Peripheral Memory Research Articles

Improved clinical outcome in a randomized phase II study of anti-PD-1 camrelizumab plus decitabine in relapsed/refractory Hodgkin lymphoma

BackgroundProgrammed death-1 (PD-1) blockade monotherapy induced durable remission in a subset of patients with relapsed/refractory classical Hodgkin lymphoma (cHL). We asked whether the anti-PD-1 agent, camrelizumab, combined with the DNA...

The role of immunogenic clinical death in the virotherapy of malignant neoplasms

The work considers the main directions, results of experimental and clinical researches of a role of immunogenic cell death in verotherapy of malignant neoplasms. Cell death under the influence of oncolytic viruses, which occurred in the scenario of immunogenic cell death with the release of dangerously associated molecular patterns, was estimated. Clinical cases were divided by us into 2 types according to the method of activating the stress agent of the endoplasmic reticulum. Precisely those that influenced directly on structures inside the cell besides the endoplasmic reticulum, launching its stress indirectly through targets such as cytoplasmic proteins, membrane proteins and channels, proteins of the DNA replication system, and those that launched endoplasmic reticulum stress acting directly on the endoplasmic reticulum and breaking its work. The influence of oncolytic viruses on cells of malignant neoplasms is estimated. In our opinion, a significant positive difference between oncolytic viruses and other inducers of immunogenic cell death is that the infected cell with oncolytic viruses secretes pathogen-associated molecular patterns, which are structural molecules and waste products. Such additional stimulation may enhance the activity of immunocytes and increase the efficiency of antigen presentation. We have observed that cells with low-affinity T-cell receptors can escape negative selection, but their activity is usually insufficient to launch a full immune response due to the immunosuppressive microenvironment in the tumor. Immunogenic cell death may oppress this immunosuppression and increase the activity of the low-affinity clone of T lymphocytes for some time, but after the attenuation of immunogenic cell death, this pool is rapidly suppressed by the peripheral tolerogenic mechanisms and immunological memory hardly develops. In our opinion, this is especially actual for chemotherapeutic treatment regimens, because they have a limited duration due to the development of side effects. A detailed analysis of our own research and literature data allow to mention that oncolytic viruses seem to be an effective solution as an inducer of immunogenic cell death - they multiply in the tumor and cause immunogenic cell death for a long time while they are able to infect other tumor cells, which сonsequently allow recommending them as a stage of combined treatment of patients with oncopathology. Keywords: oncology, cell death, immunogenic apoptosis, oncolytic viruses.

Frequency of Effector Memory Cells Expressing Integrin α4β7 Is Associated With TGF-β1 Levels in Therapy Naïve HIV Infected Women With Low CD4+ T Cell Count.

Integrin α4β7 expressing CD4+ T cells are preferred targets for HIV infection and are thought to be predictors of disease progression. Concurrent analysis of integrin α4β7 expressing innate and adaptive immune cells was carried out in antiretroviral (ART) therapy naïve HIV infected women in order to determine its contribution to HIV induced immune dysfunction. Our results demonstrate a HIV infection associated decrease in the frequency of integrin α4β7 expressing endocervical T cells along with an increase in the frequency of integrin α4β7 expressing peripheral monocytes and central memory CD4+ T cells, which are considered to be viral reservoirs. We report for the first time an increase in levels of soluble MAdCAM-1 (sMAdCAM-1) in HIV infected individuals as well as an increased frequency and count of integrin CD8+ memory T cells. Correlation analysis indicates that the frequency of effector memory CD8+ T cells expressing integrin α4β7 is associated with levels of both sMAdCAM-1 and TGF-β1. The results of this study also suggest HIV induced alterations in T cell homeostasis to be on account of disparate actions of sMAdCAM-1 and TGF-β1 on integrin α4β7 expressing T cells. The immune correlates identified in this study warrant further investigation to determine their utility in monitoring disease progression.

Efficacy of Decitabine plus Anti-PD-1 Camrelizumab in Patients with Hodgkin Lymphoma Who Progressed or Relapsed after PD-1 Blockade Monotherapy.

