Tumor-specific targeting of polymer drug delivery systems with recombinant proteins bound via tris(nitrilotriacetic acid)

Antibody-mediated targeting is an efficient strategy to enhance the specificity and selectivity of polymer nanomedicines towards the target site, typically a tumor. However, direct covalent coupling of an antibody with a polymer usually results in a partial damage of the antibody binding site accompanied with a compromised biological activity. Here, an original solution based on well-defined non-covalent interactions between tris-nitrilotriacetic acid (trisNTA) and hexahistidine (His-tag) groups, purposefully introduced to the structure of each macromolecule, is described. Specifically, trisNTA groups were attached along the chains of a hydrophilic statistical copolymer based on N-(2-hydroxypropyl)methacrylamide (HPMA), and at the end or along the chains of thermo-responsive di-block copolymers based on N-isopropylmethacrylamide (NIPMAM) and HPMA; His-tag was incorporated to the structure of a recombinant single chain fragment of an anti-GD2 monoclonal antibody (scFv-GD2). Static and dynamic light scattering analyses confirmed that mixing of polymer with scFv-GD2 led to the formation of polymer/scFv-GD2 complexes; those prepared from thermo-responsive polymers formed stable micelles at 37 °C. Flow cytometry and fluorescence microscopy clearly demonstrated antigen-specific binding of the prepared complexes to GD2 positive murine T-cell lymphoma cells EL-4 and human neuroblastoma cells UKF-NB3, while no interaction with GD2 negative murine fibroblast cells NIH-3T3 was observed. These non-covalent polymer protein complexes represent a new generation of highly specific actively targeted polymer therapeutics or diagnostics.

Low levels of vitamin D in population exposed to significant environmental pollution

In recent years, monitoring of vitamin D levels and possible use of supplementation is gaining attention. Numerous studies showed low levels of vitamin D in winter months followed by improvement during summer. These changes are mostly dependent on the level of sun exposure, but also on geographical location, genetic factors, social-economic status, quality of nutrition and environmental pollution. In this observation we found significant decrease in vitamin D levels in populations exposed to extreme environmental pollution in area of central Europe. This region is known for extreme burden from microparticles originating in chemical industry, surface coal mining and cold-based power stations. Vitamin D levels in all patients was determined by ELISA. Using 540 patients in our department of clinical immunology and allergology we measured the levels of vitamin D in 2016 to 2021 period. In only 4 patients (0.74 %) we found vitamin D levels higher than 30 ng/ml. The curve of observed values does not reflect dependency on sun exposure and does not change during the year. We discuss the effect of environmental contaminants, lifestyle and economic and social factors. From our observations, we propose to directly supplement population with vitamin D, particularly children and seniors. From our observations, we propose to directly supplement population with vitamin D, particularly children and seniors.

Factors, associated with elevated concentration of soluble carbonic anhydrase IX in plasma of women with cervical dysplasia

Precancerous lesions of human cervix uteri have a tendency for regression or progression. In cervical intraepithelial neoplasia grade 2 (CINII) case there is an uncertainty if a lesion will progress or regress. The carbonic anhydrase IX (CAIX) enzyme is overexpressed in cervical cancer which is more sensitive to radiotherapy. CAIX is associated with poor prognosis in solid hypoxic tumors. The aim of this study was to determine factors related to elevated soluble CAIX (s-CAIX) in high-grade intraepithelial lesion (HSIL) cases. Methods. Patients diagnosed with HSIL (N = 77) were included into the research group whereas without HSIL (N = 72)—the control group. Concentration of the soluble CAIX (s-CAIX) in plasma was determined by the DIANA ligand-antibody-based method. C. trachomatis was detected from cervical samples by PCR. Primary outcomes were risk factors elevating s-CAIX level in HSIL group. Non-parametric statistical analysis methods were used to calculate correlations. Results. The s-CAIX level in patients with HSIL was elevated among older participants (r_s = 0.27, p = 0.04) and with C. trachomatis infection (p = 0.028). Among heavy smokers with HSIL, the concentration of s-CAIX was higher in older women (r_s = 0.52, p = 0.005), but was not related to the age of heavy smokers’ controls (τ = 0.18 p = 0.40). Conclusion. The concentration of s-CAIX was higher among older, heavy smoking and diagnosed with C. trachomatis patients. All these factors increased the risk for HSIL progression.

Tumor Marker B7-H6 Bound to the Coiled Coil Peptide-Polymer Conjugate Enables Targeted Therapy by Activating Human Natural Killer Cells

Targeted cancer immunotherapy is a promising tool for restoring immune surveillance and eradicating cancer cells. Hydrophilic polymers modified with coiled coil peptide tags can be used as universal carriers designed for cell-specific delivery of such biologically active proteins. Here, we describe the preparation of pHPMA-based copolymer conjugated with immunologically active protein B7-H6 via complementary coiled coil VAALEKE (peptide E) and VAALKEK (peptide K) sequences. Receptor B7-H6 was described as a binding partner of NKp30, and its expression has been proven for various tumor cell lines. The binding of B7-H6 to NKp30 activates NK cells and results in Fas ligand or granzyme-mediated apoptosis of target tumor cells. In this work, we optimized the expression of coiled coil tagged B7-H6, its ability to bind activating receptor NKp30 has been confirmed by isothermal titration calorimetry, and the binding stoichiometry of prepared chimeric biopolymer has been characterized by analytical ultracentrifugation. Furthermore, this coiled coil B7-H6-loaded polymer conjugate activates NK cells in vitro and, in combination with coiled coil scFv, enables their targeting towards a model tumor cell line. Prepared chimeric biopolymer represents a promising precursor for targeted cancer immunotherapy by activating the cytotoxic activity of natural killer cells.

