Emília Dvorožňáková

Immune response of mice with alveolar echinococcosis to therapy with transfer factor, alone and in combination with albendazole

The effect of dialysable leucocyte extract (transfer factor TF) on immune response of mice infected with Echinococcus multilocularis and treated with albendazole (ABZ) was observed. TF administration increased the parasite-suppressed proliferative response of T and B lymphocytes of infected mice from weeks 8 to 12 or 14 post infection (p.i.), respectively, with the most stimulative effect after TF+ABZ therapy. The CD4 T cell presence in the spleen of infected mice with TF or TF+ABZ therapy was increased from weeks 6 to 12 or 14 p.i., respectively. The production of IFN-γ (Th1 cytokine) after TF or TF+ABZ therapy was significantly higher from weeks 6 to 12 p.i., and during this time, the significantly inhibited IL-5 synthesis (Th2 cytokine) was detected, particularly after TF+ABZ therapy. The superoxide anion (O2−) production in peritoneal macrophages of infected mice treated with TF or TF+ABZ was stimulated from weeks 8 to 18 p.i. The immunomodulative effect of TF reduced the growth of larval cysts till week 14 p.i. with a comparable intensity to the anthelmintic drug ABZ. Combined therapy TF+ABZ resulted in the greatest parasite restriction and reduced the cyst development till the end of the experiment.

Kinetics of specific humoral immune response of mice infected with low doses of Trichinella spiralis, T. britovi, and T. pseudospiralis larvae

SummaryThe specific humoral immune response of the host (mouse) to the infection with low doses of larvae of encapsulating (Trichinella spiralis, T. britovi) and non-encapsulating (T. pseudospiralis) species was studied. Mice were experimentally infected with 10 muscle larvae of the parasite to simulate natural conditions of the infection in rodents, important reservoirs of trichinellosis. The low infective dose of T. spiralis and T. britovi did not evoke an increased specific IgM response, which is typical for the acute infection. Only T. pseudospiralis induced a higher specific IgM level in the intestinal phase of the infection, till day 30 p.i. The low infective dose of T. spiralis larvae stimulated a specific IgG1 production from day 20 p.i. with a strong increase on day 45 p.i., but T. britovi infection on day 60 p.i. Specific IgG1 antibodies were not detected in T. pseudospiralis infection. The production of IgG2a and IgG2b antibodies was again earlier and more expressive in T. spiralis infection from day 45 p.i., in contrast to T. britovi, where these antibodies were increased on day 60 p.i. Only IgG2b isotype was detected in T. pseudospiralis infection on days 45 and 60 p.i., however in very low values in comparison with encapsulating species.Results conclude the low infective dose of T. spiralis, T. britovi, and T. pseudospiralis induced a late seroconversion in infected mice. T. spiralis caused earlier and more intensive specific antibody response, from day 45 p.i, when antigens from newborn and muscle larvae were accumulated, on the contrary to T. britovi and T. pseudospiralis, which induced specific antibody response from day 60 p.i.

Effect of probiotic bacteria on phagocytosis and respiratory burst activity of blood polymorphonuclear leukocytes (PMNL) in mice infected with Trichinella spiralis

This study focusses on the effect of probiotic (bacteriocinogenic) strains on parasite infection and innate immunity - phagocytosis and oxidative burst of blood monocytes and polymorphonuclear leukocytes (PMNL) in mice infected with Trichinella spiralis. Bacteriocinogenic and probiotic strains of different origin (Enterococcus faecium AL41=CCM8558, Enterococcus durans ED26E/7, Lactobacillus fermentum AD1=CCM7421, Lactobacillus plantarum 17L/1) were administered daily in dose of 109CFU/ml in 100μl and mice were infected with 400 larvae of T. spiralis on 7th day of treatment. Phagocytic activity of blood leukocytes was inhibited at week 3 and 4 post infection (p.i.), i.e. in the time of massive muscle invasion with larvae T. spiralis. Administration of bacterial strains to mice prior to T. spiralis infection elevated and prolonged phagocytic activity of blood leukocytes and their ingestion capability from week 1 to 3 of the infection and the phagocytosis was inhibited only at week 4 p.i. The highest stimulative effect on phagocytosis was induced by strains E. durans ED26E/7, L. fermentum AD1=CCM7421, and L. plantarum 17L/1. The percentage of cells with respiratory burst and their enzymatic activity was increased after T. spiralis infection with the exception of week 3 p.i. In contrast, in all mice treated with bacterial strains the enzymatic stimulation was observed after the infection, with the highest intensity caused by strains E. durans ED26E/7, L. fermentum AD1=CCM7421 and L. plantarum 17L/1. The administration of probiotic strains stimulated phagocytosis and respiratory burst of blood PMNL that could contribute to a decreased larval migration and a destruction of muscle larvae and then reduced parasite burden in the host. The protective effect against T. spiralis infection was induced by all strains, but the highest reduction was recorded by E. faecium AL41=CCM8558.

