Immunohistochemical evidences showing the presence of thymulin containing cells located in involuted thymus and in peripheral lymphoid organs.

Thymulin is a well-characterized thymic hormone that exists as a nonapeptide coupled to equimolar amounts of Zn2+. Thymulin is known to have multiple biological roles, including T cell differentiation, immune regulation, and analgesic functions. It has been shown that thymulin is produced by the reticulo-epithelial cells of the thymus, and it circulates in the blood from the moment of birth, maintain its serum level until puberty diminishing thereafter in life. To study the localization of this hormone, we prepared polyclonal and monoclonal antibodies against the commercial peptide and utilized immunocytochemical techniques for visualization. The results indicate that thymulin stains the thymic reticular cells, the outer layers of Hassall's corpuscles and a large round cellular type, which is keratin-negative and does not show affinity for the common leukocyte antigen (CD-45). In mice, this thymulin-positive cell remains in the thymus throughout life and even appears in relatively increased numbers in old involuted thymi. It also appears in thymus-dependent areas of the spleen and lymph nodes, demonstrating that at least one of the thymus cells containing this peptide can be found in peripheral lymphoid tissue.

Immunohistochemical evidences showing the presence of thymulin containing cells located in involuted thymus and in peripheral lymphoid organs

Thymulin is a well-characterized thymic hormone that exists as a nonapeptide coupled to equimolar amounts of Zn2+. Thymulin is known to have multiple biological roles, including T cell differentiation, immune regulation, and analgesic functions. It has been shown that thymulin is produced by the reticulo-epithelial cells of the thymus, and it circulates in the blood from the moment of birth, maintain its serum level until puberty diminishing thereafter in life. To study the localization of this hormone, we prepared polyclonal and monoclonal antibodies against the commercial peptide and utilized immunocytochemical techniques for visualization. The results indicate that thymulin stains the thymic reticular cells, the outer layers of Hassall's corpuscles and a large round cellular type, which is keratin-negative and does not show affinity for the common leukocyte antigen (CD-45). In mice, this thymulin-positive cell remains in the thymus throughout life and even appears in relatively increased numbers in old involuted thymi. It also appears in thymus-dependent areas of the spleen and lymph nodes, demonstrating that at least one of the thymus cells containing this peptide can be found in peripheral lymphoid tissue.

Preparación y caracterización de un complejo peroxidasa-antiperoxidasa monoclonal / Preparation and characterization of a peroxidase-antiperoxidase monoclonal complex

En el presente trabajo se describe la obtención de un anticuerpo monoclonal de rata antiperoxidasa y la preparación, con esta inmunoglobulina, de un complejo peroxidasa-antiperoxidasa (PAP). Este complejo puede ser usado como reactivo en la detección de antígenos celulares en cortes de tejido o de antígenos solubles unidos a soporte sólido. El hibridoma obtenido produce anticuerpo antiperoxidasa de clase IgG, y al ser combinado con su antígeno, mediante la técnica descrita por Landsdorp, se obtiene un complejo PAP, que mayoritariamente presenta pesos moleculares entre 230.000 y 250.000, sugeriendo una composición Ag2-Ac1. También se forma una pequeña proporción de complejos mayores, que pueden llegar a pesar más de 7 x 10 elevado a 5. El complejo PAP preparado es estable y da reacciones en histoquímica de extraoridinaria limpieza