Characterization of anti-single-stranded DNA B cells in a non-autoimmune background.
Anti-DNA Abs are prevalent in the serum of systemic lupus erythematosus (SLE) patients and in the MRL-lpr/lpr mouse model of SLE, but are generally absent in normal individuals. We have studied the regulation of anti-ssDNA B cells in a non-autoimmune (BALB/c) background by using Ig transgenes (Tgs) encoding anti-DNA Abs. In one case, they are present with other non-DNA-binding B cells (the VH3H9 Tg with endogenous light chains); in the other, they are present as an essentially monospecific population (VH3H9/Vkappa8). We have previously observed that serum anti-ssDNA levels in these Tg mice were no higher than those of non-Tg mice, despite the fact that anti-ssDNA B cells dominate the peripheral B cell repertoire. These results suggested that the anti-ssDNA Tg B cells present are functionally inactivated. In this paper, we isolate B cells from VH3H9/Vkappa8 Tg mice to show that this is indeed the case and go on to further define this state. We demonstrate that VH3H9/Vkappa8 Tg B cells have diminished Ig secretion in response to both T-independent and T-dependent stimuli compared with non-Tg controls. VH3H9/Vkappa8 Tg B cells also show suboptimal proliferation in response to anti-IgM F(ab)'2 fragments and LPS, and are phenotypically distinct in expressing decreased total surface Ig. Despite their functional defects, however, VH3H9/Vkappa8 Tg B cells have an in vivo turnover rate comparable to non-Tg B cells, suggesting that they are long lived.
Nguyen
K A
KA
Wistar Institute, Philadelphia, PA 19104, USA.
Mandik
L
L
Bui
A
A
Kavaler
J
J
Norvell
A
A
Monroe
J G
JG
Roark
J H
JH
Erikson
J
J
D000818:Animals; D000974:Antibodies, Antinuclear / Q000276:immunology*; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology*; D004277:DNA, Single-Stranded / Q000276:immunology*; D018014:Gene Transfer Techniques; D007075:Immunoglobulin M / Q000276:immunology; D007136:Immunoglobulins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic
D000974:Antibodies, Antinuclear; D004277:DNA, Single-Stranded; D007075:Immunoglobulin M; D007136:Immunoglobulins