RESUMO
Kaposi sarcoma herpesvirus (KSHV/HHV-8) is a B cell tropic human pathogen, which is present in vivo in monotypic immunoglobulin λ (Igλ) light chain but polyclonal B cells. In the current study, we use cell sorting to infect specific B cell lineages from human tonsil specimens in order to examine the immunophenotypic alterations associated with KSHV infection. We describe IL-6 dependent maturation of naïve B lymphocytes in response to KSHV infection and determine that the Igλ monotypic bias of KSHV infection in vivo is due to viral induction of BCR revision. Infection of immunoglobulin κ (Igκ) naïve B cells induces expression of Igλ and isotypic inclusion, with eventual loss of Igκ. We show that this phenotypic shift occurs via re-induction of Rag-mediated V(D)J recombination. These data explain the selective presence of KSHV in Igλ B cells in vivo and provide the first evidence that a human pathogen can manipulate the molecular mechanisms responsible for immunoglobulin diversity.
Assuntos
Linfócitos B/metabolismo , Rearranjo Gênico , Infecções por Herpesviridae/genética , Herpesvirus Humano 8/patogenicidade , Cadeias lambda de Imunoglobulina/genética , Linfócitos B/imunologia , Linfócitos B/virologia , Células Cultivadas , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/virologia , Herpesvirus Humano 8/genética , HumanosRESUMO
Myeloproliferative neoplasia (MPN)-associated pulmonary hypertension (PH) is included in group five of the most recent clinical classification of PH.1 The MPNs are a heterogeneous group of disorders that includes disorders with primary expression of a myeloid phenotype and disorders characterized by expression of the Janus Kinase 2 (JAK2) mutation, p.V617F. The latter includes essential thrombocytosis, polycythemia vera, and idiopathic myelofibrosis.2 Pulmonary extra-medullary hematopoiesis (EMH) refers to the presence of hematopoietic precursor cells in the lung. It is a rare complication associated with myelofibrosis. Here we present a case series highlighting the clinical-pathological-radiological features of pulmonary EMH and PH from underlying polycythemia vera.
RESUMO
Intercellular bridges may aide in definitive identification of malignant cell origin, especially in squamous cell carcinoma. They are difficult to identify in routine cytologic specimens and are especially rare in smear preparations. Herein, we present images of intercellular bridges from a case of well differentiated squamous cell carcinoma of the esophagus in a cytologic specimen obtained from FNA of a paraesophageal lymph node.