Oxygenation index (OI=mean airway pressure MAP × FiO2 × 100÷PaO2) is used to assess severity of hypoxic respiratory failure (HRF) and persistent pulmonary hypertension of the newborn (PPHN). An indwelling arterial line or arterial punctures are necessary to obtain PaO2 for calculation of OI. Oxygenation can be continuously and non-invasively assessed using pulse oximetry. The use of oxygen saturation index (OSI=MAP × FiO2 × 100÷SpO2) can be an alternate method of assessing severity of HRF.
To evaluate the correlation between OSI and OI in (a) neonates with HRF and (b) a lamb model of meconium aspiration syndrome.
Human neonates: A retrospective chart review of 74 ventilated late preterm/term neonates with indwelling arterial access and SpO2 values in the first 24 hours of life was conducted. OSI and OI were calculated and correlated.
Lambs: Arterial blood gases were drawn and preductal SpO2 was documented in 40 term newborn lambs with asphyxia and meconium aspiration. OI and OSI were calculated and correlated with pulmonary vascular resistance (PVR).
Mean values of OSI & OI showed a correlation coefficient of 0.952 in neonates (mean value of 308 observations in 74 neonates) and 0.948 in lambs (mean value of 743 observations in 40 lambs). In lambs, with increasing PVR, there was a decrease in OI and OSI.
OSI correlates significantly with OI in infants with HRF. This noninvasive measure may be used to assess severity of HRF and PPHN in neonates without arterial access.
oxygenation index; pulmonary vascular resistance; pulmonary hypertension
DNA vaccination can generate both humoral and cellular immunity, resulting in potential prophylactic and therapeutic vaccines in variety of conditions, including hepatitis B virus (HBV) infection. Fusion of cytokine gene is one of the ways to increase the immunogenicity of DNA vaccine. Interleukin (IL)-21 has been demonstrated to play an immunomodulatory role in HBV infection. Thus, we aimed to investigate the ability of IL-21 in the regulation of middle version of HBV envelop protein (MS) DNA vaccine. Fusion plasmid encoding IL-21 linked with MS was constructed. Normal and HBV transgenic mice were immunized by plasmid. pcDNA-IL-21/S2S induced a comparable level of anti-HBs antibody and HBsAg-specific CD8+ T-cell response with pcDNA-S2S. Furthermore, the level of circulating HBsAg was decreased by induction of anti-HBs antibody and HBsAg-specific CD8+ T-cell response to both pcDNA-IL-21/S2S and pcDNA-S2S vaccination in HBV transgenic mice. Thus, immunization with DNA vaccine encoding HBV MS protein induced both T- and B-cell response by targeting the specific antigen. Furthermore, it was also revealed that MS DNA vaccination could break immune tolerance in HBV transgenic mice. But IL-21 did not strengthen immune response induced by HBV DNA immunization. Our study suggested that MS-expressing plasmid may be useful for both preventive and therapeutic methods in HBV infection. However, IL-21 does not improve the immunogenicity and efficacy of MS DNA vaccination, and thus may not be used as a therapeutic marker for chronic hepatitis B.
ASXL1 is the obligate regulatory subunit of a deubiquitinase complex whose catalytic subunit is BAP1. Heterozygous mutations of ASXL1 that result in premature truncations are frequent in myeloid leukemias and Bohring–Opitz syndrome. Here we demonstrate that ASXL1 truncations confer enhanced activity on the ASXL1–BAP1 complex. Stable expression of truncated, hyperactive ASXL1–BAP1 complexes in a haematopoietic precursor cell line results in global erasure of H2AK119Ub, striking depletion of H3K27me3, selective upregulation of a subset of genes whose promoters are marked by both H2AK119Ub and H3K4me3, and spontaneous differentiation to the mast cell lineage. These outcomes require the catalytic activity of BAP1, indicating that they are downstream consequences of H2AK119Ub erasure. In bone marrow precursors, expression of truncated ASXL1–BAP1 complex cooperates with TET2 loss-of-function to increase differentiation to the myeloid lineage in vivo. Our data raise the possibility that ASXL1 truncation mutations confer gain-of-function on the ASXL–BAP1 complex.
