Migration, Distribution, and Safety Evaluation of Specific Phenotypic and Functional Mouse Spleen-Derived Invariant Natural Killer T2 Cells after Adoptive Infusion

Herein, the migration distribution and safety of specific phenotypic and functionally identified spleen-derived invariant natural killer T2 (iNKT2) cells after adoptive infusion in mice were studied. The proliferation and differentiation of iNKT cells were induced by intraperitoneal injection of α-galactosylceramide (α-GalCer) in vivo. Mouse spleens were isolated in a sterile environment. iNKT cells were isolated by magnetic-activated cell sorting columns (MS columns). Cytometric bead array (CBA) assay was used to detect cytokine secretion in the supernatant stimulated by iNKT cells. The basic life status of the mice was observed, and systematic quantitative scoring was conducted after injecting spleen-derived iNKT cells through the tail vein. An in vivo imaging system was used to trace the migration and distribution of iNKT cells in DBA mice. The percentage of the iNKT2 subgroup was the highest in 3 days after intraperitoneal injection of α-GalCer, and iNKT2 subsets accounted for more than 92% after separation and purification by magnetic-activated cell sorting (MACS). Anti-inflammatory cytokine IL-4 was mainly found in the supernatant of cell cultures. The adoptive infusion of iNKT cells into healthy mice resulted in no significant change in the basic life status of mice compared with the noninjected group. iNKT cells were detected in the lung, spleen, and liver, but no fluorescence was detected in lymph nodes and thymus. After dissecting the mice, it was found that there were no significant abnormalities in the relevant immune organs, brain, heart, kidney, lung, and other organs. Intraperitoneal injection of α-GalCer results in a large number of iNKT2 cells, mainly secreting anti-inflammatory cytokine IL-4, from the spleen of mice. After adoptive infusion, the iNKT2 cells mainly settled in the liver and spleen of mice with a satisfactory safety profile.

A new method for obtaining bankable and expandable adult-like microglia in mice

Background The emerging role of microglia in neurological disorders requires a novel method for obtaining massive amounts of adult microglia. We aim to develop a new method for obtaining bankable and expandable adult-like microglia in mice. Methods The head neuroepithelial layer (NEL) that composed of microglial progenitor and neuroepithelial cells at mouse E13.5 was dissected and then cultured or banked. Microglia (MG) isolated from the cultured NEL by magnetic-activated cell sorting system were obtained and named NEL-MG. Results The NEL included microglia progenitors that proliferate and ramify over time with neuroepithelial cells as feeder. In functional analysis, NEL-MG exhibited microglial functions, such as phagocytosis (microbeads, amyloid β, synaptosome), migration, and inflammatory response following lipopolysaccharide (LPS) stimulation. NEL was passage cultured and the NEL-MG exhibited a higher expression of microglia signature genes than the neonatal microglia, a widely used in vitro surrogate. Banking or long-term passage culture of NEL did not affect NEL-MG characteristics. Transcriptome analysis revealed that NEL-MG exhibited better conservation of microglia signature genes with a closer fidelity to freshly isolated adult microglia than neonatal microglia. NEL-MG could be re-expandable when they were plated again on neuroepithelial cells. Conclusions This new method effectively contributes to obtaining sufficient matured form of microglia (adult-like microglia), even when only a small number of experimental animals are available, leading to a broad application in the field of neuroscience.

Magnetic Activated Cell-Sorting Identifies a Unique Lung Microbiome Community Associated with Disease States

