Transepithelial Migration of Toxoplasma gondii Is Linked to Parasite Motility and Virulence

After oral ingestion, Toxoplasma gondii crosses the intestinal epithelium, disseminates into the deep tissues, and traverses biological barriers such as the placenta and the blood-brain barrier to reach sites where it causes severe pathology. To examine the cellular basis of these processes, migration of T. gondii was studied in vitro using polarized host cell monolayers and extracellular matrix. Transmigration required active parasite motility and the highly virulent type I strains consistently exhibited a superior migratory capacity than the nonvirulent type II and type III strains. Type I strain parasites also demonstrated a greater capacity for transmigration across mouse intestine ex vivo, and directly penetrated into the lamina propria and vascular endothelium. A subpopulation of virulent type I parasites exhibited a long distance migration (LDM) phenotype in vitro, that was not expressed by nonvirulent type II and type III strains. Cloning of parasites expressing the LDM phenotype resulted in substantial increase of migratory capacity in vitro and in vivo. The potential to up-regulate migratory capacity in T. gondii likely plays an important role in establishing new infections and in dissemination upon reactivation of chronic infections.

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The Toxoplasma gondii-Shuttling Function of Dendritic Cells Is Linked to the Parasite Genotype

Infection and Immunity ◽

10.1128/iai.01289-08 ◽

2009 ◽

Vol 77 (4) ◽

pp. 1679-1688 ◽

Cited By ~ 75

Author(s):

Henrik Lambert ◽

Polya P. Vutova ◽

William C. Adams ◽

Karin Loré ◽

Antonio Barragan

Keyword(s):

Dendritic Cells ◽

Toxoplasma Gondii ◽

Phenotypic Traits ◽

Type I ◽

Type Ii ◽

Parasite Genotype ◽

Type Iii ◽

Parasite Motility

ABSTRACT Following intestinal invasion, the processes leading to systemic dissemination of the obligate intracellular protozoan Toxoplasma gondii remain poorly understood. Recently, tachyzoites representative of type I, II and III T. gondii populations were shown to differ with respect to their ability to transmigrate across cellular barriers. In this process of active parasite motility, type I strains exhibit a migratory capacity superior to those of the type II and type III strains. Data also suggest that tachyzoites rely on migrating dendritic cells (DC) as shuttling leukocytes to disseminate in tissue, e.g., the brain, where cysts develop. In this study, T. gondii tachyzoites sampled from the three populations were allowed to infect primary human blood DC, murine intestinal DC, or in vitro-derived DC and were compared for different phenotypic traits. All three archetypical lineages of T. gondii induced a hypermigratory phenotype in DC shortly after infection in vitro. Type II (and III) strains induced higher migratory frequency and intensity in DC than type I strains did. Additionally, adoptive transfer of infected DC favored the dissemination of type II and type III parasites over that of type I parasites in syngeneic mice. Type II parasites exhibited stronger intracellular association with both CD11c+ DC and other leukocytes in vivo than did type I parasites. Altogether, these findings suggest that infected DC contribute to parasite propagation in a strain type-specific manner and that the parasite genotype (type II) most frequently associated with toxoplasmosis in humans efficiently exploits DC migration for parasite dissemination.

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Dynamics of Gene Expression in Mice Infected with Different Genotypes of Toxoplasma gondii

10.21203/rs.2.18699/v1 ◽

2019 ◽

Author(s):

Li Yu ◽

Keats Shwab ◽

Rachel D Hill ◽

Xing-Quan zhu ◽

Julia S Gouffon ◽

...

Keyword(s):

