Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the bodys natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells. IL-2 receptor
IL-2 is a member of a cytokine family, each member of which has a four alpha helix bundle; the family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through the IL-2 receptor, a complex consisting of three chains, termed alpha (CD25), beta (CD122) and gamma (CD132). The gamma chain is shared by all family members.The IL-2 receptor (IL-2R) α subunit binds IL-2 with low affinity (Kd~ 10−8 M). Interaction of IL-2 and CD25 alone does not lead to signal transduction due to its short intracellular chain but has the ability (when bound to the β and γ subunit) to increase the IL-2R affinity 100-fold. Heterodimerization of the β and γ subunits of IL-2R is essential for signalling in T cells. IL-2 can signalize either via intermediate-affinity dimeric CD122/CD132 IL-2R (Kd~ 10−9 M) or high-affinity trimeric CD25/CD122/CD132 IL-2R (Kd~ 10−11 M). Dimeric IL-2R is expressed by memory CD8+ T cells and NK cells, whereas regulatory T cells and activated T cells express high levels of trimeric IL-2R.
Misoprostol alone may be more effective in earlier gestation. WHO guidelines recommend for pregnancies up to 12 weeks to use 12 tablets of 200 mcg (micrograms). The woman should put 4 tablets of misoprostol under the tongue or far up the vagina and let them dissolve for 30 minutes. The woman should wait 3 hours and repeat with 4 pills under the tongue or in the vagina for 30 minutes. She should wait 3 hours and repeat once more. It works in 90% after first attempt and, in case of failure, the attempt may be repeated after a minimum of 3 days.Misoprostol can also be used to dilate the cervix in preparation for a surgical abortion, particularly in the second trimester (either alone or in combination with laminaria stents). Vaginal misoprostol can also be used to facilitate intrauterine device insertion after previous insertion failure.Misoprostol by mouth is the least effective treatment for producing complete abortion in a period of 24 hours due to the livers first-pass effect which reduces the bioavailability of the misoprostol. Vaginal and sublingual routes result in greater efficacy and extended duration of action because these routes of administration allow the drug to be directly absorbed into circulation by bypassing the liver first-pass effect.Hematocrit or Hb tests and Rh testing are recommended before use for abortion confirmation of pregnancy. Following use, it is recommended that people attend a follow-up visit 2 weeks after treatment.