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The pandemic of COVID-19 has caused >5 million deaths in the world. One of the leading causes of the severe form of COVID-19 is the production of massive amounts of proinflammatory cytokines. Epigenetic mechanisms, such as histone/DNA methylation, miRNA, and long noncoding RNA, are known to play important roles in the regulation of inflammation. In this study, we investigated if hospitalized COVID-19 patients exhibit alterations in epigenetic pathways in their PBMCs. We also compared gene expression profiles between healthy controls and COVID-19 patients. Despite individual variations, the expressions of many inflammation-related genes, such as arginase 1 and IL-1 receptor 2, were significantly upregulated in COVID-19 patients. We also found the expressions of coagulation-related genes Von Willebrand factor and protein S were altered in COVID-19 patients. The expression patterns of some genes, such as IL-1 receptor 2, correlated with their histone methylation marks. Pathway analysis indicated that most of those dysregulated genes were in the TGF-β, IL-1b, IL-6, and IL-17 pathways. A targeting pathway revealed that the majority of those altered genes were targets of dexamethasone, which is an approved drug for COVID-19 treatment. We also found that the expression of bone marrow kinase on chromosome X, a member of TEC family kinases, was increased in the PBMCs of COVID-19 patients. Interestingly, some inhibitors of TEC family kinases have been used to treat COVID-19. Overall, this study provides important information toward identifying potential biomarkers and therapeutic targets for COVID-19 disease.

MicroRNAs (miRNAs) are highly conserved, noncoding small RNAs that regulate gene expression, and consequently several important functions including early embryo development, cell cycle, programmed cell death, cell differentiation, and metabolism. While there are no effective treatments available against hepatocellular carcinoma (HCC), some Chinese herbal medicines have been shown to regulate growth, differentiation, invasion, and metastasis of HCC. Many studies have shown that Chinese herbal medicines regulate the expression of miRNAs and this may be associated with their ability to control the development of HCC. In this article, the effects of Chinese herbal medicines on the expression of miRNAs and their functions in the regulation of HCC have been reviewed and discussed. miRNAs such as miRNA-221 and miRNA-222 mediated by Chinese herbal medicines may be good biomarkers and therapeutic targets for HCC.

Endometriosis (EMS), characterized by the presence and growth of functional en do met rial-like tissues outside the uterine cavity, is a common and benign gyneco logical disorder with a poorly understood and somewhat enigmatic etiopathogenesis and pathophysiology. MicroRNAs (miRNAs) are single-stranded 19-25 nucleotide-long RNAs and have an important role in post-transcriptional gene silencing by base pairing with target mRNAs. Recent research has shown that miRNAs and their target mRNAs are differentially expressed in endometriosis and other disorders of the female reproductive system. In this paper, we review the recent progress in understanding the roles of miRNAs in endometriosis, and specific miRNAs as biomarkers and therapeutic targets for endometriosis.

While Post Traumatic Stress Disorder (PTSD) is associated with immune dysfunction, the underlying mechanisms remain unclear. Studies suggest a role for involvement of epigenetic mechanisms and microRNAs (miRNAs). Here, we examined genome-wide histone and DNA methylation in the peripheral blood mononuclear cells (PBMCs) in PTSD. We noted significant differences in histone H3 trimethylation at K4, K9, K27 and K36 sites in PTSD when compared to control. While overall DNA methylation level did not differ significantly between control and PTSD, the promoters of several individual genes (e.g., Interferon gamma (IFNG) and Interleukin (IL)-12B) were differentially methylated. ChIP-seq data revealed that the promoter of IFNG and TBX-21 was associated with the activation marker H3K4me3 in PTSD. The transcript levels of both IFNG and TBX-21 were higher in PTSD correlating well with the altered methylation patterns. Furthermore, PTSD patients showed increased expression of IL-12 in their PBMCs. Analysis of both histone and DNA methylation markers suggested that the expression of IL-12 was also possibly activated through epigenetic modification. Knockdown of lysine (K)-specific demethylase 5B (KDM5B), or inhibition of DNA (Cytosine-5-)-methyltransferase 1 (DNMT1) caused up-regulation of IL-12. Furthermore, the expression of these cytokines was also regulated by miRNAs. Our miRNA microarray identified many down regulated miRNAs in PTSD that are predicted to target IFNG and IL-12. Consequently, we showed that up-regulation of hsa-miR-193a-5p could decrease the expression of IL-12. Overall, the current study demonstrated that the elevated expression of pro-inflammatory cytokines in PTSD patients might be regulated by multiple epigenetic mechanisms and miRNAs.

