Comparison of T cells mediated immunity and side effects of mRNA vaccine and conventional COVID-19 vaccines administrated in Jordan

Various COVID-19 vaccines can affect the immune system. Discrepancies have been noted in immune system characteristics, such as T-lymphocyte levels, between vaccinated and non-vaccinated individuals. This study investigates the variations in immune responses among the four administered COVID-19 vaccines, influencing factors, and clinical outcomes in Jordan. A total of 350 adults, who were at least two doses vaccinated, were interviewed and blood samples were collected for subsequent laboratory analyses. The study involved the quantification of T-cells specifically targeting anti-SARS CoV-2 using Flow cytometry analysis. BNT162b2 (Pfizer) recipients displayed significantly higher CD3+/CD4+ T-helper cell responses (90.84%, 87.46% - 94.22%) compared to non-Pfizer-BioNTech recipients {BBIBP-CorV (Sinopharm) and Sputnik V (Gamaleya Research Institute), then ChAdOx1 nCoV-19 (AstraZeneca)} (83.62%, 77.91% - 89.33%). The CD3+/CD8+ (T cytotoxic) level was notably elevated in non-Pfizer-BioNTech recipients {Sinopharm and Sputnik V then ChAdOx1 nCoV-19 AstraZeneca (73.94%, 69.38% - 78.49%) compared to BNT162b2 (Pfizer) recipients (58.26%, 53.07% - 63.44%). The CD3+ (T-cells) level showed no significant difference between BNT162b2 recipients (73.74%) and non-Pfizer-BioNTech recipients (77.83%), with both types generating T-cells. Comparing two doses of non-Pfizer-BioNTech vaccines with the third dose of BNT162b2 recipients (Pfizer), no difference in the type of immune reaction was observed, with non-Pfizer-BioNTech recipients still stimulating endogenous pathways like cell-mediated cytotoxic effects for cells. All COVID-19 vaccines administered in Jordan were effective, with respect to the total number of T cells. Non-Pfizer-BioNTech had higher in toxic T-cells and Pfizer-BioNTech was higher in helper T-cells that stimulate plasma cells to produce antibodies.

Advanced Nanoencapsulation-Enabled Ultrasensitive Analysis: Unraveling Tumor Extracellular Vesicle Subpopulations for Differential Diagnosis of Hepatocellular Carcinoma via DNA Cascade Reactions

Tumor-derived extracellular vesicles (tEVs) hold immense promise as potential biomarkers for the precise diagnosis of hepatocellular carcinoma (HCC). However, their clinical translation is hampered by their inherent characteristics, such as small size and high heterogeneity and complex environment, including non-EV particles and normal cell-derived EVs, which prolong separation procedures and compromise detection accuracy. In this study, we devised a DNA cascade reaction-triggered individual EV nanoencapsulation (DCR-IEVN) strategy to achieve the ultrasensitive and specific detection of tEV subpopulations via routine flow cytometry in a one-pot, one-step fashion. DCR-IEVN enables the direct and selective packaging of multiple tEV subpopulations in clinical serum samples into flower-like particles exceeding 600 nm. This approach bypasses the need for EV isolation, effectively reducing interference from non-EV particles and nontumor EVs. Compared with conventional analytical technologies, DCR-IEVN exhibits superior efficacy in diagnosing HCC owing to its high selectivity for tEVs. Integration of machine learning algorithms with DCR-IEVN resulted in differential diagnosis accuracy of 96.7% for the training cohort (n = 120) and 93.3% for the validation cohort (n = 30), effectively distinguishing HCC, cirrhosis, and healthy donors. This strategy offers a streamlined workflow and rapid assay completion and requires only small-volume serum samples and routine clinical devices, facilitating the clinical translation of tEV-based tumor diagnosis.

The characteristics and alteration of peripheral immune function in patients with multiple system atrophy

Objective

Multiple system atrophy (MSA) is a degenerative disease. Immune dysfunction found to play a crucial role in the pathogenesis of this disease in the literature, while the characteristics of peripheral immune function remain unclear. This study aimed to investigate the characteristics and alterations of peripheral immune function in patients with MSA.

