RUDOLF L BAER

Recent reports show that transforming growth factor (TGF)-beta exerts a variety of immunosuppressive activities. The present study focuses on the effects of TGF-beta 1 on expression of Ia antigen by Langerhans cells. Although TGF-beta 1, in concentrations from 0.001 to 100 micrograms/ml, has no effect on constitutive expression of Ia antigen on these cells, the in vitro up-regulation of Ia antigen on the surface of LC by interleukin (IL)-1, tumor necrosis factor-alpha, interferon-gamma, ...

In order to further define the role of Langerhans cells in contact allergic reactions, passive transfer studies were done in guinea pigs using 2,4-dinitro-1-chlorobenzene (DNCB)-sensitive donor cells. Langerhans cells were found in the lumen of dermal vessels resembling lymphatics at 2, 3, 15, and 48 hr after DNCB challenge. In contrast to the previously reported findings in actively sensitized guinea pigs, the changes involving Langerhans cells in passively sensitized guinea pigs were ...

Ferritin-challenged skin sites and draining lymph nodes were studied in normal guinea pigs and in guinea pigs which had been passively sensitized to ferritin or peroxidase by lymphoid cell transfer to ascertain whether Langerhans cells can bind antigen in skin and carry it to lymph nodes. After intradermal challenge with amounts of ferritin as small at 5 μg, ferritin-containing Langerhans cells were seen by electron microscopy in the marginal sinus and cortex of draining lymph nodes in ...

Evidence in favor of a role for Langerhans cells in contact allergic hypersensitivity reactions has been reviewed. This includes mononuclear cell to Langerhans cell apposition and damage to some Langerhans cells at sites of specific challenge to a variety of contact allergens. Such apposition occurs in actively sensitized patients and guinea pigs and in passively sensitized guinea pigs. In addition, in passively sensitized guinea pigs Langerhans cells circulate in dermal vessels ...

We investigated the possible role of a defect in antigen-presenting cells in the acquired immunodeficiency syndrome (AIDS), by enumeration of Langerhans' cells, the epidermal antigen-presenting cells. These cells were stained for the characteristic markers, surface Ia antigen and surface ATPase activity. A significant reduction was observed in the number of stained cells per square millimeter of body-surface area in 24 patients with AIDS and either opportunistic infections (Ia, 258 +/- ...

We have investigated the effect of ultraviolet-B (UVB) irradiation on the density of epidermal ATPase-positive Langerhans cells, and the modulation of this effect by indomethacin (IND). Depilated backs of albino guinea pigs were exposed to varying doses of UVB (10-550 mJ/cm2). Skin biopsies were taken serially. There was an UVB dose-dependent decrease in the density of dendritic epidermal Langerhans cells, as identified by their membrane ATPase activity. This was accompanied by thinning ...

Five patients with photoallergic contact dermatitis due to halogenated salicylanilides and chemically related antimicrobial agents are presented. Cross-photosensitivity is demonstrated between tetrachlorosalicylanilide, tribromosalicylanilide, and bithionol, but not with hexachlorophene. Ultraviolet light in the range of 3,200-4,500 Angstrom units is required for initiation of these photoallergic reactions. Histologically photoallergic contact dermatitis is identical with allergic ...

Skin of normal, cobra venom extract-treated, and C4-deficient guinea pigs was injected with ferritin-antiferritin or with peroxidase-antiperoxidase immune complexes. Skin and draining lymph nodes were studied to compare the phagocytosis of these immune complexes by Langerhans cells (LC) and by macrophages. When complement was present, immune complexes were damaging to LC, and uptake of the immune complexes, although present, was limited. When components of complement were absent or ...

The effects of topical and systemic administration of various glucocorticoids on the density of epidermal Langerhans cells (LC) were studied in guinea pigs. Glucocorticoids, such as betamethasone dipropionate and valerate, caused a marked decrease in LC demonstrable by staining for cell membrane ATPase activity and Ia antigens. By electronmicroscopy, LC also showed morphologic alterations. The observed decrements in LC density correlated with the concentration and known vasoconstrictive ...

Following incubation of murine epidermis in medium containing either interleukin-2 or interleukin-6, there is significant upregulation in the density of Ia+ epidermal Langerhans cells (to 159% and 175% of control, respectively). This cytokine-induced upregulation is abrogated by either rabbit or human IgG due to triggering of Fc gamma receptors. In contrast, human IgA does not inhibit the effect of interleukin-2 or interleukin-6. Using different isotypes of murine IgG, we have ...

The effectiveness of orally administered triamcinolone in 60% of the cases treated was first reported by Shelley and colleagues1 in a series of 60 patients with psoriasis. Of 21 of these patients who had skin tests in a psoriatic lesion with a 1% suspension of triamcinolone, 11 showed a zone of clearing at the injection site. Subsequently one of us (R. L. B.) with Cohen2 demonstrated that triamcinolone in suspension injected intradermally produced larger zones of clearing in psoriatic ...

A patient with known urticarial penicillin allergy and an immediate positive skin test to penicilloyl-polylysine (PPL) had subacute bacterial endocarditis which necessitated high daily intravenous doses of penicillin G (PG). Changes occurred during treatment with penicillin in the titers of both penicilloyl-specific skin-sensitizing antibodies and IgG antibodies. An initial drop of skin-sensitizing and IgG antibodies was followed by a rise in titer of these antibodies. Two mechanisms are ...

The effect of 750 rads of gamma radiation on the rate of return of epidermal Langerhans cells (LC) following suppressive doses of topical glucorticoids was studied in guinea pigs. Gamma radiation alone had no effect on the LC as assessed by staining for cell membrane ATPase activity and Ia antigen. It did, however, delay the expected return of Ia but not ATPase surface markers on the LC after perturbation with glucocorticoids. The delayed return of surface Ia antigen is possibly related ...