This work reports the in vitro expression of Citrus leprosis virus C (CiLV-C) putative coat protein (p29) and the production of a polyclonal antibody to be used as a tool for serological diagnosis of citrus leprosis. The ORF2/RNA1, corresponding to p29, was cloned in pET28a and transformed into Escherichia coli cells (BL21). Expression of p29 was induced in vitro and the protein was purified and used for immunization of rabbits to produce the polyclonal antibody. The anti p29 serum was shown to be highly specific to CiLV-C detection by immunological methods (Western blot, PTA-ELISA, tissue blot and in situ immunolocalization), without cross reaction with healthy citrus plants or other cytoplasmic and nuclear viruses transmitted by Brevipalpus mites. These results demonstrate that the antibody against CiLV-C p29 protein is highly specific for CiLV-C detection. In situ immunogold labeling assays on thin sections of sweet orange leaf cells infected by CiLV-C demonstrated that short, bacilliform particles present within cisternae of the endoplasmic reticulum were specifically labeled, confirming their viral nature. The dense cytoplasmic viroplasm was also heavily labeled indicating that it represents a site of p29 accumulation.

CONTEXTO: Neste trabalho foi estudada a alteração molecular em um paciente brasileiro de 72 anos com talassemia beta homozigótica com evolução clínica intermediária, esplenectomizado e necessitando de transfusões ocasionais. Os dados hematológicos mostravam anemia microcítica e hipocrômica (Hemoglobina = 7,9 g/dl, Volume Corpuscular Médio = 76fl, Hemoblobina Corpuscular Média = 26 pg) e a eletroforese de hemoglobina revelou Hemoglobina Fetal = 14,2%, Hemoglobina A2 = 6,2% e Hemoglobina A = 79,4%. OBJETIVO: Identificar as duas mutações envolvendo um paciente com sintomas de talassemia beta intermediária. TIPO DE ESTUDO: Investigação molecular das possíveis mutações responsáveis pelo quadro clínico descrito. LOCAL: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, São Paulo, Brasil. PROCEDIMENTOS: Após a extração de DNA do sangue deste paciente, foi feita reação de polimerase em cadeia (polymerase chain reaction, PCR) utilizando cinco pares de primers que amplificaram éxons e a região promotora do gene da globina beta. O produto da amplificação foi seqüenciado e os cromatogramas, analisados por programas de computador (Phred, Phrap e Consed). RESULTADOS: Foram encontradas duas mutações responsáveis pela doença;-101 (C > T) e códon 39 (C > T). CONCLUSÕES: Este caso representa a primeira descrição da mutação 101 (C > T) na população brasileira e está associado a evolução clínica benigna.

CONTEXT: We verified molecular alterations in a 72-year-old Brazilian male patient with a clinical course of homozygous beta-thalassemia intermedia, who had undergone splenectomy and was surviving without regular blood transfusions. The blood cell count revealed microcytic and hypochromic anemia (hemoglobin = 6.5 g/dl, mean cell volume = 74 fl, mean cell hemoglobin = 24 pg) and hemoglobin electrophoresis showed fetal hemoglobin = 1.3%, hemoglobin A2 = 6.78% and hemoglobin A = 79.4%. OBJECTIVE: To identify mutations in a patient with the symptoms of beta-thalassemia intermedia. DESIGN: Molecular inquiry into the mutations possibly responsible for the clinical picture described. SETTING: The structural molecular biology and genetic engineering center of the Universidade Estadual de Campinas, Campinas, Brazil. PROCEDURES: DNA extraction was performed on the patient's blood samples. The polymerase chain reaction (PCR) was done using five specific primers that amplified exons and the promoter region of the beta globin gene. The samples were sequenced and then analyzed via computer programs. RESULTS: Two mutations that cause the disease were found: -101 (C > T) and codon 39 (C > T). CONCLUSIONS: This case represents the first description of 101 (C > T) mutation in a Brazilian population and it is associated with a benign clinical course.