B-cell reconstitution and xenoreactive anti-pig natural antibody production in severe combined immunodeficient mice reconstituted with immunocompetent B cells from varying sources.
BACKGROUND
Little is known about the B-cell subsets that produce xenoreactive natural antibodies (NAb). This study was undertaken to investigate the potential role of varying B-cell populations in anti-pig NAb production in mice.


METHODS
Severe combined immunodeficient (scid) mice were reconstituted with bone marrow or splenic or peritoneal B cells from immunocompetent mice. B-cell reconstitution and anti-pig NAb were evaluated by flow cytometric analysis.


RESULTS
Adult marrow failed to reconstitute normal numbers of CD5+ B1a cells, but fully reconstituted CD5- Mac1- B2 and CD5- Mac1+ B1b cell populations in scid mice. Recipients of peritoneal B cells showed poor reconstitution of B2 cells, and an overshoot of B1 cells in the peritoneal cavity. Although B2 cells predominate in the adult spleen, splenic B cells from immunocompetent mice preferentially reconstituted B cells, including B1 cells, in the peritoneal cavity, but did not reconstitute splenic B2 cells. Therefore, neither adult marrow, splenocytes nor peritoneal cells can fully reconstitute scid mice with all B-cell subpopulations. Nevertheless, serum anti-pig NAb in marrow-reconstituted mice recovered to normal levels by 3 weeks, and were maintained for at least 30 weeks. Serum NAb in scid mice receiving peritoneal B cells reached normal levels by 4-7 weeks after transfer. However, NAb in sera of scid mice receiving splenic B cells took longer (>25 weeks) to reach normal levels.


CONCLUSIONS
These results indicate that adult marrow-derived B cells can efficiently produce anti-pig NAb, and that peritoneal B cells have greater NAb-producing ability than splenic B cells or their immediate progeny.
Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston 02129, USA.
Y G
YG
Yang
E
E
deGoma
R
R
Barth
J J
JJ
Sergio
M
M
Sykes
D000818:Animals; D000917:Antibody Formation / Q000502:physiology; D015478:Antigens, Heterophile / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology*; D016026:Bone Marrow Transplantation; D008212:Lymphocyte Depletion; D017710:Lymphocyte Transfusion; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID / Q000502:physiology*; D010537:Peritoneum / Q000166:cytology; D013154:Spleen / Q000166:cytology; D013552:Swine / Q000276:immunology*
D015478:Antigens, Heterophile