Rabbit Polyclonal Antibody Research Articles

Histomorphometric changes in pituitary gonadotropic endocrinocytes when exposed to dark deprivation

Aim. To assess the effect of 30-day dark deprivation on functional and histomorphometric changes in adenohypophysis gonadotropic endocrinocytes and their reversibility in mature male rats.Materials and methods. Mongrel white male rats (n = 36) weighing 365–375 g at 4 months of age were randomly divided into three groups (each n = 12). For 30 days the control group was in automatic light-dark mode 12/12, and the rats of experimental groups 1 and 2 were in round-the-clock artificial lighting (24/0, 300 Lux), then the rats of group 2 were returned to 12/12 mode for the next 14 days. In the animals of the control and group 1 during their lifetime on the 31st day, and in group 2 on the 45th day, blood was taken from the abdominal aorta and levels of follicle-stimulating (FSH) and luteinizing (LH) hormones, melatonin, and Klotho protein were determined an enzyme-linked immunosorbent assay and immunoassay and after which they were removed from the experiment by decapitation. Postmortem histological and immunohistochemical examination of the pituitary gland was done using rabbit polyclonal antibodies targeting caspase-3 and Klotho protein, as well as morphometry. Statistical data processing was performed using the Kruskal-Wallis test with post-hoc Dunn’s test.Results. Light desynchronization in the form of 30 days of dark deprivation increased FSH and LH levels and decreased melatonin and Klotho protein levels in the blood of male rats; increased gonadotropic endocrine cell area, volume, and perimeter by 23.1% (p < 0.001), 48.7% (p < 0.001), and 10.9% (p < 0.001), respectively; and increased nucleus area, volume, and perimeter by 16%, 11.7%, and 2.5%, respectively. An immunohistochemical study showed an increase in the specific area of caspase-3-immunoreactive gonadotropic endocrinocytes by 25.2% without obvious morphological signs of apoptosis, and a decrease in the expression of Klotho protein by 25.7%. All indicators were reversible, the levels of FSH and Klotho protein in the blood of animals almost reached their initial values after 14 days of restoration of the light-dark cycle 12/12.Conclusion. Dark deprivation for 30 days in male rats induced reversible processes of accelerated aging and apoptosis in cells, as evidenced by changes in the expression of aging markers in gonadotropic endocrinocytes and levels of gonadotropic hormones in the blood. When the light-dark mode is restored, the levels of FSH and Klotho protein normalize as early as 14 days.

Comparison of Conjugates Obtained Using DMSO and DMF as Solvents in the Production of Polyclonal Antibodies and ELISA Development: A Case Study on Bisphenol A

When developing immunochemical test systems, it is necessary to obtain specific antibodies. Their quality depends, among other things, on the immunogen used. When preparing hapten–protein conjugates to obtain antibodies for low-molecular-weight compounds, the key factors are the structure of the hapten itself, the presence of a spacer, the size of the carrier protein and the degree of its modification by hapten molecules. This work shows that one additional factor—the conditions for obtaining the hapten–protein conjugate—is overlooked. In this work, we have synthesized conjugates of bisphenol A derivative 4,4-bis(hydroxyphenyl)valeric acid (BVA), the protein carrier soybean trypsin inhibitor (STI), and bovine serum albumin (BSA) in reaction media combining water with two organic solvents: dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). Namely, BSADMF–BVA, STIDMF–BVA, BSADMSO–BVA and STIDMSO–BVA conjugates were obtained. Rabbit polyclonal antibodies against the BSADMF–BVA conjugate demonstrated basically different interactions in the developed ELISA systems using either STIDMF–BVA or STIDMSO–BVA conjugates. The use of the STIDMF–BVA conjugate demonstrated the absence of competition in combination with antisera obtained from BSADMF–BVA in an ELISA. A competitive interaction was observed only with the use of the STIDMSO–BVA conjugate. Under the selected conditions, the detection limit of bisphenol A was 8.3 ng/mL, and the working range of determined concentrations was 18.5–290.3 ng/mL. The obtained data demonstrate the possibility of achieving sensitive immunoassays by simply varying the reaction media for the hapten–protein conjugation, which could provide an additional tool in the development of immunoassays for other low-molecular-weight compounds.

Optimizing antigen preparation for oxalyl-CoA decarboxylase enzyme diagnostic kit and ELISA system cutoff determination.