Inhibitors of CA IX Enzyme Based on Polyhedral Boron Compounds

This review describes recent progress in the design and development of inhibitors of human carbonic anhydrase IX (CA IX) based on space-filling carborane and cobalt bis(dicarbollide) clusters. CA IX enzyme is known to play a crucial role in cancer cell proliferation and metastases. The new class of potent and selective CA IX inhibitors combines the structural motif of a bulky inorganic cluster with an alkylsulfamido or alkylsulfonamido anchor group for Zn²⁺ ion in the enzyme active site. Detailed structure-activity relationship (SAR) studies of a large series containing 50 compounds uncovered structural features of the cluster-containing inhibitors that are important for efficient and selective inhibition of CA IX activity. Preclinical evaluation of selected compounds revealed low toxicity, favorable pharmacokinetics and ability to reduce tumor growth. Cluster-containing inhibitors of CA IX can thus be considered as promising candidates for drug development and/or for combination therapy in boron neutron capture therapy (BNCT).

The structural basis for the selectivity of sulfonamido dicarbaboranes toward cancer-associated carbonic anhydrase IX

Human carbonic anhydrase IX (CA IX), a protein specifically expressed on the surface of solid tumour cells, represents a validated target both for anticancer therapy and diagnostics. We recently identified sulfonamide dicarbaboranes as promising inhibitors of CA IX with favourable activities both in vitro and in vivo. To explain their selectivity and potency, we performed detailed X-ray structural analysis of their interactions within the active sites of CA IX and CA II. Series of compounds bearing various aliphatic linkers between the dicarbaborane cluster and sulfonamide group were examined. Preferential binding towards the hydrophobic part of the active site cavity was observed. Selectivity towards CA IX lies in the shape complementarity of the dicarbaborane cluster with a specific CA IX hydrophobic patch containing V131 residue. The bulky side chain of F131 residue in CA II alters the shape of the catalytic cavity, disrupting favourable interactions of the spherical dicarbaborane cluster.

Study of family clusters of COVID-19 in the Ústí nad Labem Region with a focus on children - clinical picture, secondary transmission, antibody response

OBJECTIVE

The article presents the results of a study of family clusters of COVID-19 whose aim was to describe the clinical course of the disease in children, to identify secondary transmission in households with infected children, and to find out the differences in the antibody response between children and adults. Data were collected from 3 March 2020 to 25 October 2020, that is at the time when the alpha or delta variants were not dominant.

METHODS

A retrospective analysis of data on infected children in the Ústí nad Labem Region collected by the Regional Public Health Authority along with questionnaire data reported by their families. Serological tests were performed in study volunteers.

RESULTS

The most common symptoms in children were headache, runny nose, and loss of smell and taste. The hospital admission rates were 0.8% in children and 2.4% in adults. The secondary transmission rate in families where the index case was a child reached 22.6%. It was higher when the index case was a child 11-15 years of age or asymptomatic. The secondary transmission rate in families where the index case was an adult equalled 77.1%. Children had higher IgG antibody levels than adults at post-infection months 4 and 5, but their seropositivity rate was comparable to that of adults.

CONCLUSION

Children have a nonspecific clinical course of the disease, which is quite similar as other viroses, and rarely require hospital admission. Secondary transmission in families where the index case was a child is not uncommon and is also possible through contact with an asymptomatic child. After recovery, children have higher levels of antibodies at post-infection months 4 and 5.

Cobalt Bis(dicarbollide) Alkylsulfonamides: Potent and Highly Selective Inhibitors of Tumor Specific Carbonic Anhydrase IX

Invited for this month's cover is a collaboration from three institutes from the Czech Academy of Sciences: Institute of Inorganic Chemistry, Institute of Organic Chemistry and Biochemistry, and Institute of Molecular Genetics, and the University of Pardubice. The cover picture shows a family of potent and selective CA IX inhibitors that combines the structural motif of a bulky inorganic cobalt bis(dicarbollide) polyhedral ion with a propylsulfonamido anchor group. Read the full text of the article at 10.1002/cplu.202000574.

Functionalized hydrogel microparticles prepared by microfluidics and their interaction with tumour marker carbonic anhydrase IX

Microfluidics allows precise control of the synthesis of microparticles for specific applications, where size and morphology play an important role. In this work, we have introduced microfluidic chip design with dedicated extraction and gelation sections allowing to prepare hydrogel particles in the size range of a red blood cell. The influence of the extractive channel size, alginate concentration and type of storage media on the final size of the prepared alginate microparticles has been discussed. The second part of the work is dedicated to the surface modification of prepared particles using chitosan, pHPMA and the monoclonal antibody molecule, IgG M75. The specific interaction of the antibody molecule with an antigen domain of carbonic anhydrase IX, the transmembrane tumour protein associated with several types of cancer, is demonstrated by fluorescence imaging and compared to an isotypic antibody molecule.

