Echinococcosis is an almost cosmopolitan zoonosis caused by adult or larval stages of tapeworms (
Several approaches, aiming to improve the outcome of therapy are under investigation. For example, combining the two drugs with different mode of action, such as praziquantel and albendazole (Skuhala
Dialyzable leukocyte extract (DLE), available under the commercial name IMMODIN (ImunaPharm, Ltd. Slovakia) is the cell homogenate prepared from desintegrated blood leukocytes of healthy human donors. In our previous studies we have shown that this type of DLE administered as an adjuvant to ABZ enhanced the drug´s efficacy via stimulation of Th1 and attenuation of Th2/Treg biased immune responses in mice infected with model metacestodes of
The present study was undertaken to compare the effects of DLE (IMMODIN) on systemic cellular immunity in blood and spleen after different routes of administration as well as on the reduction of
Infection with metacestode
For total leukocyte count a blood sample dilution 1:20 in Türk solution was prepared and cells were counted using an optical microscope Olympus BX51 (Japan) in s Bürker counting chamber. The final counts for 1 ml were calculated by multiplication by 10 times.
In vitro phagocytic activity was determined using the Phagotest kit (BD Biosciences, San Jose, CA, USA). The principle of the test is that whole blood is incubated with opsonized (by complement and immunoglobulin)
We analyzed the proportions of lymphocyte subpopulations, myeloid cells subpopulations, including eosinophils in the peripheral blood. Fifty microliters of heparinized blood were plated into a round bottom tube and stained with monoclonal antibodies for 30 minutes at room temperature in dark. Then cells were fixed with BD FACS Lysing Solution (BD Biosciences, San Jose, CA, USA), washed with PBS and resuspended in 100 μl of FACS buffer. Samples of blood cells were stained with monoclonal anti-mouse antibodies CD3-FITC (clone 17A2) and CD45R (B220, clone RA3-6B2) which were analyzed from lymphocyte population determined by forward and side scatter. Other samples were stained with antibodies to CD3-PerCTeFluor710 (clone C 17A2), CD4-FITC, (clone GK1.5) and CD8a-PE (clone 53–6.7). Myeloid sub-populations were detected using antibodies to CD45.2 PE-Cyanine 7 (clone 104), CD11b-FITC (clone M1/70), MHCII-PE Cyanine 7 (clone M5/114.15.2) and CD170 SiglecF-PerCPeFluor 170 (clone 1RNM44N). The analyses were performed on BD FACS Canto (Becton Dickinson Biosciences) flow cytometer.
Suspensions of splenocytes were prepared by the method described previously (Mačak Kubašková
The suspensions of lymphoid spleen cells from naive and infected/ treated mice were diluted to the concentration of 2×106 cells/ml in CM and plated (200 μl/well) into 96-well plates (Corning. Inc., USA) in triplicates for unstimulated and Con A (3 μg/ml) stimulated T lymphocytes and LPS (1 μg/ml) stimulated B lymphocytes. After incubation for 52 h at 37 °C and 5 % CO2, the BrdU solution was added to the cell suspensions at 5 μM final concentrations (BrdU ELISA cell proliferation kit, Roche Diagnostics GmbH, Mannheim, Germany). Cells were further incubated for 18 h, then were centrifuged at 360
Samples of the lymphoid population from spleens diluted to 2×106 cells/ml in CM were plated and stimulated by Con A as is described for BrdU proliferation assay. After 70 hrs of incubation plates were centrifuged as described previously and supernatants were collected and stored at -20 °C until used for determination of cytokine production. The concentration of cytokines interferon gamma (IFN-γ), interleukin-4 (IL-4) and transforming growth factor beta (TGF-β) were determined by ELISA kits (eBioscience, Thermo Fisher Scientific, USA). Results were expressed in pg/ml.
Total RNA from lymphoid spleen cells was extracted with Ribo-ZolTM RNA Extraction Reagent (Invitrogen, Carlsbad, CA, USA) after homogenization in Tissue lyzer (Qiagen, USA) for 30 sec. The concentration and purity of RNA were determined using AstraGene spectrophotometer (Harston, Cambridge, UK). After that, 3 μg of total RNA/sample was reverse-transcribed to produce cDNA utilizing RevertAid H Minus M-MuLV Reverse Transcriptase, 100 pmol of oligo dT primers and the reaction included 20 U of RNase inhibitor and 1mM dNTPmix (final) (all from ThermoScientific, Burlington, ON, Canada). In the present study the mRNA levels of IFN-γ, TGF-β, IL-4 and corresponding cytokine transcription factors T bet, GATA3 and FoxP3 were determined. GAPDH (glyceraldehyde-3-phosphate dehydrogenase) was used as the house-keeping gene. The list of primers is summarised in Table 1. In the qPCR reactions cDNAs served as templates using iQ SYBR green master mix (BioRad, Hercules, CA, USA) and oligonucleotides pairs for individual genes. The reactions were run in duplicates on CFX96 thermocycler (BioRad, Hercules, CA, USA).
List of oligonucleotides and their sequences.
Gene | Orientation | Sequence |
---|---|---|
GAPDH | forward | 5′-AGGTCGGTGTGAACGGATTTG-3‘ |
IFN-γ | forward | 5′-TCAAGTGGCATAGATGTGGAAGAA-3‘ |
TGF-β | forward | 5′-TGACGTCACTGGAGTTGTACGG-3′ |
IL-4 | forward | 5′-TCAACCCCCAGCTAGTTGTC-3′ |
FoxP3 | forward | 5′-AATAGTTCCTTCCCAGAG-3′ |
T-bet | forward | 5′-GCCAGGGAACCGCTTATATG-3′ |
GATA3 | forward | 5′-GAAGGCATCCAGACCCGAAAC-3′ |
Melting-curve analysis was used to confirm amplification of the single product. Ct values were normalized to Ct values for the housekeeping gene and relative gene expression was calculated by the 2-ΔΔCt method using data for healthy mice as calibration value.
To measure the production of nitric oxide (NO) by adherent myeloid cells from spleens, cell suspensions (1 × 106 cells/ml) were cultured in 24-well plates in duplicates (Corning) in CM in the presence or absence of lipopolysaccharide (LPS) at the concentration of 1 μg/ml. The plates were incubated for 72 h at 37 °C and 5 % CO2. Immediately after assay termination, the concentration of NO in the culture supernatants was determined as nitrite (NO2-) using Griess reagent. Briefly, 50 μl of a solution containing 1 % sulphanilamide and 5 % H3PO4 was incubated with 50 μl of supernatants in a 96-well plate for 10 min at room temperature. Subsequently, 50 μl of a second solution (0.1 % N-(1-naphthyl) ethylenediamine dihydrochloride) was added to the mixture and the absorbance was measured at 550 nm using ELISA reader. Nitrite concentration was determined from the standard curve of 0.1 M NaNO2 dilutions run in parallel with samples. After that, cells were lysed with lysis solution (0.1 % NaOH, 0.1 % Triton-X100) overnight at 4 °C and used to determine cell proteins with Bradford protein reagent (Bi-oRad, Hercules, CA, USA). Finally amount of NO was calculated for 1 mg of cell proteins.
All data were calculated as mean ± standard deviation (SD). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post-hoc test. Data were evaluated by GraphPad Prism (version 7) (GraphPad Software, Inc., San Diego, CA, USA) and the differences were considered significant at p < 0.05.
The effect of DLE treatment administered intraperitoneally (IP), subcutaneous (SC) and per os (PO) was compared with untreated mice and the mean weights of parasite cysts are shown in Figure 1. The significantly lower weight of parasite cysts was found in PO- treated group compared to the untreated control (p < 0.01). The slight nonsignificant reduction was seen after SC and IP application of DLE.
Fig. 1
The effects of DLE administration by PO, SC and IP routes on the parasite cysts weights in the peritoneal cavities of infected mice. The numbers represent means ± SD of (n = 5 mice/ group). Significantly different values between infected and treated mice are indicated by connecting line, **p < 0.01.

