Veiled Cells Research Articles

Rearrangement of S-100 immunoreactive Langerhans' cells in human psoriatic skin treated with peptide T

Dendritic cells marked by protein S-100 (S-100) antiserum in the suprabasal layers of the epidermis have previously been identified to be Langerhans' cells. In this study, S-100 immunoreactive cells have been investigated in psoriatic lesioned skin during and after peptide T treatment. Peptide T is an octapeptide with affinity for the CD4 receptor. Nine patients were intravenously infused with peptide T, 2 mg in 500 ml saline per day for 28 days. Sections from involved skin before, every week during, and after the treatment were processed by indirect immunofluorescence using S-100 antiserum. Before the treatment the epidermal Langerhans' cells were numerically decreased or even completely gone in the involved skin of psoriasis as compared to skin from normal healthy controls, while the dermal dendritic cells instead were increased and gathered in cell clusters around vascular structures. Four of the nine patients had histopathological improvements after the peptide T treatment, and, in those cases, the dendritic cells in the dermis were reduced in number, and the Langerhans' cells in the epidermis were numerically increased as well as even reversed to normal position and morphology. These changes in the distribution and density of Langerhans' cells represent their rearrangement during the course of psoriasis and/or the remission after peptide T treatment. It is assumed that in psoriasis, the loss of detectable Langerhans' cells are either due to activation (as part of the immune system) followed by migration from the epidermis to the afferent lymph vessels as so-called veiled cells, or inhibition of the expression of their marker molecules, and that the Langerhans' cells ‘return’ to their normal position and number after treatment.

Immunohistochemical detection of CD1A antigen in formalin-fixed and paraffin-embedded tissue sections with monoclonal antibody 010.

The immunoreactivity of a CD1a monoclonal antibody (MAb), denoted 010, was investigated by means of the streptavidin-biotin-peroxidase method in formalin-fixed and paraffin-embedded tissues from 47 cases. The samples comprised reactive lymphoid proliferations of skin, tonsil, and lymph node including dermatopathic lymphadenopathy and Langerhans' cell histiocytosis, Hodgkin's and non-Hodgkin's lymphomas, and thymomas. Interdigitating and dermal dendritic cells, veiled cells, Langerhans' cells, and also cortical thymocytes and their neoplastic counterparts displayed immunostaining with MAb 010 in paraffin sections. These results are identical to previous ones reported for other CD1a MAbs in fresh or frozen specimens. The findings suggest that the binding site of 010 is a fixation-resistant epitope of CD1a antigen which has not been previously identified.

A mouse aminopeptidase N is a marker for antigen‐presenting cells and appears to be co‐expressed with major histocompatibility complex class II molecules

To analyze the expression of mouse aminopeptidase N (APN) on the cells of the immune system a panel of rat monoclonal antibodies against mouse intestinal APN was generated. These antibodies were used to affinity purify functional mouse APN from both intestine and kidney, and by flow cytometry to examine the APN expression of the cells of the mouse immune system. An APN closely related, perhaps identical, to the intestinal APN was expressed on a subpopulation of spleen cells and stimulated peritoneal exudate cells, primarily representing antigen-presenting cells, such as B cells, macrophages, dendritic cells, and veiled cells. In contrast this APN expression could not be detected on thymocytes or spleen T cells. As a corollary, APN was expressed on monocyte, macrophage, and B lymphoma cell lines, but not on T hybridoma or thymoma cell lines. The expression of APN showed a striking correlation with the MHC class II expression in all the cell populations studied. This apparent co-expression suggests a role for APN in antigen processing.

