Distribution of carboxypeptidase M on lymphoid and myeloid cells parallels
the other zinc-dependent proteases CD10 and CD13
B de Saint-Vis, L Cupillard, D Pandrau-Garcia, S Ho, N Renard, G Grouard, V Duvert, X Thomas, JP Galizzi and J Banchereau
Laboratory for Immunological Research, Schering-Plough, Dardilly, France.
Monoclonal antibody (MoAb) M27 was generated after immunization of mice
with the human B-lineage acute lymphoblastic leukemia cell line Pre- ALP.
Under reducing conditions, MoAb M27 precipitated a 60-kD surface- membrane
molecule from Pre-ALP cells. Expression cloning of Pre-ALP cDNA showed that
M27 recognizes carboxypeptidase M (CPM), a cell- surface, zinc-dependent
protease known to cleave off basic C-terminal amino acids from peptide
hormones. Using M27 antibody, CPM was detected only at discrete B
lymphocyte developmental stages, namely on committed precursors and on
germinal center cells. CPM was also expressed on mature T cells, mainly
after activation. These results provide the first description of a
carboxy-peptidase on lymphoid cells. In addition, CPM was found on
granulocytes and monocytes, but not on their progenitors. Strikingly, CPM
was present only on CD38+ cells, irrespective of lineage affiliation. Of
interest, CPM displayed a largely overlapping distribution with the CD10
and CD13 peptidases, with which it shares common substrates (enkephalins,
bradykinin). Collectively, the present data show a previously unrecognized
distribution pattern of CPM on lymphoid and myeloid cells and suggest that
CPM may cooperate with CD10 and CD13 to regulate biologic activity of
peptide hormones on leukocytes.
Volume 86,
Issue 3,
pp. 1098-1105,
08/01/1995
Copyright © 1995 by The American Society of Hematology
