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From www.bloodjournal.org by guest on August 11, 2017. For personal use only. Double-Stranded RNA Induces Sickle Erythrocyte Adherence to Endothelium: A Potential Role for Viral Infection in Vaso-Occlusive Pain Episodes in Sickle Cell Anemia By Paula A. Smolinski, Margaret K. Offermann, James R. Eckman, and Timothy M. Wick Vaso-occlusive pain episodes in sickle cell anemia are hypothesizedt o be precipitated by adherence of sickle erythrocytes t o vascular endothelium in the microcirculation. Febrile episodes, thought t o be viral in etiology, are frequently associated with vaso-occlusion; however, a direct link between viral infection and vascular occlusion has not yet been established. Many pathogenic viruses contain doublestranded RNA or replicate through double-stranded RNA intermediates. Double-stranded RNA has beenshown to induce vascularcell adhesion molecule-l (VCAM-1)protein expression on endothelial cells. Recently,a new adhesionpathway hasbeendescribed between VCAM-1expressed on cytokine stimulated endothelium and the a.& integrin complex expressed on sickle reticulocytes.Based on these observations, the hypothesis was developed that viral infection, through double-stranded RNA intermediates, increases endothelial VCAM-1expression leading t o sickle erythro- cyte adhesiont o endothelium via an a&-VCAM-l "dependent mechanism. In support of this hypothesis, endothelial cells exposedt o the synthetic double-stranded RNA poly(l:C) or the RNA virus parainfluenza 1 (Sendai virus) express increased levels of VCAM-1 andsupport increased sickleerythrocyte adherence under continuous flow at 1.0 dynelcm' shear stress as compared with unstimulated endothelium. Blocking antibodies directed against either VCAM-l on the endothelium or a& on sickle erythrocytes inhibit nearly all of the increased sickle cell adherence caused by poly(l:CI or Sendai virus. These results support the hypothesis that viruses, through double-stranded RNA elements, caninduce sickle erythrocyte adherence t o endothelium through a&VCAM-l-mediated adhesion and provide a potential link between viral infection and microvascular occlusion precipitating sickle cell pain episodes. 0 1995 by The American Societyof Hematology. S in endothelial cells independent of cytokine Based on these observations, we hypothesized that exposure of endothelial cells to synthetic double-stranded RNA or to parainfluenza 1 virus leads to increased sickle erythrocyte adherence via a4PI-VCAM-1 -mediated interactions. These studies, coupled with previous observations supporting the role of endothelial adherence in initiating vaso-occlusion, provide a mechanism by which certain viruses could induce pain episodes by initiating endothelial VCAM- 1 protein expression and promoting adherence of a,P,-positive sickle erythrocytes. ICKLE CELL ANEMIA is characterized by episodic periods of painful microvascular occlusion with tissue necrosis. Vaso-occlusion is hypothesized to occur when sickle erythrocyte transit through the microcirculation is delayed such that hemoglobin polymerization and erythrocyte sickling occur in the microcirculation and cause occlu~ i o n . "Adherence ~ of sickle erythrocytes to microvascular endothelium is posited as a major determinant of intracapillary transit time and a modulator of vaso-occlusive complications!