Severity of disease caused by Leishmania major depends on the genetics of the host. Early induction of T helper cell type 1 (Th1)-type responses in resistant C57BL/6 mice and T helper cell type 2 (Th2) in susceptible BALB/c mice is thought to determine cure or disease respectively. We have mapped three loci that confer susceptibility or resistance upon congenic mice on the C57BL/6 or BALB/c backgrounds. Here we examine the histopathology and production of interleukin 4 (IL-4) and interferon gamma (IFN-γ) in the skin and draining lymph nodes in the congenic and parental mice. We show an evolving granuloma with a staged infiltration of inflammatory cells, but no difference between the groups. As an indication of an early-polarised Th1/Th2 response we measured IFN-γ and IL-4 in the lymph nodes and found no difference between any of the mice during the first 48 h. During infection, the level of IL-4 correlated with the lesion size, indicating that IL-4 reflects the disease severity rather than controls it. Considering this effect, B6.C(lmr1,lmr2) mice had similar cytokine levels to the parental C57BL/6 mice despite increased susceptibility and C.B6(lmr1,lmr2) were similar to BALB/c despite increased resistance. We conclude that the lmr loci affect disease severity by a mechanism independent of conventional helper T-cell responses. © 2004 Nature Publishing Group All rights reserved.

Item Type:	Refereed Article
Research Division:	Medical and Health Sciences
Research Group:	Clinical Sciences
Research Field:	Infectious Diseases
Objective Division:	Health
Objective Group:	Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:	Infectious Diseases
Author:	Foote, SJ (Professor Simon Foote)
ID Code:	34962
Year Published:	2004
Web of Science® Times Cited:	13
Deposited By:	Menzies Centre
Deposited On:	2005-08-01
Last Modified:	2007-05-29
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