, ≥ 80 years). Demographics, tumour characteristics, treatment pattern and survival were compared between age groups. Additionally, the impact of lymph node dissection and adjuvant chemotherapy on survival was studied using the propensity score-matching method. RESULTS: In the over 80 age group, patients were more commonly female, with right colon cancer, multiple primary cancers, history of colorectal cancer, high serum carcinoembryonic antigen values, large tumour, undifferentiated histology, and more frequent pT3/pT4 tumours. In contrast, metastatic disease, central lymph node dissection and adjuvant chemotherapy were less frequent. Overall survival and cancer-specific survival decreased with increasing age for any stage. Multivariate analysis showed age to be an independent predictor of overall survival (hazard ratio 1.45, 95% CI 1.34-1.58, P < 0.001). In the propensity score-matched cohort, overall survival of the patients with central node dissection and having adjuvant chemotherapy was significantly better than for those without. This difference was not statistically significant in patients aged 80 and above. CONCLUSION: This study showed a significant difference in tumour characteristics and treatment patterns in patients aged 80 and above. Even after adjustment for clinicopathological factors, the difference in survival persisted and age was considered a robust prognostic factor.

Human herpesvirus 6 reactivation on the 30th day after allogeneic hematopoietic stem cell transplantation can predict grade 2-4 acute graft-versus-host disease.

BACKGROUND: Viral infections and their occult reactivation occasionally cause not only organ damage, but also exacerbation of acute graft-versus-host disease (aGVHD), which may increase transplantation-related mortality synergistically. To determine correlations between viral reactivation and transplantation-related complications, we performed various viral screening tests on the 30th day after allogeneic hematopoietic stem cell transplantation (HSCT), and assessed the clinical implications. PATIENTS AND METHODS: Between August 2007 and January 2013, 49 patients (37 men, 12 women) underwent HSCT in our hospital. The stem cell sources were bone marrow (n = 21), peripheral blood (n = 13), and cord blood (n = 15). The presence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpesvirus (HHV) 6, and HHV7 in plasma samples prospectively collected from HSCT recipients on day 30 after HSCT was assayed by quantitative polymerase chain reaction, and the correlations with transplantation-related complications were evaluated. RESULTS: The positivities of CMV, EBV, HHV6, and HHV7 were 44.9%, 22.4%, 53.1%, and 18.3%, respectively. We analyzed transplantation-related complications, and a significant correlation was found only between HHV6 and grade 2-4 aGVHD from day 30 to day 100 (P < 0.001). Using a receiver operating characteristic curve, the area under the curve was calculated as 0.86 (95% confidence interval [CI], 0.74-0.98) between the viral load (VL) of HHV6 and grade 2-4 aGVHD. The sensitivity and specificity were 79% and 93%, respectively, when a cutoff value of 87 copies/mL was used. In multivariate analysis using the Fine and Gray proportional hazards model, the clinically determined high-risk patients (P = 0.004; hazard ratio [HR], 3.69; 95% CI, 1.52-9.00) and the positivity of HHV6 (P < 0.001; HR, 9.957; 95% CI, 2.68-37.06) were extracted as independent risk factors for the cumulative incidence of grade 2-4 aGVHD on or after post-HSCT day 30. The only risk factor extracted for the elevation of HHV6 VL >87 copies/mL was cord blood transplantation (P = 0.0032; odds ratio, 7.10; 95% CI, 1.98-30.00). CONCLUSION: All of the risk factors previously reported to predict severe aGVHD were obtained only during, but not after, HSCT. Our study suggests that the reactivation of HHV6 (≥ 87 copies/mL) at 30 days after HSCT is a possible predictive marker for grade 2-4 aGVHD on or after post-HSCT day 30.

Low serum potassium concentration is a predictor of chronic kidney disease.

