Higher Proportion Of CD4 Research Articles

Development of a poor-prognostic-mutations derived immune prognostic model for acute myeloid leukemia

Leukemia cell-intrinsic somatic mutations and cytogenetic abnormalities have been used to define risk categories in acute myeloid leukemia (AML). In addition, since the immune microenvironment might influence prognosis and somatic mutations have been demonstrated to modulate the immune microenvironment in AML, there is need for developing and evaluating an immune prognostic model (IPM) derived from mutations associated with poor prognosis. Based on AML cases with intermediate and adverse-cytogenetic risk in the Cancer Genome Atlas (TCGA) database, 64 immune-related differentially expressed genes (DEGs) among patients with RUNX1, TP53, or ASXL1 mutations and patients without these mutations were identified. After Cox proportional hazards analysis, an IPM composed of PYCARD and PEAR1 genes was constructed. IPM defined high-risk (IPM-HR) independently predicted lower 2-year overall survival (OS) rates in both patients with intermediate and adverse-cytogenetic risks and non-M3 patients in the TCGA AML cohort. The poor prognostic impact of IPM-HR on OS was further validated by GSE71014, 37642, and 10358 downloaded from the Gene Expression Omnibus (GEO) database. Furthermore, IPM-HR was remarkably associated with higher proportions of CD8+ T cells and regulatory T cells (Tregs), lower proportions of eosinophils, and higher expression of the checkpoint molecules CTLA-4, PD-1, and LAG3 in the TCGA non-M3 AML cohort. In summary, we developed and validated an IPM derived from mutations related with poor prognosis in AML, which would provide new biomarkers for patient stratification and personalized immunotherapy.

A proportion of CD4+ T cells from patients with chronic Chagas disease undergo a dysfunctional process, which is partially reversed by benznidazole treatment

Signs of senescence and the late stages of differentiation associated with the more severe forms of Chagas disease have been described in the Trypanosoma cruzi antigen-specific CD4+ T-cell population. However, the mechanisms involved in these functions are not fully known. To date, little is known about the possible impact of benznidazole treatment on the T. cruzi-specific functional response of CD4+ T cells. The functional capacity of CD4+ T cells was analyzed by cytometric assays in chronic Chagas disease patients, with indeterminate form (IND) and cardiac alterations (CCC) (25 and 15, respectively) before and after benznidazole treatment. An increase in the multifunctional capacity (expression of IFN-γ, IL-2, TNF-α, perforin and/or granzyme B) of the antigen-specific CD4+ T cells was observed in indeterminate versus cardiac patients, which was associated with the reduced coexpression of inhibitory receptors (2B4, CD160, CTLA-4, PD-1 and/or TIM-3). The functional profile of these cells shows statistically significant differences between IND and CCC (p<0.001), with a higher proportion of CD4+ T cells coexpressing 2 and 3 molecules in IND (54.4% versus 23.1% and 4.1% versus 2.4%, respectively). A significant decrease in the frequencies of CD4+ T cells that coexpress 2, 3 and 4 inhibitory receptors was observed in IND after 24-48 months of treatment (p<0.05, p<0.01 and p<0.05, respectively), which was associated with an increase in antigen-specific multifunctional activity. The IND group showed, at 9-12 months after treatment, an increase in the CD4+ T cell subset coproducing three molecules, which were mainly granzyme B+, perforin+ and IFN-γ+ (1.4% versus 4.5%). A CD4+ T cell dysfunctional process was detected in chronic Chagas disease patients, being more exacerbated in those patients with cardiac symptoms. After short-term benznidazole treatment (9-12 months), indeterminate patients showed a significant increase in the frequency of multifunctional antigen-specific CD4+ T cells.

