Barbara Del Frari

Epidermal Langerhans Cells Rapidly Capture and Present Antigens from C-Type Lectin-Targeting Antibodies Deposited in the Dermis

Antigen-presenting cells can capture antigens that are deposited in the skin, including vaccines given subcutaneously. These include different dendritic cells (DCs) such as epidermal Langerhans cells (LCs), dermal DCs, and dermal langerin+ DCs. To evaluate access of dermal antigens to skin DCs, we used mAb to two C-type lectin endocytic receptors, DEC-205/CD205 and langerin/CD207. When applied to murine and human skin explant cultures, these mAbs were efficiently taken up by epidermal LCs. In addition, anti-DEC-205 targeted langerin+ CD103+ and langerin- CD103- mouse dermal DCs. Unexpectedly, intradermal injection of either mAb, but not isotype control, resulted in strong and rapid labeling of LCs in situ, implying that large molecules can diffuse through the basement membrane into the epidermis. Epidermal LCs targeted in vivo by ovalbumin-coupled anti-DEC-205 potently presented antigen to CD4+ and CD8+ T cells in vitro. However, to our surprise, LCs targeted through langerin were unable to trigger T-cell proliferation. Thus, epidermal LCs have a major function in uptake of lectin-binding antibodies under standard vaccination conditions.

The Internal Mammary Artery Perforator (IMAP) Breast-Flap Harvested From an Asymmetric Hyperplastic Breast for Correction of a Mild Funnel Chest Deformity

Pectus excavatum deformity is the most frequent congenital anomaly of the thoracic wall. If the invasive surgical procedures of thoracoplasty are not indicated or the patient refuses them, alternative treatment options should be considered. In such cases, local or distant transposition of autologous tissue could be appropriate. This report presents a selected case of funnel chest deformity and concomitant unilateral breast hyperplasia. Both deformities were corrected simultaneously using a pedicled internal mammary artery perforator (IMAP) flap dissected from the hyperplastic breast. This is a safe, reliable, low-morbidity, one-stage option for adult women that uses an easy-to-harvest flap for simultaneous correction of mild funnel chest deformity and concomitant breast hyperplasia with a single resulting scar.

Reconstruction of large head and neck deformities: experience with free gracilis muscle and myocutaneous flaps.

Microvascular free flaps continue to revolutionize coverage options in head and neck reconstruction. The authors describe their experience with the gracilis free flap and the myocutaneous gracilis free flap with reconstruction of head and neck defects. Eleven patients underwent 12 free tissue transfer to the head and neck region. The reconstruction was performed with the transverse myocutaneous gracilis (TMG) flap (n = 7) and the gracilis muscle flap with skin graft (n = 5). The average patient age was 63.4 years (range, 17–82 years). The indications for this procedure were tumor and haemangioma resections. The average patient follow‐up was 20.7 months (range, 1 month–5.7 years). Total flap survival was 100%. There were no partial flap losses. Primary wound healing occurred in all cases. Recipient site morbidities included one hematoma. In our experience for reconstruction of moderate volume and surface area defects, muscle flaps with skin graft provide a better color match and skin texture relative to myocutaneous or fasciocutaneous flaps. The gracilis muscle free flap is not widely used for head and neck reconstruction but has the potential to give good results. As a filling substance for large cavities, the transverse myocutaneus gracilis flap has many advantages including reliable vascular anatomy, relatively great plasticity and a concealed donor area.

Refinements in pectus carinatum correction: the pectoralis muscle split technique

BACKGROUND The standard approach for correction of pectus carinatum deformity includes elevation of the pectoralis major and rectus abdominis muscle from the sternum and adjacent ribs. A postoperative restriction of shoulder activity for several weeks is necessary to allow stable healing of the elevated muscles. To reduce postoperative immobilization, we present a modified approach to the parasternal ribs using a pectoralis muscle split technique. METHODS At each level of rib cartilage resection, the pectoralis muscle is split along the direction of its fibers instead of elevating the entire muscle as performed with the standard technique. From July 2000 to May 2007, we successfully used this technique in 33 patients with pectus carinatum deformity. RESULTS After the muscle split approach, patients returned to full unrestricted shoulder activity as early as 3 weeks postoperatively, compared to 6 weeks in patients treated with muscle flap elevation. Postoperative pain was reduced and the patients were discharged earlier from the hospital than following the conventional approach. CONCLUSIONS The muscle split technique is a modified surgical approach to the parasternal ribs in patients with pectus carinatum deformity. It helps to maintain pectoralis muscle vascularization and function and can reduce postoperative pain, hospitalization, and rehabilitation period.

Human skin dendritic cells can be targeted in situ by intradermal injection of antibodies against lectin receptors

Skin dendritic cells (DC) express C‐type lectin receptors for the recognition of pathogens. Langerhans cells (LC) express the receptor Langerin/CD207, whereas DEC‐205/CD205 is mainly expressed by dermal DC, but can also be detected at low levels on LC. In this study, we tested an ex vivo approach for targeting DC in situ with monoclonal antibodies (mAb) against Langerin and DEC‐205. The targeting mAb was injected intradermally into human skin biopsies or added to the medium during skin explant culture. Corresponding to the expression patterns of these lectin receptors on skin DC, Langerin mAb was detected merely in LC in the epidermis and DEC‐205 mainly in dermal DC in human skin explants, regardless of the application route. Migratory skin DC bound and carried targeting mAb from skin explants according to their lectin receptor expression profiles. In contrast to the very selective transport of Langerin mAb by LC, DEC‐205 mAb was more widely distributed on all CD1a+ skin DC subsets but almost absent in CD14+ dermal DC. As effective vaccination requires the addition of adjuvant, we co‐administered the toll‐like receptor (TLR)‐3 ligand poly I:C with the mAb. This adjuvant enhanced binding of DEC‐205 mAb to all skin DC subsets, whereas Langerin targeting efficacy remained unchanged. Our findings demonstrate that LC can be preferentially targeted by Langerin mAb. In contrast, DEC‐205 mAb can be bound by all CD1a+ skin DC subsets. The efficacy of DEC‐205 mAb targeting strategy can be boosted by addition of poly I:C underlining the potential of this combination for immunotherapeutical interventions.

Inframammary fold reconstruction with a deepithelialized skin flap.

Sagging of the remaining breast behind the inframammary fold after breast reduction or breast augmentation may necessitate revisional surgery. The authors achieved inframammary fold reconstruction by reconstruction of the inframammary crease ligament through a deepithelialized skin flap that is anchored to the periosteum of the fifth or sixth rib. They present their simple and safe technique.

Diced autologous rib cartilage for primary treatment or refinement of minor chest wall deformities.

Background: Various methods of corrective thoracoplasty for congenital anterior chest wall deformities have been described. To date, no studies have described the use of diced cartilage as a surgical procedure in thoracoplasty. The authors present their experience with 23 patients for whom diced cartilage grafts were used as an innovative approach for thoracoplasty. Methods: A retrospective review of 23 patients was performed. From January of 2004 to September of 2010, 18 patients underwent repair of pectus excavatum, three patients underwent repair of pectus arcuatum, and two patients underwent repair of pectus carinatum using diced rib cartilage grafts. Intraoperative and postoperative complications, patient satisfaction, and clinical outcome were evaluated. Preoperative and postoperative photographs were examined, and the results were assessed by independent surgeons. Results: The mean patient follow-up was 18.1 months. No major complications were observed in the perioperative period. Postoperative complications were mild recurrence of deformity (n = 2). No graft extrusion, infection, or contour irregularities occurred. The patients rated their cosmetic results as very good. All 25 of the wrapped diced cartilage grafts appear to have survived completely, with only one partial graft absorption. One patient had palpable diced cartilage. Conclusions: The diced cartilage graft technique is a novel and safe procedure in thoracoplastic refinement procedures with clear advantages, including limited surgical trauma, autogenous material, easy preparation, absence of significant donor-site morbidity, absence of additional costs, high patient satisfaction, and good aesthetic results. The authors advocate using this technique for augmentation and contouring of minor anterior wall deformities in selected patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV. Figure. No caption available.

CD34+ -derived Langerhans cell-like cells are different from epidermal Langerhans cells in their response to thymic stromal lymphopoietin.