Programmed death-1 (PD-1) blockade monotherapy is effective in relapsed/refractory classical Hodgkin lymphoma (cHL), but a subset of patients is recalcitrant to PD-1 inhibitors and only a minority of patients achieves durable remission. Effective treatment regimens for those with relapsed/progressive cHL after single-agent anti-PD-1 are urgently needed. Anti-PD-1 combination with the DNA-demethylating agent decitabine showed positive preliminary results in our test cohort patients who were resistant to anti-PD-1. Here, we assess the efficacy of decitabine plus anti-PD-1 therapy in an expansion cohort and after longer follow-up. We present the response and progression-free survival rates from patients with relapsed/refractory cHL who relapsed/progressed after prior anti-PD-1 monotherapy, and who received decitabine (10 mg/day, days 1-5) plus the anti-PD-1 camrelizumab (200 mg, day 8), every 3 weeks in a phase II trial (ClinicalTrials.gov: NCT02961101 and NCT03250962). Overall, 51 patients (test cohort: 25, expansion cohort: 26) were treated and 50 evaluated for efficacy. The objective response rate was 52% [nine complete responses (CR); 36%] in the test cohort, and 68% (six CRs; 24%) in the expansion cohort. Median progression-free survival with decitabine plus camrelizumab was 20.0 and 21.6 months, respectively, which was significantly longer than that achieved with prior anti-PD-1 monotherapy. Durable response was observed in an estimated 78% of patients who achieved CR at 24 months. After decitabine plus camrelizumab, the ratio increase of circulating peripheral central memory T cells directly correlated with both clinical response and progression-free survival. Decitabine plus camrelizumab is associated with high response rates and long-term benefits in patients with relapsed/refractory cHL who failed PD-1 inhibitors.

Tissue-Resident Memory T Cells in the Lungs Protect against Acute Respiratory Syncytial Virus Infection.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection in young children. The T cell response plays a critical role in facilitating clearance of an acute RSV infection, and memory T cell responses are vital for protection against secondary RSV exposures. Tissue-resident memory (TRM) T cells have been identified as a subset of memory T cells that reside in nonlymphoid tissues and are critical for providing long-term immunity. There is currently limited information regarding the establishment and longevity of TRM T cell responses elicited following an acute RSV infection as well as their role in protection against repeated RSV infections. In this study, we examined the magnitude, phenotype, and protective capacity of TRM CD4 and CD8 T cells in the lungs of BALB/c mice following an acute RSV infection. TRM CD4 and CD8 T cells were established within the lungs and waned by 149 d following RSV infection. To determine the protective capacity of TRMs, FTY720 administration was used to prevent trafficking of peripheral memory T cells into the lungs prior to challenge of RSV-immune mice, with a recombinant influenza virus expressing either an RSV-derived CD4 or CD8 T cell epitope. We observed enhanced viral clearance in RSV-immune mice, suggesting that TRM CD8 T cells can contribute to protection against a secondary RSV infection. Given the protective capacity of TRMs, future RSV vaccine candidates should focus on the generation of these cell populations within the lung to induce effective immunity against RSV infection.

Switched and unswitched memory B cells detected during SARS-CoV-2 convalescence correlate with limited symptom duration

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the pandemic human respiratory illness COVID-19, is a global health emergency. While severe acute disease has been linked to an expansion of antibody-secreting plasmablasts, we sought to identify B cell responses that correlated with positive clinical outcomes in convalescent patients. We characterized the peripheral blood B cell immunophenotype and plasma antibody responses in 40 recovered non-hospitalized COVID-19 subjects that were enrolled as donors in a convalescent plasma treatment study. We observed a significant negative correlation between the frequency of peripheral blood memory B cells and the duration of symptoms for convalescent subjects. Memory B cell subsets in convalescent subjects were composed of classical CD24+ class-switched memory B cells, but also activated CD24-negative and natural unswitched CD27+ IgD+ IgM+ subsets. Memory B cell frequency was significantly correlated with both IgG1 and IgM responses to the SARS-CoV-2 spike protein receptor binding domain (RBD) in most seropositive subjects. IgM+ memory, but not switched memory, directly correlated with virus-specific antibody responses, and remained stable over 3 months. Our findings suggest that the frequency of memory B cells is a critical indicator of disease resolution, and that IgM+ memory B cells may play an important role in SARS-CoV-2 immunity.

Eomes Impedes Durable Response to Tumor Immunotherapy by Inhibiting Stemness, Tissue Residency, and Promoting the Dysfunctional State of Intratumoral CD8+ T Cells.