Background: The advent of culture-independent, next-generation DNA sequencing has led to discovery of distinct lung bacterial communities. Studies of lung microbiome taxonomy often reveal only subtle differences between health and disease, but microbial host response may distinguish members of similar communities in different populations. Magnetic-activated cell sorting has been applied to the gut microbiome to identify numbers and types of bacteria eliciting a humoral response. We adapted this technique to examine populations of immunoglobulin-bound bacteria and investigate the lung microbiota in Human Immunodeficiency Virus (HIV) as a representative disease.Methods: 42 people living with HIV and 22 HIV-uninfected individuals underwent bronchoalveolar lavage. We separated immunoglobulin G-bound bacteria using magnetic-activated cell sorting and sequenced the 16S rRNA gene on the Illumina MiSeq platform. We analyzed microbial sequencing data and quantified cytokines and bacterial rRNA copy numbers from bronchoalveolar lavage. Results: Immunoglobulin G-bound bacteria were detectable in the healthy lung microbiota. Comparison of raw bronchoalveolar lavage by HIV status showed no significant taxonomic differences, but the immunoglobulin-bound lung microbiota differed by HIV status with greater abundance of Pseudomonas in people living with HIV. Lung cytokine levels were also higher in people living with HIV, which correlated with increased quantity of immunoglobulin G-bound bacteria. Conclusions: We report a novel application of magnetic-activated cell sorting to identify immunoglobulin G-bound bacteria in the lung. This technique identified distinct bacterial communities which differed in composition from raw bronchoalveolar lavage, revealing differences in health and disease not detected by traditional analyses. Cytokine response was also associated with differential immunoglobulin binding of lung bacteria, suggesting functional importance of these communities.

A Simple Approach for Counting CD4+ T Cells Based on a Combination of Magnetic Activated Cell Sorting and Automated Cell Counting Methods

Frequent tests for CD4+ T cell counting are important for the treatment of patients with immune deficiency; however, the routinely used fluorescence-activated cell-sorting (FACS) gold standard is costly and the equipment is only available in central hospitals. In this study, we developed an alternative simple approach (shortly named as the MACS-Countess system) for CD4+ T cell counting by coupling magnetic activated cell sorting (MACS) to separate CD4+ T cells from blood, followed by counting the separated cells using CountessTM, an automated cell-counting system. Using the cell counting protocol, 25 µL anti-CD4 conjugated magnetic nanoparticles (NP-CD4, BD Bioscience) were optimized for separating CD4+ T cells from 50 µL of blood in PBS using a DynamagTM-2 magnet, followed by the introduction of 10 µL separated cells into a CountessTM chamber slide for automated counting of CD4+ T cells. To evaluate the reliability of the developed method, 48 blood samples with CD4+ T cell concentrations ranging from 105 to 980 cells/µL were analyzed using both MACS-Countess and FACS. Compared with FACS, MACS-Countess had a mean bias of 3.5% with a limit of agreement (LoA) ranging from −36.4% to 43.3%, which is close to the reliability of the commercial product, PIMA analyzer (Alere), reported previously (mean bias 0.2%; LoA ranging from −42% to 42%, FACS as reference). Further, the MACS-Countess system requires very simple instruments, including only a magnet and an automated cell counter, which are affordable for almost every lab located in a limited resource region.

Use of alginate hydrogel to improve long-term 3D culture of spermatogonial stem cells: stemness gene expression and structural features

Summary The quality and quantity of a spermatogonial stem-cell (SSC) culture can be measured in less time using a 3D culture in a scaffold. The present study investigated stemness gene expression and the morphological and structural characterization of SSCs encapsulated in alginate. SSCs were harvested from BALB/c neonatal mice testes through two-step mechanical and enzymatic digestion. The spermatogonial populations were separated using magnetic-activated cell sorting (MACS) using an anti-Thy1 antibody and c-Kit. The SSCs then were encapsulated in alginate hydrogel. After 2 months of SSC culturing, the alginate microbeads were extracted and stained to evaluate their histological properties. Real-time polymerase chain reaction (PCR) was performed to determine the stemness gene expression. Scanning electron microscopy (SEM) was performed to evaluate the SSC morphology, density and scaffold structure. The results showed that encapsulated SSCs had decreased expression of Oct4, Sox2 and Nanos2 genes, but the expression of Nanog, Bcl6b and Plzf genes was not significantly altered. Histological examination showed that SSCs with pale nuclei and numerous nucleolus formed colonies. SEM evaluation revealed that the alginate scaffold structure preserved the SSC morphology and density for more than 60 days. Cultivation of SSCs on alginate hydrogel can affect Oct4, Sox2 and Nanos2 expression.

