Listeria monocytogenes: a promising vector for tumor immunotherapy

Cancer receives enduring international attention due to its extremely high morbidity and mortality. Immunotherapy, which is generally expected to overcome the limits of traditional treatments, serves as a promising direction for patients with recurrent or metastatic malignancies. Bacteria-based vectors such as Listeria monocytogenes take advantage of their unique characteristics, including preferential infection of host antigen presenting cells, intracellular growth within immune cells, and intercellular dissemination, to further improve the efficacy and minimize off-target effects of tailed immune treatments. Listeria monocytogenes can reshape the tumor microenvironment to bolster the anti-tumor effects both through the enhancement of T cells activity and a decrease in the frequency and population of immunosuppressive cells. Modified Listeria monocytogenes has been employed as a tool to elicit immune responses against different tumor cells. Currently, Listeria monocytogenes vaccine alone is insufficient to treat all patients effectively, which can be addressed if combined with other treatments, such as immune checkpoint inhibitors, reactivated adoptive cell therapy, and radiotherapy. This review summarizes the recent advances in the molecular mechanisms underlying the involvement of Listeria monocytogenes vaccine in anti-tumor immunity, and discusses the most concerned issues for future research.

[Influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problem at the age of 6 years: a birth cohort study]

Objective: To investigate the influence of sleep fragmentation in infancy and toddler period on emotional and behavioral problems at the age of 6 years. Methods: Using a prospective cohort design, 262 children were extracted from mother-child birth cohort recruited from May 2012 to July 2013 in Renji Hospital, School of Medicine, Shanghai Jiao Tong University. Children's sleep and physical activities were assessed using actigraphy at 6, 12, 18, 24, and 36 months of age, from which the sleep fragmentation index (FI) at each follow-up point was calculated. Children's emotional and behavioral problems at 6 years of age were assessed using the strengths and difficulties questionnaire. Group-based trajectory model was applied to determine sleep FI in infancy and toddler period trajectory groups with Bayesian information criteria being used to determine the best fitting model. Children's emotional and behavioral problems between groups were examined with independent t test and linear regression models, etc. Results: A total of 177 children, with 91 boys and 86 girls, were included in the final analysis and were divided into 2 groups: high FI group (n=30) and low FI group (n=147). Compared with children in the low FI group, those in the high FI group presents with higher total difficulties score and higher hyperactivity or inattention score ((11.0±4.9) vs. (8.9±4.1), (4.9±2.7) vs. (3.7±2.3) scores, t=2.17, 2.23, both P<0.05, respectively), with the differences remaining significant after adjusting for covariates (t=2.08, 2.09, both P<0.05 respectively). Conclusion: High sleep fragmentation in infancy and toddler period is associated with more emotional and behavioral problems, especially hyperactivity or inattention problems, at 6 years of age.

Hdc-expressing myeloid-derived suppressor cells promote basal-like transition and metastasis of breast cancer

Metastases are the greatest contributors to death from breast cancer. Here, we identified a distinct subpopulation of luminal breast cancer characterized by cytokeratin 14 (CK14) expression in secondary colonies rather than primary tumors. This entity possessed a poorer prognosis compared to their CK14^- counterparts. Immunohistochemical analysis showed that myeloid-derived suppressor cells (MDSCs) were recruited into the tumor microenvironment and exhibited a close spatial relationship with CK14⁺ cancer cells. We demonstrated that histidine decarboxylase (Hdc) is capable of labeling myeloid-biased hematopoietic stem cell/progenitor cell (HSC/HSPC) and immature myeloid cells infiltrating in tumor tissues. FACS data obtained from Hdc-CreER^T2; eGFP; MMTV-PyVT female mice revealed an increased percentage of Hdc⁺ PMN-MDSCs in metastatic masses. Hdc⁺ PMN-MDSCs expressed high levels of canonical Wnts, including Wnt2, Wnt4, Wnt5a, and Wnt7b, to aberrantly activate Wnt/β-catenin signaling in CK14⁺ malignant cells. β-catenin translocated from the membrane into the cytoplasm and nucleus. Targeted ablation of Hdc⁺ PMN-MDSCs-derived Wnts through porcupine^flox/flox and iDTR transgenic models hampered the metastatic cascade, making Hdc⁺ immature myeloid cells an attractive candidate for tailed immunotherapies.

Extraovarian Brenner tumor in the uterus: a case report and review of literature

BACKGROUND

Extraovarian Brenner tumors (EOBTs) are extremely rare and can be observed incidentally in both female and male patients, raising concerns regarding the origin of Brenner tumors.

CASE PRESENTATION

A 53-year-old postmenopausal woman presented with a nodular lesion in the left side of the corpus uteri, which was found at a routine health check. Macroscopically, the lesion appeared as a solid nodule with a yellowish-gray cut surface, approximately 6 cm in greatest diameter. Microscopically, the lesion consisted of well-defined epithelial nests and spindled stromal cells. Parenchymal cells expressed CK7, GATA3, CK5/6, 34βE12, and p63. A single layer of cavity-lined cells with umbrella-like shape showed apical Uroplakin III positivity. Stromal cells were positive for SMA, ER, and PR. The final diagnosis was EOBT and the patient was followed for 2 months with no recurrence.

CONCLUSIONS

We report here the third case of EOBTs in the uterus. The combination of morphologic and immunohistochemical results supported the involvement of urothelial metaplasia in the development of EOBTs. The similarities between EOBTs and Walthard nests made Müllerian epithelium an attractive candidate as the cellular origin. Changes of tissue structure or sex hormones imbalance may lead to the translocation of Müllerian remnants to distant organs, explaining the pathogenesis of EOBTs.

