Case Series: Report of the First Two Human Indigenous Cases of Cryptococcus gattii Infection in Eastern Canada.

We report the two first cases of human C. gattii meningoencephalitis acquired on the Canadian east coast, from the province of Quebec. Unlike C. neoformans, C. gattii is not known to have an established ecological niche on the North American east coast. C. gattii has recently been responsible for major outbreaks in British Columbia, Canada, and in the American pacific northwest. However, no human cases acquired in other Canadian provinces have been reported to our knowledge. The source of acquisition remains unclear for both patients but since neither had traveled outside of the province of Quebec, we discuss the possibilities of environmental and animal-associated acquisition, as well as the possible established endemicity in new areas. These cases add to the growing reported human and animal cases in areas previously not thought to be endemic for C. gattii.

IL-2 contributes to maintaining a balance between CD4+Foxp3+ regulatory T cells and effector CD4+ T cells required for immune control of blood-stage malaria infection.

To investigate the role of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells in blood-stage malaria, we compared Plasmodium chabaudi AS infection in wild-type (WT) C57BL/6 and transgenic mice overexpressing the transcription factor Foxp3 (Foxp3Tg) and observed that Foxp3Tg mice experienced lethal infection and deficient malaria-specific immune responses. Adoptive transfer of total CD4(+) T cells from Foxp3Tg mice or CD4(+)CD25(+) T cells from WT mice to naive WT recipients confirmed that high numbers of Treg cells compromised immune control of malaria. Transfer of GFP(+)CD4(+)CD25(+) T cells to naive WT recipients together with immunohistochemical staining of spleens from infected WT mice demonstrated that Foxp3(+) Treg cells localized in the T cell area of the spleen. Determination of CD4(+)Foxp3(+) Treg cell responses in the spleen of infected WT mice revealed a significant but transient increase in CD4(+)Foxp3(+) Treg cells early in infection. This was followed by a significant and sustained decrease due to reduced proliferation and apoptosis of CD4(+)Foxp3(+) Treg cells. Importantly, the kinetics of IL-2 secretion by effector CD4(+)Foxp3(-) T cells coincided with changes in CD4(+)Foxp3(+) cells and the differentiation of CD4(+)T-bet(+)IFN-γ(+) cells required for immune control of infection. Administration of the IL-2/anti-IL-2 mAb (clone JES6-1) complex to infected WT mice increased the severity of P. chabaudi AS infection and promoted expansion of Foxp3(+) Treg cells. Collectively, these data demonstrate that the ability to control and eliminate P. chabaudi AS infection is due to a tight balance between natural Treg cells and effector CD4(+) Th1 cells, a balance regulated in part by IL-2.

Comparing the regulation and incentivization of e-cigarettes across 97 countries.

E-cigarette use continues to increase globally despite uncertainty regarding their long-term health impacts and around their effectiveness for tobacco smoking cessation. This uncertainty creates unique challenges for governments as they attempt to optimally regulate and positively or negatively incentivize these products in a way that maximizes the public's health. Current approaches to e-cigarette regulation and incentivization fall within a spectrum of options ranging from a singular focus on health protection, whereby policies intend to prevent the dangers of e-cigarettes, to a singular focus on using e-cigarettes for harm reduction, whereby policies intend to reduce the more harmful effects of smoking tobacco. Regulation options include prohibition, component ban, and regulation as medicinal products, poisons, tobacco products, consumer products, and/or unique products. Incentivization options include taxation, subsidization, and providing a financial reward. Through comparative public policy analysis, this study describes, compares and assesses the variety of approaches that 97 countries have taken to regulate and incentivize e-cigarettes. The goal is to inform future decisions by governments on how they approach the public health challenge posed by e-cigarettes, building on a nuanced understanding of the complexities of this challenge and what other jurisdictions have already implemented and learned.

T regulatory cells control numbers of NK cells and CD8alpha+ immature dendritic cells in the lymph node paracortex.

The spleen contains numerous NK cells whose differentiation profile is characterized by a preponderance of mature elements located mainly in the red pulp. In contrast, lymph nodes (LNs) contain few NK cells and they are sited mostly in T cell zones and skewed toward immature developmental stages. We show that, in mice, naturally occurring CD4+ Foxp3+ regulatory T (Treg) cells are both necessary and sufficient to repress accumulation of NK cells in resting LNs. Moreover, we present evidence that Treg cells hamper generation of mature NK cells through short-range interactions with NK precursors. In turn, mature NK cells specifically regulate the amount of CD8alpha+ phenotypically immature dendritic cells present in LN T cell zones. We propose that the dominant influence of Treg cells on NK cell precursors and CD8alpha+ immature dendritic cells explains why "quiescent" LNs in the absence of infection function as privileged sites for induction and maintenance of tolerance to peripheral Ags.