Immune response to Trichomonas vaginalis. IV. Immunochemical and immunobiological analyses of T. vaginalis antigen

The immune response of patients with trichomoniasis vaginitis to Trichomonas vaginalis was examined by using passive hemagglutination assay and skin reactions. Trichomonas-specific immune responses could hardly be detected in the patients by these assay methods. In order to develop a simple and reliable assay for demonstration of T. vaginalis-specific immune responses in the patients, proliferation responses of peripheral mononuclear cells from the patients were examined. Lymphocytes obtained from the patients were shown to incorporate 3H-methyl-thymidine when stimulated with T. vaginalis antigen in vitro. Furthermore, immunochemical analysis of T. vaginalis antigen has been done by Sephadex chromatography and sodium dodecyl sulfate gel electrophoresis. The data revealed that the murine and human IgM antibodies specific to T. vaginalis recognize various antigens with a wide range of molecular weights (between 13,000 and 100,000 daltons), while human and murine IgG antibodies recognize molecules with a much narrower range of molecular weights (50,000-100,000 daltons).     

Antigen-specific proliferation responses of peripheral blood lymphocytes to Trichomonas vaginalis antigen in patients with Trichomonas vaginitis.

This report describes the development of an assay system which overcomes the difficulty of detecting immune responses of patients with Trichomonas vaginitis by making use of peripheral blood leukocytes obtained from such patients. When peripheral blood leukocytes from the patient were stimulated in microcultures with the soluble antigen extracted from Trichomonas vaginalis, significant degrees of proliferation ensued, as measured by the incorporation of [methyl-3H]thymidine 4 to 5 days after initiation. The antigen-induced proliferation response of peripheral blood leukocytes is specific for T. vaginalis antigen. The T. vaginalis-specific [methyl-3H]thymidine incorporation is mediated by Leu-1-positive cells, namely, T lymphocytes, in the peripheral blood leukocyte population. This assay system should prove useful for the analysis of the immune response to the protozoa in patients with Trichomonas vaginitis.     

Toxoplasma gondii infection inhibits the development of lupus-like syndrome in autoimmune (New Zealand Black x New Zealand White) F1 mice

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of autoantibodies and lupus nephritis. In the present study using New Zealand Black (NZB) x New Zealand White (NZW) F1 (NZBW F1) mice, we planned to investigate the effects of Toxoplasma gondii infection on the progress of lupus nephritis. Female NZBW F1 mice at the age of 2 months were perorally infected with T. gondii. The T. gondii infection reduced the number of mice developing proteinuria and immune complex deposits in their kidneys and prolonged their life span. A marked decrease in the levels of IgM and IgG anti-DNA antibodies, especially IgG2a and IgG3 subclasses, was observed in T. gondii-infected NZBW F1 mice at 9 months of age. The level of anti-HSP70 IgG autoantibody in the sera of NZBW F1 mice was significantly higher than that in control mice at 9 weeks after T. gondii infection. Moreover, NZBW F1 mice treated with anti-self heat shock protein 70 (HSP70) monoclonal antibody were substantially protected against the onset of glomerulonephritis. Further, down-regulation of intracellular expression of IFN-gamma and IL-10 was shown in spleen cells of T. gondii-infected NZBW F1 mice. This was consistent with the previous data indicating the involvement of Th1-type and Th2-type cytokines in the development of lupus-like nephritis. These results suggest that T. gondii infection is capable of preventing the development of autoimmune renal disorder in NZBW F1 mice.     

TLR2 as an essential molecule for protective immunity against Toxoplasma gondii infection

To investigate the role of the Toll-like receptor (TLR) family in host defense against Toxoplasma gondii, we infected TLR2-, TLR4- and MyD88-deficient mice with the avirulent cyst-forming Fukaya strain of T. gondii. All TLR2- and MyD88-deficient mice died within 8 days, whereas all TLR4-deficient and wild-type mice survived after i.p. infection with a high dose of T. gondii. Peritoneal macrophages from T. gondii-infected TLR2- and MyD88-deficient mice did not produce any detectable levels of NO. T. gondii loads in the brain tissues of TLR2- and MyD88-deficient mice were higher than in those of TLR4-deficient and wild-type mice. Furthermore, high levels of IFN-gamma and IL-12 were produced in peritoneal exudate cells (PEC) of TLR4-deficient and wild-type mice after infection, but low levels of cytokines were produced in PEC of TLR2- and MyD88-deficient mice. On the other hand, high levels of IL-4 and IL-10 were produced in PEC of TLR2- and MyD88-deficient mice after infection, but low levels of cytokines were produced in PEC of TLR4-deficient and wild-type mice. The most remarkable histological changes with infiltration of inflammatory cells were observed in lungs of TLR2-deficient mice infected with T. gondii, where severe interstitial pneumonia occurred and abundant T. gondii were found.     