Epithelioid sarcoma of the scalp: a case report and literature review

Epithelioid sarcoma (ES) is an aggressive mesenchymal tumor exhibiting bi-directional phenotypes. According to its proclivity for different sites, ES can be subdivided into two categories: distal and proximal variants. Proximal ES often affects the truncal tissue, thighs, head, and neck. Accumulating evidence indicates that several locations in the head, including the orbital, gingival, and nasal cavities, are involved in ES. However, the underlying mechanisms of ES carcinogenesis and progression are largely unknown, including and especially the reason why the tumor cells are positive for both epithelial and mesenchymal classical markers. Thus, we wish to share a rare case of ES in the scalp and its clinical and molecular features. Only 9 cases to date have been reported. An 80-years-old man had sustained a painful swollen mass in his scalp for three months. A diagnosis of epithelioid sarcoma was established based on the combination of the histopathological and immunohistochemical findings. The tumor cells were positive for both mesenchymal (vimentin and S100) and epithelial markers (pan-cytokeratin). This case suggests that ES can be derived from the soft tissue of the scalp. The tumor cells co-expressed biomarkers of epithelial and mesenchymal cells, suggesting the mesenchymal-epithelial transition (MET) may be involved.

Synchronous multiple primary gastrointestinal cancers with CDH1 mutations: A case report

BACKGROUND

Synchronous multiple primary cancers (SMPC) mean two or more malignant tumors occurring simultaneously and with different origins no matter what types they are or where they are located. The carcinogenesis of SMPC often involves variations of some specific genes. However, the correlation between CDH1 mutations and synchronous multiple primary gastrointestinal cancers is largely unknown.

CASE SUMMARY

A 62-year-old woman had sustained abdominal pain for one week and visited our hospital. Gastrointestinal endoscopy revealed multiple small polypoid lesions in both the stomach and colorectum. Computed tomography and laboratory results were within normal limits. Pathological evaluation confirmed signet ring cell carcinoma without obvious metastatic evidence. Malignant cells showed negativity for E-cadherin and positivity for β-catenin in the cytoplasm and nucleus. DNA sequencing performed on paraffin-embedded tissue revealed two exactly coincident alterations in CDH1, C.57T>G and C.1418A>T.

CONCLUSION

This case suggests that the combination of CDH1 mutations and WNT/β-catenin signaling activation contributes to the carcinogenesis of gastrointestinal SMPC.

[Investigation of dose-dependent association between bedtime routines and sleep outcomes in infants and toddlers]

Objective: To investigate the current bedtime routine among Chinese children less than 3 years of age and explore its dose-dependent association with sleep duration and sleep quality. Method: Healthy full-term born children aged 0-35 months were selected by stratified cluster random sampling method from 8 provinces in China following the "Hospital of Province-City-County" sampling technical route during 2012-2013.Brief Infant Sleep Questionnaire(BISQ) was used to assess sleep conditions of these children.Children's personal and family information was obtained by Shanghai Children's Medical Center Socio-demographic Questionnaire.Both of these questionnaires were filled in by parents. The effects of bedtime routine on children's sleep duration and quality were analyzed by multivariate analysis of variance. Result: The children's average age was(12±10) months(n=1 304), of whom 689 were males (52.8%, 689/1 304). There were 48.5%(632/1 304)of the parents reported that their children had not established regular sleep routines. There was a consistent dose-dependent association between bedtime routine and sleep duration, as well as other indicators for sleep quality (all P<0.05). The more regular the sleep routines, the longer the sleep duration, the earlier the children went to sleep, the shorter the sleep onset latency, the fewer the nighttime wakeup and the shorter the nighttime waking.The nighttime sleep duration was significantly longer for those with a bedtime routine 'every night' than those who 'never' had a bedtime routine (9.5(95%CI: 9.4-9.6)vs. 8.9(95%CI: 8.6-9.3)h, t=3.345, P=0.001). Compared with children who never had bedtime routines, children with regular bedtime routines had fewer night wakeup (1.3(95%CI: 1.2-1.4) vs. 2.4( 95%CI: 2.0-2.9), t=3.182, P=0.001) and shorter night waking duration(16.6(95%CI: 14.6-18.8) vs. 59.2 (95%CI: 47.0-72.7)min, t=6.383, P<0.01). Conclusion: The percentage of children who have established regular bedtime routine is low in China. There is significant dose-dependent association between regular bedtime routine and sleep outcomes, especially sleep quality. The more regular the sleep routines, the better the sleep quality.

Analysis of epithelial-mesenchymal transition markers in the histogenesis of hepatic progenitor cell in HBV-related liver diseases

Background

The origin and heterogeneity of hepatic progenitor cells (HPCs) remain unclear. This study aimed to investigate the involvement of epithelial-mesenchymal transition (EMT) in the histogenesis of HPCs.

Methods

Surgical liver specimens from patients with HBV-related hepatitis and cirrhosis were investigated with double immunofluorescence labeling to detect antigens associated with HPCs and EMT. Ductular reactions were subjected to quantitative reverse transcription PCR following isolation by laser capture microdissection. Electron microscopic examination was performed to find an ultrastructural evidence of EMT.

Results

The number of EpCAM-positive HPCs was proportional to the disease severity. The S100A4 expression of HPCs was firstly observed in mild hepatitis and increased significantly in moderate hepatitis, but decreased in severe hepatitis and cirrhosis. The levels of MMP-2, Twist, and Snail increased in direct proportion to the number of HPCs. Some hepatocytes adjacent to portal tracts in cirrhosis showed positivity for MMP-2. Although CK7 and E-cadherin levels decreased in mild and moderate hepatitis, HPCs re-expressed both of them in severe hepatitis and cirrhosis. However, HPCs expressed neither vimentin nor αSMA. The relative mRNA expression levels of EpCAM and EMT-associated markers supported immunohistochemical results. Electron microscopic examination demonstrated the existence of intercellular junctions among HPCs, cholangiocytes, and intermediate hepatocyte-like cells.