The prevalence of kidney stone disease is increasing globally, with calcium oxalate stones being the most common type. Oxalyl-CoA decarboxylase (OXC), an enzyme produced by the gut bacterium Oxalobacter formigenes, plays a crucial role in oxalate metabolism. Deficiencies in OXC activity can lead to the accumulation of oxalate, contributing to kidney stone formation. This study aimed to develop a reliable diagnostic assay for OXC by optimizing antigen production and establishing a cutoff value for an enzyme-linked immunosorbent assay (ELISA). We cloned, expressed, and purified recombinant OXC protein in Escherichia coli BL21(DE3), and generated specific polyclonal antibodies in rabbits. The ELISA system was optimized and validated using serum samples from 40 healthy individuals and 6 patients with oxalate-related disorders. The cutoff value was determined using the formula (M + 2SD), where (M) is the mean and (SD) is the standard deviation of the healthy sample results. The calculated cutoff value of 0.656750 effectively distinguished between healthy and affected individuals, with a sensitivity of 97.5% and a specificity of 83.3%. These findings provide a valuable tool for the early detection and management of oxalate-related disorders, with significant implications for clinical practice.

A novel double antibody sandwich quantitative ELISA for detecting porcine epidemic diarrhea virus infection.

Porcine epidemic diarrhea (PED), a contagious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV), has caused significant economic losses to the global pig farming industry due to its rapid course and spread and its high mortality among piglets. In this study, we prepared rabbit polyclonal antibody and monoclonal antibody 6C12 against the PEDV nucleocapsid (N) protein using the conserved and antigenic PEDV N protein as an immunogen. A double-antibody sandwich quantitative enzyme-linked immunosorbent assay (DAS-qELISA) was established to detect PEDV using rabbit polyclonal antibodies as capture antibodies and horseradish peroxidase (HRP)-labeled 6C12 as the detection antibody. Using DAS-qELISA, recombinant PEDV N protein, and virus titer detection limits were approximately 0.05 ng/mL and 103.02 50% tissue culture infective dose per mL (TCID50/mL), respectively. There was no cross-reactivity with porcine reproductive and respiratory syndrome virus (PRRSV), porcine rotavirus (PoRV), porcine pseudorabies virus (PRV), porcine deltacoronavirus (PDCoV), or porcine circovirus (PCV). The reproducibility of DAS-qELISA was verified, and the coefficient of variation (CV) for intra- and inter-batch replicates was less than 10%, indicating good reproducibility. When testing anal swab samples from PEDV-infected piglets using DAS-qELISA, the coincidence rate was 92.55% with a kappa value of 0.85 when using reverse transcription-polymerase chain reaction (RT-PCR) and 94.29% with a kappa value of 0.88 when using PEDV antigen detection test strips, demonstrating the reliability of the method. These findings provide fundamental material support for both fundamental and practical studies on PEDV and offer a crucial diagnostic tool for clinical applications. KEY POINTS: • A new anti-PEDV N protein monoclonal antibody strain was prepared • Establishment of a more sensitive double antibody sandwich quantitative ELISA • DAS-qELISA was found to be useful for controlling the PEDV spread.

Serotype 15C Streptococcus pneumoniae resistant to classical complement deposition and agglutination by polyclonal rabbit anti-capsular 15B sera

BackgroundS. pneumoniae (SP) serotypes 15B and 15C are frequent causative agents of invasive pneumococcal disease (IPD), otitis media, and nasopharyngeal colonization in the post PCV13 era. The principal difference between serotypes 15B and 15C is the presence of an O-acetyl group on the pentasaccharide repeating unit of 15B polysaccharide. It remains unclear if antibodies against SP15B polysaccharide demonstrate functional cross reaction with SP15C strains. We compared functional activity of polyclonal rabbit anti-capsular 15B sera against SP15B and SP15C isolates. MethodsUsing flow cytometry we measured complement factors C3c and C4d deposition on SP15B and 15C in the presence of polyclonal rabbit anti capsular 15B sera. We measured the binding of C3c, common to all complement pathways, and C4d, specific to classical pathway, on SP serotypes 15B and 15C when co-incubated with polyclonal rabbit anti capsular 15B sera and antibody depleted complement. Both the proportion of bacteria with complement deposition and the fluorescence intensity were measured. We also measured agglutination as the increase in forward and side scatter. ResultsPolyclonal rabbit anti-capsular 15B sera activated classical pathway resulting in deposition of C4d and C3c at high intensity on all SP15B cells but only achieved limited deposition and intensity of C4 with SP15C. Similarly, polyclonal rabbit anti-capsular 15B sera induced agglutination of SP15B strains in a dose dependent manner and limited agglutination of SP15C. ConclusionsAnti-capsular 15B sera induce limited C4d and C3c deposition, and minimal agglutination with SP15C strains, reflecting lower classical pathway activation in contrast to high C4d and C3c deposition and agglutination of SP15B. These observations support limited functional cross reactivity of anti-15B to SP15C strains and are consistent with the reduction in opsonophagocytic killing of SP15C reported following immunization with vaccines containing 15B polysaccharide.

