T cell receptor junctional regions of V gamma 9+/V delta 2+ T cell clones in relation to non-MHC restricted cytotoxic activity.

Human gamma delta T cell clones having V gamma 9JP and V delta 2DJ1 T cell receptor (TCR) gene rearrangements were isolated form an individual donor and tested for non-MHC restricted cytotoxicity against the B lymphoblastoid cell line, BSM. Most clones were highly cytotoxic but 3/9 clones had very low activity, comparable to that of CD4+ alpha beta T cell clones. Although there was a tendency for clones with low cytotoxic function to produce high levels of interferon-gamma and tumor necrosis factor-alpha, this correlation was not complete. TCR gamma and delta junctional sequences were obtained and were found to be different for all clones. There were no consistent structural differences between gamma delta TCRs of cytotoxic and non-cytotoxic clones, but gamma or delta junctional regions of all three non-cytotoxic clones had unusual features. One clone had a particularly short gamma chain junctional sequence, one had a short delta chain junctional sequence and the third clone was the only one of the panel which failed to utilise the D delta 3 segment. If the gamma delta TCR is involved in target cell recognition in this model of non-MHC restricted killing, such variations in receptor structure may be sufficient to inhibit recognition and thereby reduce the cytotoxic capacity of a minority of V gamma 9+/V delta 2+ clones. Also, a panel of gamma delta T cell clones expressing V gamma 8/V delta 3 isolated from a different donor, were all highly cytotoxic against BSM, indicating that these target cells can be recognised by effector cells expressing a TCR other than the V gamma 9/V delta 2 receptor. The possible influence of other cell surface molecules on non-MHC restricted cytotoxic function is discussed.

Identification of ovarian antibodies by immunofluorescence, enzyme-linked immunosorbent assay or immunoblotting in premature ovarian failure.

The development of new techniques for the detection of ovarian antibodies has challenged early concepts about the rarity of ovarian antibodies in idiopathic premature ovarian failure (POF), but few attempts have been made to compare results between assays. We have sought to define the prevalence of ovarian autoimmunity in a group of 30 idiopathic POF patients compared to a group of 12 patients with POF plus an associated autoimmune disease and a group of 38 controls, using an enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IFL). Ovarian antibodies were detected in 27% of idiopathic POF patients by ELISA (not significantly different compared to POF patients with associated autoimmune disease; P < 0.0003 compared to controls) but only 7% of these patients were positive by IFL. In a further, pre-selected group of individuals, all positive for ovarian antibodies by IFL, 53% had measurable antibodies by ELISA. Some overlap was therefore demonstrated between the two techniques but many POF patients had ovarian antibodies detectable by only one method. Immunoblotting studies revealed that no consistent pattern of binding could be demonstrated for these patients. These results call into question the specificity of ovarian antibodies as a marker for autoimmune POF.

Detection of antibodies to ovarian antigens in women with premature ovarian failure.

Premature ovarian failure is a common condition of uncertain aetiology in most cases, although autoimmunity is thought to play a role in a proportion of cases. The frequency of ovarian antibodies, which may be markers for an autoimmune aetiology in this condition, remains unclear. To define this further, we have examined the sera of 45 women with premature ovarian failure (five with iatrogenic ovarian failure, nine with an associated autoimmune disease, and 27 with idiopathic ovarian failure), as well as four women with infertility due to Turner's syndrome and 41 pre- and post-menopausal controls. Using two human ovarian antigen preparations, 24% and 60% of the ovarian failure patients reacted in an ELISA (P < 0.05 and P < 0.001 compared with controls), but frequent cross-reactivity was found with fallopian tube antigens. The apparent aetiology of ovarian failure did not correlate with the presence of ovarian antibodies. Using bovine ovary as an antigen, there was a significant overall increase in binding by the ovarian failure patients, but this was almost identical to binding in an ELISA with bovine fallopian tube. In contrast to a previous report, there was no significant increase of binding to soluble or Triton-extracted membrane fractions of bovine corpora lutea containing the LH/hCG receptor by the patients with ovarian failure. These results suggest that ovarian antibodies are common in premature ovarian failure, but their specificity and pathogenic role are questionable.

Is subclinical ovarian failure an autoimmune disease?

Young women with unexplained infertility who exhibit elevated basal serum follicle stimulating hormone (FSH) concentrations (>10 IU/l) have poor outcomes in in-vitro fertilization. A subgroup of these women has regular menses, representing 'subclinical' ovarian failure, which may have an autoimmune basis and could potentially be treated by immunosuppression. To investigate this further, a range of immunological markers was used to assess autoimmune activity in 14 women aged <40 years with elevated FSH compared with 15 infertile women with normal FSH and 10 pre-menopausal, healthy controls. All samples were taken during natural menstrual cycles. Organ-specific antibodies against ovary, endometrium and thyroid, and non-organ-specific antibodies against histones and cardiolipin, were not significantly increased in elevated FSH patients compared with other control groups. Soluble CD23 and soluble intercellular adhesion molecule concentrations were not elevated in the sera of the women tested, and circulating T cell subsets remained unaltered. Significantly, increased concentrations of the complement breakdown product C3a and terminal complement complexes were detected in the elevated FSH group compared with the normal FSH group, although the latter also had significant complement activation compared with laboratory controls. Autoimmunity appears as an infrequent cause of 'subclinical' ovarian failure, but there is evidence of activation of complement in the sera of infertile women.

T-cell receptor Vbeta gene usage by lymphocytes infiltrating human renal allografts.

T cell lines have been derived from human kidney allograft biopsies using mitogenic stimulation. Southern blotting using a T-cell receptor (TCR) Cbeta probe revealed an oligoclonal pattern of rearranged bands in all 12 samples analysed. In some cases, differences in band patterns were noted between independent cultures from the same biopsy. Most T-cell clones derived from 2 biopsies showed different patterns of rearranged bands. The polymerase chain reaction (PCR) was used to study TCR Vbeta gene usage in allograft-derived T-cell cultures. This was more sensitive and more informative than Southern blotting and revealed that most TCR Vbeta genes were expressed in T cells from biopsies showing cellular rejection. The potential usefulness of this technique to quantify TCR V gene usage in allospecific T-cell populations is discussed.