Wild-type C57BL/6J female mice were purchased from Jackson Laboratory (Bar Harbor, ME) and maintained in a specific pathogen-free status in a 12 hours light/dark cycle. All procedures were conducted using mice 6–8 weeks of age maintained in ventilated microisolator cages housed in an American Association for Accreditation of Laboratory Animal Care (AAALAC) approved animal housing facility. Protocols and studies involving animals were conducted in accordance with National Institutes of Health guidelines and approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Pittsburgh.