Cobalt Bis(dicarbollide) Alkylsulfonamides: Potent and Highly Selective Inhibitors of Tumor Specific Carbonic Anhydrase IX

Carbonic anhydrase IX (CAIX) is an enzyme expressed on the surface of cells in hypoxic tumors. It plays a role in regulation of tumor pH and promotes thus tumor cell survival and occurrence of metastases. Here, derivatives of the cobalt bis(dicarbollide)(1-) anion are reported that are based on substitution at the carbon sites of the polyhedra by two alkylsulfonamide groups differing in the length of the aliphatic connector (from C1 to C4, n=1-4), which were prepared by cobalt insertion into the 7-sulfonamidoalkyl-7,8-dicarba-nido-undecaborate ions. Pure meso- and rac-diastereoisomeric forms were isolated. The series is complemented with monosubstituted species (n=2). Synthesis by a direct method furnished similar derivatives (n=2, 3), which are chlorinated at the B(8,8') boron sites. All compounds inhibited CAIX with subnanomolar inhibition constants and showed high selectivity for CAIX. The best inhibitory properties were observed for the compound with n= 3 and two substituents present in rac-arrangement with K_i =20 pM and a selectivity index of 668. X-ray crystallography was used to study interactions of these compounds with the active site of CAIX on the structural level.

Identification of Novel Carbonic Anhydrase IX Inhibitors Using High-Throughput Screening of Pooled Compound Libraries by DNA-Linked Inhibitor Antibody Assay (DIANA)

The DNA-linked inhibitor antibody assay (DIANA) has been recently validated for ultrasensitive enzyme detection and for quantitative evaluation of enzyme inhibitor potency. Here we present its adaptation for high-throughput screening of human carbonic anhydrase IX (CAIX), a promising drug and diagnostic target. We tested DIANA's performance by screening a unique compound collection of 2816 compounds consisting of lead-like small molecules synthesized at the Institute of Organic Chemistry and Biochemistry (IOCB) Prague ("IOCB library"). Additionally, to test the robustness of the assay and its potential for upscaling, we screened a pooled version of the IOCB library. The results from the pooled screening were in agreement with the initial nonpooled screen with no lost hits and no false positives, which shows DIANA's potential to screen more than 100,000 compounds per day.All DIANA screens showed a high signal-to-noise ratio with a Z' factor of >0.89. The DIANA screen identified 13 compounds with K_i values equal to or better than 10 µM. All retested hits were active also in an orthogonal enzymatic assay showing zero false positives. However, further biophysical validation of identified hits revealed that the inhibition activity of several hits was caused by a single highly potent CAIX inhibitor, being present as a minor impurity. This finding eventually led us to the identification of three novel CAIX inhibitors from the screen. We confirmed the validity of these compounds by elucidating their mode of binding into the CAIX active site by x-ray crystallography.

The duration of SARS-CoV-2 shedding in patients recovering from COVID-19

The knowledge of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) shedding is highly relevant to the diagnosis, treatment and follow-up of patients with COVID-19 (coronavirus disease 2019). Deep nasopharyngeal swabs repeatedly collected from a cohort of one hundred patients with COVID-19 were tested for SARS-CoV-2 RNA using RT-PCR (real-time polymerase chain reaction). The median period of viral genome detectability was 15 days. Furthermore, the authors tested the hypothesis on the relationship between the severity of COVID-19 and the period in which the viral genome is detectable. They did not find any statistically significant difference in the duration of viral clearance between patients with asymptomatic to mild disease or severe disease.

Metallacarborane Sulfamides: Unconventional, Specific, and Highly Selective Inhibitors of Carbonic Anhydrase IX

Carbonic anhydrase IX (CAIX) is a transmembrane enzyme that regulates pH in hypoxic tumors and promotes tumor cell survival. Its expression is associated with the occurrence of metastases and poor prognosis. Here, we present nine derivatives of the cobalt bis(dicarbollide)(1-) anion substituted at the boron or carbon sites by alkysulfamide group(s) as highly specific and selective inhibitors of CAIX. Interactions of these compounds with the active site of CAIX were explored on the atomic level using protein crystallography. Two selected derivatives display subnanomolar or picomolar inhibition constants and high selectivity for the tumor-specific CAIX over cytosolic isoform CAII. Both derivatives had a time-dependent effect on the growth of multicellular spheroids of HT-29 and HCT116 colorectal cancer cells, facilitated penetration and/or accumulation of doxorubicin into spheroids, and displayed low toxicity and showed promising pharmacokinetics and a significant inhibitory effect on tumor growth in syngenic breast 4T1 and colorectal HT-29 cancer xenotransplants.

