Downregulation of chemokine receptor 9 facilitates CD4+CD8αα+ intraepithelial lymphocyte development.

Intestinal intraepithelial lymphocytes (IELs) reside in the gut epithelial layer, where they help in maintaining intestinal homeostasis. Peripheral CD4+ T cells can develop into CD4+CD8αα+ IELs upon arrival at the gut epithelium via the lamina propria (LP). Although this specific differentiation of T cells is well established, the mechanisms preventing it from occurring in the LP remain unclear. Here, we show that chemokine receptor 9 (CCR9) expression is low in epithelial CD4+CD8αα+ IELs, but CCR9 deficiency results in CD4+CD8αα+ over-differentiation in both the epithelium and the LP. Single-cell RNA sequencing shows an enriched precursor cell cluster for CD4+CD8αα+ IELs in Ccr9-/- mice. CD4+ T cells isolated from the epithelium of Ccr9-/- mice also display increased expression of Cbfß2, and the genomic occupancy modification of Cbfß2 expression reveals its important function in CD4+CD8αα+ differentiation. These results implicate a link between CCR9 downregulation and Cbfb2 splicing upregulation to enhance CD4+CD8αα+ IEL differentiation.

Detection of CCL25 and the correlation between CCL25, CCL28, IL-7, and TSLP in human breast milk.

In this study, CCL25, a chemokine that contributes to the immunological function of the thymus and intestines, was detected in human breast milk (HBM) for the first time. We then focused on the correlations of CCL25 with CCL28, TSLP, and IL-7, which were predicted to interact with CCL25 in HBM. We also compared their levels between primiparous and multiparous women. A total of 53 parturient women were recruited. Their HBM was collected during 0-5 days and at 1 month after parturition and the CCL25, CCL28, IL-7, and TSLP levels in the HBM were analyzed using ELISA. The results showed that CCL25 and TSLP levels were significantly higher in colostrum than in mature milk. Moreover, CCL28 and IL-7 levels in colostrum showed a positive correlation. These results indicate that CCL28 and IL-7 in colostrum might interact positively with each other when produced in the mammary glands during lactation. The findings also suggest that the level of parity has no effect on their levels in HBM. In conclusion, our results clarify that CCL25 is present in HBM and that the concentrations of CCL25 and TSLP are higher in colostrum than in mature milk. Moreover, the production of CCL28 and IL-7 might be closely correlated in human colostrum.

Chemokine ligand 28 (CCL28) negatively regulates trabecular bone mass by suppressing osteoblast and osteoclast activities.

INTRODUCTION: Bone metabolism imbalances cause bone metabolism diseases, like osteoporosis, through aging. Although some chemokines are known to be involved in bone mass regulation, many have not been investigated. Thus, the present study aimed to investigate the role of chemokine ligand 28 (CCL28) on bone metabolism. MATERIALS AND METHODS: To investigate the role of CCL28 on bone metabolism, 10-week-old male wild-type and Ccl28 knockout (Ccl28 KO) mice were analyzed. Microcomputed tomography analysis and bone tissue morphometry were used to investigate the effect of Ccl28 deficiency on the bone. CCL28 localization in bone tissue was assumed by immunohistochemistry. Osteoblast and osteoclast markers were evaluated by enzyme-linked immunosorbent assay and quantitative reverse transcription-polymerase chain reaction. Finally, in vitro experiments using MC3T3-E1 and bone marrow macrophages revealed the direct effect of CCL28 on osteoblast and osteoclast. RESULTS: This study showed that Ccl28 deficiency significantly increased bone mass and the number of mature osteoblasts. Immunoreactivity for CCL28 was observed in osteoblasts and osteoclasts on bone tissue. Additionally, Ccl28 deficiency promoted osteoblast and osteoclast maturation. Moreover, CCL28 treatment decreased osteoblast and osteoclast activities but did not affect differentiation. CONCLUSION: In summary, this study indicated that CCL28 is one of the negative regulators of bone mass by suppressing osteoblast and osteoclast activities. These results provide important insights into bone immunology and the selection of new osteoporosis treatments.

Metastasis of Breast Cancer Promoted by Circadian Rhythm Disruption due to Light/Dark Shift and its Prevention by Dietary Quercetin in Mice.

Epidemiological studies have indicated that a disturbed circadian rhythm resulting from night-shift work is a potential risk factor for breast cancer. However, the mechanism of increased risk of breast cancer by night-shift work remains unclear, and there have been few in vivo studies conducted to definitively associate the two factors. In this study, BJMC3879Luc2 mouse breast cancer cells were transplanted into BALB/c mice. Mice were maintained under lighting conditions that modeled the two-shift system and were investigated for the effect of light/dark cycle disruption on tumor growth and lymph node metastasis. Circadian dysfunction, which was confirmed by measuring circadian locomotor activities using a nano tag device in our light/dark shift model, did not affect tumor growth. However, a significant increase in the number of lymph nodes with distant metastasis was observed. Neutrophil-to-lymphocyte ratio, which is an adverse prognostic factor of breast cancer and also indicator of inflammation, also increased. It has been demonstrated that a chronic inflammatory response is associated with cancer malignancy and poor prognosis in various cancers. These results suggest that night-shift work may also affect distant metastasis and prognosis. In addition, we investigated whether dietary quercetin has anti-metastatic activity against light/dark shift-induced metastasis. A diet containing 0.3 % quercetin significantly inhibited distant lymph node metastasis, particularly metastasis to the iliac and kidney lymph nodes. Our results contribute to our understandings of the effects of the external light environment on breast cancer metastasis and provide a glimpse into potential protective effects of dietary quercetin on light/dark disturbance-induced metastasis.

Age-related chemokine alterations affect IgA secretion and gut immunity in female mice.

The chemokines CCL25 and CCL28, which promote immune cell migration, are primarily expressed in the small and large intestines and play critical roles in sustaining gut immunity. In particular, these chemokines are closely related to intestinal IgA secretion. However, there is no research regarding the effects of aging on CCL25 and CCL28 expression and function. Therefore, in the present study, we investigated the effects of aging on production of CCL25 and CCL28, and on gut immunity, especially IgA secretion, using young and aged female mice. By aging, the levels of small intestinal mRNA and protein of CCL25 lowered, while these levels of CCL28 in colon became higher. Moreover, the number of IgA-antibody secreting cells (IgA-ASCs) and total IgA concentration decreased in the small intestine due to the age-associated reduction of CCL25. In contrast, colonic IgA production was increased due to up-regulation of CCL28, while the number of colonic IgA-ASCs was unchanged with aging. These results clearly demonstrate that aging-associated decrease in small intestinal CCL25 production and increase in colonic CCL28 production c be involved in aging-associated deterioration of gut immunity.

Catechins and Caffeine Promote Lipid Metabolism and Heat Production Through the Transformation of Differentiated 3T3-L1 Adipocytes from White to Beige Adipocytes.

To elucidate effects of catechins and caffeine on lipid metabolism in adipocytes and identify the mechanism of action, differentiated 3T3-L1 adipocytes were incubated in culture media containing catechins at 1, 2.5, 5, and 10 µg/mL and caffeine at 50 and 100 µg/mL, singly or in combination, for 8 days. Intracellular lipid accumulation and glycerol-3-phosphate dehydrogenase activity were strongly suppressed by catechins and caffeine combination treatment. The mRNA expression of PPARɤ, GLUT4, HSL, UCP-1, and TMEM26 were significantly increased in the combined groups. These findings suggest that the combined treatment inhibited lipid synthesis and improved lipid metabolism in adipocytes. Moreover, it was indicated that the differentiated 3T3-L1 adipocytes could be transformed from white adipocytes to beige-like adipocytes by catechins and caffeine, and accordingly that this transformation could promote calorigenic action. PRACTICAL APPLICATION: In this study, we revealed that the combined treatment of catechins and caffeine inhibited lipid synthesis and improved lipid metabolism in adipocytes. Moreover, the treatment may contribute to the transforming from white adipocytes to beige-like adipocytes, which could strongly promote calorigenic action.

