Trypanosoma brucei: A rapid “matching” method for estimating the host's parasitemia

Herbert, W.J.; Lumsden, W. H. R.

doi:10.1016/0014-4894(76)90110-7

Cited by 609 publications

(430 citation statements)

References 4 publications

Supporting

Mentioning

422

Contrasting

Unclassified

Order By: Relevance

“…The parasitemia was estimated by counting the number of parasites present in at least 10 fields at ϫ400 magnification by phase-contrast microscopy. A count of 256 parasites per field is equivalent to ϳ10 9 parasites/ml (21). To test for infection of the blood of anti-CD25 Ab-treated mice, which were subsequently infected i.f.p.…”

Section: Infection Estimation Of Parasitemia and Survival Timementioning

confidence: 99%

Regulatory T Cells Prevent Control of Experimental African Trypanosomiasis

Wei

Tabel

2008

The Journal of Immunology

View full text Add to dashboard Cite

African trypanosomes are single-cell, extra-cellular blood parasites causing profound immunosuppression. Susceptible BALB/c mice infected s.c. into a footpad with 104 Trypanosoma congolense die with fulminating parasitemia within 10 days. We injected BALB/c mice 2 days before such an infection with different doses of a depleting mAb specific for CD25, a surface marker of regulatory T cells (Tregs). Pretreatment with a low, optimal dose of anti-CD25 resulted in a dramatic effect, in that the infected mice did not develop parasitemia, as well as eliminated all parasites and showed no signs of disease. Their spleens showed a 100% reduction of CD4+CD25high T cells and overall a 70% reduction of CD4+CD25+Foxp3+ T cells 7 days postinfection. The protective effect of treatment with an optimal dose of anti-CD25 could be reversed by administration of l-N6-(1-imminoethyl) lysine, a specific inhibitor of inducible NO synthase or administration of anti-CD8 Ab. Analysis of the cytokine patterns and cell surface marker in infected mice pretreated with anti-CD25 Abs pointed to a potential NKT cell response. We then conducted infections in CD1d−/− mice. From our observations, we conclude that CD4+CD25highFoxp3+ Tregs prevent, in normal infected susceptible mice, an early protective response mediated by CD8+ NKT cell-dependent activation of macrophages to kill parasites by production of NO. Our results also indicate that different populations of NKT cells have protective or suppressive effects. Our observations lead us to propose a hypothesis of cross-regulation of NKT cells and Tregs in trypanosome infections.

show abstract

Section: Infection Estimation Of Parasitemia and Survival Timementioning

confidence: 99%

Regulatory T Cells Prevent Control of Experimental African Trypanosomiasis

Wei

Tabel

2008

The Journal of Immunology

View full text Add to dashboard Cite

show abstract

“…When used at 50 mg/kg, about 50% of parasites were immobilized, while 100 mg/kg of the extract immobilized 90% of the parasites, the response of the cold water extract of P. bicalyculata was dose-dependent. The standard drug, diminazine aceturate completely immobilized the parasites after 20 min incubation. The hot water extract of P. bicalyculata at 100 mg/ kg immobilized over 70% of the parasites after 40 min of incubation, and the percentage immobilized parasites did not increase even after 60 min, whereas no parasite was motile 25 min after incubation with the standard drug.…”

Section: Discussionmentioning

confidence: 98%

“…All extracts were prepared at three concentrations (25,50 and 100 mg/ mL), while 10 mg/mL of diminazeneaceturate was used. Aliquot of 30 毺 L of the extracts and standard was incubated with 40 毺 L of the infected blood containing about parasites per field [20] in wells of microtitre plates (Flow laboratories Inc., Mclean, Virginia 22101, USA). For the control, phosphate buffer saline (pH 7.4) was used.…”

Section: In Vitro Anti-trypanosomal Screening Of Extracts and Fractiomentioning

confidence: 99%

Anti–trypanosomal effect of Peristrophe bicalyculata extract on Trypanosoma brucei brucei–infected rats

Abimbola

Baba

Yenusa

et al. 2013

Asian Pacific Journal of Tropical Biomedicine

View full text Add to dashboard Cite

“…From the third day after the infection onwards, the parasitaemia of each mouse was measured daily using the scale of Herbert and Lumsden (1976). On days 4, 5, 6, 7 or 10 post-infection, four mice were selected randomly from the pool.…”

Section: Experimental Designmentioning

confidence: 99%

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

et al. 2008

View full text Add to dashboard Cite

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.

show abstract

Trypanosoma brucei: A rapid “matching” method for estimating the host's parasitemia

Cited by 609 publications

References 4 publications

Regulatory T Cells Prevent Control of Experimental African Trypanosomiasis

Regulatory T Cells Prevent Control of Experimental African Trypanosomiasis

Anti–trypanosomal effect of Peristrophe bicalyculata extract on Trypanosoma brucei brucei–infected rats

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

Contact Info

Product

Resources

About