TY - JOUR
T1 - Terminal B cell differentiation is skewed by deregulated interleukin-6 secretion in beta2 integrin-deficient mice
AU - Peters, Thorsten
AU - Bloch, Wilhelm
AU - Wickenhauser, Claudia
AU - Tawadros, Samir
AU - Oreshkova, Tsvetelina
AU - Kess, Daniel
AU - Krieg, Thomas
AU - Müller, Werner
AU - Scharffetter-Kochanek, Karin
PY - 2006/9/1
Y1 - 2006/9/1
N2 - Absence of the common beta chain (CD18) of beta(2) integrins leads to leukocyte-adhesion deficiency type-1 (LAD1) in humans. Mice with a CD18 null mutation suffer from recurrent bacterial infections, impaired wound healing, and skin ulcers, closely resembling human LAD1. Previous findings in CD18(-/-) mice demonstrated a skewed terminal B cell differentiation with plasmacytosis and elevated serum immunoglobulin G (IgG). As interleukin-6 (IL-6) is a potent enhancer of plasma cell formation and Ig secretion, we assessed IL-6 serum levels of CD18(-/-) and wild-type (WT) mice kept under a conventional or barrier facility or specific pathogen-free (SPF) conditions. We detected an up to 20-fold increase in IL-6 in serum of CD18(-/-) mice compared with WT controls when kept under conventional or barrier facility conditions, respectively. Under SPF conditions, no significant differences in terms of IL-6 serum levels were found between CD18(-/-) and WT mice. However, histological alterations of secondary lymphoid tissues, plasmacytosis, abnormal plasmacytoid cells (Mott cells), and hypergammaglobulinemia persisted. To further analyze the role of IL-6 in these pathological alterations, we established a CD18(-/-) IL-6(-/-) double-deficient mouse mutant. In these mice, serum IgG levels were normal, and the altered plasma cell phenotype, including Mott cells, was no longer detectable. The CD18(-/-) IL-6(-/-) double-deficient mouse model thus demonstrated that IL-6 is responsible for parts of the phenotype seen in the CD18(-/-) mouse mutants. It may be of interest to examine human leukocyte-adhesion deficiency type-1 patients closer and search for pathological changes possibly induced via overproduction of IL-6.
AB - Absence of the common beta chain (CD18) of beta(2) integrins leads to leukocyte-adhesion deficiency type-1 (LAD1) in humans. Mice with a CD18 null mutation suffer from recurrent bacterial infections, impaired wound healing, and skin ulcers, closely resembling human LAD1. Previous findings in CD18(-/-) mice demonstrated a skewed terminal B cell differentiation with plasmacytosis and elevated serum immunoglobulin G (IgG). As interleukin-6 (IL-6) is a potent enhancer of plasma cell formation and Ig secretion, we assessed IL-6 serum levels of CD18(-/-) and wild-type (WT) mice kept under a conventional or barrier facility or specific pathogen-free (SPF) conditions. We detected an up to 20-fold increase in IL-6 in serum of CD18(-/-) mice compared with WT controls when kept under conventional or barrier facility conditions, respectively. Under SPF conditions, no significant differences in terms of IL-6 serum levels were found between CD18(-/-) and WT mice. However, histological alterations of secondary lymphoid tissues, plasmacytosis, abnormal plasmacytoid cells (Mott cells), and hypergammaglobulinemia persisted. To further analyze the role of IL-6 in these pathological alterations, we established a CD18(-/-) IL-6(-/-) double-deficient mouse mutant. In these mice, serum IgG levels were normal, and the altered plasma cell phenotype, including Mott cells, was no longer detectable. The CD18(-/-) IL-6(-/-) double-deficient mouse model thus demonstrated that IL-6 is responsible for parts of the phenotype seen in the CD18(-/-) mouse mutants. It may be of interest to examine human leukocyte-adhesion deficiency type-1 patients closer and search for pathological changes possibly induced via overproduction of IL-6.
KW - Animals
KW - Antigens, CD18
KW - B-Lymphocytes
KW - Cell Differentiation
KW - Down-Regulation
KW - Immunoglobulin G
KW - Interleukin-6
KW - Lipopolysaccharides
KW - Macrophages
KW - Mice
KW - Mice, Inbred C57BL
KW - Mice, Knockout
U2 - 10.1189/jlb.1205740
DO - 10.1189/jlb.1205740
M3 - Journal articles
C2 - 16844762
SN - 0741-5400
VL - 80
SP - 599
EP - 607
JO - Journal of leukocyte biology
JF - Journal of leukocyte biology
IS - 3
ER -