MicroRNAs (miRNAs) are single-stranded 19-25 nucleotide-long RNAs and have an important role in post-transcriptional gene silencing. It has been demonstrated that miRNAs are dysregulated in patients with multiple sclerosis (MS). For instance, miR-21, miR-142-3p, miR-146a, miR-146b, miR-155 and miR-326 were up-regulated in both peripheral blood mononuclear cells (PBMCs) and brain white matter lesions from MS patients and mouse model as well. These up-regulated miRNAs may be used as a signature for MS and play critical roles in MS pathogenesis. Moreover, miR-15a, miR-19a, miR-22, miR-210 and miR-223 were up-regulated in both regulatory T cells (Tregs) and other samples such as plasma, blood cells, PBMCs and brain white matter tissues from MS patients, suggesting that these up-regulated miRNAs and Tregs may also play a role in MS pathogenesis. Contrarily, other miRNAs such as miR-15a, miR-15b, miR-181c and miR-328 were down-regulated in MS. Drugs such as interferon-β and glatiramer acetate for MS treatment may regulate miRNA expression and thus have benefits for MS patients. The dysregulated miRNAs such as miR-155 and miR-326 may be used as diagnostic markers and therapeutic targets for MS.

Post-traumatic stress disorder patients experience chronic systemic inflammation. However, the molecular pathways involved and mechanisms regulating the expression of genes involved in inflammatory pathways in PTSD are reported inadequately. Through RNA sequencing and miRNA microarray, we identified 326 genes and 190 miRNAs that were significantly different in their expression levels in the PBMCs of PTSD patients. Expression pairing of the differentially expressed genes and miRNAs indicated an inverse relationship in their expression. Functional analysis of the differentially expressed genes indicated their involvement in the canonical pathways specific to immune system biology. DNA methylation analysis of differentially expressed genes also showed a gradual trend towards differences between control and PTSD patients, again indicating a possible role of this epigenetic mechanism in PTSD inflammation. Overall, combining data from the three techniques provided a holistic view of several pathways in which the differentially expressed genes were impacted through epigenetic mechanisms, in PTSD. Thus, analysis combining data from RNA-Seq, miRNA array and DNA methylation, can provide key evidence about dysregulated pathways and the controlling mechanism in PTSD. Most importantly, the present study provides further evidence that inflammation in PTSD could be epigenetically regulated.

Malignancies arising from retrovirally transduced hematopoietic stem cells have been reported in animal models and human gene therapy trials. Whether mature lymphocytes are susceptible to insertional mutagenesis is unknown. We have characterized a primary human CD8+ T-cell clone, which exhibited logarithmic ex vivo growth in the absence of exogenous cytokine support for more than 1 year after transduction with a murine leukemia virus–based vector encoding the T-cell growth factor IL-15. Phenotypically, the clone was CD28−, CD45RA−, CD45RO+, and CD62L−, a profile consistent with effector memory T lymphocytes. After gene transfer with tumor-antigen–specific T-cell receptors, the clone secreted IFN-γ upon encountering tumor targets, providing further evidence that they derived from mature lymphocytes. Gene-expression analyses revealed no evidence of insertional activation of genes flanking the retroviral insertion sites. The clone exhibited constitutive telomerase activity, and the presence of autocrine loop was suggested by impaired cell proliferation following knockdown of IL-15Rα expression. The generation of this cell line suggests that nonphysiologic expression of IL-15 can result in the long-term in vitro growth of mature human T lymphocytes. The cytokine-independent growth of this line was a rare event that has not been observed in other IL-15 vector transduction experiments or with any other integrating vector system. It does not appear that the retroviral vector integration sites played a role in the continuous growth of this cell clone, but this remains under investigation.

Multiple sclerosis (MS) is not only an autoimmune disease in which autoreactive immune cells against myelin damage axons and nerves in the central nervous system, but also a neurodegenerative disease, in which progressive loss of structure and function of neurons occurs. The mechanisms of MS pathogenesis have not been fully understood. It has been reported that miRNAs may play a critical role in MS pathogenesis. In this review, we have extensively discussed the alterations in the expression of miRNAs detected in patients with MS. The dysregulated miRNAs have been shown to be associated with the pathogenesis of MS. We suggest that such dysregulated miRNAs may potentially be used as biomarkers in the diagnosis of MS, to discover new therapeutic targets for MS treatment, and to predict prognostic markers in responses to MS treatment.