Methods

A case-control study was conducted between January 2021 to December 2022 at SanBo Brain Hospital, Capital Medical University, Beijing, China. A total of 74 participants were recruited, including 47 MSA patients and 27 non-MSA participants. Peripheral blood samples were collected from each participant. A total of 29 types of immune cells were measured using the flow cytometry analysis technology. Single-factor analysis and multiple-factor analysis (multiple linear regression models) were performed to determine the differences and risk factors in immune cells between the MSA and non-MSA groups.

Results

Alterations of the count or percentage of CD19+ B lymphocytes and CD3-CD56+ B lymphocytes in MSA patients were found in this study. The reductions of the count and percentage of CD19+ B lymphocytes were still robust after adjusting for variables of age, gender, body mass index, albumin, and hemoglobin. Furthermore, the reductions in the count and percentage of CD19+ B lymphocytes in the MSA patients were more significant in women and individuals aged 60 years old or above than in the non-MSA participants.

Conclusion

Our findings suggested that MSA patients may be influenced by B lymphocytes, particularly CD19+ cells. Therefore, the reductions in immune cells should be considered in the diagnosis and treatment of MSA. Further studies are warranted to confirm and expand upon these findings.

The correlation of Th22 and regulatory T cells with Helicobacter pylori infection in patients with chronic gastritis

OBJECTIVE

Helicobacter pylori is planted in the human stomach and is the most common cause of chronic gastritis, which produced specific local and systemic humoral immunity, while the associations of these immune responses and H. pylori in the development of chronic gastritis remain unclear.

METHODS

This study analyzed histology, the number of Th22 and regulatory T (Treg) cells, and the levels of inflammation- and gastritis-related indicators between 22 H. pylori-infected and 24 non-H. pylori-infected chronic gastritis patients by hematoxylin-eosin staining, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR, and flow cytometry analysis.

RESULTS

This study found that the pathological damage degree of gastric mucosa in H. pylori infection patients was more serious. In the H. pylori-infected patient serum, the gastrin, G-17, interleukins (IL)-22, transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α, IL-4, and IL-17A levels were notably raised, while the interferon (IFN)-γ level was inhibited, and in gastric mucosa, and except IFN-γ, the IL-22, forkhead box P3 (Foxp3), TNF-α, IL-4, and IL-17A mRNA levels were raised too. The receiver operating characteristic curve analysis indicates serum IL-22, TGF-β, TNF-α, IL-4, and IL-17A are suitable for differential diagnosis of H. pylori infection. In addition, in the peripheral blood, the percentages of the IL-22⁺ CD4⁺ and Foxp3⁺ CD4⁺ T cells were raised with H. pylori infection. The positive correlation between IL-22 and Foxp3 mRNA levels and the degree of H. pylori colonization and gastric mucositis by Pearson's correlation analysis.

CONCLUSIONS

Treg and Th22 cells were positively associated with the degree of H. pylori infection and the severity of gastritis. In summary, this study provides an experimental basis for the study of the eradication of H. pylori and the biological mechanism of chronic gastritis.

The Impact of Clonal Hierarchy and Heterogeneity on Phenotypic Manifestations of Myelodysplastic Neoplasms

Until recently, conventional prognostication of myelodysplastic neoplasms (MDS) was performed using the revised International Prognostic Scoring System (IPSS-R), with additional adverse prognoses conferred by select mutations. Nonetheless, the clonal diversity and dynamics of coexisting mutations have been shown to alter the prognosis and treatment response in patients with MDS. Often in the process of clonal evolution, various initial hits are preferentially followed by a specific spectrum of secondary alterations, shaping the phenotypic and biologic features of MDS. Our ability to recapitulate the clonal ontology of MDS is a necessary step toward personalized therapy and the conceptualization of a better classification system, which ideally would take into consideration all genomic aberrations and their inferred clonal architecture in individual cases. In this review, we summarize our current understanding of the molecular landscape of MDS and the role of mutational combinations, clonal burden, and clonal hierarchy in defining the clinical fate of the disease.

