X-linked severe combined immunodeficiency (X-SCID) leads to a TKeywords: Atypical SCID r Common gamma chain r Cytokine signaling r Leaky SCID r Severe combined immunodeficiencyAdditional supporting information may be found in the online version of this article at the publisher's web-site

Polymorphonuclear leukocytes, when properly stimulated in vitro (1, 2), release an endogenous pyrogen that is believed to play a central role in the pathogenesis of fever (3,4). Demonstration that the release process is proroundly affected by factors involving electrolyte transport (2, 5) has suggested that the pyrogen may be derived from the membranes of the stimulated ceils (s).Previous studies on the nature of rabbit leukocytic pyrogen (6, 7) have revealed that it is: (a) nondialyzable, (b) relatively heat-labile, (c) precipitable with perchloric acid (HC104), (d) destroyed by phenol, (e) solublein 50 % methanol and 33 % saturated ammonium sulfate, (f) unaffected by butanol treatment, (g) inactivated by both diisopropyl fluorophosphate (DFP) and dinitrofluorobenzene (DNFB), and (h) rendered inert by trypsin and pepsin. These properties collectively indicate that it contains an essential protein.Approximately 50-fold purification of the crude pyrogen was first achieved by butanol treatment, removal of extraneous protein by methanol precipitation and anionic exchange chromatography (DEAE), and precipitation with ttCI04 (6). A later modification of the procedure (8) led to a further 4-fold purification and separated the activity of the pyrogen from that of lysozyme, an enzyme known to be released under the same conditions from polymorphonuclear leukocytes (2).Better methods of obtaining and purifying the pyrogen have since been devised, and further studies on its chemistry have been undertaken.

Previous studies on the release of endogenous pyrogen from rabbit exudate granulocytes in vitro (1) have revealed: (a) that large amounts of pyrogen are released when the cells are incubated (37°C) in 0.15 M NaC1; (b) that the release is blocked if physiological concentrations of K + are added to the medium; and (c) that inhibition by ouabain of K + transport into the cells nullifies the blocking effect of K + on the release process. These results indicate that deprivation of K ions causes exudate granulocytes to release endogenous pyrogen. Other cellular proteins (e.g., aldolase) are also released with the pyrogen (1). Furthermore, it has been found that sulfhydryl reagents, such as iodoacetate, p-chloromercuribenzoate, and N-ethylmaleimide, which inhibit the energyrequiring N a -K transport system of the cells (2), also inhibit the release process (3). The present studies were undertaken to investigate further the mechanism whereby K + deprivation stimulates exudate granulocytes to release pyrogen. Material and MethodsThe methods used to exclude extraneous pyrogens, to obtain exudate granulocytes from rabbits, and to assay granulocytic pyrogen, have been described elsewhere (4, 5).Plasma was separated from rabbit blood after the addition of heparin (10 IU per ml of Liquaemin, Organon, Inc., West Orange, N. J.). Endotoxin from Escherlchla coli 0111:B4 was purchased from Difco Laboratories, Detroit, Mich.; inulin from Mann Research Laboratories, Inc., New York, N.Y.; and puromycin dihydrochloride from Nutritional Biochemicals Corp,, Cleveland, Ohio; modified Hanks' solution (MH) was prepared as described in reference (6).