The total numbers/ml of leukocytes in INF (p < 0.01), PO (p < 0.05) and SC-treated (p < 0.01) groups were lower than in the healthy control group (Fig. 2A). The IP administration of DLE had no significant effect on total white blood cell counts in infected mice. We then analyzed changes in the proportions of subpopulations of leukocytes by flow cytometry and total counts were then calculated for white blood cells (Table 2). The infection resulted in the reduction of total lymphocytes in blood (Fig. 2B) and administration of DLE partially restored their proportions, the most after PO application (p < 0.05). The representative dot plot is shown in Fig. 2C. In comparison with healthy mice the proportions of CD3+ T lymphocytes were elevated in infected untreated mice (79.1 ± 2.4 %) (p < 0.001) and treated mice (Fig. 3A). PO route of DLE administration decreased the proportions of CD3+T cells (p < 0.01) when compared to infected group. The opposite trend was observed in the proportions of B220+ B lymphocytes for all infected groups (Fig. 3B) which declined significantly (p < 0.001) compared to healthy mice (40.3 ± 3.6 %). PO given treatment resulted in the elevation (29.1 ± 2.9 %) (p < 0.001) compared to infected untreated group (18.8 ± 2.3 %). Examining the DLE effect on lymphocyte subpopulations, CD3+T lymphocytes were gated on CD4+T helper cells (Fig. 3C) and CD8+ cytotoxic T cells (Fig. 3D). Compared to healthy mice proportions of CD4+ lymphocytes were lower in infected untreated mice (70.8 ± 4.7 %) (p < 0.01) and DLE administration did not influence their proportions. The proportions of CD8+T lymphocytes were significantly higher in infected group (p < 0.001) compared to the healthy control (Fig. 3D) and were diminished after PO and IP routes (p < 0.05) as compared to the infected untreated group. The gating strategy (representative dot plots) for analysis of lymphocytes subpopulations is shown in Fig. 3 E-G.
Fig. 2 A-B
The effects of DLE administration by PO, SC and IP routes on:

Fig. 3 A-D
The proportions of lymphoid cells subpopulations in the peripheral blood of control, infected and infected and treated mice were analyzed by flow cytometry.

The total numbers of white blood cell subpopulations in 1 ml of peripheral blood.
Routes of DLE administration | |||||
---|---|---|---|---|---|
Groups of mice/ cell subpopulations | CTRL | INF | PO | SC | IP |
White blood cells | 8.72 ± 1.17 | 6.10 ± 0.46 | 7.02 ± 0.82 | 5.65 ± 0.67 | 7.06 ± 1.05 |
Lymphocytes/WBC | 5.86 ± 0.94 | 1.79± 0.55 | 3.54±0.67 | 2.61±0.46 | 2.66 ± 0.49 |
CD3+/lymphocytes | 3.41 ± 0.62 | 1.41 ± 0.43 | 2.42 ± 0.51 | 2.02 ± 0.38 | 2.04 ± 0.23 |
B220+/lymphocytes | 2.33 ± 0.29 | 0.34 ± 0.13 | 1.03 ± 0.24 | 0.56 ± 0.09 | 0.52 ± 0.11 |
CD11b+/WBC | 3.71 ± 0.71 | 4.21 ± 0.55 | 4.55 ± 0.85 | 3.95 ± 0.43 | 5.23 ± 0.99 |
* Legend: Lymphocytes and CD11b+ cell subpopulations were calculated from total white blood cell numbers based on their proportions determined by flow cytometry. Counts of T lymphocytes (CD3+) and B lymphocytes (B220+) were calculated from subpopulation of lymphocytes.
The DLE effect on the innate immune cells was studied by means of the phagocytosis of blood neutrophils and monocytes (Fig. 4A). Phagocytic activity (PA) was measured as the average number of fluorescein-labelled
Fig. 4 A-B
The effects of DLE administration on the

