Immune responses to injury and their links to eye disease

The eye is regarded as an immune privileged site. Since the presence of a vasculature would impair vision, the vasculature of the eye is located outside of the central light path. As a result, many regions of the eye evolved mechanisms to deliver immune cells to sites of dysgenesis, injury, or in response to the many age-related pathologies. While the purpose of these immune responses is reparative or protective, cytokines released by immune cells compromise visual acuity by inducing inflammation and fibrosis. The response to traumatic or pathological injury is distinct in different regions of the eye. Age-related diseases impact both the anterior and posterior segment and lead to reduced quality of life and blindness. Here we focus attention on the role that inflammation and fibrosis play in the progression of age-related pathologies of the cornea and the lens as well as in glaucoma, the formation of epiretinal membranes, and in proliferative vitreoretinopathy.

PTTG1 knockdown enhances radiation-induced antitumour immunity in lung adenocarcinoma

AIM

Ionizing radiation (IR) can induce local and systemic antitumour immune responses to some degree and augment immunotherapeutic efficacy. IR may also increase residual tumour cell invasion and elicit immunosuppression in the tumour microenvironment (TME). It remains poorly understand, whether IR leads to immune negative response or invasive capacity increases in lung adenocarcinoma (LAC).

MATERIALS AND METHODS

RNA interference (RNAi) was used to silence pituitary tumour-transforming gene-1 (PTTG1) and SMAD3 expression in LAC cells. A coculture system of tumour cells and PBMCs was constructed. Cells were exposed to different doses (0, 4 and 8 Gy) of X-ray irradiation. Flow cytometric analysis and Transwell assays were applied. An orthotopic Lewis lung cancer (LLC) mouse tumour model was established. Bioluminescence imaging (BLI) was used. LLC tumours were exposed to a single 15 Gy dose of X-ray irradiation.

KEY FINDINGS

PTTG1 knockdown reinforced the inhibitory effect of IR on the invasive ability of A549 cells and enhanced the antitumour T cell immunity induced by IR via the transforming growth factor-β1 (TGF-β1)/SMAD3 pathway. Positive antitumour immune response and immunosuppression were simultaneously triggered by a single 15 Gy dose of local tumour irradiation. PTTG1 knockdown weakened invasive capacity and promoted the immune response balance induced by IR to tilt towards active immunity, which contributed to reduce metastasis and prolonged overall survival (OS) in orthotopic LLC tumour-bearing mouse.

SIGNIFICANCE

Targeted blockade of PTTG1 and the TGF-β1/SMAD3 pathway may ameliorate the immunosuppressive TME and enhance the systemic antitumour immune response induced by a single high-dose IR treatment.

The influences of TGF-β1 upon the human adenocarcinoma cell of lung A549 and cellular immunity

Background

The cellular immunity of lung cancer patients is mainly the immune response of T cells, which plays an important role in tumour cell killing and immune surveillance. Transforming growth factor 1 (TGF-β1) is secreted by tumour cells that can suppress the immune response and is an important group of immune down-regulation factors. Our study aims to investigate the effect of TGF-β1 on the morphology and cellular immune function of A549 and peripheral blood mononuclear cells (PBMCs).

Methods

A549 cell line was cultured, PBMCs were cultured with different concentrations of TGF-β1, and the morphology of A549 cells and PBMCs were seen. The levels of interleukin (IL)-2, IL-4, IL-6, IL-10, IFN-γ, and TNF and the numbers of CD3, CD4, CD8, CD4/CD8, and CD3 CD25 and CD4 CD25 in PBMCs were detected.

Results

During co-culture of A549 with PBMCs, TGF-β1 can induced A549 showing epithelial-to-mesenchymal transition, enhanced its ability of migration and infiltration. Simultaneously, TGF-β1 can depressing the growth and proliferation of PBMCs, inhibiting T-cell activation, and accelerating the PBMCs apoptosis. TGF-β1 can inhibits A549 Th1 related-cytokines, enhance Th2 related-cytokines, cause the disorder of Th1/Th2, resulting in the Th1 cellular dominate immunity decline.

Conclusions

TGF-β1 may affect the secretion of related cytokines, hinder the activation of T lymphocytes, destroy the immune surveillance and killing effect of the body, and thus inhibit the cellular immunity.