Thymic stromal lymphopoietin (TSLP) endows human blood‐derived CD11c+ dendritic cells (DCs) and Langerhans cells (LCs) obtained from human epidermis with the capacity to induce pro‐allergic T cells. In this study, we investigated the effect of TSLP on umbilical cord blood CD34+‐derived LC‐like cells. These cells are often used as model cells for LCs obtained from epidermis. Under the influence of TSLP, both cell types differed in several ways. As defined by CD83, CD80 and CD86, TSLP did not increase maturation of LC‐like cells when compared with freshly isolated LCs and epidermal émigrés. Differences were also found in the production of chemokine (C‐C motif) ligand (CCL)17. LCs made this chemokine only when primed by TSLP and further stimulated by CD40 ligation. In contrast, LC‐like cells released CCL17 in response to CD40 ligation, irrespective of a prior treatment with TSLP. Moreover, the CCL17 levels secreted by LC‐like cells were at least five times higher than those from migratory LCs. After maturation with a cytokine cocktail consisting of tumour necrosis factor‐α, interleukin (IL)‐1β, IL‐6 and prostaglandin (PG)E2 LC‐like cells released IL‐12p70 in response to CD40 ligation. Most importantly and in contrast to LC, TSLP‐treated LC‐like cells did not induce a pro‐allergic cytokine pattern in helper T cells. Due to their different cytokine secretion and the different cytokine production they induce in naïve T cells, we conclude that one has to be cautious to take LC‐like cells as a paradigm for ‘real’ LCs from the epidermis.

Epidermal overexpression of xenobiotic receptor PXR impairs the epidermal barrier and triggers Th2 immune response

The skin is in daily contact with environmental pollutants, but the long-term effects of such exposure remain underinvestigated. Many of these toxins bind and activate the pregnane X receptor (PXR), a ligand-activated transcription factor that regulates genes central to xenobiotic metabolism. The objective of this work was to investigate the effect of constitutive activation of PXR in the basal layer of the skin to mimic repeated skin exposure to noxious molecules. We designed a transgenic mouse model that overexpresses the human PXR gene linked to the herpes simplex VP16 domain under the control of the keratin 14 promoter. We show that transgenic mice display increased transepidermal water loss and elevated skin pH, abnormal stratum corneum lipids, focal epidermal hyperplasia, activated keratinocytes expressing more thymic stromal lymphopoietin, a T helper type 2/T helper type 17 skin immune response, and increased serum IgE. Furthermore, the cutaneous barrier dysfunction precedes development of the T helper type 2/T helper type 17 inflammation in transgenic mice, thereby mirroring the time course of atopic dermatitis development in humans. Moreover, further experiments suggest increased PXR signaling in the skin of patients with atopic dermatitis when compared with healthy skin. Thus, PXR activation by environmental pollutants may compromise epidermal barrier function and favor an immune response resembling atopic dermatitis.

Complications Related to Pectus Carinatum Correction: Lessons Learned from 15 Years' Experience. Management and Literature Review.

Background: Various methods of corrective thoracoplasty for pectus carinatum deformity have been described, but to date no studies describe a review of complications and how to manage them. Complications are dependent not only on the technique used and the patient’s age, but also on the experience of the treating surgeon. The authors present their 15 years’ experience with surgical correction of pectus carinatum and the complications that have occurred. A literature review regarding complications with pectus carinatum surgery is performed. Methods: A retrospective review of 95 patients (mean age, 19 years) was performed. One hundred four surgical procedures for repair of pectus carinatum were performed from July of 2000 to July of 2015 using a modified Ravitch technique, bioabsorbable material, postoperative bracing, and in some cases a diced rib cartilage graft technique. Intraoperative and postoperative complications were evaluated. Results: The mean patient follow-up was 13.6 months (range, 4 months to 9.75 years). Intraoperative complications were pleura lesion and laceration of the internal mammary vein. Postoperative complications were recurrent mild protrusion, persistent protrusion of one or two costal cartilages, minor wound healing delay, skin ulcer, hypertrophic scar, transient intercostal dysesthesia, marginal pneumothorax, seroma, meningitis, and epidural hematoma. Conclusions: In our reported series of pectus carinatum repair, increasing experience and progressively less extensive techniques have resulted in fewer complications, low morbidity, and early return to activity. Complications were observed in the early period of application, predominantly because of a lack of experience, and usually subsided with increasing numbers of patients and frequency of surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.