Role of cathepsin D in the degradation of human serum albumin by peritoneal macrophages and veiled cells in antigen presentation

Murine peritoneal macrophages (PMØ) and veiled cells (VC) isolated from the thoracic duct of irradiated lymphadenectomized (MNLX) mice presented intact human serum albumin (HSA) to stimulated T lymphocytes, but VC were not as effective as PMØ in presenting the antigen. Pepstatin A significantly inhibited the presentation of HSA by VC. Lysates prepared from PMØ degraded [ 125I]HSA at pH 4.0 to peptides as demonstrated by SDS-polyacrylamide-gel electrophoresis and autoradiography. Degradation was inhibited by pepstatin A, suggesting that cathepsis D might be responsible for processing the antigen. In contrast, lysates prepared from VC did not degrade [ 125I]HSA. The localization of cathepsin D, by light microscopy, was examined on cytospins of PMØ and VC by means of a peroxidase antiperoxidase technique (PAP). Cathepsin D was found in vacuoles in the cytoplasm of PMØ and, in some cases, appeared to be bound to some areas of the cell surface, but the enzyme could not be detected in VC.

Tick salivary gland extract and interleukin-2 stimulation enhance susceptibility of lymphocytes to infection by Theileria parva sporozoites

Intracellular parasites show host cell specificity, and precise information on the range of host cells is a prerequisite for the identification of host molecules that account for the specificity and are involved in entry processes. The sporozoite stage of the tick-borne protozoan parasite Theileria parva binds to and enters bovine lymphocytes, but precise information on the susceptibility of other cell types present at the tick attachment site is unavailable. We quantitatively examined the susceptibility of cell types known to be present at the tick attachment site by a previously established in vitro assay. Apart from lymphocytes, sporozoites also bind to and enter macrophages and afferent lymph veiled cells; they do not bind to or enter fibroblasts, granulocytes, or erythrocytes. Sporozoites are not phagocytosed by the macrophages or veiled cells but enter them as they do lymphocytes. Since the tick attachment site is a region of cellular inflammation, we also examined the effects of agents known to be present in this area on lymphocyte susceptibility. Short-term preincubation of lymphocytes with tick salivary gland extract, with compounds that induce lymphocyte proliferation, or with interleukin-2 (IL-2), a cytokine produced by activated lymphocytes, increased host cell susceptibility by between 30 and 60%. The IL-2-induced increase in host cell susceptibility could be prevented by treating the lymphocytes with the monoclonal antibody IL-A 111, which reacts with the bovine IL-2 receptor alpha chain and inhibits IL-2-driven cell proliferation. The changes induced by tick salivary gland extract and IL-2 occurred in less than 90 min. Similarly, peripheral blood mononuclear cells from an animal previously immunized with a nonrelated antigen (trypanosome variant surface glycoprotein) and stimulated in vitro with the same antigen showed increases in host cell susceptibility of between 70 and 125%. In contrast, treatment of lymphocytes with gamma interferon did not induce any increase in host cell susceptibility.

ラット各種臓器組織における抗樹状細胞抗体が認識する抗原の分布

Dendritic cells (DC) are a group of cells which are constantly expressing MHC class II antigen, that is essential to antigen presentation for initiating immune responses. DC include many types of cells which are named separately for the reason of investigative processes and distribution, such as Langerhans cells, follicular dendritic cells, interdigitating cells, lymphoid dendritic cells, interstitial cells, veiled cells, indeterminated dendritic cells and so on. Because these cells are very similar to each other, these cells are classified as a family of cells. On the other hands, some diffrences were also found among these cells, and it is not clear whether the classification is suitable or not. Previously, we made a monoclonal antibody, KO 3, against rat DC in lymph nodes, and reported that KO 3-positive cells were distributed in several tissues. In this paper, we examined the distribution of the cells reacting with KO 3, 1F119, which was the other type of antibody to DC in rat, and anti-MHC class II in rats, also studied the relation between the distribution of KO 3-positive cells in tissues and the molecular weight of KO 3-positive band in western blotting. The results were as follows : 1. MHC class II-antigen appeared at the appropriate cells reacting with KO 3 in various tissues of rats. 2. The distribution of KO 3-positive cells in tissues was very similar to that of 1F119-positive cells, with the except of brain and bone marrow. 3. KO 3-positive band, in western blotting, appeared at 3 different parts equivalent for 28, 33, and 35 kDa in molecular weight in tissue extracts. 4. There were no DC subfamilies having specific KO 3-positive band alone.