-6 In recent years, specific adhesion pathways between both microvascular and large vein endothelium and sickle erythrocytes have been elucidated in a number of independent studies?"' Recent studies from our laboratory show that up to 25% of sickle reticulocytes express the a4PIintegrin complex and bind to vascular cell adhesion molecule-l (VCAM-1) expressed by cytokine activated endothelium." Because reticulocyte counts are elevated in sickle blood in response to shortened erythrocyte survival, this observation suggests that VCAM-1 expression induced by proinflammatory factors in vivo may cause significant adhesion of sickle erythrocytes to endothelium during immune activation. Pain episodes are often associated with febrile events precipitated by viral or bacterial infection." Many different cell types, including endothelial, have the capacity to recognize and respond to double-stranded FWA.I3-l5Pathogenic viruses with a double-stranded RNA genome or which replicate through double-stranded RNA intermediates, including parainfluenza 1 virus, Coxsackie virus, flavivirus, rhinovirus, and influenza virus, may directly induce proinflammatory cellular responses.'6 In animal studies, synthetic double-stranded RNA such as poly(1:C) induces many of the same pathogenic responses, as do intact viruses, including the development of a proinflammatory ~tate.'"'~ Among the genes induced by double-stranded RNA are class I interferons (a and @),l5 interleukin-6 (IL-6),l3 and IL-1." Recent studies show that double-stranded RNA also induces cellular adhesion molecules, including VCAM-l, Blood, Vol 85, No 10 (May 15). 1995: pp 2945-2950 MATERIALS AND METHODS Endothelial cell culture. Human umbilical vein endothelial cells (HUVECs) were harvested from umbilical cords by collagenase digestion" and grown to confluence in 0.1% gelatin-coated T-flasks in primary medium consisting of M199 (Sigma Chemical CO, St Louis, MO) with 20% heat-inactivated fetal calf serum (FCS; Intergen, Purchase, NY), 2 mmol/L L-glutamine (Sigma), and 100 U/ mL penicillin, 1 0 0 pg/rnL streptomycin, and 0.25 pg/mL amphotericin B (GIBCO Laboratories, Grand Island, NY). Confluent endothe- From the School of Chemical Engineering, Georgia Institute of Technology, Atlanta; the Division of Hematology/Oncology, Department of Medicine, Winship Cancer Center, Atlanta;and the Georgia Comprehensive Sickle Cell Center, Emory University School of Medicine, Atlanta, GA. Submitted April 15, 1994; accepted December 28, 1994. Supported in part b.y Grants No. HL-44960 and HL-48482 from the Heart, Lung, and Blood Institute ofthe National Institutes of Health Address reprint requests to Timothy M . Wick, PhD,Associate Professor, School of Chemical Engineering, Georgia Institute of Technology, 778 Atlantic Dr, Atlanta, GA 30332-0100. The publication costsof this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. section 1734 solely to indicate this fact. 0 1995 by The American Society of Hematology. 0006~4971/95/8510-0033$3.00/0 2945 From www.bloodjournal.org by guest on August 11, 2017. For personal use only. 2946 SMOLlNSKl ET AL lial monolayers were trypsinized using 0.001% trypsin-EDTA Cell Wells plate (Corning Glass Works, Corning, N Y ) i n passage (GIBCO)andsplit 1:3. Endothelialcells of passagetwo to four medium. After reaching confluence, each well was incubated for 20 were grown to confluence in individual Nunc Permanox Lab Tek hours with 200 pL control medium or medium supplemented with (Naperville, [L) wells coated with 0.1% gelatin. Passaged endothelial either IO0 pg/mL poly(I:C), 100 pg/mL poly(I), o r S00 U/mL TNFcells were culturedin passage medium consistingof primary medium LY or infectedwithparainfluenza I virus as describedabove.The supplemented with 100 pg/mL heparin (Sigma) and 25 pg/mL endo- remainder of the ELISA analysis was performed as previously dethelial cell growth factor(ECGF Boehringer Mannheim, Indianaposcribed." Endothelial VCAM-I protein expression was read on an lis, IN). ELISABio-TekMicroplateReader(Winooski,VT)at450nm. Background values were subtracted and all measurements were perErythrocyte suspensions. Wholebloodsampleswereobtained formed in quadruplicate and reported as mean values. by venipuncture into sodium citrate ( l :9 vol/vol) or