Bovine mononuclear cell lines transformed by <i>Theileria parva</i> or <i>Theileria annulata</i> express different subpopulation markers

Spooner, R. L.; Innes, Elisabeth A.; Glass, Elizabeth J.; Millar, P.G.; Brown, C.G.D.

doi:10.1111/j.1365-3024.1988.tb00249.x

Cited by 34 publications

(27 citation statements)

References 15 publications

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“…However, there are some dierences between the two species. T. parva preferentially infects T-cells, whereas T. annulata mainly transforms MHC class II-positive cells (Spooner et al 1988). Recently it has been con®rmed that macrophages (Campbell et al 1994;Sager et al 1997) and B-lymphocytes are targets of T. annulata (Sager et al 1998) son et al 1996), indicating that the pathogenesis of the disease is associated with infection of T-cells.…”

Section: Pathogenesis Of Theileriosismentioning

confidence: 99%

Review: the cellular basis of the immunity to and immunopathogenesis of tropical theileriosis

Ahmed

Mehlhorn

1999

Parasitol Res

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The intracellular protozoan parasite Theileria annulata causes a severe and often fatal disease of pure and crossbred cattle in tropical and subtropical countries. Animals that recover from the infection are immune against challenge with homologous parasite strains. In the present review we refer to the role of immunocompetent cells and their products in containing the infection or in facilitating the progress of the disease. Parasite-infected host cells produce cytokines, which, depending on their concentration and timing of production, may enhance the establishment of the infection. Thus, cell lines producing high levels of proinflammatory cytokines cause severe postvaccinal reactions when inoculated into cattle. This may be supported by an aberrant non-specific activation of naive T-cells, leading to the production of high levels of gamma-interferon (IFN-y). Under these circumstances development of the specific immune response may be inhibited. At this stage, innate immune reactions are operating to contain the infection. Natural killer cells and macrophages may represent the most important part of this immunity. Antibodies and specific T-lymphocytes, CD4+ T-cells and cytotoxic T-lymphocytes (CTLs), play the most important role in a challenge infection. In this context, CD4+ T-cells produce cytokines required for the clonal expansion of CTLs that kill their target cells in a major histocompatibility complex (MHC) class I-restricted manner. In addition, CD4+ T-cells produce macrophage-activating cytokines such as IFN-gamma. Such activated macrophages produce mediators such as NO, which destroy the intracellular schizonts. Attempts have been directed toward the identification of parasite antigens involved in the induction of immunity. To date, only a limited number of sporozoite and merozoite antigens have been identified and examined for their immunogenicity, and the protection achieved is partial. An effective vaccine must include schizont proteins, notably, those proteins that are secreted into the host cell cytoplasm because these may have access to the MHC class I and II compartments to be presented to CTLs and CD4+ T-cells, respectively. Several schizont proteins have been identified and these are now under investigation.

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Section: Pathogenesis Of Theileriosismentioning

confidence: 99%

Review: the cellular basis of the immunity to and immunopathogenesis of tropical theileriosis

Ahmed

Mehlhorn

1999

Parasitol Res

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“…Cytauxzoon was originally established as a distinct genus from Theileria due to its invasion of monocytes rather than lymphocytes [14]. However, species in both genera were later shown to infect both lymphocytes and monocytes [26–28], and consequently the majority of Cytauxzoon species were reclassified as Theileria [26,29–34]. Despite the suggestion to completely eliminate the genus Cytauxzoon [33], Cytauxzoon felis was never reclassified as Theileria , and for decades was the lone species recognized within the genus.…”

