Preserving a Legacy.

When a nonprofit hospital is bought by a for-profit health care system, a central concern for boards is preserving the charitable mission, values and legacy of their organization.

Purpose-driven philanthropy. The path to financial sustainability also can lead trustees to greater fulfillment.

Not just a viable source of revenue, charitable giving can create another meaningful role for trustees.

Replication and distribution of Toxoplasma gondii in the small intestine after oral infection with tissue cysts.

Natural infection by Toxoplasma gondii occurs via oral ingestion of tissue cysts that rupture in the small intestine, releasing zoites that infect locally before disseminating throughout the host. The studies presented here used fluorescent parasites combined with flow cytometry and multiphoton microscopy techniques to understand the events associated with parasite replication in the mucosa. At 3 days postinfection with tissue cysts, parasites were localized in small foci and flow cytometry revealed parasites present in macrophages, neutrophils, and monocytes in the lamina propria.

Nucleotide oligomerization domain-containing proteins instruct T cell helper type 2 immunity through stromal activation.

Although a number of studies have examined the development of T-helper cell type 2 (Th2) immunity in different settings, the mechanisms underlying the initiation of this arm of adaptive immunity are not well understood. We exploited the fact that immunization with antigen plus either nucleotide-binding oligomerization domain-containing proteins 1 (Nod1) or 2 (Nod2) agonists drives Th2 induction to understand how these pattern-recognition receptors mediate the development of systemic Th2 immune responses. Here, we show in bone-marrow chimeric mice that Nod1 and Nod2 expression within the stromal compartment is necessary for priming of effector CD4(+) Th2 responses and specific IgG1 antibodies.

IL-27 regulates homeostasis of the intestinal CD4+ effector T cell pool and limits intestinal inflammation in a murine model of colitis.

IL-27 limits CD4(+) T(H)17 cell development in vitro and during inflammatory responses in the CNS. However, whether IL-27-IL-27R interactions regulate the homeostasis or function of CD4(+) T cell populations in the intestine is unknown. To test this, we examined CD4(+) T cell populations in the intestine of wild-type and IL-27R(-/-) mice.

MHC class II-dependent basophil-CD4+ T cell interactions promote T(H)2 cytokine-dependent immunity.

Dendritic cells can prime naive CD4+ T cells; however, here we demonstrate that dendritic cell-mediated priming was insufficient for the development of T helper type 2 cell-dependent immunity. We identify basophils as a dominant cell population that coexpressed major histocompatibility complex class II and interleukin 4 message after helminth infection. Basophilia was promoted by thymic stromal lymphopoietin, and depletion of basophils impaired immunity to helminth infection.

TSLP regulates intestinal immunity and inflammation in mouse models of helminth infection and colitis.

Intestinal epithelial cells (IECs) produce thymic stromal lymphopoietin (TSLP); however, the in vivo influence of TSLP-TSLP receptor (TSLPR) interactions on immunity and inflammation in the intestine remains unclear. We show that TSLP-TSLPR interactions are critical for immunity to the intestinal pathogen Trichuris. Monoclonal antibody-mediated neutralization of TSLP or deletion of the TSLPR in normally resistant mice resulted in defective expression of Th2 cytokines and persistent infection.

Welcome to the neighborhood: epithelial cell-derived cytokines license innate and adaptive immune responses at mucosal sites.

There is compelling evidence that epithelial cells (ECs) at mucosal surfaces, beyond their role in creating a physical barrier, are integral components of innate and adaptive immunity. The capacity of these cells to license the functions of specific immune cell populations in the airway and gastrointestinal tract offers the prospect of novel therapeutic strategies to target multiple inflammatory diseases in which barrier immunity is dysregulated. In this review, we discuss the critical functions of EC-derived thymic stromal lymphopoietin (TSLP), interleukin-25 (IL-25), and IL-33 in the development and regulation of T-helper 2 (Th2) cytokine-dependent immune responses.

Commensal-dependent expression of IL-25 regulates the IL-23-IL-17 axis in the intestine.

Alterations in the composition of intestinal commensal bacteria are associated with enhanced susceptibility to multiple inflammatory diseases, including those conditions associated with interleukin (IL)-17-producing CD4(+) T helper (Th17) cells. However, the relationship between commensal bacteria and the expression of proinflammatory cytokines remains unclear. Using germ-free mice, we show that the frequency of Th17 cells in the large intestine is significantly elevated in the absence of commensal bacteria.

Diverse myeloid and lymphoid cell subpopulations produce gamma interferon during early innate immune responses to Francisella tularensis live vaccine strain.

Francisella tularensis, a small gram-negative intracellular bacterium responsible for causing tularemia, is highly pathogenic and classified as a category A agent of bioterrorism. As for other intracellular pathogens, successful protective immune responses to Francisella tularensis require rapid and efficient induction of gamma interferon (IFN-gamma) production. Studies using intracellular bacteria such as Listeria monocytogenes as well as Francisella suggest that natural killer (NK) and T cells are important sources of IFN-gamma.

Epithelial-cell-intrinsic IKK-beta expression regulates intestinal immune homeostasis.

Intestinal epithelial cells (IECs) provide a primary physical barrier against commensal and pathogenic microorganisms in the gastrointestinal (GI) tract, but the influence of IECs on the development and regulation of immunity to infection is unknown. Here we show that IEC-intrinsic IkappaB kinase (IKK)-beta-dependent gene expression is a critical regulator of responses of dendritic cells and CD4+ T cells in the GI tract. Mice with an IEC-specific deletion of IKK-beta show a reduced expression of the epithelial-cell-restricted cytokine thymic stromal lymphopoietin in the intestine and, after infection with the gut-dwelling parasite Trichuris, fail to develop a pathogen-specific CD4+ T helper type 2 (T(H)2) response and are unable to eradicate infection.