Mycoplasma synoviae surface-located elongation factor G functions as a cytoadhesin to promote adhesion to synovial sheath cells through binding to vimentin

Mycoplasma synoviae infection has caused serious economic losses to the poultry industry worldwide. The molecular mechanism by which M. synoviae colonizes the synovium and induces synovitis is unclear. In this study, desthiobiotin pull-down and liquid chromatography‐tandem mass spectrometry analyses were used to screen M. synoviae membrane proteins that bind the membrane proteins of synovial sheath cells (SSCs). Among the 128 screened proteins, elongation factor G (EF-G) of M. synoviae was identified as a surface-located protein using colony blotting and dual fluorescence analyses. The immunogenicity of EF-G was confirmed by the preparation of a rabbit polyclonal antibody. EF-G was identified as a cytoadhesin that directly binds to SSCs using indirect immunofluorescence assay and ELISA plate binding assay. In addition, antibody adhesion inhibition and protein adhesion inhibition demonstrated that EF-G could significantly promote the adhesion of M. synoviae to SSCs. Co-IP, GST pull-down, bacterial two-hybridization, and ELISA plate binding assays were performed to demonstrate the binding of EF-G and vimentin in vivo and in vitro. Antibody adhesion inhibition, protein adhesion inhibition, and siRNA interference adhesion inhibition assays demonstrated that vimentin significantly affected M. synoviae adhesion to SSCs. These studies indicate that two interacting proteins, EF-G, a novel cytoadhesin, and vimentin, an important cell surface receptor, play important roles in the adhesion of M. synoviae to SSCs, laying a foundation for subsequent studies on the mechanism of M. synoviae-induced synovitis and providing meaningful targets for screening target drugs against M. synoviae infection.

C-Kit Immunohistochemical Expression as a Complementary Method to Assess Mast Cell Density in Helicobacter Pylori-mediated Gastritis.

Chronic gastritis is a group of conditions commonly characterized by stomach lining inflammation. The study aims to investigate the clinical and pathological aspects that play a role in its development. Additionally, the study examines the use of CD117 as an immunohistochemistry marker in evaluating mast cell density (MCD). This retrospective, cross-sectional study was conducted in Iraqi Kurdistan with a sample size of 380 patients. Patient data included gastritis type, neutrophil infiltration severity, mononuclear cell infiltration within the lamina propria, intestinal metaplasia, and glandular atrophy, which were categorized and given a score. The CD117 level was identified using an anti-human rabbit polyclonal antibody. A statistically significant association was revealed between Helicobacter pylori-mediated gastritis and non-specific gastritis with age, activity, H. pylori and MCD, dysplasia, and malignancy. Meanwhile, no association was found with gender, inflammatory infiltrate, intestinal metaplasia, and glandular atrophy. C-Kit exhibited a marked increase in MCD in patients with H. pylori-mediated gastritis, intestinal metaplasia, atrophy, and gastric carcinoma. However, a significant decrease in MCD was observed on repeating endoscopy evaluations for patients after treatment. Regions that exhibit severe inflammation, metaplasia, atrophy, and carcinoma demonstrated an increase in MCD with H. pylori-mediated gastritis. A detailed investigation in clinical practice to screen early diagnosis and treatment needs to be performed in high H. pylori prevalence.

