Killing Rate Research Articles

A ·OH self-suppling and dual regulation hybrid nanozyme combined with photothermal therapy to eliminate biofilms and eradicate infections

Limited by local H2O2 concentration and GSH hindrance, chemodynamic therapy (CDT) has poor antibacterial efficiency, and the pro-inflammatory response caused by CDT is often ignored. Here, a hybrid nanozyme (Fe3O4-CaO2-PDA) was synthesized, which has dual regulatory functions of ·OH and GSH, there are two stages in clearing the infection: treatment and repair. In the treatment stage, stimulated by the photothermal generated by near-infrared light (NIR), it rapidly releases a large amount of ·OH and further enhances CDT by decreasing the local GSH concentration to achieve a rapid antimicrobial effect. In the repair stage, the PDA removes the local residual ·OH, prevents over-aggregation of inflammatory cells, and regulates pro-inflammatory responses. In vitro antibacterial experiments showed that the killing rates of the hybrid nanozyme against S. aureus and E. coli were 90% and 92% respectively. At the same time, the DCFH-DA fluorescence experiment showed that the ·OH concentration was significantly controlled. in vivo, due to the function of control ·OH, nanozymes show the ability to promote collagen regeneration and regulate inflammation. In summary, this study proposed a synergistic multiple antibacterial strategy and successfully constructed a PTT-enhanced multifunctional hybrid nanozyme for efficient CDT anti-infective treatment.

Hydantoin derivative dimers as broad-spectrum antimicrobial agents against ESKAPE pathogens with enhanced killing rate and stability.

A new series of hydantoin derivative dimers as potential broad-spectrum antibiotic agents is designed and synthesized to combat ESKAPE pathogens. As membrane-active antimicrobial agents, in addition to cationic charged and hydrophobic groups that mimic AMPs (antimicrobial peptides), hydantoin backbones and aromatic linkers increased the rigidity and lipophilicity of the designed compounds, thus improving the stability and bactericidal killing rate. After whole cell phenotypic screening against eight bacterial strains, including MRSA (methicillin-resistant S. aureus), compound 18 was chosen as the lead compound with overall excellent broad-spectrum antibacterial activity (GM = 7.32 μg mL-1) and good selectivity. Kill-kinetic studies of compound 18 showed that the bacterial growth of both Gram-positive and Gram-negative was completely inhibited within one hour, which demonstrated excellent sterilization efficiency of 18. Furthermore, drug resistance and mechanism studies showed that compound 18 exhibited a steady antibacterial performance during 25 passages and could disrupt bacterial cell membrane integrity and cause cell death. Along with the facile synthesis procedures in solution, this series of hydantoin derivative dimer compounds could be an appealing next generation of antibiotic agents to combat emergent drug resistance.

To Check Efficacy of Different Disinfectants by Kelsey Sykes Method

The incidence of hospital and community acquired infections has globally increased worldwide. The concentration of the disinfectants is important to give its higher efficacy against pathogens or microorganisms. Microorganisms are part of or environment cause major or severe diseases to reduce the risk of these diseases we generally clean surrounding by using cleaning agents like soaps, antiseptics or disinfectants. So to check weather these disinfectants are performs there work against specific bacteria or microorganism we performed this test to check the effectiveness of disinfectants against specific microorganism and fungus. Five bacterial types that are frequently acquired in hospitals from which two are gram positive organism, two are gram negative organism and single strain of fungus ‘(Pseudomonas aeruginossa, Klebsiella pneumoniae, Staphylococcus aureus (MRSA), Acinetobacter baumannii, Candida tropicalis) (clinical isolates) were examined for their susceptibility against 3 commonly used disinfectants hospitals Chlorine releasing agent, Quaternary ammonium compound and Aldehyde free disinfectant). The turbidity in the nutrient broth and the growth in culture media showed that all three disinfectants had lowered the microbial growth of every clinical strain. In general, the reference strains have lower growth and turbidity than the clinical strains. When combined, our results demonstrated that every product we examined had a high disinfection killing rate against microorganisms from various sources, indicating the excellent caliber of these goods. In response to rising disinfectant usage, hand sanitizer production has expanded to keep up with demand. Normal flora or microorganisms are part of our body in everyday life in which some are necessary some are unnecessary and can cause major or severe diseases to avoid from these diseases we generally clean our self and surrounding by using cleaning agents like soaps, antiseptics or disinfectants. So, to check weather these sterilizing agents are performed their work against specific bacteria or microorganism we performed this test to check the effectiveness of disinfectants against specific microorganism and fungus.

