Mouse models of chronic toxoplasmosis and atopic dermatitis (AD) were combined to clarify the effect of opportunistic Toxoplasma gondii infection on the development of AD. AD was induced as a chronic contact hypersensitivity (CHS) with repeated challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) on the dorsal skin of mice. TNCB induced skin thickness increases in both normal and toxoplasmic mice. The changing patterns were different from the sigmoidal which saturated at 20 days in normal mice to the convex saturated at 12 days in toxoplasmic mice with the crossing at 18 days. Compared to normal mice, toxoplasmic mice presented CHS more severely in earlier times and then moderately in later times. These data suggest that host immune modification by T. gondii infection enhances CHS in early times of atopic stimulation but soothes the reaction of CHS in later times in mouse model.
Animals ; Dermatitis, Contact/*immunology/parasitology ; Disease Models, Animal ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Picryl Chloride/adverse effects ; Skin/immunology/parasitology ; Toxoplasmosis/*immunology/parasitology

This study investigated whether elevated host immune capacity can inhibit T. gondii infection. For this purpose, we used silk protein extracted from Bombyx mori cocoons as a natural supplement to augment immune capacity. After silk protein administration to BALB/c mice for 6 weeks, ratios of T lymphocytes (CD4+ and CD8+ T-cells) and splenocyte proliferative capacities in response to Con A or T. gondii lysate antigen (TLA) were increased. Of various cytokines, which regulate immune systems, Th1 cytokines, such as IFN-gamma, IL-2, and IL-12, were obviously increased in splenocyte primary cell cultures. Furthermore, the survival of T. gondii (RH strain)-infected mice increased from 2 days to 5 or more days. In a state of immunosuppression induced by methylprednisolone acetate, silk protein-administered mice were resistant to reduction in T-lymphocyte (CD4+ and CD8+ T-cells) numbers and the splenocyte proliferative capacity induced by Con A or TLA with a statistical significance. Taken together, our results suggest that silk protein augments immune capacity in mice and the increased cellular immunity by silk protein administration increases host protection against acute T. gondii infection.
Animals ; Bombyx/*chemistry ; CD4-CD8 Ratio ; Cell Proliferation ; Cells, Cultured ; Cytokines/secretion ; Insect Proteins/*immunology ; Leukocytes, Mononuclear/immunology ; Male ; Mice ; Mice, Inbred BALB C ; Silk/immunology ; Spleen/immunology ; Survival Analysis ; Toxoplasma/*immunology/pathogenicity ; Toxoplasmosis, Animal/immunology/*prevention & control

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-1alpha, IL-1beta, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of CD8alpha+/CD11c+ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis.
Animals ; Antigens, CD11c/analysis ; Antigens, CD8/analysis ; Cytokines/*blood/*secretion ; Dendritic Cells/chemistry/*immunology ; Disease Models, Animal ; Flow Cytometry ; Mice ; Mice, Inbred BALB C ; Rodent Diseases/immunology ; Spleen/*immunology ; Time Factors ; Toxoplasmosis, Animal/*immunology

OBJECTIVETo explore the behavioral risk of toxoplasma infection in special population.

METHODSSerum samples from workers in slaughterhouse were collected and tested for the detection of cAg, toxo-IgG, toxo-IgM antibody to toxoplasma, using ELISA. Behavioral measurements were conducted through questionnaire, which was developed according to theory of reasoned action which consists of a measurement model that specifies the relation of measured to behavioral variables and a behavioral variable model to show the influence of behavior variables on each other. Factor analysis methods were used for estimating the parameter of the former and path analyses method for the latter.

RESULTSWith data from 302 research subjects, the responding rate was 95.87%. The overall infection rate was of 19.20% including 15.89% having cAg, 5.63% with toxo-IgG, 2.32% with toxo-IgM, 1.32% with the third of cAg, toxo-IgG and toxo-IgM, 2.65% with the both cAg and toxo-IgG, 1.99% with the both cAg and IgM respectively. There was significant association between toxoplasma infections and contact with dystocia or live pigs, body fluid or harslet. There was no relation between toxoplasma infections and abortion.

RESULTSfrom miscarriage factor analyses showed that except evaluation of behavioral outcomes and behavioral attitudes, internal consistence reliability of others behavioral variables was good (Cronbach's alpha > 0.7). These behavior variables could be explained by their measure items. Path analyses suggested that two components had provided significant independent contributions to those preventive behaviors which significantly correlated to toxoplama infections. Half of the contribution leading to toxoplasma infections had come from behavioral factors. Belief was relatively more important in predicting the preventive behavior than subjective norm.