Microgel Bioreactors for Cancer Cell Targeting by pH-Dependent Generation of Radicals

The lack of specificity of traditional cytostatics and increasing resistance of cancer cells represent important challenges in cancer therapy. One of the characteristics of cancer cells is their intrinsic oxidative stress caused by higher metabolic activity, mitochondrial malfunction, and oncogene stimulation. This feature can be exploited in the pursuit of more selective cancer therapy, as there is increasing evidence that cancer cells are more sensitive to elevated concentrations of reactive oxygen species than normal cells. In this study, we demonstrate a new concept for cancer cell targeting by in situ production of radicals under physiological conditions. The biologically active radicals are produced in the milieu of cancer cells by enzymatic conversion from an inactive precursor, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt, by using miniature bioreactors represented by cell-sized microgels containing immobilized laccase. We utilize the pH-dependent activity of laccase to generate radicals only at a lower pH (5.7-6.1) that is characteristic of the tumor microenvironment. The composition of the microgels was optimized so as to allow sufficient substrate and radical diffusion, high enzyme activity, and stability under physiological conditions. The functionality of this system was evaluated on three cancer cell lines (HeLa, HT-29, and DLD1) and the cytotoxicity of in situ-produced radicals was successfully proven in all cases. These results demonstrate that cancer cell targeting by in situ-generated radicals using miniature enzymatic reactors may represent an alternative to traditional cytostatics. In particular, the pH-dependence of radical generation and their short-lived nature can ensure localized functionality in the tumor microenvironment and thereby reduce systemic side-effects.

Fluorescent Probes for Monitoring Cholesterol Trafficking in Cells

Cellular cholesterol plays fundamental and diverse roles in many biological processes and affects the pathology of various diseases. Comprehensive and detailed understanding of the cellular functions and characteristics of cholesterol requires visualization of its subcellular distribution, which can be achieved by fluorescence microscopy. Many attempts have been made to develop fluorescent cholesterol reporters, but so far, none of them seems to be ideal for studying all aspects of cholesterol management. To meet the requirements for the right probe remains a great challenge, and progress in this field continues. The main objective of this review is to not only present the current state of the art, but also critically evaluate the applicability of individual probes and for what purpose they can be used to obtain relevant data. Hence, the data obtained with different probes might provide complementary information to build an integrated picture about the cellular cholesterol.

Polymer Cancerostatics Targeted by Recombinant Antibody Fragments to GD2-Positive Tumor Cells

A water-soluble polymer cancerostatic actively targeted against cancer cells expressing a disialoganglioside antigen GD2 was designed, synthesized and characterized. A polymer conjugate of an antitumor drug doxorubicin with a N-(2-hydroxypropyl)methacrylamide-based copolymer was specifically targeted against GD2 antigen-positive tumor cells using a recombinant single chain fragment (scFv) of an anti-GD2 monoclonal antibody. The targeting protein ligand was attached to the polymer-drug conjugate either via a covalent bond between the amino groups of the protein using a traditional nonspecific aminolytic reaction with a reactive polymer precursor or via a noncovalent but highly specific interaction between bungarotoxin covalently linked to the polymer and the recombinant scFv modified with a C-terminal bungarotoxin-binding peptide. The GD2 antigen binding activity and GD2-specific cytotoxicity of the targeted noncovalent polymer-scFv complex proved to be superior to the covalent polymer-scFv conjugate.

A new approach to CAR T-cell gene engineering and cultivation using piggyBac transposon in the presence of IL-4, IL-7 and IL-21

BACKGROUND AIMS

Clinical-grade chimeric antigenic receptor (CAR)19 T cells are routinely manufactured by lentiviral/retroviral (LV/RV) transduction of an anti-CD3/CD28 activated T cells, which are then propagated in a culture medium supplemented with interleukin (IL)-2. The use of LV/RVs for T-cell modification represents a manufacturing challenge due to the complexity of the transduction approach and the necessity of thorough quality control.

METHODS

We present here a significantly improved protocol for CAR19 T-cell manufacture that is based on the electroporation of peripheral blood mononuclear cells with plasmid DNA encoding the piggyBac transposon/transposase vectors and their cultivation in the presence of cytokines IL-4, IL-7 and IL-21.

RESULTS

We found that activation of the CAR receptor by either its cognate ligand (i.e., CD19 expressed on the surface of B cells) or anti-CAR antibody, followed by cultivation in the presence of cytokines IL-4 and IL-7, enables strong and highly selective expansion of functional CAR19 T cells, resulting in >90% CAR⁺ T cells. Addition of cytokine IL-21 to the mixture of IL-4 and IL-7 supported development of immature CAR19 T cells with central memory and stem cell memory phenotypes and expressing very low amounts of inhibitory receptors PD-1, LAG-3 and TIM-3.

CONCLUSIONS

Our protocol provides a simple and cost-effective method for engineering high-quality T cells for adoptive therapies.

Antibody-pHPMA functionalised fluorescent silica nanoparticles for colorectal carcinoma targeting

Nanoparticles functionalised with pHPMA and monoclonal antibody IgG M75 show specific adhesion to tumour cells expressing carbonic anhydrase IX bothin vitroandin vivo.