Conclusion

We provided preliminary evidence for the involvement of EMT in the histogenesis of HPCs from cholangiocytes in HBV-related liver diseases. HPCs may re-transdifferentiate into hepatocytes, and the differentiation direction depends, at least in part, on interactions between HPCs and the surrounding microenvironment, especially the non-resolving inflammation caused by HBV infection.

[Comparison on metabolic disorders and uric acid levels between patients with primary aldosteronism and essential hypertension]

Objective: To compare the incidence of metabolic disorders and uric acid (UA) levels between patients with primary aldosteronism (PA) and essential hypertension (EH), and to explore factors associated with UA levels in these patients. Methods: A total of 117 PA and 117 EH patients individually matched by sex, age, blood pressure and duration of hypertension were recruited from in-hospital patients who were hospitalized in our department because of suspicion of secondary hypertension from January 2008 to December 2014. Clinical data including metabolic disorders and UA levels were analyzed. Results: (1) Body mass index (BMI), waist circumference, plasma triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), free fatty acid (FFA) were significantly higher in EH than in PA group (all P<0.05). Prevalence of diabetes mellitus or impaired glucose tolerance (DM+ IGT) was significantly higher in EH than in PA group (41.9% (49/117) vs. 17.1% (20/117), P<0.01). The prevalence of metabolic syndrome (MS) was also significantly higher in EH than in PA group (51.3% (60/117) vs. 24.8% (29/117), P<0.01). (2) EH patients had higher homeostasis model assessment for insulin resistance (HOMA-IR) and lower insulin sensitivity index composite (ISI comp) than PA patients, but basic insulin secretion index (HOMA-β) and modified β cell function index (MBCI) were significantly lower in PA than in EH group (P<0.05). (3) With regard to target organs damages, PA patients revealed higher 24-hour urinary protein, urinary albumin excretion rate (UAER), urinary IgG, urinary α-1 microglobulin, left ventricular mass index and lower urine specific gravity than EH patients (all P<0.05). There was no significant difference in estimated glomerular filtration rate (eGFR) between two groups (P=0.103). (4) UA level was significantly lower in PA group than in EH group ((314.00±89.52) μmol/L vs. (379.16±101.25) μmol/L, P<0.01). Higher plasma aldosterone concentration and lower plasma renin activity were associated with lower UA level in PA group. Conclusions: Compared with sex, age and hypertension duration matched EH patients, PA patients revealed lower UA level and less severe abnormalities of glucose and lipid metabolism, but are associated with severer renal and cardiac damages. The reduced UA level in PA patients is possibly due to the high plasma aldosterone concentration and low plasma renin activity.

Cutaneous clear cell/signet-ring cell squamous cell carcinoma arising in the right thigh of a patient with type 2 diabetes: combined morphologic, immunohistochemical, and etiologic analysis

BACKGROUND

The clear cell/signet-ring cell variant of cutaneous squamous cell carcinoma (cSCC) is extremely rare. Its carcinogenesis has consistently been linked to ultraviolet radiation and HPV in the literature. However, there is little definite information about the contribution of diabetes mellitus (DM) to cSCC.

CASE PRESENTATION

A 78-year-old Chinese woman with type 2 DM presented with a mushroom-like lump in her right thigh. Histological findings revealed that the lesion was mainly composed of clear cells and signet-ring cells. The septa of vacuoles in cytoplasm displayed positivity for periodic acid schiff (PAS) and cytokeratins such as AE1/AE3, CK5/6, CK14, and CK19. Malignant cells did not express CK7, CK8, CK18, CK20, p16, p53, or c-erbB-2, and the Ki-67 index was less than 5 %. We further explored the etiology of clear cell/signet-ring cell cSCC using human papillomavirus (HPV) type-specific PCR and genotyping and confirmed that the patient was not infected with HPV. Nucleus positivity for p63 indicated the involvement of the p53 family in the lesion. Meanwhile, the expression of fibroblast growth factor receptor-2 (FGFR2), a downstream effector of p63, was upregulated in tumor cells.

CONCLUSIONS

This study provides the first report on the clear cell/signet-ring cell variant of cSCC found in the right thigh of a patient with type 2 DM. Metabolic imbalance in addition to conventional pathogens such as UV and HPV may contribute to the development of the lesion via p63/FGFR2 axis.

Degradation Kinetics of Fluorouracil-Acetic-Acid-Dextran Conjugate in Aqueous Solution

The degradation kinetics of fluorouracil-acetic-acid-dextran conjugate (FUAC-dextran) was investigated in various buffer solutions with different pH value and physiological saline solution at 60 degrees C and 37 degrees C, respectively. The hydrolytic reaction displayed pseudo-first-order degradation kinetics. Hydrolytic rate constant obtained was the function of pH value and independent of species of buffering agents. The smallest rate constant was observed at pH round 3.00. The activation energy of the hydrolytic reaction was estimated from Arrhenius equation as 88.73 +/- 6.00 kJ.mol-1. The special base catalytic degradation of the conjugate was observed from acidic to slight alkaline condition and the special base catalytic rate constants were calculated. The conjugate was more stable in physiological saline than that in buffer solution at pH 7.00 or 9.00 at 37 degrees C. The results revealed that the conjugate was stable in acidic condition and will degrade in alkaline condition.

