Kathrin Scheckenbach

T cells specific for HPV16 E7 epitopes in patients with squamous cell carcinoma of the oropharynx

Squamous cell carcinomas of the oropharynx (SCCO) are often infected with oncogenic human papilloma virus (HPV) subtype 16. To determine the frequency of T cells specific for human leukocyte antigen (HLA)‐A2.1 restricted HPV16 E7 protein‐derived epitopes, tetramer analysis was performed using peripheral blood lymphocytes of 20 HLA‐A2.1+ patients and 20 HLA‐A2.1+ healthy individuals. Tetramers specific for 3 HPV16 peptides (E711–20, E782–90 and E786–93), an influenza matrix peptide (a model recall antigen) or an HIV reverse transcriptase peptide (a model novel antigen) were used in multicolor flow analysis. The HPV‐specific T‐cell frequencies were correlated with the HPV16 E7 and p16 status in tumor sections. In vitro stimulation (IVS) with autologous dendritic cells (DC) pulsed with HPV16 E7 epitopes was performed to demonstrate proliferation and antitumor activity of the HPV‐responsive T cells. Frequencies of CD8+ T cells specific for HPV16 E7 peptides were not significantly different in patients with SCCO relative to normal donors. However, patients with tumors expressing HPV16 E7 (60%) and p16 (50%) had an increased frequency (p < 0.05) of T cells specific for the E711–20 epitope compared to those with tumors negative for both markers. HPV16 E711–20 and HPV16 E786–93 specific T cells were expandable upon IVS with cognate peptide‐pulsed DC and were reactive against peptide‐pulsed targets or, in case of the E711–20 epitope‐specific T cells, against HPV16 E7 expressing CaSki cell line. Thus, in patients with HPV16+ SCCO, precursor T cells specific for E711–20 epitope are present (1/3,947) in the circulation, are responsive to stimulation with the cognate viral peptide and recognize in vitro HPV16 E7+ tumor cells. Further studies have to elucidate why those T cells are unable to eliminate the tumor in vivo and this might also allow for finding potential strategies that will increase the chances of developing a future HPV‐based vaccine in patients with SCCO.

Alterations in the p53 pathway and their association with radio- and chemosensitivity in head and neck squamous cell carcinoma

Chemotherapy and/or radiotherapy are established measures in treatment protocols of head and neck squamous cell carcinoma (HNSCC). However, we still lack reliable predictive markers for the response to radio- and chemotherapy. The p53 pathway is involved in stress response and thus might influence chemo-/radiosensitivity. Using 29 HNSCC cell lines previously characterized for p53 mutations, we simultaneously analyzed several key players in the p53 pathway by RT-PCR, transcript sequencing and immunohistochemistry, and investigated their association with chemosensitivity and radiosensitivity. Cell lines with p53 mutations were slightly more sensitive to cisplatin than those with wild-type p53. The type of mutation did not influence radio- or chemosensitivity. p14(ARF), an activator of p53, was lost or mutated in all cell lines. Three cell lines showed overexpression of HDM-2, a major negative regulator of p53; however, HDM-2 levels did not correlate with radio- or chemosensitivity. HPV-16 oncoproteins were detected in one highly chemoresistant cell line. Our findings suggest that molecular events resulting in the inactivation of the p53 pathway occur in all HNSCC cell lines. However, single alterations in the p53 pathway are not reliable predictors for the response to radio- or chemotherapy in HNSCC.

A novel mechanism for anti-EGFR antibody action involves chemokine-mediated leukocyte infiltration

Overexpression of the epidermal growth factor receptor (EGFR) is a hallmark of squamous cell carcinoma of the head and neck (SCCHN). Monoclonal antibodies (mAbs) against EGFR are currently used for therapy of recurrent or metastatic disease; however, their mode of action is not completely understood. To investigate the immunological effects of anti‐EGFR mAb, we generated a three‐dimensional spheroid model of EGFR‐expressing SCCHN and used this model to study the effect of anti‐EGFR mAb on leukocyte migration toward tumors. Pretreatment with the blocking anti‐EGFR mAb EMD 72000, its F(ab′)2 fragments or an EGFR tyrosine kinase inhibitor led to substantially increased leukocyte infiltration into EGFR overexpressing tumor spheroids, but not into those with low EGFR expression. Nonblocking anti‐EGFR mAb or fibroblast‐specific mAb did not affect leukocyte infiltration, suggesting that the observed increase in leukocyte infiltration depends on interference with EGFR activation. Using a human cytokine macroarray, we demonstrated that the blockade of EGFR by anti‐EGFR mAb in EGFR‐overexpressing SCCHN cells leads to differential expression of several cytokines and chemokines, including the chemokine MCP‐1/CCL‐2. The significant upregulation of MCP‐1/CCL2 on exposure to anti‐EGFR mAb was confirmed by quantitative PCR and enzyme‐linked immunospot analyses. Moreover, blocking anti‐MCP‐1 antibody inhibited leukocyte migration toward tumor cells induced by anti‐EGFR mAb, pointing to an important role of MCP‐1/CCL2 in anti‐EGFR mAb‐induced leukocyte migration. Our findings demonstrate that anti‐EGFR mAb induces leukocyte infiltration to tumor spheroids by upregulating chemokine expression. This novel mechanism for anti‐EGFR mAb action may contribute to the antitumor effects of anti‐EGFR mAb in vivo.

