Detection, by direct lymphocyte immunocytotoxicity, of antigens in cells transformed by Rous virus]

The hamster cells transformed by the Rous Sarcoma Virus (V.S.R.) evidenced surface antigenic alterations that were detected by a method of cellular mediated immunocytotoxicity. Immune hamster lymphocytes were added to tritiated proline prelabeled target cells. These lymphocytes were able to lyse specifically the V.S.R. transformed cells.     

Cytotoxicity of human T-lymphocytes sensitized by Epstein-Barr virus. Role of HLA antigens at the surface of target cells infected by the virus]

Peripheral T-lymphocytes from patients with infectious mononucleosis are cytotoxic towards target cells from Epstein-Barr virus-genome carrying human lumphoblastoid lines. Thus, these T-cells appear to be sensitized to viral coded determinants. Daudi cells, that carry EBV-genome, but lack HLA antigens are resistant to specific cytolysis in this model. These results suggest direct HLA involvement in the target structure recognized by birus-sensitized cytolytic T-lymphocytes in human.     

Isolation of Myxovirus influenzae surface antigens by affinity chromatography]

Surface antigens of Myxovirus influenzas A/r8/34 and A/Hong Kong/1/68 were isolated on Fetuin covalently attached to Sepharose. The amino acid composition of isolated neuraminidases was determined.     

Effect of sodium butyrate on the interferon sensitivity of normal or cells transformed by murine sarcoma virus]

Sodium butyrate enhances the sensitivity of MSV transformed murine cells to interferon, but does not influence the response of normal cells. Sodium butyrate might act in transformed cells by restoring the different elements of the cytoskeletal system.     

Receptors for cytomegaloviruses on the surface of human lymphocytes]

The relationships between cytomegalovirus (CMV) and lymphocytes have already been noted because of: (a) the immunological abnormalities induced by this virus, and (b) activation of latent CMV in the course of lymphocyte reactions associated with anti-histocompatibility antigen immune response. The present work shows that the lymphocyte surface may have specific receptors for CMV. Cultured fibroblasts infected with DMV were incubated with lymphocytes isolated from the blood of human immune subjects. Rosettes defined by the adherence of three or more lymphocytes around a fibroblast were formed in infected preparation while no rosettes were seen with normal control fibroblasts. Approximately 1.2 per cent of lymphocytes were involved in the formation of these rosettes. Rosette formation is inhibited when infected fibroblasts have been incubated with anti-CMV antibodies prior to the addition of lymphocytes.     

Tumor specific surface antigen in the culture medium of a rat cell line transformed by Rous sarcoma virus]

TSSA is detected on transformed cells by a mixed hemadsorption reaction. The medium of cultures of Rat cells transformed by Rous sarcoma virus (Prague strain, sub-group C) contains a soluble factor which specifically inhibits this reaction. This factor thus possesses the antigenic activity of TSSA which is associated with the presence of a component of molecular weight 42,000 by polyacrylamide gel electrophoresis.     

Detection of antigens in the embryo by labelled antisera

Résumé Des anticorps contre le cristallin et contre le muscle cardiaque de la souris ont été marqués par le radio-iode, puis employés pour la localisation histochimique et pour une analyse quantitative de ces antigènes au cours du développement.     

Replication of immune RNA by human lymphoblastoid cells]

Animal immune RNA used for the induction of the human lymphoblastoid cell line LDV/7, induces the appearance of receptor sites on the surface of these cells and the synthesis of specific immunoglobulins which are liberated into the culture medium. Furthermore, RNA has been extracted from these cells, which possesses the same properties of specific cytotoxicity as the RNA used for induction. It is supposed that the immune RNA derepresses specific genes on the genome of the induced cells.     

Detection of antigens on filarial larvae by means of immune adherence

Résumé On a décelé des antigènes à la surface des larves deBreinlia sergenti par la réaction d'adhérence immune. Ils n'ont pas été décelés sur les adultes ni sur les microfilaires, avec un sérum de lapin anti-larves. L'antisérum a réagi avec les larves deDirofilaria immitis etBrugia pahangi, mais non pas avec les larves deBrugia malayi.     

Cytotoxicity of mouse peritoneal cells after alloimmunization]

CBA Mice were immunized by two intraperitoneal injections of 30 X 10(6) DBA/2 or C57BL/6 spleen cells at days--12 and--2. Peritoneal cell population was obtained at day zero by washing the peritoneal cavity of Mice. Adherent cells were then separated using a 2 hrs. incubation in "Falcon" plates followed by washing. This macrophage-rich peritoneal cell population was found nonspecifically cytotoxic against 51Cr labeled tumoral target cells: P815 X DBA/2 mastocytoma cells, EL4 X C57BL/L lymphoma cells and spontaneous lymphoma AKR cells (same H--2k as CBA). This adherent peritoneal cell cytoxicity was demonstrated after 24 hrs. incubation with the target cells. It was found in nonspecific combination as well as when using target cells syngeneic to the donor. These findings suggest that adherent peritoneal cell cytotoxicity could be at least partly due to macrophages and result from factor (s) released by sensitized lymphocytes in vivo in the same way as has been previously demonstrated in vitro.