sodium heparin (14.3 USP Units/mL) Vacutainer tubes (Becton Dickinson, RutherAdhesion assuys. The flow assay was performed using a parallel plate flow chamber at 37"C, as previously described." The treated ford, NJ) from normal donors or asymptomatic homozygous sickle endothelial monolayer was exposed to continuous flow at I dyne/ patients at the Georgia Comprehensive Sickle Cell Center at Grady cm' consisting of an initial 5-minute serum-free medium rinse, folMemorial Hospital (Atlanta, CA). Informed consent was obtained lowed by a 10-minute perfusion with 1 % hematocrit sickle cells in from all participants, and protocols were approved by the Human Investigations Committees of Emory University School serum-freemedium,andconcluding with a20-minuteserum-free of Medicine, medium rinse to remove nonadherent cells. The endothelial monoGeorgia Institute of Technology, and Grady Memorial Hospital. Patients showed no signs of pregnancy, obvious infection, thromboen- layer was then scanned at 20 X magnification, and adherent erythrobolic disease, or liver disease and werenot receiving anticoagulation cytesper field werecountedfor 20 randomfields.These values as adherenterythrocytes per square were averagedandreported therapy. Within 4 hours, the whole blood was centrifuged at l00g millimeter. for 10 minutes at 25°C and used in the experimental protocol within 24 hours. The erythrocyte-rich fraction was washed as previously Datu unalysis und .statistical met1zod.c.. Eachexperimentconsisted of aseriesofadherencemeasurementsusingendothelium described" and suspended to 1% hematocrit in serum-free medium from the same harvest and erythrocytes from the same patient (eg. I3 I (GIBCO)plus consistingofendothelialbasalmediaMCDB Fig l ) . For eachexperiment,theaveragenormalizederythrocyte 0.292 mg/mLL-glutamine(Sigma),0.227mg/mLcyclicAMP adherence obtained from counting the 20 microscopic fields is treated (Sigma), 0.1 mg/mLstreptomycin,neomycin,andamphotericin as a single observation. Each experiment was repeated several times (GIBCO), 0.001 mg/mL hydrocortisone (Sigma), 0.01 pg/mL epiusing sickle cells from different patients and grouped data for the dermalgrowthfactor(Clonetics,SanDiego,CA),0.2%(wt/vol) experiments are reported as mean -t standard error of mean. Percent human albumin (Sigma), 5.0 pg/mLhuman transferrin (Sigma), and blocking was calculated using the following equation: ([poly(I:C)5.0 pg/mL bovine insulin (Sigma). mediated adhesion] - [poly(l:C)-mediated adhesion with specified Endothelial and erythrocyte treatments. In preparation for flow antibody present])/([poly(I:C)-mediated adhesion] [basaladheassays, confluent endothelial cell monolayers were preincubated for sion]) X 100, andthecalculatedvaluesareindicatedabovethe 20 hours before flow with either control medium or control medium bars. Paired Student's t-tests were used to determine the statistical supplemented with either 500 U/mL tumor necrosis factor-a (TNFsignificance of differences." a;generously supplied by Dr Robert Swerlick, Emory University 100 pg/mLpolyinosinicacid: SchoolofMedicine,Atlanta,CA), polycytidilicacid[poly(I:C);PharmaciaLKBBiotechnologyInc, RESULTS Piscataway, NJ], 100 pg/mL polyinosinic acid [poly(I); Pharmacia], Effects of poly(I:C) on erythrocyte adherence. Toexor 100 pg/mL polycytidilic acid [poly(C); Pharmacia]. Control meplore the possible involvement of viruses through doubledium consisted of serum-free medium supplemented with 30% (voU stranded RNA intermediates in sickle cell vaso-occlusion, vol) human AB serum (GIBCO). A solution of 20 p L parainfluenza the adherence of sickle erythrocytes to poly(1:C)-stimulated I virus (Sendai virus; 10,000 HAU/mL; Spafas, Stoors, CN) per 3 mL M199 (Sigma) wasused when infecting endothelial cells. Where endothelial cells was compared with