Development of a double-antibody sandwich ELISA for quantification of mutated EPSPS gene expression in rice

Glyphosate resistance is a critically important trait for genetically modified (GM) crops. Mutation of the rice EPSPS gene results in a high level of glyphosate resistance, presenting significant potential for the development of glyphosate-tolerant crops. The resistance of rice to glyphosate is correlated with the expression levels of resistance genes. Therefore, developing a convenient, stable, and sensitive method for quantifying the OsmEPSPS protein is crucial for the development of glyphosate-resistant crops. We developed a double-antibody sandwich quantitative ELISA (DAS-ELISA) using a specific monoclonal antibody (mAb) for OsmEPSPS capture and an HRP-conjugated anti-OsmEPSPS rabbit polyclonal antibody (pAb). The method could be used to detect OsmEPSPS within a linear range of 16–256 ng/mL with robust intra- and inter-batch duplicability (%CV values: 0.17 %–7.24 %). OsmEPSPS expression in the transgenic rice lines (54.44–445.80 μg/g) was quantified using the DAS-ELISA. Furthermore, the expression of the OsmEPSPS gene was validated through Western blotting. This study demonstrated the reliability and stability of the DAS-ELISA for OsmEPSPS detection in GM rice.

Snail Expression as a Prognostic Factor in Colorectal Adenocarcinoma.

The aim of this study was to analyze the expression of Snail in the colorectal adenocarcinoma. This study used a cross-sectional design. Seventy four paraffin embedded block of Colorectal Adenocarcinoma were assessed using Snail rabbit polyclonal antibody and their expression were performed using Olympus CX-43 light microscope. The relationship between Snail expression with histopathological grading, tumor budding grading, lymphovascular invasion and metastases of colorectal adenocarcinoma ability were statistically analyzed by Mann Whitney tests and presented in tables using SPSS 27. From 74 samples examined, in samples with low grade tumor budding (n=11), there were 9 samples (81.8%) with weak expression, while those with strong expression were 2 samples (18.2%). In samples with intermediate grade tumor budding (n=28), there were 17 samples (60.7%) with weak expression, while those with strong expression were 11 samples (39.3%). In samples with high grade tumor budding (n=35), there were 13 samples (37.1%) with weak expression, while those with strong expression were 22 samples (62.9%). In samples with lymphovascular invasion (n=14), there were 10 samples (71.4%) with strong expression, while those with weak expression were 4 samples (28.6%). In samples with metastases (n=23), there were 16 samples (69.6%) with strong expression, while those with weak expression were 7 samples (30.4%). There was a significant relationship between the expression of Snail with tumor budding grade (p=0.003), lymphovascular invasion and metastases (p=<0.001), but there was no significant relationship with histopathological grade (p=0.942). The Snail expression can be used as a prognostic factor in colorectal adenocarcinoma.

Production of highly soluble and immuno-reactive recombinant flagellin protein of Clostridium chauvoei

ObjectiveFlagellin protein, an integral component of flagella, provides motility to several bacterial species and also acts as a candidate antigen in diagnostics and subunit vaccines. The bulk production of flagellin with retention of all conformational epitopes using recombinant protein technology is of paramount importance in the development of pathogen-specific immuno-assays and vaccines. We describe the production of highly soluble and immuno-reactive rFliA(C) protein of Clostridium chauvoei, a causative agent of blackleg or black quarter (BQ) affecting cattle and small ruminants worldwide. The bacterium is known to possess peritrichous flagella that provide motility and also act as a virulence factor with high protective antigenicity. MethodsUpon sequence and structural analysis, a partial fliA(C) gene from Clostridium chauvoei was cloned and the recombinant mature protein with N- and C- terminal truncation was over-expressed as a His-tagged fusion protein (∼25 kDa) in Escherichia coli. Subsequently, rFliA(C) protein was purified by single-step affinity chromatography and characterized for its immuno-reactivity in laboratory animals, Western blot, and indirect-ELISA format. ResultsrFliA(C) was highly soluble and was purified in high quantity and quality. rFliA(C) elicited antigen-specific conformational polyclonal antibodies in rabbit and guinea pig models, as well as anti-Clostridium chauvoei-specific antibodies being specifically detected in BQ-vaccinated and convalescent sera of bovines in Western blot and in indirect-ELISA format. Further, no cross reactivity was noted with antibodies against major bovine diseases (e.g., foot-and-mouth disease, IBR, LSDV, hemorrhagic septicaemia, brucellosis, and leptospirosis). ConclusionThe study indicated the production of conformational recombinant flagellin—rFliA(C)—antigen and its potential utility in development of diagnostics for detection of Clostridium chauvoei-specific antibodies in BQ-recovered and/or vaccinated animals.