Time-kill kinetics of Piper betle L. ethanolic leaf extract on methicillin-sensitive Staphylococcus aureus

Staphylococcus aureus is one of the main pathogens in community and hospital infections that could cause mild skin infections to severe life-threatening bacteremia. Piper betle has shown antibacterial activities against S. aureus but its pharmacodynamics remains unclear despite its widespread availability in many over-the-counter preparations. This study aimed to describe the time-kill kinetics of P. betle extract against methicillin-sensitive Staphylococcus aureus ATCC 29213 (MSSA). Time-kill kinetics were conducted to describe the killing rate of P. betle extract by its effects on MSSA lag time duration, growth rate, and maximum optical density. The surviving colonies at different time-points after exposure to P. betle extract at minimum bactericidal concentration were also determined. Subinhibitory concentrations elucidated its concentration-dependent antibacterial activity by maintaining a trend of increasing lag time, decreasing growth rate, and decreasing maximum optical density as the concentration increases. In particular, concentration at 1250 μg/mL or 0.5 x minimum inhibitory concentration (MIC) showed consistent significant findings across these parameters. Concentrations at MIC and above did not show growth, indicating MSSA growth inhibition or death. P. betle extract’s bactericidal effect started immediately within two (2) hours and was sustained until no growth was observed from the eighth hour and beyond. P. betle extract maintained antibacterial activities against MSSA at subinhibitory concentrations and has also exhibited immediate and sustained bactericidal effect at minimum bactericidal concentration (MBC).

Anti-Proliferative and Apoptotic Activities of Rumex crispus.

Colorectal cancer is the fourth leading cause of cancer death and the third most common cancer diagnosed in the United States. Several anticancer compounds from natural products have been of great interest in cancer chemotherapy and are currently in clinical trials. Natural products that present the targeted killing of cancerous cell and are soluble in water with minimal side effects are ideal candidates. In this study, water-soluble compounds from Rumex crispus plants were screened for anti-proliferative and apoptotic activity against human colorectal adenocarcinoma (DLD-1) cells. The most potent fraction with the highest cell killing and caspase fold change rates was selected for further experiments. The observed changes were further validated by measuring the caspase fold change using RT-qPCR. Furthermore, gene transcript levels were evaluated using an RT2 Profiler assay and a microarray experiment. Our results showed that the most potent L19 fraction exhibits anti-proliferative activity in a dose-dependent manner. The L19 fraction was found to induce apoptotic pathways by triggering different caspases and inflammatory pathways through the activation of non-apoptotic genes. Our study identified and validated the anticancer property of the L19 fraction, which can serve as a strong lead compound for the synthesis of other novel potent analogues.

Antibacterial Activity of Andaliman Ethanol Extract (Zantoxylum Acanthopodium Dc.) Against Porphyromonas Gingivalis Bacteria

