TY - JOUR
T1 - The upper and lower respiratory tracts differ in their requirement of IFN-γ and IL-4 in controlling respiratory mycoplasma infection and disease
AU - Woolard, Matthew D.
AU - Hodge, Lisa M.
AU - Jones, Harlan P.
AU - Schoeb, Trenton R.
AU - Simecka, Jerry W.
PY - 2004/6/1
Y1 - 2004/6/1
N2 - The purpose of this study is to evaluate the significance of IFN-γ and IL-4 production in controlling mycoplasma infection and the pathogenesis of disease in the upper and lower respiratory tract. By using IFN-γ knockout and IL-4 knockout BALB/c mice, we were able to study the contribution of these cytokines in the development of pathogenesis and/or protection in response to mycoplasma respiratory infection, in both the upper and lower respiratory tracts. The loss of either IFN-γ or IL-4 does not affect disease pathogenesis or mycoplasma organism numbers in the upper respiratory tract. However, in the absence of IL-4, the nasal passages developed a compensatory immune response, characterized by higher numbers of macrophages and CD8 + T cells, which may be masking detrimental effects due to IL-4 deficiency. This is in contrast to the lower respiratory tract, where the loss of IFN-γ, but not IL-4, leads to higher mycoplasma numbers and increased disease severity. The loss of IFN-γ impacted the innate immune system's ability to effectively clear mycoplasma, as the number of organisms was higher by day 3 postinfection. This higher organism burden most likely impacted disease pathogenesis; however, the development of Th2 cell-mediated adaptive immune response most likely contributed to lesion severity at later time points during infection. Our studies demonstrate that the upper and lower respiratory tracts are separate and distinct in their cytokine requirements for generating immunity against mycoplasma infection.
AB - The purpose of this study is to evaluate the significance of IFN-γ and IL-4 production in controlling mycoplasma infection and the pathogenesis of disease in the upper and lower respiratory tract. By using IFN-γ knockout and IL-4 knockout BALB/c mice, we were able to study the contribution of these cytokines in the development of pathogenesis and/or protection in response to mycoplasma respiratory infection, in both the upper and lower respiratory tracts. The loss of either IFN-γ or IL-4 does not affect disease pathogenesis or mycoplasma organism numbers in the upper respiratory tract. However, in the absence of IL-4, the nasal passages developed a compensatory immune response, characterized by higher numbers of macrophages and CD8 + T cells, which may be masking detrimental effects due to IL-4 deficiency. This is in contrast to the lower respiratory tract, where the loss of IFN-γ, but not IL-4, leads to higher mycoplasma numbers and increased disease severity. The loss of IFN-γ impacted the innate immune system's ability to effectively clear mycoplasma, as the number of organisms was higher by day 3 postinfection. This higher organism burden most likely impacted disease pathogenesis; however, the development of Th2 cell-mediated adaptive immune response most likely contributed to lesion severity at later time points during infection. Our studies demonstrate that the upper and lower respiratory tracts are separate and distinct in their cytokine requirements for generating immunity against mycoplasma infection.
UR - http://www.scopus.com/inward/record.url?scp=2442640280&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.172.11.6875
DO - 10.4049/jimmunol.172.11.6875
M3 - Article
C2 - 15153506
AN - SCOPUS:2442640280
SN - 0022-1767
VL - 172
SP - 6875
EP - 6883
JO - Journal of Immunology
JF - Journal of Immunology
IS - 11
ER -