Peripheral Blood T-cell Research Articles

Lymphocyte homeostasis is maintained in perinatally HIV-infected patients after three decades of life

BackgroundWhile immunosenescence, defined as reduced production of new lymphocytes, restriction of T-cell receptor repertoire and telomeres shortening, has been extensively evaluated in HIV-infected children and adults, no data about these parameters are available in perinatally-infected patients with very long-lasting HIV infection.MethodsWe compared thymic and bone marrow output, telomere length (measured by Real-Time PCR) and T-cell receptor repertoire (determined by spectratyping) of 21 perinatally HIV-infected subjects (with a median of 27 years of infection) with those of 19 age-matched non-perinatally HIV-infected patients and 40 healthy controls. All patients received a combined antiretroviral therapy.ResultsWhile thymic and bone marrow output were not different among the analyzed groups, telomere length in peripheral blood cells and T-cell receptor diversity were significantly lower in HIV-perinatally and non-perinatally infected individuals compared to healthy controls.ConclusionsIn HIV-infected subjects, a normal thymic output together with a reduced telomere length and a restricted T-cell receptor repertoire could be explained by the shift of newly produced cells into memory subsets. This phenomenon may allow to control viral infection and maintain peripheral homeostasis.

1303P - Tissue-based activation of mucosal-associated invariant T (MAIT) cells in combination ipilimumab and nivolumab checkpoint inhibitor (CI) colitis

BackgroundUp to 44% of patients receiving combination ipilimumab and nivolumab develop checkpoint-inhibitor-(CI) colitis, however its molecular pathogenesis is poorly understood. We aimed to characterise peripheral blood and gut mononuclear cells (PBMC; GMNC) in patients with CI-colitis and controls to gain insights into disease aetiology. We were particularly interested in activated, memory, gut-homing CD8+ T-cells and also the innate-like mucosal-associated invariant T (MAIT) cells that play important roles in mucosal immunity. MethodsIn Cohort I PBMC from patients with CI-colitis (N=9) were compared with those from patients who received CI with no adverse-events (CI-controls; N=11), patients with active ulcerative colitis (UC; N=6) and Healthy Volunteers (N=16). PBMC findings were tested in a second cohort (Cohort II; IN-Colitis N=15; IN-NAE=9). GMNC were isolated in Cohort III (IN-colitis N=5; IN-controls N=5; UC N=6; Healthy Volunteers N=6). Flow-cytometric analysis was used throughout. ResultsCI-colitis patients had low circulating MAIT cells compared with CI-controls at baseline in Cohort I. Low levels of circulating MAIT cells in both CI-colitis and CI-controls (compared to Healthy Volunteers) were found in Cohort II. CI-treated patients had high levels of activated-memory T-cells in peripheral blood (CD8+>CD4+) that included a gut-homing population, regardless of the development of colitis. However, activation of circulating MAIT cells was not evident. In gut tissue there was elevation of activated, granzyme-B+ MAIT cells in CI-colitis compared with CI-controls. CI-colitis was characterised by an activated-memory CD8+ lymphocytosis. ConclusionsMelanoma patients can have low baseline circulating MAIT cells. In one cohort this associated with CI-colitis. In tissue, activated MAIT cells were elevated in CI-colitis. Further work is needed to determine which immune populations are useful for the prediction and prognostication of CI-colitis, and if MAIT cells contribute to tissue damage or repair. Legal entity responsible for the studyThe authors. FundingCelgene. DisclosureS.C. Sasson: Research grant / Funding (institution): Celgene. V.T.F. Cheung: Speaker Bureau / Expert testimony: Janssen. G.V. Long: Advisory / Consultancy: Aduro; Advisory / Consultancy: Amgen; Advisory / Consultancy: BMS; Advisory / Consultancy: Merck MSD; Advisory / Consultancy: Mass-Array; Advisory / Consultancy: Novartis; Advisory / Consultancy: Pierre Fabre; Advisory / Consultancy: Roche. M.R. Middleton: Advisory / Consultancy: Amgen; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: BMS; Advisory / Consultancy: Eisai; Advisory / Consultancy: Lilli; Advisory / Consultancy: Merck; Advisory / Consultancy: Millenium; Advisory / Consultancy: Novartis; Advisory / Consultancy: Physiomics; Advisory / Consultancy: Rignotec; Advisory / Consultancy: Roche. O. Brain: Speaker Bureau / Expert testimony: BMS; Research grant / Funding (institution): Celgene. All other authors have declared no conflicts of interest.

