Trypanosoma brucei: in vitro slender-to-stumpy differentiation of culture-adapted, monomorphic bloodstream forms

Breidbach, Tanja; Ngazoa, Elise Solange; Steverding, Dietmar

doi:10.1016/s0014-4894(02)00133-9

Cited by 31 publications

(38 citation statements)

References 19 publications

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“…5E, SI Fig. 9), similar to earlier results with the cAMP analog (12,13). However, analog treated parasites did not give rise to fully established procyclic forms, because growth stopped after Ϸ1 week.…”

Section: Brucei By 8-pcpt-2ј-o-me-5ј-amp (Squares) or 8-pcpt-2ј-o-me-supporting

confidence: 89%

“…5B). After 48 h of treatment with 8-pCPT-2Ј-OMe-5Ј-AMP, NADH diaphorase activity, a marker of intermediate or stumpy forms (13,35,36), was detected (observed by the appearance of dark precipitates in the trypanosome body) (Fig. 5C).…”

Section: Brucei By 8-pcpt-2ј-o-me-5ј-amp (Squares) or 8-pcpt-2ј-o-me-mentioning

confidence: 99%

“…While characterizing stumpy-inducing factor (SIF), which can transform slender forms of T. brucei to stumpy forms, these investigators used a cell-permeable cAMP analog (8-pCPTcAMP) to induce slender-to-stumpy transformation in pleomorphic bloodstream-form T. brucei (12). The phenotype caused by this analog was further characterized to confirm the stumpy form (13). As a result, it commonly has been accepted that increased cAMP could cause the slender-to-stumpy transformation.…”

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confidence: 99%

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Hydrolysis products of cAMP analogs cause transformation ofTrypanosoma bruceifrom slender to stumpy-like forms

Laxman¹,

Riechers²,

Sadı́lek

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

110

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African sleeping sickness is a disease caused by Trypanosoma brucei. T. brucei proliferate rapidly in the mammalian bloodstream as long, slender forms, but at higher population densities they transform into nondividing, short, stumpy forms. This is thought to be a mechanism adopted by T. brucei to establish a stable hostparasite relationship and to allow a transition into the insect stage of its life cycle. Earlier studies have suggested a role for cAMP in mediating this transformation. In this study, using membranepermeable nucleotide analogs, we show that it is not the cAMP analogs themselves but rather the hydrolyzed products of membrane-permeable cAMP analogs that prevent proliferation of T. brucei. The metabolic products are more potent than the cAMP analogs, and hydrolysis-resistant cAMP analogs are not antiproliferative. We further show that the antiproliferative effect of these membrane-permeable adenosine analogs is caused by transformation into forms resembling short, stumpy bloodstream forms. These data suggest that the slender-to-stumpy transformation of T. brucei may not be mediated directly by cAMP and also raise the possibility of using such adenosine analogs as antitrypanosomal drugs.adenosine ͉ EPACs ͉ phosphodiesterases ͉ trypanosomes

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Section: Brucei By 8-pcpt-2ј-o-me-5ј-amp (Squares) or 8-pcpt-2ј-o-me-supporting

confidence: 89%

Section: Brucei By 8-pcpt-2ј-o-me-5ј-amp (Squares) or 8-pcpt-2ј-o-me-mentioning

confidence: 99%

mentioning

confidence: 99%

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Hydrolysis products of cAMP analogs cause transformation ofTrypanosoma bruceifrom slender to stumpy-like forms

Laxman¹,

Riechers²,

Sadı́lek

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

110

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“…Unexpected SL-containing L and S RNAs correspond to the ∼4.0-kb and ∼1.4-kb bands seen in the northern blots shown in Fig. 1B [20]. After 48 hr, the medium is changed to PCF medium supplemented with cis-aconitate and citrate, and the BSFgrowth temperature of 37°C is dropped to the PCF-growth temperature of 26°C [21].…”

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confidence: 96%

Different trans RNA splicing events in bloodstream and procyclic Trypanosoma brucei