Effects of diethylhexyl phthalate (DEHP) on INSL3 mRNA expression by Leydig cells derived from mouse embryos and in newborn mice

Insulin-like factor 3 (INSL3) regulates testicular descent during fetal life, and Insl3 gene inactivation results in cryptorchidism. Little is known, however, about whether the plasticizer diethylhexyl phthalate (DEHP), a contaminant found widely in the environment, influences INSL3 expression. In this study, primary cultures of Leydig cells from mouse embryos were treated in vitro with DEHP. We also treated pregnant mice with DEHP from gestation day 12 to postnatal day 3 in order to study the effect of DEHP in vivo. INSL3 mRNA expression levels in primary Leydig cell cultures and in the testes of newborn mice were significantly lower following DEHP treatment. DEHP also caused detrimental morphological changes in both primary cultures of Leydig cells and the testes of newborn mice. These results suggest that the downregulation of INSL3 mRNA by DEHP might cause abnormalities of gubernacular development, which might be one of the mechanisms for development of cryptorchidism.

Uptake of liposomes by cultured cardiomyocytes

Small unilamellar liposomes (SUV) of different phospholipid/polymer composition were labeled with NBD-PC, which served as a bilayersituated fluorescence marker. Neonatal cardiomyocytes were incubated with liposomes and then the cell-associated fluorescence was measured. The factors influencing the liposome uptake by cardiomyocytes such as concentration of lipid, time of incubation, membrane fluidity of liposomes, charge lipid/polymer modification of liposomes and anoxia of cultured cardiomyocytes were investigated. The liposome uptake by cardiomyocytes increased dose-dependently and time-dependently. Liposome uptake was strongly influenced by the electrical charge and modified polymer. After 2 h incubation, the uptake of positively charged liposomes was 1.7-fold higher than that of negatively charged one and both higher than that of the neutral one. The presence of PE-PEG2000 distinctly reduced the liposome uptake and the difference between the uptake of charged and neutral liposome. Anoxia increased the uptake of liposome at the first hour (increased 20%), but after 2 h incubation the liposome uptake by hypoxia cellswas less than that of normoxia cells (decreased 18%). Mechanisms involved are also discussed.

Gene profiling involved in immature CD4+ T lymphocyte responsible for systemic lupus erythematosus

We attempted to characterize the genes expression of CD4+ T lymphocytes for the pathogenesis of systemic lupus erythematosus (SLE). Genomewide gene expression profiles of CD4+ T cells, which were isolated from the disease severe activity (T4-1s) and nonactivity (T4-2s) with an SLE patient by using long serial analysis of gene expression (LongSAGE). We picked out 289 genes matching to Unigene cluster with different expression more than four copies between T4-1s and T4-2s libraries and analyzed their roles from the collectedly published articles of PubMed by genes functional clustering. The genes functions were related to a diverse cellular process including: (1) most of these genes were associated with CD4+ T cells functions, particularly related to cellular developments; (2) Ras pathway genes as RANBP10, GMIP, RASGRP2 and ARL5 might be responsible for the abnormal development of CD4+ T cells of SLE; (3) HIG2, TCF7, KHSRP, WWP1, SMAD3, TLK2, AES, CCNI and PIM2 belong to Wnt/beta-catenin way, they could play roles in modulating proliferation and differentiation of T lymphocytes; (4) uncertain viral infections may initiate autoimmunity because high levels expression genes were detected in T4-1s such as TRIM22, IER2, ABCE1, DUT, G1P2, G1P3, HNRPUL1, EVER2, IFNAR1, TNFSF14, TMP21 and PVRL2; and (5) apoptosis relating genes as EIF3S8, SH3BGRL3, GPX4, TOSO, PFDN5, BIN1, XIAPAF1, TEGT and CUGBP2 may contribute to over uploading of selfantigens in SLE cells. Abnormalities findings of multiple genes expression involving with a variety of CD4+ T cells process might be meaningful to understanding the pathogenesis of SLE, and immature CD4+ T cells may be responsible for SLE.

Enhanced oral bioavailability of breviscapine after encapsulation in a liposomal formulation

This report firstly describes the pharmacokinetic study of liposomal breviscapine (LB) after oral administration in rats. The mean Cmax and AUC(0-->t) of LB were 3.3 and 3.1-fold higher than those of breviscapine solution (BS). The oral absorption of breviscapine was significantly increased after encapsulation in the liposomal formulation.

Surface modification of liposomes for cardiomyocytes targeting in vitro

The effect of novel 3-{4-[2-hydroxyl-(1-methyl ethylamine) propyl oxygen]phenyl}propionic acid cetylester (PAC) as a surface modification ligand on the delivery of liposomes into cultured cardiomyocytes was investigated. Small unilamellar liposomes with and without PAC (PAC-liposome and Plain-liposome) were labeled with a fluorescence marker. The cultured neonatal cardiomyocytes were incubated with liposomes under normoxia or hypoxia conditions, and then the cell-associated fluorescence was measured. A high affinity of the PAC-liposomes to cardiomyocytes was observed. The amount of cell uptake of PAC-liposomes under normoxia conditions was 4-fold higher than that of plain-liposome, and the increase was 8.5-fold when hypoxia occured. The results suggested that PAC is a potential surface modification ligand for liposome targeting the ischemic myocardium.

