ABSTRACT
OBJECTIVES: Monoclonal antibodies against human Pneumocystis carinii were produced by fusion of myeloma cells (X63-AG8.653) with splenocytes from Biozzi mice that had been immunized against P. carinii cysts isolated from infected human lung. The aim of this study was to evaluate the usefulness of these monoclonal antibodies for the diagnosis of P. carinii pneumonia by indirect immunofluorescence in comparison with a modified silver stain method and commercial kits. METHODS: One hundred fifty-seven specimens from 87 patients, infected or non-infected with human immunodeficiency virus, were examined for the presence of P. carinii. Specimens were either induced sputum samples or bronchoalveolar lavage fluids. Indirect immunofluorescence was performed with six stable clones obtained by limiting dilution. Four of the monoclonal antibodies were IgG1 isotypes, one was an IgG3 and one was an IgM. Their isoelectric points varied from 6.5 to 8.3. Tests were also performed with silver methenamine staining and with two commercially available monoclonal antibodies (Monofluo kit from Diagnostics Pasteur and MAb from Dako). RESULTS: The 6 antibodies all recognized P. carinii cysts in indirect immunofluorescence. No cross reactivity was observed with yeast or host cells. P. carinii antigens could not be identified with western immunoblotting suggesting that the monoclonal antibodies recognized native antigens. This result was confirmed by dot blot analysis. Spots were observed with native but not with denatured antigens. Inhibition studies showed that these 6 antibodies recognized the same or overlapping sites. The sensitivities of detection of P. carinii in sputum were 87% by silver stain and from 93.5 to 96.7% by immunofluorescence. The sensitivities of detection in bronchoalveolar lavage were 67.3% by silver stain and from 75.7% to 76.8% by immunofluorescence. CONCLUSION: Immunofluorescence was more sensitive than silver staining and the best results were obtained with E5-8 and A8-13 monoclonal antibodies and with Monofluo kit.
Subject(s)
Antibodies, Monoclonal , Fluorescent Antibody Technique , Pneumocystis/immunology , Pneumonia, Pneumocystis/diagnosis , Animals , Antibodies, Monoclonal/isolation & purification , Antigens, Fungal/immunology , Bronchoalveolar Lavage Fluid/immunology , Electrophoresis , Humans , Immunoblotting , Mice , Pneumonia, Pneumocystis/immunology , Rabbits , Reagent Kits, Diagnostic , Sensitivity and Specificity , Silver Staining , Sputum/immunologyABSTRACT
To determine if rotavirus interferes with the multiplication of poliovirus, and hence the efficiency of the polio vaccine, the effect of timing and concentration of Simian rotavirus (SSA-11) on polio-1 infection in MA-104 cells was studied in vitro by evaluating the cytopathic effect, the reduction of the infectivity titers and the visualization of viral particles by electron microscopy. We found that poliovirus 1 was able to replicate when the challenge dose was administered within the first 8 h following SA-11 infection and with titers ten times lower than those of rotavirus. Hence, non-interference effect was observed in this in vitro model.
