Molecular mimicry in the chronic myeloproliferative disorders: reciprocity between quantitative JAK2 V617F and Mpl expression.
An activating JAK2 mutation (JAK2 V617F) is present in the chronic myeloproliferative disorders (MPDs), polycythemia vera (PV), idiopathic myelofibrosis (IMF), and essential thrombocytosis (ET). JAK2 is also a chaperone for Mpl and responsible for its cell-surface expression. We observed a reciprocal relationship between neutrophil JAK2 V617F allele percentage and platelet Mpl expression in JAK2 V617F-positive PV, IMF, and ET patients. However, severely impaired platelet Mpl expression was present in JAK2 V617F-negative MPD patients. While JAK2 V617F allele status did not necessarily correlate with the clinical MPD phenotype, the degree of impaired platelet Mpl expression did. We conclude that multiple molecular abnormalities are involved in the pathogenesis of the MPDs and that aberrant Mpl expression may be a common denominator of aberrant signaling in both the JAK2 V617F-positive and JAK2 V617F-negative MPDs.
Moliterno
Alison R
AR
Johns Hopkins University School of Medicine, Ross Research 1025, 720 Rutland Ave, Baltimore, MD 21205, USA. amoliter@jhmi.edu
Williams
Donna M
DM
Rogers
Ophelia
O
Spivak
Jerry L
JL
D000483:Alleles; D019943:Amino Acid Substitution; D001792:Blood Platelets / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D006801:Humans; D053614:Janus Kinase 2 / Q000096:biosynthesis* / Q000235:genetics; D018832:Molecular Chaperones / Q000096:biosynthesis* / Q000235:genetics; D018716:Molecular Mimicry / Q000235:genetics; D020125:Mutation, Missense; D009196:Myeloproliferative Disorders / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D053628:Receptors, Thrombopoietin / Q000096:biosynthesis* / Q000235:genetics
D018832:Molecular Chaperones; D053628:Receptors, Thrombopoietin; C082218:MPL protein, human; C507924:JAK2 protein, human; D053614:Janus Kinase 2