Induction of microsomal antigen and comparison with histologic localization of HLA-DR in Graves' thyroid tissue.

We have characterized thyroid microsomal antigen (M-Ag) prepared from Graves' and normal thyroid tissues using 100,000 x g thyroid membrane fractions in enzyme-linked immunosorbent assays with pooled polyclonal human sera containing high titers of antibody to M-Ag. A ten-fold parallel increase in dose inhibition potencies occurred with M-Ag preparations from Graves' as compared to normal thyroid tissue. The M-Ag preparations were further evaluated by SDS-polyacrylamide gel electrophoresis and proteins visualized by Western blot using high titer microsomal antibody (M-Ab) sera (n = 2) devoid of thyroglobulin antibody activity. We found discrete 100 kD relative molecular mass bands in Graves' M-Ag preparations (n = 3) under nonreducing conditions which were only poorly resolved in normal thyroid M-Ag (n = 3) using up to 100 micrograms of protein per lane. The cellular localization of M-Ag was then investigated using the avidin-biotin-peroxidase technique on frozen sections of Graves' and normal human thyroid tissue with a murine monoclonal antibody reactive with human M-Ag and thyroid peroxidase. M-Ag reactivity was similar in both Graves' and normal thyroid tissues and localized to the entire follicular cell membrane with more intense staining occurring on the inner follicular cell membrane. This was in contrast to follicular cell staining for HLA-DR antigen which was present in 6 of 10 Graves' tissues examined and absent in normal thyroid tissue. Staining for HLA-DR antigen also occurred on the follicular cell surface membrane with occasional enhancement at the thyrocyte apical cell membrane. We conclude: a) M-Ag is induced approximately 10-fold in Graves' thyroid tissue and can be objectively quantified in ELISA systems, 2) There were no detectable qualitative differences between M-Ag from Graves' and normal thyroid tissue, and 3) HLA-DR antigen was detected on 60% Graves' tissues in a cell surface distribution similar to that observed for M-Ag in both Graves' and normal tissues.

Thymocyte maturity in male and female hypogonadal mice and the effect of preoptic area brain grafts.

Hypogonadal mice with a genetic deficiency of gonadotropin-releasing hormone (GnRH) have low levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and gonadal steroids. In this study we found differences from normal mice in many aspects of thymic development. Thymus weights and cellularity were higher in hypogonadal than in normal male mice but lower in hypogonadal than in normal females. Although all normal mice had higher proportions of mature, single staining thymocytes (CD8+ or CD4+) than seen in hypogonadal mice, there was a sex difference in the basis for this shift. Significantly more double-staining (CD8+, CD4+) thymocytes were seen in hypogonadal males than in normal males while both groups had similar single-staining populations. However, in females, both single-staining CD8+ and CD4+ thymocytes were more numerous in normal than in hypogonadal females while numbers of double-staining cells were similar in the two groups. These studies indicate that a mature thymocyte profile may be arrived at through differential effects of reproductive hormones in males and females. When brain grafts containing GnRH cells were used to correct reproductive deficits in hypogonadal mice, there were higher splenocyte counts in males with grafts, a similar trend in females, and a lower ratio of single staining CD4+ to CD8+ thymocytes in all females with grafts vs. all females without, regardless of whether or not the grafts corrected the reproductive hormone status of the recipients, indicating an effect of the graft surgery on the immune system.

A glycoprotein inhibitor of in vitro granulopoiesis associated with AIDS.

Patients infected with the human immunodeficiency virus (HIV) often present with neutropenia. To elucidate the mechanism(s) of this HIV-related neutropenia, we assessed the proliferative capacity of the granulocyte-macrophage progenitor cell (CFU-GM) from the bone marrow (BM) of 78 patients within the AIDS spectrum manifesting symptoms or signs related to HIV infection. Of these, 70 had a significant deficit in the growth of this committed progenitor when compared with normal controls (P less than .01). Further analysis revealed that the nucleated bone marrow cells from AIDS and AIDS-related complex (ARC) patients inhibited the growth of CFU-GMs from normal individuals when cocultured in agar (P less than .001). Control CFU-GMs were also inhibited when they were cultured over feeder layers containing patients' BM cells (P less than .001). Conditioned media obtained from the liquid culture of patients' BM cells did not inhibit normal control CFU-GM growth to a degree different from that of the cells themselves (P greater than .4). Analysis of these conditioned media by polyacrylamide gel electrophoresis (PAGE) revealed a unique glycoprotein (gp) with a mol wt of 84 kd. Further studies revealed that this gp possessed the inhibitory activity. These data suggest that this gp may be an important factor in HIV-related neutropenia. The presence of gp84 was independent of drugs administered to the patients.

Opportunistic infections in acquired immune deficiency syndrome result from synergistic defects of both the natural and adaptive components of cellular immunity.

We evaluated the cellular immunity of 408 clinically stratified subjects at risk for acquired immune deficiency syndrome (AIDS), to define the role of interferon-alpha production deficits in the pathogenesis of opportunistic infections (OI). We followed 115 prospectively for up to 45 mo. Onset of OI was associated with, and predicted by, deficiency both of interferon-alpha generation in vitro, and of circulating Leu-3a+ cells. Interferon-alpha production is an index of the function of certain non-T, non-B, large granular lymphocytes (LGL) that are independent of T cell help. Leu-3a+ cell counts are a marker of T cell function. OI did not usually develop until both of these mutually independent immune functions were simultaneously critically depressed, leading to a synergistic interaction. These data suggest that the AIDS virus affects a subset of LGL, and that cytokine production by these cells is an important component of the host defense against intracellular pathogens that becomes crucial in the presence of severe T cell immunodeficiency.

Immune thrombocytopenia and Gaucher's disease.

A 35-year-old Ashkenazi woman with Gaucher's disease was evaluated for persistent thrombocytopenia. The diagnosis of Gaucher's disease was made by bone marrow aspiration and confirmed by the determination of glucocerebrosidase levels in leukocytes and cultured skin fibroblasts. Studies of platelet-associated IgG and in vivo platelet survival demonstrated immune-mediated destruction of platelets consistent with immune thrombocytopenic purpura. A trial of prednisone had no effect on the platelet count. Total splenectomy resulted in a complete and prolonged remission. The clinical implications of Gaucher's disease and concurrent immune thrombocytopenic purpura are discussed.

Retention of HLA antigens on previously frozen human platelets.

Recent technical achievements allow satisfactory cryopreservation of human platelets that, after thawing and washing, maintain functional viability for therapeutic use. We have now demonstrated that such previously frozen platelets retain full HLA antigenic activity in spite of the combination of freezing, thawing, and washing procedures and the presence of the surface-active cryopreservative DMSO. Platelets stored at 4 C without DMSO and previously frozen platelets from the same donors were tested in parallel for quantitative expression of HLA antigens. In all cases, the previously frozen platelets were quantitatively equal or superior to the platelets stored at 4 C with regard to their capacity to specifically reduce the HLA antibody activities of selected typing sera against a panel of antigen-positive lymphocytes.