T cell receptor V_β genes expressed by IgG anti‐DNA autoantibody‐inducing T cells in lupus nephritis: Forbidden receptors and double‐negative T cells

Abstract

In the (SWR x NZB)F1 (SNF1) model of lupus nephritis, pathogenic variety of IgG anti-DNA autoantibodies are induced by certain T helper (Th) cells that are either CD4+ or CD4-CD8- (double negative; DN) in phenotype. From the spleens of eight SNF1 mice with lupus nephritis, 149 T cell lines were derived and out of these only 25 lines (approximately 17%) were capable of augmenting the production of pathogenic anti-DNA autoantibodies. Herein, we analyzed the T cell receptor (TcR) V beta genes used by 16 such pathogenic autoantibody-inducing Th cell lines. Twelve of the Th lines were CD4+ and among these five lines expressed V beta 8 (8.2 or 8.3). The V beta 8 gene family is contributed by the NZB parent to the SNF1 mice, since it is absent in the SWR parental strain. Three other CD4+ Th lines expressed V beta 4, another was V beta 2+ and one line with poor autoantibody-inducing capability expressed V beta 1. Four autoantibody-inducing Th lines from the SNF1 mice had a DN phenotype and these lines were also autoreactive, proliferating in response to syngeneic spleen cells. Among these DN Th lines, two expressed V beta 6 and one expressed V beta 8.1 TcR. Both of these are forbidden TcR directed against Mls-1a (Mlsa) autoantigens expressed by the SNF1 mice and such autoreactive T cells should have been deleted during thymic ontogeny. Thus, the DN Th cells of non-lpr SNF1 mice are different from the DN cells or MRL-lpr which lack helper activity and do not express forbidden TcR. The spleens of 6 out of 19 nephritic SNF1 animals tested also showed an expansion of forbidden autoreactive TcR+ cells that were mainly DN. Two of these animals expressed high levels of V beta 6 (anti-Mlsa) and V beta 11 (anti-I-E) TcR+ cells, three others had high levels of V beta 11+ cells alone and one animal had an expanded population of V beta 17a+ (anti-I-E) cells. The I-E-reactive TcR again should have been eliminated in the SNF1 thymus, since they express I-E molecules contributed by the NZB parent. The SWR parents of SNF1, are I-E-; moreover, they lack the V beta 11 gene but they express V beta 17a in peripheral T cells. Whereas the NZB parents are I-E+, they lack a functional V beta 17a gene and they delete mature V beta 11+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Junctional region sequences of T-cell receptor beta-chain genes expressed by pathogenic anti-DNA autoantibody-inducing helper T cells from lupus mice: possible selection by cationic autoantigens.

“…Herein we report also cloning T-cell hybridomas after fusing CD4-enriched T cells (6-8) from the spleens of 6-to 7-mo-old nephritic SNF1 mice with the TCR a/,8-chain-negative variant of the BW5147 thymoma (9). To select for those T-cell lines and hybridomas that could preferentially augment the production of cationic, IgG-class anti-DNA autoantibodies, serial dilutions of T cells from each line or hybridoma were cultured with syngeneic B cells as described (6)(7)(8), except that the hybridoma T cells received 2200 rads (10) before coculture. Total polyclonal IgG (,ug/ml) or IgG-class autoantibodies (units/ml) to single-stranded DNA or doublestranded DNA produced in the cultures were quantitated by assaying separate aliquots from each culture supernatant as described (6-8).…”

“…Total polyclonal IgG (,ug/ml) or IgG-class autoantibodies (units/ml) to single-stranded DNA or doublestranded DNA produced in the cultures were quantitated by assaying separate aliquots from each culture supernatant as described (6-8). Cationic anti-DNA autoantibodies of IgG class were detected by affinity purification of culture supernatant aliquots on DNA-cellulose columns followed by isoelectric focusing (6)(7)(8).…”

“…Female mice were used. Cloned T-cell lines from nephritic SNF1 mice were derived as described (7,8). Herein we report also cloning T-cell hybridomas after fusing CD4-enriched T cells (6)(7)(8) from the spleens of 6-to 7-mo-old nephritic SNF1 mice with the TCR a/,8-chain-negative variant of the BW5147 thymoma (9).…”

“…twice, 7 days apart, with 107 or 2 x 107 T cells in 0.2 ml of Hanks' balanced salt solution. The T cells were first activated by stimulation with syngeneic, mitomycin C-treated antigen-presenting cells (APC) (7,8) …”

“…However, helper T-cell (Th-cell) subsets that are essential for inducing the production of these crucial pathogenic anti-DNA autoantibodies both in vivo and in vitro, appear only in the spleens of the SNF1 progeny just prior to the onset of lupus nephritis but not in young preautoimmune SNF1 mice or in the parental strains that do not develop nephritis (6)(7)(8). Although the antigenic specificities of such Th cells are unknown, we were able to clone them by means of their special functional property of inducing the production of pathogenic anti-DNA autoantibodies, and we report herein analysis of the T-cell receptor (TCR) 8 chains expressed by these pathogenic autoantibody-inducing Th cells.t…”