Expression of isocitrate dehydrogenase 1 and tumor protein 53 in high-grade glioma and its correlation with the outcome – A prospective study at a tertiary care center in India

Background: Central nervous system tumors are the 10th most prevalent cause of mortality worldwide. The 2016 World Health Organization (WHO) classification of high grade gliomas (HGG) has identified Isocitrate dehydrogenase 1 (IDH 1) mutation as one of the primary molecular markers. Tumor protein 53 (p53) mutation is also closely associated with HGG. Aims and Objectives: The current study intended to ascertain the expression of IDH1 and P53 in patients with HGG and correlate that expression with clinical prognosis. Materials and Methods: The study included 34 patients with histopathological proven HGG. Relevant clinical information was recorded. The immunostaining results with anti-mouse monoclonal antibody for IDH 1 (R132H) and rabbit polyclonal antibody for p53 (RP 106-05) were statistically analyzed. Patients were followed up through telephone for a period of 1 year. Mortality within 1 year was regarded as a poor outcome. Results: About 85.29% (29/34) of the patients had Grade IV glioma, while only 14.71% (5/34) had Grade III glioma. Most patients with Grade III (3/5) (60.00%) and Grade IV (21/29) (72.41%) gliomas had p53 positivity. The majority of the patients with grade-III glioma (3/5) (60.00%) had IDH1 positivity, while most of the patients (23/29) (79.31%) with Grade IV gliomas had IDH1 negativity (P=0.0658). Age, gender, WHO grade, and adjuvant therapy did not show significant association with the outcome except for the p53 expression (P=0.0011*) and IDH1 expression (P=0.0025*). Correlation analysis showed a significant positive correlation between p53 makers with poor outcome (r=0.4781) and glioma grade (r=0.4028). Further, a negative yet insignificant correlation was recorded between IDH1 with age (r=−0.2285), p53 expression (r=−0.2568), and grade (r=−0.2988), although it showed a significant correlation with poor outcome (P=0.0001). Conclusion: p53-positive and IDH1-negative HGG had a significant correlation with the poor outcome. Thus, IDH1 and p53 are reliable markers for prognostication of HGG.

Immunohistochemical Analysis of CD117 in the Mast Cells of Odontogenic Keratocysts.

Odontogenic lesions contain mast cells (MCs), particularly those with a cystic appearance. Because of their high recurrence rates and aggressive clinical behaviour, odontogenic keratocysts (OKCs) require special treatment. A particular kind of protein called cluster of differentiation (CD) 117/ receptor tyrosine kinase (c-KIT) is present on the surface of many cells. Most hematopoietic cells lose their expression of KIT during the differentiation process, with the exception of MCs, which continue to express KIT throughout their lifetime. Using the CD117 immunomarker, this immunohistochemical investigation sought to assess the presence and location of MCs in OKCs and examine the relationship between MC numbers in sporadic, syndromic, and recurrent OKCs. The study comprised 30 paraffin-embedded tissue specimens, and a histopathological diagnosis was made from hematoxylin and eosin-stained sections with a thickness of 4-5 µ. Out of 30 specimens, 21 were sporadic, six were recurrent OKCs, and three were syndrome-associated OKCs. CD-117/c-kit rabbit polyclonal primary antibody was used to stain the sections for observing MCs, which were then viewed under a light microscope with a digital camera and a desktop computer with MICAPS software for viewing images. To compare the number of MCs among OKCs, a one-way ANOVA test was used. Our study revealed that a statistically significant increase in MCs has been observed in the subepithelial and deep connective tissue of recurrent OKC (p < 0.05). However, a comparison of the mean MC value among three OKC subtypes did not reveal any statistically significant differences. An increased mast count was observed in the deep connective tissue layer of syndromic OKC under multiple comparisons. Our study concluded that MCs were present in increased numbers both in the superficial and deep connective tissue of recurrent OKCs, indicative of their aggressive clinical behaviour. Increased mean MC counts observed in some of the sporadic cases may be an indicator of their chances of recurrence in the future.