A comparative study of third-order nonlinear optical properties of silver phenylacetylide and related compounds via ultrafast optical Kerr effect measurements

A comparative study of the third-order nonlinear optical properties, via the newly developed heterodyned optical Kerr effect (OHD-OKE) measurements, of silver phenylacetylide and related compounds is reported. [AgC[triple bond]CC(6)H(5)](n) (1) was found to exhibit efficient third-order nonlinear optical susceptibility chi((3)) of 2.4 x 10(-14) esu, and second hyperpolarizability gamma of 9.07 x 10(-32) esu. These results are compared with those of two related silver phenylacetylide compounds, namely, a double salt, (silver phenylacetylide).(silver tert-butylthiolate) [AgC[triple bond]CC(6)H(5).AgS(t-C(4)H(9))](n) complex (2), and a cluster, triphenylphosphine silver phenylacetylide tetramer, [(C(6)H(5))(3)PAgC[triple bond]CC(6)H(5)](4) (3), as well as that of the related organic polymer polyphenylacetylene (4). These four compounds represent different types of phenylacetylide derivatives: 1 is an organometallic polymer, 2 a polymeric double salt, 3 a discrete metal cluster, and 4 an organic polymer. It was found that the third-order optical nonlinear response was enhanced by the incorporation of silver d electrons into the delocalized conjugated organic pi system, and its magnitude is highly dependent upon the extent of the pi delocalization. Specifically, the relative magnitudes of chi((3)) and gamma follow the order silver phenylacetylide polymer (1) > (silver phenylacetylide).(silver tert-butylthiolate) double salt (2) > polyphenylacetylene polymer (4) > tetrameric (triphenylphosphine silver phenylacetylide)(4) cluster (3). The observed trend may be attributed to the decreasing length of pi conjugation. It is interesting to note that the incorporation of Ag(I) into the polymeric framework of polyphenylacetylene enhances the chi((3)) by 25-fold for the same degree of polymerization (n = 7). The signs of chi((3)) and gamma, which are related to the response mechanisms, were found to be solvent dependent.

HLA-DQ8 transgenic and NOD mice recognize different epitopes within the cytoplasmic region of the tyrosine phosphatase-like molecule, IA-2

Type 1 diabetes mellitus is strongly associated with HLA-DQ8 in humans and I-A(g7) in the NOD mouse. The disease is characterized by loss of tolerance to auto-antigens such as GAD, insulin, and the protein tyrosine phosphatase-like molecule, IA-2. We identified T cell epitopes on the intracytoplasmic region of IA-2 by immunizing DQ8/NOD, DQ8/B10, and NOD mice with overlapping 18 mer peptides in CFA. We identified four peptides presented both by DQ8 and NOD, five DQ8 specific peptides, and six NOD specific peptides. Both mouse lines failed to respond to ten peptides. We demonstrated MHC class II and CD4 restriction of proliferative responses using appropriate blocking antibodies. To understand the role of non-MHC genes in the generation of immune response to the islet auto-antigen, we evaluated cytokine secretion following immunization of DQ8 transgenic mice with strongly immunogenic peptides. The NOD background resulted in increased secretion of cytokines. In conclusion, we have identified IA-2 peptides that induce lymphoproliferative responses in DQ8 transgenic and NOD mice and shown that these peptides stimulate production of Th1 and Th2 cytokines.

Antibodies to IA-2 and GAD65 in type 1 and type 2 diabetes: isotype restriction and polyclonality

OBJECTIVE

To determine the isotypes and clonality of antibodies to GAD (GADA) and IA-2 (IA-2A) in patients with type 1 and type 2 diabetes.

RESEARCH DESIGN AND METHODS

We studied the following consecutive series of patients who attended a diabetes center for antibodies to GADA and IA-2A: 52 newly diagnosed type 1 diabetic patients, 199 type 2 diabetic patients, 200 control patients, and a cohort of 34 nondiabetic identical twins of patients with type 1 diabetes (15 of whom developed diabetes) who were followed prospectively.

RESULTS

GADA or IA-2A were detected in 37 (71%) type 1 diabetic patients compared with only 10 (5%) type 2 diabetic patients (P<0.0001). Both GAD and IA-2 antibodies, regardless of the type of diabetes, were usually subclass restricted to IgG1 and were polyclonal. IgM, IgG3, and IgE isotypes were also detected, but all isotypes of GADA and IA-2A were less prevalent than IgG1 (P<0.017 for either antibody). There was no evidence of spreading or switching of isotypes before the onset of type 1 diabetes.

CONCLUSIONS

These observations suggest that the pathogenesis of antigen-specific antibodies in type 1 and type 2 diabetes is similar and probably involves a chronic nonrandom antigen-driven polyclonal B-cell activation that is consistent with a Th1-type immune response.

Molecular determinants of polyreactive antibody binding: HCDR3 and cyclic peptides

Human monoclonal antibody 63 (mAb63) is an IgM/lambda polyreactive antibody that binds to multiple self and non-self antigens. The molecular basis of polyreactivity is still unclear. The present study was initiated to prepare a recombinant Fab of mAb63 and use it to study the determinants involved in polyreactivity. The baculovirus system was employed to express large amounts of mAb63 Fab in Sf9 cells. Our experiments showed that infected Sf9 cells secreted a soluble 50-kD Fab heterodimer that bound to multiple self and non-self antigens. The antigen-binding activity of mAb63 Fab was inhibited by both homologous and heterologous antigens. To study in more detail the molecular determinants involved in polyreactivity, the heavy chain complementarity-determining region 3 (HCDR3), which is known to play a key role in the binding of monoreactive antibodies to antigens, was subjected to site-directed mutagenesis. A single substitution, alanine for arginine, at position 100A resulted in complete loss of antigen-binding activity. The 19 amino acids comprising the HCDR3 of mAb63 were then synthesized and a cyclic peptide prepared. The cyclic peptide showed the same antigen-binding pattern as the parental mAb63 and the recombinant mAb63 Fab. A five amino acid motif (RFLEW), present in the HCDR3 of mAb63, was found by searching the GenBank in three of 50 other human polyreactive antibodies, but in none of nearly 2500 human antibodies thought to be monoreactive. It is concluded that HCDR3 plays a major role in polyreactivity and that in some cases cyclic peptides comprising the HCDR3, by themselves, may be polyreactive.

