Vaccination with a combination of STING agonist-loaded lipid nanoparticles and CpG-ODNs protects against lung metastasis via the induction of CD11bhighCD27low memory-like NK cells

BACKGROUND

Natural killer (NK) cells are effective in attacking tumor cells that escape T cell attack. Memory NK cells are believed to function as potent effector cells in cancer immunotherapy. However, knowledge of their induction, identification, and potential in vivo is limited. Herein, we report on the induction and identification of memory-like NK cells via the action of a combination of a stimulator of interferon genes (STING) agonist loaded into lipid nanoparticles (STING-LNPs) and cytosine-phosphorothioate-guanine oligodeoxynucleotides (CpG-ODNs), and the potential of the inducted memory-like NK cells to prevent melanoma lung metastasis.

METHODS

The antitumor effects of either the STING-LNPs, CpG-ODNs, or the combination therapy were evaluated using a B16-F10 lung metastasis model. The effect of the combined treatment was evaluated by measuring cytokine production. The induction of memory-like NK cells was demonstrated via flow cytometry and confirmed through their preventative effect.

RESULTS

The combination of STING-LNPs and CpG-ODNs tended to enhance the production of interleukin 12 (IL-12) and IL-18, and exerted a therapeutic effect against B16-F10 lung metastasis. The combination therapy increased the population of CD11bhighCD27low NK cells. Although monotherapies failed to show preventative effects, the combination therapy induced a surprisingly strong preventative effect, which indicates that CD11bhighCD27low cells could be a phenotype of memory-like NK cells.

CONCLUSION

As far as could be ascertained, this is the first report of the in vivo induction, identification, and confirmation of a phenotype of the memory-like NK cells through a prophylactic effect via the use of an immunotherapeutic drug. Our findings provide novel insights into the in vivo induction of CD11bhighCD27low memory-like NK cells thus paving the way for the development of efficient immunotherapies.

Impact of intravenous/intranasal polyinosinic-polycytidylic acid administration on the mediastinal fat-associated lymphoid clusters and lung tissue in healthy mice

BACKGROUND

Polyinosinic-polycytidylic acid (pIC) is a synthetic analog of double-stranded RNA. It is used as a synthetic adjuvant to induce an adaptive immune response. However, the effect of pIC on the development of mediastinal fat-associated lymphoid clusters (MFALCs) that regulate intrathoracic hemostasis has remained unidentified.

METHODS

We investigated the impact of intranasal (i.n.) administration (pIC i.n. group) and intravenous (i.v.) administration (pIC i.v. group) of pIC on both MFALCs and lung tissue.

RESULTS

Compared with the control phosphate-buffered saline (PBS) groups, both pIC-administered groups displayed a significant increase in the MFALC size (particularly in the pIC i.n. group), area of MFALC high endothelial venules (HEVs), area of lymphatic vessels (LVs), number of proliferating cells (particularly in the pIC i.v. group), and number of immune cells (B220+ B-lymphocytes, CD3+ T-lymphocytes, Iba1+ macrophages, and Gr-1+ granulocytes) in both MFALCs and lung tissues. In addition, a positive correlation was detected between MFALC size and proliferating cells, immune cell population, LVs, and HEVs within MFALCs in both groups. Except for the proliferating cell and B-lymphocyte populations in the i.n. administered group and granulocyte populations in both i.n. and i.v. administered routes, such correlations were significant.

CONCLUSION

In all, our data indicate that local or systemic administration of pIC induces the development of MFALCs and can be used as an immunostimulant therapeutic strategy.

Interval- and cycle-dependent combined effect of STING agonist loaded lipid nanoparticles and a PD-1 antibody

Programmed cell death 1 (PD-1) blockade combination to other drugs have attracted the interest of scientists for treating tumors resistant to PD-1 blockade. In this study, the impact of the interval, order of administration, and number of cycles of immunotherapeutic combination of stimulator of interferon genes (STING) pathway agonist loaded lipid nanoparticle (STING-LNP) and PD-1 antibody for inducing the optimal combined antitumor activity against a melanoma lung metastasis is reported. One cycle had no effect, but two and three cycles resulted in a combinedantitumor effect. The interval between the administration was found to influence the induction of the combined effect. The second and third doses increased the gene expression of the NK cell activation marker, interferon γ (IFN-γ), PD-1 and a ligand of PD-1 (PD-L1), whereas the first dose failed. NK cells in the lung showed an increase in the expression of the activation markers and PD-1 after the second dose. The combined antitumor effect of this combination therapy against melanoma lung metastasis model could be dependent on the interval as well as the number of doses of STING-LNP.These findings suggest the importance of the protocol setting when combining a nano system loaded with an immune adjuvant and PD-1 antibody.

