Presence of estrogen‐binding sites on macrophage‐like synoviocytes and cd8+, cd29+, cd45ro+ t lymphocytes in normal and rheumatoid synovium

Abstract

Objective. To study the presence of estrogenbinding sites (EBS) in the synovial tissues of male and female patients with rheumatoid arthritis (RA) and in age-and sex-matched healthy controls.Methods. Both type 1 (high affinity, low binding capacity) and type 2 (reduced affinity, higher binding capacity) EBS were investigated in both soluble and nuclear fractions of homogenized synovial tissue sam- ples by a dextran-coated charcoal method. To determine what type of synovial cell was positive for EBS, cryosections of synovial tissues were immunostained with a specific monoclonal anti-estrogen receptor antibody (anti-ER MAb) using both immunofluorescence and immunoperoxidase techniques. Double immunostaining with the anti-ER MAb and with specific MAb to detect different macrophage antigens (Ber-MAC3, MAC387, CD68) and CDS+ T cell subsets (CD29+, CD45RO+ and CD29-, CD45RO-) was performed.Results. Higher affinity EBS were found mostly in nuclear cell fractions of either RA or control synovial tissues (28 of the 33). These EBS were present to a lesser extent in soluble cell fractions (11 of the 33). Immunostaining showed the estrogen receptor-positive cells to be the macrophage-like synoviocytes and the CD8+, CD29+ T cells both in RA and in control synovial tissues. Higher nuclear content of EBS was consistent with more intense nuclear staining of synoviocytes and T cells.Conclusion. It is conceivable that the immunomodulatory activity exerted by estrogens is at least partly mediated through their interaction with EBS that are present on macrophage-like synoviocytes, functioning as antigen-processing and antigen-presenting cells, and on antigen-experienced (memory) CDS+ T lymphocytes (CD29+, CD45RO+).Females have better humoral immune responses and are more susceptible to autoimmune diseases than males. This sex-related dimorphism in immune capabilities is thought to be related to the physiologic effects of the sex hormones on the immune system (1-6). Generally, estrogens have immunostimulatory effects, whereas androgens are immunosup-

Phorbol diester 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) up‐regulates the expression of estrogen receptors in human THP‐1 leukemia cells

“…The monocyte/phagocyte system has been reported to be exquisitely sensitive to estrogens, supporting the view that gonadal steroids are primary regulators of various sides of the immune response [Grossman, 1989]. The presence of ER in different immune cell types has been repeatedly reported by others and our own group [Cohen et al, 1983;Danel et al, 1983;Carbone et al, 1986;Cutolo et al, 1993Cutolo et al, , 1996. In addition, estradiol has been involved in the regulation of macrophage activity, especially in the bone [Oursler et al, 1991].…”

“…ER content and status of THP-1 cells was determined by means of LBA, using a modi®ca-tion of a previously described method [Castagnetta et al, 1983[Castagnetta et al, , 1987bCutolo et al, 1993Cutolo et al, , 1996. The cell pellets were washed twice in icecold PBS-A, resuspended in 4 ml of HED buffer (Hepes 10 mM, EDTA 1.5 mM, Dithiothreitol 0.5 mM, pH 7.4) and gently te¯on-glass homogenized for 2 Â 10 s bursts at a setting of 600±800 rpm on a Potter S cooling system homogenizer (B.Braun Biotech Int.…”

“…In particular, it has been reported that estrogens positively affect IL-1b and TNFa mRNA expression in TPA-stimulated THP-1 cells [Shanker et al, 1994a,b]. Estrogen receptors (ER) have been identi®ed in immune cells, such as thymocytes , CD8 T lymphocytes [Cohen et al, 1983], mononuclear cells [Carbone et al, 1986], and recently, synovial macrophages [Cutolo et al, 1993[Cutolo et al, , 1996.…”

17β‐estradiol regulates cytokine release through modulation of CD16 expression in monocytes and monocyte‐derived macrophages

“…Macrophages are the major immune cell present within the synovial tissues and are recruited in high numbers in RA, suggesting that a majority of IL-1 and TNF␣ release within the joint is from this cell type (17). Subsequent to and building upon these studies, the nuclear receptor estrogen receptor ␤ (ER␤) was detected in macrophages, revealing a mechanism by which estrogen can act to effect molecular signals within the cells (18,19). Investigators in our laboratory have detected the presence of ER␣ and ER␤ transcripts and ER␤ protein in primary macrophages and have found that removal of estrogen did not have a dramatic effect on the amount of ER protein present, suggesting that estrogen does not regulate its own receptor in monocyte-derived macrophages (20).…”

Androgen metabolism and inhibition of interleukin‐1 synthesis in primary cultured human synovial macrophages

“…-11 However, it is only recently that androgen and oestrogen receptors have been detected in synovial macrophages (mCs) of normal and rheumatoid synovial tissues, by immunostaining of cryosections and by biochemical characterization in homogenized tissues. 12,13 The presence of androgen receptors on mCs induced us to analyse the metabolic pathway for androgens.…”