Characteristic of CD4+CD25+ T Cells in Chronic Myeloid Leukemia Patients Treated with Imatinib Mesylate with Different BCR-ABL Transcripts Levels Response

Background: Several clinical trials on cancer showed a correlation between elevated levels of regulatoryT cells with either poor prognosis or poor response to some therapies. Hence, in this study we tried tomeasure the regulatory T cells (CD4+CD245+) count and to evaluate the program death receptor 1(PD1)as a one of the main suppressive mechanisms that regulatory T cells use in CML patients with differentmolecular response to imatinib therapy. Method: Flow cytometry technique was used to analyze 30 sampleof optimal molecular response of CML patients (BCR-ABL transcripts ? 0.1%) and 30 sample of failuremolecular response patients (BCR-ABL transcripts &gt;1%) with or without hematological failure, in order toassess the CD4+CD25+ T cells (Tregs) and PD1 expression on these cells. Thirty samples age and gendermatched were used as healthy controls. Results: A high proportion of CD4+CD25+ T cells was found infailure groups compared to control and optimal groups(P= &lt;0.001), while there was no significant differencebetween control and optimal groups with (P= 0.481). A cutoff value of CD4+CD25+ T cells at &gt;33.7 % washighly significant with high sensitivity and specificity. This value can be used to determine the failure fromthe optimal CML responders. There was no noticeable differences (P= 0.125) in PD1+ expression amongCD4+CD25+ T cells. Conclusion: A high percentage of Treg cells in the failure CML group might be anindication of immune escape of leukemic cells in those patients compared to the other investigated groups.

Combining Bioinformatics Techniques to Study the Key Immune-Related Genes in Abdominal Aortic Aneurysm

Approximately 13,000 people die of an abdominal aortic aneurysm (AAA) every year. This study aimed to identify the immune response-related genes that play important roles in AAA using bioinformatics approaches. We downloaded the GSE57691 and GSE98278 datasets related to AAA from the Gene Expression Omnibus database, which included 80 AAA and 10 normal vascular samples. CIBERSORT was used to analyze the samples and detect the infiltration of 22 types of immune cells and their differences and correlations. The principal component analysis showed significant differences in the infiltration of immune cells between normal vascular and AAA samples. High proportions of CD4+ T cells, activated mast cells, resting natural killer cells, and 12 other types of immune cells were found in normal vascular tissues, whereas high proportions of macrophages, CD8+ T cells, resting mast cells, and six other types of immune cells were found in AAA tissues. In the selected samples, we identified 39 upregulated (involved in growth factor activity, hormone receptor binding, and cytokine receptor activity) and 133 downregulated genes (involved in T cell activation, cell chemotaxis, and regulation of immune response mediators). The key differentially expressed immune response-related genes were screened using the STRING database and Cytoscape software. Two downregulated genes, PI3 and MAP2K1, and three upregulated genes, SSTR1, GPER1, and CCR10, were identified by constructing a protein–protein interaction network. Functional enrichment of the differentially expressed genes was analyzed, and the expression of the five key genes in AAA samples was verified using quantitative polymerase chain reaction, which revealed that MAP2K1 was downregulated in AAA, whereas SSTR1, GEPR1, and CCR10 were upregulated; there was no significant difference in PI3 expression. Our study shows that normal vascular and AAA samples can be distinguished via the infiltration of immune cells. Five genes, PI3, MAP2K1, SSTR1, GPER1, and CCR10, may play important roles in the development, diagnosis, and treatment of AAA.

Prognostic Impact of Peripheral Blood T-Cell Subsets at the Time of Diagnosis on Survival in Patients with Diffuse Large B-Cell Lymphoma

Introduction: The effects of lymphocyte subtypes, including helper (Th), natural killer (NK), and regulatory (Treg) cells, and other T-cell subtypes on treatment outcomes in diffuse large B-cell lymphoma (DLBCL) patients are not clearly established. Methods: Among 151 consecutive patients diagnosed with DLBCL, we collected peripheral blood samples at diagnosis from 91 patients who received at least 1 cycle of R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab) chemotherapy and analyzed lymphocyte subsets by flow cytometry. Results: DLBCL patients had a higher proportion of CD4⁺CD25⁺ Treg (p < 0.001) and lower absolute lymphocyte count than those of healthy controls. Lymphopenia at diagnosis was associated with advanced-stage disease (p = 0.001), a high-intermediate/high-risk International Prognostic Index (IPI) (p < 0.001), and older age (p = 0.060). High-intermediate/high-risk IPI, high proportion of CD3⁺CD4⁺ Th cells, and extranodal site ≥2 correlated with unfavorable prognostic factors for survival. High proportion of Th cells was associated with fewer cytotoxic T cells and NK cells at the time of diagnosis. Conclusion: This study showed an association between circulating lymphocyte subsets including Th cells, Tregs, and NK cells and clinical outcomes in DLBCL; however, further confirmation is needed via prospective trials.

