Enamino-oxindole HIV protease inhibitors.

We have designed and synthesized a series of HIV protease inhibitors (PIs) with enamino-oxindole substituents optimized to interact with the S2' subsite of the HIV protease binding pocket. Several of these inhibitors have sub-nanomolar K(i) and antiviral IC(50) in the low nM range against WT HIV and against a panel of multi-drug resistant (MDR) strains.

Isolation of tumor-infiltrating lymphocytes from preserved human tumor tissue specimens for downstream characterization.

Immunophenotyping of tumor-infiltrating lymphocytes (TILs) by flow cytometry can predict clinical efficacy of immunotherapy. However, several obstacles need to be overcome for developing a flow cytometry assay starting from solid tumor specimens. Here, we show a detailed enzyme-based protocol to isolate TILs from human tumor tissues. The protocol was optimized to obtain enough viable TILs from a biopsy tissue specimen for flow cytometry-based TIL immunophenotyping. Additionally, tissue samples could be preserved for up to 72 h for subsequent characterization. For complete details on the use and execution of this protocol, please refer to Kumagai et al. (2020, 2022).

Scleroderma "en coup de sabre" With Epilepsy and Uveitis Successfully Treated With Tocilizumab.

Case history of a small girl outlet with epilepsy, followed by scleroderma skin damage and uveitis, neurovasculitis with white matter foci in brain on the side of skin lesion in two months, immunologic disease activity. Resistance to conventional immunosuppressive therapy forced us to initiate the treatment with tocilizumab. It was well tolerated and led to significant improvement of brain, ocular and skin manifestations.

Novel uncomplexed and complexed structures of plasmepsin II, an aspartic protease from Plasmodium falciparum.

Malaria remains a human disease of global significance and a major cause of high infant mortality in endemic nations. Parasites of the genus Plasmodium cause the disease by degrading human hemoglobin as a source of amino acids for their growth and maturation. Hemoglobin degradation is initiated by aspartic proteases, termed plasmepsins, with a cleavage at the alpha-chain between residues Phe33 and Leu34. Plasmepsin II is one of the four catalytically active plasmepsins that has been identified in the food vacuole of Plasmodium falciparum. Novel crystal structures of uncomplexed plasmepsin II as well as the complex with a potent inhibitor have been refined with data extending to resolution limits of 1.9A and 2.7A, and to R factors of 17% and 18%, respectively. The inhibitor, N-(3-[(2-benzo[1,3]dioxol-5-yl-ethyl)[3-(1-methyl-3-oxo-1,3-dihydro-isoindol-2-yl)-propionyl]-amino]-1-benzyl-2-(hydroxypropyl)-4-benzyloxy-3,5-dimethoxy-benzamide, belongs to a family of potent non-peptidic inhibitors that have large P1' groups. Such inhibitors could not be modeled into the binding cavity of the structure of plasmepsin II in complex with pepstatin A. Our structures reveal that the binding cavities of the new complex and uncomplexed plasmepsin II are considerably more open than that of the pepstatin A complex, allowing for larger heterocyclic groups in the P1', P2' and P2 positions. Both complexed and uncomplexed plasmepsin II crystallized in space group P2, with one monomer in the asymmetric unit. The structures show extensive interlocking of monomers around the crystallographic axis of symmetry, with areas in excess of 2300A(2) buried at the interface, and a loop of one monomer interacting with the binding cavity of the 2-fold related monomer. Electron density for this loop is only fully ordered in the complexed structure.

In-use stability modeling.

Experimental design and modeling of in-use stability testing are presented in this paper. In-use open container degradation is considered in terms of time open container or/and the number of instances that the same container is used. Degradation is estimated based on two models, the fixed and the general model. The fixed model estimates in-use degradation for those fixed time points of closed container where the in-used experimental data is collected. The general model estimates in-use degradation for any time point of closed container using the estimated relationship between closed container time and the degradation rate of open container. Data for in-use open container stability does not have to be collected at a closed container time of interest to estimate in-use degradation at this time point as long as this point is within the range of the experiment. Stability of the product in terms of drift from the initial time to the time of interest is calculated as the sum of closed and in-use open containers drifts.