Rolling Circle Amplification-Assisted Flow Cytometry Approach for Simultaneous Profiling of Exosomal Surface Proteins

Exosomes that carry multiple proteins from the originating cells are known as emerging biomarkers for tumor diagnostics. However, it is still technically challenging to accurately evaluate subtle differences of exosomal membrane proteins. Here, we developed a rolling circle amplification (RCA)-assisted flow cytometry approach (FCA) to simultaneously profile surface proteins and quantify exosomes. In this work, specific anti-CD63 antibody-conjugated magnetic beads were first utilized to capture exosomes. Then, the captured exosomes were bound with DNA primers, which comprise exosomal surface protein-specific recognition aptamers. The RCA reaction generates repeat DNA sequences for fluorescent probe hybridization. Finally, a conventional flow cytometer was introduced to phenotype exosomal protein markers. Such a sensitive RCA-assisted FCA displays an excellent detection limit of 1.3 × 10⁵ exosome/mL. The variable composition of four protein markers on different cell-derived exosomes was sensitively detected through changing the protein-recognition sequence of the DNA primer, which reveals a heterogeneous pattern. Exosomes from different cell sources could be distinguished by the abundance difference of multiple surface proteins. Furthermore, the developed RCA-assisted FCA enabled quantitative analysis of blood samples from lung cancer patients, indicating its potential for early clinical diagnosis and prognosis of cancer.

The Effects of Photosensitizing Dyes Fagopyrin and Hypericin on Planktonic Growth and Multicellular Life in Budding Yeast

Naphthodianthrones such as fagopyrin and hypericin found mainly in buckwheat (Fagopyrum spp.) and St. John’s wort (SJW) (Hypericum perforatum L.) are natural photosensitizers inside the cell. The effect of photosensitizers was studied under dark conditions on growth, morphogenesis and induction of death in Saccharomyces cerevisiae. Fagopyrin and hypericin induced a biphasic and triphasic dose response in cellular growth, respectively, over a 10-fold concentration change. In fagopyrin-treated cells, disruptions in the normal cell cycle progression were evident by microscopy. DAPI staining revealed several cells that underwent premature mitosis without budding, a striking morphological abnormality. Flow Cytometric (FC) analysis using a concentration of 100 µM showed reduced cell viability by 41% in fagopyrin-treated cells and by 15% in hypericin-treated cells. FC revealed the development of a secondary population of G1 cells in photosensitizer-treated cultures characterized by small size and dense structures. Further, we show that fagopyrin and the closely related hypericin altered the shape and the associated fluorescence of biofilm-like structures. Colonies grown on solid medium containing photosensitizer had restricted growth, while cell-to-cell adherence within the colony was also affected. In conclusion, the photosensitizers under dark conditions affected culture growth, caused toxicity, and disrupted multicellular growth, albeit with different efficiencies.

Flow Cytometry Characterization of Pluripotent Transmembrane Glycoproteins on Resident Cervix Uteri Cells in Patients Screened for Cervical Cancer

The aim of this study was to characterize both by flow cytometry analysis and immunohistochemistry cervix uteri cells of nulliparous women screened for cervical intraepithelial neoplasia (CIN) in comparison to a group without CIN by using mesenchymal stem cell-like and hematopoietic lineage markers. A significant expression for CD29, CD38, HLA-I, and HLA-II was correlated positively to the CIN degree and it was more relevant in patients positive for human papilloma virus (HPV). Thus, identification and detailed characterization of pluripotent resident in uteri cells could be a promising therapeutic target.

Effects of the Positive Threshold and Data Analysis on Human MOG Antibody Detection by Live Flow Cytometry

Human autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG Ab) have become a useful clinical biomarker for the diagnosis of a spectrum of inflammatory demyelinating disorders. Live cell-based assays that detect MOG Ab against conformational MOG are currently the gold standard. Flow cytometry, in which serum binding to MOG-expressing cells and control cells are quantitively evaluated, is a widely used observer-independent, precise, and reliable detection method. However, there is currently no consensus on data analysis; for example, seropositive thresholds have been reported using varying standard deviations above a control cohort. Herein, we used a large cohort of 482 sera including samples from patients with monophasic or relapsing demyelination phenotypes consistent with MOG antibody-associated demyelination and other neurological diseases, as well as healthy controls, and applied a series of published analyses involving a background subtraction (delta) or a division (ratio). Loss of seropositivity and reduced detection sensitivity were observed when MOG ratio analyses or when 10 standard deviation (SD) or an arbitrary number was used to establish the threshold. Background binding and MOG ratio value were negatively correlated, in which patients seronegative by MOG ratio had high non-specific binding, a characteristic of serum that must be acknowledged. Most MOG Ab serostatuses were similar across analyses when optimal thresholds obtained by ROC analyses were used, demonstrating the robust nature and high discriminatory power of flow cytometry cell-based assays. With increased demand to identify MOG Ab-positive patients, a consensus on analysis is vital to improve patient diagnosis and for cross-study comparisons to ultimately define MOG Ab-associated disorders.