CONCLUSIONOur findings supported the application of reasoned action theory in understanding the role of behavioral factors in toxoplasma infection.

Abattoirs ; Animals ; Antibodies, Protozoan ; blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Models, Biological ; Occupational Diseases ; blood ; etiology ; parasitology ; Occupational Exposure ; adverse effects ; statistics & numerical data ; Risk Factors ; Toxoplasma ; immunology ; Toxoplasmosis ; parasitology ; transmission ; Toxoplasmosis, Animal ; parasitology ; transmission

In recent years, worldwide surveys of Toxoplasma gondii infection in dogs have been reported. However, only limited surveys of T. gondii infection in police dogs have been available, including China. In the present study, we report the seroprevalence of T. gondii in police dogs in Shenyang, northeastern China. Sera from 291 police dogs were examined for T. gondii antibodies with the modified agglutination test (MAT), and 30.9% animals were tested seropositive. The results of the present study indicated a relatively high prevalence of T. gondii infection in police dogs in Shenyang, China.
Agglutination Tests/veterinary ; Animals ; Antibodies, Protozoan/*blood ; China/epidemiology ; Dog Diseases/*epidemiology/parasitology ; Dogs ; Female ; Male ; Seroepidemiologic Studies ; Toxoplasma/*immunology/isolation & purification ; Toxoplasmosis, Animal/*epidemiology/parasitology

A total of 542 children under 10 years of age, admitted to the Seoul National University Children's Hospital, was examined for antibody titers of Toxoplasma gondii using indirect latex agglutination (ILA) test. Among them, 7.7% showed positive titers higher than 1:32, without significant difference between males (7.3%) and females (8.5%). The seropositive rate increased with age although the statistical significance was negligible (0.05 < P < 0.1). By residential areas, the prevalence appeared higher among children from southern provinces (Kyongsang-do and Cholla do) than those from other areas, but the statistical significance was also very low (0.05 < P < 0.1). When the seropositive cases were analyzed by coincidental diseases, the prevalence was significantly higher in patients with congenital diseases than in patients with non-congenital diseases (P < 0.05). The results showed that the seropositive rate of toxoplasmosis in children examined was not high compared with other endemic countries. Some correlations are suggested between toxoplasmosis and congenital anomalies in Korea.
Animal ; Antibodies, Protozoan/blood* ; Child ; Child, Preschool ; Female ; Human ; Infant ; Korea/epidemiology ; Latex Fixation Tests ; Male ; Prevalence ; Seroepidemiologic Studies ; Toxoplasma/immunology* ; Toxoplasmosis/epidemiology*

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis with worldwide distribution. The present study investigated the prevalence of T. gondii in dogs in Zhanjiang city, southern China, using both serological and molecular detection. A total of 364 serum samples and 432 liver tissue samples were collected from the slaughter house between December 2012 and January 2013 and were examined for T. gondii IgG antibody by ELISA and T. gondii DNA by semi-nested PCR based on B1 gene, respectively. The overall seroprevalence of T. gondii IgG antibody was 51.9%, and T. gondii DNA was detected in 37 of 432 (8.6%) liver tissue samples. These positive DNA samples were analyzed by PCR-RFLP at 3'- and 5'-SAG2. Only 8 samples gave the PCR-RFLP data, and they were all classified as type I, which may suggest that the T. gondii isolates from dogs in Zhanjiang city may represent type I or type I variant. This study revealed the high prevalence of T. gondii infection in dogs in Zhanjiang city, southern China. Integrated measures should be taken to prevent and control toxoplasmosis in dogs in this area for public health concern.
Animals ; Antibodies, Protozoan/blood ; China/epidemiology ; Dog Diseases/epidemiology/*parasitology ; Dogs ; Female ; Genotype ; Liver/parasitology ; Male ; Toxoplasma/classification/genetics/immunology/*isolation & purification ; Toxoplasmosis, Animal/blood/epidemiology/*parasitology

OBJECTIVETo characterize the immune response induced by SAG1 encoding plasmid combined with IL-2 gene adjuvant in mice and to assess the protective effect of this vaccination against toxoplasmosis.

METHODSMice were co-injected intramuscularly with plasmid encoding Toxoplasma gondii SAG1 plus murine IL-2 expression vector at a dose of 100 microg. Booster immunizations were employed 2 more times at 3-week interval. As controls, mice were inoculated with PBS or empty plasmid pcDNA3. Humoral and cellular responses were assayed using ELISA for the determination of Ab, Ab isotype and IFN-gamma, as well as IL-4. To detect the integration and dissemination of DNA in the injected mice, PCR and in situ hybridization were performed. All mice were then infected with highly virulent RH tachyzoites of Toxoplasma gondii intraperitoneally.