AIMS: The aim of this study was to examine whether low serum potassium concentration could be a predictor of chronic kidney disease (CKD) in a community-based cohort. MATERIALS AND METHODS: We enrolled 1001 subjects, median period of 5.7 years, and evaluated the risk factors for CKD, defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2), and assessed whether low serum potassium concentration could predict CKD. RESULTS: Compared with the subjects without development of CKD, age, body mass index, fasting plasma glucose, uric acid (UA), creatinine and serum sodium concentration were higher, and serum potassium concentration was lower in subjects with development of CKD. Univariate Cox regression analyses demonstrated that age, body mass index, fasting plasma glucose, UA, creatinine, serum sodium concentration and serum potassium concentration were associated with progression of CKD. Multiple Cox regression analysis revealed that age, gender, creatinine and serum potassium concentration were independent predictors of CKD after adjustment for covariates. When serum potassium concentration was below 4.0 mmol/l at baseline, hazard ratio (95% confidence interval) of developing CKD was 2.65 (2.04-3.44; p < 0.0001). CONCLUSIONS: Serum potassium concentration could be a clinically relevant risk factor for the progression of CKD, defined as eGFR < 60 ml/min/1.73 m(2) , in healthy subjects.

Prospective study comparing the new sclerotherapy and hemorrhoidectomy in terms of therapeutic outcomes at 4 years after the treatment.

PURPOSE: Recently, sclerotherapy using a new sclerosing agent (aluminum potassium sulfate and tannic acid) has become widespread in Japan as a treatment for hemorrhoids. In the present study, we investigated whether sclerotherapy or surgical therapy (hemorrhoidectomy) is superior in terms of the therapeutic outcomes at 4 years. METHODS: We sent a questionnaire on symptoms and the degree of satisfaction to patients who underwent sclerotherapy or hemorrhoidectomy for grade 3 or 4 hemorrhoids in 2007, and compared the two therapies based on the responses, with respect to superiority of the therapeutic outcomes at 4 years. To identify the factors affecting the symptom-free and satisfaction rates, the univariate and multivariate analyses were performed for the following seven parameters: age, sex, degree of hemorrhoids, presence of external hemorrhoids, past history of treatment for hemorrhoids, number of hemorrhoids treated and the type of treatment. RESULTS: Overall, 75 % of the patients (195/260) responded to the questionnaire. In this study, the symptom-free rates were 53 % (30/57 patients) in the sclerotherapy group and 80 % (111/138 patients) in the hemorrhoidectomy group, and the satisfaction rates were 70 % (40/57 patients) in the sclerotherapy group and 88 % (121/138 patients) in the hemorrhoidectomy group. The results revealed that the type of treatment was the only factor affecting these two outcomes. CONCLUSIONS: Our results indicate that hemorrhoidectomy is superior to sclerotherapy. These findings may be useful in the treatment of hemorrhoid patients.

Distinct functional regions of the human polymeric immunoglobulin receptor.

The polymeric immunoglobulin receptor (pIgR) is a type I transmembrane protein that is expressed on the surfaces of glandular and intestinal epithelial cells. The extracellular portion of the pIgR is composed of six different domains. Domain 6 is involved in the enzymatic cleavage and release of the pIgR into the intestinal lumen as a free secretory component (fSC). A highly conserved 9-amino acid sequence is present in this region in various species. Although mutations in domain 6 are associated with particular diseases, such as IgA nephropathy and Epstein-Barr virus-related nasopharyngeal cancer, and the glutamic acid residues in the conserved 9-amino acid sequence are expected to be indispensable for the secretion of fSC, the importance of these residues has not been examined. In the present study, we attempted to examine the role of these residues in the enzymatic cleavage of the pIgR. The enzymatic cleavage of the pIgR was not affected by the presence of an alanine to valine substitution at position 580 or glutamine to alanine substitutions at positions 606 and/or 607, or the deletion of the whole 9-amino acid conserved sequence. Intriguingly, the 10 amino acid sequences flanking the N- and C-terminal ends of the conserved 9-amino acid sequence had opposite effects on pIgR cleavage. Namely, the N-terminal and C-terminal sequences enhanced and reduced pIgR cleavage efficiency, respectively. These results indicated that the pIgR can be divided into several functionally distinct regions.