Biosynthesis of zinc oxide nanoparticles using anjbar (root of Persicaria bistorta) extract and their cytotoxic effects on human breast cancer cell line (MCF-7)

Biosynthesis of nanoparticles (NPs) using biomass is now one of the best methods for synthesising NPs due to their nontoxic and biocompatibility. Plants are the best choice among all biomass to synthesise large-scale NPs. The objectives of this study were to synthesise zinc oxide nanoparticles (ZnO-NPs) using Anjbar (root of Persicaria bistorta) [An/ZnO-NPs] and investigate the cytotoxic and anti-oxidant effects. For this purpose, the An/ZnO-NPs were synthesised by using Bistort extract and characterised using UV-Visible spectroscopy, transmission electron microscope, field emission scanning electron microscope, x-ray diffraction and Fourier-transform infrared spectroscopy. The cytotoxic effects of the An/ZnO-NPs on MCF-7 cells were followed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays at 24, 48, and 72 h. Nuclear morphology changed and apoptosis in cells was investigated using acridine orange/propodium iodide (AO/PI) staining and flow cytometry analysis. The pure biosynthesised ZnO-NPs were spherical in shape and particles sizes ranged from 1 to 50 nm. Treated MCF-7 cells with different concentrations of ZnO-NPs inhibited cell viability in a time- and dose-dependent manner with IC50 about 32 μg/ml after 48 h of incubation. In flow cytometry analysis the sub-G1 population, which indicated apoptotic cells, increased from 12.6% at 0 μg/ml (control) to 92.8% at 60 μg/ml, 48 h after exposure. AO/PI staining showed that the treated cells displayed morphologic evidence of apoptosis, compared to untreated groups.

Flow cytometric analysis of the leukocyte landscape during bleomycin-induced lung injury and fibrosis in the rat

Bleomycin-induced lung injury and fibrosis is a well-described model to investigate lung inflammatory and remodeling mechanisms. Rat models are clinically relevant and are also widely used, but rat bronchoalveolar lavage (BAL) cells are not fully characterized with flow cytometry due to the limited availability of antibodies for this species. We optimized a comprehensive time-dependent flow cytometric analysis of cells after bleomycin challenge, confirming previous studies in other species and correlating them to histological staining, cytokine profiling, and collagen accumulation analysis in rat lungs. For this purpose, we describe a novel panel of rat surface markers and a strategy to identify and follow BAL cells over time. By combining surface markers in rat alveolar cells (CD45⁺), granulocytes and other myeloid cells, monocytes and macrophages can be identified by the expression of CD11b/c. Moreover, different activation states of macrophages (CD163⁺) can be observed: steady state (CD86^-MHC-II^low), activation during inflammation (CD86⁺,MHC-II^high), activation during remodeling (CD86⁺MHC-II^low), and a population of newly recruited monocytes (CD163^-α-granulocyte^-). Hydroxyproline measured as marker of collagen content in lung tissue showed positive correlation with the reparative phase (CD163^- cells and tissue inhibitor of metalloproteinases (TIMP) and IL-10 increase). In conclusion, after a very early granulocytic recruitment, inflammation in rat lungs is observed by activated macrophages, and high release of IL-6 and fibrotic remodeling is characterized by recovery of the macrophage population together with TIMP, IL-10, and IL-18 production. Recruited monocytes and a second peak of granulocytes appear in the transitioning phase, correlating with immunostaining of arginase-1 in the tissue, revealing the importance of events leading the changes from injury to aberrant repair.

