11 research outputs found

    Natural Cell-Mediated Cytotoxicity in Cutaneous T-Cell Lymphomas

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    Natural cell-mediated cytotoxicity was studied in 24 patients with cutaneous T-cell lymphomas and in 18 age- and sex-matched controls studied concomitantly. Percent cytotoxicity was determined by 4-h 51Cr release assay using K562 targets at effector to target ratios of 100:1, 50:1, and 25:1. Mean percent cytotoxicity was significantly lower in patients than in controls at an effector to target cell ratio of 100:1. Likewise, decreased cytotoxicity was found at effector to target ratios of 50:1 and 25:1, although this difference was not significant. When natural killer activity was analyzed separately for males and females, cytotoxicity was lower in both, although the decrease was significant only for male patients. Impairment of natural killer activity did not correlate with blood zinc levels, but appeared to correlate with stage of disease

    Efficacy of an adenovirus-vectored foot-and-mouth disease virus serotype A subunit vaccine in cattle using a direct contact transmission model

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    Abstract Background A direct contact transmission challenge model was used to simulate natural foot-and-mouth disease virus (FMDV) spread from FMDV A24/Cruzeiro/BRA/55 infected ‘seeder’ steers to naïve or vaccinated steers previously immunized with a replication-deficient human adenovirus-vectored FMDV A24/Cruzeiro/BRA/55 capsid-based subunit vaccine (AdtA24). In two independent vaccine efficacy trials, AdtA24 was administered once intramuscularly in the neck 7 days prior to contact with FMDV A24/Cruzeiro/BRA/55-infected seeder steers. Results In Efficacy Study 1, we evaluated three doses of AdtA24 to estimate the 50%/90% bovine protective dose (BPD50/90) for prevention of clinical FMD. In vaccinated, contact-challenged steers, the BPD50/90 was 3.1 × 1010 / 5.5 × 1010 AdtA24 particles formulated without adjuvant. In Efficacy Study 2, steers vaccinated with 5 × 1010 AdtA24 particles, exposed to FMDV A24/Cruzeiro/BRA/55-infected seeder steers, did not develop clinical FMD or transmit FMDV to other vaccinated or naïve, non-vaccinated steers. In contrast, naïve, non-vaccinated steers that were subsequently exposed to FMDV A24/Cruzeiro/BRA/55-infected seeder steers developed clinical FMD and transmitted FMDV by contact to additional naïve, non-vaccinated steers. The AdtA24 vaccine differentiated infected from vaccinated animals (DIVA) because no antibodies to FMDV nonstructural proteins were detected prior to FMDV exposure. Conclusions A single dose of the AdtA24 non-adjuvanted vaccine conferred protection against clinical FMD at 7 days post-vaccination following direct contact transmission from FMDV-infected, naïve, non-vaccinated steers. The AdtA24 vaccine was effective in preventing FMDV transmission from homologous challenged, contact-exposed, AdtA24-vaccinated, protected steers to co-mingled, susceptible steers, suggesting that the vaccine may be beneficial in reducing both the magnitude and duration of a FMDV outbreak in a commercial cattle production setting
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