T-cell-derived factor B151-TRF1/IL-5 activates blastoid cells among unprimed B cells to induce a polyclonal differentiation into immunoglobulin M-secreting cells.
Two distinct murine B-cell differentiation factors, designated B151-TRF1 and B151-TRF2, were described originally as B151K12 T-cell hybridoma-derived lymphokines that induce immunoglobulin (Ig) secretion by antigen-activated B cells and unstimulated B cells, respectively. In the present study, we found that a highly purified B151-TRF1 fraction prepared by reversed-phase high-performance liquid chromatography (RP-HPLC) also has the ability to cause a polyclonal differentiation of unstimulated B cells into IgM-secreting cells in the apparent absence of co-stimulant. The activity of the B151-TRF1 fraction but not the B151-TRF2 fraction on unstimulated B cells was markedly inhibited by addition of a monoclonal antibody (mAb) specific for the B151-TRF1/IL-5 to the culture. To determine whether B151-TRF1/IL-5 and B151-TRF2 act on distinct populations among unstimulated B cells, the responsiveness of neonatal B cells and adult B cells that had been fractionated by Percoll density gradient centrifugation was assessed. B151-TRF1/IL-5 predominantly acted on lower density B cells, which appeared around 3 weeks after birth in the spleen. In contrast, B151-TRF2 could activate both lower and higher density B cells almost equally and B151-TRF2-responsive B cells were already present by 1 week of age. Thus, these results suggest that B151-TRF1/IL-5 and B151-TRF2 act on distinct subpopulations among antigen-unprimed normal B cells to induce IgM-secreting cells.
Murakami
S
S
Department of Oncogenesis, Osaka University Medical School, Japan.
Ono
S
S
Harada
N
N
Hara
Y
Y
Katoh
Y
Y
Dobashi
K
K
Takatsu
K
K
Hamaoka
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism*; D015847:Interleukin-4; D015848:Interleukin-5; D007378:Interleukins / Q000494:pharmacology*; D008213:Lymphocyte Activation; D051379:Mice
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D007075:Immunoglobulin M; D015848:Interleukin-5; D007378:Interleukins; D015847:Interleukin-4