Helm

Wilson

Donelson

2008

Molecular and Biochemical Parasitology

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A distinctive feature of Trypanosoma brucei and other trypanosomatids is that most of their genes are transcribed into long polycistronic RNAs [1], which are processed into mature monocistronic mRNAs bearing a 39-nucleotide spliced leader (SL) at their 5′ ends that is derived from a capped precursor RNA of ∼140 nucleotides [2;3]. This trans RNA splicing serves two major functions: in conjunction with 3′ polyadenylation it generates the mature mRNAs from polycistronic primary transcripts, and via the SL it provides a 5′ cap structure for each mRNA [1;4]. In contrast to cis RNA splicing of introns in other eukaryotes, trans RNA splicing unites exons from two independently transcribed RNAs. trans and cis RNA splicing, however, share several similarities. For example, at least some components of the cis RNA spliceosomes are conserved in T. brucei, and both cis and trans RNA splicing utilize the same general mechanism and require the same general sequence motifs [4]. During an examination of the effect of different 3′ UTRs on gene expression in T. brucei, we noticed differences between bloodstream form (BSF) and procyclic form (PCF) trypanosomes in the addition of SLs to RNAs transcribed from a luciferase reporter gene inserted into the rRNA gene locus. Further inspection revealed that in PCF cells the expected SL addition occurs to precursor luciferase RNA, whereas in BSF cells multiple SL additions occur to the same luciferase RNA that are independent of the 5′ and 3′ UTR sequences. Fig. 1A depicts the luciferase reporter plasmid, pMP, integrated into the rRNA gene spacer region of the T. brucei genome that was used for the experiments. This plasmid is derived from plasmid pHD496 (kindly provided by C. Clayton), and is used to measure luciferase activity in BSF and PCF cells when various 3′-UTRs are inserted at a BamHI site directly behind the luciferase coding sequence (LUC). An initial northern blot of RNA from BSF cells bearing integrated pMP revealed the presence of multiple RNA species recognized by a LUC probe (Fig 1B). The three bands indicated by arrowheads coincide with the locations of rRNAs and are likely due to entrapment of some luciferase RNA in these rRNAs. The RNA bands indicated by L (long), LUC and S (short) were examined further. To look for potential differential luciferase expression from the same inserted plasmid in BSF and PCF cells of the same * Corresponding author. Tel.: +1-319-335-7934; fax: +1-319-335-9570, Email address: E-mail: john-donelson@uiowa.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access NIH-PA Author ManuscriptNIH...

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“…also, transmissibility is not correlated with the parasitaemia but with the proportion of non-dividing stumpy forms that constitute the predominant population during the remission and relapse of the parasitaemia ( [Balber, 1972] and [Van den Bossche et al, 2005]). Such stumpy forms have the capacity to differentiate into procyclic forms either in the tsetse's midgut (Matthews, 1999) or in vitro (Breidbach et al, 2002) whereas long slender forms are not fit to survive in the insect vector and die rapidly after ingestion by the tsetse fly (Turner et al, 1988). Although such morphological changes are not observed in the monomorphic T. congolense strain used in this experiment, metabolic changes in the trypanosome could occur at each experimental stage and probably affect its capacity to infect tsetse flies.…”

Section: Discussionmentioning

confidence: 89%

Investigations on the transmissibility of Trypanosoma congolense by the tsetse fly Glossina morsitans morsitans during its development in a mammalian host

et al. 2008

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Experiments were conducted to investigate the effect of the developmental stage of a monomorphic T. congolense IL1180 strain, in a vertebrate host, on its transmissibility by the tsetse fly Glossina morsitans morsitans Westwood (Diptera: Glossinidae). Batches of 160 male teneral tsetse flies were given a single bloodmeal on mice infected with this T. congolense strain 4, 5, 6, 7 or 10 days post-infection. The proportion of infected flies in each of those batches showed that the stage of development of the trypanosome does affect the proportion of flies that develop a mature or immature infection with immature and mature infection rates of flies infected on days 5 or 10 significantly higher. The proportion of infected flies was not affected by the parasitaemia at the moment of infection. Results show that tsetse flies can become infected at any phase of the development of the T. congolense IL 1180 strain but the ease with which trypanosomes develop in the fly depends on the phase in the parasite's development in the host. Those observations suggest that in analogy with the pleomorphic T. brucei s.l. adaptation of the monomorphic T. congolense to development in the fly may also determine the parasite's transmissibility. Moreover, the findings stress the importance of standardising experiments in which the vectorial capacity of tsetse flies is determined and compared.

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Trypanosoma brucei: in vitro slender-to-stumpy differentiation of culture-adapted, monomorphic bloodstream forms

Cited by 31 publications

References 19 publications

Hydrolysis products of cAMP analogs cause transformation ofTrypanosoma bruceifrom slender to stumpy-like forms

Hydrolysis products of cAMP analogs cause transformation ofTrypanosoma bruceifrom slender to stumpy-like forms

Different trans RNA splicing events in bloodstream and procyclic Trypanosoma brucei

Investigations on the transmissibility of Trypanosoma congolense by the tsetse fly Glossina morsitans morsitans during its development in a mammalian host

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