the adherence to unindicated,thevirussolutionwasaddedtoawashedendothelial stimulated endothelium. Sickle erythrocyte adherence was monolayerfor 1 hour of incubation.The virus solution was then increased more than fourfold when endothelial cells were removed, the monolayer was washed, and complete passage medium stimulated with poly(1:C). In contrast, normal erythrocyte was replaced. The endothelial cells were then used in a flow assay adherence did not increase when endothelial cells were stimor enzyme-linked immunosorbent assay (ELISA)20 hours postinfeculated with poly(1:C) (Fig 1). The level of sickle erythrocyte tion. adherence to poly(1:C)-stimulated endothelial cells was simiMonoclonal antibodies (MoAbs) were used in adhesion blocking l a r to that induced by the potent endothelial activator TNFexperiments. To block endothelial receptors, cells were incubated a (Fig 2). There was no increase in sickle erythrocyte adherwith 10 pg/mL anti-VCAM-I clone 1 G1 1 (AMAC Inc, Westbrook, ence to endothelial cells stimulated with the single-stranded ME) or 10 or 50 pg/mL anti-ICAM clone 84H10 (AMAC)" for I RNA molecules poly(1) (Fig 2) or poly(C) (data not shown), hour between the 20 hours of stimulation and the flow assay. To blockerythrocytereceptors, washed 1% erythrocytesuspensions indicating the specificity of poly(1:C)-induced sickle erythrowere centrifuged and the erythrocyte pellet was incubated with 10 cyte adherence. or 50 pg erythrocyte MoAbs, anti-a, clone HP2/1 (AMAC), antiPnly(I:C)-induced adherence is via a&,--VCAM-I interDl clone MoAbl3* (Collaborative Biomedicals, Bedford, MA), or actions. The increased sickle erythrocyte adherence was anti-glycophorinAcloneD2.10(AMAC)for 15 minutes."After associated with increased endothelial VCAM-l protein exincubation with the MoAbs, erythrocytes were suspended in serumpression (Fig 2, inset), suggesting that VCAM-I is involved free medium, centrifuged to remove unbound antibody, and resusin the observed adherence. MoAb blocking assays were perpended in fresh serum-free medium to I % hematocrit formed to further elucidate the mechanism of poly(1:C)-inMeasuring cell adhesion molecule protein expression. VCAM- I protein expression was quantified using an ELISA. Briefly, HUVECs duced sickle erythrocyte adherence. Poly(1:C)-mediated sickle erythrocyte adherence was blocked 98%by preincubawere grown to confluence in a 0.1% gelatin-coated 96-well Corning ~ From www.bloodjournal.org by guest on August 11, 2017. For personal use only. SICKLECELLADHERENCE 2941 ENHANCED BY VIRUS L Unstimulated Poly(l:C) stimulated v) 0 Fig 1. Sickle erythrocytes adhere t o poly(l:C)-stimulated endothelial cells. Erythrocyte adherence t o unstimulated or poly(l:C)-stimulated endothelium was quantified under continuous flowat 1 dynelcm2. Sickle erythrocyte adherence t o polyll:C)-stimulated endothelium was significantly greater than adherence t o unstimulated endothelium ( P < .0005, n = 11). Data are reported as mean 2 standard error for five normal donors and 11 asymptomatic sickle patients. l 100 tion of poly(1:C)-stimulated endothelial cells with antiVCAM-I antibody (Fig 3). Similarly, preincubation of sickle erythrocytes with anti-a4 antibody inhibited 80% of the observed sickle cell adhesion (Fig 3).In addition, preincubation of sickle erythrocytes with an anti-Dl antibody blocked 68% of poly(1:C)-induced adhesion (data not shown), further demonstrating the involvement of a4PI. To exclude nonspecific antibody interactions as a cause of the observed inhibition, the blocking abilities of antibodies against adhesion molecules not believed to be involved in sickle cell adhesion were determined. Preincu- bation of endothelialcells with 10 pglmL endothelial anti-ICAM-l antibody did not inhibit poly(1:C)-mediated adhesion (37.8 t 10.1 17 32.2 -t 9. I cellslmm’. n = 4). Preincubation of sickle erythrocytes with 10 pg anti-glycophorin A antibody also did not inhibit poly(1:C)-induced adhesion (37.8 2 10.1 v 35.8 2 11.8 cellslmm’, n = 4). Increasing the control antibody levels to S0 pg still did not initiate blocking (data not shown). These studies illustrate that poly(1:C)-induced sickle erythrocyte adherence occurs through interactions between erythrocyte a4Dl and endothelial VCAM- I . 