Sustaining efficacious T cell-mediated antitumor immune responses in the tumor tissues is the key to the success of cancer immunotherapy. Current strategies leverage altering the signals T cells sense in the tumor microenvironment (TME). Checkpoint inhibitor-based approaches block inhibitory signals such as PD-1 whereas cytokine-based therapies increase the level of immune-stimulatory cytokines such as IL-2. Besides extrinsic signals, the genetic circuit within T cells also participates in determining the nature and trajectory of antitumor immune responses. Here, we showed that efficacy of the IL33-based tumor immunotherapy was greatly enhanced in mice with T cell-specific Eomes deficiency. Mechanistically, we demonstrated that Eomes deficient mice had diminished proportions of exhausted/dysfunctional CD8+ T cells but increased percentages of tissue resident and stem-like CD8+ T cells in the TME. In addition, the IFNγ+TCF1+ CD8+ T cell subset was markedly increased in the Eomes deficient mice. We further demonstrated that Eomes bound directly to the transcription regulatory regions of exhaustion and tissue residency genes. In contrast to its role in inhibiting T cell immune responses at the tumor site, Eomes promoted generation of central memory T cells in the peripheral lymphoid system and memory recall responses against tumor growth at a distal tissue site. Finally, we showed that Eomes deficiency in T cells also resulted in increased efficacy of PD-1-blockade tumor immunotherapy. In all, our study indicates that Eomes plays a critical role in restricting prolonged T cell-mediated antitumor immune responses in the TME whereas promoting adaptive immunity in peripheral lymphoid organs.

Tracking Peripheral Memory T Cell Subsets in Advanced Non-Small Cell Lung Cancer Treated with Hypofractionated Radiotherapy and PD-1 Blockade in the ABSCOPAL-1 Clinical Trial

Background: Hypofractionated radiotherapy (HFRT) or chemotherapy combined with programmed death-1 (PD-1) blockade has achieved good clinical control in advanced non-small cell lung cancer (NSCLC). However, the effects of the distinct cell-killing mechanisms induced by radiotherapy and chemotherapy on immune memory remain unclear. We compared T memory subset differentiation in responders and non-responders treated with HFRT combined with PD-1 blockade to those in responders treated with chemo-immunotherapy. Methods: Thirty-eight patients with advanced NSCLC were enrolled in the trial. The frequencies of naive (Tn; CD45RA+CCR7+ ), central memory (Tcm; CD45RA–CCR7+), effector memory (Tem; CD45RA–CCR7–), and effector memory RA (TemRA; CD45RA+ CCR7–) T cell subsets and PD-1 expression were analyzed in CD4+ and CD8+ T cells using flow cytometry on single-cell suspensions from peripheral blood samples. Subsets were compared between healthy control and untreated NSCLC groups; among partial response, stable disease, and progressive disease groups treated using HFRT+PD-1 blockade; and between those treated with chemo-immunotherapy pre- and post-treatment. The correlations of memory T cell subsets and PD-1 expression with overall survival were examined using logistic regression. Findings: NSCLC patients showed expansion of the Tcm and Tem cell subsets among both CD4+ and CD8+ T cells compared with healthy controls. Patients with partial response to HFRT+PD-1 blockade showed reduction in Tn and expansion in TemRA cell subpopulations among CD8+ T cells and reduced PD-1+ CD4+ and PD-1+ CD8+ T cell counts, all of which were significantly correlated with overall survival. The responders to chemo-immunotherapy showed expansion of the TemRA CD4+ T cell subpopulation, decrease in Tcm CD4+ T and CD8+ T cell subpopulation. Conclusion: HFRT+PD-1 blockade and chemo-immunotherapy combination therapies induce differential memory T cell subset differentiation, offering predictive markers for treatment response. Trial Registration: ChiCTR-1900027768 Funding: This research was entirely funded by Functional study of Mir-183 in initiating cells of CD133+/CD326+ lung adenocarcinoma, 2013/01-2015/12, Project leader, Youth Fund project of National Natural Science Foundation of China； Immune mechanism of 3D guided Hypofractionation Radiotherapy in the treatment of lung adenocarcinoma， 2017/01-2019/12， Project leader， Luzhou People's Government - Southwest Medical University science and technology strategic cooperation fund；Luzhou Municipal Government and Southwest Medical University (2019LZXNYDC04);the joint project of People’s Government of Luxian County and Southwest Medical University (2019LXXNYKD-06);Joint Project of Sichuan University and Luzhou Industrial Research Institute (2020CDLZ-24). Declaration of Interest: None to declare. Ethical Approval: This prospective trial was approved by our ethics committee (No. KY2019276)

Peripheral effector memory regulatory T cells are incremented and functionally enhanced in successful mite monomeric allergoid sublingual immunotherapy

Peripheral effector memory regulatory T cells are incremented and functionally enhanced in successful mite monomeric allergoid sublingual immunotherapy

Comprehensive assessment of clinical and immune disorders in patients with acute concussion