Myeloid-derived populations of white blood cells were evaluated using antibodies to CD11b, which is part of the surface complement receptor detected on monocytes, macrophages, NK cells, granulocytes, mostly neutrophils and on some populations of eosinophils during inflammation (Stevens
Fig. 5 A-F
Phenotypic analysis of myeloid-derived populations in peripheral blood of mice was performed by flow cytometry. Cells in control, infected and infected and treated mice were gated on

The proportions of lymphoid and myeloid sub-populations in the suspensions of splenocytes was evaluated by flow cytometry by means of FSC and SSC analysis. Similarly, as in the case of the lymphoid population in blood, we observed the significant decrease of lymphoid cells (33.17 ± 6.5 %) in infected mice compared to the healthy group (p < 0.001). Of all three administration routes, only PO given DLE attenuated significantly (p < 0.01) suppressive parasitic effect on lymphocyte proportions (46.01 ± 4.3 %) (Fig. 6A). However, the behaviour of the myeloid population following therapy showed the opposite trend (Fig. 6B) and the proportions found in the infected untreated group (68.12 ± 7.0 %) declined after PO therapy (53.4 ± 4.4 %) (p < 0.05).
Fig. 6
The proportions of:

T and B lymphocytes were separated from myeloid cells after their adherence on the plastic surface and used to examine proliferation ability
Fig. 7 A-B
The proliferation index of:

Production of cytokines by T cells from all groups was examined in the supernatants of Con A stimulated lymphocytes after 70 h of incubation
Fig. 8 A-C
The production of cytokines by Con A stimulated T lymphocytes isolated from the spleens of control, infected and infected and treated mice

We next studied the effect of infection and DLE on IFN-γ, IL-4 and TGF-β cytokines and transcription factors T bet (Th1), GATA (Th2) and FoxP3 (Treg) on mRNA levels, which are essential for T helper cells differentiation. Data summarizing relative gene expression are shown in Fig. 9A-F. The activity of the gene encoding IFN-γ was very low in the untreated group, whereas PO (p < 0.001) and SC routes of therapy (p < 0.01) stimulated this gene expression. The similar pattern of gene expression was found for T bet. On the contrary, mRNAs encoding Th2 type cytokine IL-4 and transcription factor GATA were upregulated in infected group compared to healthy mice. Suppression of gene expression for IL-4 in splenic unstimulated lymphocytes was found after all three routes of DLE administration (p < 0.001), the most after PO therapy. However, GATA expression was down-regulated only after PO and SC administration. IP administration resulted in the GATA elevation (p < 0.05) in comparison with infected mice. Transcripts of TGF-β cytokine involved in Treg immunity as well as the corresponding FoxP3 factor were strongly elevated in infected group (p < 0.001). Significant downregulation of both genes was found after PO and SC administration of DLE. However, IP therapy was unable to abolish the infection - induced elevated transcription of TGF-β and FoxP3 in spleen lymphocytes.
Fig. 9 A-F
Relative m-RNA expression of cytokines IFN-γ, IL-4 and TGF-β and corresponding transcriptions factors T bet, GATA3 and FoxP3 (shown as the fold change) was examined by qRT-PCR in the samples of unstimulated lymphocytes isolated from the spleens of control, infected and infected and treated mice. Relative gene expression was calculated by 2-ΔΔCt method using data for control healthy mice as calibrator following normalisation to GAPDH. Data are expressed means ± SD of duplicates/mouse/group. Significantly different values between infected and treated mice are indicated by connecting line, *p < 0.05, **p < 0.01, ***p < 0.001.