In vitro evaluation of the monoclonal antibody 64Cu-IgG M75 against human carbonic anhydrase IX and its in vivo imaging

Specific oncology diagnostics requires new types of the selective radiopharmaceuticals, particularly those suitable for the molecular PET imaging. The aim of this work is to present a new, specific PET-immunodiagnostic radiopharmaceutical based on the monoclonal antibody IgG M75 targeting human carbonic anhydrase IX labelled with ⁶⁴Cu (T_½ = 12.70h) and its in vitro and in vivo evaluation. The antibody IgG M75 was conjugated with a non-commercial copper-specific chelator "phosphinate" and then labelled with the positron emitter ⁶⁴Cu. Stability of the labelled conjugated was tested in human serum. The immunoreactivity of the labelled conjugate was evaluated in vitro on a suitable cell cultures of the colorectal carcinoma (HT-29) and its imaging properties were estimated in vivo on a mouse model with inoculated colorectal carcinoma HT-29 imaged on a µPET/CT. The tested radioimmunoconjugate was obtained in a specific activity of 0.25-0.5 MBq/µg. In vitro uptake experiments revealed specific binding to the HT-29 cells (45 ± 2.8% of the total added activity) and the measured K_D value was found to be 9.2nM. Imaging clearly demonstrated significant uptake of the labelled monoclonal antibody in the tumour at 18h post administration. The radioimmunoconjugate ⁶⁴Cu-PS-IgG M75 seems to be a suitable candidate for PET diagnostics of hypoxic tumours expressing human carbonic anhydrase IX.

IgG-4 related disease in ophthalmology

IgG-4 related disease (IgG4-RD) is a recently discovered systemic fibro-inflammatory disease which affects the ocular system. This pathology is not limited only to the orbit, but may also frequently affect the anatomical structures of the eye, as well as other organs. Suspicion of IgG4-RD is based on careful clinical, radiological and immuno-histological examination with a finding of characteristic histopathological changes. Increased values of serum IgG4 need not necessarily be an unequivocal diagnostic criterion for the diagnosis of IgG4-RD. Only a careful histological and immunophenotyping examination together with a clinical finding provide a basis for distinguishing IgG4-RD from other inflammatory pathologies. Corticoids are applied in the treatment of this disease, but they do not exclude the possibility of relapses of clinical manifestations. Second choice pharmaceuticals are azathioprine, mycophenolate mofetil, and the effect of treating relapse of the disease with rituximab is significant.Key words: IgG4 related disease, eye, diagnosis, treatment.

Synthesis and deposition of a Tröger’s base polymer on the electrode surface for potentiometric detection of a neuroblastoma tumor marker metabolite

We propose an innovative approach to detect a low molecular weight metabolite of neuroblastoma.

Lenalidomide enhances antitumor functions of chimeric antigen receptor modified T cells

Tumor immunotherapy based on the use of chimeric antigen receptor modified T cells (CAR T cells) is a promising approach for the treatment of refractory hematological malignancies. However, a robust response mediated by CAR T cells is observed only in a minority of patients and the expansion and persistence of CAR T cells in vivo is mostly unpredictable.Lenalidomide (LEN) is an immunomodulatory drug currently approved for the treatment of multiple myeloma (MM) and mantle cell lymphoma, while it is clinically tested in the therapy of diffuse large B-cell lymphoma of activated B cell immunophenotype. LEN was shown to increase antitumor immune responses at least partially by modulating the activity of E3 ubiquitin ligase Cereblon, which leads to increased ubiquitinylation of Ikaros and Aiolos transcription factors, which in turn results in changed expression of various receptors on the surface of tumor cells. In order to enhance the effectiveness of CAR-based immunotherapy, we assessed the anti-lymphoma efficacy of LEN in combination with CAR19 T cells or CAR20 T cells in vitro and in vivo using various murine models of aggressive B-cell non-Hodgkin lymphomas (B-NHL).Immunodeficient NSG mice were transplanted with various human B-NHL cells followed by treatment with CAR19 or CAR20 T cells with or without LEN. Next, CAR19 T cells were subjected to series of tests in vitro to evaluate their response and signaling capacity following recognition of B cell in the presence or absence of LEN.Our data shows that LEN significantly enhances antitumor functions of CAR19 and CAR20 T cells in vivo. Additionally, it enhances production of interferon gamma by CAR19 T cells and augments cell signaling via CAR19 protein in T cells in vitro. Our data further suggests that LEN works through direct effects on T cells but not on B-NHL cells. The biochemical events underlying this costimulatory effect of LEN are currently being investigated. In summary, our data supports the use of LEN for augmentation of CAR-based immunotherapy in the clinical grounds.

Clinical significance of anti-C1q antibodies in SLE

Lupus nephritis (LN) is a severe and frequent complication of systemic lupus erythematosus (SLE). Untreated cases very often lead to patients’ death; therefore, it is important to use markers sensitive and specific enough for the diagnosis and subsequent monitoring of nephritis. Autoantibodies against double-stranded DNA (anti-dsDNA) are believed to play a major role in SLE in general and so their significance in prediction and monitoring of glomerular inflammation is low. For prediction of renal flares and effective, well-timed therapy, it is required to have an appropriate marker available. In our study, we have tested sera of 85 SLE patients with or without LN. The criterion for LN determination was the degree of proteinuria (persistent proteinuria > 0.5 g/day, according to ACR criteria for LN). Disease activity was described by SLE disease index (SLEDAI) score, renal functions were stated according to British Isles Lupus Assessment Group score. There were anti-C1q, total anti-dsDNA and high-avidity anti-dsDNA detected in the patients’ sera. We did not find any significant difference in average SLEDAI value between patients with renal and non-renal organ complications. Positivity of anti-C1q was more frequent in patients with nephritis than in those without any history of renal disease (58.3 vs. 39.1%). Higher prevalence of these antibodies was evident in patients with clinically active LN than in those without renal improvement (73.1 vs. 39.1%). When comparing anti-C1q with antibodies against structures of DNA, significant differences were found in case of high avidity anti-dsDNA. Our results have confirmed the studies showing that anti-C1q antibodies could serve as a reliable serological marker of LN activity along with other laboratory tests. Detection of anti-C1q together with high avidity anti-dsDNA antibodies seems to be a good algorithm for the prediction of possible renal flares in SLE patients.