Introduction. Craniocerebral trauma remains one of the most common forms of brain pathology. Its relevance is determined by both, high prevalence and significant financial costs associated with the treatment, and rehabilitation of injured. Mild forms predominate in the general structure of injury. Immune response is one of the manifestations characteristic for a complex of biochemical and pathophysiological reactions triggered in the brain in response to injury. At the same time, the subtle mechanisms of its functioning and their role in pathogenesis of diseases remain the subject of discussion. Our research was aimed to study the role of immune reactions in the pathogenesis of mild brain injury. Materials and methods. 22 patients with concussion (aged from 20 to 45) were examined. The control group included 37 healthy individuals aged 20 to 46. The examination included the collection of complaints, medical history, assessment of somatic and neurological status, neuropsychological testing. The object of laboratory research was venous blood. Attention was mainly paid to the T-helpers of central (CM, CD45RA–CD62L+) and effector (EM, CD45RA–CD62L–) memory, which were evaluated using multicolored cytometric analysis. Results. Patients presented complaints of general and cognitive nature upon admission to the hospital. Cerebellar lesion symptoms dominated while neurological status evaluation. Neuropsychological examination allowed us to detect neuro-dynamic and regulatory disorders predominance. While conducting the analysis of the main stages of cell maturation in the blood of patients with concussion, it was noted that there was a significant increase in both, relative and absolute content of central memory T-helpers compared to the control group. At the same time, the percentage of EM Th in those with injury was slightly reduced. Also, in patients with injured Th cells of central memory, the relative content of Th1 cells decreased and the relative content of Th17 cells increased. In addition, within the CM Th pool, there was an increase in the proportion of three types of Th17 — CCR6+DN Th17, Th17.1 and «classic» CCR4+CXCR3– Th17. Conclusion. Changes in T-helpers of central memory and T-helpers of peripheral memory subpopulation among CD3+CD4+ cells can be considered as a predictor of the course of concussion in the acute period. However, T cells involved in autoimmunity, do not necessarily reflect the immune system disorders. It is possible that the basis for the decrease in the Th1 level in the circulatory bed in patients with brain injury is the recruitment of immune cells. An increase in the proportion of Th17 was also detected among T-helpers of central memory patrolling the lymphoid tissue the other day after the brain injury. This circumstance may indicate the fact that in the early stages after the nervous tissue damage, processes leading to the formation of «pro-inflammatory» cells are triggered. It allows us to consider these lymphocytes as one of the main populations of immunocompetent cells possessing a neuro-destructive effect.

Peripheral memory T-cell profile is modified in patients undergoing periodontal management.

T-cells are known to have a role in periodontitis, however, the effect of periodontal therapy on peripheral memory T-cells is unclear. This study evaluated variation in peripheral memory T-cells and red complex bacteria in sub-gingival plaque in patients undergoing periodontal management. Peripheral blood mononuclear cells and sub-gingival plaque were collected from 54 periodontitis patients at baseline, 3-, 6- and 12-months post-therapy and 40 healthy controls. Periodontitis patients were divided into treatment outcome (TxO) groups based on prevalence of sites with probing depth ≥5mm as good (<10% of sites), moderate (10-20%) or poor (>20%) at study conclusion. Naïve (TN -CCR7+ CD45RA+ ), central memory (TCM -CCR7+ CD45RA- ), effector memory (TEM -CCR7- CD45RA- ) and effector memory T-cells re-expressing CD45RA (TEMRA -CCR7- CD45RA+ ) were phenotyped using flow cytometry in CD4+ , CD8+ , CD4+ CD8+ and CD4- CD8- T-cells and red complex bacteria were quantified using qPCR. At baseline, periodontitis subjects had significantly greater mean probing depths and Porphyromonas gingivalis proportions, lower TN but higher CD4+ TCM , CD8+ TCM , CD4+ CD8+ TEM and CD4- CD8- TEM cell proportions compared to health. Periodontal therapy decreased mean probing depths, P.gingivalis proportions, TEM and CD4+ and CD8+ TCM cells, but increased TN and CD4+ and CD8+ TEMRA cells. The T-cell profile in the good TxO group showed therapy-related changes in CD4+ TEM , and CD8+ TN and TEM cells, whereas, no changes were observed in the poor TxO group. Management and the reduction in red complex bacteria were associated with changes in peripheral memory T-cells in periodontitis.

Aberrant recruitment of leukocytes defines poor wound healing in patients with recessive dystrophic epidermolysis bullosa