Antigen-specific CD8 T cells in cell cycle circulate in the blood after vaccination

Although clonal expansion is a hallmark of adaptive immunity, the location(s) where antigen‐responding T cells enter cell cycle and complete it have been poorly explored. This lack of knowledge stems partially from the limited experimental approaches available. By using Ki67 plus DNA staining and a novel strategy for flow cytometry analysis, we distinguished antigen‐specific CD8 T cells in G₀, in G₁ and in S‐G₂/M phases of cell cycle after intramuscular vaccination of BALB/c mice with antigen‐expressing viral vectors. Antigen‐specific cells in S‐G₂/M were present at early times after vaccination in lymph nodes (LNs), spleen and, surprisingly, also in the blood, which is an unexpected site for cycling of normal non‐leukaemic cells. Most proliferating cells had high scatter profile and were undetected by current criteria of analysis, which under‐estimated up to 6 times antigen‐specific cell frequency in LNs. Our discovery of cycling antigen‐specific CD8 T cells in the blood opens promising translational perspectives.

A Single Extracellular Vesicle (EV) Flow Cytometry Approach to Reveal EV Heterogeneity

Extracellular vesicles (EVs) actively participate in intercellular communication and pathological processes. Studying the molecular signatures of EVs is key to reveal their biological functions and clinical values, which, however, is greatly hindered by their sub-100 nm dimensions, the low quantities of biomolecules each EV carries, and the large population heterogeneity. Now, single-EV flow cytometry analysis is introduced to realize single EV counting and phenotyping in a conventional flow cytometer for the first time, enabled by target-initiated engineering (TIE) of DNA nanostructures on each EV. By illuminating multiple markers on single EVs, statistically significant differences are revealed among the molecular signatures of EVs originating from several breast cancer cell lines, and the cancer cell-derived EVs among the heterogeneous EV populations are successfully recognized. Thus, our approach holds great potential for various biological and biomedical applications.

Comparison study on antioxidant, DNA damage protective and antibacterial activities of eugenol and isoeugenol against several foodborne pathogens

Eugenol and its isomer isoeugenol are both used as flavouring agents or food additives in food products, and have both some similar biological properties. However, the difference in biological activities between eugenol and isoeugenol is rarely studied. In this study, the profiles of antioxidant, DNA-protective effects and antibacterial activities of eugenol and isoeugenol against several common foodborne pathogens were investigated and compared under various experiment conditions. Results showed that eugenol and isoeugenol had strong antioxidant activity, the protective effect against DNA damage and antibacterial activity. In addition, it was found that isoeugenol exhibited the higher biological activities mentioned above than eugenol, which was because isoeugenol had a carbon–carbon double bond closer to the benzene ring compared with eugenol. However, the specific reason needs to be further studied.

Antibacterial activity of a novel fatty acid (14E, 18E, 22E, 26E)-methyl nonacosa-14, 18, 22, 26 tetraenoate isolated from Amaranthus spinosus

CONTEXT

Amaranthus spinosus Linn. (Amaranthaceae), commonly known as ''spiny pigweed'', is used in both Indian traditional system and folk medicine for treatment of infectious diseases for a long time in several traditional herbal medicinal preparations. A novel fatty acid [(14E, 18E, 22E, 26E)-methyl nonacosa-14, 18, 22, 26 tetraenoate] is the major metabolite present.

OBJECTIVE

This study examines the antibacterial potential of the fatty acid isolated from the A. spinosus against some Gram-positive and Gram-negative bacteria.

MATERIALS AND METHODS

Three Gram-positive and seven Gram-negative bacterial strains were used for antibacterial assay. The minimum inhibitory concentration (MIC) of the fatty acid was analysed by dilution method and the effects of the fatty acid on the bacterial membrane were studied in detail by flow cytometry analysis.

RESULTS AND DISCUSSION

All the studied bacterial strains were found to be inhibited at a concentration of 100 μg/mL. Staphylococcus aureus ML-59, Bacillus lycheniformis 10341, Shigella boydii 8, Vibrio cholera 811, Vibrio cholera 854 and Vibrio alginolyteus were susceptible and sensitive to the tested fatty acid with a MIC value of 25 μg/mL. It proved a full spectrum of antibacterial activity associated with alterations in the permeability of bacterial membranes.