Adoptive immunotherapy with autologous T-cell infusions reduces opioid requirements in advanced cancer patients

Relief of cancer-related pain remains challenging despite the availability of a range of opioid and nonopioid medications. Animal models demonstrate that T lymphocytes may mediate analgesia by producing endogenous opioids, but definitive clinical data are limited. Transfer of ex vivo adoptive cellular therapy (ACT) is being tested as an anticancer therapy. We retrospectively reviewed the medical charts of 357 patients with various malignancies who received 3 intravenous infusions of autologous cytokine-activated T-cell-enriched products. Among these were 55 patients who required opioids for moderate or severe cancer-related pain. Opioid dosage and cancer pain score were recorded daily for 2 consecutive weeks before and 2 weeks after the ACT infusions. The average oral morphine equivalent doses and cancer pain scores were significantly decreased after the ACT infusions. The proportion of patients with breakthrough pain also declined. Moreover, higher frequencies of expanded CD3, CD3/CD4, and CD3/CD8 T cells within the ACT product were associated with favorable analgesic effects. Transient elevations in CD3 and CD3/CD8T-cell subpopulations and decreases in CD4CD25 Treg were observed in patients' blood after the ACT. In conclusion, ACT was capable of reducing cancer pain severity and opioid consumption and favorably modulating peripheral blood T-cell populations.

T Cell Transcriptional Profiling and Immunophenotyping Uncover LAG3 as a Potential Significant Target of Immune Modulation in Multiple Myeloma.

Autologous stem cell transplant (ASCT) is the standard of care for patients with multiple myeloma (MM). The clinical significance of peripheral blood T lymphocyte (PBTL) immunologic changes associated with ASCT is poorly understood. Here we evaluated T cell transcriptional messenger RNA profiles and immunophenotypes to correlate immunologic senescence, exhaustion, and anergy with clinical endpoints in a cohort of patients with MM undergoing ASCT. ASCT induced global transcriptional T cell changes and altered molecular levels of markers of T cell subtypes, T cell activation, and exhaustion. These included reduced CD4/CD8 ratio, skewing toward the Th1 subset, reduced expression of costimulatory receptors CD27 and CD28, heightened T cell activation, and increased expression of immune modulatory molecules LAG3 and PD1. Multicolor flow cytometry experiments confirmed altered circulating CD4 and CD8 subsets and skewing toward differentiated effector cells. Moreover, ASCT promoted an exhausted immunophenotype in CD3+CD4+ subsets and a senescent immunophenotype in CD3+CD8+ subsets. Subset-specific altered expression was also seen for surface molecules with immunomodulatory function. ASCT affected soluble levels of molecules with immunomodulatory function by increasing plasma HVEM and TIM3. High molecular LAG3 level was associated with inferior event-free survival post-ASCT (hazard ratio = 5.44; confidence interval, 1.92 to 15.46; P = .001; adjusted P [controlling for false discovery rate] = .038). Using a comprehensive evaluation of PBTLs on a molecular and phenotypic level, we have identified that ASCT induces global T cell alterations with CD4 and CD8 subset-specific changes. Moreover, LAG3 emerged as an early biomarker of adverse events post-ASCT. These findings will support the development of treatment strategies targeting immune defects in MM to augment or restore T cell responses.

Peripheral PD-1+CD56+ T-cell frequencies correlate with outcome in stage IV melanoma under PD-1 blockade

Immune checkpoint blockade with anti-PD-1 antibodies is showing great promise for patients with metastatic melanoma and other malignancies, but despite good responses by some patients who achieve partial or complete regression, many others still do not respond. Here, we sought peripheral blood T-cell biomarker candidates predicting treatment outcome in 75 stage IV melanoma patients treated with anti-PD-1 antibodies. We investigated associations with clinical response, progression-free survival (PFS) and overall survival (OS). Univariate analysis of potential biological confounders and known biomarkers, and a multivariate model, was used to determine statistical independence of associations between candidate biomarkers and clinical outcomes. We found that a lower than median frequency of peripheral PD-1+CD56+ T-cells was associated with longer OS (p = 0.004), PFS (p = 0.041) and superior clinical benefit (p = 0.009). However, neither frequencies of CD56-CD4+ nor CD56-CD8+ T-cells, nor of the PD-1+ fraction within the CD4 or CD8 subsets was associated with clinical outcome. In a multivariate model with known confounders and biomarkers only the M-category (HR, 3.11; p = 0.007) and the frequency of PD-1+CD56+ T-cells (HR, 2.39; p = 0.028) were identified as independent predictive factors for clinical outcome under PD-1 blockade. Thus, a lower than median frequency of peripheral blood PD-1+CD56+ T-cells prior to starting anti-PD-1 checkpoint blockade is associated with superior clinical response, longer PFS and OS of stage IV melanoma patients.

Changes in human peripheral blood mononuclear cell (HPBMC) populations and T-cell subsets associated with arsenic and polycyclic aromatic hydrocarbon exposures in a Bangladesh cohort.

