Characterization of facteur thymique sérique (FTS) in the thymus. I. Fixation of anti-FTS antibodies on thymic reticulo-epithelial cells

Facteur thymique sérique (FTS) is a circulating nonapeptide inducing T cell differentiation. Its strict thymus dependency, already shown by its disappearance after thymectomy and its presence in thymus extracts, was confirmed using indirect immunofluorescence or immunoperoxidase by the binding to reticulo-epithelial cells of an antibody produced against synthetic FTS. The specificity of the reaction was demonstrated by the inhibition of binding observed after preincubating the anti-FTS antibody with synthetic FTS.

Cytoplasmic localization of FTS (facteur thymique sérique) in thymic epithelial cells. An immunoelectronmicroscopical study

This study was concerned with the localization of the facteur thymique sérique (FTS) by immunoelectronmicroscopy in cultured thymic epithelial cells. The FTS antibodies labelled differently sized cytoplasmic vacuoles containing a substance of variable density. This substance occurs occasionally in crystalline structures which reacted strongly with purified FTS antibodies. On the ultrastructural level the FTS-positive cells were demonstrated to fix specifically keratin antibodies and to contain tonofilaments. Some of these cells originated from the thymic medulla proved by the presence of microvilli-forming cytoplasmic vacuoles. The existence of FTS-positive crystalline inclusions confirmed the hypothesis of a storage process in the cytoplasm of thymic epithelial cells in vitro or in pathological conditions.

Binding specificity of guinea pig anti-alpha-keratin polypeptide sera on human keratinocytes: comparison of their receptors with those of human epidermal cytoplasmic antibodies

Experimental anti-keratin polypeptide sera (KPS) which were prepared by immunizing guinea pigs with the P1 polypeptide (molecular weight: 67 0000 dalton) of alpha-keratin of normal human stratum corneum, were shown to react in immunofluorescence only to cell cytoplasmic antigen of the upper layers of the epidermis. No staining was detected in the basal layer. An immunolabeling performed on free epidermal cells obtained after trypsinization demonstrated by electron microscopy that receptors for KPS were tonofilaments. Minor proportions of negative cells containing tonofilaments and numerous melanosomes detected might correspond to the basal cells. An IF pattern similar to that seen with KPS was observed with some human epidermal cytoplasmic sera (ECS). However, reciprocal blocking tests performed on both rabbit lip and normal human skin with the different sera showed no inhibition. No cross-reaction was detected by immunodiffusion test between whole purified alpha-keratin and human ECS. In electron microscopy, the receptors for ECS appeared not to be keratin-like, but were located on a granular part of the peripheral keratinocyte cytoplasm. These findings confirmed two steps (basal and malphighian layers) in epidermal differentiation defined by antigenic markers and especially by the alpha-keratin component of MW 67 000 d present in normal stratum corneum.

[Study of normal and pathological keratinization using anti-keratin polypeptide sera (author's transl)]

Anti-keratin polypeptide sera were obtained against the different bands of polyacrylamide gel electrophoresis of fibrous proteins of stratum corneum derived from normal human epidermis. The sera were tested by indirect immunofluorescence of immunoperoxidase techniques. It was demonstrated that antibodies against P1 and P2 polypeptides, of MW 67,000 and 62,000 daltons respectively, were directed towards cytoplasmic antigens of keratinocytes of the upper Malpighian layers, while no labelling could be detected in the basal cell layer. Anti-P3 polypeptide sera and the anti-whole keratin serum labelled the whole epidermis, including the basal cell layer. Ultrastructural immuno-labelling performed on free epidermal cells obtained after trypsinization demonstrated that receptors for anti-P1 polypeptide sera were tonofilaments. These results showed that some keratin components (P1 and P2 polypeptides) might be absent in basal cell tonofilaments. This in in favour of various differentiation stages of the keratinizing cells. Keratin polypeptide 1 could be a useful marker of keratinization. According to preliminary studies, the expression of this keratin antigens was markedly disturbed in tumors such as basal and squamous cell carcinoma, in warts and in ichthyosis.

