Literary Summary of “Effects of Antifungal Agents and γ Interferon on Macrophage Cytotoxicity for Fungi and Tumor Cells”.

The experimenters in this journal describe the influence of antifungal agents on acquisition of the activated state of the microphage. Stating that the macrophages modify their activity in response to the microbes in an infection. The experimenters continue to state that metabolic functions are factors that may affect the way the cells change their state of activation when testing the toxicity of the chemical substance on cultures. The experimenters noted a particular factor, calling it a marker that targets the neoplastic or microbial cells and kills them.

The experimenters discovered when using bacillus Calmette-Guerin (BCG); that the peritoneal cells when introduced with limited quantities of endotoxin become fully cytotoxic for susceptible tumor cell lines (Perfect, J. et al., 1987). The experimenters exclaim that it is this tumoricidal activity that is the designated marker for the activated macrophages. Continuing this line of thought the experimenters then state that the 1^st signal in this activation process is γ Interferon (IFN- γ) when testing the toxicity of the chemical substance on cultures for intracellular infection.

Experimenters posed that one hypothesis could be that the antimicrobial agents they were going to use may act against the invading fungi by promoting the host immune response. With that hypothesis; the question the authors were trying to answer in this journal is the study of the effector systems of activated murine macrophages against fungi (Perfect, J. et al., 1987). In this journal the experimenters state that they “will be working with three target cells. Murine fibro sarcoma cells (3T12); Cryptococcus neoformans H99/C3D, a clone from a human pathogenic isolate that does not increase capsule size in response to physiological concentrations of carbon dioxide [24]; and Candida parapsilosis, a nonpathogenic strain isolated from the laboratory environment (Perfect, J. et al., 1987)”.

The experimenters in this journal used various research items and obtained supplies from Wilmington Massachusetts, the Trudeau Institute in Saranac Lake New York, Detroit Michigan, Gibco in Grand Island New York, Corning New York, and Salt Lake City Utah. The experimenters performed the laboratory experiments at the Duke University Medical Center in Durham, North Carolina. Having all the various supplies and research items necessary to perform the experiment the experimenters conducted at least three different experiments for each additive. Periodically all the additives, medium and plastics were checked for endotoxin contamination by amebocyte lysate assay (Perfect, J. et al., 1987).

C. neoformans or C. parapsilosis (yeasts) were grown overnight and suspended in modified DMEM and adjustments were made by the hemocytometer and counts yielded 10³ yeast for a total volume of 0.2 mL per well. Macrophage, Fungistatic, and the antifungal agent assays were washed five times with DMEM before any yeasts were added. As a control, wells without cells were included for each additive. Wells were then cultured after being prepared on Sabouraud’s agar after lysing of host cells with a chemical compound of deoxycholate at 0.5% (Perfect, J. et al., 1987).

The experimenters did a one-way analysis of variance on each set of three of the experiments. The experimenters in case of finding a difference between grounds a multiple comparison analysis by Tukey’s method would be used. Visual results were good, having showed correlation with those found using the more quantitative thymidine release assay for tumoricidal activity (Perfect, J. et al., 1987).

According to the results, the macrophage activation for tumor killing appeared to work whereas the antifungal agents had no effect. The experimenters found the serum to be with in tolerance range for human therapeutic purposes. The experimenters explain that a significant cytosidal effect by the macrophages on the tumor cell growth was found and that the next step would be to determine whether macrophage activation for tumor cell cytotoxicity correlated with the ability to inhibit or kill fungal cells (Perfect, J. et al., 1987).

With previous knowledge and experience in macrophage activation, the experimenters knew that more consistent results could be obtained if the culture medium was to be left throughout the testing. With previous knowledge of this, endotoxin was used because the experimenters knew it would have no direct effect on antifungal activity. The experimenters determined in previous experiments that the azole compounds used had no prior effect. However, results showed dramatic effects on yeast growth.

The experimenters postulated that direct antifungal activity was due in part by human error in the preparation and cleansing phase. This meant that a drug must have remained in the macrophage cultures to give those results. Further testing showed active drug remains within the monolayers or the surfaces of the plastic culture vessel despite extensive washing (Perfect, J. et al., 1987). The experimenters removed the cells from the tissue culture container, washed and lysed in 0.5% deoxycholate again assuring no further contaminates. The process was repeated, after 24 hours desired results showed.

The experimenters were able to confirm that the activating effect of AMB in tumor cell killing by macrophages (Perfect, J. et al., 1987). The experimenters were able to show that the primed macrophage was made cytotoxic for tumor cells in the presence of therapeutic concentrations of AMB (Perfect, J. et al., 1987). Having acceptable results and demonstrating findings the experimenters had shown that fungicidal activity did stay within the cells even after having been removed from by an antifungal medium. Tests had shown that the compound was biologically active and attached to the cells. The experimenters explain that this may be useful in understanding macrophage-yeast interactions during antifungal treatment (Perfect, J. et al., 1987).

Reference Cited

Perfect, J., Granger, D., & Durack, D. (1987). Effects of Antifungal Agents and γ Interferon on Macrophage Cytotoxicity for Fungi and Tumor Cells. The Journal of Infectious Diseases, 156(2), 316-323. Retrieved from http://www.jstor.org/stable/30136160