Current strategies for different paclitaxel-loaded Nano-delivery Systems towards therapeutic applications for ovarian carcinoma: A review article

Ovarian carcinoma (OC) is one of the leading causes of death among gynecologic malignancies all over the world. It is characterized by high mortality rate because of the lack of early diagnosis. The first-line chemotherapeutic regimen for late stage epithelial ovarian cancer is paclitaxel in combination to carboplatin. However, in most of cases, relapse occurs within six months despite the initial success of this chemotherapeutic combination. A lot of challenges have been encountered with the conventional delivery of paclitaxel in addition to the occurrence of severe off-target toxicity. One major problem is poor paclitaxel solubility which was improved by addition of Cremophor EL that unfortunately resulted in hypersensitivity side effects. Another obstacle is the multi drug resistance which is the main cause of OC recurrence. Accordingly, incorporation of paclitaxel, solely or in combination to other drugs, in nanocarrier systems has grabbed attention of many researchers to circumvent all these hurdles. The current review is the first article that provides a comprehensive overview on multi-faceted implementations of paclitaxel loaded nanoplatforms to solve delivery obstacles of paclitaxel in management of ovarian carcinoma. Moreover, challenges in physicochemical properties, biological activity and targeted delivery of PTX were depicted with corresponding solutions using nanotechnology. Different categories of nanocarriers employed were collected included lipid, protein, polymeric, solid nanoemulsion and hybrid systems. Future perspectives including imperative research considerations in ovarian cancer therapy were proposed as well.

Diagnosis of Blastocystis hominis by different staining techniques

One hundred and fifty stool samples were collected from diarrheic patients of different ages, and examined for Blastocystis hominis by direct smears and concentrated by Sheather's sugar flotation. Staining was done by: Giemsa, two modifications of trichrome stain, modified Ziehl-Neelsen, safranin-methylene blue and two-auramine stains. Out of the 150 cases nine were positive for blastocystosis. The best stains were safranin-methylene blue and modified Ziehl-Neelsen stains. They had the advantage of staining cysts and amoeboid forms besides being rapid and easy to perform. The modified trichrome stains identified 8 ie, less specific and were time consuming. The auramine dyes stained the cyst, both the wall and internal body fluoresced brightly. Giemsa stain was not an efficient stain. Scanning and transmission electron microscopy (SEM, TEM) were performed to study the fine ultrastructure.

Genetical and electron microscopical studies on Cryptosporidia

The present work was to clarify whether C. parvum oocysts have different strains in human patients by using different staining, electron microscopical and genetical techniques. A trial to induce a vaccine against Cryptosporidial infection in mice was carried out using killed autoclaved Cryptosporidial oocysts. The results obtained were satisfactory. Two genotypes of C. parvum, viz: human and zoonotic genotypes were detected and described. The killed vaccine used orally gave a promising results.

In-pouch TV culture system in diagnosis of Trichomonas vaginalis infection

A newly simplified culture method, the In-Pouch TV culture system, the wet mount (WM) examination and the acridine orange stain were compared with the Oxoid culture as a standard technique in the diagnosis of trichomoniasis. Out of 70 symptomatic cases enrolled in this study, 28 specimens were positive by all methods. Among these positive specimens, 21 were positive by the Oxoid culture (75%) and 24 (85.7%) with sensitivity of 85.7% by the In-Pouch system. Both wet mount preparation and acridine orange stain had less sensitivity than the In-Pouch system (61.9%) and detected 15 (53.6%) and 16 (57.1%) of the cases respectively. The In-Pouch system has been proved to be easier in the transport and culture technique than the ordinary culture method. It alleviates the need to enter the culture, thus prevents contamination. Its cost is comparable to the ordinary culture tube. Therefore, it is recommended to use the In-Pouch culture system as a method of diagnosing trichomoniasis.

