Peter Perlmann

Cytological observations on the cytotoxic interaction between lymphocytes and antibody-coated monolayer cells.

Abstract Chang cells in monolayers were killed when exposed to highly purified human peripheral blood lymphocytes in the absence of complement and in the presence of a concentration of heat inactivated rabbit anti-Chang cell serum (ACS) chosen for inability by itself to cause cytolysis. As evident by plaque formation, the cytotoxic reaction was confined to areas of the cultures covered with lymphocytes. In the presence of ACS, lymphocytes attached to and infiltrated the monolayers. Uropod formation indicated activation of the lymphocytes. Close contact was established between effector and target cells. The cytotoxic reaction was not accompanied by protracted cytopathological changes but led to detachment and rapid lysis of the target cells. Horse anti-thymocyte globulin, added to the cultures, completely inhibited plaque formation and lymphocyte infiltration.

Morphological observations on the cytotoxicity of human blood lymphocytes for antibody-coated chicken erythrocytes☆

Abstract Chicken erythrocytes, treated with sublytical concentration of heat inactivated rabbit antiserum, are destroyed by highly purified human peripheral blood lymphocytes. Morphological evidence supports the notion that the target cells are killed by a mechanism involving osmotic lysis. Opsonification of the target cells elicits a phagocytic activity of some cells with characteristic lymphocyte morphology. However, phagocytosis appears to be of minor importance for the cytotoxic reaction.

Differential cytotoxicity of activated lymphocytes on allogeneic and xenogeneic target cells. I. Activation by tuberculin and by Staphylococcus filtrate

Abstract Normal lymphocytes activated by mitogens such as phytohemagglutinin (PHA), by Staphylococcus filtrate (SF), or lymphocytes from sensitized individuals stimulated by antigen (PPD, etc.) are cytotoxic to tissue culture cells of different origins. In this and the following paper, the results of a detailed quantitative analysis of the specificity of this cytotoxic reaction are presented. Effector cells were human or mouse lymphocytes, activated by PHA, SF, PPD, or serum factors in the culture medium. Cells from established cell lines of human, mouse, hamster, or rabbit origin, or primary human or rat embryonic fibroblasts were used as target cells. Lysis was quantitated by release of 51 Cr from labeled target cells. Purified human blood lymphocytes, activated by PPD, SF, or otherwise, preferentially damaged allogeneic target cells. Lysis of xenogeneic target cells was weak or did not occur. A close correlation was noted between target cell destruction and blastoid transformation of the lymphocytes, but the slope of the regression lines of xenogeneic cytotoxicity was much smaller than that of allogeneic cytotoxicity when plotted as a function of blastoid transformation. Lymph node or spleen cells from CBA mice were stimulated by PPD to transformation and DNA synthesis. CBA lymphocytes also showed an increased degree of blast transformation in medium containing fetal calf serum or certain batches of fresh human serum. Mouse lymphocytes activated in these ways damaged allogeneic L cells but had no effects on xenogeneic Chang cells. These results indicate that lymphocytes activated by various means preferentially damage target cells from their own species. The recognition mechanisms which determine the specificity of the reactions are not known.

Ultrastructural features of in vitro propagated rat liver cells

SummaryBy morphological and functional selection of cultured rat liver cells, a cloned strain (PAR-C 1) of epithelial-like cells was established in vitro and investigated by light and electron microscopy. The morphological evidence presented suggested a parenchymal origin of the PAR-C 1 strain, which after 7 months of in vitro propagation was composed of rapidly proliferating and moderately dedifferentiated cells containing large Golgi zones, numerous cytosomes, cytosegresomes (“autophagic vacuoles”) and multivesicular bodies, moderate numbers of mitochondria and cisternae of ER, and abundant free ribosomes. The parenchymal cell origin was suggested by the occurrence of particulate glycogen in the cytoplasmic ground substance and the presence of specialized cell junctions typical of epithelial cells.The images obtained were consistent with the hypothesis that multivesicular bodies are formed in the vicinity of the Golgi apparatus through sequestration of vesicles in single membrane-limited bodies. These may carry acid phosphatase and other lysosomal enzymes; their participation in intracellular digestive events was suggested by the occurence of internal vesicles in cytosome-like bodies.The appearance, in the PAR-C 1 cells, of a “cytoskeleton” composed of bundles of filaments, similar to those encountered in the epithelial cells of bile ductules, might indicate a close morphogenetic relationship between the two types of cells.

Differential cytotoxicity of activated lymphocytes on allogeneic and xenogeneic target cells. II. Activation by phytohemagglutinin.

Abstract In the preceding paper it has been shown that human or mouse lymphocytes stimulated by a variety of agents, damaged allogeneic target cells while damage of xenogeneic target cells was weak or absent. In this study, the species specificity of the cytotoxicity of PHA activated lymphocytes has been studied in greater detail. Effector cells were purified lymphocytes either from human peripheral blood, or from spleen or lymph nodes of inbred mice. Target cells were 51Cr-labeled human Chang liver cells or mouse L cells. PHA stimulated human or mouse lymphocytes were significantly more cytotoxic to allogeneic than to xenogeneic target cells. At low PHA doses at which damage of allogeneic target cells was significant, damage of xenogeneic target cells was very weak or absent. At higher PHA doses, damage of xenogeneic target cells became also significant but always remained at a lower level than that of allogeneic target cells. Prestimulation of human lymphocytes with PHA for 3 days increased their cytotoxic efficiency. Furthermore, damage of human Chang cells by human lymphocytes had a dose-response relationship similar to that valid for stimulation of DNA synthesis. However, damage of mouse L cells by human lymphocytes increased at PHA-doses at which stimulation of DNA-synthesis declined. For mouse lymphocytes, these doseresponse relationships were less clear-cut, probably due to differences in origin and survival of the effector cells. This confirms previous observations that cytotoxicity and DNA-synthesis are different but probably interdependent expressions of lymphocyte activation.

VIRUS DEPENDENT NATURAL CYTOTOXICITY (VDCC) OF HUMAN LYMPHOCYTES

Publisher Summary This chapter examines virus dependent natural cytotoxicity (VDCC) of human lymphocytes. Treatment of lymphocytes with live or UV-inactivated virus enhances their cytotoxicity for a large variety of target cells. The effector cells appear to be heterogeneous. Which effector cells predominate in a given reaction depends on the type of target cells used. With some target cells, T-cells lacking Fc receptors for IgG are highly cytotoxic. Neither specific recognition of viral antigen nor mitogenic activation is required for VDCC induction. The experiments discussed in this chapter show that certain viral glycoproteins are efficient inducers of lymphocyte cytotoxicity, apparently not involving conventional immune recognition by humoral antibodies or specific T-cell receptors. These latter mechanisms are believed to affect the course of many virus infections by limiting the spread of the virus. Because VDCC is generated earlier than the conventional immune response, it may have an important protective function at the beginning of a virus infection. At the same time, because of its low selectivity, comprising both infected and noninfected targets, VDCC may also be a harmful tissue damaging factor, appearing in the course of a persisting infection.