Next, we examined the NO production by the enzyme iNOS, which utilizes L-arginine as a substrate and competes for the same substrate with arginase. Adherent splenocytes were incubated for 72 h
Fig. 10
The concentration of NO determined in the culture supernatants of LPS-stimulated adherent myeloid cells (1x106) isolated from the spleens of control, infected and infected and treated mice

The infection of the intermediate hosts by the metacestodes stage of
In the present study we investigated immunomodulatory effects of human DLE (IMMODIN) consisting of biologically active mixture of small protein and non-protein molecules after three routes of administration to the Balb/c strain of mice with
In present study when compared to untreated group, a significant reduction of peritoneal cyst weight was found after per os application of nine DLE doses. Subcutaneous and intraperitoneal routes reduced parasite cyst growth only moderately. In the patients with echinococcosis, therapy outcome is routinely evaluated by white blood cell proportions, cytokines, chemokines and other markers. To explain the observed outcome of DLE administration after different routes we evaluated the effect on white blood cells and splenocytes as these compartments interact closely with each other (Bronte
Significant PO-stimulated proliferation of T cells observed in our study correlated with the highest reduction of cyst weight in the peritoneal cavities, suggesting that this route was the most effective in the activating antiparasitic Th1-biased CD4+ T cell subsets. LPS stimulates proliferation of B lymphocytes via the TLR4 receptor and we observed the significantly higher proliferative response after PO and IP administration compared to infected mice. Dvorožňáková
Cytokines are the key players in the process of naïve lymphocyte polarization. In
We showed here that the production of the canonical cytokine of Th1 type of immunity IFN-γ was increased by lymphocytes from infected mice compared to healthy mice. DLE given by SC and IP routes significantly reduced concentrations of this cytokine, while PO route resulted in considerably higher concentrations. The similar pattern was observed on mRNA levels for IFN-γ and T bet genes. IL-4 cytokine concentrations and mRNA levels were highly upregulated in infected mice and DLE strongly reduced this Th2 dominant cytokine after all three routes. However, mRNA expression of GATA3 factor was upregulated after IP route, but not after SC and PO routes. In AE patients Ma
Immunosuppression induced by metacestodes of
In conclusion, the results of present study indicate that the kinetics of intestinal absorption of molecules in DLE after PO administration in the course of
Fig. 1

Fig. 2 A-B

Fig. 3 A-D

Fig. 4 A-B

Fig. 5 A-F

Fig. 6

Fig. 7 A-B

Fig. 8 A-C

Fig. 9 A-F

Fig. 10

List of oligonucleotides and their sequences.
Gene | Orientation | Sequence |
---|---|---|
GAPDH | forward |
5′-AGGTCGGTGTGAACGGATTTG-3‘ |
IFN-γ | forward |
5′-TCAAGTGGCATAGATGTGGAAGAA-3‘ |
TGF-β | forward |
5′-TGACGTCACTGGAGTTGTACGG-3′ |
IL-4 | forward |
5′-TCAACCCCCAGCTAGTTGTC-3′ |
FoxP3 | forward |
5′-AATAGTTCCTTCCCAGAG-3′ |
T-bet | forward |
5′-GCCAGGGAACCGCTTATATG-3′ |
GATA3 | forward |
5′-GAAGGCATCCAGACCCGAAAC-3′ |
The total numbers of white blood cell subpopulations in 1 ml of peripheral blood.
Routes of DLE administration |
|||||
---|---|---|---|---|---|
Groups of mice/ cell subpopulations | CTRL | INF | PO | SC | IP |
White blood cells | 8.72 ± 1.17 | 6.10 ± 0.46 | 7.02 ± 0.82 | 5.65 ± 0.67 | 7.06 ± 1.05 |
Lymphocytes/WBC | 5.86 ± 0.94 | 1.79± 0.55 | 3.54±0.67 | 2.61±0.46 | 2.66 ± 0.49 |
CD3+/lymphocytes | 3.41 ± 0.62 | 1.41 ± 0.43 | 2.42 ± 0.51 | 2.02 ± 0.38 | 2.04 ± 0.23 |
B220+/lymphocytes | 2.33 ± 0.29 | 0.34 ± 0.13 | 1.03 ± 0.24 | 0.56 ± 0.09 | 0.52 ± 0.11 |
CD11b+/WBC | 3.71 ± 0.71 | 4.21 ± 0.55 | 4.55 ± 0.85 | 3.95 ± 0.43 | 5.23 ± 0.99 |
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