Preliminary investigation of an age-related differential expression of CD45 isoforms in murine lymphocytes

A panel of monoclonal anti-CD45 antibodies has been employed in one-dimensional SDS-PAGE and Western blotting to investigate putative age-related differential expression of CD45 isoforms among thymic and peripheral lymphocytes of newly-born, young and aged BALB/c mice. Both tissue-specific and age-dependent differences in CD45 isoform expression were notable in blots of total, PNA(+) (immature) and PNA(-) (mature) thymocytes and splenocytes of each of the specified age groups of mice, probed by either mAb 30-F11 (specific to all conventional CD45 isoforms), mAb 14.8 (specific to an exon A-dependent epitope), mAb C363.16A (specific to an exon B-dependent epitope), or mAb CT1 (specific to a CD45-associated glycan epitope). Although our observations were indicative of a lack of an age-related distinction in exon A-dependent epitope utilization, salient age-related differences were observed in exon B-dependent epitope utilization as well as the mode of expression of the glycan epitope. The observed age-dependent structural alterations of CD45 isoform expression may be correlated to impairment of lymphocyte function during the ageing process.