Gene Expression ◽

Immune Response ◽

Toxoplasma Gondii ◽

Early Phase ◽

Late Phase ◽

Type I ◽

Type Ii ◽

Type Iii ◽

Peak Expression ◽

Virulent Type

Abstract Background: Toxoplasma gondii is genetically diverse and different genotypes differ markedly in phenotype. The present study aims to define transcriptional patterns and biological processes that characterize host response to distinct strains of T. gondii. Methods: We conducted a time course study of gene expression microarray in mice during acute infection (days 1 to 7) with the highly virulent type I (GT1 strain), intermediately virulent type II (PTG strain) and non-virulent type III (CTG strain) parasites. Results: Overall, the number of genes affected increased from day 1 to day 5, and decreased on day 7. However, type III and type II infections up-regulated more genes than did type I at the very early phase, whereas type I infection up-regulated more genes at the late phase. Gene ontology (GO) analysis showed that the genes related to inflammatory and immune response were mostly affected and the majority were up-regulated, with type III infection inducing a higher degree of change and affecting more genes than did type I at the early phase. However, this pattern was reversed at the late phase. The change of expression during type II infection was between that of types I and III. Many genes associated with inflammatory and immune responses showed bimodal effects, with the first peak expression mostly at day 3 and then a second peak expression mostly at day 5. Several differentially expressed genes, including INF-γ, iNOS, CXCL10/IP-10, and numerous immunity-related GTPases (IRGs) and guanylate-binding proteins (GBPs) were previously experimentally confirmed important host factors in controlling T. gondii infection. Bioinformatic analysis of biological pathways enriched during infection revealed upregulation of pathways relating to cell-mediated immunity and the inflammatory response during all three infection types, though such enrichment was most expansive and pronounced during type I infection, and much less pronounced during type III infection. Conclusions: The findings in our study revealed dynamic differences of gene expression and different pathways of immune response in mice infected with three distinct strains of T. gondii.

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Three Types of Hereditary Antiterombin III Deficiency

10.1055/s-0039-1684714 ◽

1979 ◽

Author(s):

I. Nagy ◽

H. Losonczy

Keyword(s):

Antithrombin Iii ◽

Clinical Signs ◽

Type I ◽

Type Ii ◽

Type Iii ◽

Basic Activity ◽

At Iii ◽

And Function

The authors detected in the last seven years 15 patients with hereditary antithrombin III/AT III/ abnormality. All of them had typical clinical signs of recurrent arterious and venous thromboembolie. The abnormality inherited as an autosomal trait. Three types of the abnormality could be observed. In Type I both quantity and function of AT III were extremely decreased. In type II AT III is normal in quantity but abnormal in function. In Type III AT III is quantitatively normal and also its function seems normal as far as its basic activity is concerned /activity measured in absence of heparin/, but its abnormality becomes manifest in the presence of heparin in vitro/and also in vivo/. 5 of the patients belonged to Type I, 4 to Type II and 6 to Type III. In 60 examined family members of the 15 patients an abnormal AT III could be observed in 44, clinical signs in 23.The examination of AT III activity in the presence of a given amount of heparin ia of great importance in recognition of the different types of antithrombin III abnormalities.

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THE TRANSFORMATION OF PNEUMOCOCCAL TYPES

Journal of Experimental Medicine ◽

10.1084/jem.51.1.123 ◽

1930 ◽

Vol 51 (1) ◽

pp. 123-147 ◽

Cited By ~ 12

Author(s):

Martin H. Dawson

Keyword(s):

Single Cell ◽

Subcutaneous Injection ◽

Intermediate Stage ◽

Group Iv ◽

Type I ◽

Type Ii ◽

Type Iii

1. Type-specific S pneumococci may be transformed from one specific S type into other specific S types through the intermediate stage of the R form. 2. R forms of pneumococi, derived from any specific S type, may be transformed into S organisms of other specific types by the following procedure:—The subcutaneous injection, in white mice, of small amounts of living R forms together with vaccines of heterologous S cultures. (i) S vaccines heated for 15' at temperatures between 60° and 80°C., are effective in causing R forms, derived from heterologous S types, to revert to the type of the vaccine. (ii) S vaccines heated for 15' at temperatures between 80° and 100°C., are not effective in causing R forms, derived from heterologous S types, to revert to the type of the vaccine. (iii) S vaccines heated for 15' at temperatures between 80° and 100°C., may cause 2 R and 3 R cultures to revert to their original S type. (iv) S vaccines of any type, including Type I, heated for 15' at temperatures between 80° and 100°C., are not effective in causing 1 R cultures to revert to their original S type. (v) S vaccines heated for periods as long as two hours at 60°C. are effective in causing R forms, derived from heterologous types, to revert to the type of the vaccine. 3. A single cell R strain, derived from a Type II S pneumococcus, has been successively transformed into a Type III S, a Type I S and a Group IV S culture. 4. Corresponding with the various degrees of "degradation" of the R form there are varying degrees of "development" of the S form. 5. The nature of the conditions responsible for alteration of type as induced by these procedures has been investigated and the causes responsible for the transformations are discussed. 6. All attempts to produce transformation of type in vitro have been unsuccessful. 7. The rô1e which the phenomenon of transformation of type may play in problems of infection and epidemiology is indicated.