Premature truncations of ASXL1, a subunit of a deubiquitinase complex, are frequent in myeloid leukemia. Here, the authors show that expression of truncated ASXL1 in a haematopoietic precursor cell line enhances the deubiquitinase activity and leads to differentiation to the mast cell lineage.
Dysregulation of ribosome biogenesis causes human diseases, such as Diamond-Blackfan anemia, del (5q-) syndrome and bone marrow failure. However, the mechanisms of blood disorders in these diseases remain elusive. Through genetic mapping, molecular cloning and mechanism characterization of the zebrafish mutant cas002, we reveal a novel connection between ribosomal dysfunction and excessive autophagy in the regulation of hematopoietic stem/progenitor cells (HSPCs). cas002 carries a recessive lethal mutation in kri1l gene that encodes an essential component of rRNA small subunit processome. We show that Kri1l is required for normal ribosome biogenesis, expansion of definitive HSPCs and subsequent lineage differentiation. Through live imaging and biochemical studies, we find that loss of Kri1l causes the accumulation of misfolded proteins and excessive PERK activation-dependent autophagy in HSPCs. Blocking autophagy but not inhibiting apoptosis by Bcl2 overexpression can fully rescue hematopoietic defects, but not the lethality of kri1lcas002 embryos. Treatment with autophagy inhibitors (3-MA and Baf A1) or PERK inhibitor (GSK2656157), or knockdown of beclin1 or perk can markedly restore HSPC proliferation and definitive hematopoietic cell differentiation. These results may provide leads for effective therapeutics that benefit patients with anemia or bone marrow failure caused by ribosome disorders.
Hematopoietic stem cells; zebrafish; kri1l; ribosome biogenesis; autophagy; PERK; misfolded/unfolded protein
Toxoplasma gondii; shortness of breath and fever; compound sulfamethoxazole; clindamycin phosphate
Purpose: Innate and adaptive immune responses play vital roles in initiating and maintaining the immunological homeostasis in both physiological and pathological processes. However, the expression and function of the important cells and molecules as well as their interaction in hepatitis B virus (HBV) infection has not been well elucidated. The aim of the current study was to determine the pattern of Toll-like receptor 2 (TLR2) in T cells in HBV infection and the function of TLR2 in regulation of T helper 17 (Th17) cells response. Methods: Thirty-four patients with HBV infection (ten acute and twenty-four chronic) were enrolled. HBV-specific and -nonspecific Th17 cells and TLR2 expression in T cells were analyzed by flow cytometry. The function of TLR2 agonist for induction of IL-17 production was also determined. Results: HBV-specific and -nonspecific IL-17 secretion in CD4+ (Th17 cells) and CD8+ T cells was significantly elevated in chronic HBV infection. Viral-specific TLR2 expression in CD4+, CD8+, and Th17 cells was also remarkably increased in patients with chronic hepatitis B. Moreover, TLR2 agonist Pam3Csk4 directly activated Th17 cells response without antigen stimulation in HBV infection. Conclusion: TLR2, which traditionally associated with innate immunity, might also promote Th17 cells response in HBV infection. The function of TLRs in regulation of adaptive immune response in HBV infection, which might play an important role in persistent HBV infection.
Hepatitis B virus; Toll-like receptor; T helper 17 cells; immunoregulation
Neuroglobin (Ngb) is well known as a physiological role in oxygen homeostasis of neurons and perhaps a protective role against hypoxia and oxidative stress. In this study, we found that Ngb is expressed in rat heart tissues and it is related to isoproterenol induced cardiac hypertrophy. Moreover, overexpression or knock-down of Ngb influences the expression of hypertrophic markers ANP and BNP and the ratio of hypertrophic cells in rat H9c2 myoblasts when isoproterenol treatment. The Annexin V-FITC/PI Staining, Western blot and qPCR analysis showed that the involvement in p53-mediated apoptosis of cardiomyocytes of Ngb is might be the mechanism. This protein could prevent the cells against ROS and POS-induced apoptosis not only in nervous systems but also in cardiomyocytes. From the results, it is concluded that Ngb is a promising protectant in the cardiac hypertrophy, it may be a candidate target to cardiac hypertrophy for clinic treatment.