Recent studies have indicated that adoptive immunotherapy with autologous antitumor tumor-infiltrating lymphocytes (TILs) following nonmyeloablative chemotherapy mediates tumor regression in ∼50% of treated patients with metastatic melanoma, and that tumor regression is correlated with the degree of persistence of adoptively transferred T cells in peripheral blood. These findings, which suggested that the proliferative potential of transferred T cells may play a role in clinical responses, led to the current studies in which telomere length as well as phenotypic markers expressed on the administered TILs were examined. TILs that were associated with objective clinical responses following adoptive transfer possessed a mean telomere length of 6.3 kb, whereas TILs that were not associated with significant clinical responses were significantly shorter, averaging 4.9 kb (p < 0.01). Furthermore, individual TIL-derived T cell clonotypes that persisted in vivo following adoptive cell transfer possessed telomeres that were longer than telomeres of T cell clonotypes that failed to persist (6.2 vs 4.5 kb, respectively; p < 0.001). Expression of the costimulatory molecule CD28 also appeared to be associated with long telomeres and T cell persistence. These results, indicating that the telomere length of transferred lymphocytes correlated with in vivo T cell persistence following adoptive transfer, and coupled with the previous observation that T cell persistence was associated with clinical responses in this adoptive immunotherapy trial, suggest that telomere length and the proliferative potential of the transferred T cells may play a significant role in mediating response to adoptive immunotherapy.

The authors recently reported that adoptive immunotherapy with autologous tumor-reactive tumor infiltrating lymphocytes (TILs) immediately following a conditioning nonmyeloablative chemotherapy regimen resulted in an enhanced clinical response rate in patients with metastatic melanoma. These observations led to the current studies, which are focused on a detailed analysis of the T-cell antigen reactivity as well as the in vivo persistence of T cells in melanoma patient 2098, who experienced a complete regression of all metastatic lesions in lungs and soft tissues following therapy. Screening of an autologous tumor cell cDNA library using transferred TILs resulted in the identification of novel mutated growth arrest-specific gene 7 (GAS7) and glyceral-dehyde-3-phosphate dehydrogenase (GAPDH) gene transcripts. Direct sequence analysis of the expressed T-cell receptor beta chain variable regions showed that the transferred TILs contained multiple T-cell clonotypes, at least six of which persisted in peripheral blood for a month or more following transfer. The persistent T cells recognized both the mutated GAS7 and GAPDH. These persistent tumor-reactive T-cell clones were detected in tumor cell samples obtained from the patient following adoptive cell transfer and appeared to be represented at higher levels in the tumor sample obtained 1 month following transfer than in the peripheral blood obtained at the same time. Overall, these results indicate that multiple tumor-reactive T cells can persist in the peripheral blood and at the tumor site for prolonged times following adoptive transfer and thus may be responsible for the complete tumor regression in this patient.

In recent clinical trials in patients with metastatic melanoma, adoptive transfer of tumor-reactive lymphocytes mediated the regression of metastatic tumor deposits. To better understand the role of individual T cell clones in mediating tumor regression, a 5′ RACE technique was used to determine the distribution of TCR β-chain V region sequences expressed in the transferred cells as well as in tumor samples and circulating lymphocytes from melanoma patients following adoptive cell transfer. We found that dominant T cell clones were present in the in vitro-expanded and transferred tumor-infiltrating lymphocyte samples and certain T cell clones including the dominant T cell clones persisted at relatively high levels in the peripheral blood of the patients that demonstrated clinical responses to adoptive immunotherapy. However, these dominant clones were either undetected or present at a very low level in the resected tumor samples used for tumor-infiltrating lymphocyte generation. These data demonstrated that there was selective growth and survival, both in vitro and in vivo, of individual T cell clones from a relatively small number of T cells in the original tumor samples. These results suggest that the persistent T cell clones played an active role in mediating tumor regression and that 5′ RACE analysis may provide an important tool for the analysis of the role of individual T cell clones in mediating tumor regression. A similar analysis may also be useful for monitoring autoimmune responses.