Th17-cells in atopic dermatitis stimulate orthodontic root resorption.

OBJECTIVE: The aim of this study was to investigate how atopic dermatitis (AD) contributes to root resorption during orthodontic tooth movement. MATERIALS AND METHODS: Atopic dermatitis model mice and wild-type mice were subjected to an excessive orthodontic force (OF) to induce movement of the upper first molars. The expression levels of the tartrate-resistant acid phosphatase (TRAP), IL-17, IL-6, and RANKL proteins were determined in the periodontal ligament (PDL) by an immunohistochemical analysis. Furthermore, the effects of the compression force on co-cultures of CD4(+) cells from AD patients or healthy individuals and human PDL cells were investigated with regard to the levels of secretion and mRNA expression of IL-17, IL-6, RANKL, and osteoprotegerin. RESULTS: The immunoreactivities for TRAP, IL-17, IL-6, and RANKL in the AD group were found to be significantly increased. The double immunofluorescence analysis for IL-17/CD4 detected immunoreaction. The secretion of IL-17, IL-6, and RANKL, and the mRNA levels of IL-6 and RANKL in the AD patients were increased compared with those in healthy individuals. CONCLUSION: Th17 cells may therefore be associated with the deterioration of root resorption of AD mice, and may explain why AD patients are more susceptible to root resorption than healthy individuals when an excessive OF is applied.

Outcomes of case-matched injection sclerotherapy with a new agent for hemorrhoids in patients treated with or without blood thinners.

PURPOSE: In Japan, a new type of sclerotherapy termed ALTA (aluminum potassium sulfate and tannic acid) injection therapy has recently been introduced. The objectives of this study were to determine whether the presence or absence of antithrombotic treatment (AT) affected the efficacy rate or the occurrence of complications associated with ALTA injection sclerotherapy. METHODS: This study was a case-matched study of 37 patients who underwent ALTA therapy to treat hemorrhoids between 2007 and 2009. Each AT patient was matched for age and degree of hemorrhoids with a control non-AT patient. In each of the subgroups, the therapeutic efficacy of ALTA therapy was evaluated by comparing an assessment completed before therapy with an assessment completed 6 months after therapy. RESULTS: The efficacy in patients with bleeding did not differ between the two groups (P = 0.074). The efficacy in patients with prolapse was significantly lower in the AT group than in the non-AT group (P = 0.013). The two groups did not differ significantly in the occurrence of complications (P = 0.450). CONCLUSIONS: Among patients with hemorrhoids receiving AT, ALTA injection sclerotherapy is recommended for those in whom it is difficult to discontinue AT.

Upregulation of Polymeric Immunoglobulin Receptor Expression by the Heat-Inactivated Potential Probiotic Bifidobacterium bifidum OLB6378 in a Mouse Intestinal Explant Model.

We determined whether a potential probiotic bacterium, Bifidobacterium bifidum OLB6378 (BB6378), exerts beneficial effects on the mucosal immune system in a mouse intestinal explant model. The addition of heat-inactivated BB6378 to intestinal explants prepared from embryonic day 18 BALB/c mice increased the expression of polymeric immunoglobulin receptor (pIgR) mRNA by two- to fivefold. These effects were observed on ileal and colonic explants but not on jejunal explants, suggesting that the BB6378-induced pIgR upregulation is site-specific within the mouse intestine. The upregulation of pIgR protein expression in colonic explants was also detected after 24 h of culture. The results of DNA microarray analysis of ileal and colonic samples indicated that BB6378 increased the gene expression of interleukin (IL)-1α and IL-1ß, and IL-1α content in colonic explants was significantly increased after 20 h of culture with BB6378. We then examined the involvement of endogenously induced IL-1α in pIgR mRNA upregulation by using IL-1α knockout (KO) mice. Contrary to our expectations, pIgR mRNA expression was equally upregulated by BB6378 in colonic explants from BALB/c and IL-1α KO mice. Conversely, we examined the involvement of Toll-like receptors in pIgR mRNA upregulation by using MyD88 KO mice. The upregulation of pIgR was completely suppressed in the explants derived from MyD88 KO mice. Taken together, we conclude that in a mouse intestinal explant model, the heat-inactivated potential probiotic BB6378 increases intestinal pIgR expression in a site-specific manner and that the upregulation of pIgR could be explained by a direct microbial effect on the epithelium via Toll-like receptors.