PD-1/PD-L1 expression profiles within intrahepatic cholangiocarcinoma predict clinical outcome

ObjectiveImmunotherapy targeting the programmed cell death protein-1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) pathway has been observed to be efficient in several solid tumors. We aim to investigate the prognostic significance of PD-1/PD-L1 expression profile in intrahepatic cholangiocarcinoma (ICC).Materials and methodsWe investigated the expression of PD-1, PD-L1, CD8+ T cells, and CD68+ macrophages in paired tumor and adjacent normal tissues from 322 ICC patients using tyramide signal amplification (TSA)-based multiplexed immunohistochemistry.ResultsWe found that high proportion of tumor-infiltrating CD8+ PD-1High within CD8+ PD-1+ T cells significantly correlated with advanced TNM stage (P = 0.035). ICC patients with high proportion of CD8+ PD-1High in CD8+ PD-1+ had worse postoperative survival than low proportion patients (P = 0.0037), which was an independently prognostic factor for OS (P = 0.025,). The density of CD68+ PD-L1+ significantly and positively correlated with the density of CD8+ PD-1High (P < 0.0001, r = 0.5927). The proportion of CD68+ PD-L1+ within CD68+ ICC was the risk factor for OS and TTR but not an independently factor for prognosis. The CD68+ PD-L1+ macrophages and CD8+ PD-1High T cells may cooperatively play a role in inhibiting anti-tumor immunity.ConclusionCD68+ PD-L1+ macrophages and CD8+ PD-1High T cells predict unfavorable prognosis, which could also bring new progress about immune target therapy in ICC research.

Idecabtagene Vicleucel (ide-cel, bb2121) Responses Are Characterized By Early and Temporally Consistent Activation and Expansion of CAR T Cells with a T Effector Phenotype

Idecabtagene Vicleucel (ide-cel, bb2121) Responses Are Characterized By Early and Temporally Consistent Activation and Expansion of CAR T Cells with a T Effector Phenotype

Diagnostic significance of flow cytometry scales in diagnostics of myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) can present a challenge for clinicians. Multicolor flow cytometry (MFC) can aid in establishing a diagnosis. The aim of this study was to determine the optimal MFC approach for MDS. The study included 102 MDS (39 low-grade MDS), 83 cytopenic patients without myeloid neoplastic disorders (control group), and 35 healthy donors. Bone marrow was analyzed using a six-color MFC. Analysis was conducted according to the "Ogata score," "Wells score," and the integrated flow cytometry (iFC) score. The respective sensitivity and specificity values were 77.5% and 90.4% for the Ogata score, 79.4% and 81.9% for the Wells score, and 87.3% and 87.6% for the iFC score. Specificity was not 100% due to deviations of MFC parameters in the control group. Patients with paroxysmal nocturnal hemoglobinuria (PNH) had higher levels of CD34+ CD7+ myeloid cells than donors. Aplastic anemia and PNH were characterized by a high proportion of CD56+ cells among CD34+ precursors and neutrophils. The proportion of MDS-related features increased with the progression of MDS. The highest number of CD34+ blasts was found in MDS with excess blasts. MDS with isolated del(5q) was characterized by a high proportion of CD34+ CD7+ cells and low granularity of neutrophils. In 39 low-grade MDS, the sensitivities were 53.8%, 61.5%, and 71.8% for Ogata score, Wells score, and iFC, respectively. The results support iFC as a useful diagnostic tool in MDS.

Impact of Age and HIV Status on Immune Activation, Senescence and Apoptosis.

