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Biomedical subjects

H Wekerle

Publications and source records attributed to H Wekerle.

At least 217 records · Page 12Linked to original sources
PubMed1976

Experimental autoimmune orchitis: in vitro induction of an autoimmune disease.

Experimental autoimmune orchitis (EAO) can be induced in vitro. Normal lymph node lymphocytes cultured with autologous dissociated testis cells form rosette-like aggregates and later undergo blast transformation and proliferation. These stimulated lymphocytes cause in vivo EAO lesions, when injectd into syngeneic recipients. Moreover, their autoimmune reactivity can be monitored by an in vitro cytostasis assay. Density gradient analysis of the early lymphocyte-testis cultures reveals that the autoimmune reactive lymphocytes are enriched in the rosette populations. It therefore appears that testicular self-antigens are recognized by clonally preformed autologous lymphocytes.

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PubMed1975

Induction of T-cells differentiation in vitro by thymus epithelial cells.

Thymus-reticular epithelial cells (TE-cells) were grown in a cell culture devoid of any lymphocytic elements. These cells were able to induce T-cell differentiation in spleen cells from T-dificient mice as expressed by con-A responsiveness and GvH reactivity. It was also shown that xenogeneic rat TE cells were as effective in the induction of T-cell differentiation in vitro as syngeneic TE cells. This system is therefore ideal for the study of T-cell development.

Animals↗
PubMed1975

Thymus-derived rat lymphocyte receptor for cell surface antigens is a nonserologically defined product of the major histocompatibility gene complex.

Recognition of cell surface antigens by nonsensitized thymus-derived rat lymphocytes is not affected by antisera against immunoglobulin, yet can be effectively blocked by treatment of the lymphocytes with alloantisera raised against lymphoid cells. However, allo antisera induced by nonlymphoid cells do not inhibit recognition. Adsorption of blocking antisera on immunoglobulin-Sepharose columns does not decrease their blocking activity. Absorption of blocking alloantisera with liver and kidney homogenates removes the cytotoxic alloantibodies, yet does not affect the capacity of the antisera to block recognition. Anti-H1-1 alloantisera block antigen recognition only of lymphocytes of strains that share the H1-1 locus. These results suggest that the constant part of the thymus-derived lymphocyte receptor for cell-surface antigens is a product of the rat major histocompatibility locus, which is not identical with the serologically defined antigens.

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PubMed1973

Regulation of autosensitization. The immune activation and specific inhibition of self-recognizing thymus-derived lymphocytes.

We studied the mechanisms underlying the natural tolerance of thymus-derived (T) lymphocytes for self-antigens. Lymphocytes from the thymus or lymph nodes of inbred rats were autosensitized in vitro against monolayers of autochthonous thymus reticulum cells or syngeneic fibroblasts. Receptors for self-antigens were detected by the specific adherence of normal lymphocytes to syngeneic cells. The achievement of active cell-mediated autosensitization was assayed by measuring the immunospecific lysis of syngeneic target cells in vitro, or graft-versus-host (GvH) reactions in vivo. The following observations were made using these systems. (a) A fraction of normal lymphocytes was found to have specific surface receptors that are able to recognize self-antigens which seem to be accessible in vivo. These potentially self-reactive lymphocytes were activated by incubation with syngeneic or autochthonous cells in vitro. Hence, the elimination of potentially self-reactive lymphocytes cannot be the only basis for natural self-tolerance. Therefore, the maintenance of self-tolerance in vivo appears to involve suppression of the immune reactivity of such self-tolerant lymphocytes. (b) We found that control of autosensitization depends upon the inhibition of the recognition of self-antigens. A GvH reaction in vivo could not be suppressed once recognition of self-antigens had occurred in vitro. Moreover, studies of the kinetics of antigen recognition indicated that several hours of incubation in vitro were needed for the inactivation of factors specifically inhibiting self-recognition. (c) We found that factors which inhibit self-recognition are present in fresh autologous serum. Treatment of the lymphocytes, but not syngeneic adsorbing cells, with autologous serum prevented recognition of syngeneic antigens. Allogeneic serum did not prevent self-recognition, and autologous serum did not inhibit the recognition of foreign antigens. These findings indicate that natural tolerance of T lymphocytes to self-antigens can be regulated by serum factors which act on the lymphocytes. The immunospecificity of the inhibitory effect suggests that these factors may be soluble self-antigens in a tolerogenic form.

Animals↗
PubMed1972

Autosensitization of lymphocytes against thymus reticulum cells.

Lymph nodes of normal rats contain lymphocytes that can be induced in vitro to mediate a specific cellular immune reaction against reticulum cells derived from syngeneic adult thymus glands. It is likely that these lymphocytes had access to reticulum cell antigens during the period in which they developed immunocompetence within the thymus. This suggests that contact with self-antigens during development may not eliminate self-reactive lymphocytes. These findings are in conflict with the theory that natural tolerance to self-antigens depends upon elimination of lymphocyte clones.

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