Immunomodulative effect of glucan and/or glucan supplemented with zinc in albendazole therapy for murine alveolar echinococcosis

The effect of glucan immunomodulator (GI) and glucan supplemented with zinc (GIZn) administered separately or with albendazole (ABZ) on cellular immunity of mice with alveolar echinococcosis was observed. The stimulative effect of GI and GI + ABZ therapy on proliferative response of T lymphocytes was prolonged by GIZn or GIZn + ABZ from week 6 to 14 postinfection (p.i.). The increased proliferation of B lymphocytes was observed during combined therapies GI + ABZ and GIZn + ABZ from week 6 to 12 p.i. Number of splenic CD4 T cells in mice with GI or GI + ABZ therapy was increased only on weeks 6 and 8 p.i. GIZn and GIZn + ABZ therapy prolonged this stimulation from week 6 to 14 p.i. Serum concentration of interferon-γ (IFN-γ) was increased after GIZn therapy and reduced after GI therapy from week 8 to 12 p.i. GIZn + ABZ therapy had the highest effect on the IFN-γ rise from week 8 to 22 p.i. Both GI and GIZn inhibited the serum concentration of interleukin-5 (IL-5) from week 6 p.i. The production of superoxide anion was increased after GI therapy from week 6 to 14 p.i. and after GI + ABZ or GIZn + ABZ therapies from week 12 to 18 p.i. The most effective antiparasitic therapy for alveolar echinococcosis was reached by GIZn + ABZ therapy.

Trichinella spiralis reinfection: changes in cellular and humoral immune response in BALB/c mice

SummaryTrichinella spiralis infection induces a host cell-mediated and humoral response. The role of T and B lymphocytes in the immune response of mice reinfected with 2 × 400 T. spiralis larvae was studied in relation to the parasite burden. BALB/c mice were infected on days 0 and 60 and immunological parameters were examined within a period of 180 days. In comparison with a single T. spiralis infection, T- and B-lymphocytes in reinfected mice responded by a significant increase in the proliferative activity during 10 days after reinfection. At the same time, the percentages of CD4+ T-cells of reinfected mice were also increased. In contrast, the CD8+ T-cell numbers were significantly reduced almost 30 days after reinfection. High concentration of serum IFN-γ lasted till the end of the experiment. The IL-5 level was increased only for 2 weeks after reinfection, followed by its decrease. Kinetics of specific anti-Trichinella immunoglobulins IgG2a was not affected with reinfection, but specific antibodies IgG1 significantly increased after reinfection and persisted elevated till the end of the experiment. Lower numbers of adults (69.2 % reduction) in the small intestine and 72.3 % reduction in muscle larvae were found after reinfection. Stimulation of the host immune response — the increased activity of CD4+ T lymphocytes and high levels of IFN-γ and specific IgG1 after reinfection, contributed to the reduction of the parasite burden.

An invasive species as an additional parasite reservoir: Trichinella in introduced American mink (Neovison vison).

The American mink (Neovison vison Schreber, 1777) is one of the most invasive alien mammal species which has been introduced to many countries in Europe, Asia and South America. As a predator which feeds on various prey, American mink carry many endoparasites; however, data about infection rate and prevalence of different parasites in mink are limited, especially concerning Trichinella spp. The aim of our study was to evaluate the role of American mink in the circulation of Trichinella species in its introduced range. In total, 812 muscle samples of mink from six feral populations and three farms in Poland were examined for presence of Trichinella muscle larvae using the artificial HCl-pepsin digestion method. Muscle larvae were found in 27 out of 812 individuals (3.3%) from six localities in western and north-eastern Poland. The intensity of infection varied from 0.1 to 274.8 LPG. The majority of Trichinella-positive individuals - 15 (55.6%) were infected with T. britovi, one with T. spiralis, and one with T. pseudospiralis. Two animals harboured T. britovi and T. spiralis in co-infection and this data confirmed the first report of a mixed Trichinella infection in American mink.

