RESUMO
A series of benzindazole-4,9-quinones was tested for growth-inhibitory effects on Cryptosporidium parvum in vitro and in vivo. Most compounds showed considerable activity at concentrations from 25 to 100 micro M. For instance, at 25 micro M the derivatives 5-hydroxy-8-chloro-N1-methylbenz[f]-indazole-4,9-quinone and 5-chloro-N2-methylbenz[f]indazole-4,9-quinone inhibited growth of C. parvum 78-100%, and at 50 micro M seven of the 23 derivatives inhibited growth > or = 90%. The activity of the former two compounds was confirmed in a T-cell receptor alpha (TCR-alpha)-deficient mouse model of chronic cryptosporidiosis. In these mice, the mean infectivity scores (IS) in the caecum were 0.63-0.20, whereas in sham-treated mice the score was 1.44 (P < 0.05). There were similar differences in IS in the ileum, where the score for treated mice was 1.12-0.20 and that for mice receiving no drug was 1.32. There was no acute or chronic toxicity for any compound tested in vivo.
Assuntos
Criptosporidiose/tratamento farmacológico , Cryptosporidium parvum/efeitos dos fármacos , Cryptosporidium parvum/crescimento & desenvolvimento , Quinonas/farmacologia , Quinonas/uso terapêutico , Animais , Bovinos , Doenças do Ceco/tratamento farmacológico , Doenças do Ceco/microbiologia , Linhagem Celular , Criptosporidiose/microbiologia , Cryptosporidium parvum/isolamento & purificação , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Células Epiteliais/efeitos dos fármacos , Genes Codificadores da Cadeia alfa de Receptores de Linfócitos T/efeitos dos fármacos , Genes Codificadores da Cadeia alfa de Receptores de Linfócitos T/fisiologia , Humanos , Doenças do Íleo/tratamento farmacológico , Doenças do Íleo/microbiologia , Camundongos , Quinonas/química , Quinonas/isolamento & purificaçãoRESUMO
Chronic beryllium disease (CBD) is caused by beryllium exposure and is characterized by granulomatous inflammation with accumulation of CD4+ T cells in the lung. We analyzed TCR beta-chain and alpha-chain genes expressed by these CD4+ T cells. In the lungs of individual patients, as well as among four of five CBD patients studied, different oligoclonal expansions within the Vbeta3 subset were found to express homologous or even identical CDR3 amino acid sequences. These related expansions were specific for CBD patients, were compartmentalized to lung, and persisted at high frequency in patients with active disease. Limiting dilution cloning and analysis of coexpressed TCR alpha-chain genes confirmed that these TCRs were selectively expanded by a common Ag involving beryllium. Overall, homologous TCR beta- and alpha-chains showed identical V regions and invariant charged residues within the CDR3 but considerable variability in TCRJ usage. Remarkably, CBD patients expressing nearly identical TCRs did not share common HLA-DRB1 or DQ alleles. These results implicate particular CD4+ cells in the pathogenesis of CBD and provide insight into how beryllium is recognized in human disease.