Engrafted human T and B lymphocytes form mixed follicles in lymphoid organs of human/mouse and human/rat radiation chimera.
BACKGROUND
We recently described a new approach that enables the generation of human/mouse chimera by adoptive transfer of human peripheral blood mononuclear cells into lethally irradiated normal strains of mice or rats, radioprotected with bone marrow from donors with severe combined immune deficiency. In such human/mouse chimera, a marked humoral response to recall antigens, as well as a significant primary response to keyhole limpet hemocyanin, has been generated.


METHODS
In the present study, the organ distribution of the engrafted human cells in the human/mouse and human/rat chimera was investigated by immunohistochemistry.


RESULTS
Our results show that the T cells seem to be distributed throughout the reticular endothelial system, almost behaving like particles without any homing specificity. The B cells, however, can barely be found in internal organs, such as the liver or the pancreas, and are concentrated in the secondary lymphoid system (e.g., spleen, lymph node, and nonencapsulated lymphoid tissue). The B cells, together with the engrafted human T cells, form mixed lymphoid follicles.


CONCLUSIONS
The different homing patterns exhibited by the T and B lymphocytes indicate that the homing receptors on human B cells might be cross-reactive with their mouse counterparts, in contrast to the human T cells, which seem to be unable to interact with the mouse homing receptors. The presence of human B and T lymphocytes in close proximity to each other in the lymphoid tissues is in accordance with the ability of human/BALB radiation chimera to mount significant primary human antibody responses.
Burakova
T
T
Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.
Marcus
H
H
Canaan
A
A
Dekel
B
B
Shezen
E
E
David
M
M
Lubin
I
I
Segal
H
H
Yair
R
R
D019264:Adoptive Transfer; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000637:transplantation*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007143:Immunoglobulin Heavy Chains / Q000032:analysis; D007147:Immunoglobulin Light Chains / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000166:cytology; D008221:Lymphoid Tissue / Q000166:cytology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D011828:Radiation Chimera; D051381:Rats; D011917:Rats, Inbred Lew; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D013154:Spleen / Q000166:cytology; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000276:immunology / Q000637:transplantation*; D013997:Time Factors
D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell