M Sharon

Edema associated with improved glycemic control in an adolescent with type 1 diabetes.

5. Barnes GP, Bowles WF III, Carter HG. Acute necrotizing ulcerative gingivitis: a survey of 218 cases. J Periodontol 1973;44:35-42. 6. Jimenez ML, Ramos J, Garrington G, Baer PN. The familial occurrence of acute necrotizing gingivitis in children in Colombia, South America. J Periodontol 1969;40:414-6. 7. Kardachi B J, Clarke NG. Aetiology of acute necrotizing ulcerative gingivitis: a hypothetical explanation. J Periodontol 1974;45:830-2. 8. Pindborg J J, Bhat M, Devanath KR, Narayana HR, Ramachandra S. Occurrence of acute necrotizing gingivitis in South Indian children. J Periodontol 1966;7:14-7. 9. Moffet HL. Pediatric infectious diseases. Philadelphia: JB Lippincott, 1981:22. 10. Hirschfeld I. Vincents infection of the mouth: clinical incidents in its diagnosis and treatment. J Am Dent Assoc 1934;21:768-83. 11. Brucker M. Gingivitis and Vincents infection in children. J Dent Child 1956;23:116-34. 12. Heylings RT. Electron microscopy of acute ulcerative gingivitis (Vincents type). Br Dent J 1967;122:51-6.

The multisubunit interleukin-2 receptor

Interleukin-2 (IL-2) is a 15,500 dalton glycoprotein hormone of the immune system that was originally identified in 1976 as a T-cell growth factor-promoting activity.’ Subsequently, the factor was purified: molecularly cloned? and produced in large quantities. In the 14 years since its identification, a great deal of information has been generated about the IL-2/IL-2 receptor system. We will review the field, focusing principally on the evolving knowledge of the complexity of the structure of the IL-2 receptor.

Identification of a Novel Interleukin-2 Receptor Subunit

Interleukin-2 (IL2) binds to both high (Kd = 10–30 pM) and low (Kd = 10–30 nM) affinity IL2 receptors on activated T lymphocytes (1,2). Both classes of receptors share reactivity with anti-Tac monoclonal antibody and therefore contain the “Tac antigen” or 55 kD IL2 binding protein (3,4). The high affinity receptors account for approximately ten percent of the total number of receptors on activated T cells (2). It is generally believed that the high affinity receptors mediate the growth and differentiation effects of IL2, although the contribution, if any, of low affinity sites to such effects has not been as carefully examined. Only the high affinity sites undergo receptor mediated endocytosis after the binding of IL2 (5,6). The molecular basis for the distinction between the different classes of receptors has been unclear heretofore, and this short report will summarize the data from our laboratory, some of which has been published (7).