Effects of Cytokines IFN-γ and TGF-ß on the Functional Activity of Blood Mononuclear Cells against Giardia lamblia.

BACKGROUND: This study aimed to analyze cultures of mononuclear (MN) cells with Giardia lamblia to determine the levels of the cytokines IFN-γ and TGF-ß and the functional activity of MN cells after incubation with cytokines. METHODS: This study was conducted in 2018 in Barra do Garças, Mato Grosso State, Brazil. Blood samples were collected from 60 healthy volunteer donors to obtain leukocytes. The levels of IFN-γ and TGF-ß were quantified in trophozoite cell culture supernatants. Superoxide release, phagocytosis, microbicidal activity, apoptosis and intracellular calcium release were analyzed. RESULTS: The cytokines evaluated were detected in the culture supernatant of MN cells and G. lamblia. Regardless of the type of cytokine, MN cells increased superoxide release in the presence of G. lamblia. Phagocytosis, microbicidal activity and apoptosis were higher when MN phagocytes were treated with cytokines. The highest microbicidal activity and apoptosis rates were observed in MN cells cultured with TGF-ß. IFN-γ increased the release of intracellular calcium by MN phagocytes. CONCLUSION: Cytokines play a beneficial role in the host by activating MN cells against G. lamblia. In addition, phagocytosis causes G. lamblia death and that the modulation of the functional activity of blood MN phagocytes by cytokines is an alternative mechanism for eliminating G. lamblia.

In vitro immunomodulatory effects of microemulsions with levamisole delivery systems on blood phagocytes interacting with Giardia lamblia.

BACKGROUND: Giardiasis is one of the main parasites that infect the gastrointestinal tract of humans, affecting hundreds of millions of people worldwide, particularly in developing countries. Antiparasitics administered to treat giardiasis are inefficient in 20% of the cases, usually because of parasite resistance and side effects. In this scenario, microemulsions are a promising pharmaceutical alternative as carriers of molecules with therapeutic action that stimulate the immune system. METHODS: The study evaluated the effects of a microemulsion delivery system with levamisole hydrochloride on the functional activity of MN phagocytes incubated with G. lamblia. RESULTS: The microemulsion formulated was incorporated with levamisole hydrochloride using distilled water, caprylic/capric triglyceride-Polymol 812®, Sorbitan Oleate-Span 80®, Polysorbate 80 - Tween 80® and 1-butanol. The activity of the microemulsion was analyzed by phagocytosis rate, microbicidal activity, apoptosis rate and intracellular calcium concentration. Phagocytosis rate, microbicidal activity and apoptosis index increased in the microemulsion treatment. The results suggest that the microemulsion improves the therapeutic efficacy of levamisole, increasing the functional activity of phagocytes. CONCLUSIONS: The microemulsion with a levamisole delivery system is therefore an efficient alternative for treating giardiasis, acting as an immunomodulator that probably causes fewer side effects than conventional drugs.

Intracellular calcium is a target of modulation of apoptosis in MCF-7 cells in the presence of IgA adsorbed to polyethylene glycol.

PURPOSE: Clinical and epidemiological studies have indicated that breastfeeding has a protective effect on breast cancer risk. Protein-based drugs, including antibodies, are being developed to attain better forms of cancer therapy. Secretory IgA (SIgA) is the antibody class in human breast milk, and its activity can be linked to the protective effect of breastfeeding. The aim of this study was to investigate the effect of polyethylene glycol (PEG) microspheres with adsorbed SIgA on MCF-7 human breast cancer cells. METHODS: The PEG microspheres were characterized by flow cytometry and fluorescence microscopy. The MCF-7 cells were obtained from American Type Culture Collection. MCF-7 cells were pre-incubated for 24 hours with or without SIgA (100 ng/mL), PEG microspheres or SIgA adsorbed in PEG microspheres (100 ng/mL). Viability, intracellular calcium release, and apoptosis in MCF-7 cells were determined by flow cytometry. RESULTS: Fluorescence microscopy and flow cytometry analyses revealed that SIgA was able to adsorb to the PEG microspheres. The MCF-7 cells that were incubated with PEG microspheres with adsorbed SIgA showed decreased viability. MCF-7 cells that were incubated with SIgA or PEG microspheres with adsorbed SIgA had increased intracellular Ca(2+) levels. In the presence of SIgA, an increase in the percentage of apoptotic cells was observed. The highest apoptosis index was observed when the cells were treated with PEG microspheres with adsorbed SIgA. CONCLUSION: These data suggest that colostral SIgA adsorbed to PEG microspheres has antitumor effects on human MCF-7 breast cancer cells and that the presence of large amounts of this protein in secreted breast milk may provide protection against breast tumors in women who breastfed.

The effect of IFN-γ and TGF-ß in the functional activity of mononuclear cells in the presence of Entamoeba histolytica.

BACKGROUND: Entamoeba histolytica (E. histolytica) causes amoebiasis, which is a disease with significant morbidity and mortality. Phagocytic cells and cytokines appear to be important in amoebiasis, but very little is known about the influence of these cells and cytokines in protozoan infections. The aim of this study was to analyse the supernatant of cultures of mononuclear (MN) cells with E. histolytica to determine: 1) the levels of the cytokines IFN-γ and TGF-ß, and 2) the amoebicidal activity of MN cells after incubation with cytokines. METHODS: Blood samples were collected from 30 volunteer donors. The cytokine concentrations in MN cells culture supernatants, superoxide release, leukophagocytosis, amoebicide activity, intracellular calcium release and apoptosis were analysed. RESULTS: The IFN-γ concentrations were 6.22 ± 0.36 and TGF-ß concentrations were 17.01 ± 2.21 in cells-trophozoite culture supernatants. MN cells, independently of cytokines, in the presence of amoeba increase the superoxide release. In the absence of cytokines, the ingestion of MN cells by amoebae was higher. In the presence of IFN- γ or TGF- ß, a lower ingestion of MN cells was observed by amoebae. MN cells treated with cytokines exhibited higher amoebicide and apoptosis indexes. The incubation of cytokines increased the intracellular calcium release by MN cells. CONCLUSIONS: These results suggest that cytokines play a beneficial role for the host by activating MN cells against E. histolytica. The increased death of amoebae during the leukophagocytosis suggests that both cytokines (IFN-γ and TGF-ß) can modulate the functional activity of MN cells and that these cytokines probably are important in the control of amoebic infections.

Microemulsion of babassu oil as a natural product to improve human immune system function.

BACKGROUND: The aim of this study was to develop and characterize a babassu oil microemulsion system and determine the effect of this microemulsion on the functional activity of phagocytes. METHODS: The microemulsion was formulated using distilled water, babassu as the oil phase component, Sorbitan monooleate-Span 80(®) (SP), Polysorbate 80-Tween 80(®) (TW), and 1-butanol (BT). Pseudoternary diagrams were prepared, and microemulsion diagram regions were preselected. Rheological characterization and preliminary and accelerated stability tests were performed. The effect of the microemulsion on the interactions between leukocytes and bacteria was determined by superoxide release, phagocytosis, and microbicidal activity. RESULTS: The developed formulation SP/TW/BT (4.2/4.8/1.0) was classified as oil/water, showed a Newtonian profile, and had linear viscosity. When we assessed the interaction of the microemulsion or babassu oil with phagocytes, we observed an increase in superoxide, phagocytosis, and microbicidal activity. CONCLUSION: The babassu oil microemulsion system is an option for future applications, including for vaccine delivery systems. Babassu oil is a natural product, so is an alternative for future immunotherapy strategies, in particular for infectious diseases.