IL-10 enhances promoter activity of ILT4 gene and up-regulates its expression in THP-1 cells

Inhibitory receptor immunoglobulin-like transcript 4 was highly expressed in primary ductal and lobular breast cancer and significantly correlated with IL-10

BACKGROUND

Immunoglobulin-like transcript 4 (ILT4) is an inhibitory molecule involved in immune response and has recently been identified to be strongly inducible by IL-10. The aim of the present study was to examine the associations of ILT4 expression with clinicopathological characteristics and IL-10 expression in primary ductal and lobular breast cancer.

METHODS

We studied the expression of ILT4 in 4 cancer cell lines, 117 primary tumor tissues and 97 metastatic lymph nodes from patients with primary ductal and lobular breast cancer by reverse transcription-polymerase chain reaction, western blot or immunohistochemistry analysis. Additionally, IL-10 expression was also investigated using immunohistochemistry in primary tumor tissues. Then the relationship between ILT4 expression and clinicopathological characteristics/IL-10 expression was evaluated.

RESULTS

ILT4 was highly expressed in all 4 human breast cancer cell lines on both mRNA and protein levels. In primary tumor tissues, ILT4 or IL-10 was expressed in the cell membrane, cytoplasm, or both; the positive rate of ILT4 and IL-10 expression was 60.7% (71/117) and 80.34% (94/117), respectively. ILT4 level was significantly correlated with IL-10 (r =0.577; p<0.01). Furthermore, the expression of ILT4 or IL-10 was associated with less number of Tumor Infiltrating Lymphocytes (TILs) (p=0.004 and 0.018, respectively) and more lymph node metastasis (p=0.046 and 0.035, respectively).

CONCLUSION

Our data demonstrated the association of ILT4 and IL-10 expression in human breast cancer, suggesting their important roles in immune dysfunction and lymph node metastases.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1692652692107916.

Cyclosporine induces up-regulation of immunoglobulin-like transcripts 3 and 4 expression on and activity of NKL cells

BACKGROUND

Immunoglobulin-like transcripts (ILTs), which belong to a kind of receptor family discovered recently, are differentially expressed on myeloid and lymphoid cells. Most of them play important roles to regulate human immune responses by interacting with ligands. Cyclosporine (CsA) is frequently used to prevent graft-versus-host disease and treat autoimmune diseases. There are some studies about the effects of CsA on various human immunologic reactions, but its impact on ILT3 and ILT4 expression on natural killer (NK) cells is less well understood.

METHODS

An NKL cell line was exposed to CsA (5, 10, 15, or 20 mg/L) for 12, 24, or 36 hours before real-time quantitative polymerase chain reaction and flow cytometry were used to detect alterations in ILT3 and ILT4 mRNA and protein expressions. NKL cells treated for 36 hours with or without CsA (15 mg/L) and then coincubated with BGC-823 or JEG-3 cells, in cytolytic and proliferative systems measured by Thiazoyl blue tetrazolium bromide assays.

RESULTS

After CsA treatment both RNA and protein levels of ILT3 and ILT4 on NKL cells were increased for 12, 24, or 36 hours. CsA at various concentrations inhibited the proliferation of NKL cells to varying degrees; at 36 hours CsA (15 mg/L) showed greater effects on ILT3 and ILT4 expression and less influence on NKL growth. The ability of NKL cells primed with CsA (15 mg/L) for 36 hours to kill tumor cells was decreased markedly.

CONCLUSIONS

CsA up-regulated the expression of ILT3 and ILT4 on NKL cells, which influenced their cytotoxicity against tumor cells with different expression of HLA-G and proliferation of NKL cells.

Expression of immunoglobulin-like transcript (ILT)2 and ILT3 in human gastric cancer and its clinical significance

Immune inhibitory receptors play an important role in organ transplantation, autoimmune diseases and cancers. Immunoglobulin-like transcript (ILT)2 and ILT3 belong to the inhibitory receptors of the ILT family, which have been reported to regulate a broad range of cellular functions involved in the immune response. They contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which are related to immune regulation. Although ILT receptors have been studied in dendritic cells (DCs), T cells, NK cells and other cell types, the expression and clinical significance of ILT2 and ILT3 in gastric cancer have yet to be elucidated. Here, the expression of ILT2 and ILT3 in gastric cancer cell lines and pathologic tissues, as well as their effects on the cytotoxicity of NK92MI against the gastric cancer cell lines MKNI with ILT2^lowILT3^low and HGC-27 with ILT2^highILT3^high were detected. The results suggest that ILT2 and ILT3 are expressed with diverse degrees in gastric cancer cells and tissues, and the expression of ILT2 is related with differentiation and size of tumors. Furthermore, the cytotoxic activity of NK92MI against the MKNI cell line was stronger than that against HGC-27. This study indicates that ILT2 and ILT3 play a key role in gastric cancer immune escape, and ILT2 may be a new target in the clinical diagnosis and treatment of gastric cancer.