Analysis of apoptosis of lymphoid cells in fish exposed to immunotoxic compounds

Abstract

Background Chemical induction of apoptosis in cells is believed to contribute to toxicity. Techniques for measuring apoptosis have increased in both sensitivity and number and in many cases can be readily extended to nontraditional research species. A comparison of established assays for measuring apoptosis of lymphoid cells has thus far not been performed in the fish and thus would be efficacious in assessing immunotoxicity. Methods The present study evaluated chemical‐induced immune cell apoptosis in fish (tilapia, Oreochromis niloticus) exposed to two known immunotoxic chemicals, azathioprine and T‐2 toxin. Cytocentrifugation and light microscopy of leukocyte‐enriched cell samples from the pronephros (i.e., the fish primary hematopoietic compartment) demonstrated chemical‐related increases in apoptotic bodies. This observation was examined further with the ApoAlert™ Annexin V Apoptosis kit and two DNA‐binding dyes employed for detecting apoptosis, 7‐aminoactinomycin D (7‐AAD) and propidium iodide (PI). Results The apoptotic probes confirmed the microscopic observations of increased apoptosis in the chemical‐exposed fish. The ApoAlert™ annexin V and 7‐AAD assays, which discriminate early and late apoptosis/necrosis, compared well in identifying apoptotic populations. PI staining in Vindelov's solution was unable to detect early apoptosis. Conclusions The present data suggest that apoptotic immune cells may be a useful marker for certain immunotoxicant exposures in fish. These findings agree with those of previous reports that fish may respond immunologically in a manner similar to mammals after immunotoxicant challenge. Cytometry 39:310–318, 2000 © 2000 Wiley‐Liss, Inc.

Suppressive effect of elongation factor 2 on apoptosis induced by HIV-1 viral protein R

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Anti-Vpr Activities of Heat Shock Protein 27

“…Annexin V-positive cells typically represent early ( Figure 3B, bottom right quadrant) and late ( Figure 3B, upper right quadrant) apoptotic cells (30). As shown in Figure 3B, un-induced cells showed background level of apoptosis ranging from 0.20% to 0.32% for early apoptosis and from 0.74% to 2.46% for late apoptosis.…”

Horses Experimentally Infected with Sarcocystis neurona Develop Altered Immune Responses In Vitro

“…Five or 10,000 cells per gated sample were collected by the flow cytometer. Based on the intensity of staining, cells were classified by their subset and as either 7AAD dull (live cells), 7AAD moderate (early apoptosis), or 7AAD bright (late apoptosis) (Gogal et al, 2000;Yang et al, 2006).…”