Exposures to environmental arsenic (As) and polycyclic aromatic hydrocarbons (PAH) have been shown to independently cause dysregulation of immune function. Little data exists on the associations between combined exposures to As and PAH with immunotoxicity in humans. In this work we examined associations between As and PAH exposures with lymphoid cell populations in human peripheral blood mononuclear cells (PBMC), as well as alterations in differentiation and activation of B and T cells. Two hundred men, participating in the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh, were selected for the present study based on their exposure to As from drinking water and their cigarette smoking status. Blood and urine samples were collected from study participants. We utilized multiparameter flow cytometry in PBMC to identify immune cells (B, T, monocytes, NK) as well as the T-helper (Th) cell subsets (Th1, Th2, Th17, and Tregs) following ex vivo activation. We did not find evidence of interactions between As and PAH exposures. However, individual exposures (As or PAH) were associated with changes to immune cell populations, including Th cell subsets. Arsenic exposure was associated with an increase in the percentage of Th cells, and dose dependent changes in monocytes, NKT cells and a monocyte subset. Within the Th cell subset we found that Arsenic exposure was also associated with a significant increase in the percentage of circulating proinflammatory Th17 cells. PAH exposure was associated with changes in T cells, monocytes and T memory (Tmem) cells and with changes in Th, Th1, Th2 and Th17 subsets all of which were non-monotonic (dose dependent). Alterations of immune cell populations caused by environmental exposures to As and PAH may result in adverse health outcomes, such as changes in systemic inflammation, immune suppression, or autoimmunity.

CD73 Rather Than CD39 Is Mainly Involved in Controlling Purinergic Signaling in Calcified Aortic Valve Disease.

The study aimed to compare composition of peripheral blood T-cell subsets and assess their surface expression of CD39 and CD73 ectonucleotidases in patients with severe and moderate aortic stenosis (AS) as well as to evaluate involvement of T-cell-mediated immune processes in valve calcification. The study was performed with 38 patients suffering from severe calcified aortic stenosis (SAS), 33 patients with MAS, and 30 apparently healthy volunteers (HVs). The relative distribution and percentage of T-cell subsets expressing CD39 and CD73 were evaluated by flow cytometry. T helper (Th) and cytotoxic T-cell subsets (Tcyt) were identified by using CD3, CD4, and CD8 antibodies. Regulatory T cells (Tregs) were characterized by the expression of CD3, CD4, and high IL-2R alpha chain (CD25high) levels. CD45R0 and CD62L were used to assess differentiation stage of Th, Tcyt, and Treg subsets. It was found that MAS and SAS patients differed in terms of relative distribution of Tcyt and absolute number of Treg. Moreover, the absolute number of Tcyt and terminally differentiated CD45RA-positive effector T-cells (TEMRA) subset was significantly higher in SAS vs. MAS patients and HVs. However, the absolute and relative number of naïve Th and the absolute number of Treg were significantly higher in MAS vs. SAS patients; the relative number of naïve Tregs was significantly (p < 0.01) decreased in SAS patients. It was shown that CD73 expression was significantly higher in SAS vs. MAS patients noted in all EM, CM, TEMRA, and naïve Th cell subsets. However, only the latter were significantly increased (p = 0.003) in patients compared with HVs. SAS vs. MAS patients were noted to have significantly higher percentage of CD73+ EM Tcyt (p = 0.006) and CD73+ CM Tcyt (p = 0.002). The expression of CD73 in patients significantly differed in all three Treg populations such as EM (p = 0.049), CM (p = 0.044), and naïve (p < 0.001). No significant differences in CD39 expression level was found in MAS and SAS patients compared with the HV group. Overall, the data obtained demonstrated that purinergic signaling was involved in the pathogenesis of aortic stenosis and calcification potentially acting via various cell types, wherein among enzymes, degrading extracellular ATP CD73 rather than CD39 played a prominent role.

