Naslov
Effects of ovariectomy on bone marrow lymphocyte populations in gld mice

Autori
Grčević, Danka ; Kovačić, Nataša ; Katavić, Vedran ; Lukić, Ivan Krešimir ; Marušić, Ana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Annual Meeting of the Croatian Immunological Society / - Zagreb, 2001

Skup
Annual Meeting of the Croatian Immunological Society

Mjesto i datum
Zagreb, Hrvatska, 07.12.2001

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
lymphocytes; bone marrow; ovariectomy

Sažetak
Aim: We investigated the changes in bone marrow lymphocyte subsets after ovariectomy in B6 and gld mice. Mice homozygous for a point mutation in the extracellular domain of the Fas ligand gene produce a non-functional mutant molecule and develop generalized lymphoproliferative disorder (gld mutation) (Takahashi T et al. Cell 1994). Gld mice develop autoimmune syndromes, characterized by the formation of a broad spectrum of autoantibodies and T-lymphocyte-dominated lymphadenopathy with the accumulation of unusual CD4-CD8-Thy-1+ T-lymphocyte subsets (Reap EA et al. Clin Immunol Immunopathol 1996, Davidson WF et al. J Immunol 1991). Furthermore, other phenotypic abnormalities of splenic, bone marrow and lymph node T- and B-lymphocyte subsets have been reported in gld mice (MacDonald GC et al. J Immunol 1995, Sobel ES et al. J Immunol 1995). One of the regulator of B-lymphopoiesis is estrogen, which has been shown to be involved in the regulation of B-lymphocyte lineage differentiation, as the number of B-lymphocyte precursors increases in hypogonadal, ovariectomized or male castrate mice (Smithson G et al. J Immunol 1998, Miyaura C et al. PNAS 1997). Methods: 12 week-old female mice, either wild-type (C57BL/6, B6) or homozygous for the gld point mutation (gld) were used in all experiments. B6 or gld mice were sham-operated (Sham) or ovariectomized (Ovx), and sacrificed 3 weeks after surgery. Uteri were isolated and wet uterine weights were measured to confirm the effects of estrogen depletion. For phenotypic characterization of lymphocyte subsets we used monoclonal antibodies against different lineage and activation markers (CD3, CD4, CD8, CD11b, CD19, CD23, CD45R/B220, CD71) labeled with different fluorescent dyes. Fluorescence intensity was measured using FACSCaliburä flow cytometer (Becton Dickinson, San Jose, CA, USA), with a total of 5x104 events analyzed per sample. Results: In the spleen and lymph nodes of Sham gld mice we found a decreased percentage of CD4+ or CD8+ T lymphocytes by 20-30%, whereas there was a 4- or 2.5-fold increase in the percentage of CD3+B220+ double-positive subset compared with Sham B6 mice, respectively. In the marrow, gld mice had relatively more B220low than B220high B-lymphocytes than B6 mice, and tended to have more B220+CD19- B-lymphocytes. We further investigated bone marrow cells, since the marrow is the site of the estrogen effect on B-lymphopoiesis and bone loss. Ovx increased the percentage of the B220+ subset in both B6 and gld mice (from 26.4% to 40.3% in B6, and from 25.7% to 39.0% in gld mice). Consequently, the percentage of the CD11b+ subset decreased by 10% in both groups of Ovx mice. Also, it seems that Ovx increased the percentage of CD23+B220+ double-positive mature B-lymphocytes 2-fold in B6 but not in gld mice. Conclusions: B6 and gld mice differ in lymphocyte subsets. In spleen and lymph nodes gld mice had an increase in unusual CD3+B220+ T lymphocytes, whereas they had a decrease in CD4+ or CD8+ single-positive T lymphocytes. In the bone marrow, Ovx increased the B220+ B-lymphocyte subset in both B6 and gld mice, without changes in T lymphocyte subsets. Our results suggest that gld mice have relatively larger number of less mature B-lymphocytes in the marrow compared to B6 mice, and that Ovx causes an increase predominantly in that B-lymphocyte subset.

Izvorni jezik
Engleski

Znanstvena područja
Farmacija

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