BackgroundPoorly healing wounds are one of the major complications in patients suffering from recessive dystrophic epidermolysis bullosa (RDEB). At present, there are no effective means to analyze changes in cellular and molecular networks occurring during RDEB wound progression to predict wound outcome and design betted wound management approaches. ObjectivesTo better define mechanisms influencing RDEB wound progression by evaluating changes in molecular and cellular networks. MethodsWe developed a non-invasive approach for sampling and analysis of wound-associated constituents using wound-covering bandages. Cellular and molecular components from seventy-six samples collected from early, established and chronic RDEB wounds were evaluated by FACS-based immuno-phenotyping and ELISA. ResultsOur cross-sectional analysis determined that progression of RDEB wounds to chronic state is associated with the accumulation (up to 90 %) of CD16+CD66b+ mature neutrophils, loss of CD11b+CD68+ macrophages, and a significant increase (up to 50 %) in a number of CD11c+CD80+CD86+ activated professional antigen presenting cells (APC). It was also marked by changes in activated T cells populations including a reduction of CD45RO+ peripheral memory T cells from 80 % to 30 % and an increase (up to 70 %) in CD45RA+ effector T cells. Significantly higher levels of MMP9, VEGF-A and cathepsin G were also associated with advancing of wounds to poorly healing state. ConclusionsOur data demonstrated that wound-covering bandages are useful for a non-invasive sampling and analysis of wound-associated constituents and that transition to poorly healing wounds in RDEB patients as associated with distinct changes in leukocytic infiltrates, matrix-remodeling enzymes and pro-angiogenic factors at wound sites.

Therapeutic Cytokine Inhibition Modulates Activation and Homing Receptors of Peripheral Memory B Cell Subsets in Rheumatoid Arthritis Patients.

Memory B cells have known to play an important role in the pathogenesis of rheumatoid arthritis (RA). With the emergence of B cell-targeted therapies, the modulation of memory B cells appears to be a key therapeutic target. Human peripheral memory B cells can be distinguished based on the phenotypic expression of CD27 and IgD, characterizing the three major B cell subpopulations: CD27+IgD+ pre-switch, CD27+IgD- post-switch, and CD27-IgD- double-negative memory B cells. We evaluated different memory cell populations for activation markers (CD95 and Ki-67) and chemokine receptors (CXCR3 and 4) expressing B cells in active RA, as well as under IL6-R blockade by tocilizumab (TCZ) and TNF-α blockade by adalimumab (ADA). Memory B cells were phenotypically analyzed from RA patients at baseline, week 12, and week 24 under TCZ or ADA treatment, respectively. Using flow cytometry, surface expression of CD95, intracellular Ki-67, and surface expressions of CXCR3 and CXCR4 were determined. Compared with healthy donors (n = 40), the phenotypic analysis of RA patients (n = 80) demonstrated that all three types of memory B cells were activated in RA patients. Surface and intracellular staining of B cells showed a significantly higher percentage of CD95+ (p < 0.0001) and Ki-67+ (p < 0.0001) cells, with numerically altered CXCR3+ and CXCR4+ cells in RA. CD95 and Ki-67 expressions were highest in post-switch memory B cells, whereas CD19+CXCR3+ and CD19+CXCR4+ expressing cells were substantially higher in the pre-switch compartment. In all subsets of the memory B cells, in vivo IL-6R, and TNF-α blockade significantly reduced the enhanced expressions of CD95 and Ki-67. Based on our findings, we conclude that the three major peripheral memory B cell populations, pre-, post-switch, and double-negative B cells, are activated in RA, demonstrating enhanced CD95 and Ki-67 expressions, and varied expression of CXCR3 and CXCR4 chemokine receptors when compared with healthy individuals. This activation can be efficaciously modulated under cytokine inhibition in vivo.

Inflammation and Oral Contraceptive Use in Female Athletes Before the Rio Olympic Games.

This study investigated the association between synthetic ovarian hormone use [i.e., the oral contraceptive (OC) pill] and basal C-reactive protein (CRP), peripheral blood immune cell subsets, and circulating pro- and anti-inflammatory cytokine concentrations in elite female athletes. Elite female athletes (n = 53) selected in Rio Summer Olympic squads participated in this study; 25 were taking an OC (AthletesOC) and 28 were naturally hormonally cycling (AthletesNC). Venous blood samples were collected at rest for the determination of sex hormones, cortisol, CRP, peripheral blood mononuclear memory and naïve CD4+ T-cells, CD8+ T-cells and natural killer cells, as well as pro- and anti-inflammatory cytokine concentrations. C-reactive protein concentrations were elevated (p < 0.001) in AthletesOC (median = 2.02, IQR = 3.15) compared to AthletesNC (median = 0.57, IQR = 1.07). No differences were reported for cortisol, cytokines, or PBMC immune cell subsets, although there was a trend (p = 0.062) for higher IL-6 concentrations in AthletesNC. Female Olympians had substantially higher CRP concentrations, a marker of inflammation and tissue damage, before the Rio Olympic Games if they used an OC. Future research should examine the potential consequences for athlete performance/recovery so that, if necessary, practitioners can implement prevention programs.

Distinctive binding properties of human monoclonal LGI1 autoantibodies determine pathogenic mechanisms.