Apoptosis; p53; oxidative stress; cardiac hypertrophy; cardiomyocytes
Irritable bowel syndrome (IBS) has significant mental and physical comorbidities. However, little is known about the day-to-day burden these comorbidities place on quality of life (QOL), physical and mental function, distress, and symptoms of patients.
We collected cross sectional data from 175 patients with IBS, diagnosed based on Rome III criteria (median age, 41 y; 78% women), referred to 2 specialty care clinics. Patients completed psychiatric interviews, a physical comorbidity checklist, the IBS symptom severity scale, the IBS quality of life instrument, the brief symptom inventory, the abdominal pain intensity scale, and the SF-12 health survey.
Patients with IBS reported an average of 5 comorbidities (1 mental, 4 physical). Subjects with more comorbidities reported worse QOL after adjusting for confounding variables. Multiple linear regression analyses indicated that comorbidity type was more consistently and strongly associated with illness burden indicators than disease counts. Of 10, 296 possible physical–mental comorbidity pairs, 6 of the 10 most frequent dyads involved specific conditions (generalized anxiety, depression, back pain, agoraphobia, tension headache, insomnia). These combinations were consistently associated with greater illness and symptom burdens (QOL, mental and physical function, distress, more severe symptoms of IBS, pain).
Comorbidities are common among patients with IBS. They are associated with distress and reduced QOL. Specific comorbidities are associated with more severe symptoms of IBS.
Chronic disease; health related quality of life; comorbidity; transdiagnostic; stress; IBSQOL
Immune cells and molecules play a vital role in initiating, maintaining, regulating immunological homeostasis and inflammation in many pathological and physiological processes; however, the changes on expressions and functions of these cells and molecules in hepatitis B virus (HBV) infection have not been elucidated well.
The current study aimed to determine the expression pattern of different cytokines, chemokines, immune cells in HBV infection and their association with disease progression.
Patients and Methods:
Sixty-nine patients with chronic HBV infection were enrolled. Five immune cell subsets and 46 cytokines and chemokines were analyzed by flow cytometry and Luminex 200.
In comparison to healthy individuals and asymptomatic HBV carriers, expression of CXCL9, CXCL10, CXCL11, and IL-10 were elevated in patients with chronic active HBV and had positive correlation with ALT levels. In contrast, G-CSF, MCP-3, and IFN-γ levels were significantly decreased in patients with chronic active HBV infection in contrast to carriers and healthy individuals; however, these down regulations did not show any correlation with either virological findings or liver inflammation. Although the proportion of CD4+ CD25 high regulatory T cells (Tregs) was higher in patients with HBV infection than in healthy controls, no correlations were found between Tregs and other cytokines or chemokines.
CXCR3-associated chemokines might contribute to liver inflammation in chronic hepatitis B, while MCP-3 and G-CSF were inhibited by HBV infection. Host immune response was suppressed as manifested by an increase in CD4+ CD25high Tregs and IL-10 as well as a decrease in IFN-γ. Exploiting the expression pattern of cytokine and chemokine may help to develop a better understanding of chronic HBV infection pathogenesis.
Hepatitis B Virus; Cytokines; Chemokines; Immunomodulation
The aim of the present study was to observe the effect of varying the timing of surgery on the fracture healing process and the expression levels of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2 in rats. A total of 192 rats underwent closed femur fracture modelling. The rats underwent open reduction and internal fixation surgery 1, 3, 5, 7, 11 and 14 days subsequent to the fracture occurring. Immunohistochemical staining and analysis of the VEGF and BMP-2 expression levels were simultaneously conducted on bone from the fracture site of the rats on various days. The VEGF and BMP-2 expression levels at the fracture sites were higher and were maintained for a longer period of time in the 7- and 11-day surgery groups than in the other surgery groups and the rats that did not undergo surgery. The 5-day surgery group demonstrated a greater intensity in BMP-2 expression compared with the remaining surgery groups; however, no significant differences were identified between 1-day surgery and non surgery groups. In the 3-day surgery group, the expression levels VEGF and BMP-2 were low at each stage of the fracture-healing process and were lower compared with those observed in the non-surgery group. The timing of the surgical procedures affected the VEGF and BMP-2 expression levels at the fracture sites of the experimental rats and, the optimal time for performing surgery was identified to be within the first two weeks. However, surgery may not be conducive to fracture healing if it is performed within the first few days following fracture.