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Erythroid progenitors in adult chronic pure red cell aplasia: relationship of in vitro erythroid colonies to therapeutic response

Blood ◽

10.1182/blood.v64.1.71.bloodjournal64171 ◽

1984 ◽

Vol 64 (1) ◽

pp. 71-77 ◽

Cited By ~ 1

Author(s):

C Lacombe ◽

N Casadevall ◽

O Muller ◽

B Varet

Keyword(s):

Myeloproliferative Disorders ◽

Pure Red Cell Aplasia ◽

Type I ◽

Red Cell ◽

Type Ii ◽

Erythroid Progenitors ◽

Chronic Myeloproliferative Disorders ◽

Type Iii ◽

Red Cell Aplasia

Twenty-two cases of idiopathic chronic pure red cell aplasia (PRCA) in adults have been studied to evaluate their erythroid progenitors in vitro using the plasma clot technique. Three types of culture growth patterns were observed and classified as follows. Type I: showing a normal number of autologous CFU-E; type II: CFU-E and BFU-E were detectable but constantly decreased; type III: CFU-E and BFU-E were undetectable. The results were reproducible when patients were studied on two or more occasions. A strong correlation was found between the in vitro growth of autologous erythroid colonies and the results of immunomodulating therapy in 18 evaluable patients. A constant response to immunomodulating treatment was observed in type I patients. A constant failure of treatment was observed in type III patients, whereas results of therapy were unpredictable in type II patients. Two patients with chronic PRCA associated with thymoma and three with chronic myeloproliferative disorders were also studied. Patients with PRCA and thymoma behaved in vitro like type I patients. Patients with chronic myeloproliferative disorders exhibited very low numbers or no CFU-E or BFU-E (type II or III). These data support the hypothesis that at least two mechanisms are responsible for PRCA--one immunologically mediated and the other resulting from a stem cell defect. Moreover, they suggest that the study of erythroid progenitors in vitro might be useful in predicting the immunosuppressive therapy effect in adult chronic PRCA.

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Distinct localization and function of1,4,5IP3 receptor subtypes and the1,3,4,5IP4 receptor GAP1IP4BP in highly purified human platelet membranes

Blood ◽

10.1182/blood.v95.11.3412.011k03_3412_3422 ◽

2000 ◽

Vol 95 (11) ◽

pp. 3412-3422 ◽

Cited By ~ 1

Author(s):

Samer S. El-Daher ◽

Yatin Patel ◽

Ashia Siddiqua ◽

Sheila Hassock ◽

Scott Edmunds ◽

...

Keyword(s):

Inositol Phosphate ◽

Adenosine Monophosphate ◽

Human Platelets ◽

Surface Proteins ◽

Receptor Subtypes ◽

Type I ◽

Type Ii ◽

Type Iii ◽

Receptor Antibodies

Platelet activation is associated with an increase of cytosolic Ca++ levels. The 1,4,5IP3receptors [1,4,5IP3R] are known to mediate Ca++ release from intracellular stores of many cell types. Currently there are at least 3 distinct subtypes of1,4,5IP3R—type I, type II, and type III—with suggestions of distinct roles in Ca++ elevation. Specific receptors for 1,3,4,5IP4 belonging to the GAP1 family have also been described though their involvement with Ca++ regulation is controversial. In this study we report that platelets contain all 3 subtypes of1,4,5IP3R but in different amounts. Type I and type II receptors are predominant. In studies using highly purified platelet plasma (PM) and intracellular membranes (IM) we report a distinct localization of these receptors. The PM fractions were found to contain the type III 1,4,5IP3R and GAP1IP4BP in contrast to IM, which contained type I1,4,5IP3R. The type II receptor exhibited a dual distribution. In studies examining the labeling of surface proteins with biotin in intact platelets only the type III1,4,5IP3R was significantly labeled. Immunogold studies of ultracryosections of human platelets showed significantly more labeling of the PM with the type III receptor antibodies than with type I receptor antibodies. Ca++ flux studies were carried out with the PM to demonstrate in vitro function of inositol phosphate receptors. Ca++ release activities were present with both 1,4,5IP3 and1,3,4,5IP4 (EC50 = 1.3 and 0.8 μmol/L, respectively). Discrimination of the Ca++-releasing activities was demonstrated with cyclic adenosine monophosphate (cAMP)-dependent protein kinase (cAMP-PK) specifically inhibiting 1,4,5IP3 but not1,3,4,5IP4-induced Ca++ flux. In experiments with both PM and intact platelets, the1,4,5IP3Rs but not GAP1IP4BP were found to be substrates of cAMP-PK and cGMP-PK. Thus the Ca++ flux property of1,3,4,5IP4 is insensitive to cAMP-PK. These studies suggest distinct roles for the1,4,5IP3R subtypes in Ca++movements, with the type III receptor and GAP1IP4BPassociated with cation entry in human platelets and the type I receptor involved with Ca++ release from intracellular stores.