Maternal prolactin during late pregnancy is important in generating nurturing behavior in the offspring.

Although maternal nurturing behavior is extremely important for the preservation of a species, our knowledge of the biological underpinnings of these behaviors is insufficient. Here we show that the degree of a mother's nurturing behavior is regulated by factors present during her own fetal development. We found that Cin85-deficient (Cin85-/-) mother mice had reduced pituitary hormone prolactin (PRL) secretion as a result of excessive dopamine signaling in the brain. Their offspring matured normally and produced their own pups; however, nurturing behaviors such as pup retrieval and nursing were strongly inhibited. Surprisingly, when WT embryos were transplanted into the fallopian tubes of Cin85-/- mice, they also exhibited inhibited nurturing behavior as adults. Conversely, when Cin85-/- embryos were transplanted into the fallopian tubes of WT mice, the resultant pups exhibited normal nurturing behaviors as adults. When PRL was administered to Cin85-/- mice during late pregnancy, a higher proportion of the resultant pups exhibited nurturing behaviors as adults. This correlates with our findings that neural circuitry associated with nurturing behaviors was less active in pups born to Cin85-/- mothers, but PRL administration to mothers restored neural activity to normal levels. These results suggest that the prenatal period is extremely important in determining the expression of nurturing behaviors in the subsequent generation, and that maternal PRL is one of the critical factors for expression. In conclusion, perinatally secreted maternal PRL affects the expression of nurturing behaviors not only in a mother, but also in her pups when they have reached adulthood.

Effects of catechins and caffeine on the development of atherosclerosis in mice.

Atherosclerosis is one of the diseases related to metabolic syndrome which is caused by obesity. Previous reports have shown that green tea and its components have anti-obesity effect. We examined whether catechins and caffeine can prevent the development of atherosclerosis by oral administration, singly or in combination to the atherosclerosis model mice. Results demonstrated that the number of atherosclerotic regions in the aorta was significantly reduced by the combined treatment, and the atherosclerotic area was also improved. Serum HDL-C increased by caffeine single treatment, but no effect on the TG and TC by any treatments. Moreover, ECG illuviated to atheromatous lesions in aorta and the illuviation was enhanced by caffeine. The mRNA expression levels of LOX-1 and TNF-α showed a tendency to suppress by the combined treatment. These results indicated that the combined administration of catechins and caffeine has the inhibitory effect on the development of atherosclerosis in mice.

Green Tea Extract-induced Acute Hepatotoxicity in Rats.

Although green tea is considered to be a healthy beverage, hepatotoxicity associated with the consumption of green tea extract has been reported. In the present study, we characterized the hepatotoxicity of green tea extract in rats and explored the responsible mechanism. Six-week-old IGS rats received a single intraperitoneal (ip) injection of 200 mg/kg green tea extract (THEA-FLAN 90S). At 8, 24, 48 and 72 hrs and 1 and 3 months after exposure, liver damage was assessed by using blood-chemistry, histopathology, and immunohistochemistry to detect cell death (TUNEL and caspase-3) and proliferative activity (PCNA). Analyses of malondialdehyde (MDA) in serum and the liver and of MDA and thymidine glycol (TG) by immunohistochemistry, as oxidative stress markers, were performed. Placental glutathione S-transferase (GST-P), which is a marker of hepatocarcinogenesis, was also immunohistochemically stained. To examine toxicity at older ages, 200 mg/kg green tea extract was administered to 18-wk-old female rats. In 6-wk-old rats, 12% of males and 50% of females died within 72 hrs. In 18-wk-old rats, 88% died within 72 hrs. The serum levels of aspartate aminotransferase, alanine aminotransferase and/or total bilirubin increased in both males and females. Single-cell necrosis with positive signs of TUNEL and caspase-3 was seen in perilobular hepatocytes from 8 hrs onward in all lobular areas. PCNA-positive hepatocytes increased at 48 hrs. MDA levels in the serum and liver tended to increase, and MDA- and TG-positive hepatocytes were seen immunohistochemically. GST-P-positive hepatocellular altered foci were detected in one female rat at the 3-month time point. In conclusion, a single injection of green tea extract induced acute and severe hepatotoxicity, which might be associated with lipid peroxidation and DNA oxidative stress in hepatocytes.