CONCLUSION

The fatty acid from the A. spinosus possesses potent antibacterial action.

Influence of ejaculation frequency on seminal parameters

BACKGROUND

Several factors have been shown to influence semen parameters, one of which is sexual abstinence; a clinical criteria included in the semen evaluation to provide maximum sperm quality. The aim of the present study was to assess the effect of a daily ejaculation frequency on conventional and functional semen parameters.

METHODS

Semen samples were collected daily over a period of two weeks of which every second sample per person was processed and analyzed according to the World Health Organization guidelines. Furthermore, mitochondrial function, intracellular reactive oxygen species production and sperm DNA fragmentation were evaluated by flow cytometry.

RESULTS

Total sperm count and seminal volume per ejaculation declined and remained decreased for the duration of the daily ejaculation period. However, conventional parameters such as sperm concentration, motility, progressive motility, morphology, vitality and functional parameters such as sperm plasma membrane integrity, mitochondrial membrane potential and DNA fragmentation was not significantly affected and remained similar to the initial measurement throughout the daily ejaculation period. Despite intra- and inter individual variations, the average values of the basic semen parameters remained above the WHO (2010) reference values throughout the daily ejaculation period. Interestingly, a decreasing trend in intracellular ROS production was observed, although statistically not significant.

CONCLUSIONS

The study shows that an extended 2 week period of daily ejaculation does not have major clinical effects on conventional and functional seminal parameters.

Increased CD11b(+) Gr-1(+) cell population in the placenta after infection with Toxoplasma gondii

Toxoplasma gondii is an obligate intracellular protozoan pathogen that can cross the placenta, resulting in congenital toxoplasmosis with severe fetal brain abnormalities. The molecular mechanisms of immune responses against T. gondii infection in the placenta have largely remained unclear. An analytical method for characterizing phenotypes of immune cells in the placenta by flow cytometry was established and it was found that numbers of CD11b(+) Gr-1(+) cells in the placenta increased significantly after T. gondii infection. These results suggest that innate immune responses play an important role in immunity against T. gondii infection via the feto-maternal interface.

Efficient differentiation of cardiomyocytes from human pluripotent stem cells with growth factors

Human pluripotent stem cells have tremendous replicative capacity and demonstrated potential to generate functional cardiomyocytes. These cardiomyocytes represent a promising source for cell replacement therapy to treat heart disease and may serve as a useful tool for drug discovery and disease modeling. Efficient cardiomyocyte differentiation, a prerequisite for the application of stem cell-derived cardiomyocytes, can be achieved with a growth factor-guided method. Undifferentiated cells are sequentially treated with activin A and BMP4 in a serum-free and insulin-free medium and then maintained in a serum-free medium with insulin. This method yields as much as >75% cardiomyocytes in the differentiation culture within 2 weeks, and the beating cardiomyocytes have expected molecular, cellular, and electrophysiological characteristics. In this chapter, we describe in detail the differentiation protocol and follow-up characterization focusing on immunocytochemistry, quantitative RT-PCR, and flow cytometry analysis.

Brucine, an alkaloid from seeds of Strychnos nux-vomica Linn., represses hepatocellular carcinoma cell migration and metastasis: the role of hypoxia inducible factor 1 pathway

Brucine is an alkaloid derived from the seeds of Strychnos nux-vomica Linn. which have long been used as a traditional medicine for the treatment of hepatocellular carcinoma (HCC) in China. HCC prognosis can be greatly influenced by metastasis. There has thus far been little research into brucine as a source of anti-metastasis activity against HCC. In this study, we revealed that brucine dramatically repressed HepG2 and SMMC-7721 HCC cell migration with few cytotoxic effects. Hypoxia inducible factor 1 (HIF-1) is a key transcription factor mediating cell migration and invasion. Brucine suppressed HIF-1-dependent luciferase activity in HepG2 cells. The transcriptions of four known HIF-1 target genes involved in HCC metastasis, i.e., fibronectin, matrix metallopeptidase 2, lysyl oxidase, and cathepsin D, were also attenuated after brucine treatment. Experiments in vivo showed that an intraperitoneal injection of 5 and 15 mg/kg of brucine resulted in dose-dependent decreases in the lung metastasis of H22 ascitic hepatoma cells. Moreover, a dosage of brucine at 15 mg/kg exhibited very low toxic effects to tumor-bearing mice. Consistently, brucine downregulated expression levels of HIF-1 responsive genes in vivo. Our current study demonstrated the capacity of brucine in suppressing HCC cell migration in vitro and lung metastasis in vivo. The inhibition of the HIF-1 pathway is implicated in the anti-metastasis activity of brucine.