Reliable detection of p53 aberrations in squamous cell carcinomas of the head and neck requires transcript analysis of the entire coding region.

Aberrations of the p53 tumor suppressor gene are common events in squamous cell carcinomas of the head and neck (SCCHN). However, reported frequencies range considerably, and the predictive value of aberrant p53 is continuing to be an issue of controversy. These inconsistencies are possibly caused by methodical limitations.

Comprehensive analysis of the p53 status in mucosal and cutaneous melanomas

The abrogation of the function of the “gatekeeper of the genome”, p53, is the most prevalent molecular alteration in solid human tumors. Regarding melanomas the involvement of p53 alterations is discussed controversially to date. In order to evaluate the status of p53 in detail, primary tumors and metastases of 63 sporadic cutaneous (CM) and mucosal (MuM) melanomas were examined by immunohistochemistry and sequence analysis of the entire coding region of the p53 transcript, i.e., exons 2 to 11. In addition, loss of heterozygosity (LOH) and loss of allele‐specific transcription (LOT) were determined. Accumulation of the p53 protein occurred in most of the CM and MuM specimens (71% and 58%, respectively). In contrast, protein stabilizing p53 mutations were observed in 14% of the CM and no mutation was found in MuM specimens. Two of the aberrations located outside the core domain. LOH was detected in 22% CM and 58% MuM, and LOT in 25% of the CM specimens. The genotype distribution at the polymorphic p53 codon 72 in melanoma patients differed significantly from control subjects. The calculation of odds ratios (OR) and 95% confidence intervals (CI) indicated an increased risk for developing cutaneous melanomas in individuals carrying the Pro‐coding allele. Altogether, aberrant p53 expression appears to be a common event in both CM and MuM.

Comparison of the nasal release of IL-4, IL-10, IL-17, CCL13/MCP-4, and CCL26/eotaxin-3 in allergic rhinitis during season and after allergen challenge.

Background Allergic rhinitis is an inflammatory disease characterized by local overproduction of type 2 cytokines and tissue eosinophilia. Recent research suggests the involvement of additional cytokines such as IL-17, chemokine (C-C motif) ligand (CCL) 26/eotaxin-3, and CCL13/monocyte chemoattractant protein-4 (MCP-4) in its pathophysiology. Furthermore, bronchial epithelial cells treated with IL-17 and type 2 cytokines distinctively up-regulated eotaxin-3 gene expression. In this study we investigated the kinetics of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in seasonal allergic rhinitis volunteers after nasal allergen challenge (NAC) and their release during natural pollen exposure. Methods The nasal lavages of 15 symptomatic allergic and 14 nonallergic subjects were collected during the pollination season. Additionally, six allergic subjects underwent a single unilateral nasal allergen and control challenge out of season, and nasal secretions were collected. Levels of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in nasal lavages and secretions were measured using an electrochemiluminescent assay. Results After NAC, allergic subjects had a significant immediate response of nasal symptoms as well as a significant increase at 5 hours of IL-4, IL-10, and IL-17 and at 2, 5, and 24 hours significantly raising levels of eotaxin-3. IL-17 and eotaxin-3 concentrations at 5 hours were correlated (r = 0.94; p = 0.005). During natural pollen exposure, barely detectable levels of IL-17 in allergic subjects were also correlated with eotaxin-3 (r = 0.62; p = 0.01). Eotaxin-3 and MCP-4 levels were significantly elevated 9- or 3.7-fold, respectively, and IL-10 and, unexpectedly, IL-4 were significantly lower in allergic subjects compared with nonallergic subjects. Conclusion Nasal IL-17, MCP-4, and, possibly, eotaxin-3 may aggravate and IL-10 may alleviate nasal mucosal allergy.

