Suboptimal recognition of a T cell epitope of the major dog allergen Can f 1 by human T cells

We have previously proposed that mammalian lipocalin allergens are recognized suboptimally by the human immune system due to their homology with endogenous lipocalins. Here, we have characterized in detail the human T cell recognition of one of the previously identified T cell epitopes of the major dog allergen Can f 1, contained in peptide p105–120. A panel of peptide analogues (altered peptide ligands, APLs) of p105–120 was tested on two specific T cell clones restricted by different human leukocyte antigen (HLA) alleles. Interestingly, we identified for both of the clones several heteroclitic APLs that were capable of stimulating them at 10–30-fold lower concentrations than the natural peptide. Moreover, one of the heteroclitic APLs identified with the T cell clones, L115F, was observed to induce a stronger polyclonal T cell response than the natural allergen peptide from the peripheral blood mononuclear cells (PBMCs) of six Can f 1-allergic subjects studied. The heteroclitic APLs bound with the same affinity as p105–120 to common HLA-DR- and HLA-DP-alleles, suggesting that their improved stimulatory capacity is attributable to a more efficient T cell receptor (TCR) recognition rather than increased HLA binding. Collectively, our data suggest that p105–120 is recognized suboptimally by human T cells. This may contribute to the allergenicity of Can f 1.     

Association of HLA class II alleles with sensitization to cow dander Bos d 2, an important occupational allergen

Allergic sensitization results from a complex interaction between genetic and environmental factors. Earlier studies have shown that highly polymorphic HLA genes are associated with a variety of allergies. Several important respiratory allergens belong to the family of lipocalin proteins. These include occupational sensitizers, such as cow Bos d 2 or rat Rat n 1, and prevalent indoor sensitizers, such as dog Can f 1 or cockroach Bla g 4. HLA associations with sensitization to lipocalin allergens are incompletely known. In the present study we have investigated an association between HLA alleles and sensitization to the major cow allergen Bos d 2. The HLA-DR/DQ genotypes of 40 Bos d 2-sensitized subjects having occupational asthma were determined by polymerase chain reaction (PCR) and the results were compared with the genotypes of 151 unrelated Finnish subjects. The frequencies of HLA class II alleles DRB1*0101, DRB1*0404, DQB1*0302, and DQB1*0501 were significantly higher among Bos d 2-sensitized than among control subjects. In addition, the allergic subjects expressed significantly lower frequencies of HLA-DRB1*0301 and DQB1*0201 alleles than did the control subjects. These data suggest that the HLA class II alleles DRB1*0101, DRB1*0404, DQB1*0302, and DQB1*0501, and the haplotypes that include them, are associated with sensitization to the major cow allergen Bos d 2, whereas HLA-DRB1*0301 and DQB1*0201 are dissociated with it. Amino acid analysis provides a biologically plausible explanation for the HLA associations.     

Utilization of fluorescence in situ hybridization with cytokeratin discriminators in TOP2A assessment of chemotherapy-treated patients with breast cancer

Tumor biomarkers increasingly provide information for predicting outcomes with chemotherapeutic regimens (personalized medicine). Topo2A is a DNA helicase targeted by anthracyclines, cytotoxic therapeutics used in both adjuvant and palliative treatments of breast cancer. TOP2A gene amplification/deletion is implicated in response to anthracycline-based chemotherapy. We describe an approach for analyzing formalin-fixed, paraffin-embedded breast tumors on tissue microarrays with TOP2A fluorescence in situ hybridization coupled with cytokeratin immunofluorescence to target tumor cells. Stained tissue from patient specimens was imaged and analyzed using Metafer/Metacyte (Metasystems, Waltham, MA, USA), including customized image classifiers. TOP2A/CEN17 ratios of 2.0 or greater (amplified) and 0.8 or less (deleted) were observed for 10.0% and 6.1% of the patients, respectively. Patient outcomes for adjuvant chemotherapy (cyclophosphamide-epirubicin-fluorouracil, cyclophosphamide-methotrexate-fluorouracil, no chemotherapy) were evaluated. No statistical significance was achieved for clinical end points regarding TOP2A status in anthracycline-treated patients. However, patients with TOP2A aberrations receiving methotrexate-based therapy exhibited a significant decrease in 5-year distant disease-free survival and breast cancer-specific overall survival, especially for patients with TOP2A deletions (disease-free survival: hazard ratio, 5.31 [P = .001], and breast cancer-specific overall survival: hazard ratio, 6.45 [P ≤ .001]). No significant differences were seen in patients included in the no-chemotherapy group. Topo2A protein levels were assessed by immunohistochemistry with no correlative statistical relevance to immunofluorescence/fluorescence in situ hybridization-based prognosis for cyclophosphamide-epirubicin-fluorouracil or cyclophosphamide-methotrexate-fluorouracil groups. Interestingly, aberrant (under)expressing patients in the no-chemotherapy group exhibited better 5-year distant disease-free survival (hazard ratio, 0.39; P = .004), trending toward more favorable breast cancer-specific overall survival (hazard ratio, 0.61; P = .11). Our results indicate a strategy by which fluorescence in situ hybridization scoring targeted to cytokeratin-positive tumor cells may provide a tool for added precision and efficiency in TOP2A evaluation from tumor tissue.     

