The cytotoxic action of immune gamma globulin and complement on Krebs ascites tumor cells. I. Ultrastructural studies

Phospholipid synthesis in HeLa cells exposed to immunoglobulin G and complement

1. HeLa cells were cultured in the presence of heterologous immunoglobulin G and guinea-pig serum together with [(32)P]phosphate. 2. Incorporation of [(32)P]phosphate was significantly stimulated by anti-HeLa immunoglobulin G and complement-sufficient serum compared with immunoglobulin G from unimmunized rabbits and complement. Within 2.5h heat-inactivated guinea-pig serum and anti-HeLa immunoglobulin G stimulated [(32)P]phosphate incorporation to the same extent as heat-inactivated complement and immunoglobulin G from unimmunized rabbits. 3. Compared with cells exposed to immunoglobulin G from unimmunized rabbits together with complement, anti-HeLa immunoglobulin G with complement increased the phospholipid content of HeLa cells twofold within 5h of incubation. 4. Exposure of HeLa cells to anti-HeLa immunoglobulin G and complement for 5-22h resulted in a twofold increase in the net accumulation of [(32)P]phosphate in sphingomyelin and phosphatidylcholine and a 50% increase in the net accumulation of [(32)P]phosphate in phosphatidylethanolamine, compared with cultures exposed to immunoglobulin G from unimmunized rabbits and complement. 5. A transient accumulation of (32)P-labelled lysophosphoglycerides in HeLa cells exposed to antibody and complement was detected, confirming previous findings (Güttler & Clausen, 1969b). 6. The stimulation of [(32)P]phosphate turnover occurred in cells filling up their cytoplasma with vacuoles. This supports the suggestion that the accumulation of phospholipid in these cells may be concerned with the synthesis and function of cytomembranes.

Cytotoxic action of antiserum and complement: quantification with a colony inhibition method

Images

Production of ultrastructural membrane lesions by the fifth component of complement

A direct quantitative relationship has been demonstrated between the number of cell bound C4,2 complexes or C5 molecules and the number of ultrastructural lesions visualized on the cell membrane subsequent to immune hemolysis. When bound C4,2 complexes exceeded bound C5 molecules, the number of ultrastructural lesions seen corresponded to the number of C5 molecules. However, in the reverse situation, with bound C5 molecules in excess of bound C4,2 complexes, the latter determined the number of lesions. During the complement-reaction sequence, the lesions first became visible in the nonlytic intermediate complex EAC1,4,2,3,5 and their number was unaffected when lysis was induced by C6-C9. Since the lesions were also demonstrable on the intermediate complex EC5,6,7, it is concluded that the protein C5 is responsible for their production. Once formed, the physical presence of the C5 molecule is no longer required for the manifestation of the lesions as indicated by persistence of lesions after removal of C5 protein by trypsin. The C5-dependent ultra-structural phenomenon has therefore been interpreted to represent a true structural change of the membrane which, however, is not accompanied by a permeability defect.

Changes in lipid pattern of HeLa cells exposed to immunoglobulin G and complement

1. Immunoglobulin G was isolated from sera of non-immunized rabbits or rabbits immunized with whole HeLa cell homogenate. The anti-HeLa immunoglobulin G and its Fab fragment precipitated the particulate 400000g-min. fraction of HeLa cell homogenate. 2. Immunoglobulin G from immunized or non-immunized rabbits and fresh or inactivated complement were added to HeLa cell cultures. Changes in the cell count and cellular contents of DNA, RNA, protein, total and individual phospholipids, cholesterol (and esters) and ganglioside were followed. 3. Addition of immunoglobulin G from non-immunized rabbits and guinea-pig serum (complement) caused a transient increase in DNA followed by a permanent increase in RNA, protein, dry weight and number of cells per culture. 4. Addition of anti-HeLa immunoglobulin G and active complement caused an increase in the cellular content of cholesterol, total phospholipids, lysophosphatidylcholine and lysophosphatidylethanolamine greater than the increase of the controls and a decrease in the molar percentages of phosphatidylcholine and phosphatidylethanolamine as compared with the controls. 5. The cholesterol/phospholipid ratio remained constant. 6. The appearance of lysophosphoglycerides was transient, reaching a maximum 3hr. after addition of anti-HeLa immunoglobulin G. 7. The content of lysophosphoglycerides in HeLa cultures exposed to immunoglobulin G from non-immunized rabbits ranged from 50% to 30% of the values obtained from cultures exposed to the anti-HeLa immunoglobulin G and complement. 8. The changes in the lipid pattern of the HeLa cells were associated with the appearance of juxta-nuclear vacuoles in cells, but were apparently not specifically related to the presence of active complement.

