Systemic T helper 2 cell activation is not sufficient for antigen-induced eosinophil recruitment into the airways.
BACKGROUND
Airway eosinophilic inflammation is a characteristic feature of asthma. We have previously shown that antigen-induced eosinophil recruitment into the airways of sensitized BALB/c mice is mediated by CD4+ T cells and IL-5. However, the basis for the eosinophil recruitment into the airway are still largely unknown.


METHODS
To determine the regulatory mechanisms that control the magnitude of antigen-induced eosinophilic inflammation in the airways, we analyzed antigen-induced eosinophil and T cell infiltration into the trachea in several strains of mice, including BALB/c (H-2(d)), BALB/b (H-2(b)), C57BL/6 (H-2(b)), C57BL/10 (H-2(b)), and B10.D2 (H-2(d)) mice. In addition, cytokine production from antigen-stimulated splenocytes and the titer of antigen-specific IgE antibody in serum were assessed.


RESULTS
Antigen-induced eosinophil recruitment into the trachea in BALB/c mice was more than 20 times as abundant as that in C57BL/6 mice, the latter of which was also mediated by CD4+ T cells. In contrast, systemic Th2 responses, which were evaluated by the titers of antigen-specific IgE antibody in serum and antigen-induced IL-4 and IL-5 production from splenocytes, were similarly observed in BALB/c mice and C57BL/6 mice. In addition, the antigen-induced eosinophil recruitment into the trachea was high in BALB/b mice, like BALB/c mice, but low in B10.D2 mice.


CONCLUSIONS
Systemic Th2 responses are not sufficient for causing antigen-induced eosinophil recruitment into the airways and an undefined determinant(s) that exists in the BALB background mice rather than the H-2 haplotype is vital for the regulation of antigen-induced eosinophil recruitment into the airways.
Nakajima
H
H
Department of Internal Medicine II, Chiba University School of Medicine, Chiba, Japan.
Nakao
A
A
Kumano
K
K
Yamamoto
H
H
Iwamoto
I
I
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D002465:Cell Movement; D004804:Eosinophils / Q000502:physiology*; D005260:Female; D007371:Interferon-gamma / Q000502:physiology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D013045:Species Specificity; D018418:Th2 Cells / Q000276:immunology*; D014132:Trachea / Q000473:pathology*
D007371:Interferon-gamma; D010047:Ovalbumin