IntroductionResidual immune dysfunctions, resembling those that occur during normal aging, may persist even in well-treated people with HIV (PWH), and accelerated aging has been proposed. We aimed to determine if HIV infection is an independent risk factor for T-cell immune dysfunctions including increased immune activation, senescence and apoptosis. Moreover, in PWH we aimed to identify the associations between age and immune activation, senescence and apoptosis.Materials and MethodsWe included 780 PWH with suppressed viral replication (<50 copies/mL) and absence of hepatitis B and hepatitis C co-infection and 65 uninfected controls from the Copenhagen Co-morbidity in HIV Infection (COCOMO) Study. Flow cytometry was used to determine T-cell activation (CD38+HLA-DR+), senescence (CD28-CD57+), and apoptosis (CD28-CD95+). T-cell subsets are reported as proportions of CD4+ and CD8+ T-cells. We defined an elevated proportion of a given T-cell subset as above the 75th percentile. Regression models were used to determine the association between HIV status and T-cell subset and in PWH to determine the association between age or HIV-specific risk factors and T-cell subsets. Furthermore, an interaction between HIV status and age on T-cell subsets was investigated with an interaction term in models including both PWH and controls. Models were adjusted for age, sex, BMI, and smoking status.ResultsIn adjusted models a positive HIV status was associated with elevated proportions of CD8+ activated (p = 0.009), CD4+ senescent (p = 0.004), CD4+ apoptotic (p = 0.002), and CD8+ apoptotic (p = 0.003) T-cells. In PWH a 10-year increase in age was associated with higher proportions of CD4+ and CD8+ senescent (p = 0.001 and p < 0.001) and CD4+ and CD8+ apoptotic T-cells (p < 0.001 and p < 0.001). However, no interaction between HIV status and age was found. Furthermore, in PWH a CD4+/CD8+ ratio < 1 was associated with elevated proportions of T-cell activation, senescence, and apoptosis.DiscussionWe found evidence of residual T-cell immune dysfunction in well-treated PWH without HBV or HCV co-infection, and age was associated with T-cell senescence and apoptosis. Our data supports that HIV infection has similar effects as aging on T-cell subsets. However, since no interaction between HIV status and age was found on these parameters, we found no evidence to support accelerated immunological aging in PWH.

Clinical Features and Outcomes in Imported and Non-Imported Patients with COVID-19 in Chongqing, China: A&amp;nbsp;Retrospective, Multi-Centre, Descriptive Study

Background: Global outbreak of novel coronavirus 2019 (COVID-19) continues to constitute a public health emergency of international concern. However, few studies have directly compared the differences of clinical features and outcomes between imported and non-imported COVID-19 patients. Methods: In this retrospective, multi-centre, descriptive study, we enrolled 275 patients (53 imported cases and 222 non-imported cases) with laboratory-confirmed COVID-19 from four designated hospitals in Chongqing, China. Epidemiological, demographic, clinical, laboratory, treatment, and outcome data were collected and analyzed. Outcomes were followed up until Mar 1, 2020. Findings: The proportion of asymptomatic patients in the non-imported group was significantly higher than that in the imported group (18.9% vs. 3.8%, p=0.016), and the proportions of symptoms of fever, sore throat and diarrhea in the non-imported group were all lower than those in the imported group (p≤0.048). The imported group had a lower lymphocyte count (1.1×109/L vs. 1.5×10 9 /L, p=0.018), higher neutrophil-to-lymphocyte ratio (NLR) value (2.6 vs. 2.3, p=0.0237), higher proportion of CD4+ T cells reduction (70% vs. 44.6%, p=0.043), longer duration of viral shedding (20 days vs. 18 days, p = 0.0416) than the non-imported group. As to asymptomatic patients in non-imported group, 33.3% had no abnormal chest CT images. They had higher proportion of ground-glass opacity (21.4% vs. 5.6%, p=0.004), lower proportions of bilateral patchy shadowing (7.1% vs. 21%, p=0.027) and multiple manifestations (21.4% vs. 31.3%, p=0.014), higher lymphocyte count (1.6×109/L vs. 1.3×109/L, p=0.003) including both CD4+ (567 vs. 414, p=0.029) and CD8+ (370 vs. 279, p=0.003) T cells than the symptomatic patients in non-imported group. Furthermore, when compared with imported group, asymptomatic group showed higher lymphocyte count (1.6×109/L vs. 1.1×109 /L, p+ T cells(567 vs.375, p=0.029), while the symptomatic group showed no difference in lymphocyte count, CD4+ or CD8+ T cells (p ≥ 0.0894). Interpretation: In our retrospective study, we found the non-imported group displayed higher lymphocyte count, lower proportion of CD4+ T cells reduction, lower NLR value, shorter duration of viral shedding, but more atypical symptoms and a much higher asymptomatic proportion when compared with imported cases. Our further subgroup analysis suggested that the counts of lymphocyte and CD4+ T cell from non-imported asymptomatic group were higher than those in the imported patients, but there were no difference between non-imported symptomatic and imported patients. Our results indicated that when compared with imported patients, damage to the immune system by SARS-Cov-2 in non-imported patients was milder, and this might be mainly due to its higher asymptomatic proportion. Funding: National Natural Science Foundation of China (No. 81500015). Natural Science Foundation of Chongqing Science and technology bureau (No. cstc2018jcyjAX0115). National Natural Science Foundation of Chongqing (No. cstc2019jcyj‑msxmX0849). The Joint Fund of Science and Health Medicine of Chongqing, China (No. 2019QNXM004).Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: This study is approved by Ethics Committees of the four hospitals mentioned above and written informed consent was obtained from each enrolled patient.