SAT-328 DIETARY NA+ LOADING WITH NACL OR NAHCO3 PRODUCES SIMILAR CHANGES IN CIRCULATING TH17 AND REGULATORY T-CELLS

Evidence from both human and animal studies indicate that blood pressure responses to sodium (Na+) administration are dependent on the anion present with sodium, and that sodium bicarbonate (NaHCO3) promotes hypertension to a lesser degree than sodium chloride (NaCl). Recent advances implicate the immune system in the development of salt-sensitive hypertension. Specifically, Na+ loading has been reported to activate pro-inflammatory Th17 T-lymphocytes (T-cells) over anti-inflammatory regulatory T-cells (Tregs). It remains unclear however, if initiation of a diet with increased NaCl promotes a greater pro-hypertensive inflammatory response compared to NaHCO3 loading. We hypothesized that initiation of NaCl loading in rats promotes a greater pro-inflammatory T-cell response when compared to NaHCO3. Studies were performed in male Sprague Dawley rats (8-12 wks). Rats were Na+ loaded by exchanging the drinking water with either NaCl (0.1M; n = 10) or equimolar NaHCO3 (n = 17) for 3 days prior to analysis. Blood draws were performed via tail vein at baseline prior to Na+ loading, and following 3 days of either NaCl or NaHCO3 treatment. The percentage of Tregs (CD3+ CD4+ FoxP3+) and Th17 T-cells (CD3+ CD4+ RORy+) in peripheral blood was then measured via flow cytometry. Three days of treatment with NaCl significantly increased peripheral Th17 T-cells (from 1.01 ± 0.43 to 2.72 ± 0.44 [% RORy+ of % CD3+ CD4+ T-cells], p < 0.002). Treatment for three days with NaHCO3 resulted in similar increases in peripheral Th17 T-cells (from 1.15 ± 0.38 to 3.17 ± 0.47, p< 0.0002). Peripheral Treg populations were significantly increased following treatment with both NaCl (from 4.19 ± 0.53 to 8.27 ± 0.85 [% FoxP3+ of % CD3+ CD4+ T-cells], p < 0.009) and NaHCO3 (from 6.45 ± 0.42 to 10.2 ± 0.57, p < 0.0001). While both NaHCO3and NaCl resulted in significant increases in peripheral Tregs, NaHCO3 did not produce significantly greater increases in Tregs than NaCl (unpaired t-test, p = 0.73). Dietary Na+ loading with either NaHCO3 or NaCl produces similar increases in both pro-inflammatory Th17 T-cell and anti-inflammatory regulatory T-cell populations in the plasma. Our results indicating that the inflammatory response to NaCl and NaHCO3 is similar, suggest that immune responses to Na+ loading are independent of the anion present with Na+. As NaHCO3 has been reported to promote hypertension to a lesser degree than NaCl, our data indicate that the immune responses to Na+ loading with different anions are unlikely to contribute to any observed differences in blood pressure, at least during the initiating stages of hypertension. Further studies are required to investigate whether changes in circulating T-cell profiles are representative of organ infiltration or whether differences in the response of circulating T-cells to NaCl and NaHCO3 may be observed over longer periods.

Efficient identification of neoantigen-specific T-cell responses in advanced human ovarian cancer

BackgroundEfficient identification of neoantigen-specific T-cell responses in epithelial ovarian cancer (EOC) remains a challenge. Existing investigations of spontaneous T-cell response to tumor neoepitope in EOC have taken the approach of comprehensive screening all neoantigen candidates, with a validation rate of 0.5–2%.MethodsWhole-exome and transcriptome sequencing analysis of treatment-naive EOC patients were performed to identify neoantigen candidates, and the immunogenicity of prioritized neoantigens was evaluated by analyzing spontaneous neoantigen-specfic CD4+ and CD8+ T-cell responses in the tumor and/or peripheral blood. The biological relevance of neoantigen-specific T-cell lines and clones were analyzed by evaluating the capacity of autologous ovarian tumor recognition. Genetic transfer of T-cell receptor (TCR) from these neoantigen-specific T-cell clones into peripheral blood T-cells was conducted to generate neoepitope-specific T-cells. The molecular signature associated with positive neoantigen T-cell responses was investigated, and the impacts of expression level and lymphocyte source on neoantigen identification were explored.ResultsUsing a small subset of prioritized neoantigen candidates, we were able to detect spontaneous CD4+ and/or CD8+ T-cell responses against neoepitopes from autologous lymphocytes in half of treatment-naïve EOC patients, with a significantly improved validation rate of 19%. Tumors from patients exhibiting neoantigen-specific T-cell responses exhibited a signature of upregulated antigen processing and presentation machinery, which was also associated with favorable patient survival in the TCGA ovarian cohort. T-cells specific against two mutated cancer-associated genes, NUP214 and JAK1, recognized autologous tumors. Gene-engineering with TCR from these neoantigen-specific T-cell clones conferred neoantigen-reactivity to peripheral T-cells.ConclusionsOur study demonstrated the feasibility of efficiently identifying both CD4+ and CD8+ neoantigen-specific T-cells in EOC. Autologous lymphocytes genetically engineered with tumor antigen-specific TCR can be used to generate cells for use in the personalized adoptive T-cell transfer immunotherapy.

Alteration of liver-infiltrated and peripheral blood double-negative T-cells in primary biliary cholangitis.

