The present study examined the influence of the mouse Lps genotype on the
interleukin-6 (IL-6) and polymorphonuclear leucocyte (PMN) responses to mucosal
Escherichia coli infection.
Lipopolysaccharide (LPS) responder C57BL/6J (Lpsn, Lpsn) and LPS non-responder C57BL/10ScCr (Lpsd, Lpsd) mice were inoculated intravesically with Escherichia coli Hu734. The secretion of
IL-6, the recruitment of PMNs into urine, and the bacterial clearance from the kidneys and bladders were compared between the two mouse strains at 2, 6 and 24 h after
infection. The C57BL/6J mice showed a high PMN response and rapid clearance of bacteria from the kidneys and bladders. In the C57BL/10ScCr mice the PMN response was low and
infection remained. This supported a role of the Lps genotype in these events. The
IL-6 levels remained low after
infection in both LPS responder and non-responder mice, but became elevated in the animals which were accidentally traumatized during
infection. The
IL-6 response to
trauma alone was independent of Lps genotype, but the response to
trauma and
infection combined differed between the mouse strains. The
IL-6 response to
trauma and
infection was more rapid in the C57BL/6J than in the C57B1/10ScCr mice. The traumatized and infected animals did not clear the
infection as efficiently as the non-injured animals in both backgrounds. The difference in PMN recruitment and susceptibility of
infection between LPS responder and non-responder mice in the C57 Black background followed the pattern previously seen in the C3H mouse background and suggested that these events were under Lps gene control. An effect of the Lps locus on the
IL-6 response could be detected only in traumatized and infected animals.