Shrimp hemocyanin elicits a potent humoral response in mammals and is favorable to hapten conjugation

Conjugation to a carrier protein is essential to give rise to the antigenicity of hapten. Three carrier proteins e.g. KLH (Keyhole Limpet hemocyanin), BSA (bovine serum albumin), and OVA (Ovalbumin) were used mostly. KLH is advantageous to the others, majorly owing to its strong immunogenicity and limited usage in other biological assays. However, the cost of obtaining Keyhole Limpet is high and the solubility of KLH is not as well as the other carriers, especially after hapten conjugation. Here, we extracted the shrimp hemocyanin (SHC) from Litopenaeus vannamei (L. vannamei), which is a commonly sea product worldwide. The high pure SHC could be acquired by two-step purification, with a production yield of > 1 g proteins (98% pure) per 1 kg shrimp. Compared to KLH, the peptide-SHC conjugates exhibit higher solubility after hapten conjugation. Meanwhile, compared with KLH, SHC induces comparable antibody production efficiency in mammals, with or without conjugation. Furthermore, rabbit polyclonal antibodies or mouse monoclonal antibodies were generated by immunizing SHC-peptide conjugates, and the subsequent antibodies were confirmed to be used in western blot, immunofluorescence and immunohistochemistry. Therefore, we demonstrated that SHC may be used as a substitute for KLH in future antibody and vaccine development.

Monoclonal Antibodies for Rift Valley Fever Virus Nucleocapsid: Application in IgG/IgM ELISA for Sero-Diagnosis.

Rift Valley fever virus (RVFV) belonging to the Phenuiviridae family is responsible for a zoonotic disease called Rift Valley fever (RVF). Currently, RVFV has spread from Africa to Asia, and due to its ability to cause high mortality rates, it has significantly impacted human health and economic development in many societies. Highly specific and sensitive systems for sero-diagnosis of RVFV infection are needed for clinical use. BALB/c mice were immunized with recombinant RVFV nucleocapsid (rRVFV-N) protein and the spleen cells fused with SP2/0 myeloma cells to create hybridoma cell lines. The secreted monoclonal antibodies (MAbs) were purified and characterized. Enzyme-linked immunosorbent assay (ELISA) systems for the detection of IgG and IgM using the new MAbs were established and evaluated. Serum samples from 96 volunteers and 93 patients of suspected RVF from Kenya were tested compared with the ELISA systems based on inactivated viruses and the rabbit polyclonal antibody. Three monoclonal antibodies against rRVFV-N protein were established. The performance of the MAb-based sandwich IgG ELISA and the IgM capture ELISA perfectly matched the ELISA systems using the inactivated virus or the polyclonal antibody. Recombinant RVFV-N protein-specific MAbs were developed and they offer useful tools for RVFV studies. The MAb-based ELISA systems for detecting IgG and IgM offer safe and useful options for diagnosing RVFV infections in humans.

Conjugation with the Carrier Helped to Reveal acidification-Induced Structural Shift in the Peptide from Phospholipase Domain of Parvovirus B19.

Spectroscopic studies on domains and peptides of large proteins are complicated because of the tendency of short peptides to form oligomers in aquatic buffers, but conjugation of a peptide with a carrier protein may be helpful. In this study we approved that a fragment of SK30 peptide from phospholipase A2 domain of VP1 Parvovirus B19 capsid protein (residues: 144-159; 164; 171-183; sequence: SAVDSAARIHDFRYSQLAKLGINPYTHWTVADEELLKNIK) turns from random coil to alpha helix in the acidic medium only in case if it had been conjugated with BSA (through additional N-terminal Cys residue, turning it into CSK31 peptide, and SMCC linker) according to CD-spectroscopy results. In contrast, unconjugated SK30 peptide does not undergo such shift because it forms stable oligomers connected by intermolecular antiparallel beta sheet, according to IR-spectroscopy, CD-spectroscopy, blue native gel electrophoresis and centrifugal ultrafiltration, as, probably, the whole isolated phospholipase domain of VP1 protein does. However, being a part of the long VP1 capsid protein, phospholipase domain may change its fold during the acidification of the medium in the endolysosome by the way of the formation of contacts between protonated His153 and Asp175, promoting the shift from random coil to alpha helix in its N-terminal part. This study opens up a perspective of vaccine development, since rabbit polyclonal antibodies against the conjugate of CSK31 peptide with BSA, in which the structure of the second alpha helix from the phospholipase A2 domain should be reproduced, can bind epitopes of the complete recombinant unique part of VP1 Parvovirus B19 capsid (residues: 1-227).