Sepsis is a major cause of death worldwide. It triggers systemic inflammation, the role of which remains unclear. In the current study, we investigated the induction of microRNA (miRNA) during sepsis and their role in the regulation of inflammation. Patients, on days 1 and 5 following sepsis diagnosis, had reduced T cells but elevated monocytes. Plasma levels of IL-6, IL-8, IL-10 and MCP-1 dramatically increased in sepsis patients on day 1. T cells from sepsis patients differentiated primarily into Th2 cells, whereas regulatory T cells decreased. Analysis of 1163 miRNAs from PBMCs revealed that miR-182, miR-143, miR-145, miR-146a, miR-150, and miR-155 were dysregulated in sepsis patients. miR-146a downregulation correlated with increased IL-6 expression and monocyte proliferation. Bioinformatics analysis uncovered the immunological associations of dysregulated miRNAs with clinical disease. The current study demonstrates that miRNA dysregulation correlates with clinical manifestations and inflammation, and therefore remains a potential therapeutic target against sepsis.

RNA helicase II/Gu (RH II/Gu) is a nucleolar antigen originally identified using an autoimmune serum from a patient with watermelon stomach. A later report showed that anti-RH II/Gu autoantibodies were also present at low frequency in connective tissue disease (CTD) patients who did not show any symptoms suggestive of a watermelon stomach lesion. In an attempt to understand the relationship between watermelon stomach, also called gastric antral vascular ectasia (GAVE), and autoimmune disorder, we identified the antigenic sites recognized by these autoantibodies. Serum Gu uniquely recognized epitopes at amino acids 646-748 of RH II/Gu and all four CTD patient sera recognized antigenic sites within amino acids 1-173. Anti-RH II/Gu serum produced by immunizing rabbit with recombinant human RH II/Gu protein bound to the same antigenic sites recognized by the CTD patient sera, but it did not recognize the serum Gu epitopes. Results are also presented showing the use of these anti-RH II/Gu antibodies in the analysis of the evolutionary conservation of RH II/Gu in human, monkey and mouse.

Objective To determine the impact of endometriotic lesion removal on local and systemic inflammation. Design Multiplex cytokine analysis on samples from endometriosis patients before surgery, 2 weeks after surgery, and 3 months after surgery. Setting Academic teaching hospital and university. Patient(s) A total of 43 endometriosis patients before and after excision of lesions by means of laparoscopic surgery, and 25 normal women. Intervention(s) None. Main Outcome Measure(s) Plasma, eutopic and ectopic tissue, and peritoneal fluid cytokine levels. Result(s) Compared with presurgery plasma samples, levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL) 2, IL-8, and IL-10 decreased significantly by 2 weeks after surgery in endometriosis patients. Interestingly, levels began to rise at 3 months after surgery in most cases. In tissue, levels of GM-CSF and IL-15 were lower in eutopic tissue, while levels of basic fibroblast growth factor, interferon-inducible protein 10, IL-1 receptor antagonist, granulocyte colony–stimulating factor, macrophage inflammatory protein 1β, IL-7, and IL-5 were higher in eutopic than in ectopic tissue. In peritoneal fluid, levels of IL-5 and IL-12 were higher in early versus advanced stages of endometriosis. Compared with normal women, plasma from endometriosis patients had higher levels of inflammatory cytokines. Conclusion(s) Endometriotic lesion removal significantly alters the inflammatory profile both locally and systemically in women with endometriosis. Our findings indicate that ectopic lesions are the major drivers of systemic inflammation in endometriosis. The transitory nature of the change may reflect the recurrence of the condition and the influence of systemic factors in its onset.

Multifunctional abietane-based polymer nanogels were fabricated for label-free cell imaging and drug delivery. The self-fluorescent abietane as the framework of carriers enables the imaging without the need for external fluorescent probes, while abietane-based nanogels exhibit low in vitro cytotoxicity.

CD44 is a cell-surface glycoprotein involved in many cellular functions including lymphocyte activation, recirculation and homing, hematopoiesis and tumor metastasis, suggesting that CD44 may play an important role in breast cancer development. In this study, we examined whether CD44 exon 2 polymorphisms are associated with increased susceptibility to breast cancer. Direct nucleotide sequencing analysis showed that multiple single nucleotide polymorphisms were present in the CD44 exon 2 coding region in female patients with breast cancer. There was no significant difference in the frequency of any one single nucleotide polymorphism in the CD44 exon 2 coding region between patients with breast cancer and normal donors. However, CD44 polymorphisms in the CD44 exon 2 coding region were identified in approximately 40% of patients with breast cancer, which was significantly higher than in normal donors (odds ratio, 9.34; 95% confidence interval = 2.58-33.82; P < 0.0001). The Wilcoxon-Mann-Whitney test analysis showed that the patients with the CD44 polymorphisms in CD44 exon 2 coding sequence had breast cancer at earlier ages, 49 ± 3 versus 62 ± 2 years (P < 0.0005), and larger tumor burdens (4.9 ± 1.22 vs. 1.6 ± 0.15 mm, P < 0.01) at the time of diagnosis. Interestingly, African-American female patients having the CD44 polymorphisms in CD44 exon 2 coding sequence were diagnosed with breast cancer at very young age (41 ± 2 years). Our results show that CD44 exon 2 polymorphisms are associated with breast cancer development, and such analysis may be effectively used in the evaluation of risk, prediction of cancer, prevention, diagnosis, and epidemiological studies of breast cancer.

