In 1979, Wahl et al published the following experiment (Infect. Immun. 23:8-13),
ID: 191607 • Letter: I
Question
In 1979, Wahl et al published the following experiment (Infect. Immun. 23:8-13), in which they further compared the effects of exposing peritoneal macrophages from C3H/HeJ mice vs control C3H/HeN mice to LPS 3f. The authors used peritoneal macrophages, as you also have in the laboratory. Why is this particular type of macrophage so widely used in immunological research? 3g. What kind of molecule is PGE2? (hint: what does PG stand for?) 0.1 1.0 10 100 LPS (g/mL) FIG. 1. Effect of varying concentrations of LPS on prostaglandirn production by macrophages from C3H/HeN and C3H/HeJ mice. Peritoneal macrophages were plated at 10 cells per 35-mm petri dish in 2 ml of medium. The culture media were harvested 48h after exposure to endotoxin and assayed for PGE2. The data represent the mean of two determinations from each of the duplicate cultures 3h. What are some effects of PGE2? The harvested culture media were acidified with 1 mL of 1 M sodium citrate (pH 3.5) and extracted in 30 mL of chloroform. The aqueous phase was removed by aspiration, and the chloroform was evaporated under a stream of air. Prostaglandin concentrations in the chloroform extract were determined either by radioimmunoassay utilizing specific antibodies to PGE (Miles Laboratory, Elkhart, Ind.). These immunoglobulins bind equally to PGEI, and PGE2. The results are presented as PGE2 equivalents, since this prostaglandin was utilized to derive the standard curve, and the data obtained are representative of several experiments. 3i. PGs are synthesized by cellular enzymes called COXI and COX2, and NSAID medicines inhibit these. What does NSAID stand for, and what are some examples of NSAID's? 3j. The methods section of the figure legend describes the use of immunoglobulins. What is the other common term for immunoglobulins, and what is their use in this experiment? 3k. What can be concluded from the data presented in this figure?Explanation / Answer
Ans 3f) The peritoneal macrophages are used in number of laboratory research. Such macrophages are used as it can be easily obtained from the mouse peritoneal cavity. It is mostly used in the study of immune response and related things as it exhibits different and distinct type of phenotypes along with functions and origins. It is also the most abundant subset that is found under steady state conditions.
Ans 3g) PGE2 is prostaglandin E2 B which is also known as dinoprostone and it is a type of prostaglandin that is naturally occurring. It has number of functions and mostly used during termination of pregnancy, keep off bleeding after delivery, labor induction etc. It belongs to the oxytoxics family and it binds to the prostaglandin E2 receptor that leads to dilation of the blood vessels.
Ans 3h) Effects of PGE2:-
Ans 3i) NSAIDs stands for Non-steroidal anti-inflammatory drugs. They are class of drugs which helps in reduction of pain, reduces fever, prevent clotting of blood and helps in reducing inflammation. They are responsible for inhibiting the activity of cyclooxygenase enzymes (COX-1 and COX-2). They mostly act as pain killers which help in reducing the pain. Some of the examples are aspirin, ibuprofen etc.
Ans 3j) The common term here used in immunoglobulins is macrophages. They are used here for binding to PGE1 and PGE2 and used for pursuing the results of the experiment.
Ans 3h) The graph shows us the effect of diverse concentration of LPS on prostaglandin production with help of macrophages. And two mice - C3H/HeN and C3H/HeJ, were used. In C3H/HeN, it was seen that the prostaglandin concentration increased with LPS and in case of C3H/HeJ, the prostaglandin concentration was stable and gradually declined and increased slightly again.