Development and validation of an ELISA kit for the detection of Staphylococcus aureus enterotoxin A, B, C1, C2, C3, D, E from food samples

Staphylococcus aureus (S. aureus) is a significant food-borne pathogen that poses a threat to human health. The classical serotypes staphylococcal enterotoxin (SE) A, B, C1, C2, C3, D, E produced by S. aureus are the primary cause of its food-borne pathogenic toxicity. Therefore, establishing a highly sensitive, rapid, robust, high-throughput detection method for the total amount of classical serotypes of SEs is crucial for food safety and public health. This study prepared 10 rabbit polyclonal antibodies and 40 mouse monoclonal antibodies targeting SEA, SEB, SEC1, SEC2, SEC3. Upon identifying the optimal antibody pairs through square array method and optimization, a sandwich ELISA kit for the detection of SEs (SEA, SEB, SEC1, SEC2, SEC3, SED, SEE) was developed, with respective limits of detection at 0.169–0.688 ng/mL. In addition, this sandwich ELISA kit could detect SEs in raw cow milk, pasteurized milk, fermented milk, milk powder, whey powder, rice, raw pork, and canned beef samples with coefficients of variation below 7%. Meanwhile, this sandwich ELISA kit was stable at 4 °C for one-year storage. The study fills a research gap in the detection of the total amount of classical serotypes of SEs.

Optimization of DAC-ELISA and IC-RT-PCR using the developed polyclonal antibody and one-step RT-PCR assays for detection of Indian citrus ringspot virus in kinnow orange of Punjab, India

Indian citrus ringspot virus (ICRSV), a member of the Mandarivirus genus, causes citrus ringspot disease, impacting kinnow orange quality and yield. Early and accurate detection methods are crucial before visible symptoms manifest in plants. In this study, a 507 bp partial coat protein gene (pCPG) segment was amplified from infected kinnow leaf tissues, cloned into a pET28a vector, and transformed into E. coli BL21(DE3) cells. Induced with IPTG, the cells overexpressed a recombinant partial coat protein (rpCP) of approximately 23 kDa, purified using Ni-NTA resin via affinity chromatography. Validated in western blot with an anti-His antibody, rpCP was used to generate an ICRSV-specific polyclonal antibody (PAb) in rabbits. PAb, optimized at 1:1000 dilution, successfully detected ICRSV in infected kinnow orange leaf extracts via DAC-ELISA and IC-RT-PCR assays. ICRSV was detectable in sample dilutions up to 1:640 and 1:10240 (w/v, g mL−1) by DAC-ELISA and IC-RT-PCR, respectively. One-step RT-PCR assays were also optimized, confirming the presence of ICRSV by amplifying a 507 bp pCPG fragment from total RNA extracted from kinnow orange leaves, with dilution up to 1:5120 (w/v, g mL−1). The result demonstrated that IC-RT-PCR has a 16-fold and 2-fold higher sensitivity than DAC-ELISA and one-step RT-PCR assays.

TRPS1 function beyond breast: A retrospective immunohistochemical study on non-breast cytology specimens.

Trichorhinophalangeal syndrome type 1 (TRPS1) has emerged as a reliable immunohistochemistry (IHC) marker for identifying breast origin in metastatic carcinomas. This study investigates the utility of TRPS1 IHC in non-breast cytology specimens. A retrospective search of our pathology database for the year 2021 identified fluids (pleural and peritoneal) and liver, lung and bone fine needle aspirations (FNAs) with surgical follow-up confirming non-breast metastatic carcinomas. Cell blocks from cases with sufficient neoplastic cells underwent immunostaining using a rabbit polyclonal antibody against human TRPS1. Cases lacking tumor on deeper levels after the original work-up were excluded from the study. Two pathologists independently interpreted the TRPS1 staining. Of 136 cases assessed, 31 (22.79%) exhibited positive TRPS1 staining, while 105 (77.21%) were nonreactive. Positivity rates were observed in tumors of Mullerian cell origin, gastrointestinal tract (GIT), and lung origin at 28.85%, 25%, and 21.57%, respectively. Of the tumors of Mullerian cell origin 10 (66.67%) were serous carcinomas, 4 (26.67%) were endometrioid carcinomas, and one (6.67%) was a clear cell carcinoma. Lung tumors comprised seven (63.64%) squamous cell carcinomas and four (36.36%) adenocarcinomas, while the gastrointestinal tumors consisted of 14 (80%) adenocarcinomas and one (20%) squamous cell carcinoma. Although recognized as a sensitive marker for mammary carcinomas, TRPS1 immunostaining was also detected in Mullerian, lung, and GIT carcinomas. This highlights the significance of being cautious when depending solely on TRPS1 immunostaining to distinguish metastatic breast tumors.