β-glucan affects mucosal immunity in children with chronic respiratory problems under physical stress: clinical trials

BACKGROUND

The role of β-glucan in children with respiratory problems is getting more and more attention. In this report we focused on the effects of 30 days oral supplementation with β-glucan on physical activity and immune status of children with respiratory problems.

METHODS

We measured the level of sIgA, eNO and physical activity [using a 6-minute walking test (6MWT)] in 77 children and evaluated the effect of 100 mg/day oral dose.

RESULTS

We found a significant difference between males and females in physical endurance. In the glucan group, the positive effects of glucan were significant in both age groups. In the glucan group, we found significant decrease of eNO levels and stabilization of the sIgA levels.

CONCLUSIONS

Short-term oral application of natural immunomodulator β-glucan stimulated physical endurance in children with respiratory problems and, via stabilization of the sIgA levels, helps their mucosal immunity.

Striking antitumor activity of a methinium system with incorporated quinoxaline unit obtained by spontaneous cyclization

A novel pentamethinium salt was synthesized with an unforeseen expanded conjugated quinoxaline unit directly incorporated into a pentamethinium chain. The compound exhibited high fluorescence intensity, selective mitochondrial localization, high cytotoxicity, and selectivity toward malignant cell lines, and resulted in remarkable in vivo suppression of tumor growth in mice.

Optimization of the crystallizability of a single-chain antibody fragment

Single-chain variable antibody fragments (scFvs) are molecules with immense therapeutic and diagnostic potential. Knowledge of their three-dimensional structure is important for understanding their antigen-binding mode as well as for protein-engineering approaches such as antibody humanization. A major obstacle to the crystallization of single-chain variable antibody fragments is their relatively poor homogeneity caused by spontaneous oligomerization. A new approach to optimization of the crystallizability of single-chain variable antibody fragments is demonstrated using a representative single-chain variable fragment derived from the anti-CD3 antibody MEM-57. A Thermofluor-based assay was utilized to screen for optimal conditions for antibody-fragment stability and homogeneity. Such an optimization of the protein storage buffer led to a significantly improved ability of the scFv MEM-57 to yield crystals.

Clinical trials of yeast-derived β-(1,3) glucan in children: effects on innate immunity

BACKGROUND

The role of glucan in the stimulation of immune reactions is well established. In our report, we focused on the effects of orally administered glucan on nonspecific immunity of children with chronic respiratory problems.

MATERIALS AND METHODS

We measured the levels of albumin, lysozyme. C-reactive protein (CRP) and calprotectin in the saliva of 60 children ages 8-12 years and evaluated the effects of 30-day treatment with 100 mg/d oral dose of glucan.

RESULTS

We found a significant increase in the production of lysozyme, CRP and calprotectin in glucan-treated children.

CONCLUSIONS

Short-term oral application of natural immunomodulator β-glucan significantly stimulated mucosal immunity of children with chronic respiratory problems.

Placebo-driven clinical trials of yeast-derived β-(1-3) glucan in children with chronic respiratory problems

BACKGROUND

The role of glucan in stimulation of immune reactions has been studied for several decades. In this report we focused on the effects of orally administered glucan in children with chronic respiratory problems.

MATERIALS AND METHODS

We measured the levels of albumin, lysozyme and CRP in saliva of 40 children aged 8-12 years and evaluate the effects of 100 mg/d oral dose of glucan.

RESULTS

We found a significant increase in production of changes in production of lysozyme and CRP in glucan-treated children. In addition, a strong improvement in general conditions was found.

CONCLUSIONS

Short-term oral application of natural immunomodulator β-glucan stimulated mucosal immunity of children with chronic respiratory problems.

Feasibility and constraints of particle targeting using the antigen-antibody interaction

This work is concerned with the surface modification of fluorescent silica nanoparticles by a monoclonal antibody (M75) and the specific bioadhesion of such particles to surfaces containing the PG domain of carbonic anhydrase IX (CA IX), which is a trans-membrane protein specifically expressed on the surfaces of several tumor cell lines. The adhesion strength of antibody-bearing silica nanoparticles to antigen-bearing surfaces was investigated under laminar flow conditions in a microfluidic cell and compared to the adhesion of unmodified silica nanoparticles and nanoparticles coupled with an unspecific antibody. Adhesion to cancer cells using flow cytometry was also investigated and in all cases the adhesion strength of M75-modified nanoparticles was significantly stronger than for the unmodified or unspecific nanoparticles, up to several orders of magnitude in some cases. The specific modification of nano- and microparticles by an antibody-like protein therefore appears to be a feasible approach for the targeting of tumor cells.