Immune response of mice to Echinococcus multilocularis infection after therapy with amphotericin B colloidal dispersion

SummaryThe effect of amphotericin B colloidal dispersion (ABCD) on selected immunological parameters and growth of the larval cysts in mice infected intraperitoneally with Echinococcus multilocularis protoscoleces was observed. ABCD was administered at a dose 10 mg/kg body weight twice a week from week 5 to 10 post infection (p.i.). The Echinococcus infection suppressed the proliferative response of splenic T lymphocytes to nonspecific mitogen concanavalin A throughout almost the whole course of the experiment and ABCD administration did not affect this inhibittion. The increase in the proliferative response of B lymphocytes to lipopolysaccharide was found in infected mice with ABCD treatment from week 6 to 10 p.i. ABCD induced a significant rise of the splenic CD4 T cell subpopulation in infected mice only on week 6 p.i. The CD8 T subpopulation was not influenced by the therapy. The level of serum Th1 cytokine IFN-γ in infected and ABCD treated mice was elevated only at week 8 p.i., while the level of serum Th2 cytokine IL-5 was not influenced by the therapy. The ABCD treatment inhibited the IFN-γ production by splenocytes in vitro from week 6 to 10 p.i. On the contrary, the IL-5 production in vitro was stimulated at weeks 8 and 12 p.i. None antiparasitic effect of ABCD on larval growth was determined.Results suggest that amphotericin B colloidal dispersion did not affect the inhibited Th1 immune response after parasite infection. On the contrary, ABCD advanced the Th2 immune response development, which allows the progressive growth of the parasite.

Immunomodulative effect of muramyldipeptide in mice with larval toxocarosis.

Abstract The phagocytic ability of polymorphonuclear leukocytes, the metabolic activity of peritoneal macrophages, the proliferative response of T- and B-cells, and the production of specific anti-Toxocara antibodies were studied in paratenic hosts with experimental larval toxocarosis after treatment with the immunomodulator muramyldipeptide for 119 days. Peroral infection of mice with 2,500 Toxocara canis eggs partially reduced the numbers of cells and inhibited the activity of all cellular immune-response parameters studied. During most of the experiment the greatest suppression was recorded for the peritoneal-macrophage metabolic activity. Parenteral administration of muramyldipeptide to mice at two doses prior to and after infection restored and significantly stimulated the parasite-inhibited phagocytic ability of blood polymorphonuclear leukocytes, metabolic activity of macrophages, and T-lymphocyte proliferative response. It also elevated the production of specific circulating anti-Toxocara antibodies. The immunomodulator significantly reduced the count of migrating T. canis larvae in the host organism (30.6%) and decreased by half the percentage of larvae in the brain.

Differences in cellular immune responses of mice BALB/c to low and high infective doses of Trichinella spiralis

SummaryThe study was focused on a role of lymphocytes and macrophages in the immune response of mice to Trichinella spiralis infection with low (10) and high (400) infective doses of larvae. The light infection stimulated the proliferation of splenic T lymphocytes only during the intestinal phase of the infection, till day 15 post infection (p.i.), but the heavy infection activated T cells during the migration of newborn larvae (from day 20 to 30 p.i.). B cell proliferation was markedly stimulated after the heavy infection. The light infection increased the presence of helper CD4 cells till day 10 p.i. in contrast to the heavy infection, but subpopulation of CD8 T cells was not influenced by a different size of infective dose. Cytokine production of IL-5 and IFN-γ was not markedly affected by the light infection in contrast to the heavy infection that stimulated IL-5 synthesis during the whole experiment and IFN-Γ during the migration of newborn larvae. The light infection stimulated a metabolic activity of peritoneal macrophages already in the intestinal phase, but the heavy infection affected their activity only in the muscle phase of the infection.

Effect of heavy metal intoxication on macrophage metabolic activity of mice infected with Ascaris suum

SummaryThe effect of heavy metal intoxication on superoxide anion (O2−) production and larval burden during experimental Ascaris suum infection was studied. Mice were chronically intoxicated with lead (Pb), cadmium (Cd) or mercury (Hg) and subsequently infected with A. suum. The metabolic activity of peritoneal macrophages in mice intoxicated with Pb was suppressed and subsequent parasitic infection did not change this inhibition. Cd intoxication increased the superoxide production and also stimulated the activity of this oxygen radical after A. suum infection. Intoxication with Hg had a stimulative effect on the macrophage metabolic activity and subsequent A. suum infection moderately reduced this activity. Parasite burden was different depending on a type of heavy metal intoxication. Pb intoxication moderately increased the parasite burden in the liver and lungs of intoxicated mice. In contrast, Cd and Hg intoxication triggered a marked reduction of A. suum larvae in the liver and lungs of intoxicated mice, respectively. Monitored heavy metals differed in their immunomodulatory effect on metabolic activity of macrophages what also altered the intensity of the parasite infection in the hosts.