Adoptive cell therapy (ACT) with tumor reactive lymphocytes in patients with refractory melanoma can result in tumor regression and prolonged survival. Generating tumor reactive lymphocyte cultures is technically difficult and resource intensive; these limitations have restricted the widespread application of ACT. Tumor infiltrating lymphocytes (TIL) from melanoma contain tumor antigen reactive cells. The “standard” method for producing TIL cultures for clinical administration requires extended in vitro expansion in interleukin-2, then identification of tumor reactive cells by immunological assays. We show here that limitations in reagents and methods during screening under-represent the actual reactivity of TIL cultures. Furthermore, the extended culture times necessitated by the screening assays resulted in telomere shortening and reduced expression of CD27 and CD28 in the TIL cultures, properties that our prior studies showed are correlated within vivo persistence and clinical response. We have thus developed an alternative “young” TIL method that demonstrated superior in vitro attributes compared with standard TIL. This approach utilizes the entire resected tumor to rapidly expand TIL for administration without in vitro testing for tumor recognition. Our observations suggest that younger TIL can have an undetermined but high level of antigen reactivity, and other advantageous attributes such as long telomeres and high levels of CD27 and CD28. We suggest that minimally cultured, unselected lymphocytes represent an alternative strategy for generating TIL cultures suitable for use in ACT therapy that, if effective in vivo, may facilitate the widespread application of this approach to a broader population of patients with melanoma.

Transfer of autologous tumor-specific tumor infiltrating lymphocytes (TILs) in adoptive immunotherapy can mediate the regression of tumor in patients with metastatic melanoma. In this procedure, TILs from resected tumors are expanded in vitro, then administered to patients and further stimulated to proliferate in vivo by the administration of high dose IL-2. After in vitro expansion, TILs are often dominated by a few specific clonotypes, and recently it was reported that the persistence in vivo of one or more of these clonotypes correlated with positive therapeutic response. We and others have previously shown that repeated in vitro stimulation and clonal expansion of normal human T lymphocytes results in progressive decrease in telomerase activity and shortening of telomeres, ultimately resulting in replicative senescence. In the studies reported here, we therefore compared telomerase activity and telomere length in persistent and nonpersistent TIL clonotypes before transfer in vivo, and found a correlation between telomere length and clonal persistence. We also observed that TILs proliferate extensively in vivo in the days after transfer, but fail to induce substantial telomerase activity, and undergo rapid decreases in telomere length within days after transfer. Thus, in vivo loss of telomeres by clonotypes that have the shortest telomeres at the time of administration may drive these clones to replicative senescence, whereas cells with longer telomeres are able to persist and mediate antitumor effects. These findings are relevant both to predicting effectiveness of adoptive immunotherapy and in deriving strategies for improving effectiveness by sustaining telomere length.

Mitochondrial DNA (mtDNA) is highly susceptible to mutations due to the low level of DNA repair and the presence of a high level of reactive oxygen species in the organelle. Although mtDNA mutations have been implicated in degenerating diseases, aging, and cancer, very little is known about the role of T cells in immunosurveillance for mtDNA aberrations. Here, we describe T-cell recognition of a peptide translated from an alternative open reading frame of the mitochondrial cytochrome b (cyt b) gene in melanoma cells established from a patient. To understand how the cyt b gene is transcribed and translated in tumor cells, we found that cyt b–specific CD4+ T cells only recognized protein fractions derived from cytoplasm and not from mitochondria. However, T-cell recognition of tumor cells could be inhibited by treatment of tumor cells with rhodamine 6G inhibitor, which depletes mitochondria. These findings suggest that cyt b mRNA is leaked out of the mitochondria and then translated in the cytoplasm for presentation to CD4+ T cells. The cyt b cDNAs from this patient contain highly heteroplasmic transition mutations compared with control cell lines, suggesting a compromise of mitochondrial integrity that may have contributed to melanoma induction or progression. These findings provide the first example of a mitochondrial immune target for CD4+ T cells and therefore have implications for the immunosurveillance of mitochondrial aberrations in cancer patients. (Cancer Res 2006; 66(11): 5919-26)