fracture healing; vascular endothelial growth factor; bone morphogenetic protein-2; surgery timing
A long-standing but poorly understood defect in autoimmune diseases is dysfunction of the hematopoietic cells. Leukopenia is often associated with systemic lupus erythematous (SLE) and other autoimmune diseases. In addition, homeostatic proliferation of T cells, which is a host response to T cell lymphopenia, has been implicated as potential cause of rheumatoid arthritis (RA) in human and experimental models of autoimmune diabetes in the NOD mice and the BB rats. Conversely, successful treatments of aplastic anemia by immune suppression suggest that the hematologic abnormality may have a root in autoimmune diseases. Traditionally, the link between autoimmune diseases and defects in hematopoietic cells has been viewed from the prism of antibody-mediated hemolytic cytopenia. While autoimmune destruction may well be part of pathogenesis of defects in hematopoietic system, it is worth considering the hypothesis that either leukopenia or pancytopenia may also result directly from defective hematopoietic stem cells (HSC). We have recently tested this hypothesis in the autoimmune Scurfy mice which has mutation Foxp3, the master regulator of regulatory T cells. Our data demonstrated that due to hyperactivation of mTOR, the HSC in the Scurfy mice are extremely poor in hematopoiesis. Moreover, rapamycin, an mTOR inhibitor rescued HSC defects and prolonged survival of the Scurfy mice. Our data raised the intriguing possibility that targeting mTOR dysregulation in the HSC may help to break the vicious cycle between cytopenia and autoimmune diseases.
Cytopenia; homeostatic proliferation; CD24; mTOR; hematopoietic stem cells; autoimmune diseases; inflammatory cytokines; rapamycin
Mammalian Sin1 plays key roles in the regulation of mitogen activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling. Sin1 is an essential component of mTOR complex (mTORC) 2. The function of Sin1 and mTORC2 remains largely unknown in T cells. Here we investigate Sin1 function in T cells using mice which lack Sin1 in the hematopoietic system. Sin1 deficiency blocks the mTORC2 dependent Akt phosphorylation in T cells during development and activation. Sin1 deficient T cells exhibit normal thymic cellularity and percentages of double negative, double positive and single positive CD4 and CD8 thymocytes. Sin1 deficiency does not impair T cell receptor (TCR) induced growth and proliferation, and normal CD4+ helper cell differentiation. However Sin1 deficiency results in an increased proportion of Foxp3+ natural T regulatory (nTreg) cells in the thymus. We show that the TGF-β dependent differentiation of CD4+ T cells in vitro is enhanced by the inhibition of mTOR but not loss of Sin1 function. Our results reveal that Sin1 and mTORC2 are dispensable for the development and activation of T cells but play a role in natural Treg cell differentiation.
Depression is a type of complex psychiatric disorder with long-term, recurrent bouts, and its etiology remains largely unknown. Here, an integrated approach utilizing 1H NMR and UPLC-Q-TOF/MS together was firstly used for a comprehensive urinary metabonomics study on chronic unpredictable mild stress (CUMS) treated rats. More than twenty-nine metabolic pathways were disturbed after CUMS treatment and thirty-six potential biomarkers were identified by using two complementary analytical technologies. Among the identified biomarkers, nineteen (10, 11,
16, 17, 21–25, and 27–36) were firstly reported as potential biomarkers of CUMS-induced depression. Obviously, this paper presented a comprehensive map of the metabolic pathways perturbed by CUMS and expanded on the multitude of potential biomarkers that have been previously reported in the CUMS model. Four metabolic pathways, including valine, leucine and isoleucine biosynthesis; phenylalanine, tyrosine and tryptophan biosynthesis; tryptophan metabolism; synthesis and degradation of ketone bodies had the deepest influence in the pathophysiologic process of depression. Fifteen potential biomarkers (1–2, 4–6, 15, 18, 20–23, 27, 32, 35–36) involved in the above four metabolic pathways might become the screening criteria in clinical diagnosis and predict the development of depression. Moreover, the results of Western blot analysis of aromatic L-amino acid decarboxylase (DDC) and indoleamine 2, 3-dioxygenase (IDO) in the hippocampus of CUMS-treated rats indicated that depletion of 5-HT and tryptophan, production of 5-MT and altered expression of DDC and IDO together played a key role in the initiation and progression of depression. In addition, none of the potential biomarkers were detected by NMR and LC-MS simultaneously which indicated the complementary of the two kinds of detection technologies. Therefore, the integration of 1H NMR and UPLC-Q-TOF/MS in metabonomics study provided an approach to identify the comprehensive potential depression-related biomarkers and helpful in further understanding the underlying molecular mechanisms of depression through the disturbance of metabolic pathways.