Autoantibodies against leucine-rich glioma inactivated 1 (LGI1) are found in patients with limbic encephalitis and focal seizures. Here, we generate patient-derived monoclonal antibodies (mAbs) against LGI1. We explore their sequences and binding characteristics, plus their pathogenic potential using transfected HEK293T cells, rodent neuronal preparations, and behavioural and electrophysiological assessments in vivo after mAb injections into the rodent hippocampus. In live cell-based assays, LGI1 epitope recognition was examined with patient sera (n = 31), CSFs (n = 11), longitudinal serum samples (n = 15), and using mAbs (n = 14) generated from peripheral B cells of two patients. All sera and 9/11 CSFs bound both the leucine-rich repeat (LRR) and the epitempin repeat (EPTP) domains of LGI1, with stable ratios of LRR:EPTP antibody levels over time. By contrast, the mAbs derived from both patients recognized either the LRR or EPTP domain. mAbs against both domain specificities showed varied binding strengths, and marked genetic heterogeneity, with high mutation frequencies. LRR-specific mAbs recognized LGI1 docked to its interaction partners, ADAM22 and ADAM23, bound to rodent brain sections, and induced internalization of the LGI1-ADAM22/23 complex in both HEK293T cells and live hippocampal neurons. By contrast, few EPTP-specific mAbs bound to rodent brain sections or ADAM22/23-docked LGI1, but all inhibited the docking of LGI1 to ADAM22/23. After intrahippocampal injection, and by contrast to the LRR-directed mAbs, the EPTP-directed mAbs showed far less avid binding to brain tissue and were consistently detected in the serum. Post-injection, both domain-specific mAbs abrogated long-term potentiation induction, and LRR-directed antibodies with higher binding strengths induced memory impairment. Taken together, two largely dichotomous populations of LGI1 mAbs with distinct domain binding characteristics exist in the affinity matured peripheral autoantigen-specific memory pools of individuals, both of which have pathogenic potential. In human autoantibody-mediated diseases, the detailed characterization of patient mAbs provides a valuable method to dissect the molecular mechanisms within polyclonal populations.

Predictive value of circulating B cells and T cell subsets in melanoma patients treated with neoadjuvant ipilimumab and interferon.

e15036 Background: Patients with locally/regionally advanced melanoma were treated on a clinical trial with a neoadjuvant combination of ipilimumab (ipi) and high dose IFNα2b (HDI) (Tarhini et al, JITC 2018). In this study, immune cell composition in peripheral blood samples collected at various time points was measured to determine any correlation with clinical outcomes and investigate the immune modulating effect of the combination therapy. Methods: Patients were randomized to neoadjuvant ipi at 3 mg/kg or 10 mg/kg, both given in combination with HDI. Tumor radiologic responses were designated as complete (CR), partial (PR), stable disease (SD) or disease progression (PD). Pathologic complete response (pCR) was defined as absence of viable tumor on histologic assessment. Peripheral blood mononuclear cells (PBMC) from treated patients (N = 28) were tested at baseline (before initiating ipi-HDI), then at 6-weeks, 3-months and 12-months (following neoadjuvant ipi-HDI). High complexity (14-color) flow cytometry analysis was performed to detect key immunological biomarkers including myeloid derived suppressor cells (MDSCs), B cells, regulatory T cells (Tregs), PD-1 and TIM3 expression on T-cells, and differentiation of T-cells into Th1, Th2 or Th17 phenotype at different time points during systemic immunotherapy. Statistical significance was determined using R-package employing Kruskal’s test. Results: Lower levels of peripheral Tregs (p = 0.02), MDSCs (p = 0.05), and CD4 effector memory cells (p = 0.04) at 3-months post treatment correlated with radiologic response. In addition, lower change from baseline at 3 months in CD4/CD8 ratio (p = 0.04), levels of Tregs (p = 0.01) and CD4 effector memory cells (p = 0.02) was associated with radiologic response. Patients exhibiting pCR had significantly lower Tregs (p = 0.04) at 6-months post treatment and significantly higher CD8 central memory cells at both 3 months (p = 0.04) and 12 month time-points (p = 0.01) as compared to patients without pCR. Finally, patients without pCR had significantly lower change from baseline in CD19 B cells at 6 months (p = 0.01) and 12 months (p = 0.04) as compared to patients with pCR. Conclusions: Our data demonstrates that the levels of immunosuppressive cells including Tregs and MDSCs in periphery are negatively associated with response. Higher levels of CD8 memory cells and B cells on-treatment are associated with clinical benefit.