Effect of ozone on the viability of some protozoa in drinking water

Water samples from household tanks in several districts of Alexandria, were examined for protozoa contamination and study to the effect of ozone and chlorine on their viability. The parasitic protozoa encountered were Giardia (56%), Cryptosporidia (50%), Blastocystis (12%), Cyclospora (9%) and Microsporidia (3%). Distilled water was treated by ozone or chlorine. Ozonated-water samples were prepared at a concentration of 1 ppm after contact times with ozone of three, five, seven and nine minutes. Chlorine concentrations were 4 and 8 ppm. Parasites were incubated overnight at room temperature with the treated distilled water. Viability of the parasites was assessed by examining intestinal sections of infected animals. The best results were obtained by using ozonated water after a contact time of nine minutes. Giardia, Cryptosporidia and Microsporidia were completely inactivated, while infectivity of Cyclospora and Blastocystis was markedly reduced. It is suggested that ozone at an appropriate concentration inactivate pathogenic protozoa in water.

A comparison between human, crustacean and bivalve isolates of Microsporidia

Identification of Microsporidia detected in diarrhoeic stool of human and from press preparation of crabs, and bivalves muscles was done by staining with Giemsa, modified trichrome and H & E stains respectively. Positive samples were isolated & used for infection of 3 groups of mice viz group A human isolate, group B crab & group C bivalve isolates. Parasitological and histopathological studies using light and transmission electron microscopy (TEM) were done for samples from each group. The results clarified that human, crab & bivalve Microsporidia isolates showed common features. They were found in the supranuclear region of enterocytes. The stages observed were meronts, sporonts and free spores. Each spore was 1-2 um in length containing a single nucleus, a vacuole and a polar filament. Further genetical and biochemical studies will be undertaken to confirm the similarity or differences between these isolates.

Coccidial infection in immunosuppressed mice: prophylaxis and treatment with dehydroepiandrosterone

Cryptosporidiosis and toxoplasmosis are diseases caused by opportunistic coccidial parasites that can lead to life-threatening infection in immunocompromised patients. We evaluated dehydroepiandrosterone as prophylaxis and therapy in immunosuppressed mice infected with Cryptosporidium parvum and avirulent Toxoplasma gondii. Mice were infected with either Cryptosporidium oocysts or Toxoplasma cysts. Assessment was by mortality rates, parasitic counts and electron microscopic studies. Mortality rates were significantly reduced in all treated groups. A significant reduction in the cryptosporidial oocyst count in stool and intestinal villi and in Toxoplasma cysts in the brains of infected mice was observed in all the groups. The effect of the drug was greater when given prior to infection.

Detection of Cryptosporidium parvum antigen by co-agglutination test and ELISA

Confirmation of the presence of Cryptosporidium in environmental samples is laborious, costly and often difficult. We report here a simple and economic slide agglutination test (co-agglutination test) for detecting cryptosporidial antigen in stool, serum and water. The results show that as a screening method co-agglutination is clearly superior to enzyme-linked immunosorbent assay (ELISA) and modified Ziehl-Neelsen staining, although ELISA is more accurate. The co-agglutination test is recommended for application as a new tool for detecting cryptosporidial antigen in large-scale epidemiological surveys.

Electroencephalographic changes in rats received antigens of different parasites

The prevalence of epilepsy in developing countries is much higher than in developed ones. Some of the highest prevalence rates in developing countries have been reported from tropical Africa where parasitic infections are endemic. This work was carried out to assess the effect of different parasitic antigens on the activity of cerebral cortex in rats. Nine crude antigens were used: Adult Fasciola, adult S. mansoni, hydatid cyst, T. spiralis, E. histolytica, Acanthamoeba spp. G. lamblia, Cryptosporidium spp. and crude antigen of T. gondii. All the parasitic antigens induced electroencephalographic changes compared with baseline tracings.

Detection of Cryptosporidia in different water sources in Alexandria by monoclonal antibody test and modified Ziehl Neelsen stain

Cryptosporidium paruum has become one of the most important contaminant found in drinking water and is associated with high risk of waterborne diseases particularly for the immunocompromised. In the present study, Cryptosporidium was found in uncovered water tanks, nearby the shore in El Noubareya and El Mahmoudeya canals and in one swimming pool. Direct flourescence monoclonal antibody was more sensitive in detecting the organism. Ziehl-Neelsen although less sensitive, yet it has the advantage that it could recognize other protozoa causing diarrhoea as G. lamblia, B hominis and Cyclospora sp.