Human pulmonary dirofilariasis: report of six cases

We report six cases of pulmonary dirofilariasis diagnosed at our laboratory with clinical and pathological features. The nodules of dirofilariasis were round in three cases as previously reported, however dumbbell-shaped in two cases. The nodule did not attach to the pleura in four cases. Microscopically, the nodules were granulomas composed of central coagulation necrosis and peripheral fibrosis with round cell infiltration, histiocytes, and multinucleated giant cells. Necrotic pulmonary artery with single or multiple sections of degenerated nematode was observed in the center of the nodule. Dilated bronchioles with inflammation were observed in the nodule in four cases. Collapse of the alveoli, organizing pneumonia, hemosiderin-laden macrophages were observed around the nodule. We suppose that the nodule is not an infarction but a granuloma caused by antigen released from the nematode. Because the pulmonary dirofilariasis is difficult to be differentiated from primary or metastatic lung carcinoma, and the inflammation exists around the nodule, the nodule should be removed surgically.     

Deterioration of visual function as examined by electroretinograms in Toxoplasma gondii-infected IFN-gamma-knockout mice

PURPOSE: To investigate by ERG the effects of Toxoplasma gondii infection on the visual function of interferon gamma knockout (GKO) mice, as a model of immunocompromised hosts. METHODS: Susceptible wild-type (WT) C57BL/6 and GKO C57BL/6 mice were infected with five cysts of the avirulent T. gondii perorally. ERGs were recorded before and after the infection. The eyes of WT and GKO mice were enucleated and prepared for histologic studies 4 weeks and 12 days after infection, respectively. RESULTS: The a- and b-waves of ERGs did not change significantly up to 1 month after infection in WT mice, but those of GKO mice were significantly reduced 11 days after infection. Histopathology revealed focal retinitis and vasculitis in WT mice 4 weeks after infection. Mild inflammation and sludging of blood in the retina and choroid were found in GKO mice 12 days after infection, just before death. Cysts were found in the inner nuclear layer, with little disturbance of the surrounding retinal architecture in both WT and GKO mice. CONCLUSIONS: ERG clearly showed deterioration of visual function in GKO but not in WT mice after T. gondii infection. ERG is a sensitive and reliable method for observing activity in mice severely affected with experimental toxoplasmic retinochoroiditis.     

Cellular FITC-linked immunospecific assay (cell-FLISA) for detection of monoclonal antibodies against cell-surface antigens

A cellular fluorescein isothiocyanate (FITC)-linked immunospecific assay (Cell-FLISA) has been established using the recently developed fluorophotometer for microplates. In the Cell-FLISA system, monoclonal antibodies specific for the surface antigens of live cells are detected by measuring the fluorescence intensity of an FITC-labeled second antibody: goat anti-mouse immunoglobulin antibody. It takes only 2 min to count 96 samples in microplate wells using the fluorophotometer for microplates. Moreover, by this system, the analysis is finished within 2 hr. Thus, the Cell-FLISA system has advantages in screening a large number of samples, such as hybridoma cell lines secreting monoclonal antibodies against cell-surface antigens.     

Acute exacerbation of Toxoplasma gondii infection after hematopoietic stem cell transplantation: five case reports among 279 recipients

Toxoplasmosis is a rare and possibly underestimated complication following hematopoietic stem cell transplantation (HSCT) associated with a high mortality rate, although the incidence of toxoplasmosis after HSCT in Japan has not been established. We retrospectively studied patients with toxoplasmosis after HSCT, and identified five patients who had been diagnosed with an acute exacerbation of toxoplasmosis among 279 HSCT recipients at our institution between 1998 and 2011, representing an incidence of 1.8 %. Among 87 autologous HSCT recipients, one definite case was diagnosed. The serological test for Toxoplasma gondii before HSCT was positive in 18 of 192 allogeneic HSCT recipients. Of the 18 seropositive patients, three had definite infections, and one had possible infection. All four definite cases were diagnosed at autopsy. In the definite cases, three allogeneic HSCT recipients had disseminated or pulmonary toxoplasmosis and one autologous HSCT recipient had toxoplasmic encephalitis, although toxoplasmosis was not suspected at the premortem examination due to non-specific clinical and radiological manifestations. Thus, acute exacerbation of toxoplasmosis should be suspected in recipients after HSCT. Early diagnosis and treatment for toxoplasmosis would certainly contribute to a decrease in mortality after HSCT.     

Induction of protective immunity by DNA vaccination with Toxoplasma gondii HSP70, HSP30 and SAG1 genes

The vaccination with Toxoplasma gondii heat shock protein 70 (T.g.HSP70) gene (a virulent tachyzoite-specific) induced the most prominent reduction in T. gondii loads in various organs of B6 and BALB/c mice at the acute and chronic phases of toxoplasmosis compared with T.g.HSP30 (a bradyzoite-specific) and SAG1 (a tachyzoite-specific) genes. A single gene gun vaccination with 2 microg of T.g.HSP70 gene induced a significant reduction in the number of T. gondii organisms compared with 50 microg of T.g.HSP70 gene vaccination by intramuscular (i.m.) or intraperitoneal (i.p.) injection. The vaccine effects of T.g.HSP70 gene persisted for more than 3 months.