Association of Lps gene with natural resistance of mouse macrophages against Legionella pneumophila

Abstract

Listen

Translate article

Peritoneal macrophages obtained from lipopolysaccharide (LPS)-low responder C3H/HeJ mice (J) permitted the intracellular growth of Legionella pneumophila after in vitro phagocytosis, while macrophages of LPS-high responder C3H/HeN mice (N) did not. Intracellular growth of the bacterium in macrophages of (J × N) F1 progeny was between the parent strains, showing that the traits were co-dominantly expressed. Correlation between intracellular bacterial growth in macrophages and LPS response of spleen cells was examined. Negative correlation was found between the two factors in F2, (J × F1) backcross and (N × F1) backcross progeny. This result implies that Lps gene controls the innate resistance of murine macrophages against the bacteria. Although macrophages of A/J strain also permit intracellular growth of L. pneumophila, gene complementation analysis of A/J and C3H/HeJ mice made clear that the gene control in C3H/HeJ differs from that of A/J strain. Macrophages of C57BL/10ScN, which is LPS-low responder line obtained from C57BL/10, were also defective in controlling the bacterial growth when compared to C57BL/10 mice. We suggest that the Lps gene also controls the natural resistance of murine macrophages against L. pneumophila.