Structure and Function of Fc Receptors for Ige (FcɛR) on Monocytes and Macrophages

High IgE responder rats were sensitized intraperitoneally with alum-adsorbed ovalbumin and Bordetella pertussis organisms. At day 0, 7, 14, 21 and 28 following sensitization the peritoneal cells were harvested and further processed for light and immunoelectron microscopical investigations using a specific anti-rat IgE immunogold sandwich method. The results obtained show that the number of peritoneal mast cells increase significantly during the course of sensitization. There is a time-dependent increase in the amount of immunogold particles on mast cell surfaces together with a shift of particle distribution towards the surface folds. Sensitized mast cells exhibit altered releasability as is indicated by slightly degranulated cells at day 21 and day 28 postsensitization. Additionally, about 25% of small lymphocytes which had entered the peritoneal cavity between day 7 and day 14 are heavily stained with the immunogold complex between day 14 and day 28 postsensitization. This is not so for macrophages (≤0.2% positive cells) nor for eosinophils which do not show any staining activity at all despite they are present in high numbers.

Section: Discussioncontrasting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Time-Course of IgE Binding to Rat Peritoneal Cells after Sensitization with Alum-Adsorbed Ovalbumin and Bordetella pertussis

Behrendt¹

1987

“…However, our experiments were performed in the absence of immunoglobulins: (i) no serum was added to the cultures and (ii) the putative cytophilic antibod ies have been certainly eliminated since the cells were washed many times (the association constant of IgG or IgE to the Fc receptors present on macrophages be ing about 106-107 M] [29,30], the washing steps led to the dissociation of immunoglobulins from the macro phage surface).…”

Section: Discussionmentioning

confidence: 99%

Presence of IL 1 Activity in the Supernatant of Human Monocytes Challenged with Purified Allergenic Constituents

Cavaillon

Dandeu

Mécheri

et al. 1984

Purified allergenic constituents from Dermatophagoides farinae mite (Df 11 and Df 6) and from orchard grass (Dactylis glomerata) pollen (F 34) are able to trigger, in the absence of IgE and IgG antibodies, human adherent cells, leading to the secretion of interleukin 1, (IL 1). This secretion was observed with adherent peripheral blood mononuclear cells from normal donors as well as from atopic patients. The IL 1 activity was evaluated by the mice thymocyte mitogenesis in the presence of suboptimal doses of Con A. The secretion of IL 1 by adherent cells was not affected by a cytotoxic treatment with OKT3 monoclonal antibody in the presence of complement, implying a direct action of allergenic fractions, on monocytes, and not through a T-cell pathway. The challenge of human monocytes with allergens in the presence of indomethacin led to culture supernatants for which a higher ³H-thymidine incorporation by mice thymocytes was detected; thus, purified allergens could also trigger the secretion of prostaglandins by human monocytes.

“…In these situations an increase in the percentage of lymphocyte or mono cytes forming IgE rosettes was reported [22][23][24], An enhancement of IgE receptors on macrophages from rats infected with Nippostrongylus hrasiliensis was de scribed [25], The induction of the Fc;. receptors on these cell populations by IgE was studied [23,25,26]. In this report, the relationship between IgE and im mune macrophages during the course of Schistosoma mansoni was examined.…”

Section: Introductionmentioning

confidence: 99%

“…In para site [18][19][20] or in allergic [21,22] diseases elevated serum IgE levels were observed. In these situations an increase in the percentage of lymphocyte or mono cytes forming IgE rosettes was reported [22][23][24], An enhancement of IgE receptors on macrophages from rats infected with Nippostrongylus hrasiliensis was de scribed [25], The induction of the Fc;. receptors on these cell populations by IgE was studied [23,25,26].…”

Section: Introductionmentioning

confidence: 99%

Variation in the Expression of Macrophage Fcε Receptors in Relation to Experimental Rat Schistosome Infection

Pestel¹,

Joseph²,

Dessaint³

et al. 1988

The relationship between IgE and rat peritoneal macrophages during the course of Schistosoma mansoni infection was examined. Immune macrophages exhibited an IgE-dependent schistosomulicidal activity mainly between the 5th and the 7th weeks. At this period the percentages of anti-lgE rosettes whose variations appeared consecutive to the variations in the serum IgE level were higher. Following incubation in a serum-free medium immune macrophages could release membrane-associated IgE, to a certain extent, and consequently formed rosettes with IgE-coated erythrocytes, indicating the existence of Fc_ε receptors. Thus, in terms of rosettes, their number varied in the course of the disease. In fact IgE-rich serum (i.e. at day 42) as IgE molecules could induce this macrophage Fc_ε receptor. Moreover when transferred to syngeneic rats in associaton with parasite-specific IgE Fc_ε R₂⁺ macrophages led to some protection against challenge infection. All the data reported here emphasize the determining role of macrophages and IgE in immunity to schistosomiasis.