Using an RNA aptamer probe for flow cytometry detection of CD30-expressing lymphoma cells

Aptamers are small molecular ligands composed of short oligonucleotides that bind targets with high affinity. In contrast to antibodies, as synthetic oligonucleotides, aptamers have lower production costs and elicit no antigenic reactions. Therefore, aptamers are potential agents for disease diagnosis and treatment. In this study, we validate a fluorescently labeled RNA aptamer, which has been reported to bind specifically to mouse CD30 proteins in solution, for human CD30 protein recognition on intact cells. The aptamer probe was tested with cultured anaplastic large cell lymphoma and Hodgkin's lymphoma cells that express high levels of CD30. Flow cytometry and fluorescence microscopy showed specific and sensitive binding of the aptamer probe to CD30-expressing lymphoma cells at low concentrations (0.3 nM). Studies performed on multiple cell lines and nuclear cells from healthy donors confirmed that the CD30 aptamer and anti-CD30 antibody, the standard clinical probe, recognized the same set of cells. The potential application of multicolor flow cytometry analysis using the CD30 aptamer probe and antibodies was also shown. In conclusion, the developed CD30 aptamer probe could act as a replacement and/or a supplement for antibodies in the diagnosis of the CD30-expressing lymphomas.

Pseudorabies virus induces apoptosis in tissue culture cells

The process of cell death as a result of exposure to pseudorabies virus (PRV) in cultured cells was examined and specific features characteristic of apoptosis were observed. At early times of infection, externalization of membrane phospholipid phophatidylserine was detected by flow cytometry analysis. During the infection process, caspase 3-like protease activity was induced and the activity increased in a time dependent manner. Cellular DNA degradation was demonstrated by agarose gel electrophoresis. Morphologic changes of the nucleus that included chromatin condensation and margination to the periphery of the nucleus were evident in electron microscopy analysis. These biochemical and morphologic changes demonstrated that, during PRV replication, the host cell was induced to undergo apoptosis.

Fate of intravenously administered rat lymphokine-activated killer cells labeled with different markers

Rat lymphokine-activated killer (LAK) cells, generated by adhering rat splenocytes isolated from the 52% Percoll density fraction to plastic flasks, demonstrate restricted in vivo tissue distribution, localizing in the lungs and liver after 2 h, but redistributing into the liver and spleen 24 h after i.v. administration. However, a different pattern of distribution was observed when this population of LAK cells was labeled with one of four commonly used radioisotopes. For example, LAK cells showed a high distribution into the lungs 30 min after administration when labeled with 51Cr, 125I-dUrd or 111In-oxine, whereas 111InCl-labeled LAK cells showed an equal distribution into the blood, lungs and liver at this time. Two hours after administration, cells labeled with 111In-oxine showed an equivalent distribution into the lungs and liver, those labeled with 125I-dUrd or 51Cr showed a high accumulation in the lungs, whereas those labeled with 111In-Cl entered more into the liver and blood. The pattern of distribution of 111In-Cl- or 111In-oxine-labeled cells was confirmed using gamma camera imaging analysis. By 24 h, LAK cells labeled with 111InCl, 111In-oxine or 51Cr distributed in the liver and spleen in variable concentrations. In contrast, cells labeled with 125I-dUrd were not detected in any organ tested. This study was paralleled by monitoring the distribution of LAK cells labeled with Hoechst 33342 (H33342) and analyzed for the presence of fluoresceinated cells in different organs either by flow cytometry analysis, or in frozen section. The data indicate that the distribution pattern of LAK cells labeled with 111In-oxine is the closest to the distribution of H33342-labeled cells. Of all the radioisotopes used, 125I-dUrd has the most disadvantages and is not recommended for monitoring the in vivo distribution of leukocytes.