RESULTSSignificant increases in specific IgG levels were observed in mice after immunization three times with SAG1 expression plasmid. With respect to the IgG isotype, co-inoculation of IL-2 expression plasmid enhanced the level of IgG2a and the production of IFN-gamma. Challenging mice by vaccinating with combined plasmids with RH tachyzoites resulted in prolonged survival.

CONCLUSIONHumoral and cytokine responses elicited by SAG1 DNA immunization can be modulated by co-inoculation with IL-2 expression plasmid. The use of DNA vaccine in combination with an appropriate cytokine gene to prevent T. gondii infection warrants further investigation.

Animals ; Antibodies, Protozoan ; blood ; Antigens, Protozoan ; Cytokines ; biosynthesis ; Female ; Immunization ; Immunoglobulin G ; blood ; classification ; Interleukin-2 ; genetics ; Mice ; Protozoan Proteins ; genetics ; Protozoan Vaccines ; immunology ; Toxoplasma ; immunology ; Toxoplasmosis, Animal ; prevention & control ; Vaccines, DNA ; immunology

The principal objective of this study was to investigate the prevalence of toxoplasmosis in household and stray cats in Seoul, Republic of Korea. We collected blood samples from 72 stray and 80 household cats, and all samples were examined by ELISA and nested PCR. The overall positive rates of Toxoplasma gondii in stray cats were 38.9% (28/72), with 15.3% (11/72) in ELISA and 30.6% (22/72) in PCR. The positive rate in male stray cats was slightly higher than that of female stray cats. The highest positive rate of T. gondii infection was noted in Gangnam and Songpa populations in ELISA and in Gwangjin population in PCR. In household cats, however, we could not detect any specific antibodies or DNA for T. gondii. In conclusion, we recognized that the infection rate of toxoplasmosis in stray cats in Seoul was considerably high but household cats were free from infection.
Animals ; Animals, Domestic/parasitology ; Antibodies, Protozoan/blood ; Cat Diseases/*epidemiology/immunology/parasitology ; Cats ; Female ; Male ; Prevalence ; Republic of Korea/epidemiology ; Toxoplasma/genetics/immunology/*isolation & purification ; Toxoplasmosis, Animal/*epidemiology/immunology/parasitology

Toxoplasma gondii Korean isolate (KI-1) tachyzoites were inoculated intraduodenally to BALB/c mice using a silicon tube, and the course of infection and immune responses of mice were studied. Whereas control mice, that were infected intraperitoneally, died within day 7 post-infection (PI), the intraduodenally infected mice survived until day 9 PI (infection with 1x10(5) tachyzoites) or day 11 PI (with 1x10(6) tachyzoites). Based on histopathologic (Giemsa stain) and PCR (B1 gene) studies, it was suggested that tachyzoites, after entering the small intestine, invaded into endothelial cells, divided there, and propagated to other organs. PCR appeared to be more sensitive than histopathology to detect infected organs and tissues. The organisms spread over multiple organs by day 6 PI. However, proliferative responses of splenocytes and mesenteric lymph node (MLN) cells in response to con A or Toxoplasma lysate antigen decreased significantly, suggesting immunosuppression. Splenic CD4+ and CD8+ T-lymphocytes showed decreases in number until day 9 PI, whereas IFN-gamma and IL-10 decreased slightly at day 6 PI and returned to normal levels by day 9 PI. No TNF-alpha was detected throughout the experimental period. The results showed that intraduodenal infection with KI-1 tachyzoites was successful but did not elicit significant mucosal immunity in mice and allowed dissemination of T. gondii organisms to systemic organs. The immunosuppression of mice included reduced lymphoproliferative responses to splenocytes and MLN cells to mitogen and low production of cytokines, such as IFN-gamma, TNF-alpha, and IL-10, in response to T. gondii infection.
Animals ; Cell Proliferation ; Cytokines/secretion ; Disease Models, Animal ; Duodenum/immunology/parasitology/pathology ; Endothelial Cells/parasitology ; Histocytochemistry ; Immune Tolerance ; Lymph Nodes/immunology ; Mice ; Mice, Inbred BALB C ; Polymerase Chain Reaction ; Rodent Diseases/immunology/parasitology/pathology ; T-Lymphocyte Subsets/immunology ; Toxoplasma/*immunology/pathogenicity ; Toxoplasmosis, Animal/*immunology/parasitology/pathology