Urban-rural comparison of nutrient intake by adult women in Shaanxi Province, China

Triplet surveys were conducted in the city of Xi' an and two villages (one in the vicinity and the other at a distance) in Shaanxi Province in China in October-November (when agricultural activities were low), 1997, to elucidate nutrient intakes with a focus on possible urban-rural differences. Total food duplicate samples were collected from non-smoking and non-habitually drinking adult healthy women (about 50 subjects per site and 149 in total). The nutrient intakes were estimated from the weight of food items in reference to national food composition tables. On average, the women took 1873 kcal energy, 54 g protein and 37 g lipid per day, with a lipid energy ratio of 18.4%. Both excess and insufficient energy intake was observed as a result of food intake analysis and body mass index determination. With regard to minor nutrient intakes, insufficiency was serious in the case of calcium, vitamin A and vitamin B2, but not with iron. Whereas dependency on plant foods for sources of energy and protein was common to the three regions, Xi' an people consumed more animal foods than those in the villages. Intake of fish and shellfish was quite low throughout the three regions. Among the four types of cereals, wheat was consumed most substantially in the three regions and in three meals (except for the village where people essentially did not take lunch in reflection of low agricultural activities), whereas rice was consumed more in Xi' an than in the two villages. Maize consumption was higher in the two villages (especially for breakfast) than in the city. In contrast, foxtail millet (although in small amounts) was taken primarily in Xi' an and only at the time of breakfast.

Expression, characterization, processing and immunogenicity of an insulin-dependent diabetes mellitus autoantigen, IA-2, in Sf-9 cells

Autoantibodies to a 64-kD protein and a 40-kD tryptic fragment from pancreatic islets have been detected at high frequency in the sera of patients with insulin-dependent diabetes mellitus (IDDM). IA-2, a newly isolated transmembrane protein tyrosine phosphatase, is a major islet cell autoantigen in IDDM and the precursor of a 40-kD tryptic fragment. To express large quantities of recombinant IA-2 protein and analyse post-translational modifications we expressed full-length human IA-2 in baculovirus-infected Sf-9 cells. IA-2 expression was analysed by Western blot and by immunoprecipitation of 35S-methionine-radiolabelled proteins with rabbit antisera or IDDM sera. A 120-kD IA-2 protein was detected during the early, but not the late, phase of the infection. Pulse-chase experiments showed that the 120-kD protein was processed into fragments of 64 kD and smaller fragments of approximately 50 kD, 38 kD and 32 kD. The 64-kD fragment appeared as a doublet. Tunicamycin and PNGase F treatment down-shifted the 120-kD protein and the 64-kD doublet into lower molecular weight bands, suggesting that both were glycosylated. Trypsin treatment converted the 120-kD protein and the 64-kD doublet into a 40-kD fragment. Baculovirus-expressed IA-2 was as sensitive or slightly more sensitive than in vitro translated IA-2 in detecting autoantibodies to IA-2: 66% of sera from newly diagnosed IDDM patients reacted with baculovirus-expressed IA-2 compared with 59% of the same sera which reacted with in vitro translated IA-2. It is concluded that baculovirus-expressed IA-2 is a good source of autoantigen and that a number of lower molecular weight fragments with which IDDM autoantibodies react are derived from the 120-kD full-length IA-2 molecule.

A molecular basis for affinity modulation of Fab ligand binding to integrin alphaIIb beta3

The Arg-Gly-Asp (RGD) sequence within the third complementarity-determining region (CDR3) of the heavy chain (H3) is responsible for the binding of the recombinant murine Fab molecules, AP7 and PAC1.1, to the platelet integrin alphaIIbbeta3. AP7 binding is minimally influenced by the conformational state of this receptor, whereas PAC1.1 binds preferentially to the activated state of the receptor induced by platelet agonists. To study the molecular basis for this functional difference, we replaced the AP7 H3 loop (HPFYRGDGGN) with all or segments of the analogous sequence from PAC1.1 (RSPSYYRGDGAGP). AP7 Fd (VH domain + Cgamma1 domain) segments containing these H3 loop sequences were expressed as active Fab molecules by coinfection of Spodoptera frugiperda cell lines with recombinant baculoviruses containing Fd and AP7 kappa chain cDNA. Replacement of the entire AP7 H3 loop with that from PAC1.1 generated the mutant AP7.3 Fab molecule, which bound selectively to either activated, gel-filtered platelets or to purified alphaIIbbeta3 in a manner identical to that of PAC1.1. Identical results were obtained when solely the sequences flanking the amino side of RGD within the respective H3 loops were exchanged. AP7.3 and PAC1.1 exhibited saturable but submaximal binding to activated gel-filtered platelets. Relative to AP7, the number of AP7.3 or PAC1. 1 Fab molecules bound per platelet was 17% in the presence of 1 m Ca2+ + 1 mM Mg2+ or 40% in the presence of 10 microM Mn2+. The ratio of Fab molecules bound after versus before activation (mean =/- S.D.; n = 3) was: for AP7.3, 9.8 =/- 0.6; for PAC1.1, 8.8 +/- 0.3; and for AP7, 1.4 =/- 0.2. In addition, AP7 bound to the stably expressed integrin mutant alphaIIbbeta3(S123A), whereas AP7.3 and PAC1 did not. Because AP7.3 behaves in every respect like PAC1.1, we conclude that the ability of RGD-based ligands to distinguish activated from resting conformations of the integrin alphaIIbbeta3 can be regulated by limited amino acid sequences immediately adjacent to the RGD tripeptide. Furthermore, those Fab molecules that exhibit increased selectivity for the activated conformation of alphaIIbbeta3 bind to a subpopulation of this integrin on platelets that is modulated by divalent cations.