Murine epidermal Langerhans cells as a model to study tissue dendritic cells.

Dendritic cells (DC) form a system of widely distributed antigen presenting cells that seems essential to initiate immmune responses 1. The study of epidermal Langerhans cells (LC) was important to unravel how the individual components of this system interact 2. It became evident that DC accomplish their task as “nature’s adjuvant” in the afferent limb of the immune system in three discrete steps: immature DC are located in peripheral non-lymphoid tissues (“tissue DC”) and are specialized to capture and process antigen (“sentinel function”). Following rapid downregulation of their antigen processing capacity they begin to develop into mature DC by acquiring the capacity to stimulate resting T cells. These cells then migrate as “veiled cells” via afferent lymph (or blood) to the T areas of the lymph node (or spleen) (“migratory function”), where they appear as “lymphoid DC”, select antigen-specific T cells from the circulating pool and stimulate them (“sensitizing function”). Here we will review the studies of murine LC that have helped to establish this concept of DC function. We will also outline recent data about the modulation of LC function by cytokines, the evidence that DC and LC constitute a distinct hematopoietic lineage, and hints for a novel role of LC as regulators of keratinocyte proliferation.

Follicular dendritic cells and dendritic cell nomenclature.

In the 10 years since the last nomenclature committee on dendritic cells met (Tew, Thorbecke and Steinman, J. Reticuloendothelial Society 31:371, 1982), considerable evidence has accumulated supporting the concept that Langerhans cells, interdigitating cells, and veiled cells are the same cell in different stages of maturation. It also appears that the follicular dendritic cell (FDC) is quite different from these dendritic cells. In short, it seems to me that we are dealing with two distinct dendritic cell types and that this concept should be clearly stated. I have a suggestion on how this might be done in Table 1. The designation “T cell associated dendritic cell” or “B cell associated dendritic cell” in Table 1 does not mean to imply that these interactions are absolute and exclusive. Rather, it is clear that one type of dendritic cells typically interacts with T cells and the other typically interacts with B cells.KeywordsDendritic CellGerminal CenterLymphoid FollicleDendritic MorphologyFollicular Dendritic Cell

In situ expression of B7/BB1 on antigen-presenting cells and activated B cells: an immunohistochemical study.

B7/BB1 is a physiological ligand for CD28, a receptor expressed on a major subset of T lymphocytes. B7/BB1 has been shown to be expressed on human blood dendritic cells and on in vitro activated (but not resting) B cells and monocytes. Ligation of CD28 with B7/BB1 up-regulates cytokine production and prevents the induction of anergy in T cells activated through TCR/CD3. We examined the in situ expression of B7/BB1 by immunohistochemistry with a novel mAb B7-24. Dendritic cells in skin (Langerhans cells), lymph node sinuses (veiled cells), and T cell zones of spleen and lymph nodes (interdigitating dendritic cells) were strongly positive for B7/BB1. B7/BB1 was also present on fetal thymus dendritic cells located at the cortico-medullar junction and the medulla, but absent in normal adult thymuses. Resident macrophages and endothelial cells did not stain, but in granulomatous inflammations B7/BB1 was found on macrophages and epitheloid cells. A subset of B immunoblasts and of germinal center B cells in lymph node and spleen was also found to express B7/BB1. Our findings on the distribution of B7/BB1 expression in tissues, in particular its expression on professional antigen-presenting cells, further substantiate the putative co-stimulatory role of B7/BB1 in T cell activation in vivo. The presence of B7/BB1 in fetal but not adult thymic medulla suggests a role for B7/BB1 in thymocyte maturation.

Skin dendritic cell-lymphocyte interactions in autologous system.

Skin tissue fluid and lymph contain migrating immune cells, among them large dendritic (veiled) cells (VC) and lymphocytes 1. These cells are continuously transported with lymph stream to the regional lymph nodes. This way the information about the presence of antigen can be transferred within minutes to the lymph node.2

Afferent lymph veiled cells prime CD4+ T cell responses in vivo.

The interdigitating cell (IDC) population of the lymph node paracortex is believed to be responsible for the induction of CD4+ T cell responses to soluble antigens. We have examined the role of afferent lymph veiled cells (ALVC), the putative precursors of IDC, in the induction of primary bovine CD4+ T cell responses in vivo. ALVC prepared from lymph draining an antigen inoculation site stimulated maximal responses in antigen-specific T cell clones as soon as 30 min after inoculation. In addition, antigen-pulsed ALVC were shown to induce primary antigen-specific T cell responses when administered in vivo. Observed influences of fixation and the addition of chloroquine or class II major histocompatibility complex-specific monoclonal antibodies on presenting function confirmed that ALVC process and present antigens using the endosomal pathway. We conclude that ALVC rapidly internalize antigens deposited in the periphery, and process them for presentation to naive T cells in the draining lymph node. Their function is, therefore, likely to be an important factor in the induction of primary T cell responses to soluble antigens in vivo.

The MRC OX-62 antigen: a useful marker in the purification of rat veiled cells with the biochemical properties of an integrin.

A mouse immunoglobulin G1 monoclonal antibody (mAb), MRC OX-62 (OX-62), was raised against density gradient-enriched rat veiled (dendritic) cells obtained from lymph. In suspensions of lymphoid cells, the OX-62 mAb only labeled cells with the characteristics of veiled cells. The OX-62 mAb was used with a magnetic cell sorter to enrich or deplete veiled cells, and the enriched veiled cells were potent stimulators in the primary allogeneic mixed leukocyte reaction. Immunohistochemical staining of tissue sections showed that the OX-62 mAb did not label all classical dendritic cells and was not restricted to this cell type. In lymphoid tissues, the labeling correlated with dendritic cells, but in skin, major histocompatibility complex class II+ cells were OX-62-, while another CD3+ cell with dendritic morphology was strongly OX-62+. It seems that the OX-62 mAb may be restricted to dendritic cells and probably to gamma/delta T cells. The OX-62 mAb will be of use in delineating minor subsets of cells with dendritic morphology in various tissues. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of veiled cell-enriched populations immunoprecipitated with the OX-62 mAb gave bands with the biochemical characteristics of an integrin. The OX-62 mAb recognized the alpha-like subunit.

Immune events in skin. I. Spontaneous cluster formation of dendritic (veiled) cells and lymphocytes from skin lymph.

To investigate the mechanism of spontaneous attachment of afferent lymph lymphocytes to dendritic cells, cells from canine skin lymph were used. There were 3.3 +/- 2.8% of veiled cells in clusters found in lymph flowing from the cannulated lymph vessel. The number of clusters forming ex vivo in the collected lymph samples increased as a function of time and was temperature dependent. Incubation of cells with proteolytic enzymes or monosaccharides did not alter cell interactions. The ability of veiled cells to bind lymphocytes was independent of divalent cations but reduced by xylocaine and retinoic acid. Among steroids only methylprednisolone showed an inhibitory effect on cluster formation. Indomethacin and acetylsalicylic acid had no blocking activity on cell binding. Also, no effect was seen after treatment with cyclosporine A and azathioprine. An enhanced cluster formation after desialation with neuraminidase was observed. The desialated cells were cultured in order to study their stimulatory and accessory cell functions. No enhancement of autologous mixed leucocyte reaction was seen, but a significantly higher responsiveness to a suboptimal dose of phytohaemagglutinin was observed. The N-ase-mediated non-specific cell attachment could be abrogated by cell washing or treatment with EDTA or xylocaine. This study indicates that cluster formation by skin lymph veiled cells and lymphocytes is a spontaneous process which cannot be controlled by means usually effective in regulating the in vitro induced clustering of antigen-stimulated cells.

Bovine afferent lymph veiled cells differ from blood monocytes in phenotype and accessory function.

Veiled cells have been prepared from bovine afferent lymph and their surface phenotype has been compared with that of blood monocytes using a panel of mAb that define bovine leukocyte Ag. It has been observed that the expression of CD1c and a putative bovine CD45R Ag is restricted within these populations to afferent lymph veiled cells (ALVC), whereas CD11b is expressed only on monocytes. The CD11a and CD11c specificities and an additional Ag defined by mAb 1LA24 (p110/75) are expressed by both cell types, although CD11a and p110/75 are found only on subpopulations of ALVC. In a comparison of accessory function, we have found that ALVC are considerably superior to blood monocytes both as stimulators in mixed leukocyte cultures and as presenters of soluble Ag to primed T cells. This superiority appears to be associated with an increased capacity to form clusters with responding lymphocytes. In addition, we have established that the capacity of ALVC to present soluble Ag to Ag-specific T cell clones resides almost exclusively in a subpopulation defined by the phenotype p110/75+ CD11a-.

リンパ節およびひ臓内Ｔ領域における樹状細胞の免疫組織化学的研究

Langerhans cells (LCs) in the epidermis and interdigitating reticulum cells (IDCs) in the lymph nodes are said to have the same morphological and immunological characteristics. In this paper, we examined LCs and IDCs in the superficial (cervical and inguinal), hilar and mesenteric lymph nodes, and also spleens, using anti S-100 protein and OKT-6 antibodies for immunostaining. Lymph nodes and spleens taken from 16 autopsies were used for the experiments. We were able to observe LCs which were positive for both anti S-100 protein and OKT-6 in the superficial and hilar lymph nodes. However, we could not find LCs in the mesenteric lymph nodes or spleens. The immunological and morphological features of LCs were similar to those of veiled cells in the marginal sinus possibly moving from the skin to the T-zone of the superficial and hilar lymph nodes. OKT-6 positive cells were not exactly identical with anti S-100 protein positive cells, because the total number of S-100 protein positive cells was greater than that of OKT-6 positive cells. The existence of a larger number of OKT-6 positive cells in the inguinal lymph nodes than in the cervical lymph nodes may be because there are more opportunities for the lower extremities to receive different kinds of stimuli than for the head. LCs may receive some stimulation from the external environment and/or retain antigens. LCs might also be responsible for T cell dependent immune responses. Our results suggest that LCs and IDCs have slightly different immunological characteristics, and therefore, they may have some different functions.

Dendritic Cells of the Skin

The dendritic shape of a given cell is by no means indicative of its origin and function. This is exemplified best by the ontogenetic and functional heterogeneity of dendritic cells in the skin. Even when focusing on bone marrow-derived dendritic cells, the mammalian skin contains at least three distinct lineages of dendritic cells, including Ia+ nonlymphoid dendritic cells (epidermal and dermal Langerhans cells, veiled cells in the lymphatics), dendritic epidermal T cells (mouse), and less well-characterized dermal dendrocytes. Methods exist that allow us to isolate and to purify these cells, to study their phenotype and function, and, thus, to clarify their role in both physiologic and pathologic conditions of the skin.

Sinus histiocytosis with massive lymphadenopathy: Immunological, cytogenetic and molecular studies

We describe a case of "sinus histiocytosis with massive lymphadenopathy" (SHML) studied by immunohistochemical, cytogenetic and molecular analysis. The immunophenotyping showed that the lymph node histiocytes were strongly positive for the S-100 protein and MoAb LeuM3, OKM5, KP1 and DRC-1; a portion of these cells was also positive for OKT6 and Leu3A, suggesting a possible relationship with the veiled cells, which represent an intermediate step in the pathway from the Langerhans cell to the interdigitating reticulum cell. Cytogenetic analysis showed a normal prevalent clone and a small hypodiploid clone and the molecular study showed no detectable involvement of the c-fms proto-oncogene, which is related to monocyte/macrophages. Unfortunately all these data do not seem sufficient to define the benign or neoplastic nature of the disease. Further investigations, immunophenotypical, cytogenetic and molecular, are needed to elucidate the pathogenesis of the disease, especially for more aggressive cases or for cases with unfavorable evolution.

The Surface of Dendritic Cells in the Mouse as Studied with Monoclonal Antibodies

A family of dendritic cells has been identified in situ and in vitro by microscopy and immunolabeling. The members of this family include the dendritic cells isolated from lymphoid organs, Langerhans cells [LC] of the epidermis, veiled cells in afferent lymph, and interdigitating cells [IDC] in the T-cell areas. Some common features to all members of the family are high levels of MHC class II antigens, a lack of most B and T cell markers, and an absence or low levels of macrophage/granulocyte antigens. This review summarizes the markers of mouse dendritic cells as assessed by a panel of monoclonal antibodies, and stresses a few recent findings. 1) In spleen, there are two populations of dendritic cells. More than 75% of isolated cells are 33D1+, NLDC145-, and J11d-, while the remainder have the reciprocal phenotype and thus share the NLDC145 antigen of IDC. Thymic dendritic cells, released by collagenase digestion, and epidermal LC also are 33D1-, NLDC145+, J11d+. 2) When epidermal LC are placed in culture, there are changes in cell function and phenotype. There is a decrease in Fc gamma receptors and the F4/80 macrophage antigen, an increase in class I and II MHC products and p55 IL-2 receptors, and persistence of the NLDC145 IDC antigen. The cultured LC thereby resembles the IDC. 3) A new antibody N418 shows that dendritic cells express the p150/90 member of the leukocyte beta 2 integrin family. Immunolabeling of tissue sections of spleen indicates that N418+ dendritic cells not only are present in the periarterial sheaths, the location of IDC, but also in "nests" at the periphery of the T area where 33D1 has been found. The peripheral collections interrupt the marginal zone of macrophages that separates white and red pulp, and places the dendritic cells in the path of T cells as they move through the white pulp. Therefore the members of the dendritic cell family have important markers in common, as well as differences that are associated with state of immunologic function and location.

Functional Characteristics of Veiled Cells from Canine Prenodal Lymph

The surgical interruption of afferent lymphatics in the hind limb of dog leads to peripheral lymph stasis. The stagnated lymph contains large numbers of immunocompetent cells originating solely from the skin. This experimental model allows a study of the functions of the afferent skin-draining lymph cell population, the recovery and assessment of the lymphokines and other mediators liberated by these cells during the culture, and the production of anti-sera against different types of lymph cells. In the present study, we focused on the functional, morphological and cytochemical evaluation of the non-lymphoid cells, isolated from the whole lymph cell population by means of the gradient centrifugation technique. The non-lymphoid cells were large, with an irregularly- shaped nucleus and numerous cytoplasmic projections, giving them a «eiled» cell (VC) appearance. All VC were strongly positive for DLA-class II antigens and membrane-associated ATP-ase, and 60% of them exhibited the activity of non-specific esterase. In the functional assays, VC displayed the potent accessory-cell activity in the mitogen-induced response of autologous blood- and lymph-derived lymphocytes. In the mixed leukocyte cultures, VC acted as stimulators of the allogeneic and autologous lymphocyte proliferation. The high spontaneous and mitogen-induced responsiveness of the whole lymph cell population was found to be dependent on the presence of VC. The small number of VC (5% of cultured cells) was sufficient to produce the above-mentioned effects. These results indicate that VC is a cell responsible for the antigen presentation in the skin-associated immune reactions in dog, which is relevant to the observations on similar cells from the other species.

A single step centrifugation method for the enrichment of veiled cells from canine afferent lymph

Veiled cells (VC) present in the afferent lymph of dogs with chronic lymphoedema could be enriched from 6% to about 50% VC by density gradient centrifugation on 15% metrizamide or discontinuous Percoll gradients. The recovery of VC was about 40% from 0.22 ± 0.07 × 10 6 VC/ml of lymph. The cells were strongly Ia positive and had cytoplasmic S 100 protein. They were also strongly ATP-ase positive and showed heterogeneity in acid phosphatase, peroxidase and non-specific esterase activity. Low density VC from canine afferent lymph were able to stimulate both blood and lymphatic lymphocytes in autologous mixed leukocyte reaction when present at concentration as low as 5% of cultured cells.