[Diagnosis of whooping cough by serology and real-time PCR]

The goal of this study is to summarize the results of the detection of Bordetella pertussis (BP) and Bordetella parapertussis (BPP) by a real-time polymerase chain reaction (RT-PCR) assay and serological methods. In 2008-2010, 73 patients of the Department of Clinical Immunology and Allergology of the Centre for Immunology and Microbiology, Public Health Institute in Ústí nad Labem were screened for pertussis. They were selected according to the WHO and ECDC criteria, i. e. they presented with a persistent cough lasting more than two weeks. Direct detection of BP and BPP DNA from nasopharyngeal wash specimens was performed using a RT PCR assay. The serological responses were evaluated by a direct agglutination test for the detection of total antibodies and by enzyme-linked immunosobent assay (ELISA) for the detection of IgG, IgA, and IgM antibodies against pertussis toxin. Forty-two patients were positive for BP and/or BPP, 19 of them by RT-PCR (group A) and 23 by serology (group B). Ten group A patients (52.6%) were also positive by serology. Our results show that pertussis needs to be a consideration in persistent cough. We believe that increased awareness of the medical community, along with improved laboratory tests will result in increased detection of pertussis that is still considered by many physicians as a childhood infection.

Avidin-conjugated polymers with monobiotinylated antibody fragments: A new strategy for the noncovalent attachment of recombinant proteins for polymer therapeutics

The high affinity and specificity between avidin and biotin were employed to bind a recombinant single-chain antibody fragment to synthetic hydrophilic polymer drug carriers. Two semitelechelic polymers, based on poly(ethylene glycol) and poly[ N-(2-hydroxypropyl)methacrylamide], each containing a single thiol end group, were conjugated to dithiopyridyl-modified avidin. The biotinylated recombinant single-chain antibody fragment of the M75 antibody was then noncovalently bound to the polymer-avidin conjugates. The recombinant protein was chosen as a targeting ligand against carbonic anhydrase IX, a marker overexpressed by tumor cells of various human carcinomas. The antigen-binding affinity of the polymer–single-chain antibody fragment complex was confirmed by enzyme-linked immuno sorbent assay (ELISA). This approach provides an original, nondestructive way of preparing supramolecular systems intended for targeted delivery of therapeutics utilizing modern chemical procedures, including reversible addition–fragmentation chain-transfer polymerization and recombinant DNA techniques.

[Esophageal replacement using large intestine--experience with 109 cases]

Use of large intestinal transplants in esophageal replacement is an uncommonly used alternative. The authors discuss its indications in benign, as well as in malignant disorders and, based on them, assign them into three groups. Based on historical data and their professional experience, they present reasons for the commonest uses of particular parts of the large intestine. They evaluate introperative, as well as long-term outcomes.

[Video-assisted esophageal resection for carcinoma--ten-year experience]

INTRODUCTION

Esophageal procedures belong to the most complicated gastrointestinal procedures. Therefore, esophageal carcinoma patients have been and still are concentrated into specialized centres, equipped with all diagnostic and therapeutic means. At the Ist Surgical Clinic of the LF UP (Medical Faculty of the Palacky University) in Olomouc, esophageal surgery has a long lasting tradition. In the management of malignant esophageal disorders, the clinic prefers the use subtotal esophageal resection, attaching the esophagus transplant to a cervical esophageal stud, to the use of more saving resection with the anastomosis site in the mediastinum. In order to substitute for the resected esophagus, the authors normally use a tubulized gastric flap. In cases, where the stomach cannot be used, the authors use transverse colon to replace the resected esophagus. Classical esophageal procedures have nearly entirely been replaced by video-assisted procedures. Most esophageal resections are performed using video-assisted laparoscopic transhiatal approach. In the management of esophageal tumors which are located at the level of tracheal bifurcation, or below it, the authors use right- sided thoracoscopic approach.

MATERIAL AND METHODS

During the past 10 years, 178 patients have undergone subtotal esophageal resection for esophageal carcinoma. In 81 patients (45.5%), the esophagus was resected using classical approach. 35 subjects underwent transhiatal "blind"extirpation according to Orringer, in 46 subjects right-sided thoracotomy was used (subjects with tumors located in the middle third of the thoracic esophagus and higher). Video-assisted approach was used in 97 patients, which included 88 subjects with laparoscopic transhiatal modification of the procedure and 9 subjects, who underwent video-thoracoscopy.

OUTCOMES

The mean procedure duration was 242 minutes. The authors recorded the following complications: pneumothorax in 29 patients (16%) and n. laryngeus recurrens palsy in 16 subjects (9%). 13 patients (7%) developed a fistule in anastomosis, which was managed by drainage of the cervical wound. Pulmonary complications were recorded in 55 patients (31%). The mean duration of hospitalization was 12 days, intraoperative death rate was 4.5%. Only 2 out of 8 deaths occurring during the early postoperative period, were surgery-related. In the both cases, mediastinitis developed, resulting from a transponate necrosis in one of the cases and from a bronchial fistule in the other subject. Five subjects exited because of ARDS, which included one case of myocardial infarction.

CONCLUSION

When esophageal carcinoma is managed at a clinic equipped with the latest modern diagnostic and therapeutical means, the procedure of esophageal resection is a fairly safe procedure with low death and morbidity rates.