Periodontitis is a destructive inflammatory disease of the supporting tissues of the teeth that causes further damage to the periodontal ligament, alveolar bone to the formation of pockets, and decreased gums caused by the bacterium Porphyromonas gingivalis. The most common and frequent periodontal disease is chronic periodontitis which is caused by the accumulation of plaque and calculus. Alternative treatment using herbal ingredients such as andaliman fruit (Zantoxylum acanthopodium DC.) has therapeutic benefits because of its broad biological activity, and lower side effects. Andaliman fruit (Zantoxylum acanthopodium DC.) contains active compounds such as phenolic compounds, saponins, flavonoids, tannins, triterpenoids, steroids, and alkaloids that act as antibacterial. The aim of this study was to determine the minimum inhibitory level (MIC) and minimum killing rate (MBC) of andaliman fruit ethanol extract against Porphyromonas gingivalis bacteria. The research procedure used for the MIC and MBC tests was broth microdilution and the number of colonies was counted using the total plate count (TPC) with variations of 6 concentrations of andaliman fruit ethanol extract with 10% DMSO solvent and 0.2% Chlorhexidine. Statistical analysis in this study was performed using Levene Statistics and Post Hoc Dunnet T3. The ethanol extract of andaliman fruit has a minimum inhibitory concentration (MIC) and a minimum killing concentration (MBC) against the growth of Porphyromonas gingivalis bacteria. The minimum inhibitory concentration in the ethanol extract of andaliman fruit was at a concentration of 25%, while the minimum killing concentration was at a concentration of 100%.

Synthesis and Characterizations of Physical and Antibacterial Properties of the Ag Nanoparticles by Exploding of Wire Technique

In this research, the explosive wire method is used to prepare silver nanoparticles and study their effect on two types of bacteria, E. coli and Staphylococcus aureus. The X-ray diffraction pattern of silver nanoparticles after deposition on glass pieces shows a peak of silver and silver oxide. The FE-SEM morphology of silver oxide particles shows small spherical-like clusters of irregular flower-shaped particles. Meanwhile, the AFM analysis of the silver nanoparticles shows that the average roughness of the aggregates is 57 nm and the average size of the nanoparticles is 20.92 nm. The study of the effect of silver nanoparticles on two types of bacteria, namely E. coli and Staphylococcus aureus, has shown that these nanoparticles have achieved a killing rate of 99% for both types of bacteria.

Manufacture of CD22 CAR T cells following positive versus negative selection results in distinct cytokine secretion profiles and γδ T cell output

Chimeric antigen receptor Tcells (CART) have demonstrated curative potential for hematological malignancies, but the optimal manufacturing has not yet been determined and may differ across products. The first step, Tcell selection, removes contaminating cell types that can potentially suppress Tcell expansion and transduction. While positive selection of CD4/CD8 Tcells after leukapheresis is often used in clinical trials, it may modulate signaling cascades downstream of these co-receptors; indeed, the addition of a CD4/CD8-positive selection step altered CD22 CART potency and toxicity in patients. While negative selection may avoid this drawback, it is virtually absent from good manufacturing practices. Here, we performed both CD4/CD8-positive and -negative clinical scale selections of mononuclear cell apheresis products and generated CD22 CARTs per our ongoing clinical trial (NCT02315612NCT02315612). While the selection process did not yield differences in CART expansion or transduction, positively selected CART exhibited a significantly higher invitro interferon-γ and IL-2 secretion but a lower invitro tumor killing rate. Notably, though, CD22 CART generated from both selection protocols efficiently eradicated leukemia in NSG mice, with negatively selected cells exhibiting a significant enrichment in γδ CD22 CART. Thus, our study demonstrates the importance of the initial Tcell selection process in clinical CART manufacturing.

Comparison of the inoculum effect of in vitro antibacterial activity of Imipenem/relebactam and Ceftazidime/avibactam against ESBL-, KPC- and AmpC-producing Escherichia coli and Klebsiella pneumoniae

