Bacteria chemical agents targeting

In 1961 it was reported that human leukocytes were capable of producing IFN in response to viral infections [8,9]. This viral stimulation of white blood cells was initially used to produce leukocyte IFN for clinical applications. Identification of a number of varied IFN inducers such as mycoplasma or other microorganisms in cell cultures, lipopolysaccharides (LPS, derived from bacteria membranes), tumor-derived or virus-transformed cells, and synthetic chemical compounds such as polyanions and poly I C (poly inosine-cytosine) suggested that different IFN mixtures could be derived from interaction of various inducing agents and appropriate target cells [10-16]. Another pH-labile, nonvirus-induced IFN termed immune-IFN (induced by immune effector cells) was discovered in 1965. It was produced by... 

Chemicals are also used to select between different biological systems and these include agents that selectively kill one of the organisms. Common examples are the antibiotics. The antibiotics that are most useful in medicine are those that target enzymes not found in the human. An example is penicillin (Figure 8). This antibiotic resembles a substrate used for the synthesis of the cell wall of many bacteria. Penicillin will bind to the enzyme and subsequent events will inactivate the enzyme permanently. In other words, penicillin not only binds to the active sites of the bacterial enzyme, but modifies that enzyme in a manner that makes it permanently inactive. Since humans do not make cell wall, there are no enzymes of this type to be influenced and penicillin should have little effect on human enzymes. This very selective manner of killing is extremely valuable in medicine. Obviously, since the antibiotics we use are isolated from other organisms, this approach was actually developed by other life forms. 

---