Broad and strong memory CD4+ and CD8+ T cells induced by SARS-CoV-2 in UK convalescent individuals following COVID-19.

The development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and therapeutics will depend on understanding viral immunity. We studied T cell memory in 42 patients following recovery from COVID-19 (28 with mild disease and 14 with severe disease) and 16 unexposed donors, using interferon-γ-based assays with peptides spanning SARS-CoV-2 except ORF1. The breadth and magnitude of T cell responses were significantly higher in severe as compared with mild cases. Total and spike-specific T cell responses correlated with spike-specific antibody responses. We identified 41 peptides containing CD4+ and/or CD8+ epitopes, including six immunodominant regions. Six optimized CD8+ epitopes were defined, with peptide-MHC pentamer-positive cells displaying the central and effector memory phenotype. In mild cases, higher proportions of SARS-CoV-2-specific CD8+ T cells were observed. The identification of T cell responses associated with milder disease will support an understanding of protective immunity and highlights the potential of including non-spike proteins within future COVID-19 vaccine design.

Calculation of immune cell proportion from batch tumor gene expression profile based on support vector regression

In addition to tumor cells, a large number of immune cells are found in the tumor microenvironment (TME) of cancer patients. Tumor-infiltrating immune cells play an important role in tumor progression and patient outcome. We improved the relative proportion estimation algorithm of immune cells based on RNA-seq gene expression profiling and solved the multiple linear regression model by support vector regression ([Formula: see text]-SVR). These steps resulted in increased robustness of the algorithm and more accurate calculation of the relative proportion of different immune cells in cancer tissues. This method was applied to the analysis of infiltrating immune cells based on 41 pairs of colorectal cancer tissues and normal solid tissues. Specifically, we compared the relative fractions of six types of immune cells in colorectal cancer tissues to those found in normal solid tissue samples. We found that tumor tissues contained a higher proportion of CD8 T cells and neutrophils, while B cells and monocytes were relatively low. Our pipeline for calculating immune cell proportion using gene expression profile data can be freely accessed from GitHub at https://github.com/gutmicrobes/EICS.git.

Regular Use of Depot Medroxyprogesterone Acetate Causes Thinning of the Superficial Lining and Apical Distribution of Human Immunodeficiency Virus Target Cells in the Human Ectocervix.

BackgroundThe hormonal contraceptive depot medroxyprogesterone acetate (DMPA) may be associated with an increased risk of acquiring human immunodeficiency virus (HIV). We hypothesize that DMPA use influences the ectocervical tissue architecture and HIV target cell localization.MethodsQuantitative image analysis workflows were developed to assess ectocervical tissue samples collected from DMPA users and control subjects not using hormonal contraception.ResultsCompared to controls, the DMPA group exhibited a significantly thinner apical ectocervical epithelial layer and a higher proportion of CD4+CCR5+ cells with a more superficial location. This localization corresponded to an area with a nonintact E-cadherin net structure. CD4+Langerin+ cells were also more superficially located in the DMPA group, although fewer in number compared to the controls. Natural plasma progesterone levels did not correlate with any of these parameters, whereas estradiol levels were positively correlated with E-cadherin expression and a more basal location for HIV target cells of the control group.ConclusionsDMPA users have a less robust epithelial layer and a more apical distribution of HIV target cells in the human ectocervix, which could confer a higher risk of HIV infection. Our results highlight the importance of assessing intact genital tissue samples to gain insights into HIV susceptibility factors.

