Effects of on Engraftment of Patient-derived Chronic-Myelomonocytic Leukemia Cells in NSGS Mice.

Modeling chronic myelomonocytic leukemia (CMML) in immunodeficient NSGS mice relies on unique human CMML specimens and consistent murine engraftment. Only anecdotal comments have thus far supported the notion that research data may be altered by , an opportunistic cutaneous pathogen of immunodeficient mice. disseminated by asymptomatic and clinically affected mice with hyperkeratotic dermatitis, resulting in resilient facility contamination and infectious recurrence. Herein we report that, compared with PCR-negative counterparts, PCR-positive NSGS mice developed periocular and facial hyperkeratosis and alopecia and had reduced metrics indicative of ineffective human CMML engraftment, including less thrombocytopenia, less splenomegaly, fewer CMML infiltrates in histopathologic sections of murine organs, and fewer human CD45 cells in samples from murine spleen, bone marrow, and peripheral blood that were analyzed by flow cytometry. All CMML model metrics of engraftment were significantly reduced in the PCR-positive cohort compared with the negative cohort. In addition, a survey of comprehensive cancer center practices revealed that most murine facilities do not routinely test for or broadly decontaminate the facility or its equipment after a outbreak, thus increasing the likelihood of recurrence of invalidated studies. Our findings document that CMML engraftment of NSGS mice is diminished-and the integrity of murine research data jeopardized-by infection of immunodeficient mice. In addition, our results indicate that should be excluded from and not tolerated in murine facilities housing immunodeficient strains.