This study proposed a new strategy for uncovering the active chemical constituents of a traditional Chinese medicines (TCMs) formula, Chaihu-Shu-Gan-San (CSGS). Metabonomics and chemical profile were integrated in combination with the multivariate statistical analysis (MVA) to discover the chemical constituents which contribute to the antidepressant effect of CSGS. Based upon the difference between CSGS and QZ (CSGS without Zhi-Qiao) extracts in the chemical profiles and the regulations of metabolic disturbances induced by CUMS, synephrine, naringin, hesperidin, and neohesperidin were recognized as the active constituents of CSGS from Zhi-qiao responsible for those missing regulations of CSGS when Zhi-Qiao was subtracted from the whole formula. They participated in the regulations of the deviated metabolites 2–4, 10–14, and 22–25, involved in metabolic pathways of ketone bodies synthesis, phenylalanine, tyrosine and tryptophan biosynthesis, valine, aspartate, glutamate metabolism, and glycolysis/gluconeogenesis. Furthermore, the assay of MAO-A activity confirmed the potential antidepressant effect of naringin and its active sites on the MAO-A was inferred by molecular docking study. The integration of metabonomics and chemical profile was proved to be a useful strategy for uncovering what the active chemical constituents in TCM formula are and how they make contributions for the efficacy of the formula.
BACKGROUND & AIMS
T-helper (Th)17 cells that secrete interleukin (IL)-22 have immunomodulatory and protective properties in the liver and other tissues. IL-22 induces expression of proinflammatory genes, but is also mitogenic and anti-apoptotic in hepatocytes.
Therefore, it could have multiple functions in the immune response to hepatitis B virus (HBV).
We examined the role of IL-22 in regulating liver inflammation in HBV transgenic mice and measured levels of IL-22 in HBV-infected patients.
In HBV transgenic mice, injection of a single dose of IL-22 increased hepatic expression of proinflammatory genes, but did not directly inhibit virus replication. When splenocytes from HBV-immunized mice were transferred into HBV transgenic mice, the severity of the subsequent liver damage was ameliorated by neutralization of IL-22. In this model, IL-22 depletion did not affect interferon-γ–mediated noncytopathic inhibition of virus replication initiated by HBV-specific cytotoxic T cells, but it significantly inhibited recruitment of antigen–non-specific inflammatory cells into the liver. In patients with acute HBV infections, the percentage of Th17 cells in peripheral blood and concentration of IL-22 in serum were significantly increased.
IL-22 appears to be an important mediator of the inflammatory response following recognition of HBV by T cells in the liver. These findings might be relevant to the development of cytokine-based therapies for patients with HBV infection.
liver disease; immune response; mouse model; anti-viral
Mitogen-activated protein kinases (MAPKs) are key mediators of the T cell receptor (TCR) signals but their roles in T helper (Th) cell differentiation are unclear. Here we showed that the MAPK kinase kinases MEKK2 (encoded by Map3k2) and MEKK3 (encoded by Map3k3), negatively regulated transforming growth factor-β (TGF-β)-mediated Th cell differentiation. Map3k2-/-Map3k3Lck-Cre/- mice showed an abnormal accumulation of regulatory T (Treg) and Th17 cells in the periphery, consistent with Map3k2-/-Map3k3Lck-Cre/- naïve CD4+ T cells' differentiation into Treg and Th17 cells with a higher frequency than wild-type (WT) cells after TGF-β stimulation in vitro. In addition, Map3k2-/-Map3k3Lck-Cre/- mice developed more severe experimental autoimmune encephalomyelitis. Map3k2-/-Map3k3Lck-Cre/- T cells exhibited impaired phosphorylation of the SMAD2 and SMAD3 proteins at their linker regions, which negatively regulated the TGF-β responses in T cells. Thus, the crosstalk between TCR-induced MAPK and the TGF-β signaling pathways is important in regulating Th cell differentiation.