Cutaneous hypermelanosis and intramelanotic lipid droplets

Intramelanocytic lipid droplets have been observed in 12 patients with different types of hypermelanosis of the skin. These include drug-induced hypermelanosis, hypermelanosis secondary to use of physical agents, hypermelanotic morphea, generalized scleroderma with diffuse hypermelanosis, a hyperkeratotic tumor in xeroderma pigmentosum, aberrant mongolian spot, and methoxsalen-ultraviolet-A-induced hypermelanosis. Lipid storage was selectively observed in melanocytes. Most of the melanocytes with lipid vacuoles showed ultrastructural signs of hyperactive melanosome synthesis and certain cytoplasmic abnormalities such as melanosomal autophagic vacuole formation and mitochondrial alterations. The importance and the origin of the lipid droplets remain unclear.

Specific anti-hairy cell and anti-B cell antisera: characterization of surface antigens and origin of hairy cells

Hairy cells obtained from nine patients with hairy cell leukaemia were found to be sensitive to a heterologous anti-human B lymphocyte serum using a cytotoxicity assay and the ultrastructural characterization after immunoperoxydase labelling. This antiserum raised in the rabbit and rendered specific by extensive absorptions with human immunoglobulins, erythrocytes, thymocytes and monocytes, reacted with normal and pathological B lymphocytes but not with monocytes, as demonstrated by ultrastructural studies. In addition, a heterologous anti-hairy cell serum was prepared and absorbed with erythrocytes, thymocytes and monocytes. The in vitro properties of this antiserum were identical to those of the anti-human B cell serum in the various assays: cytotoxicity, rosette inhibition and ultrastructural characterization. These results demonstrate that hairy cells of the studied patients express surface antigenic specificities of the B cell population, not shared by monocytes. Further absorption of the anti-hairy cell serum with CLL cells suggested that hairy cells express other characteristic antigens in addition to the B lymphocyte antigens. HLA-DR alloantigens were also shown to be present at the surface of hairy cells. This type of immunological analysis may prove to be of help in the understanding of the differentiation abnormalities in the hairy cell leukaemia as well as in other lymphoproliferative disorders.

[Locomotion of human circulating lymphocytes methodological aspects "in vitro" (author's transl)]

Locomotor activity of lymphocytes from human peripheral blood towards the chemoattractant casein was examined in vitro in modified Boyden chambers with a single micropore filter (according to the Wilkinson's method), and in Keller's chambers with two micropore filters. Using the single filter technique, this paper reports the precise standard parameters necessary for a reproductive assay, that is a filter of 5 micron pore size (Millipore), an incubation of 5 h with 5 mg/2 ml of alpha-casein, and the counting of lymphocytes at the front of migration within the filter. The distinction between the chemotaxis (directional locomotion) and the chemokinesis (random migration) in the presence of the alpha-casein was confirmed with human circulating lymphocytes. When the results obtained with the double filter technique are compared with that of single filter, Keller's method shows no advantage over the single filter technique modified by Wilkinson. The latter appears adequate to study specific and non-specific drug-induced lymphocyte chemotaxis and chemokinesis with normal or pathological cells in man.

PUVA-induced repigmentation of vitiligo: scanning electron microscopy of hair follicles

PUVA-i-duced repigmentation of vitiligo was studied using both the split-dopa reaction and scanning electron microscopy. Proliferation of hypertrophic, Dopa-positive melanocytes were observed in the lower portion of some hair follicles, whereas other giant melanocytes were observed along the middle portion. The existence of a melanocyte reservoir in human hair follicles is postulated.