Application and utility of alternative methods in isolation of pure cells from forensic biological mixtures in modern-day: a review

Development of genetic profiles from the biological mixtures has remained challenging, although modern-day technologies may help forensic scientists to attain a reliable genetic profile in the identification of the accused. In the case of rape, vaginal swab exhibits usually contain epithelial cells of victims and sperm cells of accused, such samples are more challenging when there is more than one contributor. In such cases, separation of distinct cells from a mixture that includes blood cells, epithelial cells and sperm cells for their single genetic profile is important. In the last ten decades several new techniques were developed and invented for the separation of single cell from the biological mixture that includes differential lysis, laser micro-dissection, cell sorting (FACS), sieve-based filtration, (vi) micro-fluidic devices or immunomagnetic beads cell separation of fresh samples, and the magnetic activated cell sorting (MACS). Out of them, some techniques have been commonly applied for cell separation in forensic biology. Each technique has its own limitation. Some recent studies showed, magnetic activated cell sorting (MACS), laser capture microdissection (LCM), DEPArray technology and fluorescence activated cell sorting (FACS) has proved to be effective in separation of single cell from cell mixtures. Therefore, in this review we have evaluated these four alternative methods and their potential application in the modern-day over the others for the separation of a single cell from the mixture. In this review we also discuss the advantage of these methods and their modern–day applicability and acceptance in the forensic world.

P–005 Magnetic-activated cell sorting in couples undergoing preimplantation genetic testing for aneuploidies (PGT-A) using autologous oocytes shows slightly lower aneuploidy rates compared to standard semen processing

Study question Does the selection of non-apoptotic sperm via magnetic-activated cell sorting (MACS) reduce the aneuploidy rate of embryos from couples undergoing ICSI cycles with PGT-A using the patients’ own oocytes? Summary answer It does. The aneuploidy rate in the MACS group was 4.34% lower than the one obtained using semen samples processed according to standard clinical practice. What is known already MACS is a successful tool in eliminating proapoptotic sperm from a semen sample. However, the true effect of this technique on reproductive outcomes and the quality of the resulting embryos are a matter of controversy. Some studies report that its use improves the percentage of good quality blastocysts in women older than 30 years old compared to standard ICSI. Randomized clinical trials that compare MACS to a control sample consider parameters of embryo quality such as morphology at day 3 or day 5, symmetry of the blastomeres, blastocysts’ stage of expansion, but they do not consider embryo ploidy. Study design, size, duration Retrospective, multicentre, observational cohort study. 14,145 patients and 18,710 cycles were evaluated in the reference group. In the MACS group, 615 patients and 974 cycles were considered. Data were exported from cycles performed in Spanish IVIRMA clinics between January 2008 and February 2020. Participants/materials, setting, methods Unselected males in couples undergoing PGT-A cycles, then subdivided into male factor (MF) - total progressive motile sperm count lower than 5 million - and non-male factor (NMF) infertility. Statistical analysis performed using R v.4.0.0. Means were calculated and compared using two-tailed paired t-test, while proportions were compared using Fisher’s exact test and the chi-squared test and the appropriate correction for multiple comparisons. The aneuploidy rates for each group were compared using Fisher’s exact test. Main results and the role of chance In the control group 73,228 biopsied embryos, from which 71,439 were informative in the PGT-A. In the MACS group 3,919 biopsied embryos, from which 3,843 were informative. The aneuploidy rate, computed per informative embryo, was 68.87% (68.40%, 69.34%) in the reference group and 64.53% (62.43%, 66.64%) in the MACS group. Both comparisons were statistically significant (p-value ˂0.00001). According to these results, an embryo in the PGT-A programme using non-apoptotic sperm selected through MACS and autologous oocytes had a 5% less chance of being aneuploid than those embryos fertilised with standardly selected sperm (relative risk of 0.95 (0.91–0.98) p = 0.006769). Embryos conceived from NMF patients whose semen had been processed using MACS had a 4.27% lower aneuploidy rate than the reference (65.52% (63.16%, 67.88%) vs 69.79% (69.20%, 70.37%) respectively). This difference was statistically significant. Those embryos conceived using semen from patients with MF using MACS also showed a lower aneuploidy rate than the reference with MF (0.28% (55.48%, 65.08%) vs (64.94% (63.35%, 66.23%) respectively), although this difference was not statistically significant. Thus, the decrease in aneuploidy rate observed when comparing MACS and reference groups undergoing PGT-A cycles using autologous oocytes remained approximately the same in both MF and NMF semen samples. Limitations, reasons for caution The retrospective nature of the study subjects the data to biases or inaccuracies in their annotation in the clinics’ informatic platform from which they were exported. However, the statistical analysis aimed at controlling these biases as much as possible. Wider implications of the findings: The vast amount of data compiled for this study confirms that the selection of non-apoptotic sperm through MACS slightly decreases the aneuploidy rate of embryos compared to semen samples processed according to the clinics’ standards. This would be interesting for patients who are considering undergoing PGT-A cycles in the future. Trial registration number Not applicable