Green tea extract suppresses N-methyl-N-nitrosourea-induced photoreceptor apoptosis in Sprague-Dawley rats.

BACKGROUND: Retinitis pigmentosa (RP) is a group of inherited neurodegenerative human diseases characterized by the loss of photoreceptor cells by apoptosis and eventual blindness. A single intraperitoneal (ip) injection of N-methyl-N-nitrosourea (MNU) causes photoreceptor cell apoptosis within 7 days in rats. Green tea extract (THEA-FLAN 90S; GTE) is a common herbal supplement with pluripotent properties including antioxidant activity. The purpose of the present study was to evaluate the efficacy of GTE against photoreceptor apoptosis in 7-week-old female Sprague-Dawley rats that received a single ip injection of 40 mg/kg MNU. METHODS: The oral administration of 250 mg/kg/day GTE was initiated 3 days prior to MNU injection and continued once daily throughout the experiment. Rats were sacrificed at 12, 24, and 72 h and 7 days after MNU injection, and the eyes were examined morphologically and morphometrically. The photoreceptor cell ratio, retinal damage ratio, and retinal preservation ratio were used to determine the structural and functional alterations. The number of apoptotic photoreceptor cells per mm(2) was determined in situ by TdT-mediated dUTP-digoxigenin nick end labeling (TUNEL). Our results indicated that oral administration of GTE significantly suppressed the loss of photoreceptor cells morphometrically 7 days after MNU injection. The number of TUNEL-positive cells per mm(2) in MNU-exposed rat central retina with or without GTE administration was 981 vs. 2056 at 24 h after MNU injection. CONCLUSIONS: GTE structurally and functionally suppressed MNU-induced photoreceptor cell apoptosis. These findings indicate that GTE may help to ameliorate the onset and progression of human RP.

Regulation of telomere length by G-quadruplex telomere DNA- and TERRA-binding protein TLS/FUS.

Mammalian telomeres comprise noncoding TTAGGG repeats in double-stranded regions with a single-stranded TTAGGG repeat 3' overhang and are bound by a multiprotein complex with a telomeric repeat-containing RNA (TERRA) containing a UUAGGG repeat as a G-quadruplex noncoding RNA. TLS/FUS is a human telomere-binding protein that was first identified as an oncogenic fusion protein in human myxoid and round-cell liposarcoma. Here, we show that the Arg-Gly-Gly domain in the C-terminal region of TLS forms a ternary complex with human telomere G-quadruplex DNA and TERRA in vitro. Furthermore, TLS binds to G-quadruplex telomere DNA in double-stranded regions and to G-quadruplex TERRA, which regulates histone modifications of telomeres and telomere length in vivo. Our findings suggest that the G-quadruplex functions as a scaffold for the telomere-binding protein, TLS, to regulate telomere length by histone modifications.

Social isolation stress induces hepatic hypertrophy in C57BL/6J mice.

