Wiskott-Aldrich syndrome protein deficiency in B cells results in impaired peripheral homeostasis

in Blood (2008), 112(10), 4158-69

To more precisely identify the B-cell phenotype in Wiskott-Aldrich syndrome (WAS), we used 3 distinct murine in vivo models to define the cell intrinsic requirements for WAS protein (WASp) in central ... [more ▼]

To more precisely identify the B-cell phenotype in Wiskott-Aldrich syndrome (WAS), we used 3 distinct murine in vivo models to define the cell intrinsic requirements for WAS protein (WASp) in central versus peripheral B-cell development. Whereas WASp is dispensable for early bone marrow B-cell development, WASp deficiency results in a marked reduction in each of the major mature peripheral B-cell subsets, exerting the greatest impact on marginal zone and B1a B cells. Using in vivo bromodeoxyuridine labeling and in vitro funtcional assays, we show that these dificits reflect altered peripheral homeostasis, partially resulting from an impairment in integrin function, rather than a developmental defect. Consistent with these observations, we also show that : (1) WASp expression levels increase with cell maturaity, peaking in those subsets exhibiting the greatest sensitivity to WASp deficiency; (2) WASp+ murine B cells exhibit a marked selective advantage beginning at the late transitional B-cell stage; and (3) a similar in vivo selective advantage is manifest by mature WASp+ human B cells. Together, our data provide a better understanding of the clinical phenotype of WAS and suggest that gene therapy might be a useful approach to rescue altered B-cell homeostasis in this disease. [less ▲]

Sera from patients with anti-GBM nephritis including goodpasture syndrome show heterogenous reactivity to recombinant NC1 domain of type IV collagen alpha chains.

in Nephrology Dialysis Transplantation (1996), 11(11), 2215-22

BACKGROUND: Goodpasture (GP) syndrome is defined by the clinical association of pulmonary haemorrhage with rapidly progressive glomerulonephritis. The disease is caused by pathogenic autoantibodies ... [more ▼]

BACKGROUND: Goodpasture (GP) syndrome is defined by the clinical association of pulmonary haemorrhage with rapidly progressive glomerulonephritis. The disease is caused by pathogenic autoantibodies directed against type IV collagen, which is a major structural component of glomerular basement membranes (GBM). METHODS: The non-collagenous domains (NC1) of all six human type IV collagen alpha chains was produced in E. coli as recombinant fusion proteins with glutathione-S transferase. Sera from 10 patients with different types of anti-GBM nephritis, including GP syndrome, were tested for reactivity with the six proteins using immunoblotting of denatured and reduced proteins and ELISA without reduction. RESULTS: All 10 sera reacted with the alpha 3 (IV) collagen chain by immunoblotting and ELISA. One serum also recognized the alpha 2(IV), alpha 4(IV), alpha 5(IV) and alpha 6(IV) chains by immunoblotting. ELISA measurements revealed reactivity of several other sera with alpha 2(IV), alpha 4(IV) or alpha 6(IV) but not with alpha 5(IV) collagen chains. No reactivity was observed with the alpha 1(IV) chain. CONCLUSION: Autoantibodies in anti-GBM nephritis may not be directed only against the alpha 3(IV) collagen chain and they frequently recognize conformational epitopes. [less ▲]

Anti-GBM antibodies from patients with Goodpasture Syndrome react with the NC1 domain of recombinant alpha3 (IV) and alpha4 (IV) collagen chains

in Journal of the American Society of Nephrology [=JASN] (1993), 4