ObjectiveTo evaluate effect of inoculum size of extended-spectrum β-Lactamase (ESBL)-producing-, AmpC-producing-, and KPC-producing Escherichia coli and Klebsiella pneumoniae on the in vitro antibacterial effects of imipenem/relebactam (IMR) and ceftazidime/avibactam (CZA).MethodsWe compared the impact of inoculum size on IMR and CZA of sixteen clinical isolates and three standard isolates through antimicrobial susceptibility tests, time-kill assays and in vitro PK/PD studies.ResultsWhen inoculum size increased from 105 to 107 CFU/mL, an inoculum effect was observed for 26.3% (5/19) and 52.6% (10/19) of IMR and CZA, respectively; time-kill assays revealed that the concentration of CZA increased from ≥ 4 × MIC to 16 × MIC to reach 99.9% killing rate against K. pneumoniae ATCC-BAA 1705 (KPC-2-, OXA-9- and SHV-182-producing) and 60,700 (SHV-27- and DHA-1-producing). While for IMR, a concentration from 1 × MIC to 4 × MIC killed 99.9% of the four strains. When the inoculum size increased to 109 CFU/mL, neither IMR nor CZA showed a detectable antibacterial effect, even at a high concentration. An in vitro PK/PD study revealed a clear bactericidal effect when IMR administered as 1.25 g q6h when inoculum size increased.ConclusionAn inoculum effect on CZA was observed more frequent than that on IMR. Among the β-lactamase-producing strains, the inoculum effect was most common for SHV-producing and KPC-producing strains.

Developing a mechanistic translational PK/PD model for a trifunctional NK cell engager to predict the first-in-human dose for acute myeloid leukemia.

Natural killer cell engagers (NKCEs), a treatment that stimulates innate immunity, have lately gained attention owing to their favorable safety profile, and their efficacy. Natural killer (NK) cell activation is driven by immune synapse formation between drugs, NK cells, and tumor cells. However, no clear translational modeling approach has been reported for first-in-human (FIH) dose estimation of humanized NKCEs. We developed the first translational mechanistic synapse-driven pharmacokinetic/pharmacodynamic (PK/PD) model for a trifunctional NKp46/CD16a-CD123 (CD123-NKCE) by integrating (i) invitro target cell cytotoxicity in MOLM-13 tumor cell lines at varying effector-to-tumor cell ratios and incubation intervals; (ii) nonhuman primate PK and profiles of CD123+ cells and NKP46+ NK cells; and (iii) healthy human or patients with acute myeloid leukemia system-specific parameters. To depict direct tumor cell killing by the innate immunity, no transit compartment was included in PK/PD model structures. Model predictions suggested an intrapatient dose escalation of 10/30/100 μg/kg twice weekly to be selected as the starting dose in the FIH trial. However, sensitivity analyses revealed that CD123+ cell growth rate constant and maximal tumor killing rate constant were the key uncertainties to the recommended active dose. This novel translational model structure can be used as the basis to predict clinical PK/PD data for CD123-NKCE, and the translational strategy may serve as a foundation for future advancements of NKCEs.

Effect of Aspergillus flavus filtrate on different stages of Callosobruchus maculatus (Fabricius.) (Chrysomelidae: Coleoptera) on Broad beans

An experiment was conducted to use A.flavus filtrate in treating different stages of C.maculatus (eggs, larvae, pupae) after diluting it with sterile distilled water at concentrations 30%, 50%, 70% directly to calculate the killing rates after (1, 3, 5) days After treatment, the best results of egg inhibition were in the fifth day, with rates reaching 36.9, 53.7 and 83.87% respectively, and the best results of killing larvae were in the 3rd, 5th, and 5th day, respectively, with rates reaching 50.33, 80.47and 93.93% respectively, and the best results were Killing of the pupa in the 5th, 5th, and 5th day respectively, with rates that reached 63.50, 86.93and 96.97% respectively, and the best results of killing for adults were in the 3rd, 5th, and5th days respectively, with rates that reached 43.73, 90.83, and 93.93% respectively. The best results of killing were in the 1th, 3th, and 5th day respectively on adults of C. maculatus via the indirect method, as the highest killing rates were at the concentration of 70% and reached 56.83, 60.36 and 67.1% respectively, The best results were on the amount of laying eggs from an adult C. maculatus and by direct and indirect spraying on females. The results showed that the lowest rate of laying eggs for one female after three days of mating was zero eggs/female with a concentration of 70% compared to the indirect method which reached to 24.13 eggs/female.

In Vitro Eradication of Planktonic, Saliva and Biofilm Bacteria Using Lingonberry Extract as a Photosensitizer for Visible Light Plus Water-Filtered Infrared-A Irradiation

Antimicrobial photodynamic treatment (aPDT) with visible light plus water-filtered infrared-A irradiation (VIS-wIRA) and natural single- or multi-component photosensitizers (PSs) was shown to have potent antimicrobial activity. The aim of this study was to obtain information on the antimicrobial effects of aPDT-VIS-wIRA with lingonberry extract (LE) against bacteria that play a role in oral health. Planktonic bacterial cultures of the Gram-positive E. faecalis T9, S. mutans DSM20523, S. oralis ATCC 35037 and S. sobrinus PSM 203513, the Gram-negative N. oralis 14F2 FG-15-7B, F. nucleatum ATCC 25586, and V. parvula DSM, the anaerobic F. nucleatum ATCC 25586 and V. parvula DSM 2008, and the total mixed bacteria from pooled saliva and supra- and subgingival plaques of volunteers were all treated and compared. aPDT-VIS-wIRA with LE as PS significantly (p < 0.008) reduced the growth of all tested Gram-positive, Gram-negative, as well as aerobic and anaerobic bacterial strains, whereas without irradiation no reductions were seen (p < 0.0001). NaCl, with or without irradiation, was ineffective. After treatment with CHX 0.2%, the highest killing rate (100%) was observed, and no bacteria (0 log10 CFU) were cultivable. The method also significantly reduced all of the bacteria present in saliva and in the gingival biofilms. Three-dimensional visualization of viable and non-viable microorganisms revealed that LE penetrated deeper into the cell wall layers than CHX 0.2%. LE was an appropriate PS for eradicating microorganisms with VIS-wIRA, either in their planktonic form or in saliva and gingival plaque biofilms. These results encourage further investigation in order to determine which LE compounds contribute to the photosensitizing effect and to evaluate the size of the effect on maintaining oral health.

Management of the Yellow Corn Stem Borer, Sesamia cretica Led. Using Some Pesticides and Their Alternatives and Their Effect on Production Constituents of Yellow Corn Crop Zea mays in Kirkuk Governorate

Our study, the spring cultivar of the yellow corn crop was adopted in the experimental land, the aim of which was to know the best materials used in managing the corn stalk borer insect. Environmentally friendly materials were used (ash - remnants of burnt materials, in addition to table salt). In addition to our use of effective and approved pesticides in the control of stem borer in a field experiment to see the effect of the materials used on insect infestation rates It also had an effect on the killing rate of corn stalk borer larvae achieved by spraying with the experimental materials, in addition to its effect on the height of infected plants compared to the control treatmen Field surveys were conducted to find out the extent of infection with this insect in the center of Kirkuk Governorate. The experiment was repeated for the fall season 2022, with field surveys conducted for the purpose of confirming the economic importance of the insect.t. The results indicated the spread of the corn stalk borer insect in all corn-growing areas, for which tables were prepared regarding the infection rate. In the autumn season 2021 in Kirkuk Governorate. The results indicated that there was a clear effect of the materials used in the treatments, with a relative superiority of the ash and table salt treatments over the pesticide treatments (Diazinon 10% granular and Aktara EC 25).

Development of copper clad on pure titanium for an improved frictional characteristics and antibacterial properties

This study presents laser cladding of copper on commercially pure titanium surface for the first time with an aim to improve bio-mechanical and tribological performance. A thin layer of Cu metal was deposited onto cpTi substrate which offered superior control over intermixing clad with the substrate. The grain structures of the cladded region were in thermal equilibrium and exhibited cellular α-Cu refined phases at a scan velocity of 20 mm/s. The frictional coefficient of the clad metal was 25 % lower than cpTi substrate and Cu cladded CpTi metal exhibited killing rate of E.Colli cells 4 logs higher than the base metal. Moreover, the developed layer possessed a surface hardness as high as 485 Hv. The Cu cladding over bio-inert metal surface represents a promising surface engineering strategy to restrain health care associated infections more efficiently.