We previously reported that social isolation stimulated a stress response leading to increasing plasma corticosterone level and disruption of the hepatic lipid metabolism-related pathway, without changing body and organ weights, in mice after 4 weeks of social isolation stress, compared with the grouped-housing control (5 mice/cage). In this study, we evaluated the effects of social isolation stress for an extended period on physiologic changes in male C57BL/6J mice. Plasma corticosterone was reduced after 13 weeks, indicating mice might adapt to social isolation stress. However, body and visceral fat weights were significantly increased in combination with hepatic hypertrophy, and significant decreases in levels of triglyceride and adiponectin in plasma were observed. In conclusion, it is tempting to speculate that mice exposed to social isolation stress for 13 continuous weeks could be at an increased risk of overweight with hepatic hypertrophy. Our results also imply that physiological changes, at least fatty acid metabolism, under stress exposure might be an important factor when evaluating the chronic effects of environmental chemicals.

Catechins and Caffeine Inhibit Fat Accumulation in Mice through the Improvement of Hepatic Lipid Metabolism.

To elucidate the inhibiting mechanisms of fat accumulation by catechins, caffeine, and epigallocatechin gallate (EGCG), ICR mice were fed diets containing either 0.3% catechins or 0.1% EGCG and/or 0.05% caffeine for 4 weeks. After the feeding, intraperitoneal adipose tissues weights were significantly lower in the caffeine, catechins + caffeine, and EGCG + caffeine groups compared to controls. Hepatic fatty acid synthase (FAS) activity in the catechins + caffeine group was significantly lower, and the activities of acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase-II (CPT-II) were significantly higher, compared to the control group. However, these activities were not observed in the other groups. FAS mRNA expression levels in the catechins + caffeine group were significantly lower than in the control group. ACO and CPT-II mRNA levels were not different among all of the treatment groups. These findings indicate that the inhibitory effects of fat accumulation via a combination of catechins, EGCG, or caffeine were stronger collectively than by either catechins, EGCG, or caffeine alone. Moreover, it was demonstrated that the combination of catechins and caffeine induced inhibition of fat accumulation by suppression of fatty acid synthesis and upregulation of the enzymatic activities involved in ß-oxidation of fatty acid in the liver, but this result was not observed by combination of EGCG and caffeine.

Equine estrogen-induced mammary tumors in rats.

Long-term hormone replacement therapy is associated with an increased risk of breast, ovarian and endometrial cancers in women. Equine estrogens are a principal component of hormone replacement therapy; however, their tumorigenic potential toward mammary tissue and reproductive organs has not been extensively explored. A pellet containing equilin was inserted under the skin of female ACI rats and the development of mammary tumors was monitored. Histological examination revealed premalignant lesions such as apocrine metaplasia in whole-mount preparations of mammary gland from the equilin-treated rats. ACI rats given 10mg equilin developed palpable mammary tumors at 13 weeks of treatment, and 37.5% of the rats developed mammary tumors within 15 weeks. For 2.5mg equilin, palpable tumors were observed in 8.3% of the rats after 8 weeks' treatment; the frequency was lower than that (42.9%) observed with 2.5mg E(2). No tumors were observed in the untreated rats. Evidently, equilin is a mammary carcinogen, and this potential may be associated with development of breast and reproductive cancers in women receiving hormone replacement therapy.

Protection of brain and pancreas from high-fat diet: effects of catechin and caffeine.

To investigate the effect of a high-fat diet on brain and pancreas functions, we used SAMP10 mice that have characteristics of brain atrophy and cognitive dysfunction with aging. Simultaneously, we investigated the effect of green tea catechin consumption on high-fat diet feeding, because green tea catechin has been reported to improve brain atrophy, brain dysfunction and obesity. The body weight of mice fed a high-fat diet from 2 to 12 months was higher than that of the control, although the calorie intake was not. The high-fat diet also increased insulin secretion; however, the hypersecretion of insulin and obesity were suppressed when mice were fed a high-fat diet with green tea catechin and caffeine. Furthermore, brain atrophy was suppressed and the working memory, tested using Y-maze, improved in mice fed a high-fat diet containing green tea catechin and caffeine. The secretion of insulin might affect both obesity and brain function. A strong correlation was found between working memory and insulin release in mice fed a high-fat diet with green tea catechin and/or caffeine. The results indicate the protective effect of green tea catechin and caffeine on the functions of brain and pancreas in mice fed a high-fat diet.

