Human and murine lymphocyte neurotrophin expression is confined to B cells

• Published in: Journal of neuroscience research Vol. 77; no. 5; pp. 709 - 717
• Main Authors: Edling, Andrea E., Nanavati, Tania, Johnson, Justin M., Tuohy, Vincent K.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.09.2004
• Subjects: Animals; autoimmunity; B cells; B-Lymphocytes - metabolism; Blotting, Southern - methods; Brain-Derived Neurotrophic Factor - metabolism; EAE/MS; Female; Gene Expression Regulation - physiology; Humans; Male; Membrane Glycoproteins - metabolism; Mice; Mice, Inbred Strains; Myelin Proteolipid Protein - immunology; Nerve Growth Factor - metabolism; Nerve Growth Factors - genetics; Nerve Growth Factors - metabolism; Neurotrophin 3 - metabolism; neurotrophins; Peptide Fragments - metabolism; Protein-Tyrosine Kinases - metabolism; Receptor, trkB - metabolism; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - biosynthesis; Sequence Analysis, DNA - methods; T cells
• ISSN: 0360-4012; 1097-4547
• DOI: 10.1002/jnr.20176

Recent reports indicate that autoreactive T cells may produce neurotrophic factors capable of mediating repair and regeneration of damaged neurons. By using semiquantitative RT‐PCR, we examined gene expression of nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), neurotrophin‐3 (NT‐3), and the trkB BDNF receptor in autoreactive T cells from SWXJ mice immunized with the p104–117 encephalitogen of myelin proteolipid protein (PLP 104–117). We observed antigen‐inducible expression of NGF and BDNF, but not NT‐3 and trkB, in lymph node cells activated with PLP 104–117. To determine which leukocyte subpopulation expressed neurotrophins, CD4+, CD8+, B220+, CD11b+, and NK1.1+ cells were purified from activated primary cultures, and their mRNAs were analyzed. Neurotrophin expression was also measured in CD3+ T cells purified from mouse CNS during acute onset of experimental autoimmune encephalomyelitis as well as in resting and activated human T cells and B cells purified from peripheral blood of normal subjects. In all cases, we found that neurotrophin expression was confined exclusively to B cells (B220+) in both mouse and human. CD3+, CD4+, and CD8+ T cells as well as NK1.1+ cells and CD11b+ monocytes and macrophages did not express any detectable BDNF, NGF, NT‐3, or trkB under any conditions. Our data indicate that B cells rather than T cells are the predominant if not the only source of leukocyte‐derived neurotrophins and as such may provide “protective autoimmunity” in repair and regeneration of the injured nervous system. © 2004 Wiley‐Liss, Inc.