Supplementary Material for: Tissue-Specific Patterning of Host Innate Immune Responses by <b><i>Staphylococcus aureus</i></b> α-Toxin

Immunomodulatory cytotoxins are prominent virulence factors produced by <i>Staphylococcus aureus</i>, a leading cause of bacterial sepsis, skin infection, and pneumonia. <i>S. aureus </i>α-toxin is a pore-forming toxin that utilizes a widely expressed receptor, ADAM10, to injure the host epithelium, endothelium, and immune cells. As each host tissue is characterized by a unique composition of resident cells and recruited immune cells, the outcome of α-toxin-mediated injury may depend on the infected tissue environment. Utilizing myeloid lineage-specific <i>Adam10</i> knockout mice, we show that α-toxin exerts tissue-specific effects on innate immunity to staphylococcal infection. Loss of ADAM10 expression exacerbates skin infection, yet affords protection against lethal pneumonia. These diverse outcomes are not related to altered immune cell recruitment, but rather correlate with a defect in toxin-induced IL-1β production. Extension of these studies through analysis of ADAM10 double-knockout mice affecting both the myeloid lineage and either the skin or lung epithelium highlight the prominence of toxin-induced injury to the epithelium in governing the outcome of infection. Together, these studies provide evidence of tissue specificity of pore-forming cytotoxin action in the modulation of host immunity, and illustrate that the outcome of infection is a collective manifestation of all effects of the toxin within the tissue microenvironment

Rural and Urban Differences in Welfare Exits: Minnesota Evidence 1986-1996

This article examines differences between rural and urban counties in the duration of welfare spells. We report evidence that suggests that parents from farming-dependent counties and rural counties are more likely to have shorter spells on welfare. The evidence appears consistent with the literature on rural low-income families in that there may be a concentration of low-wage jobs in rural counties. The difference between rural and urban areas is relevant to welfare policy as it pertains to caseload numbers, parents more likely to reach the sixty-month time limit, and parents more likely to trigger time-based policies, such as employment search. The study uses administrative data of Aid to Families With Dependent Children recipients from the state of Minnesota between 1986 and 1996. The methodology includes constructing descriptive statistics, calculating Kaplan-Meier estimates, and performing a Cox regression analysis with robustness checks across all three methods. Copyright 2005 Blackwell Publishing Ltd..