[Cutaneous histiocytosarcoma: clinical, immunohistochemical and ultrastructural aspects; difficulties of study and problems of nosology (author's transl)]

Reporting a case of cutaneous tumor of the back of recent occurrence and rapid increase in a 79-years-old woman, according to Crosti's "reticulosis", the authors discuss the following points:--the histiocytic nature of the tumor cells particularly based on immunohistochemical studies (peroxidase activity, anti-HTLA serum) and on electron microscopy with special reference to the multivesicular bodies found in their cytoplasm;--the tests for correct identification of the histiocyte (including electron microscopy, tests for HTLA and HBLA antigens, peroxidatic reaction, acid phosphatase activity, and in vivo or in vitro phagocytosis);--the out of date character of the concept of malignant "reticulosis" in the hematologica and dermatologic classifications, the recent advances in the knowledge of the nature of the so-called "reticulum" (or "reticular") cell which seems to be a distinct entity derived from the mesenchymal cell (as the fibroblast);--the clinical and evolutive characteristics of histiocytic tumors (no hematologic involvement, slow evolution, high radiosensitivity), the difficulties in defining their malignancy and, above all, in finding comparable references in the literature with complete cellular study;--the nosologic place of this affection among the group of haematodermas and in the pathology of the mononuclear phagocyte system. The generic term of cutaneous histiocytosarcoma (stage I or II) is suggested, including the whole malignant and isolated tumoral proliferations developing from the dermic histiocyte.

Quantification of HTLA-positive lymphocytes during oral photochemotherapy of psoriasis

T-lymphocyte count in the peripheral blood, based on the identification of anti-human lymphocyte antigen (HTLA) by an immunocytochemical method, was determined in 25 PUVA-treated psoriatics and in 25 controls matched by sex and age. The results demonstrate that the HTLA-positive lymphocyte counts of these two groups do not differ significantly. It is concluded that oral photochemotherapy does not induce quantitative modifications in the population of T-lymphocytes of the blood.

Ultrastructure of the human mucocutaneous end organ

The ultrastructure of the human mucocutaneous end organ is described. The corpuscle is divided into sublobular units comprising axon terminals surrounded by generally concentric lamellar processes which are derived from laminar cells whose nuclei are situated towards the periphery of the sublobules. Interlamellar substance which contains elastic tissue, collagen and coarse periodicity crossbanded structures intervenes between lamellar processes. Specialized zones of contact resembling desmosomes are found at intervals seemingly connecting adjacent lamellar processes and axons with lamellar processes. The ultrastructural features of this end organ are similar to that of the Meissner corpuscle despite minor differences of the light microscopical appearance, which supports the view that differences in sensory end organs are merely variations on a common organizational basis.

Bone bonding through bioadhesives: present status

Until recently use of adhesives was confined to cases in which glued areas could be pre-treated or at least cleaned. Thus, grease or oil contaminated surfaces could not be joined together by glueing. More recently, some adhesives have been developed which allow previous treatment of greasy surfaces to be avoided. Among these we find epoxy resins, acrylics and polyurethances. These adhesives have been used until now in various industries. We have begun a research program with these products and in aiming to design an adhesive which would enable immediate and strong bone bonding and avoid problems of metallic fixation, this study is a continuation of our previous research. Thus we tested - currently available surgical and dental adhesives - original mixtures developed in our laboratory. Mechanical assays were performed on bone samples from human femurs in different conditions : dried, cleaned, fresh, or after immersion in physiological solution. They consist essentially of tensile tests on Lhomargy and Zwick's machine wherein the stress is directed perpendicular to the interface. Variations of tensile strength (in h bar) are related to hardening time and to mixture composition. The specimens are joined together either in monolayers or in multilayers. The use of adequate catalysts ensures setting at room temperature. Torsion tests and fatigue tests are carried out concomitantly. Standardized bevel fermoral osteotomies were performed on mice with a dental saw after I.P. Nembutal anesthesia in order to test biological tolerance : - for the control group we study the evolution of bone repair after circumferential wiring - for the animals under test, bones are glued together with one of the proposed adhesives. Radiological and histological studies (using classical Azantrichrome staining after demineralization) are carried out at regular time intervals. In the control animals particular attention is paid to the time course of the formation, constitution and evolution of callus. In the test animals, we can observe callus formation, bone growth into the adhesive material and glue resorption, and look for specific antigenic phenomena. Despite expected improvements, bone glueing remains a challenge and only restricted clinical applications can be proposed.