Characterization of the estrogenic activities of zearalenone and zeranol in vivo and in vitro.

In the present study, we compared the estrogenic activity of zearalenone (ZEN) and zeranol (ZOL) by determining their relative receptor binding affinities for human ERalpha and ERbeta and also by determining their uterotropic activity in ovariectomized female mice. ZOL displayed a much higher binding affinity for human ERalpha and ERbeta than ZEN did. The IC(50) values of ZEN and ZOL for binding to human ERalpha were 240.4 and 21.79nM, respectively, and the IC(50) values for binding to ERbeta were 165.7 and 42.76nM, respectively. In ovariectomized female ICR mice, s.c. administration of ZEN at doses >or=2mg/kg/day for 3 consecutive days significantly increased uterine wet weight compared with the control group, and administration of ZOL increased the uterine wet weight at lower doses (>or=0.5mg/kg/day for 3 days). Based on available X-ray crystal structures of human ERalpha and ERbeta, we have also conducted molecular modeling studies to probe the binding characteristics of ZEN and ZOL for human ERalpha and ERbeta. Our data revealed that ZEN and ZOL were able to occupy the active site of the human ERalpha and ERbeta in a strikingly similar manner as 17beta-estradiol, such that the phenolic rings of ZEN and ZOL occupied the same receptor region as occupied by the A-ring of 17beta-estradiol. The primary reason that ZOL and ZEN is less potent than 17beta-estradiol is likely because 17beta-estradiol could bind to the receptor pocket without significantly changing its conformation, while ZOL or ZEN would require considerable conformational alterations upon binding to the estrogen receptors (ERs).

In vitro and in vivo estrogenic activity of chlorinated derivatives of bisphenol A.

The estrogenic activity of bisphenol A (BPA) and its chlorinated derivatives, 2-(3-chloro-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane (3-ClBPA) and 2,2-bis(3-chloro-4-hydroxyphenyl)propane (3,3'-diClBPA) was assessed by determining their relative binding affinity for the human estrogen receptor-alpha and -beta (ERalpha and ERbeta) and also their uterotrophic activity in ovariectomized female rats. BPA and its chlorinated derivatives were active in competing with [3H]17beta-estradiol for their binding to the human ERalpha and ERbeta proteins. While 3-ClBPA and 3,3'-diClBPA competed more effectively for ERalpha binding than BPA (IC50 values of 2.48x10(-5), 1.28x10(-5), and 1.08x10(-4)M, respectively), they had similar activity as BPA for competing the binding to ERbeta (IC50 values of 1.43x10(-5), 1.87x10(-5), and 2.59x10(-5)M, respectively). To determine the uterotropic activity, three doses (10, 50 and 100 mg/kg/day) of BPA and its derivatives were given to mature ovariectomized Sprague-Dawley rats for 3 consecutive days. Treatment of animals with 50 and 100 mg/kg/day of BPA or its chlorinated derivatives caused a significant increase in the uterine wet weight and the endometrial area. The results of our present study demonstrated that the affinities of 3-ClBPA and 3,3'-diClBPA for ERalpha were higher than the affinity of BPA, although the in vivo estrogenic activity of the two chlorinated BPAs in ovariectomized female Sprague-Dawley rats appeared to be comparable to that of BPA.

Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice.

