Synergy between Toxoplasma gondii type I ΔGRA17 immunotherapy and PD-L1 checkpoint inhibition triggers the regression of targeted and distal tumors.

BACKGROUND: In this study, we hypothesize that the ability of the protozoan Toxoplasma gondii to modulate immune response within the tumor might improve the therapeutic effect of immune checkpoint blockade. We examined the synergetic therapeutic activity of attenuated T. gondii RH ΔGRA17 strain and programmed death ligand-1 (PD-L1) treatment on both targeted and distal tumors in mice. METHODS: The effects of administration of T. gondii RH ΔGRA17 strain on the tumor volume and survival rate of mice bearing flank B16-F10, MC38, or LLC tumors were studied. We characterized the effects of ΔGRA17 on tumor biomarkers' expression, PD-L1 expression, immune cells infiltrating the tumors, and expression of immune-related genes by using immunohistochemistry, immunofluorescence, flow cytometry, NanoString platform, and real-time quantitative PCR, respectively. The role of immune cells in the efficacy of ΔGRA17 plus PD-L1 blockade therapy was determined via depletion of immune cell subtypes. RESULTS: Treatment with T. gondii ΔGRA17 tachyzoites and anti-PD-L1 therapy significantly extended the survival of mice and suppressed tumor growth in preclinical mouse models of melanoma, Lewis lung carcinoma, and colon adenocarcinoma. Attenuation of the tumor growth was detected in the injected and distant tumors, which was associated with upregulation of innate and adaptive immune pathways. Complete regression of tumors was underpinned by late interferon-gamma-producing CD8+ cytotoxic T cells. CONCLUSION: The results from these models indicate that intratumoral injection of ΔGRA17 induced a systemic effect, improved mouse immune response, and sensitized immunologically 'cold' tumors and rendered them sensitive to immune checkpoint blockade therapy.

Protective Immunity Induced by TgMIC5 and TgMIC16 DNA Vaccines Against Toxoplasmosis.

Toxoplasma gondii is an obligate intracellular parasite, which is responsible for a widely distributed zoonosis. Effective vaccines against toxoplasmosis are necessary to protect the public health. The aim of this study is to evaluate the immune efficacy of DNA vaccines encoding TgMIC5 and TgMIC16 genes against T. gondii infection. The recombinant plasmid pVAX-MIC5 and pVAX-MIC16 were constructed and injected intramuscularly in mice. The specific immune responses and protection against challenge with T. gondii RH tachyzoites were evaluated by measuring the cytokine levels, serum antibody concentrations, lymphocyte proliferation, lymphocyte populations, and the survival time. The protection against challenge with the T. gondii RH tchyzoites and PRU cysts was examined by evaluation of the reduction in the brain cyst burden. The results indicated that immunized mice showed significantly increased levels of IgG, IFN-γ, IL-2, IL-12p70, and IL-12p40 and percentages of CD4+ and CD8+ T cells. Additionally, vaccination prolonged the mouse survival time and reduced brain cysts compared with controls. Mouse groups immunized with a two-gene cocktail of pVAX-MIC5 + pVAX-MIC16 were more protected than mouse groups immunized with a single gene of pVAX-MIC5 or pVAX-MIC16. These results demonstrate that TgMIC5 and TgMIC16 induce effective immunity against toxoplasmosis and may serve as a good vaccine candidate against T. gondii infection.

Adjuvantic cytokine IL-33 improves the protective immunity of cocktailed DNA vaccine of ROP5 and ROP18 against toxoplasma gondii infection in mice.

Toxoplasma gondii is a threat for immunocompromized individuals, and no treatment is available for enhancing immunity against infection. Molecular adjuvants may improve the efficacy of DNA vaccine-induced T cell immunity. Here, we report that cocktailed DNA immunization with ROP5 and ROP18 boosted immune responses induced by a single DNA immunization with ROP5 or ROP18, but also that co-administration of molecular adjuvant IL-33 enhanced immune efficacy induced by this cocktailed DNA vaccination. These improved immune responses were characterized by higher Toxoplasma-specific IgG2a titers, Th1 responses associated with the production of IFN-γ, IL-2, IL-12, as well as cell-mediated activity with higher frequencies of CD8+ and CD4+ T cells. More importantly, this enhanced immunity has the ability to confer remarkable protection against a high dose lethal challenge of the T. gondii RH strain and thus against chronic infection with the T. gondii PRU strain. These data show that IL-33 is a promising immunoadjuvant to facilitate humoral as well as cellular immunity in a vaccine setting against T. gondii, and suggest that it should be evaluated in strategies against other apicomplexan parasites.

