Dominant tolerance is mediated by regulatory T cells (Treg) that control harmful autoimmune T cells in the periphery. In this study, we investigate the implication of Treg in modulating infiltrating T lymphocytes in human metastatic melanoma. We found that CD4+CD25high T cells are overrepresented in metastatic lymph nodes (LNs) with a 2-fold increased frequency compared with both tumor-free LNs and autologous PBMCs. These cells express the Foxp3 transcription factor, display an activated phenotype, and display a polyclonal TCR Vβ chain repertoire. They inhibit in vitro the proliferation and cytokine production of infiltrating CD4+CD25− and CD8+ T cells (IL-2, IFN-γ) through a cell-contact-dependent mechanism, thus behaving as Treg. In some cases, the presence of Treg type 1/Th3-like lymphocytes could also be demonstrated. Thus, Treg are a major component of the immunosuppressive microenvironment of metastatic melanoma LNs. This could explain the poor clinical response of cancer patients under immunotherapeutic protocols, and provides a new basis for future immunotherapeutic strategies counteracting in vivo Treg to reinforce local antitumor immune responses.

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We report here the characterization of a series of T cell receptor (TcR) V alpha or V beta subfamily-specific oligonucleotide primers. Criteria that have guided the design of each oligonucleotide include appropriate thermodynamic parameters as well as differential base-pairing scores with related and unrelated target sequences. The specificity of the oligonucleotides for each V alpha or V beta subfamily was tested by polymerase chain reaction (PCR) on both a series of TcR encoding plasmid DNA and clonal T cell populations. Unexpected cross-reactivities were observed with plasmid cDNA sequences corresponding to unrelated subfamily gene segments. This led to the synthesis of additional series of oligonucleotides to obtain a relevant panel. A series of V alpha 1-w29/V beta 1-w24 TcR subfamily-specific oligonucleotides was eventually selected which generates little, if any, cross-reactivity. The use of C alpha or C beta primers for the amplification of internal positive control templates (i.e. C beta for the V alpha series and C alpha for the V beta series) has been tested in PCR performed with cDNA derived from peripheral blood lymphocytes; it was shown not to alter the amplification of the V subfamily-specific DNA fragments. This panel of oligonucleotides will be helpful in the study of TcRV gene segment usage and, thus, may lead to a better characterization of T cell responses in physiological and pathological situations.

CitationSupervised versus unsupervised intake of six-dose artemether-lumefantrine for treatment of acute, uncomplicated Plasmodium falciparum malaria in Mbarara, Uganda: a randomised trial., 365 (9469 Articles IntroductionWith an estimated 500 million individuals affected every year, malaria is a leading cause of morbidity and mortality in sub-Saharan Africa along with HIV/AIDS. 1Of the 1 million deaths caused by malaria worldwide, about 90% occur in African children, a situation compounded by the emergence of drug resistance. 2In Uganda, which had a population of 24·7 million in 2003, an estimated 9·8 million individuals are infected with malaria every year (John Bosco Rwakimari, Ugandan Ministry of Health, Uganda, personal communication; http://www.health.go.ug). To tackle malaria-related mortality and morbidity, the Ugandan Ministry of Health (MoH) is concentrating on early diagnosis and effective treatment of the disease. In the 1970s and the 1980s, high malaria awareness in the population and easy access to cheap and effective antimalarials such as chloroquine and sulfadoxinepyrimethamine ensured the disease was reasonably well controlled. However, resistance to these drugs is now widespread in Uganda and in other parts of east Africa, with adverse consequences for malaria control. 3-7The MoH-recommended first-line antimalarial drug in Uganda is chloroquine combined with sulfadoxinepyrimethamine, 6 though introduction of artemisininbased combination treatments (ACTs) is planned for 2005.8 Day-28 cure rates of 52%, 9 65%, 7 and 77% 10 have been reported for this combination in different parts of Uganda. ACTs are judged effective in Africa, where they improve cure rates and reduce gametocyte carriage compared with presently used monotherapies.11,12 To combat drug-resistant malaria in Africa, WHO advocates the adoption of ACTs as first-line treatment.2 The use of the non-ACT combination of amodiaquine and sulfadoxine-pyrimethamine is considered by some as an interim measure while waiting for ACTs to become widely available. Day-28 efficacy rates of this combination were 84% and 90% in two studies in Uganda. 7,9 Artemether-lumefantrine (Coartem, Novartis Pharma, Basel, Switzerland) is the only fixed-dose formulation ACT on the WHO essential drug list. However, the combination is not registered for use in pregnant women, and was not registered for children under 10 kg in weight when we did our trial. Results of studies [13][14][15] from southeast Asia show that the six-dose regimen of artemether-lumefantrine has cure rates of more than 96%, is well tolerated, and has a good safety profile when Supervised versus unsupervised intake of six-dose artemether-lumefantrine for treatment of acute, uncomplicated Plasmodium falciparum malaria in Mbarara, Uganda: a randomised trial Patrice Piola, Carole Fogg, Francis Bajunirwe, Samuel Biraro, Francesco Grandesso, Eugene Ruzagira, Joseph Babigumira, Isaac Kigozi, James Kiguli, Juliet Kyomuhendo, Laurent Ferradini, Walter Taylor, Francesco Checchi, Jean-Paul Guthmann S...

Serum CPS screening among AIDS patients with a CD4+ count <100 cells/mm3 is useful in areas highly endemic for cryptococcosis, allowing early diagnosis and treatment of this opportunistic infection.

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Positive outcomes for d4T/3TC/NVP are reported for up to 18 months in terms of efficacy and safety.

Memory T cells are divided into central and effector subsets with distinct functions and homing capabilities. We analyzed the composition and dynamics of the CD8(+) T cell repertoire of these subsets within the peripheral blood of four healthy individuals. Both subsets had largely distinct and autonomous TCRbeta repertoires. Their composition remained stable over a 9 month period, during which no cell passage between these subsets was detected despite important size variation of several clones. In one donor, four out of six TCRbeta clonotypes specific for the influenza A virus were detected in the central subset only, while the two others were shared. Altogether, these observations suggest that most effector memory T cells may not have derived from the central memory subset.