70 60 50 - - -- -- 20 - --1--- 10 - -1 40 30 ... . \~\~\~\~.~\‘\’\~\~\~.‘.’ ............ T \’\’\’\’\‘\, \ 0 Unstimulated TNFa Poly(l:C) HUVEC Treatment pOlY(l) Fig 2. Sickle erythrocyte adherence levels parallel endothelial VCAM-1 expression. Sickle erythrocyte adherence t o unstimulated endothelial cells or endothelial cells stimulated with either 500 UlmL TNFa, l00 p g l mL poly(l:C), or 100 p g l m L polyll) was quantified under continuous flow at1 dynelcm2.Data are reported as mean ? standard error for five asymptomatic sickle patients [except n = 4 for poly (l)]. (Inset1 Endothelial VCAM-1 expression was quantifiedusing ELlSA forunstimulated endothelial cells or endothelia1 cells treated for 20 hours with the indicatedagonist. Data are reported as average OD reading for four identical wells and represent one data set. From www.bloodjournal.org by guest on August 11, 2017. For personal use only. SMOLlNSKl ET AL 2948 Fig 3. Poly(l:C)-induced sickle erythrocyte adherence occurs via ancx&,-VCAM-l -mediated mechanism. Sickle erythrocyte adherence t o endothelial cells stimulatedfor 20 hours with 100 pg/mL poly(l:C) was quantified under continuous flow of 1 dyne/cm2. Either 50 p g anti-cr4 antibody on sickle erythrocytes ( P c ,021 or 10 pg/mL anti-VCAM-l antibody on endothelium ( P < .02) inhibited poly(l:C)-induced sickle cell adherence. Data are reported as mean 2 standard error for four asymptomatic sickle patients. Enthrocyte adherence to endothelirml ir!fected w i t h pnroir!fllcen:a I virus. To determine whether an intactvirus would lead to similar increases in adherence as that observed with synthetic double-stranded RNA, endothelial cells were incubated with parainfluenza I virus (Sendai virus). The increased level of sickle erythrocyte adherence was comparable to that observed with poly(1:C)(Fig 4).and parainfluenza 1 led to increased levels of endothelial VCAM-I protein Fig 4. Adherence of sickle erythrocytes t o endothelial cells infected with parainfluenza 1 virus (Sendai virus) occurs via an cr&-VCAM-l-mediated mechanism. Sickle erythrocyte adherence t o endothelial cells infected with parainfluenza 1 virus (Sendai virus) was quantified under continuous flow at 1 dyne/cm2 as described. Where indicated, erythrocytes were incubated with 50 p g anti-cr, antibody or endothelial cells were incubatedwith 10 pg/mLanti-VCAM-lantibody. Data are reported as mean 2 standard error for five asymptomatic sickle patients (except n = 4 for antibody blocking). (Inset) Endothelial VCAM-1 expression was quantified usingELISA for unstimulated endothelial cells or endothelialcells treated for20 hours withthe indicated agonist. Data are reported as average OD reading for four identical wellsand represent one data set. 10 l5 5 0 expression (Fig 4, inset). Blocking antibodies directed against endothelial VCAM- 1 inhibited the virus-induced adhesion by 92% (Fig 4).Similarly, anti-a, or anti-P, antibodies on sickle erythrocytes reduced the adhesion by 63% (Fig 4)and 45% (data not shown), respectively. In addition, neither anti-ICAM-I (50 pg/mL) nor anti-glycophorin A (S0 pg) blocked the virus-induced adherence (data not shown). These data suggest that live RNA virus, as well as synthetic 1 1 t Media Poly(l:C) Sendai Sendai Sendai virus virus virus X-VCAM-1 HUVEC Treatment X-a4 From www.bloodjournal.org by guest on August 11, 2017. For personal