[Iatrogenic bile ducts injuries]

AIM

To evaluate therapeutic options and outcomes of repair of iatrogenic bile duct injuries during cholecystectomy, which were solved in our institution over the past five years. The incidence of this injury is stated in the range of 0-0.4% for open cholecystectomy and 0-0.7% for laparoscopic cholecystectomy.

METHODS

Authors present a group of ten patients who were operated on for iatrogenic bile duct injury incurred during cholecystectomy in 2005-2009. All patiens were refered from other hospitals. Three men and seven women aged 20-71 years. The bile duct injury occured twice during open procedure and during laparoscopic procedure in eight. Incomplete lesion was idenified in one case, complete lesions with tissue loss were found in nine patients. Right hepatic artery injuries were found in four patients with tissue loss injury. Nine patients required reconstruction of the biliary tract using hepaticojejunoanastomosis with Roux-Y loop.

RESULTS

The bile leak occurred in two patients after reconstruction. In one patient was required early percutaneous transhepatic drainage. The early death occurred in a patient with a complicated course, where our reconstruction of the biliary tract was already in the field of advanced biliary peritonitis as a third operation during 7 days. All other patients are monitored postoperatively at regular intervals in our clinic. They carried out clinical examinations and monitoring of liver enzymes. In the long interval from reconstruction (6-12 months) anastomotic stenosis occurred in three patients. Postoperative radiological intervention in the form of dilation of anastomosis and prolonged transient transanastomotic drainage was necessary (the duration of drainage was 6-7 months).

CONCLUSION

Iatrogenic bile duct injury is a serious condition threatening the patient's life from the progressive failure of liver function on the basis of secondary biliary cirrhosis. Due to the nature of lesions arising from laparoscopic cholecystectomy (loss tissue injuries, thermal damage to surrounding structures, the hepatic artery injuries) reconstructions are extremely difficult. For most patients reconstructive operations are the last possible surgical procedures in this area, except for liver transplantation. Hilar reconstructions have a higher probability of stenosis of the anastomosis. If they occur, there are repeated cholangitis, which pass into the secondary sclerosing cholangitis and cause secondary biliary cirrhosis, with all the consequences of disease (portal hypertension, bleeding esophageal varices). For these reasons, it is necessary for careful long-term postoperative monitoring of liver function and good interdisciplinary cooperation, especially with the intervention radiologist in management postoperatively evolving stenosis of anastomoses. It is necessary for the early identification and indication of radiological interventions in order to prevent damage to the liver parenchyma.

Mouse to human comparative genetics reveals a novel immunoglobulin E-controlling locus on Hsa8q12

Atopy is a predisposition to hyperproduction of immunoglobulin E (IgE) against common environmental allergens. It is often associated with development of allergic diseases such as asthma, rhinitis, and dermatitis. Production of IgE is influenced by genetic and environmental factors. In spite of progress in the study of heredity of atopy, the genetic mechanisms of IgE regulation have not yet been completely elucidated. The analysis of complex traits can benefit considerably from integration of human and mouse genetics. Previously, we mapped a mouse IgE-controlling locus Lmr9 on chromosome 4 to a segment of <9 Mb. In this study, we tested levels of total IgE and 25 specific IgEs against inhalant and food allergens in 67 Czech atopic families. In the position homologous to Lmr9 on chromosome 8q12 marked by D8S285, we demonstrated a novel human IgE-controlling locus exhibiting suggestive linkage to composite inhalant allergic sensitization (limit of detection, LOD = 2.11, P = 0.0009) and to nine specific IgEs, with maximum LOD (LOD = 2.42, P = 0.0004) to plantain. We also tested 16 markers at previously reported chromosomal regions of atopy. Linkage to plant allergens exceeding the LOD > 2.0 was detected at 5q33 (D5S1507, LOD = 2.11, P = 0.0009) and 13q14 (D13S165, LOD = 2.74, P = 0.0002). The significant association with plant allergens (quantitative and discrete traits) was found at 7p14 (D7S2250, corrected P = 0.026) and 12q13 (D12S1298, corrected P = 0.043). Thus, the finding of linkage on chromosome 8q12 shows precision and predictive power of mouse models in the investigation of complex traits in humans. Our results also confirm the role of loci at 5q33, 7p14, 12q14, and 13q13 in control of IgE.

[Analytical methods at the boundary between biochemistry and immunology]

The article presents assays shared by both disciplines; i.e the specialization 801 (Clinical Biochemistry) and 813 (Laboratory of Allergology and Immunology), and it covers over 60 tests. It is intended as reference information for general practitioners, as well as for laboratory workers at the beginning of their studies. Emphasis is laid on some facts which GPs ordering laboratory determinations should be familiar with; the pre-analytical stage (specimen collection, their transport and storage), the analytical reliability of particular methods, their accessibility, frequency and total costs. Analytical techniques are only mentioned marginally as their understanding is not essential for GPs. Assuming the readers' fundamental experience of diagnostic applications of the methods discussed; we only comment some obsolete or rare tests. The shared assays cover selected analyses of proteins (incl. some enzymes and tumormarkers), ions, osmolality and quantitative microscopic urinalysis.