Phenotypic and Functional Heterogeneity Among Murine Epidermal-Derived Dendritic Cell Clones

We have established recently long-term dendritic cell lines from the epidermis of new born BALB/c mice. These lines, termed XS series, resembled epidermal resident Langerhans cells or their progenitors in terms of surface phenotype, antigen-presenting capacity, and growth factor requirement. We examined in this study the degree of clonal heterogeneity among XS cells with respect to each of these features. Twelve stable clones were established by limiting dilution microculture from 8-10-week-old cultures of the XS52 or XS20 line. Despite the uniform expression of CD45, these clones varied substantially in their expression of Ia, B7-1, and B7-2 molecules. They also varied significantly in their relative efficiency in activating T cells, Finally, remarkable clone-to-clone heterogeneity was also observed in their growth factor responsiveness; some clones responded equally well to granulocyte macrophage-colony-stimulating factor and to colony-stimulating factor-1, whereas others responded preferentially to one or the other of these factors. We propose that the observed clonal heterogeneity in XS cells reflects possible heterogeneity in the state of maturation and mitotic potential among the starting populations, i.e., skin-associated dendritic cells in newborn mice

Reciprocal Cytokine-Mediated Cellular Interactions in Mouse Epidermis: Promotion of γ δ T-Cell Growth by IL-7 and TNFα and Inhibition of Keratinocyte Growth by γIFN

A unique subset of γδ T cells, termed dendritic epidermal T cells (DETC), resides in symbiosis with keratinocytes in mouse epidermis. We have shown previously that interleukin 7 (IL-7) which is produced by keratinocytes, promotes growth and prevents apoptosis in DETC. To extend this observation, we examined 12 cytokines, each of which is expressed by epidermal cells at mRNA and/or protein levels, for their capacities to modulate the growth of DETC. Cytokines examined included IL-1α, IL-2, IL-3, IL-4, IL-6, IL-7, IL-8, IL-10, tumor necrosis factor-α (TNFα), interferon-γ (IFNγ) granulocyte/macrophage-colony stimulating factor (GM-CSF) and macrophage inflammatory protein-1γ (MIP-1γ). When tested individually, IL-2 and IL-7 promoted maximal growth of the long-term cultured DETC line 7-17. When tested in combinations, synergistic growth- promoting effects were seen with IL-2 and IL-4 or IL-7, and with IL-7 and IL-4 or TNFγ. Dose-response experiments demonstrated that TNFγ, which is produced by keratinocytes, enhances IL,-7-induced DETC proliferation, but inhibits IL-2 – induced proliferation. The mouse keratinocyte-derived cell line Pam 212 was used to test these cytokines for their capacities to regulate keratinocyte growth. Only γIFN, which is produced by DETC, inhibited proliferation in a dose-dependent fashion. These results illustrate three reciprocal pathways by which epidermal cytokines regulate the growth of epidermal cells: 1) a paracrine mechanism by which keratinocyte-derived cytokines (e.g., IL-7 and TNFα) promote the growth of DETC, 2) an autocrine mechanism by which DETC-derived cytokines (e.g., IL-2 and IL-4) support their own growth, and 3) a reciprocal pathway in which a cytokine produced by resident epidermal leukocytes (e.g., γIFN) modulates the growth of keratinocytes

Dendritic Epidermal T Cells: Lessons from Mice for Humans

Dendritic epidermal T cells (DETC) in mice form part of a primitive system of epithelial-resident T cells characterized by the expression of gd T-cell receptors (TCR). Critical attributes that characterize DETC include their highly restricted T-cell receptor gene utilization, proliferation and maturation within epidermis, a capacity to kill relevant skin-derived tumor targets, and the ability to modulate immune responses that are initiated and expressed in skin. Contemporary knowledge suggests that DETC and the related skin-directed gd T cells found in humans play important roles in maintaining the immunologic integrity of skin

Mouse Dendritic Epidermal T Cells Exhibit Chemotactic Migration Toward PAM 212 Keratinocyte Culture Supernatants

Dendritic epidermal T cells (DETCs) are Thy-1+ CD45+, CD3+, CD4-, CD8-, and T-cell receptor-Vγ3/Vδ1++ leukocytes that reside normally in adult mouse skin. We have demonstrated previously that keratinocytes serve as adhesion substrates for DETCs, and that interleukin 7 (IL-7), which is produced by keratinocytes, serves as a growth factor for DETCs. The present study was conducted to address the mechanisms by which DETCs migrate into the epidermis, reasoning that keratinocytes may also be a source of chemotactic activity. Short-term DETC lines were 35S-labeled and tested for migration toward Pam 212 keratinocyte culture supernatants using a modified Boyden chamber method; cell movement from upper chambers toward test samples in lower chambers was traced by counting radioactivity. DETC displayed rapid (within 60 min) and marked (>50%) migration toward keratinocyte supernatants. The majority of cells that had migrated into keratinocyte supernatants expressed the Vγ3 T-cell receptor, thus verifying that the migrating cells were DETCs. Addition of keratinocyte supernatants to the upper chambers completely blocked migration, suggesting its chemotactic nature. By contrast, no DETC migration was observed toward 3T3 fibroblast supernatants. Chemotactic activities were 1) produced by Pam 212 cells even in the absence of serum; 2) greater than 12 kD in size; 3) heat and pH labile; 4) trypsin sensitive; and 5) precipitated by 60- 100% ammonium sulfate. Several cytokines (e.g., IL-1α and IL-8) failed to mediate DETC migration when added to the lower chambers. Likewise, the same cytokines, when added to the upper chambers, failed to inhibit DETC migration toward Pam 212 supernatants. These results support our hypothesis that keratinocytes facilitate the residence of DETC in epidermis by secreting unique chemotactic factors, by providing adhesion substrates, and by elaborating specific growth factors

Unusual abscesses associated with colon cancer: report of three cases

Three cases of colon cancer accompanied by unusual abscess formation are reported. Case I : A 77-year-old man was diagnosed with a paracolic abscess formation behind the cecum and a swollen appendix by computed tomography (CT) scan. Case II : An 85-year-old woman was diagnosed with an abscess formation of the right iliopsoas muscle, a swollen appendix, and a thickened right colon wall by CT scan. After antibiotic therapy failed, both patients underwent ileocecal resection urgently under suspicion of appendicitis, but cecal cancer around the entrance to the appendix caused secondary appendicitis in both cases. Case III : A 50-year-old woman was diagnosed with sigmoid colon cancer with an abscess formation in the pelvic cavity concomitant with ovarian tumor. A Hartmann procedure was performed, and a pathological examination revealed that a subserosal abscess behind the sigmoid colon cancer perforated the rectum with abscess formation. All cases were definitively diagnosed intraoperatively. The cancer recurred in cases I and III. We emphasize that precise surgical evaluation has an important role in the diagnosis of these complicated diseases. In addition, surgery affords the patient the best chance of recovery, and in these advanced cases radical treatment is recommended as early as possible

Phase shift spectra of a fiber-microsphere system at the single photon level

We succeeded in measuring phase shift spectra of a microsphere cavity coupled with a tapered fiber using a weak coherent probe light at the single photon level. We utilized a tapered fiber with almost no depolarization and constructed a very stable phase shift measurement scheme based on polarization analysis using photon counting. Using a very weak probe light (\bar{n} = 0:41), we succeeded in observing the transition in the phase shift spectrum between undercoupling and overcoupling (at gap distances of 500 and 100 nm, respectively).We also used quantum state tomography to obtain a 'purity spectrum'. Even in the overcoupling regime, the average purity was 0.982 \pm 0.024 (minimum purity: 0.892), suggesting that the coherence of the fiber-microsphere system was well preserved. Based on these results, we believe this system is applicable to quantum phase gates using single light emitters such as diamond nitrogen vacancy centers.Comment: 8 pages, 3 figure