#SERIAL CLONER LINEAR TO CIRCULAR SERIAL#

These data suggest that SLDs and CD-1 may arise from an evolutionarily conserved chromosomal reservoir.Ībstract = 'We have detected several new chromosome-sized DNAs in lines derived from the LT252 isolate of Leishmania major. donovani possess a homologous 1.5 Mb chromosome containing both the CD-1 and 715 sequences within a 40-kb region, whose size remained unaltered following appearance of the SLDs. braziliensis, however the 715-class SLD probe did not identify CD-1 itself. major 715 class of SLDs in addition to the LD-1 DNAs of L. A cloned probe derived from CD-1 (from K. A 715-class SLD hybridization probe also identified small chromosomes described previously in Leishmania donovani (LD-1, HU-3 minichromosome) and Leishmania braziliensis (LD-1) LD-1 is known to be related to a smaller circular DNA, CD-1. Southern blot hybridization revealed that all four new DNAs were related, and the family was designated the 715 class of small linear DNAs (SLDs). The new chromosomes were present in multiple copies, stably maintained, linear, and hybridized to a telomere-specific probe, and ranged in size from 180 to 220 kb. No association of these new DNAs with drug resistance was detected.

#SERIAL CLONER LINEAR TO CIRCULAR SERIAL#

These DNAs appeared de novo in two clonal lines undergoing methotrexate (MTX) selection (clone 7-R50, clone 15-R50), in a stably MTX-resistant population reverting from MTX pressure (R 1000-11-P55rev), and spontaneously during routine serial passage of the wild-type LT252 line in vitro (LT252+). A possible rituximab interaction with ASMLPD is suggested.We have detected several new chromosome-sized DNAs in lines derived from the LT252 isolate of Leishmania major. Our results show a unique fine specificity of rituximab, define the molecular basis for the lack of rituximab reactivity with mouse CD20 (mCD20), and the potential of targeting CD20 in an active immunotherapy setting. Peptides induced antibodies with specificity and effector functions similar to those of rituximab. Anti-CD20 mAb 1F5 only displayed a reactivity profile similar to that of rituximab, which also reacted with ASMLPD-derived peptides. The WPXWLE motif expressed by the linear PDPL-derived clone insert sequences could only be aligned to the reverse-oriented 161WPXWLE 156 of acid sphingomyelinase-like phosphodiesterase 3b precursor (ASMLPD), though linear peptides bearing WPXWLE competed with cyclic ones for rituximab-paratope binding.

P 172 was the most critical for rituximab binding, since its replacement with S 172 (of mouse CD20) abolished the reactivity.

Rituximab-specific c7c PDPL-derived clone insert sequences expressed the motif A(S)NPS overlapping the human CD20 170ANPS 173. To improve our understanding of rituximab's function, its fine specificity was investigated by means of phage display peptide library (PDPL)-expressing 7-mer cyclic (c7c) or 7-/12-mer linear peptides. Heterogeneity of the effector functions displayed by rituximab and other anti-CD20 monoclonal antibodies (mAbs) apparently recognizing the same CD20 epitope suggests that additional mechanisms, probably related to mAb fine specificity, are responsible for B-cell depletion.

Serial cloner linear to circular