Breast cancer is a leading cause of cancer-related deaths in women worldwide. Although tumorectomy, radiotherapy, chemotherapy and hormone replacement therapy have been used for the treatment of breast cancer, there is no effective therapy for patients with invasive and metastatic breast cancer. Immunotherapy may be proved effective in treating patients with advanced breast cancer. Breast cancer immunotherapy includes antibody based immunotherapy, cancer vaccine immunotherapy, adoptive T cell transfer immunotherapy and T cell receptor gene transfer immunotherapy. Antibody based immunotherapy such as the monoclonal antibody against HER-2/neu (trastuzumab) is successfully used in the treatment of breast cancer patients with over-expressed HER-2/neu, however, HER-2/neu is over-expressed only in 25-30% of breast cancer patients. Cancer vaccine immunotherapy is a promising method to treat cancer patients. Cancer vaccines can be used to induce specific anti-tumor immunity in breast cancer patients, but cannot induce objective tumor regression. Adoptive T cell transfer immunotherapy is an effective method in the treatment of melanoma patients. Recent advances in anti-tumor T cell generation ex vivo and limited clinical trial data have made the feasibility of adoptive T cell transfer immunotherapy in the treatment of breast cancer patients. T cell receptor gene transfer can redirect the specificity of T cells. Chimeric receptor, scFv(anti-HER-2/neu)/zeta receptor, was successfully used to redirect cytotoxic T lymphocyte hybridoma cells to obtain anti-HER-2/neu positive tumor cells, suggesting the feasibility of treatment of breast cancer patients with T cell receptor gene transfer immunotherapy. Clinical trials will approve that immunotherapy is an effective method to cure breast cancer disease in the near future.

The lack of persistence of transferred autologous mature lymphocytes in humans has been a major limitation to the application of effective cell transfer therapies. The results of a pilot clinical trial in 13 patients with metastatic melanoma suggested that conditioning with nonmyeloablative chemotherapy before adoptive transfer of activated tumor-reactive T cells enhances tumor regression and increases the overall rates of objective clinical responses. The present report examines the relationship between T cell persistence and tumor regression through analysis of the TCR β-chain V region gene products expressed in samples obtained from 25 patients treated with this protocol. Sequence analysis demonstrated that there was a significant correlation between tumor regression and the degree of persistence in peripheral blood of adoptively transferred T cell clones, suggesting that inadequate T cell persistence may represent a major factor limiting responses to adoptive immunotherapy.

While the immunological dysfunction in combat Veterans with post-traumatic stress disorder (PTSD) has been well documented, the precise mechanisms remain unclear. The current study evaluated the role of microRNA (miR) in immunological dysfunction associated with PTSD. The presence of peripheral blood mononuclear cells (PBMC) and various lymphocyte subsets in blood collected from PTSD patients were analyzed. Our studies demonstrated that the numbers of both PBMC and various lymphocyte subsets increased significantly in PTSD patients. When T cells were further analyzed, the percentage of Th1 cells and Th17 cells increased, regulatory T cells(Tregs) decreased, while Th2 cells remained unaltered in PTSD patients. These data correlated with increased plasma levels of IFN-γ and IL-17 while IL-4 showed no significant change. The increase in PBMC counts, Th1 and Th17 cells seen in PTSD patients correlated with the clinical scores. High-throughput analysis of PBMCs for 1163 miRs showed that the expression of a significant number of miRs was altered in PTSD patients. Pathway analysis of dysregulated miRs seen in PTSD patients revealed relationship between selected miRNAs and genes that showed direct/indirect role in immunological signaling pathways consistent with the immunological changes seen in these patients. Of interest was the down-regulation of miR-125a in PTSD, which specifically targeted IFN-γ production. Together, the current study demonstrates for the first time that PTSD was associated with significant alterations in miRNAs, which may promote pro-inflammatory cytokine profile. Such epigenetic events may provide useful tools to identify potential biomarkers for diagnosis, and facilitate therapy of PTSD.