Phosphorylation of cell cycle and apoptosis regulatory protein-1 by stress activated protein kinase P38γ is a novel mechanism of apoptosis signaling by genotoxic chemotherapy.

CARP-1, a perinuclear phospho-protein, regulates cell survival and apoptosis signaling induced by genotoxic drugs. However, kinase(s) phosphorylating CARP-1 and down-stream signal transduction events remain unclear. Here we find that CARP-1 Serine (S)626 and Threonine (T)627 substitution to Alanines (AA) inhibits genotoxic drug-induced apoptosis. CARP-1 T627 is followed by a Proline (P), and this TP motif is conserved in vertebrates. Based on these findings, we generated affinity-purified, anti-phospho-CARP-1 T627 rabbit polyclonal antibodies, and utilized them to elucidate chemotherapy-activated, CARP-1-dependent cell growth signaling mechanisms. Our kinase profiling studies revealed that MAPKs/SAPKs phosphorylated CARP-1 T627. We then UV cross-linked protein extracts from Adriamycin-treated HeLa cervical cancer cells with a CARP-1 (614-638) peptide, and conducted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses of the peptide-bound protein complexes. This experiment revealed SAPK p38γ interaction with CARP-1 (614-638) peptide. Our studies further established that SAPK p38γ, but not other MAPKs, phosphorylates CARP-1 T627 in cancer cells treated with genotoxic drugs. Loss of p38γ abrogates CARP-1 T627 phosphorylation, and results in enhanced survival of breast cancer cells by genotoxic drugs. CARP-1 T627 phosphorylation was also noted in breast tumors from patients treated with radiation or endocrine therapies. We conclude that genotoxic drugs activate p38γ-dependent CARP-1 T627 phosphorylation to inhibit cell growth.

Экспрессия ARID1a в эндометрии женщин репродуктивного возраста с аномальными маточными кровотечениями и ожирением

Objective. The aim of the study was to evaluate the expression of the proliferative marker ARID1a in endometrial biopsies of patients with abnormal uterine bleeding (AUB) and obesity and its role in the pathogenesis of endometrial dysfunction. Materials and methods. The study included 40 endometrial samples from patients of reproductive age with AUB-E: 20 from patients with AUB-E and obesity (group 1) and 20 from patients with normal body mass index (BMI) and AUB (group 2). 10 endometrial samples were obtained from healthy women of reproductive age, taken on the 2nd-3rd day of the menstrual cycle. All patients underwent histological examination according to the standard procedure. At the second stage, an immunohistochemical study of the ARID1a proliferation marker was performed using polyclonal rabbit antibodies to Anti-ARID1a (clone EPR13501-73) in standard dilution (1:500) according to the protocol of the manufacturer Abcam (Great Britain). The IBM SPSS Statistics v.26 program (IBM Corporation, USA) was used for statistical data analysis. To determine statistically significant differences between quantitative parameters with a normal distribution, one-factor analysis of variance (ANOVA) was used with the calculation of a 95% confidence interval followed by the post-hoc Games-Howell test for multiple comparisons. The differences were considered significant at p&lt;0.05. Results. ARID1a expression was evaluated in the glandular and stromal compartments of the endometrium. In the endometrial glands, the expression of ARID1a was statistically significantly higher in the first group of obese patients compared with the normal and control groups. In the endometrial stroma, the expression of the proliferative marker was higher in the main group compared with the control group. However, when comparing between groups within the main group, statistical significance in the level of expression was not achieved. Conclusion. The results obtained demonstrate the possible pathological effect of obesity on the structural and functional properties of the endometrium, which leads to delayed regeneration of the endometrium due to the glandular component and, consequently, to AUB-E.