Co-Isolation of Cytokines and Exosomes: Implications for Immunomodulation Studies

Exosomes play a vital role in intercellular communication and their immunomodulatory potential have become an important focus in cancer research. Various methods have been developed for the isolation although each method differs in the number and purity of exosomes they yield. In melanoma, tumor-derived exosomes drive immunosuppression within the tumor microenvironment. The co-elution of exosomes and soluble factors such as cytokines during isolation, however, make it difficult to ascertain the contribution of exosome cargo, as soluble cytokines are equally capable of immune suppression. In this review we will expound upon the biological relevance that exosome-associated cytokines possess. Furthermore, we discuss the technical challenges that arise during exosome isolation and what this means for further studies into the TME and in vivo work.

Relationship between serum cytokines receptors and matrix metalloproteinase 9 levels and coronary artery disease

BACKGROUND

The prevalence of coronary artery disease (CAD) is increasing globally, supporting the need for the identification of novel biomarkers. Therefore in the present study, we have explored the association of SIL2A, SIL6R, STNFRI, STNFRII, and MMP9 in CAD patients.

METHODS

Twenty one patients with angiographically defined CAD with more than 50% occlusion, at least, in one coronary artery and twenty healthy subjects (n=20) without the history of cardiovascular symptoms were enrolled. Demographic and biochemical analysis (e.g. Total Cholesterol (TC), Triglyceride (TG), and HDL-C) were measured in all the subjects. The level of cytokines receptor (SIL2A, SIL6R, SIL6R, STNFRI, STNFRII, and matrix metallopeptidase 9 (MMP9) were evaluated.

RESULTS

Our results showed the higher level of MMP9 in patients group compared to the control subjects, while no significant differences were detected for other cytokines. In particular the level of MMP9 was significantly (P=.015) increased from 181.16 ng/mL (95%CI: 112.1-199.2) to 192.0 ng/mL (95%CI: 181.5-265.2). Moreover, the sensitivity and specificity of MMP9 were 95.45% and 45%, respectively, as detected by receiver operating characteristic (ROC) curves.

CONCLUSION

We demonstrate the significant correlation of MMP-9 with CAD with sensitivity of 95.45%, suggesting its role as a biomarker in CAD patients. Further studies in larger population - preferably multicenter setting - are warranted to explore the functional role of this marker in coronary artery disease.

Epstein-Barr virus-specific CD8(+) T lymphocytes from diffuse large B cell lymphoma patients are functionally impaired

Epstein-Barr virus (EBV) is a persistent virus with oncogenic capacity that has been implicated in the development of aggressive B cell lymphomas, primarily in immunosuppressed individuals, although it can be present in immunocompetent individuals. Changes in the function and clonal diversity of T lymphocytes might be implied by viral persistence and lymphoma development. The aim of the present study was to evaluate the frequency, phenotype, function and clonotypical distribution of EBV-specific T cells after peripheral blood stimulation with a virus lysate in newly diagnosed patients with diffuse large B cell lymphoma (DLBCL) aged more than 50 years without prior histories of clinical immunosuppression compared with healthy controls. Our results showed impaired EBV-specific immune responses among DLBCL patients that were associated primarily with decreased numbers of central and effector memory CD8(+) T lymphocytes. In contrast to healthy controls, only a minority of the patients showed CD4(+)/tumour necrosis factor (TNF)-α(+) T cells expressing T cell receptor (TCR)-Vβ17 and CD8(+)/TNF-α(+) T cells with TCR-Vβ5·2, Vβ9 and Vβ18 in response to EBV. Notably, the production of TNF-α was undetectable among TCR-Vβ5·3(+), Vβ11(+), Vβ12(+), Vβ16(+) and Vβ23(+) CD8(+) T cells. In addition, we observed decreased numbers of CD4(+)/TNF-α(+) and CD8(+)/TNF-α(+), CD8(+)/interleukin (IL)-2(+) and CD8(+)/TNF-α(+)/IL-2(+) T lymphocytes in the absence of T cells capable of producing TNF-α, IL-2 and IFN-γ after EBV stimulation simultaneously. Moreover, DLBCL patients displayed higher IL-10 levels both under baseline conditions and after EBV stimulation. These findings were also observed in patients with positive EBV viral loads. Prospective studies including a large number of patients are needed to confirm these findings.

Age-associated Epstein-Barr virus-specific T cell responses in seropositive healthy adults

Epstein-Barr virus (EBV) is present in 95% of the world's adult population. The immune response participates in immune vigilance and persistent infection control, and this condition is maintained by both a good quality (functionality) and quantity of specific T cells throughout life. In the present study, we evaluated EBV-specific CD4(+) and CD8(+) T lymphocyte responses in seropositive healthy individuals younger and older than 50 years of age. The assessment comprised the frequency, phenotype, functionality and clonotypic distribution of T lymphocytes. We found that in both age groups a similar EBV-specific T cell response was found, with overlapping numbers of tumour necrosis factor (TNF)-α(+) T lymphocytes (CD4(+) and CD8(+)) within the memory and effector cell compartments, in addition to monofunctional and multi-functional T cells producing interleukin (IL)-2 and/or interferon (IFN)-γ. However, individuals aged more than 50 years showed significantly higher frequencies of IL-2-producing CD4(+) T lymphocytes in association with greater production of soluble IFN-γ, TNF-α and IL-6 than subjects younger than 50 years. A polyclonal T cell receptor (TCR)-variable beta region (Vβ) repertoire exists in both age groups under basal conditions and in response to EBV; the major TCR families found in TNF-α(+) /CD4(+) T lymphocytes were Vβ1, Vβ2, Vβ17 and Vβ22 in both age groups, and the major TCR family in TNF-α(+) /CD8(+) T cells was Vβ13·1 for individuals younger than 50 years and Vβ9 for individuals aged more than 50 years. Our findings suggest that the EBV-specific T cell response (using a polyclonal stimulation model) is distributed throughout several T cell differentiation compartments in an age-independent manner and includes both monofunctional and multi-functional T lymphocytes.