Exploring the feasibility of an anti-idiotypic cocaine vaccine: analysis of the specificity of anticocaine antibodies (Ab1) capable of inducing Ab2beta anti-idiotypic antibodies.

Conventional vaccination with the cocaine molecule conjugated to a protein carrier is a new approach in the treatment of addiction. Experimentally, this strategy has been shown to alter the pharmacokinetics as well as the psychostimulant effect of a cocaine challenge. The purpose of this study was to investigate whether a more stable and less controversial molecule, an anti-idiotypic antibody, which mimics the configuration of the cocaine molecule (Ab2beta), could be successfully used instead of cocaine. Two cocaine conjugates that presented different areas of the cocaine molecule to the immune system were used to produce monoclonal antibodies specific for cocaine (Ab1). Several anti-idiotypic antibodies were then produced. Four were identified as Ab2beta, or internal images of the antigen; when injected into BALB/c mice, they elicited an anticocaine response. The anticocaine response elicited by one of the four Ab2beta (K1-4c) was sufficient to significantly reduce the level of cocaine that targeted the brain following cocaine challenge, compared with the level of cocaine found in the brain of control animals immunized with irrelevant antibody. In conclusion, the possibility of an anti-idiotypic vaccine seems to be worth pursuing.

Definition of the specificity of monoclonal antibodies against porcine CD45 and CD45R: report from the CD45/CD45R and CD44 subgroup of the Second International Swine CD Workshop.

Swine cell binding analyses of a set of 48 monoclonal antibodies (mAbs), including eleven standards, assigned to the CD44 and CD45 subset group of the Second International Swine CD Workshop yielded 13 clusters. Although none of these corresponded to CD44, seven mAbs formed a cluster which was identified as being specific for restricted epitopes of CD45 (CD45R). In addition, a T-cell subset specific cluster comprised of four mAbs was also identified. Two mAbs (STH106 and SwNL 554.1) reacted exclusively with CD8 bright lymphocytes, the other two (2B11 and F01G9) with a subset of CD4 lymphocytes. The other 10 clusters were either specific for MHC-class I like molecules or overlapped with clusters identified by the adhesion molecule subgroup and are therefore just briefly discussed in this report. The specificity of all the mAbs in the CD45R cluster was verified by their ability to immunoprecipitate distinct proteins and to react with CHO cells expressing individual isoforms of CD45. Three CD45R mAbs (3a56, MIL5, -a2) did react with a 210 kDa isoform(s), while another three (STH267, FG2F9, 6E3/7) only recognized a 226 kDa isoform(s). The remaining one (MAC326) precipitated both a 210 and 226 kDa protein. The specificity of all the mAbs in the CD45R cluster, and of the CD45 common mAbs, was confirmed by their reactivity with CHO cells transfected with cDNAs encoding the extracellular and transmembrane portions of distinct CD45R isoforms. Those mAbs recognizing a 210 kDa protein reacted with CHO cells expressing the CD45RC isoform, while those capable of precipitating a 226 kDa, but not the 210 kDa, polypeptide recognized CHO cells expressing either the CD45RAC and the relatively rare CD45RA isoform. MAC326 was unique in its inability to react with CHO cells engineered to produce the CD45RC and CD45RAC isoforms. Thus, three mAbs (6E3/7, STH267, and FG2F9) appear to be specific for an epitope(s) encoded by the A exon, while one (MAC326) recognizes a determinant encoded by the C exon. The remaining three mAbs (3a56, -a2, MIL5) are apparently specific for an epitope(s) which results from the fusion of the C exon to the invariant leader sequence and is destroyed by inclusion of the A exon. All three CD45 common mAbs, K252.1E4, MAC323 and 74.9.3, did react with the CHO cells lines expressing either the CD45RA, CD45RC, CD45RAC or CD45RO isoforms, but not with untransfected CHO cells. When the natural expression of CD45 isoforms was examined by reacting lymphocytes with CD45R mAbs, a high level expression of isoforms containing the A exon-generated domain was detected in all B cells while the majority of CD4+ T cells had undetectable or lower expression density of this protein than B cells. In contrast, the density of expression of the CD45 isoform(s) containing the C exon-generated domain ranged from undetectable to high in CD4+ T cells whereas the amounts were approximately ten-fold lower in B cells. Overall this panel of CD45 mAbs will be very useful in analyzing the maturation and differentiation of swine lymphoid cells subsets.

Biochemical analysis of molecules reactive with monoclonal antibodies specific for porcine CD45.

The apparent molecular weight of molecules reactive with eight mAbs, which were identified during the First International Swine CD Workshop as putatively specific for porcine CD45, was determined by immunoprecipitation analysis of 125I surface-labeled peripheral blood mononuclear cells. Four putative CD45 specific mAbs (K252.1E4, MAC323, 74-9-3 and 2A5) precipitated three polypeptides of 226, 210 and 190 kDa. Two putative CD45R specific mAbs (MAC326 and MAC327) precipitated two polypeptides with an apparent molecular weight of 226 and 210 kDa, while another two (3a56 and -a2) precipitated a single polypeptide of 210 kDa. Sequential immunoprecipitations analyses indicated that the comigrating molecules precipitated by the CD45 and CD45R were the same. The results from this study confirmed the assignment of mAbs K252.1E4, MAC323, 74-9-3 and 2A5 as CD45, and mAbs MAC326, MAC327, 3a56 and -a2, as CD45R. These CD45 and CD45R specific mAbs should prove to be valuable reagents for the study of the porcine immune system.