The serum bactericidal system: ultrastructural changes in Neisseria meningitidis exposed to normal rat serum

Exposure of meningococci to the bactericidal system of normal rat serum initiates a series of ultrastructural changes that accompany death of the organism. These morphological alterations consist of complement-dependent holes in the cell wall outer membrane, edema of the periplasmic space and cytoplasm, and accumulation of fibrillar material in and on the cell wall. Dissolution of the dense line and rupture of the cytoplasmic membrane also occur in meningococci exposed to normal rate serum. These latter two changes, however, are not seen in meningococci that are killed by bentonite-absorbed (lysozyme-deficient) serum, nor are they invariably present when other serum-susceptible organisms (N. catarrhalis and Herellea sp.) are treated with normal rat serum. The pattern of development of edema in serum-treated meningococci suggests that the cell wall outer membrane, mucopeptide layer, and cytoplasmic membrane act synergistically to maintain osmotic equilibrium of the bacterium. Death of the bacterium seems related to alteration of permeability following injury to the outer membrane. Holes are demonstrable, by negative straining, in the outer membrane of the meningococcal cell wall after exposure to the bactericidal effects of rat serum. The lesions are 110 A average greatest diameter and depend on the presence of antibody and complement for their formation. In addition, 82 A diameter holes are present in the walls of normal, untreated meningococci. The relation of complement-dependent holes to the smaller, naturally occurring holes is not known.

Cerebral ischemia. III. Vascular changes

Images

Electrical recordings from meningioma cells during cytolytic action of antibody and complement

Resting membrane potential and total cell resistance of human meningioma cells in tissue culture have been measured with fine microelectrodes. Addition of either antiserum inactivated with heat or control serum from normal rabbits produced small depolarizations (2 to 4 millivolts) with no discernible ( 5 percent) change in resistance. Addition of antiserums with complement, however, produced larger depolarizations and decreases in resistance before any changes in cell morphology were visible with light microscopy; as cytoplasmic swelling progressed, membrane potential dropped close to zero, and resistance decreased five- to tenfold. The electrical recording technique may be useful in the study of sublethal as well as lethal damage to immune cells and, in particular, may permit temporal resolution of damaging events and repair mechanisms in a single cell.

Morphological changes induced in human red cells by rabbit univalent antibody

In an attempt to study size and shape variations induced in red cells by fixation of relatively large amounts of antibody protein in the absence of haemagglutination, microscopic analysis has been performed on human O red cells incubated with rabbit univalent anti-human red cell antibodies. These were obtained by recombining half-molecules of anti-red cell γG-immunoglobulin with half-molecules of non-specific γG-immunoglobulin.

Changes in cell morphology accounted essentially for a diameter increase during incubation at 37° in the presence of the recombined fraction. These changes were a progressive variation towards the sphere and then the disk shape. The amount of univalent material effective in determining such variation was estimated to be near to 45,000 molecules/cell, i.e. about twice the amount of bivalent molecules per cell giving 50 per cent agglutination.

The possibility that the mechanism of action of either the bivalent γG-immunoglobulin antibody or the recombined univalent molecule might be the same in respect to cytotoxicity is discussed.

The cytotoxic principle of the phytoflagellate Prymnesium parvum

The cytotoxic events leading to lysis induced in Ehrlich ascites tumor (E.A.) cells by Prymnesium parvum cell extracts were followed microscopically and measured quantitatively as changes in E.A. cell volume, uptake of trypan blue, and release of macromolecular constituents from the cells. Cell swelling was the most immediate response to P. parvum cytotoxin, while cell death and lysis were later events distinguished by a decline in cell volume, uptake of dye, and appearance of cellular macromolecules free in the incubation medium. The pH and temperature were shown to affect the outcome of the lytic sequence. At either low pH or temperature, cells swelled but did not lyse until the pH or temperature was raised. On the other hand, cells swollen at the higher pH or temperature could be protected from lysis by lowering either the pH or the temperature.