TITLE: La cytokine IL-33 utilisée comme adjuvant améliore l'immunité protectrice du vaccin à cocktail d'ADN de ROP5 et ROP18 contre l'infection à Toxoplasma gondii chez la souris. ABSTRACT: Toxoplasma gondii est une menace pour les individus immunodéprimés et aucun traitement n'est disponible pour renforcer l'immunité contre l'infection. Les adjuvants moléculaires peuvent améliorer l'efficacité de l'immunité des cellules T induite par un vaccin à ADN. Ici, nous rapportons que l'immunisation par le cocktail d'ADN de ROP5 et ROP18 a stimulé les réponses immunitaires induites par une seule immunisation par l'ADN de ROP5 ou ROP18, mais aussi que la co-administration de l'adjuvant moléculaire IL-33 a amélioré l'efficacité immunitaire induite par cette vaccination par cocktail d'ADN. Ces réponses immunitaires améliorées ont été caractérisées par des titres d'IgG2a spécifiques à Toxoplasma plus élevés, des réponses Th1 associées à la production d'IFN-γ, IL-2, IL-12 ainsi qu'une activité à médiation cellulaire où les fréquences des cellules T CD8+ et CD4+ étaient plus élevées. Plus important encore, cette immunité renforcée a la capacité de conférer une protection remarquable contre une provocation létale par haute dose de la souche RH de T. gondii et donc contre une infection chronique par la souche PRU de T. gondii. Ces données montrent qu'IL-33 est un immunoadjuvant prometteur pour faciliter l'immunité humorale et cellulaire dans un contexte de vaccination contre T. gondii et suggèrent qu'il devrait être évalué dans des stratégies contre d'autres parasites apicomplexes.

[Spray drying process of extract of Wenjing Zhitong Prescription based on mixture design experiment].

To improve the spray drying effect of extract of Wenjing Zhitong Prescription, this study takes the yield, hygroscopic property and the fluidity of dry powder as indexes to screen out auxiliary materials, and the proportion of the auxiliary materials was optimized based on the mixing design experiment; based on that, HPLC method was established for the determination of glycyrrhizin and 6-gingerol in spray powder, the yield of spray powder and the retention rate of the two index components were taken as indexes to further optimize the spray drying parameters. The finally selected auxiliary materials were light magnesium oxide, maltodextrin and silica, and regression equations of dry powder yield, moisture absorption rate, angle of rest with proportion of auxiliary materials were established, and the optimized proportion of auxiliary materials was dry paste-light magnesium oxide-maltodextrin-silica=0.5∶0.305∶0.145∶0.05; according to the optimized drying process parameters of Wenjing Zhitong Prescription, initial temperature was 60 ℃, air inlet temperature was 130 ℃, air flow rate was 35 m~3·h~(-1), atomizing pressure was 40 mm, and liquid inlet speed was 4.5 mL·min~(-1). Under these conditions, the dry powder yield was 90.28%, the retention rate of glycyrrhizin was 74.51%, and the retention rate of 6-gingerol was 72.10%. In this study, optimized auxiliary materials can improve the yield of spray drying and the property of spray powder, and the optimized processing conditions were good for retaining the unstable gingerol components, which can lay a foundation for the further preparation research of meridian warming and pain relieving prescriptions, and provide reference for extract of other traditional Chinese medicine extracts that are difficult to spray drying.

Palladium-Catalyzed Enantioselective C-H Olefination of Diaryl Sulfoxides through Parallel Kinetic Resolution and Desymmetrization.

The first example of PdII -catalyzed enantioselective C-H olefination with non-chiral or racemic sulfoxides as directing groups was developed. A variety of chiral diaryl sulfoxides were synthesized with high enantioselectivity (up to 99 %) through both desymmetrization and parallel kinetic resolution (PKR). This is the first report of PdII -catalyzed enantioselective C(sp2 )-H functionalization through PKR, and it represents a novel strategy to construct sulfur chiral centers.

4-(4-Nitro-styr-yl)-N,N-diphenyl-aniline.

In the triaryl-amine group of the title compound, C(26)H(20)N(2)O(2), the N atom adopts an approximately trigonal-planar geometry, lying 0.046 (5) Šfrom the plane P defined by its three neighbouring C atoms; the benzene and two terminal phenyl rings are twisted by 37.4 (1), 31.4 (1) and 47.8 (1)°, respectively from plane P. In the trans-stilbene fragment, the two benzene rings form a dihedral angle of 31.3 (1)°. In the crystal, weak inter-molecular C-H⋯O inter-actions link the mol-ecules into ribbons in [100].