Evidence for HIV-1 cure after CCR5Δ32/Δ32 allogeneic haemopoietic stem-cell transplantation 30 months post analytical treatment interruption: a case report

SummaryBackgroundThe London patient (participant 36 in the IciStem cohort) underwent allogeneic stem-cell transplantation with cells that did not express CCR5 (CCR5Δ32/Δ32); remission was reported at 18 months after analytical treatment interruption (ATI). Here, we present longer term data for this patient (up to 30 months after ATI), including sampling from diverse HIV-1 reservoir sites.MethodsWe used ultrasensitive viral load assays of plasma, semen, and cerebrospinal fluid (CSF) samples to detect HIV-1 RNA. In gut biopsy samples and lymph-node tissue, cell-copy number and total HIV-1 DNA levels were quantified in multiple replicates, using droplet digital PCR (ddPCR) and quantitative real-time PCR. We also analysed the presence of intact proviral DNA using multiplex ddPCR targeting the packaging signal (ψ) and envelope (env). We did intracellular cytokine staining to measure HIV-1-specific T-cell responses. We used low-sensitive and low-avidity antibody assays to measure the humoral response to HIV-1. We predicted the probability of rebound using a mathematical model and inference approach.FindingsHIV-1 viral load in plasma remained undetectable in the London patient up to 30 months (last tested on March 4, 2020), using an assay with a detection limit of 1 copy per mL. The patient's CD4 count was 430 cells per μL (23·5% of total T cells) at 28 months. A very low-level positive signal for HIV-1 DNA was recorded in peripheral CD4 memory cells at 28 months. The viral load in semen was undetectable in both plasma (lower limit of detection [LLD] <12 copies per mL) and cells (LLD 10 copies per 106 cells) at 21 months. CSF was within normal parameters at 25 months, with HIV-1 RNA below the detection limit (LLD 1 copy per mL). HIV-1 DNA by ddPCR was negative in rectum, caecum, and sigmoid colon and terminal ileum tissue samples at 22 months. Lymph-node tissue from axilla was positive for the long-terminal repeat (33 copies per 106 cells) and env (26·1 copies per 106 cells), negative for ψ and integrase, and negative by the intact proviral DNA assay, at 27 months. HIV-1-specific CD4 and CD8 T-cell responses have remained absent at 27 months. Low-avidity Env antibodies have continued to decline. Mathematical modelling suggests that the probability of remission for life (cure) is 98% in the context of 80% donor chimerism in total HIV target cells and greater than 99% probability of remission for life with 90% donor chimerism.InterpretationThe London patient has been in HIV-1 remission for 30 months with no detectable replication-competent virus in blood, CSF, intestinal tissue, or lymphoid tissue. Donor chimerism has been maintained at 99% in peripheral T cells. We propose that these findings represent HIV-1 cure.FundingWellcome Trust and amfAR (American Foundation for AIDS Research).

Abstract P5-04-07: Defining T cell dysfunctionality in breast cancer by single cell analysis: Implications for immunotherapy