Epitopic characterization of neuropeptide Y (NPY) by alanine-scanning mutagenesis

Characterization of the epitopic structures of neuropeptide Y (NPY) has been studied by alanine-scanning mutagenesis, based on our previous investigation of a panel of six murine anti-NPY IgM monoclonal antibodies. To evaluate the structural requirement for these anti-NPY IgM antibodies, recognition variants of the native sequences of the NPY fragment (19-36) were prepared by single alanine substitutions in residues 22 and 25-36. Their binding to these antibodies was examined by competitive inhibition assays. The results demonstrated that the epitopic structures are largely confined to residues 25-36 of NPY and the C-terminal residues of NPY are essential for these anti-NPY IgM antibodies recognition. It emphasizes the notion that even small regions of a protein consisting of as few as 15 residues (22-36) can exhibit multiple epitopic structures. In several anti-NPY IgM antibodies, pairs of residues on opposite faces of the alpha-helix interact with the antibody site, which indicates that the antibody site consists either of a cavity or a deep groove either of which encompasses the alpha-helical segment sufficiently to allow simultaneous contact with most of the residues of this segment.

Assessment of autopsic samples of carotid atherosclerosis in the aged by intravascular ultrasound

To assess the value of intravascular ultrasound in detecting carotid atherosclerosis, we compared the ultrasound images of 48 carotid artery segments from autopsies with their histological findings. The results showed that by intravascular ultrasonography one could distinguish between elastic and muscular tissues of arteries, determine the lesions of fibroelastosis and calcified plaques on arterial wall, and precisely measure the wall thickness, inner and outer diameter, luminal area and cross-sectional area of arteries with a high correlation between the data measured from ultrasonography and histological study (r values were 0.98, 0.97, 0.97, 0.96 and 0.96, respectively). This study suggests that intravascular ultrasound might be effectively used for morphological study and detection of atherosclerotic lesions in vivo.

Determinants of specificity of a baculovirus-expressed antibody Fab fragment that binds selectively to the activated form of integrin alpha IIb beta 3

PAC1 is an IgM kappa murine monoclonal antibody that, like the Arg-Gly-Asp-containing ligand fibrinogen, binds to integrin alpha IIb beta 3 only on activated platelets. The unique binding properties of PAC1 may be determined by its large size, its multivalency, and by variable region sequences, including an Arg-Tyr-Asp at residues 100A-C in H-CDR3. To study the molecular determinants of PAC1 function, baculoviruses containing cloned cDNA for the Fd heavy and kappa light chains of PAC1 were used to co-infect Sf9 insect cells. Infected cells secreted a soluble, monovalent, 50-kDa Fab fragment that bound saturably to agonist-stimulated platelets but not to resting cells. Fab binding was inhibited > 85% by 10 mM EDTA, 1 mM RGDS, 1 mM fibrinogen gamma 397-411, or 12 microM fibrinogen, but not by 1 mM RGES. Compared to PAC1 IgM, a 60-fold higher molar concentration of PAC1 Fab was required for half-maximal binding to platelets or for half-maximal inhibition of fibrinogen binding. PAC1 Fab bound to an activated form of alpha IIb beta 3 expressed in Chinese hamster ovary cells, but not to the resting form of the receptor in these cells or to alpha v beta 3 in human endothelial cells. Conversion of Asp100C to Glu by site-directed mutagenesis rendered the antibody inactive, indicating that the Arg-Tyr-Asp sequence in H-CDR3 is essential for PAC1 recognition of alpha IIb beta 3. Binding of fibrinogen or PAC1 IgM to platelets induced tyrosine phosphorylation of a 140-kDa platelet protein, but binding of PAC1 Fab did not. These studies demonstrate that the specificity of PAC1 for activated alpha IIb beta 3 is determined by an integrin recognition sequence within H-CDR3. However, the strength of this binding interaction and the ability of PAC1 to trigger signaling in platelets also depend on antibody valency.

[Protective action of blumeatin against experimental liver injuries]

Blumeatin (Blu, 5,3',5'-trihydroxy-7-methoxy-dihydro-flavone) was first isolated from Blumea balsamifera DC by Department of Chemistry, Sunyatsen University of China. Blu ip inhibited the increase of serum alanine aminotransferase (AAT) and liver triglyceride and increased serum triglyceride, beta-lipoprotein, and liver glycogen content in CCl4-intoxicated rats. Histological lesions of liver were less severe than those of hepatic injury control. Blu ip 0.65 and 3.25 mg.kg-1 inhibited the increase of serum AAT and hepatic TG in thioacetamide (TAA)-intoxicated mice. Blu ip shortened the pentobarbital sleeping time in CCl4-intoxicated mice. It suggested that Blu could protect liver against injury induced by CCl4 and TAA.

Primary B-cell response to neuropeptide Y and bovine pancreatic polypeptide

An analysis of the murine primary response to protein epitopes has been made with two small highly structured proteins, neuropeptide Y (NPY) and bovine pancreatic polypeptide (BPP), both of 36-amino acid residue length and containing helical structures. A group of cell lines producing monoclonal IgM antibody have been prepared consisting of six anti-NPY and two anti-BPP. The VH nucleotide sequences have been determined and characterized as germ-line either by identity to established germ-line sequences or by inference from the germ-line character of the D and JH segments. The intrinsic association constants for the homologous ligands have been estimated to range from 10(4) to 10(7) M-1 based on competitive ELISA. No severe restriction in the utilization of VH families, D segments or JH segments appears to be involved in this response. Among the eight cell lines, three VH families were represented as well as all three families of D segments and all of the JH segments, although some preference for JH3 was indicated. The length of the N(D)N sequences was also not subject to restriction, ranging from 9 to 29. Two unusual features of the CRD3s were noted, one involving the utilization of an uncommon DSP2 segment and the other the apparent occurrence of a D-D fusion.