Double-negative (DN) T-cell is a unique regulatory T-cell, which is essential for maintaining immune system homoeostasis. However, the role of DN T-cells in the pathogenesis of primary biliary cholangitis (PBC) is still unknown. We investigated the number and function of DN T-cells in peripheral blood and liver biopsy specimens of PBC patients. The number and frequency of DN T-cells significantly decreased in peripheral blood and liver tissue of PBC patients. Furthermore, the frequency of DN T-cells in PBC was negatively correlated with disease severity and positively correlated with ursodeoxycholic acid response. In vitro assays showed that perforin expression and the suppressive capability of DN T-cells on the proliferation of CD4+ and CD8+ T-cells were impaired in PBC. Finally, lithocholic acid, the most hydrophobic acid, could downregulate the proliferation and perforin expression of DN T-cells. Decreased quantity and function of DN T-cells in PBC may result in the loss of immune regulations on effector CD4+ and cytotoxic CD8+ T-cells, and thereby may break the immune tolerance and promote the pathogenesis of PBC.

Proportion of Cytotoxic Peripheral Blood Natural Killer Cells and T-Cell Large Granular Lymphocytes in Recurrent Miscarriage and Repeated Implantation Failure: Case-Control Study and Meta-analysis.

We aimed to compare the proportion of peripheral blood natural killer (NK) cells (CD3-CD56+) and T-cell large granular lymphocytes (CD8+CD57+) during preconception in a homogenous group of women with unexplained well-defined recurrent miscarriage (RM) and repeated implantation failure (RIF) vs healthy controls in relation to pregnancy outcomes. This case-control study followed by a literature review and meta-analysis was conducted in three university hospitals. Patients and controls were consecutively recruited from December 2015 to October 2017. In total, 115 women were included in the study: 54 with RM, 41 with RIF and 20 healthy controls with ≥ 2 term births. Percentages of CD3-CD56+ and CD8+CD57+ cells and sub-populations of CD3-CD56+ cells did not differ between cases and controls. The results for women with subsequent miscarriage did not differ from those with live births. The meta-analysis of the literature showed higher NK-cell proportions in RM [mean difference 3.47 (95% CI 2.94-4.00); p < 0.001] and RIF [mean difference 1.64 (95% CI 0.82-2.45); p < 0.001] than controls. However, the heterogeneity between the different studies was high. The proportion of peripheral blood CD3-CD56+ and CD8+CD57+ cells in the preconception period does not reflect the risk of implantation failure or miscarriage and should not be recommended indicators for the management of RM and RIF. Further prospective large studies are needed to develop a reliable peripheral blood marker of immune deregulation.

Neoadjuvant nivolumab in resectable non-small cell lung cancer: Extended follow-up and molecular markers of response.

8524 Background: Improved therapy is needed for patients (pts) with early-stage non-small cell lung cancer (NSCLC), as the majority relapse after curative resection. Our group reported the first trial of neoadjuvant PD-1 blockade in resectable NSCLC, finding therapy to be safe and feasible. Here we report extended clinical follow-up and long-term molecular response data from this trial. Methods: IV nivolumab 3 mg/kg was given every 2 weeks for 2 doses prior to surgery in 20 pts with resectable NSCLC at Johns Hopkins and MSKCC. Blood for correlative studies was taken prior to each dose of nivolumab, prior to surgery, 2-4 weeks post-surgery, and during long-term follow up. In a subgroup of pts, longitudinal molecular data was assessed in peripheral blood for circulating tumor DNA (ctDNA) and dynamics of tumor-infiltrating T-cell clonotypes. Results: At median follow up of 30 months (m), 15 of 20 pts are disease-free and alive. Two pts have died (one from relapsed disease). Median recurrence free survival (RFS) has not been reached. The 24m RFS rate is 69% (95% CI: 51-93). Thus far, presence of ctDNA at diagnosis and major pathologic response (MPR - ≤10% viable tumor in resected specimen) do not associate with RFS. One long-term immune-related adverse event has occurred (skin, G3). All pts who on pathologic review had ≥30% reduction in viable tumor in response to nivolumab demonstrated clearance of detectable ctDNA from blood prior to surgery. Pts with MPR experienced expansion of neoantigen-specific T-cells in peripheral blood. In one patient with ongoing disease free status, expansion of tumor-associated T-cells has persisted in peripheral blood beyond 15m from surgery. By contrast, in a patient who had detectable peri-operative ctDNA and 75% residual disease at surgery, minimal T-cell expansion was observed in peripheral blood, with a decreasing frequency of expanded T-cell clones over time that correlated with eventual cancer relapse. Conclusions: Long-term follow up reinforces the safety of neoadjuvant nivolumab in resectable NSCLC. Analysis of ctDNA and peripheral T-cell expansion in responders compared with non-responders suggests potential biomarkers for response and surveillance. While RFS data is encouraging, phase 3 trials are ongoing to evaluate efficacy of PD-(L)1 blockade in early-stage NSCLC. Clinical trial information: NCT02259621.