Human B-lymphocyte heteroantigens: direct evidence for specificities not shared by monocytes

A heterologous anti-human B-lymphocyte serum was raised in the rabbit and rendered specific by extensive absorptions. After absorptions with erythrocytes and thymocytes, the antiserum was cytotoxic for an average of 18·5% of normal peripheral blood lymphocytes. Most chronic lymphatic leukaemia cells and `hairy cells' were sensitive to this antiserum but `null cells' were not. E-rosette-forming cells were insensitive to the antiserum, while EAC-rosettes and rosettes with mouse erythrocytes were partially or totally inhibited. In ultrastructural characterization studies after immunoperoxydase labelling, it was demonstrated that not only B lymphocytes, but also virtually all monocytes having phagocytized latex particles, were stained. A further absorption with monocytic cells from a patient with subacute myelomonocytic leukaemia was thus performed and the resulting antiserum was then specific for human B lymphocytes only and did not label any latex-phagocytizing monocyte. These results demonstrate that besides antigens common to monocytes, B lymphocytes express specificities characteristic of the B-cell population only, at their surface.

Ultrastructural demonstration of T cells in cutaneous tissue sections using specific anti-human T cell antiserum

The presence of T lymphocytes in the situ in cutaneous infiltrates of contact dermatitis and lichen planus has been demonstrated by an immunoelectronmicroscope technique. A specific anti-human T cell antiserum labelled with peroxidase-conjugated anti-immunoglobulin serum was used to reveal the specific human T lymphocyte antigen (HTLA) which was visualized ultrastructurally. This technique shows that labelling is limited to the surface membrane and allows study of the in situ interrelationship of T cells.

[Immunofluorescence and immunoperoxidase: a comparison for sensitivity in cutaneous immunopathology (author's transl)]

A comparative study of the sensitivities of the immunofluorescence (IF) and immunoperoxydase (IPo) techniques was undertaken. The material used was biopsies of various skin lesions and especially pemphigus, bullous pemphigoid, lupus erythematosus and dermatitis herpetiformis. Direct and indirect methods were performed for the detection of fixed immunoglobulins and complement deposits. With large deposits, immunoperoxydase and immunofluorescence show an equal sensibility and the labeling obtained with IPo is never more intensive than the labeling obtained with IF. In contrast, with small deposits, IPo was less sensitive than IF and appears negative in the majority of the cases and especially in dermatitis herpetiformis. These results are confirmed in using increasing dilutions of conjugates and can be explained by the difficulty in doing the observation of small positive deposits with IPo.

Defective leukocytotaxia and recurrent staphylococcal infecion: deficiency of leukocytotaxia and abnormal granulocytes associated with increase serum IgE levels in an adult with recurrent staphylococcal infection

A man who was suffering from recurrent staphylococcal infection had antecedent symptoms of severe pruritus. Laboratory investigations showed leukocytosis with eosinophilia, hyperimmunoglobulinemia of all fractions, but particularly of IgE, and a deficiency of cell-mediated immunity on in vivo testing. Phagocytosis and bactericidal activity of polymorphonuclear leukocytes were normal, but a cellular and serum-associated defect in leukocytotaxia was present. Ultrastructural changes were observed in polymorphonuclear leukocytes. Association of impaired leukocytotaxia and elevated levels of IgE is not uncommon. Recurrent bacterial infections in the patient described are probably related to defective chemotaxis.

Action of the "nude" gene on pigmentation of the coat in c57 black and c3 mice

The authors have studied pigmentary changes of skin and hair due to the presence of the "nude" gene in pigmented species (C 57 Bl. 6J, C3H). Morphological (histology, electron microscopy) and biochemical (polyacrylamide gel electrophoresis of tyrosinase activities) studies showed that the pigmentary alterations of the "nude" mice were related to hair cycle and hair growth wave pattern. In fact, in the "nude" mice the hair follicles evolves cyclically similarly to mice of normal coat. In depigmented skin, the hair follicles were in the resting phase and no soluble tyrosinase could be demonstrated.