use only. 2949 SICKLECELL ADHERENCE ENHANCED BY VIRUS purified double-stranded RNA, enhance sickle erythrocyte adherence to vascular endothelium in large part through an a4pI-VCAM- l -mediated mechanism. DISCUSSION The present data show that induction of endothelial VCAM-l protein expression by synthetic double-stranded RNA, or by an RNAvirus, increases sickle erythrocyte endothelial adherence under dynamic flow conditions. The sickle erythrocyte adherence appears to occur through interactions between endothelial VCAM-1 and the integrin complex a4PI,known to be expressed on sickle reticulocytes." These data suggest that endothelial cell activation in vivo via double-stranded RNA could initiate sickle erythrocyte adherence and microvascular occlusion. These observations provide a possible mechanism by which viral infection precipitates pain episodes and other vaso-occlusive complications. Double-stranded RNA has been used to model viral effects on endothelial cells in this experimental work. Although poly(1:C) is a synthetic double-stranded RNA that is not a pathogen, it does provide a model for changes that could result from viral infection of endothelial cells by many different RNA viruses with naked double-stranded RNA intermediates. The mechanism responsible for increased VCAM-1 expression in response to poly(1:C) is currently under investigation. Poly(1:C) activates NFKB,'~.*'a transcription factor important in VCAM-1 transcription.26Activation through this mechanism likely contributes to the observed increase in VCAM-1 gene expression after poly(1:C) stimulation. Data presented with parainfluenza 1 virus illustrate that changes in VCAM-1 expression in response to synthetic double-stranded RNA also occur in response to live RNA virus. Other RNA viruses, including measles, also induce VCAM-1 (B. Harcourt and M.K. Offermann, unpublished observation). Studies with intact viruses are complicated by multiple issues, whereas studies with purified viral or synthetic double-stranded RNA allow examination of the effects of a specific macromolecular component present in a diverse array of viruses. Endothelial cells express several proteins that use double-stranded RNA as a cofactor, including the double-stranded RNA-activated protein kinase and 2'-5'-oligoadenylate synthetase." Enzymes activated by doublestranded RNA allow cells to rapidly respond to a wide variety of viruses with change in gene expression. Genes shown to be directly induced by double-stranded RNA are generally proinflammatory, including interferon-a (IFN-a), IFN-p,IL6, IL-l, and cellular adhesion molecules. Thus inflammatory responses can be mounted before cells are able to generate cytotoxic T lymphocytes or antibodies to specific viruses. Endothelial infection by Herpes simplex virus type 1, a DNA virus, has previously been reported to increase sickle erythrocyte adherence in a static assay." The observed adherence appears to be mediated by interactions between endothelial Fc receptors induced by virus and surface-associated IgG on sickle erythrocytes. The erythrocyte-endothelial interactions reported here appear to be mediated by a different mechanism than that reported for Herpes simplex virus. Clinical association of febrile events"with acute pain episodes in sickle cell patients suggests a role for infection in the development of vaso-occlusive pain episodes. Although research has focused on bacterial infection in sickle cell ane~nia,'~.~' viral infection also appears to play a role in causing complications in sickle cell disease. During confirmed cases of infection by the RNA virus influenza B, acute pain episodes have been reported31 andviral infections are thought to precipitate such complications as acute chest ~yndrome.