Administration of IL-7 to normal mice stimulates B-lymphopoiesis and peripheral lymphadenopathy.
Normal mice were injected with IL-7 (500 ng, twice daily) for various periods of time up to 6 days and the cellularity and phenotypic composition of the thymus, spleen, lymph node, and bone marrow was assessed. After 6 days of treatment, significant increases in the cellularity of the spleen, lymph node, and bone marrow were observed which returned to the normal range within 6 days after cessation of treatment. After 3 days of IL-7 treatment, increased numbers of B220+/surface(s) IgM- bone marrow cells were observed. After 6 days of treatment, these numbers were still further increased and a significant population of B220+/sIgM- cells were observed in the spleen. The numbers of c mu+/sIgM- cells were also increased in the IL-7-treated mice. Analysis of the expression of B220 and BP-1 on the sIgM- bone marrow cells revealed that the B220+/BP-1+ population was dramatically increased after IL-7 treatment and the size of the B220+/BP-1- population did not differ from control mice. The pre-B cell numbers declined rapidly after the cessation of IL-7 treatment. After 6 days of IL-7 treatment, a twofold increase in the number of B cells in the spleen and lymph node was observed. The B cell numbers declined to normal values within 6 days after the cessation of IL-7 administration. In the spleens of the IL-7-treated mice, there was a significant increase in the number of B cells with an immature phenotype (e.g., sIgMhi/sIgDlo, decreased levels of Ia and FcR expression). The numbers of CD8+ and CD4+ T cells were also increased in the lymph node and spleen of the IL-7-treated mice. These numbers declined to normal levels after the cessation of IL-7 treatment.
Morrissey
P J
PJ
Immunex Corporation, Seattle, WA 98101.
Conlon
P
P
Charrier
K
K
Braddy
S
S
Alpert
A
A
Williams
D
D
Namen
A E
AE
Mochizuki
D
D
D000818:Animals; D000950:Antigens, Ly / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000166:cytology; D001402:B-Lymphocytes / Q000166:cytology*; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D006410:Hematopoiesis / Q000187:drug effects*; D015851:Interleukin-7 / Q000494:pharmacology*; D017493:Leukocyte Common Antigens; D007958:Leukocyte Count; D008198:Lymph Nodes / Q000166:cytology; D008206:Lymphatic Diseases / Q000139:chemically induced*; D051379:Mice; D008810:Mice, Inbred C57BL; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D011994:Recombinant Proteins; D013154:Spleen / Q000166:cytology; D016176:T-Lymphocyte Subsets / Q000166:cytology
D000950:Antigens, Ly; D000954:Antigens, Surface; D015851:Interleukin-7; D011947:Receptors, Antigen, B-Cell; D011994:Recombinant Proteins; D017493:Leukocyte Common Antigens