Interactions between alkali-activated and cement-based mortars and biofilm and their influence on microbial induced mortar deterioration

Alkali-activated fly ash (AAF) and alkali-activated slag (AAS) mortars were exposed to the sewage environment with acidophilic sulfur oxidizing bacteria and high concentration H2S to study their interaction. It was found that when they suffered the biogenic sulfuric acid attack, both the AAF and calcium aluminate cement (CAC) mortars had a strong inhibition effect on the growth and activity of microorganisms. There are more aluminum ions dissolved from AAF mortar into sewage, and its structure was characterized by the increase in 100-1000 nm pores. Still, a hard high silicon skeleton was formed to keep the apparent intact. However, CAC mortar had a higher killing rate for the bacteria in the attached biofilm. For AAS mortar, the formation of excessive gypsum increased the macropores content and was more conducive to the growth of biofilm, thereby accelerating the penetration of corrosive medium and the deterioration of mortar.

Potential side effects of the interaction between Phthorimaea absoluta parasitoids: the exotic Dolichogenidea gelechiidivoris and the native Bracon nigricans

The coexistence and efficiency in pest control of introduced and native parasitoids can be challenging. Continuous observations of the cohabitation of parasitoid species could confirm the persistence of the introduced parasitoid in the ecosystem under co-existence scenarios. This study provides an example of such a co-existence for biocontrol of the invasive pest, Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae). Two parasitoids, the introduced endoparasitoid Dolichogenidea gelechiidivoris (Marsh) (Hymenoptera: Braconidae) and the native ectoparasitoid Bracon nigricans Szépligeti (Hymenoptera: Braconidae) were released in cages containing a tomato plant infested with P. absoluta. Parasitism and killing rate of P. absoluta by both parasitoid species, and the parasitoid and P. absoluta population were monitored weekly. The parasitoid species coexisted for seven weeks in the experimental units. Parasitism by D. gelechiidivoris was significantly affected by the presence of B. nigricans, with 73% and 22% parasitism in the absence and presence of B. nigricans, respectively. Parasitism by B. nigricans was not affected by its co-existence with D. gelechiidivoris. The number of D. gelechiidivoris adults increased eight-fold in five weeks in the absence of B. nigricans, while less than the initial number of adults were present in co-existence with B. nigricans. The P. absoluta infestation declined from the fifth week to 98% lesser than the control in all the treatments, either D. gelechiidivoris or B. nigricans as standalone treatments, as well as in combination. Since B. nigricans negatively affected D. gelechiidivoris population growth, releases of this introduced parasitoid should be considered with caution in areas where B. nigricans occurs.