Section: Introductionmentioning

confidence: 99%

Mitochondrial Genome Sequences and Structures Aid in the Resolution of Piroplasmida phylogeny

et al. 2016

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The taxonomy of the order Piroplasmida, which includes a number of clinically and economically relevant organisms, is a hotly debated topic amongst parasitologists. Three genera (Babesia, Theileria, and Cytauxzoon) are recognized based on parasite life cycle characteristics, but molecular phylogenetic analyses of 18S sequences have suggested the presence of five or more distinct Piroplasmida lineages. Despite these important advancements, a few studies have been unable to define the taxonomic relationships of some organisms (e.g. C. felis and T. equi) with respect to other Piroplasmida. Additional evidence from mitochondrial genome sequences and synteny should aid in the inference of Piroplasmida phylogeny and resolution of taxonomic uncertainties. In this study, we have amplified, sequenced, and annotated seven previously uncharacterized mitochondrial genomes (Babesia canis, Babesia vogeli, Babesia rossi, Babesia sp. Coco, Babesia conradae, Babesia microti-like sp., and Cytauxzoon felis) and identified additional ribosomal fragments in ten previously characterized mitochondrial genomes. Phylogenetic analysis of concatenated mitochondrial and 18S sequences as well as cox1 amino acid sequence identified five distinct Piroplasmida groups, each of which possesses a unique mitochondrial genome structure. Specifically, our results confirm the existence of four previously identified clades (B. microti group, Babesia sensu stricto, Theileria equi, and a Babesia sensu latu group that includes B. conradae) while supporting the integration of Theileria and Cytauxzoon species into a single fifth taxon. Although known biological characteristics of Piroplasmida corroborate the proposed phylogeny, more investigation into parasite life cycles is warranted to further understand the evolution of the Piroplasmida. Our results provide an evolutionary framework for comparative biology of these important animal and human pathogens and help focus renewed efforts toward understanding the phylogenetic relationships within the group.

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Section: Introductionmentioning

confidence: 99%

“…Special mechanisms warrant that upon cell division, each daughter cell contains the parasite (Hulliger 1965). Experiments with isolated bovine peripheral blood mononuclear cells (PBM) showed that T. parva preferentially infects T cells (Spooner et al 1988. These maintain the expression of T cell markers such as CD4 and/or CD8 (Baldwin et al 1988, Spooner et al 1988 and express in addition activation markers such as MHC class II molecules.…”

Section: Introductionmentioning

confidence: 99%

Interferon production by Theileria annulata‐transformed cell lines is restricted to the beta family

Sager

Brunschwiler

Jungi

1998

Parasite Immunology

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Theileria are tick-transmitted protozoans causing often fatal diseases in ruminants. Theileria sporozoites immortalize and transform host cells of haematopoietic origin. Transformation is associated with profound functional alterations. For example, bovine cells infected by Theileria annulata or T. parva. constitutively produce interferon (IFN). In this study, the type and family of IFN produced by a panel of T. annulata-transformed cell lines and a T. parva-transformed cell line was investigated, using molecular probes specific for the members of the IFN-alpha, IFN-beta, IFN-gamma and IFN-omega family. T. parva-transformed cells produced IFN-gamma exclusively, whereas T. annulata-infected cells expressed type I IFN only. Analysis of mRNA expression showed that this type I IFN was confined to IFN-beta, regardless of the cellular origin of the transformed cells. When cells were exposed to double-stranded RNA (poly (I:C)) which induces IFN production in other systems, a 10-5,000 fold increase in IFN activity was noted. The amounts of IFN-beta mRNA were increased, but mRNA coding for IFN-alpha, IFN-omega or IFN-gamma was not detected. In contrast, primary macrophages, from which many of the tested lines were derived, expressed IFN-alpha, IFN-beta and IFN-omega mRNA to similar degrees when stimulated by LPS or poly (I:C). Thus, T. annulata appears to constitutively turn on IFN-beta gene transcription while silencing the genes coding for IFN-alpha and IFN-omega.

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Bovine mononuclear cell lines transformed by Theileria parva or Theileria annulata express different subpopulation markers

Cited by 34 publications

References 15 publications

Review: the cellular basis of the immunity to and immunopathogenesis of tropical theileriosis

Review: the cellular basis of the immunity to and immunopathogenesis of tropical theileriosis

Mitochondrial Genome Sequences and Structures Aid in the Resolution of Piroplasmida phylogeny

Interferon production by Theileria annulata‐transformed cell lines is restricted to the beta family

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