Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells

Prostacyclin release and cytotoxicity of peritoneal cells are inversely related in pregnant and non-pregnant mice infected with herpes simplex virus

Cytotoxicity of peritoneal cells in a HSV-infected murine model is attenuated in late pregnancy. Prostacyclin (PGI2) is elevated at this time in reproductive tissues and has been implicated in the regulation of the immune response. The purpose of this study was to estimate PGI2 in the peritoneal wash or culture supernatants of peritoneal cells obtained from uninfected and HSV-infected pregnant and virgin mice using a radioimmunoassay for 6-keto-prostaglandin F1 alpha. The peritoneal wash of uninfected pregnant and virgin mice contained high levels of 6-keto-PGF1 alpha, 505 +/- 51 pg/100 microliters, (mean +/- S.E., n = 15), and 200 +/- 19 pg/100 microliters, (n = 30), ad did peritoneal effector and target cell cultures (1,159 +/- 118 pg/100 microliters, n = 6, and 1,057 +/- 207 pg/100 microliters, n = 7), respectively. HSV-infection induced in vitro cytotoxicity and suppressed the release of 6-keto-PGF 1 alpha (r = -0.897, P less than 0.05, n = 18). Its concentration was significantly higher (14-fold, P less than .05) in the peritoneal wash, but not in the cell culture, of pregnant (212 +/- 29 pg/100 microliters, n = 19) as compared to virgin mice (18.5 +/- 3.4 pg/100 microliters, n = 27). The levels of 6-keto-PGF1 alpha were inversely correlated (P less than .05) with the combined effects of HSV-infection and cytotoxicity.

Natural killer cytotoxicity and antibody-dependent cell cytotoxicity to herpes simplex virus-infected target cells in murine pregnancy

In vitro natural killer cytotoxicity (NKC) and antibody-dependent cell cytotoxicity (ADCC) activity against herpes simplex virus (HSV)-infected cells were evaluated in a pregnant murine model (C57Bl6 inbred strain). Virgin (n = 16) and pregnant (late gestation) mice (n = 15) were infected intraperitoneally with HSV, type 1. After 18 hr, a 0.5-ml aliquot of the peritoneal wash was frozen for virus plaque assay, and the cells were cultured in the 51chromium release assay for NKC and ADCC. %NKC (mean +/- S.E.) to HSV-infected targets was significantly suppressed (P less than 0.05) in pregnant mice, 10.3% +/- 1.9, compared to that of virgin mice, 32.5% +/- 2.5. This suppression was abrogated with HSV-specific antisera (%ADCC); 53.9% +/- 4.4 (pregnant) compared to 49.1% +/- 3.6 (virgin). The diminished NKC activity in pregnant mice was reflected in an increased mean number of virus particles in the peritoneal wash, 266 +/- 66 PFU/ml, compared to 38 +/- 11 PFU/ml in virgin mice (P less than 0.05). We concluded that NKC, but not ADCC, to HSV-infected targets was suppressed and that HSV elimination was impaired in pregnant mice.

Antibody-dependent cell-mediated cytotoxicity against IBR-infected bovine kidney cells by ruminant neutrophils: the role of lysosomal cationic protein

Antibody-dependent cell-mediated cytotoxicity (ADCC) of infectious bovine rhinotracheitis (IBR)-infected bovine kidney cells (MDBK) by neutrophils was demonstrated. Neutrophils from bovine and sheep mammary exudate and peripheral blood, and also from human peripheral blood, were all active in the presence of anti-IBR antibody. The component of the ruminant neutrophil granules which was responsible for cytotoxicity appeared to be cationic protein since purified cationic protein lysed the virus-infected cells and heparin inhibited cytotoxicity. Human neutrophil cytotoxicity to herpes simplex virus (HSV)-infected human Chang liver cells was also inhibited by heparin. Human neutrophil cytotoxicity to IBR-infected bovine kidney cells did not appear to be mediated by cationic protein since it was inhibited by the chelators of oxidative intermediates DMSO, thiourea, tryptophane, benzoate and mannitol, and not by heparin.

Antibody-dependent cellular cytotoxicity and natural killer cytotoxicity of peritoneal cells from nude mice to herpes simplex virus-infected cells

Nude BALB/c mice (athymic) were more susceptible to fatal herpes simplex virus (HSV) than normal BALB/c mice (P = 0.002). The peritoneal cells of nude mice mediated levels of antibody-dependent cellular cytotoxicity (ADCC) of equal or greater magnitude than cells from normal BALB/c, heterozygote nu/+, or C57BL/6 mice. Unstimulated natural killer cytotoxicity of peritoneal cells from nude mice was higher (P less than 0.05) than that mediated by cells from C57BL/6 mice. Nude mice failed to make anti-HSV ADCC antibody 6 to 14 days post HSV inoculation, at times when nu/+, BALB/c, and C57BL/6 mice produced antibody. Passive reconstitution of nude mice with high titer intraperitoneal anti-HSV immune globulin provided circulating anti-HSV ADCC antibody and significant protection against lethal HSV infection.

Lysis of herpesvirus-infected cells by macrophages activated with free or liposome-encapsulated lymphokine produced by a murine T cell hybridoma

Thioglycolate-induced mouse peritoneal macrophages were activated in vitro by the lymphokine designated macrophage-activating factor (MAF) produced by a murine T cell hybridoma to lyse herpes simplex virus type 2 (HSV-2)-infected murine target cells. Comparison of uninfected BALB/c 10E2 cells with HSV-2-infected 10E2 cells showed that macrophages activated with MAF selectively destroyed HSV-2-infected cells and left uninfected cells unharmed, as measured by an 18-h 51Cr-release assay. In contrast, macrophages treated with medium were as efficient as MAF-activated macrophages in suppressing the production of HSV-2 from virus-infected cells. These findings suggest that macrophages must attain an activated state to lyse HSV-2-infected cells. Finally, incubation of macrophages with liposomes containing MAF was shown to be a highly efficient method for activation of macrophages against HSV-2 infected cells. The ability to selectively destroy herpesvirus-infected cells in vitro by macrophages activated with liposome-encapsulated MAF suggests that the therapeutic efficacy of this treatment in vivo should be evaluated.