Tuftsin: a naturally occurring immunopotentiating factor. I. In vitro enhancement of murine natural cell-mediated cytotoxicity

Tuftsin is a physiologic tetrapeptide, which has recently been shown to possess immunoadjuvant properties including the stimulation of macrophage and granulocyte phagocytosis, migration, bactericidal, and tumoricidal activities. Tuftsin has also been reported to possess in vivo immunologically mediated anti-tumor potential. To determine the potential role of tuftsin as an antineoplastic immunoadjuvant, the in vitro effects of tuftsin on murine natural cell-mediated cytotoxicity were studied. We observed that in vitro treatment of mouse splenic effector cells with synthetic tuftsin induced a pronounced enhancement of natural killer cell (NKC) cytotoxicity against the T cell lymphoma Yac-1. The magnitude of NKC enhancement was directly dependent upon the concentration of tuftsin employed, with maximum NKC stimulation observed at tuftsin concentrations of 50 to 100 microgram/ml. The tuftsin induced enhancement of NKC activity was not strain specific, since equivalent stimulation was seen in CBA/J, C56BL/10, and DBA/2 mice. Elimination of macrophages, monocytes, T cells, and immunoglobulin-bearing cells had no effect on the dose-dependent tuftsin stimulation of natural cell-mediated cytotoxicity; thus the characteristics of the effector cells activated by tuftsin were consistent with those reported for NKC. We also observed that treatment of splenic effector cells with tuftsin prolonged the cytotoxic capabilities of these cells beyond 18 hr.     

Intracellular polyamine biosynthesis is required for interleukin 2 responsiveness during lymphocyte mitogenesis

The objective of the present investigation was to define a more precise role for intracellular polyamine biosynthesis with respect to specific inducible events which regulate lymphocyte mitogenesis. In this regard, we have examined the effect of polyamine depletion on interleukin 2 (IL-2) production, receptor expression, and responsiveness in Con A stimulated mononuclear leukocytes (MNL). Polyamine depletion was achieved utilizing the specific irreversible inhibitor of ornithine decarboxylase (ODC), DL-alpha-difluoromethylornithine (DFMO). Polyamine depletion of MNL augmented detectable levels of Con A-induced IL-2 activity. In contrast, the ability of polyamine depleted MNL to respond to saturating levels of IL-2 (100 U/ml) following 72 or 96 hr of Con A stimulation was reduced 100 and 81%, respectively. Nonetheless, polyamine depletion did not impair the induction of IL-2 receptor expression. High-affinity IL-2 receptor density in the polyamine depleted population was greater than control cells late in culture (96 hr). The expression of high-affinity IL-2 receptors did not correlate with an ability to respond to IL-2 in the polyamine depleted population. The results of this study demonstrate for the first time that intracellular polyamine biosynthesis is required for IL-2 responsiveness during a primary mitogenic lymphocyte response.     

Examination and characterization of distribution system biofilms

Investigations concerning the role of distribution system biofilms on water quality were conducted at a drinking water utility in New Jersey. The utility experienced long-term bacteriological problems in the distribution system, while treatment plant effluents were uniformly negative for coliform bacteria. Results of a monitoring program showed increased coliform levels as the water moved from the treatment plant through the distribution system. Increased coliform densities could not be accounted for by growth of the cells in the water column alone. Identification of coliform bacteria showed that species diversity increased as water flowed through the study area. All materials in the distribution system had high densities of heterotrophic plate count bacteria, while high levels of coliforms were detected only in iron tubercles. Coliform bacteria with the same biochemical profile were found both in distribution system biofilms and in the water column. Assimilable organic carbon determinations showed that carbon levels declined as water flowed through the study area. Maintenance of a 1.0-mg/liter free chlorine residual was insufficient to control coliform occurrences. Flushing and pigging the study area was not an effective control for coliform occurrences in that section. Because coliform bacteria growing in distribution system biofilms may mask the presence of indicator organisms resulting from a true breakdown of treatment barriers, the report recommends that efforts continue to find methods to control growth of coliform bacteria in pipeline biofilms.     

Expression and purification of recombinant cynomolgus monkey cholesteryl ester transfer protein from Chinese hamster ovary cells

Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesteryl ester from high- and low-density lipoproteins to triglyceride-rich lipoproteins, and reciprocally mediates triglyceride transfer. The gene for cynomolgus monkey CETP was expressed in serum-free CHO culture with 2g/ml insulin as its only exogenous protein supplement. Cell growth was facilitated by immobilizing the CHO cells in alginate beads. Recombinant CETP (rCETP) was purified 176-fold with a three-step protocol resulting in a 60% final yield as measured by a fluorescent CETP activity assay. Typically, 3.4 mg of rCETP was purified from 1700 ml of media by affinity-gel chromatography involving Reactive Red 120 (RR120) followed by concanavalin A Sepharose 4B and rechromatography on RR120. SDS-PAGE shows a single broad band ofM _r , ranging from 68,000 to 74,000 which immunoreacts in Western blot analysis. Amino acid analysis and protein sequencing of the purified protein agree with the theoretical amino acid composition and sequence of cynomolgus CETP.     

Construction of disease-specific cytokine profiles by associating disease genes with immune responses

The pathogenesis of many inflammatory diseases is a coordinated process involving metabolic dysfunctions and immune response—usually modulated by the production of cytokines and associated inflammatory molecules. In this work, we seek to understand how genes involved in pathogenesis which are often not associated with the immune system in an obvious way communicate with the immune system. We have embedded a network of human protein-protein interactions (PPI) from the STRING database with 14,707 human genes using feature learning that captures high confidence edges. We have found that our predicted Association Scores derived from the features extracted from STRING’s high confidence edges are useful for predicting novel connections between genes, thus enabling the construction of a full map of predicted associations for all possible pairs between 14,707 human genes. In particular, we analyzed the pattern of associations for 126 cytokines and found that the six patterns of cytokine interaction with human genes are consistent with their functional classifications. To define the disease-specific roles of cytokines we have collected gene sets for 11,944 diseases from DisGeNET. We used these gene sets to predict disease-specific gene associations with cytokines by calculating the normalized average Association Scores between disease-associated gene sets and the 126 cytokines; this creates a unique profile of inflammatory genes (both known and predicted) for each disease. We validated our predicted cytokine associations by comparing them to known associations for 171 diseases. The predicted cytokine profiles correlate (p-value<0.0003) with the known ones in 95 diseases. We further characterized the profiles of each disease by calculating an “Inflammation Score” that summarizes different modes of immune responses. Finally, by analyzing subnetworks formed between disease-specific pathogenesis genes, hormones, receptors, and cytokines, we identified the key genes responsible for interactions between pathogenesis and inflammatory responses. These genes and the corresponding cytokines used by different immune disorders suggest unique targets for drug discovery.     

THE LANGUAGE-HANDICAPPED CHILD—Coordinated Evaluation by Physicians and Educators

Seventy children were studied during 1959 in a special school program because of major language problems. A team of medical and educational personnel studied each child during a ten-day school enrollment. The results of the medical and educational studies were of great value in establishing the correct diagnosis and devising a suitable educational program for the children.     

Variation in Composition of Yeast Phosphohexosans

Omitting of KH(2)PO(4) from culture media leads to the production of altered phosphohexosans or neutral extracellular mannans by yeasts that otherwise elaborate phosphogalactans and phosphomannans.