Seasonal changes of proapoptotic soluble Fas ligand level in allergic rhinitis combined with asthma

Cord blood soluble Fas ligand linked to allergic rhinitis and lung function in seven-year-old children

BACKGROUND

Serum or cord blood soluble Fas ligand (FasL) has been related to asthma, allergic rhinitis, and atopic dermatitis in cross-sectional and short-term follow-up studies. However, the association of cord blood soluble FasL with long-term allergic outcomes has seldom been investigated.

METHODS

The Prediction of Allergies in Taiwanese Children birth cohort study recruited healthy newborns upon delivery. At birth, blood was collected from the umbilical cords of these children, and the cord blood soluble Fas ligand levels were measured. At the age of seven years, the allergic outcome of each child was diagnosed by pediatric allergists and pulmonologists. Tests were conducted to measure the specific immunoglobulin E, fractional exhaled nitric oxide (FeNO), and pulmonary function levels of each child.

RESULTS

Cord blood soluble FasL levels were higher in seven-year-old children with allergic rhinitis (Odds ratio [OR] = 2.41, p = 0.012) and expiratory airway obstruction (the highest forced expiratory volume in 1 second/forced vital capacity < 90%, OR = 2.11, p = 0.022). The FeNO and Dermatophagoides pteronyssinus-specific immunoglobulin E levels of seven-year-old children were positively correlated with cord blood soluble FasL levels (p = 0.006 and 0.02, respectively).

CONCLUSION

In this birth cohort, the cord blood soluble FasL levels were associated with allergic rhinitis, obstructive-type lung function, FeNO, and house dust mite sensitization in 7-year-old children. The cord blood soluble FasL level might be used as a predictor for allergic diseases in children who are 7 years old.

sFasL-The Key to a Riddle: Immune Responses in Aging Lung and Disease

By dint of the aging population and further deepened with the Covid-19 pandemic, lung disease has turned out to be a major cause of worldwide morbidity and mortality. The condition is exacerbated when the immune system further attacks the healthy, rather than the diseased, tissue within the lung. Governed by unremittingly proliferating mesenchymal cells and increased collagen deposition, if inflammation persists, as frequently occurs in aging lungs, the tissue develops tumors and/or turns into scars (fibrosis), with limited regenerative capacity and organ failure. Fas ligand (FasL, a ligand of the Fas cell death receptor) is a key factor in the regulation of these processes. FasL is primarily found in two forms: full length (membrane, or mFasL) and cleaved (soluble, or sFasL). We and others found that T-cells expressing the mFasL retain autoimmune surveillance that controls mesenchymal, as well as tumor cell accumulation following an inflammatory response. However, mesenchymal cells from fibrotic lungs, tumor cells, or cells from immune-privileged sites, resist FasL⁺ T-cell-induced cell death. The mechanisms involved are a counterattack of immune cells by FasL, by releasing a soluble form of FasL that competes with the membrane version, and inhibits their cell death, promoting cell survival. This review focuses on understanding the previously unrecognized role of FasL, and in particular its soluble form, sFasL, in the serum of aged subjects, and its association with the evolution of lung disease, paving the way to new methods of diagnosis and treatment.

Allergen-specific immunotherapy increases plasma gelsolin levels

BACKGROUND

It has been observed that patients with allergic asthma/rhinitis have increased apoptosis of peripheral blood cells. This study was designed to explore the idea that the markers of apoptosis may help predict the response of allergen immunotherapy.

METHODS

The Allergy Department of University Hospital, Malmö, Sweden, recruited a total of 58 young adults (<35 years) with a history of birch pollen/grass pollen-induced allergic rhinitis. Their diagnoses were verified by positive skin-prick tests and the presence of serum-specific immunoglobulin E antibodies toward birch and/or grass pollen. Plasma samples were obtained from 34 patients before the start of immunotherapy and 24 patients after treatment. The control group consisted of 38 nonallergic individuals. The levels of plasma gelsolin, soluble forms of Fas (sFas) and Fas ligand (Fas-L), the chemokine CCL17 (thymus- and activation-regulated chemokine), and tissue inhibitor of metalloprotease (TIMP) 1, were measured by enzyme-linked immunosorbent assay.

RESULTS

In patients receiving immunotherapy plasma gelsolin levels were higher relative to those without immunotherapy (the median level was 23.97 μg/mL [range, 18-35.8 μg/mL] versus 21.2 μg/mL [range, 13.9-29.8 μg/mL]; p = 0.012) and were similar to those of healthy controls (24.7 μg/mL [range, 17.4-35.3 μg/mL]). Plasma levels of sFas, Fas-L, CCL17, and TIMP-1 did not differ between study groups. Only in controls did the plasma gelsolin levels inversely correlate to the levels of soluble Fas.

CONCLUSION

Allergen-specific immunotherapy increases plasma levels of gelsolin, an antioxidant and antiapoptotic protein.

Influence of FAS on murine mast cell maturation

BACKGROUND

FAS has been shown to be involved in the regulation of many immune processes by induction of cellular apoptosis. However, accumulated evidence shows that FAS signaling also exhibits nonapoptotic functions, such as induction of cell proliferation and differentiation. FAS is the only death receptor known to be expressed on murine mast cells (MCs).

OBJECTIVE

To evaluate the role of FAS on murine MC maturation.

METHODS

Mouse bone marrow-derived MCs (BMMCs) or peritoneal MCs were derived from FAS-deficient, FASlpr/lpr, and congenic wild-type strains. The MC degranulation and cytokine release after IgE activation was assessed by measuring β-hexosaminidase, interleukin 13, and tumor necrosis factor α release. Transmission electron microscopy analysis was performed to evaluate the level of BMMC maturation. The surface markers and intracellular preformed mediators were measured as well.

RESULTS

Our data reveal that FAS deficiency has an impact on IgE-dependent activation of BMMCs, resulting in a significant decrease in β-hexosaminidase, interleukin 13, and tumor necrosis factor α release. The total content of preformed mediators (eg, tryptase and β-hexosaminidase) was reduced in BMMCs derived from FAS-deficient mice. We also found that the level of FcεRI in peritoneal mast cells from FAS-deficient mice was significantly diminished. FAS deficiency also influenced the kinetics of BMMC maturation as was revealed by transmission electron microscopy analysis.

CONCLUSION

Our data show that FAS has an impact on the regulation of mouse MC maturation in vitro.