Abstract Background Despite the well-known association between extensive lymphocytic infiltration in breast cancer (BC), good prognosis, and high response rates to neoadjuvant chemotherapy (CT), pathologic evaluation of tumor infiltrating lymphocytes (TILs) is currently not routine and a deep understanding of the properties of TILs, remain largely unfilled. So far, only in triple-negative (TN), PD-L1 positive BCs it has been possible to demonstrate a survival benefit with immunotherapy plus CT, thereby making the definition of possible immunotherapeutic targets across all biological subtypes a fundamental requirement. Material and methods Single-cell RNA-sequencing (scRNAseq) data from 8 BCs were downloaded from Gene Expression Omnibus dataset (GSE114725), obtaining CD45+ single cells only from the tumoral compartment. scRNAseq-guided high-dimensional profiling by 27-parameter FACS was then applied to a large cohort (n=54, including luminal-like, TN and HER2+ BCs) of early BC patients surgically treated at our Institution. We simultaneously profiled the peripheral blood, the normal and tumoral tissue from each patient and acquired using FACS Symphony A5 flow cytometer (BD Biosciences). Flow Cytometry Standard (FCS) 3.0 files were imported into FlowJo software v9, and analyzed by standard gating to remove aggregates and dead cells, and subsequently imported in FlowJo v10, biexponentially transformed, and exported for further analysis in R by a custom-made script, using an ad-hoc pipeline. Data were analyzed using the Phenograph unbiased algorithm coded in the cytofkit package. Data were further analyzed in FlowJo to determine the frequency of positive cells for each marker and the corresponding median fluorescence intensity (MFI). These values were multiplied to derive the integrated MFI; hierarchical metaclustering of all samples, based on the frequency of Phenograph clusters, was performed in R based on the Euclidean distance and Ward-linkage. Pearson correlation analysis was used to investigate the relationship between CD8+ and CD4+ clusters. Results Our scRNA-guided informative 27-colors flow cytometry panel included antibodies to define not only different lymphocyte subpopulations, but also different stages of T lymphocytes: differentiation and memory maturation (CCR7, CD45RA), activation status (HLA-DR), cytotoxicity (GZMK, GZMB), exhaustion (PD-1, TIGIT) and tissue residency (CD69, CD103). Focusing on CD8+ T cells, we observed, as expected, bona fide naïve T cells to be virtually absent at the tumor site and enriched in peripheral blood, while cytotoxic and effector memory cells were enriched in the tumor compartment. Of note, we identified a population of tissue resident memory T cells (Trm) CD69+ CD103+, CD39+, specifically enriched in the tumor, that could be further subdivided into a HLA-DR+ CD127- and a HLA-DR- CD127+ subpopulation. Interestingly, the HLA-DR+ subset exhibited more exhaustion markers (PD-1hi, TIGIT+, NKG2A+) and was significantly positively correlated with CD4+ regulatory T cells. We speculated, and deeply investigated by bulk RNA-seq, that these two subsets of Trm might represent different maturation states and that they could be reinvigorated targeting highly expressed inhibitory molecules using approved (e.g., PD-1) together with newly identified (e.g., NKG2A) immunotherapeutics. Moreover, as no difference was observed in the relative distribution of Phenograph clusters, our data may be applied to revert acquired immune escape mechanisms in all different BC biological subtypes. Conclusions We identified, among Trm CD69+ CD103+, tumor-specific CD39+, PD1+ exhausted population, novel dysfunctional NKG2A+ T cells previously not characterized in BC. This population is of extreme interest to characterize a novel potential immunotherapeutic target. Citation Format: Agnese Losurdo, Caterina Scirgolea, Emilia Mazza, Valentina Errico, Bethania Fernandes, Luca Di Tommaso, Andrea Sagona, Karolina Pilipow, Rosalba Torrisi, Giovanna Masci, Rita De Sanctis, Elisa Agostinetto, Alberto Testori, Corrado Tinterri, Massimo Roncalli, Armando Santoro, Enrico Lugli. Defining T cell dysfunctionality in breast cancer by single cell analysis: Implications for immunotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-07.

Decreased peripheral blood memory B cells are associated with the presence of interstitial lung disease in rheumatoid arthritis: a case-control study

Objectives Interstitial lung disease sometimes occurs in rheumatoid arthritis patients. Although the underlying immunological mechanisms responsible for interstitial lung disease associated with rheumatoid arthritis have not yet been clarified, some reports have suggested possible roles of B cells. To examine the role of B-cell subsets in interstitial lung disease in rheumatoid arthritis patients, we analyzed peripheral blood B-cell subsets. Methods We analyzed the frequencies of the peripheral blood B-cell subsets by flow cytometry in rheumatoid arthritis patients with and without interstitial lung disease (n = 16 and 81, respectively) and in healthy donors (n = 110) by high-resolution computed tomography. Results Compared with healthy donors, rheumatoid arthritis patients showed statistically higher frequencies of naive B cells and lower frequencies of memory B cells. Moreover, the frequencies of memory B cells were lower in rheumatoid arthritis patients with interstitial lung disease than in those without. Multivariate analysis showed that the frequency of memory B cells, particularly switched memory B cells, was significantly decreased in rheumatoid arthritis patients with interstitial lung disease, even after adjusting for prednisolone dose. Conclusions We suspect memory B cells play important roles in interstitial lung disease associated with rheumatoid arthritis.

Compatible byte-addressable direct I/O for peripheral memory devices in Linux

Memory devices can be used as storage systems to provide a lower latency that can be achieved by disk and flash storage. However, traditional buffered input/output (I/O) and direct I/O are not optimized for memory-based storages. Traditional buffered I/O includes a redundant memory copy with a disk cache. Traditional direct I/O does not support byte addressing. Memory-mapped direct I/O, which optimizes file operations for byte-addressable persistent memory and appears to the CPU as a main memory. However, it has an interface that is not always compatible with existing applications. In addition, it cannot be used for peripheral memory devices (e.g., networked memory devices and hardware RAM drives) that are not interfaced with the memory bus. This paper presents a new Linux I/O layer, byte direct I/O (BDIO), that can process byte-addressable direct I/O using the standard application programming interface. It requires no modification of existing application programs and can be used not only for the memory but also for the peripheral memory devices that are not addressable by a memory management unit. The proposed BDIO layer allows file systems and device drivers to easily support BDIO. The new I/O achieved 18% to 102% performance improvements in the evaluation experiments conducted with online transaction processing, file server, and desktop virtualization storage.