RESUMO
Activation of B and T lymphocytes leads to major remodelling of the metabolic landscape of the cells enabling their post-activation functions. However, naive B and T lymphocytes also show metabolic differences, and the genesis, nature and functional significance of these differences are not yet well understood. Here we show that resting B-cells appeared to have lower energy demands than resting T-cells as they consumed lower levels of glucose and fatty acids and produced less ATP. Resting B-cells are more dependent on OXPHOS, while T-cells show more dependence on aerobic glycolysis. However, despite an apparently higher energy demand, T lineage cells showed lower rates of protein synthesis than equivalent B lineage stages. These metabolic differences between the two lineages were established early during lineage differentiation, and were functionally significant. Higher levels of protein synthesis in B-cells were associated with increased synthesis of MHC class II molecules and other proteins associated with antigen internalization, transport and presentation. The combination of higher energy demand and lower protein synthesis in T-cells was consistent with their higher ATP-dependent motility. Our data provide an integrated perspective of the metabolic differences and their functional implications between the B and T lymphocyte lineages.
Assuntos
Linfócitos B/metabolismo , Glicólise/imunologia , Fosforilação Oxidativa , Linfócitos T/metabolismo , Trifosfato de Adenosina/biossíntese , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Ácidos Graxos/metabolismo , Expressão Gênica , Glucose/metabolismo , Glicólise/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Imunofenotipagem , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Especificidade de Órgãos , Cultura Primária de Células , Biossíntese de Proteínas/imunologia , Linfócitos T/citologia , Linfócitos T/imunologiaAssuntos
Carcinoma Hepatocelular/diagnóstico , Células Gigantes/citologia , Átrios do Coração/patologia , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/secundário , Neoplasias Hepáticas/diagnóstico , Fígado/patologia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/secundário , Histocitoquímica , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Masculino , Microscopia , Pessoa de Meia-IdadeRESUMO
SUMMARY: We report a case of juvenile myelomonocytic leukemia (JMML) with coexistent cytomegalovirus (CMV) infection in a 10-month-old child that caused initial diagnostic dilemma. The patient presented with fever, anemia, lymphadenopathy, and hepatosplenomegaly. The peripheral blood smear and bone marrow aspirate examination showed monocytosis, leukoerythroblastosis, myeloid hyperplasia, and increased blasts. Serologic test for CMV was positive and thus the hematologic picture was attributed to CMV infection and gancyclovir was started. The patient, however, did not improve clinically. A repeat peripheral smear and marrow showed persistence of the above picture and a diagnosis of JMML was made. Viral infections in young children may present with hematologic features overlapping with JMML and simultaneous occurrence of both may cause diagnostic dilemma.