~'Infection is known to activate certain leukocytes, causing release of cytokines such as type I interferons and TNF-a, leading to the development of an antiviral environment in the attacked h o ~ t . ' ~Many , ~ ~ sickle cell patients have been clinically observed to have consistently elevated cytokine levels.35 Induction of VCAM-l directly by viral double-stranded RNA and indirectly by increased cytokine production in response to infection could be beneficial to the host by mounting an inflammatory response to control the infection. However, in the case of sickle cell anemia, VCAM-1 induction is potentially dangerous due to the higher percentage of circulating reticulocytes expressing the counter receptor a4pIthat could adhere, leading to the onset of vascular occlusion. ACKNOWLEDGMENT The authors thank the staff of the Grady Memorial Hospital Sickle Center, especially Joyce Howard Bailey and Patricia Troutman, for their assistance in obtaining blood specimens. REFERENCES 1. Zarkowski HS, Hochmuth RM: Sickling times of individual erythrocytes at zero POz. J Clin Invest 56:1023, 1975 2. Mozzarelli A, Hofrichter J, Eaton WA: Delay time of hemoglobin S polymerization prevents most cells from sickling in vivo. Science 237500, 1987 3. Eaton WA, Hofrichter J: Hemoglobin S gelation and sickle cell disease. Blood 70:1245, 1987 4. Hoover R, Rubin R, Wise G, Warren R: Adhesion of normal and sickle erythrocytes to endothelial monolayer cultures. Blood 54:872, 1979 5. Hebbel RP, Boogaerts MAB, Eaton JW, Steinberg MH: Erythrocyte adherence to endothelium in sickle-cell anemia. A possible determinant of disease severity. N Engl J Med 302:992, 1980 6. Kaul DK, Nagel RL: Sickle cell vasoocclusion: Many issues and some answers. Experimentia 49:5, 1993 7. Wick TM, Moake JL, Udden MM, Eskin SG, Sears DA, McIntire LV: Unusually large von Willebrand multimers increase adhesion of sickle erythrocytes to human endothelial cells under controlled flow. J Clin Invest 80:905, 1987 8. Wick TM, Moake JL, UddenMM, McIntire LV: Unusually large von Willebrand factor multimers preferentially promote young sickle and non-sickle erythrocyte adhesion to endothelial cells. Am J Hematol 42:284, 1993 9. Sugihara K, Sugihara T, Mohandas N, Hebbel RP: Thrombospondin mediates adherence of CD36' sickle reticulocytes to endothelial cells. Blood 80:2634, 1992 10. Brittain HA, Eckman JR, Howard RJ, Wick TM: Thrombospondin from activated platelets promotes sickle erythrocyte adherence to human microvascular endothelium under physiologic flow: A potential role for platelet activation in sickle cell vaso-occlusion. Blood 81:2137, 1993 11. Swerlick RA, Eckman JR, Kumar A, Jeitler M, Wick TM: cY,P,-integrin expression on sickle reticulocytes: Vascular cell adhe- From www.bloodjournal.org by guest on August 11, 2017. For personal use only. 2950 sion molecule-l -dependent binding to endothelium. Blood X2: 1x91, 1993 12. Diggs LW: Sickle cell crisis. Am J Clin Pathol 44: I , 1965 13. Yang J, Hagan MK, Offermann MK: Induction of IL-6 gene expression in Kaposi’s sarcoma cells. J Imlnunol 152943, 1994 14. Yang J, Xu Y, ZhuC, Hagan MK,Lawley T, Offermann MK: Regulation of adhesion molecule expression in Kaposi’s sarcoma cells. J Immunol I52:36 1, I994 IS. Einhorn S, Eldor A, VlodavskyI,Fuks Z, Panet A: Production and characterization of interferon from endothelial cells.J Cell Physio1 122:200, 1985 D: Virustaxonomy, in FieldsBS, 16. MurphyFA,Kingsbury Knipe DM,ChanockRM, Hirsch MS,Melnick JL, MonathTP, Roizman B (eds): Fields Virology (ed I). New York, NY, Raven, 1990, p 9 17. CarterWA,DeClercqE:Viralinfectionandhostdefense. Science 186: I172, 1974 18. Majde JA, Brown RK, Jones MW, Dieffenbach CW, Maitra N. Kruger JM, Cady AB, Smitha CW, Maassab HF: Detection of toxic viral-associated double-stranded RNA (ds RNA) in influenzainfected lung. Microb Pathog 10: 105, 199 I 19. Kimura-Takeuchi M, Majde