The effect of oxygen concentration on lowering pulmonary vascular resistance (PVR) during resuscitation in a model of persistent pulmonary hypertension of the newborn (PPHN) is not known. PPHN was induced in fetal lambs by ductal ligation 9 d prior to delivery. Following delivery by cesarean section, resuscitation of PPHN lambs with 21%, 50%, or 100% O2 (n=6 each) for 30min produced similar decreases in PVR. Lambs were then ventilated with 50% O2 for 60min and exposed to inhaled NO (iNO-20ppm). Initial resuscitation with 100% O2 significantly impaired the subsequent response to iNO compared to 21% O2 (42±9 vs. 22±4% decrease from baseline PVR). Finally, each lamb was randomly and sequentially ventilated with 10%, 21%, 50%, or 100% O2. PVR decreased with increased concentrations of inhaled O2 up to 50%, there being no additional decrease in PVR with 100% O2. When PVR was correlated with PaO2, the maximal change in PVR was achieved at PaO2 values < 60 mmHg. We conclude that resuscitation with 100% O2 does not enhance pulmonary vasodilation compared to 21% and 50% O2, but impairs the subsequent response to iNO in PPHN lambs. Hypoxia increases PVR but hyperoxia does not confer significant additional pulmonary vasodilation in lambs with PPHN.
T cell homeostasis is crucial for maintaining an efficient and balanced T cell immunity. The interaction between TCR and self peptide (sp) MHC ligands is known to be the key driving force in this process, and it is believed to be functionally and mechanistically different from that initiated by the antigenic TCR stimulation. Yet, very little is known about the downstream signaling events triggered by this TCR-spMHC interaction and how they differ from those triggered by antigenic TCR stimulation. In this study, we show that T cell conditional ablation of MEKK3, a Ser/Thr kinase in the MAPK cascade, causes a significant reduction in peripheral T cell numbers in the conditional knockout mice, but does not perturb thymic T cell development and maturation. Using an adoptive mixed transfer method, we show that MEKK3-deficient T cells are severely impaired in lymphopenia-induced cell proliferation and survival. Interestingly, the Ag-induced T cell proliferation proceeds normally in the absence of MEKK3. Finally, we found that the activity of ERK1/2, but not p38 MAPK, was attenuated during the lymphopenia-driven response in MEKK3-deficient T cells. Together, these data suggest that MEKK3 may play a crucial selective role for spMHC-mediated T cell homeostasis.
Summary:The program Fluctuation AnaLysis CalculatOR (FALCOR) is a web tool designed for use with Luria–Delbrück fluctuation analysis to calculate the frequency and rate from various mutation assays in bacteria and yeast. Three calculation methods are available through this program: (i) Ma-Sandri-Sarkar Maximum Likelihood Estimator (MSS-MLE) method, (ii) Lea-Coulson method of the median (LC) and (iii) frequency.
Availability: The FALCOR rate calculator is currently accessible at http://www.mitochondria.org/protocols/FALCOR.html. This program is written as a Java™ Applet, requiring a web browser enabled with Sun MicroSystems' Java Virtual Machine.
Retinoids have been used for years as monotherapy and/or in combination for treatment and suppression of cutaneous malignancies in patients with basal cell nevus syndrome, xeroderma pigmentosum, or cutaneous T-cell lymphoma (CTCL) basal cell carcinoma (BCC). We report 4 cases with BCC confirmed by histopathology who were treated by short-term systemic acitretin combined with retinoic acid 0.1% cream. The 4 cases with BCC showed good response to the treatment without severe adverse effects during treatment and follow-up. The finding suggests that acitretin may be an appropriate treatment option for elderly patients who require less invasive treatment for BCC.
acitretin; basal cell carcinoma.