Phase II, prospective single-arm study of adjuvant pembrolizumab in N2 positive non-small cell lung cancer (NSCLC) treated with neoadjuvant concurrent chemoradiotherapy followed by curative resection: Preliminary results.

8520 Background: The standard treatment option for stage IIIA-N2 subgroup is still under discussion with controversies. We hypothesize that immune checkpoint inhibitor consolidation therapy could have an additional role in prolongation of the disease-free survival (DFS) for stage IIIA-N2 NSCLC treated with tri-modalities therapy. Methods: This is a phase 2 study evaluating the clinical efficacy of pembrolizumab treatment after CCRT with curative resection in stage IIIA-N2 NSCLC pts. Pathologically confirmed pts were treated with five cycles of CCRT, weekly paclitaxel (50mg/m2) and cisplatin (25mg/m2) combined with radiotherapy (total of 44Gy over 22 fractions) followed by curative resection. Adjuvant Pembrolizumab (200mg fixed dose) is applied every three weeks up to 2 years or until disease recurrence. The primary objective is disease-free survival of more than 20 months. The first patient was recruited in October 2017, and the data for this abstract was locked at 20th of January, 2019. Results: Total of 40 pts were screened, and 37 pts received treatment. Median age was 64 years (range 39-74), and twenty-three pts were male (62.2%). As a curative surgery, pts received lobectomy (n=34), bi-lobectomy (n=2), or pneumonectomy (n=1). Adenocarcinoma was predominant (n=27, 73.0%). After the neoadjuvant CCRT, down-staging were observed in nine pts (24.3%). The median follow-up duration was 10.6 months (range 3.1-17.2), and pts received a median of 11 cycles (range 1-22) of adjuvant pembrolizumab. DFS is not reached. Fourteen patients discontinued treatment due to disease progression (n=9), adverse events (n=4) and withdraw consent (n=1). There was a case of grade 4 pneumonitis and a case of grade 3 autoimmune hepatitis which lead to discontinuation of the treatment. Otherwise, grade 1-2 hypothyroidism (n=6), pneumonitis (n=5), skin rash (n=3) were observed. Patients with sever immune-related adverse event showed a significantly high percentage of Ki-67 + cells among CD8 T-cells in peripheral blood. Conclusions: This study is the first study to demonstrate the feasibility of adjuvant pembrolizumab monotherapy in stage IIIA-N2 patients. Updated and detail clinical and exploratory biomarker outcome will be presented at the annual meeting. Clinical trial information: NCT03053856.

Severe immune-related adverse events in anti-PD-1-treated patients are clustered into distinct subtypes by peripheral blood T-cell profiles.

2564 Background: Although anti-programmed death-1 (PD-1) treatment has shown remarkable anti-tumor efficacy, immune-related adverse events (irAEs) develop with heterogeneous clinical manifestations. Immunological understanding of irAEs is currently limited. In the present study, we analyzed peripheral blood T cells obtained from cancer patients who received anti-PD-1 treatment to determine the immunological characteristics of severe irAEs. Methods: This study included 31 patients with refractorythymic epithelial tumor (TET) who were enrolled in a phase II trial of pembrolizumab (NCT02607631) and 60 patients with metastatic non-small cell lung cancer (NSCLC) who received pembrolizumab or nivolumab. T-cell profiling was performed by multi-color flow cytometry using peripheral blood obtained immediately before treatment and 7 days after the first dose of anti-PD-1 antibodies. Results: Severe irAEs (≥ grade 3) occurred in 7 TET patients (22.6%) and 6 NSCLC patients (10.0%). Patients with severe irAEs exhibited a significantly lower fold increase in the frequency of effector regulatory T (eTreg) cells after anti-PD-1 treatment, higher ratio of T helper-17 (Th17) and T helper-1 cells at baseline, and higher percentage of Ki-67+cells among PD-1+CD8+T cells post-treatment. In clustering analysis, patients with severe irAEs were grouped into four distinct subtypes: Th17-related, TNF-related,Treg-related, and CD8-related. Conclusions: Severe irAEs after anti-PD-1 treatment were clustered into four immunological subtypes, indicating that development of severe irAEs is not attributed to a single mechanism. Further investigations in larger cohorts are needed to validate our current findings.

Accumulation of Circulating CCR7+ Natural Killer Cells Marks Melanoma Evolution and Reveals a CCL19-Dependent Metastatic Pathway.

