Molecular identification of IgE-dependent histamine-releasing factor as a B cell growth factor.
The culture supernatants of LK1 cells, murine erythroleukemia cells, showed B cell-stimulating activity. Purification and NH(2)-terminal sequence analysis revealed that one of the candidates was murine IgE-dependent histamine-releasing factor (IgE-HRF), which is known to induce histamine from basophils. Recombinant IgE-HRF (rHRF) obtained from Escherichia coli- or 293-transformed embryonal kidney cells was tested for B cell-stimulating activity. Both rHRFs stimulated B cell proliferation in a dose-dependent manner. However, boiling or anti-HRF Ab abolished the B cell stimulatory effects of rHRF. Recombinant HRF showed strong synergistic effects with IL-2, IL-4, and IL-5 for B cell activation, with maximal activity in the presence of anti-CD40 AB: Recombinant HRF increased MHC class II expression of B cells. It also increased Ig production from B cells. Treatment with polymyxin B, a neutralizing peptide antibiotic of LPS, did not reduce the activity of rHRF. In addition, FACS analysis using PE-conjugated rHRF showed that HRF bound to B cells. Recombinant HRF up-regulated the expression of IL-1 and IL-6 in B cells. In vivo administration of rHRF or the cDNA for rHRF increased total and Ag-specific Ig synthesis. Taken together, these results indicate that HRF stimulates B cell activation and function.
Kang
H S
HS
Laboratory of Immunology, Korea Research Institute of Bioscience and Biotechnology, Eoun-Dong 52, Yusong, Taejon 305-333, Republic of Korea.
Lee
M J
MJ
Song
H
H
Han
S H
SH
Kim
Y M
YM
Im
J Y
JY
Choi
I
I
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D014408:Biomarkers, Tumor; D002455:Cell Division / Q000276:immunology; D002474:Cell-Free System / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D006133:Growth Substances / Q000008:administration & dosage / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D006632:Histamine / Q000378:metabolism*; D006801:Humans; D007073:Immunoglobulin E / Q000502:physiology*; D007136:Immunoglobulins / Q000096:biosynthesis; D007273:Injections, Intramuscular; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008222:Lymphokines / Q000008:administration & dosage / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000276:immunology; D000090324:Tumor Protein, Translationally-Controlled 1
D014408:Biomarkers, Tumor; D016207:Cytokines; D006133:Growth Substances; D007136:Immunoglobulins; D008222:Lymphokines; D000090324:Tumor Protein, Translationally-Controlled 1; D007073:Immunoglobulin E; D006632:Histamine