Emerging therapeutic options in fulminant invasive rhinocerebral mucormycosis

OBJECTIVE Five cases of rhinocerebral mucormycosis (RCM) with different courses of illness and outcomes also due to different therapeutical strategies including Posaconazole as a new therapeutic option are described. Predisposing conditions for RCM are diabetes mellitus and immunosuppression. Diagnosis is often delayed because patients complain about nonspecific symptoms of acute rhinosinusitis, and initial CT imaging is unimpressive. Progressive disease, however, leads to early orbital and cerebral invasion. Due to the lack of typical clinical signs, diagnosis relies on histopathology. Therapy consists of the management of predisposing factors, radical surgical intervention and systemic antifungal therapy. METHODS We describe five cases of RCM with different comorbidities and outcomes. RESULTS RCM remains a diagnostic and therapeutic challenge because it begins with nonspecific symptoms and ends as fulminant disease with high mortality. Here, systemic treatment with Posaconazole appears to be a more effective alternative to amphotericin. CONCLUSION If a patient is suspected having RCM, improvement of predisposing diseases, radical surgical debridement and effective systemic antifungal therapy must be instituted immediately.

Treatment of the bone marrow failure in Fanconi anemia patients with danazol

More than 90% of Fanconi anemia (FA) patients experience progressive bone marrow failure during life with a median onset at 8 years of age. As matched sibling donor transplantation as preferred treatment is not available for the majority of patients, several synthetic androgens have been used as short-term treatment options for the marrow failure in FA patients for more than 50 years. Here, we retrospectively collected data on eight FA patients who received danazol for the off-label treatment of their marrow failure at a starting dose of approximately 5mg/kg body weight/die. The hematological parameters at the initiation of treatment were hemoglobin (Hb) <8 g/dL and/or thrombocytes <30,000/μl. In 7 out of 8 FA patients, the values for both parameters rose on average >50% over the starting counts within 6 months and remained stable for up to 3 years despite careful reduction of the danazol dose per kg body weight. In 4 patients with a follow-up of 3 years, the platelets finally reached an average of 68,000/μL or 2.8 times over the starting values, while the Hb remained stable >11 g/dL. Danazol was reduced to 54% of the starting dose or 2.6 mg/kg/die. One FA-A patient with an unusually severe phenotype did not response with her PB counts to either danazol or oxymethalone within 6 months. None of the patients developed severe or unacceptable side-effects from the danazol treatment that led to the discontinuation of therapy. This initial description suggests that danazol might be an effective and well-tolerated treatment option for delaying the progressive marrow failure in FA patients for at least 3 years and longer.

The release of IL-31 and IL-13 after nasal allergen challenge and their relation to nasal symptoms

BackgroundIL-31, a recently discovered member of the gp130/IL-6 cytokine family, is mainly expressed by human mast cells and T helper type 2 cells. IL-31 is a key trigger of atopic dermatitis. Recent studies also suggest a role of IL-31 in the pathogenesis of other allergic diseases including allergic rhinitis. In the present study we studied the release of IL-31 and IL-13 in allergen-challenged allergic rhinitis patients.MethodsSeven seasonal allergic volunteers underwent unilateral nasal provocation with allergen (and a control challenge) with the disc method out of the allergy season. Nasal symptom scores (rhinorrhea, itching, sneezing, obstruction) and bilateral nasal secretions were quantified before and after allergen provocation. IL-13 and IL-31 in nasal secretions and serum were measured by electrochemiluminescent immunoassay or ELISA, respectively.ResultsNasal allergen challenge induced the typical clinical symptoms and physiological changes. IL-31 and IL-13 in nasal secretions increased in four and five, respectively, volunteers at 5 h after allergen but not after control challenge. We observed correlation trends between nasal IL-31 concentrations and IL-13 concentrations (r = 0.9, p = 0.002), and IL-31 contents and symptom scores (r = 0.9, p = 0.013) 5 h after allergen provocation. No IL-31 could be detected contralaterally or systemically in the sera.ConclusionsThe observed local upregulation of IL-31 mainly during the late phase reaction after nasal allergen challenge suggests a role of IL-31 in allergic rhinitis. In which way IL-31 modulates the inflammatory reaction and type 2 responses in allergic rhinitis remains to be investigated.

Nasal levels of soluble IL‐33R ST2 and IL‐16 in allergic rhinitis: inverse correlation trends with disease severity

Serum levels of IL‐16, IL‐33 and the decoy receptor of IL‐33, soluble ST2, are elevated in allergic rhinitis. Recent studies show that IL‐16, soluble ST2 or anti‐IL‐33 reduce type 2 cytokines (such as IL‐5) and eosinophilia in murine models of allergic asthma or allergic rhinitis respectively.