Nuclear factor kappa B plays a pivotal role in polyinosinic-polycytidylic acid-induced expression of human ß-defensin 2 in intestinal epithelial cells.

Intestinal epithelial cells (IECs) play an important role in protecting the intestinal surface from invading pathogens by producing effector molecules. IECs are one of the major sources of human beta-defensin 2 (hBD-2), and can produce it in response to a variety of stimuli. Although IECs express Toll-like receptor 3 (TLR-3) and can respond to its ligand, double-stranded RNA (dsRNA), hBD-2 expression in response to dsRNA has not been elucidated. In the present study, using an artificial analogue of dsRNA, polyinosinic-polycytidylic acid (poly I:C), we investigated whether the human IEC line, HT-29, can produce hBD-2 in response to poly I:C. HT-29 cells can express hBD-2 mRNA only when stimulated with poly I:C. The induction of hBD-2 mRNA expression was observed at 3 h after stimulation and peaked at 12 h of post-stimulation. Pre-incubation of the cells with nuclear factor kappa B (NF-κB)-specific inhibitor, l-1-4'-tosylamino-phenylethyl-chloromethyl ketone (TPCK) and isohelenine abolished the expression of hBD-2. Detection of the poly I:C signal by TLR-3 on the surface of HT-29 cells was revealed by pre-incubating the cells with anti-TLR-3 antibody. The 5'-regulatory region of the hBD-2 gene contains two NF-κB binding sites. A luciferase assay revealed the importance of the proximal NF-κB binding site for poly I:C-induced expression of hBD-2. Among NF-κB subunits, p65 and p50 were activated by poly I:C stimulation and accumulated in the nucleus. Activation of the p65 subunit was investigated further by determining its phosphorylation status, which revealed that poly I:C stimulation resulted in prolonged phosphorylation of p65. These results indicate clearly that NF-κB plays an indispensable role in poly I:C induced hBD-2 expression in HT-29 cells.

Caspase 1-independent IL-1beta release and inflammation induced by the apoptosis inducer Fas ligand.

Fas ligand is a well-characterized apoptosis inducer. Here we demonstrate that Fas ligand induces the processing and secretion of interleukin-1beta (IL-1beta) in peritoneal exudate cells. This IL-1beta secretion is independent of IL-1beta converting enzyme (caspase 1), yet it is inhibited by caspase inhibitors, indicating that a caspase(s) in addition to IL-1beta converting enzyme can process IL-1beta. Inoculation of tumor cells expressing Fas ligand into wild-type mice induces a massive neutrophil infiltration that is, in contrast, suppressed in IL-1alpha/beta knockout mice. These results demonstrate a newly discovered role for Fas ligand in inflammation, and challenge the dogma that apoptosis does not induce inflammation.

IL-8 and MCP-1 induced by excessive orthodontic force mediates odontoclastogenesis in periodontal tissues.

OBJECTIVE: The aim of this study was to investigate how interleukin (IL)-8 (cytokine-induced neutrophil chemoattractant; CINC-1) and monocyte chemotactic protein (MCP)-1/CCL2 contribute to root resorption during orthodontic tooth movement. MATERIALS AND METHODS: Forty 6-week-old male Wistar rats were subjected to orthodontic force of 10 or 50 g to induce a mesially tipping movement of the upper first molars for 7 days. We determined the expressions of CINC-1, CXCR2, and MCP-1 proteins in root resorption area using immunohistochemistry. Furthermore, we investigated the effects of compression forces (CF) on IL-8 and MCP-1 production by human periodontal ligament (hPDL) cells. We observed an effect of chemokine treatment on rat odonto/osteoclasts in dentin slices that recapitulated root resorption. RESULTS: The immunoreactivity for CINC-1/CXCR2 and MCP-1 was detected in odontoclasts and PDL fibroblasts by the orthodontic force of 50 g on day 7. CF increased the secretion and the expression of mRNA of IL-8 and MCP-1 from PDL cells in a magnitude-dependent manner. Moreover, CINC-1 and MCP-1 stimulated osteoclastogenesis from rat osteoclast precursor cells. CONCLUSION: IL-8 (CINC-1) and MCP-1 may therefore facilitate the process of root resorption because of excessive orthodontic force.