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Distinct localization and function of1,4,5IP3 receptor subtypes and the1,3,4,5IP4 receptor GAP1IP4BP in highly purified human platelet membranes

Blood ◽

10.1182/blood.v95.11.3412 ◽

2000 ◽

Vol 95 (11) ◽

pp. 3412-3422 ◽

Cited By ~ 43

Author(s):

Samer S. El-Daher ◽

Yatin Patel ◽

Ashia Siddiqua ◽

Sheila Hassock ◽

Scott Edmunds ◽

...

Keyword(s):

Inositol Phosphate ◽

Adenosine Monophosphate ◽

Human Platelets ◽

Surface Proteins ◽

Receptor Subtypes ◽

Type I ◽

Type Ii ◽

Type Iii ◽

Receptor Antibodies

Abstract Platelet activation is associated with an increase of cytosolic Ca++ levels. The 1,4,5IP3receptors [1,4,5IP3R] are known to mediate Ca++ release from intracellular stores of many cell types. Currently there are at least 3 distinct subtypes of1,4,5IP3R—type I, type II, and type III—with suggestions of distinct roles in Ca++ elevation. Specific receptors for 1,3,4,5IP4 belonging to the GAP1 family have also been described though their involvement with Ca++ regulation is controversial. In this study we report that platelets contain all 3 subtypes of1,4,5IP3R but in different amounts. Type I and type II receptors are predominant. In studies using highly purified platelet plasma (PM) and intracellular membranes (IM) we report a distinct localization of these receptors. The PM fractions were found to contain the type III 1,4,5IP3R and GAP1IP4BP in contrast to IM, which contained type I1,4,5IP3R. The type II receptor exhibited a dual distribution. In studies examining the labeling of surface proteins with biotin in intact platelets only the type III1,4,5IP3R was significantly labeled. Immunogold studies of ultracryosections of human platelets showed significantly more labeling of the PM with the type III receptor antibodies than with type I receptor antibodies. Ca++ flux studies were carried out with the PM to demonstrate in vitro function of inositol phosphate receptors. Ca++ release activities were present with both 1,4,5IP3 and1,3,4,5IP4 (EC50 = 1.3 and 0.8 μmol/L, respectively). Discrimination of the Ca++-releasing activities was demonstrated with cyclic adenosine monophosphate (cAMP)-dependent protein kinase (cAMP-PK) specifically inhibiting 1,4,5IP3 but not1,3,4,5IP4-induced Ca++ flux. In experiments with both PM and intact platelets, the1,4,5IP3Rs but not GAP1IP4BP were found to be substrates of cAMP-PK and cGMP-PK. Thus the Ca++ flux property of1,3,4,5IP4 is insensitive to cAMP-PK. These studies suggest distinct roles for the1,4,5IP3R subtypes in Ca++movements, with the type III receptor and GAP1IP4BPassociated with cation entry in human platelets and the type I receptor involved with Ca++ release from intracellular stores.

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Type II Keratins Are Phosphorylated on a Unique Motif during Stress and Mitosis in Tissues and Cultured Cells

Molecular Biology of the Cell ◽

10.1091/mbc.01-12-0591 ◽

2002 ◽

Vol 13 (6) ◽

pp. 1857-1870 ◽

Cited By ~ 57

Author(s):

Diana M. Toivola ◽

Qin Zhou ◽

Luc S. English ◽

M. Bishr Omary

Keyword(s):

Cultured Cells ◽

Uv Light ◽

Ex Vivo ◽

Psoriatic Skin ◽

Type I ◽

Type Ii ◽

Intermediate Filament Proteins ◽

Phosphatase Inhibitors

Epithelial cell keratins make up the type I (K9–K20) and type II (K1–K8) intermediate filament proteins. In glandular epithelia, K8 becomes phosphorylated on S73 (71LLpSPL) in human cultured cells and tissues during stress, apoptosis, and mitosis. Of all known proteins, the context of the K8 S73 motif (LLS/TPL) is unique to type II keratins and is conserved in epidermal K5/K6, esophageal K4, and type II hair keratins, except that serine is replaced by threonine. Because knowledge regarding epidermal and esophageal keratin regulation is limited, we tested whether K4–K6 are phosphorylated on the LLTPL motif. K5 and K6 become phosphorylated in vitro on threonine by the stress-activated kinase p38. Site-specific anti-phosphokeratin antibodies to LLpTPL were generated, which demonstrated negligible basal K4–K6 phosphorylation. In contrast, treatment of primary keratinocytes and other cultured cells, and ex vivo skin and esophagus cultures, with serine/threonine phosphatase inhibitors causes a dramatic increase in K4–K6 LLpTPL phosphorylation. This phosphorylation is accompanied by keratin solubilization, filament reorganization, and collapse. K5/K6 LLTPL phosphorylation occurs in vivo during mitosis and apoptosis induced by UV light or anisomycin, and in human psoriatic skin and squamous cell carcinoma. In conclusion, type II keratins of proliferating epithelia undergo phosphorylation at a unique and conserved motif as part of physiological mitotic and stress-related signals.