JA, Toth LA, Krueger JM: The role of double-strandedRNA in induction of theacute phase response in an abortive influenza virus infection model. J Infect Dis 166:1266, I992 20. Garfinkel S, Haines D, Brown S, Wessendorf J, Gillespie D. Maciag T: Interleukin-la mediates an alternative pathway for the antiproliferative action of poly(1:C) on human endothelial cells. J Biol Chem 267:24375, 1992 21. Offennann MK, Medford R: Induction of VCAM-l gene expression by double stranded RNA occurs by a p68 kinase-dependent pathway in endothelial cells. Clin Res 412:262A, 1993 22. Jaffe EA, Nachman RL, Becker CG, Minick CR: Culture of human endothelial cells derived from umbilical veins. Identification J Clin Invest 52:2745, by morphologicandimmunologiccriteria. I973 SMOLlNSKl ET AL 73. Britlain HA. Eckman JR, Wick TM: Sickle erythrocyte adherence to large vessel and microvascular endothelium under physiologic flow is qualitatively different. J Lab Clin Med 12O:S3X, 1992 24. Hines WW,Montgomery DC: ProbabilityandStatistics in Engineering and Management Science. New Yorh. NY, Wiley, I990 25. Visvanathan KV. Goodbourn, S: Double-stranded RNA aclivates binding of NF-kappa B to an inducible element i n the human beta-interferon promoter. EMBO J 8:l 129, 1989 26. lademarco MF, McQuillan JJ, Rosen GD, Dean DC: Characterization of the promoterforvascular cell adhesionmolecule-I (VCAM-I 1. J Biol Chem 267:16323. 1992 27. Hebbel RP, Visser MR, Goodman JL, Jacob HS, Vercellotti GM: Potentiatedadherence of slckleerythrocytes t o endothelium infected by virus. J Clin Invest 80:1503, 19x7 78. Baum KE, Dunn DT, Maude CH. Serjeant GR: The painful crisis of homo7ygous sickle cell disease. Arch Intern Med 147:123 I . 19x7 29. Barrett-Connor E: Bacterial infection and sickle cell anemia. Medicine 50:97. I97 I 30. WinkelsteinJA:Pneumococcalinfections in sickle cell diseaae. J Pediatr 9 1 : S 2I . I977 3 l . Turner EA, Thompson HD, Reddy CM, South MA, GarrettEllis BR, Mirkovic RR: Sickle cell disease with complicated influenza B virus infection. J Natl Med Assoc 84524, 1992 32. Poncz M, Kane E, Gill FM: Acute chest syndrome in sickle cell disease: Etiology and clinical correlates. J Pediatr 107:861, 1985 33. Goldfeld AE, Maniatis T: Coordinate viral induction of tumor necrosis factor (Y and interferon 0 in human B cells and monocytes. Proc Natl Acad Sci USA 86:1490, 1989 34. Wathelet MC, Berr PM, Huez GA: Regulation of gene expression by cytokines and virus in human cells lacking the type-l interferon locus. Eur J Biochem 206:901, 1992 35. FrancisRB,Haywood LJ: Elevatedimmunoreactivelumor necrosis tictor and interleukin-l in sickle cell disease. J Natl Med Assoc 8 4 3 1 l , 1992 From www.bloodjournal.org by guest on August 11, 2017. For personal use only. 1995 85: 2945-2950 Double-stranded RNA induces sickle erythrocyte adherence to endothelium: a potential role for viral infection in vaso-occlusive pain episodes in sickle cell anemia PA Smolinski, MK Offermann, JR Eckman and TM Wick Updated information and services can be found at: http://www.bloodjournal.org/content/85/10/2945.full.html Articles on similar topics can be found in the following Blood collections Information about reproducing this article in parts or in its entirety may be found online at: http://www.bloodjournal.org/site/misc/rights.xhtml#repub_requests Information about ordering reprints may be found online at: http://www.bloodjournal.org/site/misc/rights.xhtml#reprints Information about subscriptions and ASH membership may be found online at: http://www.bloodjournal.org/site/subscriptions/index.xhtml Blood (print ISSN 0006-4971, online ISSN 1528-0020), is published weekly by the American Society of Hematology, 2021 L St, NW, Suite 900, Washington DC 20036. Copyright 2011 by The American Society of Hematology; all rights reserved.