Proteus syndrome (PS) is a rare and sporadic disorder characterized by overgrowth of multiple tissues and a propensity to develop particular neoplasms. The clinical manifestations of PS include macrodactyly, vertebral abnormalities, asymmetric limb overgrowth and length discrepancy, hyperostosis, abnormal and asymmetric fat distribution, asymmetric muscle development, connective tissue nevi, and vascular malformations. We report a 16-year old female patient who manifested a number of these complications and review the Chinese literature about the diagnosis, natural history, and management of PS.
Proteus syndrome; clinical manifestation; diagnosis
How regulatory T cells (Treg) control autoreactive T cells has not been analyzed in animals with a normal T cell repertoire. Using endogenous viral superantigens (VSAg) as the primary self antigens and mice with the Scurfy mutation of FoxP3, we show here that the Treg defect causes preferential accumulation of autoreactive T cells. Interestingly, in the Scurfy mice, the proliferation of VSAg-reactive T cells was no more vigorous than that of non-VSAg-reactive T cells, which indicated that the preferential accumulation is not due to preferential proliferation. In contrast, VSAg-reactive T cells disappears in WT host despite their preferential proliferation. Importantly, when adoptively transferred into the newborn Scurfy mice, the Treg selectively kill autoreactive T cells without affecting their proliferation. The selective elimination is due to increased susceptibility of autoreactive T cells to Treg-mediated killing.
autoimmune diseases; clonal deletion; FoxP3; viral super-antigen; regulatory T cells
Dogma that the Treg prevents catastrophic autoimmunity throughout the lifespan relies on the assumption that the FoxP3 locus is transcribed exclusively in Treg. To test the assumption, we used the Rag2−/− and the Rag2−/− mice with the Scurfy mutation (FoxP3sf/y or FoxP3sf/sf) to evaluate FoxP3 expression outside of lymphoid system. Immunohistochemistry and real-time PCR revealed FoxP3 expression in breast epithelial cells, lung respiratory epithelial cells and in prostate secretory epithelial cells, although not in liver, heart and intestine. The specificity of the assays is confirmed as the signals were ablated by the Scurfy mutation of the FoxP3 gene. Using mice with green fluorescence protein (GFP) open-reading frame knocked into the 3′ untranslated region of the FoxP3 locus, we showed that the locus is transcribed broadly in epithelial cells of multiple organs. These results refute an essential underlying assumption of the dogma and question the specificity of FoxP3-based Treg depletion.
The progression of HIV disease has been markedly slowed by the use of highly active antiretroviral therapy (HAART). However, substantial genetic variation was observed to occur among different people in the decay rate of viral loads caused by HAART. The characterization of specific genes involved in HIV dynamics is central to design personalized drugs for the prevention of this disease, but usually cannot be addressed by experimental methods alone rather than require the help of mathematical and statistical methods. A novel statistical model has been recently developed to detect genetic variants that are responsible for the shape of HAART-induced viral decay curves. This model was employed to an HIV/AIDS trial, which led to the identification of a major genetic determinant that triggers an effect on HIV dynamics. This detected major genetic determinant also affects several clinically important parameters, such as half-lives of infected cells and HIV eradication times.
Hardy-weinberg equilibrium; bi-exponential function; quantitative trait loci; HIV dynamics; functional mapping.
The X-linked Foxp3 is a member of the forkhead/winged helix transcription factor family. Germ-line mutations cause lethal autoimmune diseases in males. Serendipitously, we observed that Foxp3sf/+ heterozygous mice developed cancer at a high rate. The majority of the cancers were mammary carcinomas in which the wild-type Foxp3 allele was inactivated and ErbB2 was over-expressed. Foxp3 bound and repressed the ErbB2 promoter. Deletion, functionally significant somatic mutations and down-regulation of the FOXP3 gene were commonly found in human breast cancer samples and correlated significantly with HER-2 over-expression, regardless of the status of HER-2 amplification. In toto, the data demonstrate that FOXP3 is an X-linked breast cancer suppressor gene and an important regulator of the HER-2/ErbB2 oncogene.