Studies on thyroid microsomal antigens

Images

Description and analysis of a simple micro-titration immune cytolytic test

Images

THE EFFECTS OF ANTIBODIES ON CELLS. I. BIOCHEMICAL AND HISTOCHEMICAL EFFECTS OF ANTIBODIES AND COMPLEMENT ON ASCITES TUMOUR CELLS

Biochemical and histochemical methods were used to study the interaction of antibodies and complement with mouse Ehrlich ascites tumour cells.

In the presence of complement, both iso- and hetero-antibodies caused cell lysis with penetration of antibodies into the damaged cells, as detected by immunofluorescence; the cells were then unable to support aerobic glycolysis though they retained their ability to consume oxygen in the presence of succinate. Under these conditions there was unmasking of phospholipid particularly at the cell surface, together with lysosomal changes resulting in diffuse staining for lysosomal acid—phosphatase.

In the absence of complement, antibodies did not appear to penetrate the cells which respired normally and were not lysed. However, in these cells there was intense lysosomal activation accompanied by unmasking of cytoplasmic phospholipid; it appeared that an immune reaction confined to the cell surface was able to induce changes in the cytoplasm without acutely impairing the viability of the cell.

Cytotoxic effects produced by the beta toxin of Clostridium welchii on guinea-pigs monocytes

The cytopathic effects of Cl. welchii β toxin on guinea-pig monocytes in vitro have been studied using the uptake of eosin-Y^* as evidence of cell death.

The experiments show that these effects are due to antigen—antibody reaction probably on the cell surface, and that these reactions are not dependent on the presence of complement. Monocytes can be actively sensitized in vivo, and passively sensitized in vitro. The serum used to passively sensitize the monocytes need not possess a precipitating antitoxin titre.

Comparable experiments using an ovalbumin antigen—antibody system produced the same cytopathic effects on the monocytes as those which occurred in the β toxin—cellular system.

Tissue culture studies of lymphoid tissue sensitized to skin homografts and explanted with donor tissue

Images

Azione Tossica Delle Diverse Frazioni Endocellulari Del Sarcoma Galliera Iniettate Nel Coniglio a Scopo Immunizzante

6 groups of rabbits have been submitted to immunizing treatment with mitochondria from rat liver or with horse serum (controls), and with mitochondria, nuclei and supernatant from Galliera sarcoma. The doses of antigen were equivalent as total nitrogen, and the experimental conditions were the same for all animals.

Whereas normal endocellular fractions, horse serum and supernatant from Galliera sarcoma did not give significant results, the tumour mitochondria and nuclei were demonstrated to exert a very high toxic action in the rabbit, causing, in particular, a diminution of total proteins, and especially of globulins.

Following the treatment with the antigens, two different immunitary reactions have been observed, one of which was characterized by an increase in total nitrogen and globulins (especially beta-2 and gamma), and the other by a decrease of the same substances.

Azione « in Vivo » Ed « in Vitro » Sul Sarcoma Galliera Di Sieri Di Animali Immunizzati Con Frazioni Cellulari Dello Stesso Tumore

Rabbits’ immune sera treated with endocellular fractions of sarcoma Galliera, isolated by fractioned centrifugation, were studied « in vivo » and « in vitro » in relation to their action on the tumour. Rabbit's sera immunized with nuclei and with the supernatant of sarcoma Galliera did not inhibit « in vivo » the development of the already established tumour in rats as well as the tumour implanted into the rat following the introduction of a dose of serum. On the other hand, rabbits’ sera immunized with mitochondria of sarcoma Galliera showed an «in vivo» toxic action on the already established sarcoma, leading to its complete regression. A dose of immune serum failed to prevent the « taking » of the tumour subsequently implanted into the rat. Rabbit serum immunized with mitochondria of sarcoma Galliera showed an « in vitro » toxic action on the mitochondria of the tumour itself.