Efficacy of Human iPSC-Derived CAR-NK Cells Targeting Multiple Myeloma Cells

NK cells armed with chimeric antigen receptors (CAR) enable NK cells specifically to target cancer cells by recognizing tumor associated antigens. Previous studies have proven that human iPSC-derived CAR-NK cells have enhanced anti-tumor activity. Targeted B-cell maturation antigen (BCMA) therapy for relapsed refractory MM (rrMM) has been widely used with antibody-drug conjugate (ADC), bispecific antibodies, and CART cells, which has produced a rapid response, but relapse is common. Recent work has revealed GPRC5D as an alternative target in MM for immunotherapy and patients who have previously received anti-BCMA therapy have responded to GPRC5D CART cells. To assess target GPRC5D therapy with CAR-NK cells, which may in future serve as allogeneic immunotherapy, we transduced anti-GPRC5D CAR into an iPSC line derived from a healthy donor using a piggybac transposon system. More than 97% of CAR inserted-iPSCs (CAR-iPSCs) expressed anti-GPRC5D scFV with a similar expression level identified in CAR-iPSC-derived-NK cells (CAR-iNK, 92.7%). The anti-GPRC5D CAR-iNK demonstrated high purity (>99.9% for CD45 + and CD56 +) and expressed a high level of CD16 (63.6%), the NK cell activating receptor NKG2D (96.3%) and NKp30 (98.7%), and the co-stimulatory receptors CD244 (99.6%) and CD226 (97.8%). Nonetheless expression of TCR⍺β and TCRƳ- was relatively low (<2%). Cytotoxicity assay revealed that anti-GPRC5D CAR-iNK had similar cytotoxicity against K562 cells (No GPRC5D antigen) to cord blood-derived NK cells (CB-NK), wide type (WT) iNK and anti-BCMA CAR-iNK. Cytotoxicity was dose-dependent indicating that these NK cells had similar innate anti-cancer cytotoxicity. When incubated at a ratio of 4:1 with NCI-H929 cells (MM) for 4 hours, which express a high level of both BCMA and GPRC5D, anti-GPRC5D CAR-iNK demonstrated an overwhelming advantage (approximately 90% killing rate) over the CB-NK (no killing) and WT iNK (around 10% killing rate). Furthermore, the anti-GPRC5D CAR-iNK also showed superior cytotoxicity to anti-BCMA CAR-iNK (Figure 1), indicating that GPRC5D may be a more efficient target for CAR-NK-based immunotherapy in MM. We further confirmed that anti-GPRC5D CAR-NK have acceptable cytotoxicity to NCI-H929 and OPM-2 cells, even when transported over a long distance (more than 2000 km) and following cryopreservation. The lower expression by OPM-2 cells of BCMA and GPRC5D compared with NCI-H929 indicates that both fresh and cryopreserved anti-GPRC5D CAR-iNK can specifically target MM with a higher and lower expression of GPRC5D. In addition, cryopreserved anti-GPRC5D CAR-iNK cells maintain comparable antigen-specific cytotoxicity in vitro, and demonstrate the ability to reduce tumor burden in an antigen-specific manner in an OPM-2 xenograft model. Our results demonstrate that genome-engineered human iPSCs can provide an unlimited source for manufacturing scalable, off-the-shelf, and cost-effective CAR-NK cells, and GPRC5D is a potent immunotherapeutic target in multiple myeloma.

Engineering Off-the-Shelf Gamma Delta CAR T Cells for the Treatment of Acute Myeloid Leukemia

Chimeric antigen receptor T cell therapy (CART) therapy has shown remarkable success in the treatment of B cell acute lymphoblastic leukemias (B-ALL) and lymphomas. However, CART therapies for acute myeloid leukemia (AML), where 5-year survival rates are significantly lower than for B-ALL, are only in their infancy. CD33-CART have potent activity against AML in preclinical models and a first-in-child/first-in-human phase 1/2 CD33-CART clinical trial for AML is ongoing in the Pediatric Oncology Branch of the National Cancer Institute (NCT03971799). Nonetheless, published outcomes suggest a modest efficacy of approximately 50% (Shahzad et al., Front Immunol 2023), highlighting the critical need to develop new strategies to improve CART accessibility and a more robust anti-AML response. We hypothesized that off-the-shelf gamma delta (γδ) CD33 CART cells could potentially overcome current challenges for the treatment of AML. γδ lineage T cells are unconventional lymphocytes whose functions are not restricted to MHC-mediated antigen presentation; they are primed for immediate responses, including tumor killing. Furthermore, allogeneicγδ T cells have the potential to induce robust anti-tumor cytotoxicity without causing graft versus host disease (GVHD). Here, we generated γδ CAR T cells from healthy donor elutriated lymphocytes by activation with zoledronic acid and IL-2 for 7-14 days. Within 9 days post stimulation, the vast majority of lymphocytes were Vδ2+ and 30-40% were successfully transduced with a lentiviral CD33 CAR construct harboring the 4-1BB costimulatory domain. Importantly, and unlike conventional alpha beta (ab) T lymphocytes, >98% of these γδ CD33CAR T cells expressed IFNγ under basal conditions. This characteristic likely accounted for the efficient in vitro killing of AML cell lines by untransduced γδ T lymphocytes under conditions of high effector/target (E/T) ratios. While untransduced γδ T cells did not exhibit cytotoxicity following repeat AML stimulations, γδ CD33CAR T lymphocytes exhibited proficient in vitro cytotoxicity, with killing rates that were more rapid than those initiated by ab CD33 CART (Figure 1). These characteristics were associated with a prolonged metabolic activity of γδT cells; γδ CD33 CART expressed high levels of the GLUT1 glucose transporter for >14 days post activation whereas GLUT1 levels on ab CD33 CART returned to resting within 10 days. High GLUT1 levels were linked to efficient killing under conditions of basal glucose levels. Most notably, γδ CD33CAR T lymphocytes achieved high in vivo cytotoxicity, assessed using bioluminescent AML cell line xenografts in humanized NSG mice. Together, these data highlight the feasibility of generating allogeneic γδ CD33CART with a strong anti-AML cytotoxic response.