To elucidate the anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, female ICR mice were fed on diets containing 2% green tea powder and diets containing 0.3% catechins, 0.05% caffeine and 0.03% theanine, which correspond, respectively, to their concentrations in a 2% green tea powder diet, singly and in combination for 16 weeks. Body weight and food intake were determined monthly during this period, kidneys, adrenals, liver, spleen, brain, pituitary and intraperitoneal adipose tissues (IPAT) were weighed and lipid levels in the serum and liver were measured at the end of this period. The body weight increase and weight of IPAT were significantly reduced by the diets containing green tea, caffeine, theanine, caffeine + catechins, caffeine + theanine and caffeine + catechins + theanine. Noticeably, the IPAT weight decreased by 76.8% in the caffeine + catechins compared to the control group. Serum concentrations of triglycerides (TG) and non-esterified fatty acids (NEFA) were decreased by green tea, catechins and theanine. Moreover, caffeine + catechins, caffeine + theanine and caffeine + catechins + theanine also decreased NEFA in the serum. The TG level in the liver was significantly reduced by catechins and catechins + theanine in comparison with the control. These results indicated that at least caffeine and theanine were responsible for the suppressive effect of green tea powder (GTP) on body weight increase and fat accumulation. Moreover, it was shown that catechins and caffeine were synergistic in anti-obesity activities.

Inhibitory effects of autoimmune disease by green tea in MRL-Faslprcg/Faslprcg mice.

To investigate whether green tea has inhibitory effects on the development of autoimmune disease (AID), one-month-old MRL-Faslprcg/Faslprcg mice were fed diets containing 2% green tea powder (GTP) for 3 months. At the end of GTP feeding, the weights of body, subcutaneous (s.c.) and intraperitoneal (i.p.) lymph nodes (LN), kidneys, spleen and intraperitoneal adipose tissue (IPAT), serological abnormalities and renal lesions were compared between GTP-fed and control mice. SCLN, IPLN, kidneys and IPAT weights in both sexes, spleen weight in males and body weight increase in males were significantly lower in GTP-fed mice. Particularly, LN hyperplasia and fatty accumulation were markedly reduced by GTP. Serum levels of anti-DNA antibodies and immune complexes (IC) were significantly lowered and proteinuria and blood urea nitrogen tended to be improved by GTP. The incidence of serious glomerulonephritis was significantly lower and nephric vasculitis was almost completely prevented in GTP-fed mice. Moreover, the survival of mice was significantly prolonged by GTP feeding for 6 months. These results indicate that the progression of lupus-like syndrome including glomerulonephritis was significantly delayed by reduced production of autoantibodies and IC in GTP-fed MRL-Faslprcg/Faslprcg mice, which led to the prolonged survival.

Significant role of Fas ligand-binding but defective Fas receptor (CD95) in lymph node hyperplasia composed of abnormal double-negative T cells.

The functional differences between two mutations of the Fas (CD95) locus, Faslpr (lpr) and Faslprcg (lprcg), were investigated using bone marrow (BM) transplantation on the C3H mouse background. Both lpr/lpr and lprcg/lprcg BM transferred caused lymph node (LN) hyperplasia in lpr/+ and lprcg/+ recipients, although it was clearly smaller than that in lpr/lpr and lprcg/lprcg recipients of lpr/lpr and lprcg/lprcg BM. In addition, both BM induced significantly larger LN hyperplasia in lprcg/+ than lpr/+ recipients. Appearance of CD4- CD8-[double negative (DN)] T cells in the periphery is the most consistent phenotype of Fas mutations. Importantly, the proportion of DN T cells was higher in larger LN hyperplasia in the order of lpr/+, lprcg/+ and lpr/lpr or lprcg/lprcg recipients. On the other hand, both lpr/lpr and lprcg/lprcg BM transferred into wild-type (+/+) mice caused marked LN atrophy. The former, but not the latter, induced wasting syndrome. Faslg1d (gld)-homozygous lpr/lpr BM transferred into +/+ mice elicited LN hyperplasia of the same extent as that in lpr/lpr mice transferred with lpr/lpr BM, but not wasting syndrome. Taken together with the fact that DN T cells massively express Fas ligand (FasL), this study implied that FasL overexpressed on DN cells may be involved in the accumulation of DN T cells in LN, LN atrophy and wasting syndrome, and that lprcg Fas, which can bind to Fas ligand but not transduce apoptosis signal into cells, may modulate these pathological conditions by interfering with the binding of FasL to Fas.