MONOCLONAL-ANTIBODIES TO SURFACE-EXPOSED PROTEINS OF MYCOPLASMA-MYCOIDES SUBSP MYCOIDES (SMALL-COLONY STRAIN), WHICH CAUSES CONTAGIOUS BOVINE PLEUROPNEUMONIA

Outbreaks of bovine pleuropneumonia caused by small-colony strains of Mycoplasma mycoides subsp. mycoides occur in Africa, and vaccination i s used for control. Since protein subunits are needed to improve multi valent vaccines, monoclonal antibodies (MAbs) were made to facilitate protein identification and isolation, Eleven immunoglobulin hi MAbs de rived from mouse spleen donors immunized with disrupted whole organism s bound periodate-sensitive epitopes on externally exposed polysacchar ide. Seven of these MAbs caused in vitro growth inhibition of M. mycoi des subsp. mycoides; however, reaction with carbohydrate epitopes prev ented their use in identifying proteins. Ten additional MAbs from mous e spleen donors immunized with Triton X-114-phase integral membrane pr oteins reacted with periodate-insensitive, proteinase K-sensitive epit opes. These MAbs were classified into three groups based on immunoblot s of Triton X-114-phase proteins. One group reacted with 96-, 16-, and 15-kDa proteins. Another group reacted with 26-, 21-, and 16-kDa prot eins, while a third group reacted only with 26- and 21-kDa proteins. O ne MAb from each group reacted with trypsin-sensitive epitopes on live organisms, yet none caused in vitro growth inhibition. Representative MAbs reacted with all small-colony strains in immunoblots and did not react with large-colony strains, However, these MAbs were not specifi c for small-colony strains, as proteins from two other M. mycoides clu ster organisms were identified. Nevertheless, MAbs to surface-exposed epitopes on integral membrane proteins will be useful for isolation of these proteins for immunization, since one or more might induce growt h-inhibiting antibodies or other protective responses.