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Type II Toxoplasma gondii Induction of CD40 on Infected Macrophages Enhances Interleukin-12 Responses

Infection and Immunity ◽

10.1128/iai.01615-14 ◽

2014 ◽

Vol 82 (10) ◽

pp. 4047-4055 ◽

Cited By ~ 19

Author(s):

Pedro Morgado ◽

Dattanand M. Sudarshana ◽

Lanny Gov ◽

Katherine S. Harker ◽

Tonika Lam ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Transcript Level ◽

Forward Genetics ◽

Interleukin 12 ◽

Type I ◽

Dependent Manner ◽

Type Ii ◽

Content Type ◽

Type Iii ◽

Infected Cells

ABSTRACTToxoplasma gondiiis an obligate intracellular parasite that can cause severe neurological disease in infected humans. CD40 is a receptor on macrophages that plays a critical role in controllingT. gondiiinfection. We examined the regulation of CD40 on the surface ofT. gondii-infected bone marrow-derived macrophages (BMdMs).T. gondiiinduced CD40 expression both at the transcript level and on the cell surface, and interestingly, the effect was parasite strain specific: CD40 levels were dramatically increased in type IIT. gondii-infected BMdMs compared to type I- or type III-infected cells. Type II induction of CD40 was specific to cells harboring intracellular parasites and detectable as early as 6 h postinfection (hpi) at the transcript level. CD40 protein expression peaked at 18 hpi. Using forward genetics with progeny from a type II × type III cross, we found that CD40 induction mapped to a region of chromosome X that included the gene encoding the dense granule protein 15 (GRA15). Using type I parasites stably expressing the type II allele ofGRA15(GRA15II), we found that type I GRA15IIparasites induced the expression of CD40 on infected cells in an NF-κB-dependent manner. In addition, stable expression of hemagglutinin-tagged GRA15IIin THP-1 cells resulted in CD40 upregulation in the absence of infection. Since CD40 signaling contributes to interleukin-12 (IL-12) production, we examined IL-12 from infected macrophages and found that CD40L engagement of CD40 amplified the IL-12 response in type II-infected cells. These data indicate that GRA15IIinduction of CD40 promotes parasite immunity through the production of IL-12.

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Erythroid progenitors in adult chronic pure red cell aplasia: relationship of in vitro erythroid colonies to therapeutic response

Blood ◽

10.1182/blood.v64.1.71.71 ◽

1984 ◽

Vol 64 (1) ◽

pp. 71-77 ◽

Cited By ~ 33

Author(s):

C Lacombe ◽

N Casadevall ◽

O Muller ◽

B Varet

Keyword(s):

Myeloproliferative Disorders ◽

Pure Red Cell Aplasia ◽

Type I ◽

Red Cell ◽

Type Ii ◽

Erythroid Progenitors ◽

Chronic Myeloproliferative Disorders ◽

Type Iii ◽

Red Cell Aplasia

Abstract Twenty-two cases of idiopathic chronic pure red cell aplasia (PRCA) in adults have been studied to evaluate their erythroid progenitors in vitro using the plasma clot technique. Three types of culture growth patterns were observed and classified as follows. Type I: showing a normal number of autologous CFU-E; type II: CFU-E and BFU-E were detectable but constantly decreased; type III: CFU-E and BFU-E were undetectable. The results were reproducible when patients were studied on two or more occasions. A strong correlation was found between the in vitro growth of autologous erythroid colonies and the results of immunomodulating therapy in 18 evaluable patients. A constant response to immunomodulating treatment was observed in type I patients. A constant failure of treatment was observed in type III patients, whereas results of therapy were unpredictable in type II patients. Two patients with chronic PRCA associated with thymoma and three with chronic myeloproliferative disorders were also studied. Patients with PRCA and thymoma behaved in vitro like type I patients. Patients with chronic myeloproliferative disorders exhibited very low numbers or no CFU-E or BFU-E (type II or III). These data support the hypothesis that at least two mechanisms are responsible for PRCA--one immunologically mediated and the other resulting from a stem cell defect. Moreover, they suggest that the study of erythroid progenitors in vitro might be useful in predicting the immunosuppressive therapy effect in adult chronic PRCA.

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