CD8 T cell memory in B cell-deficient mice.

Antigen presentation by B cells and persistence of antigen-antibody complexes on follicular dendritic cells (FDC) have been implicated in sustaining T cell memory. In this study we have examined the role of B cells and antibody in the generation and maintenance of CD8+ cytotoxic T lymphocyte (CTL) memory. To address this issue we compared CTL responses to lymphocytic choriomeningitis virus (LCMV) in normal (+/+) versus B cell-deficient mice. The CTL response to acute LCMV infection can be broken down into three distinct phases: (a) the initial phase (days 3-8 after infection) of antigen-driven expansion of virus-specific CD8+ T cells and the development of effector CTL (i.e., direct ex vivo killers); (b) a phase of death (between days 10 and 30 after infection) during which >95% of the virus-specific CTL die and the direct effector activity subsides; and (c) the phase of long-term memory (after day 30) that is characterized by a stable pool of memory CTL that persist for the life span of the animal. The role of B cells in each of these three phases of the CTL response was analyzed. We found that B cells were not required for the expansion and activation of virus-specific CTL. The kinetics and magnitude of the effector CTL response, as measured by direct killing of infected targets by ex vivo isolated splenocytes, was identical in B cell-deficient and +/+ mice. Also, the expansion of CD8+ T cells was not affected by the absence of B cells and/or antibody; in both groups of mice there was an approximately 10,000-fold increase in the number of LCMV-specific CTL and a greater than 10-fold increase in the total number of activated (CD44hi) CD8+ T cells during the first week after virus infection. Although no differences were seen during the "expansion" phase, we found that the "death" phase was more pronounced in B cell-deficient mice. However, this increased cell death was not selective for LCMV-specific CTL, and during this period the total number of CD8+ T cells also dropped substantially more in B cell-deficient mice. As a result of this, the absolute numbers of LCMV-specific CTL were lower in B cell-deficient mice but the frequencies were comparable in both groups of mice. More significantly, the memory phase of the CTL response was not affected by the absence of B cells and a stable number of LCMV-specific CTL persisted in B cell-deficient mice for up to 6 mo. Upon reinfection, B cell-deficient mice that had resolved an acute LCMV infection were able to make accelerated CTL responses in vivo and eliminated virus more efficiently than naive B cell-deficient mice. Thus, CTL memory, as assessed by frequency of virus-specific CTL or protective immunity, does not decline in the absence of B cells. Taken together, these results show that neither B cells nor antigen-antibody complexes are essential for the maintenance of CD8+ CTL memory.

Autoimmune disease as a consequence of developmental abnormality of a T cell subpopulation.

Neonatal thymectomy (NTx), especially around day 3 after birth, causes various organ-specific autoimmune diseases in mice. This report shows that: (a) T cells expressing the interleukin 2 receptor alpha chains (CD25) ontogenically begin to appear in the normal periphery immediately after day 3, rapidly increasing within 2 wk to nearly adult levels (approximately 10% of CD3+ cells, especially of CD4+ cells); (b) NTx on day 3 eliminates CD25+ T cells from the periphery for several days; inoculation immediately after NTx of CD25+ splenic T cells from syngeneic non-Tx adult mice prevents autoimmune development, whereas inoculation of CD25- T cells even at a larger dose does not; and furthermore, (c) similar autoimmune diseases can be produced in adult athymic nu/nu mice by inoculating either spleen cell suspensions from 3-d-old euthymic nu/+ mice or CD25+ cell-depleted spleen cell suspensions from older, even 1-yr-old, nu/+ mice. The CD25- populations from neonates or adults are also similar in the profile of cytokine formation. These results, taken together, indicate that one aspect of peripheral self-tolerance is maintained by CD25+ T cells that sustain potentially pathogenic self-reactive T cells in a CD25- dormant state; the thymic production of the former is developmentally programmed to begin on day 3 after birth in mice. Thus, NTx on day 3 can, at least transiently, eliminate/reduce the autoimmune-preventive CD25+ T cells, thereby leading to activation of the self-reactive T cells that have been produced before NTx.