Electrochemical superoxidation of flavins: generation of active precursors in luminescent model systems

Using 3-methyllumiflavin and tetraacetyliriboflavin as examples, we have shown that the socalled "fully oxidized" flavins can be "superoxidized" at an anodic potential of 1.8 to 1.9 V giving flavin radical cation transients which are rapidly transformed in subsequent chemical reactions. An attack by H2O subsequent to the superoxidation of 3-methyllumiflavin provides a route for the formation of 4a-hydroxy-3-methyllumiflavin radical cation, as evident from the subsequent decomposition to the protonated form of the starting flavin. When 3-methyllumiflavin is superoxidized in the presence of a base, a recycling process occurs, allowing superoxidized flavin to be trapped in a slower, competitive conversion. The relatively more stable trapped product is active in reacting with H2O2 to emit chemiluminescence. Electrochemical oxidation of H2O2 in acetonitrile at 1.30 V in the presence of an oxidized flavin results in a direct protonation of the flavin by H+ generated from the electrolysis of H2O2. Minor reactions presumably provide alternative formations of the 4a-hydroperoxy- and 4a-hydroxy-flavin radical cation transients by the direct addition of HOO. and HO. radicals, which also arise in the oxidation of H2O2, to protonated flavin. Under such conditions the superoxidized flavin radical cation is apparently also formed, either directly or by process(es) such as decomposition of the flavin 4a-adduct radical cations. Subsequent reductions of either the superoxidized flavin or the flavin 4a-adduct radical cations lead to an almost steady level of luminescence.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinicopathologic analysis of 487 thyroid tumors]

In this paper, 487 cases of thyroid tumor, 387 (79.5%) benign and 100 (20.5%) malignant, were analysed clinicopathologically. Benign thyroid tumor was divided into three types: papillary, follicular and atypical adenomas; malignant thyroid tumor into five types: papillary, follicular, undifferentiated, medullary and squamous cancers. In the benign variety, follicular adenoma had the highest incidence (98.2%) and in the malignant tumors, papillary cancer ranked first (62%). In this series, there were two cases of carcino-sarcoma. The sex ratio of male and female was 1:1.62 for the whole series, 1:1.70 for benign and 1:1.38 for malignant tumors. The peak age was 21 to 40 years with a median of 35 for benign and 31 to 50 years with a median of 43 for malignant tumors. For papillary carcinoma, the patients over 40 years of age comprised 50%. The typing of benign and malignant tumors is discussed. It is proposed that the occult cancer be classified according to histomorphology. Calcitonin by immunohistochemical technic or neural secretory granules by electron microscopy gives the most reliable evidence to diagnosis of the medullary carcinoma.

[Clinicopathologic study of 374 cases of intracranial tumors]

In this paper, 374 cases of intracranial tumor were studied retrospectively. The incidence of glioma (45.6%) was the highest, next was meningioma (19%) and pituitary tumor (12.3%). Astrocytoma comprised 73.5% of glioma. 75% of medulloblastoma and 54% of ependymoma occurred under 20 years of age, whereas 71.8% of meningioma, 44% of astrocytoma and 47.4% of metastatic tumor occurred between 21 to 50. The ratio of male and female was 1.69:1 except 0.8:1 of meningioma. 73.8% of all the lesions was located above the tentorium of cerebellum, the rest under it. Ninety one cases were followed. The 5 year survival rate was 25.3% (23/91). According to Kernohan's classification, the authors believe that astrocytoma can be divided into four grades, which is of great use in clinical diagnosis and prognosis. The other gliomas are only divided into benign and malignant. The results of surgery are related to tumor type and differentiation. Pituitary adenoma, meningioma, neurilemmoma and astrocytoma grades I and II have a good result by operation, while medulloblastoma, astrocytoma grades III and IV and metastatic cancer have a higher mortality.

[Pathomorphologic observation and prognostic analysis of 26 cases of malignant melanoma]

In this paper, 26 cases of malignant melanoma (MM) were analysed as to 10 items of clinicopathology, and 13 cases were followed. MM frequently occurs in the lower limbs. The peak age was 41 approximately 60 years. There was a history of having a black nevus (30.8%) and evident trauma (37.5%). Black nevus, located in the sole or palm, was able to undergo malignant change through long-term friction, irritation and so on. Therefore, preventive resection is necessary. Basing on the follow up study of 13 cases, three problems related to survival time are discussed: (1) Location of the tumor: MM in the mucosa has a worse prognosis than in the cutis. It might be considered as the rich blood supply to the mucosal tissue, easily resulting in hematogenous metastasis. (2) Clinical stage of the disease: The more advanced clinical stage, the shorter survival time. Early diagnosis and timely treatment play a key role in the prognosis. (3) TREATMENT: It is believed that extensive resection of the primary focus with dissection of the regional lymph nodes followed by adjuvant chemotherapy or Chinese traditional medicine is required. Correct diagnosis relies on the compositive analysis of 3 kinds of stain (iron reaction, fader and silver stain). The reticulum stain might be of benefit in differentiating the benign from malignant tumors. Diagnosis for the colorless MM depends on the finding of premelanin corpuscles by electronmicroscopy. In addition to Zhu Yuede's 9 criteria of diagnosis for MM, the authors propose that 4 features of MM in histostructure and cytomorphology be adhered to.