Effort—reward imbalance,heart rate,and heart rate variability: the cardiovascular risk in young finns study

Background: Work stress indicated by effort—reward imbalance is hypothesized to cause autonomic arousal, which, if prolonged or frequent, could contribute to cardiovascular pathology. However, only limited empirical evidence on this mechanism is available. Purpose: This study examined associations between effort-reward imbalance, heart rate (HR), and heart rate variability (HRV). Method: The participants were 457 women and 406 men (mean age 32.3 years) derived from the population-based Young Finns Study. Effort—reward imbalance was defined as the ratio between effort and reward, higher efforts compared to rewards indicating greater imbalance. Results: In age-adjusted regression models, higher effort-reward imbalance was associated with lower HRV, and lower reward was associated with higher HR among women. These associations were not attenuated after additional adjustments for demographic characteristics and coronary risk factors. No significant associations of effort—reward imbalance or its components with HR and HRV were found in men. Conclusion: Our finding of lower HRV and higher HR in young healthy women with high effort—reward imbalance and low rewards provides evidence of a potential mechanism that may link effort-reward imbalance to the development of coronary heart disease (CHD) in women.     

Temperament, health-related behaviors, and autonomic cardiac regulation: the cardiovascular risk in young Finns study

Temperament, as indicated by Cloninger's psychobiological model predicts coronary heart disease risk, but its association with autonomic cardiac regulation, a potential mediating mechanism, is unclear. We examined the associations between temperament traits and autonomic cardiac regulation in a resting situation in 798 women and 580 men derived from a population-based sample. After adjustment for age and sex, harm avoidance was associated with lower level of high-frequency (HF) variation, root mean square successive differences (RMSSDs), the percentage of successive R–R intervals >50 ms (pNN50) and higher heart rate (HR) (all p ≤ 0.005), suggesting that harm avoidance is related to low parasympathetic activity. Additional adjustments for behavioral factors attenuated these associations more than the adjustment for biological risk factors. Novelty seeking was associated with higher RMSSD (p = 0.007) and pNN50 (p = 0.012) and lower heart rate (p < 0.001). With adjustment for behavioral risk factors, the associations with RMSSD (p = 0.136) and pNN50 (p = 0.236) attenuated to the null, but adjustment for biological risk factors had little effect. Reward dependence and persistence were unrelated to indices of cardiac regulation.     

Arachidonic acid pathway members PLA2G7, HPGD, EPHX2, and CYP4F8 identified as putative novel therapeutic targets in prostate cancer

The arachidonic acid and prostaglandin pathway has been implicated in prostate carcinogenesis, but comprehensive studies of the individual members in this key pathway are lacking. Here, we first conducted a systematic bioinformatic study of the expression of 36 arachidonic acid pathway genes across 9783 human tissue samples. The results showed that the PLA2G7, HPGD, EPHX2, and CYP4F8 genes are highly expressed in prostate cancer. Functional studies using RNA interference in prostate cancer cells indicated that all four genes are also essential for cell growth and survival. Clinical validation confirmed high PLA2G7 expression, especially in ERG oncogene-positive prostate cancers, and its silencing sensitized ERG-positive prostate cancer cells to oxidative stress. HPGD was highly expressed in androgen receptor (AR)-overexpressing advanced tumors, as well as in metastatic prostate cancers. EPHX2 mRNA correlated with AR in primary prostate cancers, and its inhibition in vitro reduced AR signaling and potentiated the effect of antiandrogen flutamide in cultured prostate cancer cells. In summary, we identified four novel putative therapeutic targets with biomarker potential for different subtypes of prostate cancer. In addition, our results indicate that inhibition of these enzymes may be particularly powerful when combined with other treatments, such as androgen deprivation or induction of oxidative stress.