Evaluation of Telenomusremus (Hymenoptera: Platygastridae) as a biocontrol agent of Spodopteralitura (Lepidoptera: Noctuidae) based on two-sex life table and functional response analyses

BackgroundTelenomusremus Nixon is an important egg parasitoid of Spodoptera spp. pests and, as such, has potential as a biological control agent. Spodopteralitura (Fabricius) is a significant pest of many economically important crops worldwide. This study was conducted to evaluate the demographic parameters and functional response of T.remus on the S.litura eggs.ResultsT.remus can lay 186.90 eggs/female in the lifetime, adult preoviposition period was 0 days, total preoviposition period was 10.03 days, and the ratio of female and male offspring was 0.495 and 0.421, respectively. In addition, most females emerged from 24 h-old eggs, whereas most males emerged from 48 h-old eggs. The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time, and population doubling time were 0.3506 d–1 1.4199 d–1 92.45 offspring/individua, 12.91 days and 1.98 days, respectively. The net killing rate of T.remus on S.litura was 101.49 eggs/female, indicating the high capacity of T.remus to parasitize S.litura eggs. Moreover, the higher the egg density, the higher the parasitism rate by female T.remus, although there was a trend of parasitism stabilization at an egg density of 100, indicating a type II functional response curve for this parasitoid.ConclusionOverall, these findings suggest that T.remus can be efficiently reared on S.litura eggs and shows potential as biocontrol agent for this economically important pest species.

Efficacy of Oleic Acid and Linoleic Acid Vapors on the Stable Phases of Trogoderma granarium (Coleoptera: Dermestidae)

The current study is conducted with the aim of evaluating two fatty acids effectiveness and efficiency of steaming, Oleic acid and Linoleic acid, as a natural and safe alternative to chemical pesticides in controlling the hairy grain beetle Trogoderma granarium Evert fixed phases (eggs, pupae). This laboratory study included the use of four concentrations (50, 100, 200, and 150) ppm, with exposure periods that varied according to the insect role. They were (24, 16, 8) hours in the first and (36, 24, 12) hours per/2nd. The results demonstrated the treatment of insect eggs with oleic and linoleic acid vapors presenting the hatching inhibition highest rates, reaching 72.22 and 76.66% at a concentration (200 ppm) and an exposure period (24 hours), with a superior effect of linoleic acid vapor in causing inhibition rates at all concentrations and exposure used periods. The reason for the inhibition in both may be attributed to the ability of the vapor of the two acids to penetrate the egg wall and affect its protoplasm, thus thwarting the growth and development of the embryo. Also, pupae treatment with the vapor of the two acids giving the killing highest rates, reaching75.55 and 71.10, respectively, at a concentration (200 ppm) and an exposure period of (36 hours), with superiority to the effect of oleic acid vapor in killing rates at all concentrations besides using exposure periods. The cause of killing in both vapors may be ascribed to their harmful effects on the respiratory and nervous systems of the pupae, causing them to suffocate and paralyze. As for the results of the statistical analysis, they indicate the significance of each of the effects of concentrations and periods of exposure and the overlap between them to the two acids at both phases.