Immune checkpoint blockade therapy has changed prognoses for many melanoma patients. However, immune responses that correlate with clinical progression of the disease are still poorly understood. To identify immune responses correlating with melanoma clinical evolution, we analyzed serum cytokines as well as circulating NK and T-cell subpopulations from melanoma patients. The patients' immune profiles suggested that melanoma progression leads to changes in peripheral blood NK and T-cell subsets. Stage IV melanoma was characterized by an increased frequency of CCR7+CD56bright NK cells as well as high serum concentrations of the CCR7 ligand CCL19. CCR7 expression and CCL19 secretion were also observed in melanoma cell lines. The CCR7+ melanoma cell subpopulation coexpressed PD-L1 and Galectin-9 and had stemness properties. Analysis of melanoma-derived cancer stem cells (CSC) showed high CCR7 expression; these CSCs were efficiently recognized and killed by NK cells. An accumulation of CCR7+, PD-L1+, and Galectin-9+ melanoma cells in melanoma metastases was demonstrated ex vivo Altogether, our data identify biomarkers that may mark a CCR7-driven metastatic melanoma pathway.

Hypoxia and TGF-β1 induce tissue resident memory phenotype cells from human peripheral blood T-cells in vitro

Abstract Tissue resident memory cells (TRM) are a recently identified subset of memory T-cells important in frontline defense against viral diseases and recent reports suggest T-cells with this phenotype are important in anti-tumor immunity. However, relatively little is known regarding TRM differentiation and endogenous TRM are notoriously difficult to isolate, impeding their study in basic research and downstream applications. Thus a means to generate TRM in vitro would be desirable. It is known that TGF-β is critical in establishing TRM populations and attempts to identify other factors that can induce differentiation to resident phenotype have focused on cytokines. Oxygen tension is another factor that distinguishes the circulation from peripheral tissues; thus we hypothesized that hypoxia may contribute to a TGF-β1-induced TRM phenotype in human CD8+ T-cells. We demonstrate that differentiation of human peripheral blood CD8+ T-cells in hypoxia and TGF-β1 in vitro led to the development of a TRM phenotype, characterized by a significant increase in CD69+CD103+ cells expressing CD49a, CD101, and PD-1 – hallmarks of human TRM. At the transcriptional level we observed upregulation of genes associated with TRM differentiation and downregulation of genes associated with memory cell recirculation. Hypoxia and TGF-β1 appear to synergize to induce a resident phenotype as their combination produced a significantly larger population of TRM phenotype cells than the additive effects of either condition alone. Our findings identify a previously unreported cue for TRM differentiation and enable a facile means of generating human TRM phenotype cells in vitro for basic studies and translational applications such as adoptive cellular therapies.

Alterations of Specific Lymphocytic Subsets with Ageing and with Aged-Related Metabolic and Cardiovascular Diseases

Abstract Ageing of the immune system (immunosenescence (ISC)), is a complex subject characterized by a decrease in cell-mediated immunity, particularly with T-cell function. We conducted a clinical study to analyze peripheral blood (PB) for alterations in T-cell subsets among young healthy (YH) controls, elderly healthy (EH) controls, age-matched subjects with metabolic diseases (MDs; E-MDs), and cardiovascular diseases (CVDs; E-CVDs). The frequencies of expressions of CD3T, CD8T, and invariant natural killer T (NKTs; iNKT) cells were reduced in the EH, E-MD, and E-CVD cohorts; in contrast, CD4T and regulatory T (Treg) cell frequencies tended to increase with ageing, whereas they were lower in subjects with aged-related MDs and CVDs. Moreover, subsets including naïve, effector memory T (TEM) cells, effector memory T cells re-expressing CD45RA (TEMRA), as well as the CD28−CD57+phenotype in the CD4T and CD8T subpopulations consistently showed accumulation of senescent T-cell subsets in ageing, and in patients with E-MDs and E-CVDs compared to YH volunteers. Notably, serum cytokines, including Interferon (IFN)-γ, Transforming growth factor (TGF)-β, and Growth differentiation factor (GDF)-15 levels were consistently reflection of the alterations in T-cell subsets for within-group comparisons. Ageing-, E-MD-, and E-CVD-associated changes in PB T-cell subsets were paralleled by alterations in expressions of cytokines involved in lymphopoiesis, which might play important roles in ageing, and aged-related MD- and CVD-mediated dysregulation of immune functions. Furthermore, identifying these altered T-cell subsets can potentially serve as diagnostic markers for preventing ageing problems and treating aged-related MDs and CVDs.

