Abstract
One of the major surface structures of Ureaplasma urealyticum recognized by antibodies of patients during infection is the MB antigen. Previously, we showed by Western blot (immunoblot) analysis that any one of the anti-MB monoclonal antibodies (MAbs) 3B1.5, 5B1.1, and 10C6.6 could block the binding of patient antibodies to MB. Subsequent DNA sequencing revealed that a unique six-amino-acid direct tandem repeat region composed the carboxy two-thirds of this antigen. In the present study, using antibody-reactive peptide scanning of this repeat region, we demonstrated that the amino acids defining the epitopes for MAbs 3B1.5 5B1.1 and 10C6.6 are EQP, GK, and KEQPA, respectively. Peptide scanning analysis of an infected patient's serum antibody response showed that the dominant epitope was defined by the sequence PAGK. Mapping of these continuous epitopes revealed overlap between all MAb and patient polyclonal antibody binding sites, thus explaining the ability of a single MAb to apparently block all polyclonal antibody binding sites. We also show that a single amino acid difference in the sequence of the repeats of serovars 3 and 14 accounts for the lack of reactivity with serovar 14 of two of the serovar 3-specific MAbs. Finally, the data demonstrate the need to obtain the sequences of the mba genes of all serovars before an effective serovar-specific antibody detection method can be developed.
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- Cassell G. H., Waites K. B., Crouse D. T., Rudd P. T., Canupp K. C., Stagno S., Cutter G. R. Association of Ureaplasma urealyticum infection of the lower respiratory tract with chronic lung disease and death in very-low-birth-weight infants. Lancet. 1988 Jul 30;2(8605):240–245. doi: 10.1016/s0140-6736(88)92536-6. [DOI] [PubMed] [Google Scholar]
- Cassell G. H., Waites K. B., Watson H. L., Crouse D. T., Harasawa R. Ureaplasma urealyticum intrauterine infection: role in prematurity and disease in newborns. Clin Microbiol Rev. 1993 Jan;6(1):69–87. doi: 10.1128/cmr.6.1.69. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chou P. Y., Fasman G. D. Prediction of the secondary structure of proteins from their amino acid sequence. Adv Enzymol Relat Areas Mol Biol. 1978;47:45–148. doi: 10.1002/9780470122921.ch2. [DOI] [PubMed] [Google Scholar]
- Emini E. A., Hughes J. V., Perlow D. S., Boger J. Induction of hepatitis A virus-neutralizing antibody by a virus-specific synthetic peptide. J Virol. 1985 Sep;55(3):836–839. doi: 10.1128/jvi.55.3.836-839.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jameson B. A., Wolf H. The antigenic index: a novel algorithm for predicting antigenic determinants. Comput Appl Biosci. 1988 Mar;4(1):181–186. doi: 10.1093/bioinformatics/4.1.181. [DOI] [PubMed] [Google Scholar]
- Kaplan A. H., Manchester M., Swanstrom R. The activity of the protease of human immunodeficiency virus type 1 is initiated at the membrane of infected cells before the release of viral proteins and is required for release to occur with maximum efficiency. J Virol. 1994 Oct;68(10):6782–6786. doi: 10.1128/jvi.68.10.6782-6786.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kyte J., Doolittle R. F. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. doi: 10.1016/0022-2836(82)90515-0. [DOI] [PubMed] [Google Scholar]
- Shi P. T., Riehm J. P., Todd P. E., Leach S. J. The antigenicity of myoglobin-related peptides synthesised on polyacrylamide and polystyrene resin supports. Mol Immunol. 1984 Jun;21(6):489–496. doi: 10.1016/0161-5890(84)90064-6. [DOI] [PubMed] [Google Scholar]
- Teng L. J., Zheng X., Glass J. I., Watson H. L., Tsai J., Cassell G. H. Ureaplasma urealyticum biovar specificity and diversity are encoded in multiple-banded antigen gene. J Clin Microbiol. 1994 Jun;32(6):1464–1469. doi: 10.1128/jcm.32.6.1464-1469.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tribbick G., Triantafyllou B., Lauricella R., Rodda S. J., Mason T. J., Geysen H. M. Systematic fractionation of serum antibodies using multiple antigen homologous peptides as affinity ligands. J Immunol Methods. 1991 Jun 3;139(2):155–166. doi: 10.1016/0022-1759(91)90185-i. [DOI] [PubMed] [Google Scholar]
- Waites K. B., Crouse D. T., Cassell G. H. Ureaplasma and mycoplasma CNS infections in newborn babies. Lancet. 1990 Mar 17;335(8690):658–659. doi: 10.1016/0140-6736(90)90442-8. [DOI] [PubMed] [Google Scholar]
- Waites K. B., Duffy L. B., Crouse D. T., Dworsky M. E., Strange M. J., Nelson K. G., Cassell G. H. Mycoplasmal infections of cerebrospinal fluid in newborn infants from a community hospital population. Pediatr Infect Dis J. 1990 Apr;9(4):241–245. doi: 10.1097/00006454-199004000-00004. [DOI] [PubMed] [Google Scholar]
- Watson H. L., Blalock D. K., Cassell G. H. Variable antigens of Ureaplasma urealyticum containing both serovar-specific and serovar-cross-reactive epitopes. Infect Immun. 1990 Nov;58(11):3679–3688. doi: 10.1128/iai.58.11.3679-3688.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zheng X., Teng L. J., Watson H. L., Glass J. I., Blanchard A., Cassell G. H. Small repeating units within the Ureaplasma urealyticum MB antigen gene encode serovar specificity and are associated with antigen size variation. Infect Immun. 1995 Mar;63(3):891–898. doi: 10.1128/iai.63.3.891-898.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zheng X., Watson H. L., Waites K. B., Cassell G. H. Serotype diversity and antigen variation among invasive isolates of Ureaplasma urealyticum from neonates. Infect Immun. 1992 Aug;60(8):3472–3474. doi: 10.1128/iai.60.8.3472-3474.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]