Enhanced complement sensitivity of NK-T cells in murine thymus and spleen associated with presence of serum immunoglobulin.
In vitro treatment of thymocytes and splenocytes with rabbit complement (C') alone induced significant reductions in the proportion of NK-T cells in murine system. The reduction appeared to be prominent in the thymic NK-T cells compared to that in splenic NK-T cells. No reductions were detected in other populations, such as T, B and NK cells. Thus, NK-T cells lineage-specifically showed the enhanced C' sensitivity. However, NK-T cells in T cell receptor (TCR) transgenic mice of RAG-/- background that lack B cells and antibodies exhibited no C' sensitivity. On the other hand those from the same TCR transgenic mice of RAG intact background that have a normal population of B cells and antibodies showed the C' sensitivity similar to that in normal mice. These findings suggest that the enhanced C' sensitivity observed in the NK-T cell population is associated with the NK-T specific autoantibodies. Indeed, we found that a subset of NK-T cells in the thymus bound mouse immunoglobulins. Similar observations were obtained with several strains of lupus model mice, some of which show a decrease of NK-T cells with aging. Possible roles of the enhanced C' sensitivity of NK-T cells in pathophysiological conditions in various mouse strains including lupus models are discussed.
Onoé
Kazuyuki
K
Division of Immunobiology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.
Iwabuchi
Kazuya
K
Iwabuchi
Chikako
C
Tone
Saori
S
Konishi
Jun
J
Kawakami
Yoshikazu
Y
Nishimura
Masaharu
M
Onoé
Kazunori
K
D000818:Animals; D003165:Complement System Proteins / Q000494:pharmacology*; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology; D007136:Immunoglobulins / Q000097:blood; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D008814:Mice, Inbred NZB; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011817:Rabbits; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology
D018398:Homeodomain Proteins; D007136:Immunoglobulins; D016693:Receptors, Antigen, T-Cell, alpha-beta; C064658:RAG-1 protein; D003165:Complement System Proteins