The proliferative response of human lymphocytes to stimuli such as foreign histocompatibility antigens or mitogens is generally assessed by measuring the amount of tritiated thymidine which the cells incorporated in culture. In this paper, the possibility of assessing lymphocyte proliferation and viability by an empirical assay, using measurement of light absorbance on a ELISA reader in the yellow wave length (450 nm/air-550 nm/air), has been studied. The correlation of these measurements with a colormetric viability assay using MTS/PMS, with tritiated thymidine incorporation and with trypan blue exclusion viability counting, was determined. The results showed that the light absorbance assay correlated well with cell proliferation during 48-120 hours culture period and with cell viability after a 72 hour period. The MTS/PMS colormetric assay as well as trypan blue exclusion cell counting confirmed that the light absorbance assay was not merely caused by dead cells. This data confirm that the light absorbance assay is sufficiently sensitive to low levels of proliferation to allow detection of such responses at least as effectively as thymidine incorporation. The light absorbance assay procedure avoids the expense, time and hazards associated with scintillation counting, and is simple to perform without the necessity for reagents and preparative steps required by other assays.

Adolescent↗

PubMedDate not supplied

Autoantibodies to thyroglobulin in health and disease.

Thyroglobulin (Tg)--a heavily glycosylated, iodinated protein--is a major autoantigen in autoimmune thyroiditis. Tg also induces thyroiditis by immunization of experimental animals. Humans with chronic lymphocytic thyroiditis characteristically produce autoantibodies to thyroglobulin, but similar autoantibodies are also found in some clinically normal, euthyroid individuals. A comparison of the fine specificity of autoantibodies in humans and in experimentally immunized mice was carried out, based on their ability to inhibit a panel of monoclonal antibodies (MAbs). Patients with autoimmune thyroid disease, as well as normal individuals, produced autoantibodies mainly to the conserved, cross-reactive determinants of thyroglobulin. Patients developed additional autoantibodies to species-restricted epitopes. The determinants recognized by patients with Graves' disease differed in some respects from epitopes recognized by thyroiditis patients or patients with differentiated thyroid carcinoma. Similarly, mice that are genetically susceptible to thyroiditis produced autoantibodies that reacted with the mouse-specific antigenic determinants. Using an autoantibody that reacts with one of the epitopes associated with thyroiditis, a reactive 15-kDa fragment of human Tg--localized at the carboxy end of the molecule--was isolated and sequenced. Iodine plays an important role in the precise specificity of the disease-associated epitope, since T cells from patients with thyroiditis react with iodinated but not noniodinated human thyroglobulin. Addition of iodine to Tg generates new or exposes cryptic epitopes. Use of a selected MAb as a surrogate for the T-cell receptor suggests that a specific iodine-containing epitope is sometimes involved in recognition. Finally, thyroglobulin-reactive autoantibodies exhibit proteolytic activity on thyroglobulin.

Animals↗

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Immunologic restoration of thymectomized mice by thymus cell suspensions and the duration of their effect.

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Animals↗

PubMedDate not supplied

Immunological consequences of vasectomy: a review.

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Animals↗

PubMedDate not supplied

Induction of donor major histocompatibility complex antigens in coronary arterial vessels: mechanism of arterial vasculitis in rat allografts treated with cyclosporine.

Recently, a potentially lethal pattern of vascular rejection has been described in heart transplant patients treated with cyclosporine. The purpose of this study was to identify potential immune mechanisms responsible for the development of coronary vascular injury associated with acute rejection. Our hypothesis was that changes in histocompatibility (MHC) expression induced by immunosuppressive therapy with cyclosporine plays an important role in directing an immune response to the arterial bed. With the ACI to Lewis allograft model, we compared the histology and immunohistology of both unmodified allograft rejection at days 2, 3, and 4 after transplantation, and allograft rejection modified by pretreatment with cyclosporine. Both models exhibit histologic evidence of early rejection before extensive myocyte necrosis is seen. Unmodified early rejection develops rapidly and is associated with dense MHC class I antigen expression on both myocytes and venous endothelium. Cyclosporine-modified rejection develops more slowly and is characterized by an arterial vasculitis. This modified pattern of rejection is associated with increased myocardial expression of MHC class II antigens with the arterial bed preferentially expressing increased MHC antigens. It is interesting to speculate that in the setting of a slower developing rejection process, the preferential expression of MHC antigens within the arterial bed produces a delayed-type hypersensitivity response directed toward either the endothelium and/or adjacent MHC class II expressing myocytes. A prolonged periarterial and intraluminal inflammatory reaction may then produce a true vasculitis, which may be detrimental to the survival of the graft.

Animals↗

PubMedDate not supplied

Autoimmune endocrinopathies.

A great deal of understanding of the human autoimmune endocrinopathies has come from studies of thyroiditis in experimental animals. Three such models are available: induced thyroiditis produced by injections of thyroglobulin plus adjuvant; spontaneous thyroiditis in genetically susceptible animals; and thyroiditis resulting from manipulation of the immunological apparatus. The major lessons learned from studies of experimental animals are (i) autoimmune disease is multifactorial and polygenic; (ii) one or more genes regulating the immune response are associated with the major histocompatibility complex (Mhc) of the particular species; (iii) genetic control of tissue damage is more restricted than control of autoantibody formation; (iv) the Mhc controls T-cell proliferation to the autoantigens; (v) a distinct population of T cells prevents the development of organ-specific autoimune disease; (vi) the suppressor population emigrates from the thymus at a time and rate different from the helper populations; (vii) the suppressor population is more susceptible to low levels of irradiation and to cytotoxic effects of antiserum to Lyt-1 than is the helper population.

Animals↗

PubMedDate not supplied

Immunochemical studies of prostatic acid phosphatase.

Immunologic specificity of the prostatic acid phosphatase (PAP) and the kinetics of the PAP-anti-PAP antibody interactions were studied in detail. Antigenic identity of electrophoretic isozymes of PAP was established in this study. Counterimmunoelectrophoretic assay, radioimmunoassay, and immunofluorescence technique were developed to detect PAP and PAP-synthesizing cells. These techniques were applied to the determination of serum PAP levels and to the identification of metastatic prostate cancer cells in biopsies.

Acid Phosphatase↗

PubMedDate not supplied

Cultivation of epithelial cells from the prostate.

We have (a) examined culture conditions for prostatic cells, (b) devised a procedure for the selective enrichment of epithelial cells, and (c) developed a way to identify prostatic epithelial cells by immunologic methods.

Acid Phosphatase↗