P–081 Microfluidic sorting does not improve clinical outcomes compared to magnetic activated cell sorting (MACS) in Assisted Reproduction

Study question Does microfluidic sorting improve clinical outcomes over magnetic activated cell sorting (MACS) in ovum donation cycles? Summary answer Performing microfluidic sorting does not seem to improve clinical outcomes compared to MACS in ovum donation cycles. What is known already Novel sperm selection techniques, such as magnetic activated cell sorting (MACS), have been described as useful procedures to increase reproductive outcomes when male factor is present. Because of centrifugation steps associated to swim-up or density-gradient can induce sperm DNA fragmentation, microfluidic sperm sorters are being used to isolate motile human spermatozoa based on fluid dynamics and avoiding sample manipulation. This new technology has been shown to reduce the level of sperm DNA damage, especially double strand breaks, but an improvement of clinical outcome by using this technique remain unclear. Study design, size, duration Prospective and observational study to evaluate the efficacy of a sperm sorting technique based on microfluidic technology versus a technique based on the removal of apoptotic spermatozoa by MACS. The study was performed between May 2019 to January 2021 in IVI Madrid and IVI Sevilla. All men attending for an ovum donation cycle during the aforementioned study period were included. The exclusion criteria were sperm concentration <5 mill/mL and <15% of progressive motile spermatozoa. Participants/materials, setting, methods Seminal samples from couples participating in the study were divided into two aliquots; each of them was processed according to one of the study methods. Subsequently, each of the processed sperm samples was used to microinject half of the oocytes obtained during oocyte retrieval. In all case, a single-embryo transfer was performed. Variables were expressed as mean values and standard deviations. Statistical analysis was performed by ANOVA and Chi-squared where applicable; significance established under 0.05. Main results and the role of chance We included 48 couples in the study; of these, n = 31 transferred an embryo derived from a MACS processed sperm sample, while n = 17 received an embryo from the microfluidic one. Groups were homogeneous in terms of number of transferred embryos and frozen embryos, usable blastocyst rate and fertilization rate; results were as follows for MACS and microfluidic processing respectively: number of transferred embryos (1.0±0.0 vs. 1.0±0.0, p = 0.978); number of frozen embryos (1.6±0.5 vs. 1.4±0.7 p = 0.168); usable blastocyst rate (40.7% vs. 43.1%, p = 0.384); and fertilization rate (80.4% vs. 75.3%, p = 0.075). However, according clinical outcomes, we observed significant differences in implantation rate (74.2% vs. 58.8%, p < 0.001) and in clinical pregnancy rate (74.2% vs. 58.8%, p < 0.001); finally, the miscarriage rate was similar between the two groups of study (6.4% vs. 5.8%, p = 0.876). Limitations, reasons for caution This study has not considered the indication in male factor couples due to a high degree of double-strand DNA fragmentation. Therefore, more specific studies are required to determine in which patients, microfluidics sorter selection would significantly improve clinical outcomes. Wider implications of the findings: In an unselected population, magnetic activated cell sorting significantly improves clinical outcomes compared to a microfluidic technique, so this latter method should not be recommended without a male factor indication associated with sperm DNA damage. The proposed microfluidic technology does not seem to offer a flow-free approach to select spermatozoa. Trial registration number NCT04061486