BONE-MARROW CELLULAR COMPOSITION IN LISTERIA-MONOCYTOGENES INFECTED MICE DETECTED USING ER-MP12 AND ER-MP20 ANTIBODIES - A FLOW CYTOMETRIC ALTERNATIVE TO DIFFERENTIAL COUNTING

Detailed assessment of bone marrow cellular composition is essential i n the evaluation of various experimental in vivo systems, such as expr ession of transgenes, null mutations and stimulation of host defence i n infection. Traditional morphological analysis of mouse bone marrow i s laborious, requires specific cytological expertise, and is somewhat subjective. As an alternative, we have examined whether double labelli ng of bone marrow with the anti-precursor monoclonal antibodies ER-MP1 2 and ER-MP20 could be used for differential analysis by flow cytometr y, as these antibodies define six relatively homogeneous cell populati ons in mouse bone marrow Following a sublethal infection of mice with Listeria monocytogenes, we monitored changes in cellular composition o f the bone marrow at various time points in three ways: differential m orphological count; single-color flow cytometric analysis using marker s for the myeloid, erythroid and lymphoid lineages; and double labelli ng with ER-MP12 and ER-MP20. As expected, the bone marrow composition changed dramatically during infection leading to an increase of myeloi d cells which peaked after 1 week of Data determined by ER-MP12/20 flo w cytometric analysis appeared to be in close agreement with both morp hology and lineage marker analysis. In addition, ER-MP12/20 analysis p rovided more detailed information with regards to the presence of earl y myeloid precursors compared to lineage marker analysis. These data s how that flow cytometric analysis of bone marrow using ER-MP12 and ER- MP20 monoclonal antibodies provides a relatively simple, rapid and obj ective assay when evaluating cellular composition in the bone marrow o f the mouse. (C) 1998 Elsevier Science B.V. All rights reserved.