Scleroderma "en coup de sabre" with epilepsy and uveitis successfully treated with tocilizumab / La esclerodermia «en coup de sabre» con epilepsia y uveítis se trata con éxito con tocilizumab

Case history of a small girl outlet with epilepsy, followed by scleroderma skin damage and uveitis, neurovasculitis with white matter foci in brain on the side of skin lesion in two months, immunologic disease activity. Resistance to conventional immunosuppressive therapy forced us to initiate the treatment with tocilizumab. It was well tolerated and led to significant improvement of brain, ocular and skin manifestations

Historia de la enfermedad de una niña con epilepsia, así como las lesiones cutáneas de la esclerodermia y la uveítis, la neurovasculitis con materia blanca se centra en el cerebro en el lado de la lesión de la piel en 2 meses, la actividad de las enfermedades inmunológicas. La resistencia a la terapia inmunosupresora tradicional nos hizo comenzar el tratamiento con tocilizumab. Fue bien tolerado y condujo a una mejoría significativa en las manifestaciones cerebrales, oculares y de la piel

Utility of (His)6 tag for purification and refolding of proplasmepsin-2 and mutants with altered activation properties.

Plasmepsin-2 is a malarial aspartic proteinase that has been implicated in the initial steps of hemoglobin degradation in parasites and thus represents an attractive antimalarial target. Escherichia coli expressed proplasmepsin-2 is capable of activation at acidic pH by autocatalytic cleavage of the pro part region, which results in products of different length. We designed a 10-amino-acid deletion in the pro part region that allows faster generation of homogeneous enzyme upon activation. Incorporation of a (His)6 tag onto the N-terminus of the pro part enables on-column refolding of proplasmepsin-2 and simplifies proenzyme purification and pro part separation after activation. The proposed purification procedure results in highly pure and easily crystallizable enzyme.

Structures of Ser205 mutant plasmepsin II from Plasmodium falciparum at 1.8 A in complex with the inhibitors rs367 and rs370.

Plasmepsin II is one of the four catalytically active plasmepsins found in the food vacuole of Plasmodium falciparum. These enzymes initiate hemoglobin degradation by cleavage at the alpha-chain between Phe33 and Leu34. The crystal structures of Ser205 mutant plasmepsin II from P. falciparum in complex with two inhibitors have been refined at a resolution of 1.8 A in the space group I222 and to R factors of 19.9 and 19.5%. Each crystal contains one monomer in the asymmetric unit. Both inhibitors have a Phe-Leu core and incorporate tetrahedral transition-state mimetic hydroxypropylamine. The inhibitor rs367 possesses a 2,6-dimethylphenyloxyacetyl group at the P2 position and 3-aminobenzamide at the P2' position, while rs370 has the same P2 group but 4-aminobenzamide in the P2' position. These complexes reveal key conserved hydrogen bonds between the inhibitor and the binding-cavity residues, notably with the flap residues Val78 and Ser79, the catalytic dyad Asp34 and Asp214 and the residues Ser218 and Gly36 that are in proximity to the catalytic dyad. The structures also show unexpected conformational variability of the binding cavity of plasmepsin II and may reflect the mode of binding of the hemoglobin alpha-chain for cleavage.

A synthetic HIV-1 Rev inhibitor interfering with the CRM1-mediated nuclear export.

The HIV-1 Rev protein is an essential regulator of the HIV-1 mRNA expression that promotes the export of unspliced and partially spliced mRNA. The export receptor for the leucine-rich nuclear export signal (NES) of Rev has recently been recognized as CRM1. We identified a low molecular weight compound PKF050-638 as an inhibitor of HIV-1 Rev. This drug inhibits in a dose-dependent fashion Rev-dependent mRNA expression in a cellular assay for Rev function. We show that PKF050-638 is an inhibitor of the CRM1-mediated Rev nuclear export. By using a quantitative in vitro CRM1-NES cargo-binding assay, we could demonstrate that PKF050-638 disrupts CRM1-NES interaction. This mode of action is confirmed in cell culture because the drug reversibly interferes with the colocalization of CRM1 and Rev in the nucleolus of the cell. In addition, we prove that the inhibition is through direct interaction of the compound with Cys-539 of CRM1. These effects are similar to those of the known CRM1 inhibitor leptomycin B and suggest that the inhibitory effect of the compound is caused by binding to CRM1 at a similar site. The compound displayed strict structural requirements for its activity, as its enantiomer was inactive in all assays tested. These results show that we identified a drug that interferes with the CRM1-mediated nuclear export of Rev through inhibition of the CRM1-NES complex formation. The reversibility of its binding to CRM1 and its availability through chemical synthesis could make it useful for studying CRM1-mediated export pathways.