Aminosidine sulphate in experimental giardiasis

Giardia lamblia infection may be asymptomatic or may produce diarrhea with or without malabsorption. Many drugs were used for treatment of giardiasis, but none proved to be ideal since all have potential troublesome side effects as they are absorbed from the intestine. In this study, a locally acting drug aminosidine-sulphate (gabbroral) has been tried in treatment of experimental giardiasis in a rat model under different conditions of gastric acidity which is one of the main local factors affecting the pathogenicity of the organism. The best results were obtained in the group with hyperacidity which was induced by indomethacin (indocid) with significant improvement in the pathological picture and parasitic count. While in experimental animals with normal acidity there was only partial eradication of the parasite. However, in the group with hypoacidity induced by cimetidine (cimetex), the drug showed no beneficial effects since most organisms invaded the deeper layers of the intestine escaping the local action of the drug.

Aminosidine sulphate in experimental cryptosporidiosis

The present study aimed at investigating the efficiency of a recent antibiotic Aminosidine sulphate (Gabbroral) in experimental cryptosporidiosis. The course of infection was studied when the drug was given early before the infection, and late during the infection both parasitologically and histopathologically. When the drug was given early, the results were satisfactory, with a significant reduction of size, number and pathological changes of the parasites in the stool and in ileal sections of infected mice. However, the drug had no effect when given late during the infection.

A study on experimental cryptosporidiosis

Cryptosporidium oocysts were isolated from stools of infected patients diagnosed as cryptosporidiosis. Suckling Swiss albino mice were infected orally by these oocysts in a dose of 10(6) oocysts/mouse. Mice were divided into 9 groups according to the duration of infection 2, 3, 4, 5, 6, 7, 10, 10, 15, 21 days postinfection, corresponding non infected control groups were included. Stools of infected mice were examined twice daily to determine; infection rate, prepatent period and intensity of infection. Mice were sacrificed according to the schedule and the whole intestine was isolated and processed for histopathological examination by H & E and modified Ziehl Nielsen stain, and histochemical examination for acid and alkaline phosphatase activity. The results revealed that the infection rate was 90% and prepatent period 3-5 days and the course of infection was 21 days. The maximum pathological changes were in the ileum. These changes were reversible.

Contraception and community in Egypt: a preliminary evaluation of the population/development mix

Egypt's Population and Development Program (PDP) is an effort to combine family planning and development approaches at the grass roots level. Introduced as a pilot project in the late 1970s, it is now active in nearly three quarters of Egypt's villages. A 1980 Contraceptive Prevalence Survey of over 5,000 rural women stratified 124 villages according to their exposure to the program (from zero to two or more years). Comparison of women living in villages of varying exposure revealed no differences in fertility; but modest differences in knowledge, attitudes, and contraceptive practice were apparent, especially in Upper Egypt. A multivariate analysis with socioeconomic and demographic controls did not weaken these relationships. Moreover, program effects were most marked among those most in need of services--noncontracepting fecund women who were illiterate.

Turbulence measurements with pulsed Doppler ultrasound employing a frequency tracking method

A phase lock loop method of tracking doppler ultrasound frequencies is applied to the measurement of turbulent velocities. A pulsed Doppler ultrasound system capable of detecting two velocity components was employed to resolve axial and radial velocity components at the centerline of turbulent pipe flows and distal to stenoses in pulsatile flow. Measurements with the ultrasound system are compared with laser Doppler and hot film anemometer data. The results demonstrate that the phase lock loop method of tracking accurately follows turbulent velocity fluctuations for turbulence intensities up to approx. 20%, after which signal dropout becomes a significant factor. An important application of the method is that of detecting flow disturbances created by mild to moderate degrees of stenosis in arterial disease.

The influence of wife's education on fertility in rural Egypt

Based on survey data from rural Egypt, the effects of the wife's education on fertility and family planning were investigated and shown to be very important. In accordance with the results of most other studies, there is an inverse relationship with the number of live births. The wife's education is also shown to influence attitudes towards family size, spacing, and knowledge and approval of contraceptives, all of which lead to a high proportion of contraceptive use and help to achieve the desired family size. There was also a clear inverse association between the wife's education and pregnancy loss and infant mortality; these latter two variables showed positive correlations with the number of live births.

(Summary in Arabic on p. 60)