Development of chronic inflammatory arthropathy resembling rheumatoid arthritis in interleukin 1 receptor antagonist-deficient mice.

Interleukin (IL)-1 is a proinflammatory cytokine that plays important roles in inflammation, host defense, and the neuro-immuno-endocrine network. IL-1 receptor antagonist (ra) is an endogenous inhibitor of IL-1 and is supposed to regulate IL-1 activity. However, its pathophysiological roles in a body remain largely unknown. To elucidate the roles of IL-1ra, IL-1ra-deficient mice were produced by gene targeting, and pathology was analyzed on different genetic backgrounds. We found that all of the mice on a BALB/cA background, but not those on a C57BL/6J background, spontaneously developed chronic inflammatory polyarthropathy. Histopathology showed marked synovial and periarticular inflammation, with articular erosion caused by invasion of granulation tissues closely resembling that of rheumatoid arthritis in humans. Moreover, elevated levels of antibodies against immunoglobulins, type II collagen, and double-stranded DNA were detected in these mice, suggesting development of autoimmunity. Proinflammatory cytokines such as IL-1beta, IL-6, and tumor necrosis factor alpha were overexpressed in the joints, indicating regulatory roles of IL-1ra in the cytokine network. We thus show that IL-1ra gene deficiency causes autoimmunity and joint-specific inflammation and suggest that IL-1ra is important in maintaining homeostasis of the immune system. Possible involvement of IL-1ra gene deficiency in RA will be discussed.

Production of mice deficient in genes for interleukin (IL)-1alpha, IL-1beta, IL-1alpha/beta, and IL-1 receptor antagonist shows that IL-1beta is crucial in turpentine-induced fever development and glucocorticoid secretion.

Interleukin (IL)-1 is a major mediator of inflammation and exerts pleiotropic effects on the neuro-immuno-endocrine system. To elucidate pathophysiological roles of IL-1, we have first produced IL-1alpha/beta doubly deficient (KO) mice together with mice deficient in either the IL-1alpha, IL-1beta, or IL-1 receptor antagonist (IL-1ra) genes. These mice were born healthy, and their growth was normal except for IL-1ra KO mice, which showed growth retardation after weaning. Fever development upon injection with turpentine was suppressed in IL-1beta as well as IL-1alpha/beta KO mice, but not in IL-1alpha KO mice, whereas IL-1ra KO mice showed an elevated response. At this time, expression of IL-1beta mRNA in the diencephalon decreased 1.5-fold in IL-1alpha KO mice, whereas expression of IL-1alpha mRNA decreased >30-fold in IL-1beta KO mice, suggesting mutual induction between IL-1alpha and IL-1beta. This mutual induction was also suggested in peritoneal macrophages stimulated with lipopolysaccharide in vitro. In IL-1beta KO mice treated with turpentine, the induction of cyclooxygenase-2 (EC 1.14.99.1) in the diencephalon was suppressed, whereas it was enhanced in IL-1ra KO mice. We also found that glucocorticoid induction 8 h after turpentine treatment was suppressed in IL-1beta but not IL-1alpha KO mice. These observations suggest that IL-1beta but not IL-1alpha is crucial in febrile and neuro-immuno-endocrine responses, and that this is because IL-1alpha expression in the brain is dependent on IL-1beta. The importance of IL-1ra both in normal physiology and under stress is also suggested.