Biological variation of peripheral blood T-lymphocytes

BackgroundFlow cytometric analysis of the lymphocyte subsets has become one of the most commonly used techniques in the routine clinical laboratory. It is frequently used in monitoring lymphocyte recovery after hematopoietic stem cell transplantation (HSCT), as well as diagnosis and treatment of acquired immunodeficiency syndrome (AIDS). Reliable biological variation (BV) data is needed for safe clinical application of these tests. In this study, similar preanalytical and analytical protocols to the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) checklist were followed and a stringent statistical approach was applied to define BV of T-lymphocytes. MethodsDuring the 10 weeks study period, weekly blood samples were obtained from 30 healthy individuals (20 females, 10 males) and analyzed with Facs Canto (BD Biosciences, San Jose, CA, USA) analyzer using 4-colour BD Multitest CD3/CD8/CD45/CD4 reagents. Data were assessed in terms of normality, tendencies, outliers and variance homogeneity prior to applying coefficient of variance (CV)- analysis of variance (ANOVA) test. Sex-stratified within-individual (CVI) and between-individual (CVG) BV estimates of CD3+, CD3 + CD4+, CD3 + CD8+, and CD3 + CD4 + CD8+ T lymphocytes were calculated. ResultsNo difference was found between males and females. Except for the CD3 + CD4 + CD8+ subset, stable BV was found for CD3+, CD3 + CD4+, and CD3 + CD8+ subsets. ConclussionInstead of using the conventional reference ranges of CD3+, CD3 + CD4+ and CD3 + CD8+ counts for monitoring HIV positive or post-HSCT patients, RCV should be used. Because individualityis characteristic of lymphocytes subsets RCVs should be used instead of RIs for patient monitoring.

Diagnostic Biomarkers to Diagnose Acute Allograft Rejection After Liver Transplantation: Systematic Review and Meta-Analysis of Diagnostic Accuracy Studies.

Objective: A systematic review and meta-analysis of diagnostic biomarkers for noninvasive diagnosis of acute allograft rejection following liver transplantation.Background: Noninvasive blood and urine markers have been widely explored in recent decades for diagnosing acute rejection after liver transplantation. However, none have been translated into routine clinical use so far due to uncertain diagnostic accuracy, and liver biopsy remains the gold standard.Methods: Systematic literature searches of Medline, Cochrane and Embase were conducted up to February 2019 to identify studies evaluating the use of noninvasive markers in diagnosing allograft rejection following liver transplantation. Meta-analysis was performed using a random effects model with DerSimonian–Laird weighting and the hierarchical summary receiver operating curve.Results: Of 560 identified studies, 15 studies (1,445 patients) met the inclusion criteria. The following markers were tested: acid labile nitroso-compounds (NOx), serum amyloid A protein, procalcitonin, peripheral blood eosinophil count, peripheral blood T-cell activation and interleukin 2 (IL-2) receptor, guanylate-binding protein-2 mRNA, graft-derived cell-free DNA, pi-glutathione S-transferase, alpha-glutathione S-transferase and serum HLA class I soluble antigens. Only eosinophil count was tested in multiple studies, and they demonstrated high heterogeneity (I2 = 72% [95% CI: 0.5–0.99]). IL-2 receptor demonstrated the highest sensitivity (89% [95% CI: 0.78–0.96]) and specificity (81% [95% CI: 0.69–0.89]).Conclusion: IL-2 receptor expression demonstrated the highest diagnostic accuracy, while the peripheral eosinophil count was the only marker tested in more than one study. Presently, liver biopsy remains superior to noninvasive diagnostic biomarkers as most studies exhibited inferior designs, hindering possible translation into clinical application.

CD4+CD25highCD127low/-FoxP3 + Regulatory T-Cell Population in Acute Leukemias: A Review of the Literature.

Regulatory T-cells (Tregs) are a very important subtype of lymphocytes when it comes to self-control in the human immunological system. Tregs are decisive not only in the protection against destruction of own tissues by autoimmune immunocompetent cells but also in the immunological answer to developing cancers. On the other hand, Tregs could be responsible for the progression of acute and chronic leukemias. In our study, we review publications available in the PUMED database concerning acute leukemia, with a particular emphasis on child's leukemias. The percentage of regulatory T-lymphocytes in peripheral blood and bone marrow was elevated compared to those in healthy individuals and correlated with progressive disease. Regulatory T-cells taken from children diagnosed with leukemia showed a higher suppressive capability, which was confirmed by detecting elevated levels of secreted IL-10 and TGF-beta. The possibility of pharmacological intervention in the self-control of the immunological system is now under extensive investigation in many human cancers. Presumably, Treg cells could be a vital part of targeted therapies. Routine Treg determination could be used to assess the severity of disease and prognosis in children with acute lymphoblastic leukemia. This proposition results from the fact that in some studies, higher percentage of Treg cells in peripheral blood was demonstrated. However, observations confirming these facts are scarce; thus, extrapolating them to the population of children with hematological malignancies needs to be verified in additional studies.