Multidimensional study of the heterogeneity of leukemia cells in t(8;21) acute myelogenous leukemia identifies the subtype with poor outcome

t(8;21)(q22;q22) acute myelogenous leukemia (AML) is morphologically characterized by a continuum of heterogeneous leukemia cells from myeloblasts to differentiated myeloid elements. Thus, t(8;21) AML is an excellent model for studying heterogeneous cell populations and cellular evolution during disease progression. Using integrative analyses of immunophenotype, RNA-sequencing (RNA-seq), and single-cell RNA-sequencing (scRNA-seq), we identified three distinct intrapatient leukemic cell populations that were arrested at different stages of myeloid differentiation: CD34+CD117dim blasts, CD34+CD117bri blasts, and abnormal myeloid cells with partial maturation (AM). CD117 is also known as c-KIT protein. CD34+CD117dim cells were blocked in the G0/G1 phase at disease onset, presenting with the regular morphology of myeloblasts showing features of granulocyte-monocyte progenitors (GMP), and were drug-resistant to chemotherapy. Genes associated with cell migration and adhesion (LGALS1, EMP3, and ANXA2) were highly expressed in the CD34+CD117dim population. CD34+CD117bri blasts were blocked a bit later than the CD34+CD117dim population in the hematopoietic differentiation stage and displayed high proliferation ability. AM cells, which bear abnormal myelocyte morphology, especially overexpressed granule genes AZU1, ELANE, and PRTN3 and were sensitive to chemotherapy. scRNA-seq at different time points identified CD34+CD117dim blasts as an important leukemic cluster that expanded at postrelapse refractory stage after several cycles of chemotherapy. Patients with t(8;21) AML with a higher proportion of CD34+CD117dim cells had significantly worse clinical outcomes than those with a lower CD34+CD117dim proportion. Univariate and multivariate analyses identified CD34+CD117dim proportion as an independent factor for poor disease outcome. Our study provides evidence for the multidimensional heterogeneity of t(8;21)AML and may offer new tools for future disease stratification.

Feeding Buttermilk-Derived Choline Forms During Gestation and Lactation Modulates Ex Vivo T-Cell Response in Rat Dams

Buttermilk contains a mixture of choline forms; it is high in phosphatidylcholine (PC) and sphingomyelin (SM), which could have an impact on immune system development and function. We aimed to determine the effect of feeding buttermilk-derived choline forms during pregnancy and lactation on maternal immune function. Sprague Dawley dams (n=8 per diet) were randomly assigned midway through pregnancy (10 d of gestation) to 1 of 3 experimental diets, containing 1.7g/kg choline: control [100% free choline (FC)]; buttermilk [37%PC, 34% SM, 17% glycerophosphocholine (GPC), 7% FC, 5% phosphocholine]; or placebo (50%PC, 25% FC, 25% GPC). Dams consumed the same diet until the end of the lactation period (21 d after parturition). Cell phenotypes and cytokine production by mitogen-stimulated splenocytes were measured and compared using 1-factor ANOVA test in order to asses the effect of diet on immune fuction of lactating dams (main outcome). After ConA stimulation, splenocytes from dams in the buttermilk group produced more IL-2 (30%), TNF-α (30%), and IFN-γ (42%) compared with both the placebo and control diets. Placebo-fed dams had a higher proportion of CD8+cells expressing CD152+ (22%) in spleen, and splenocytes from dams that were fed the buttermilk and the placebo diets produced about 50% and 53% more IL-10 after LPS and OVA stimulation, respectively, compared with the control group. Feeding buttermilk-derived choline forms during pregnancy and lactation had a beneficial impact on the immune system of Sprague Dawley rat dams, especially on T-cell function.

Recombinant invasive Lactobacillus plantarum expressing the Eimeria tenella fusion gene TA4 and AMA1 induces protection against coccidiosis in chickens

Coccidiosis is an intestinal parasitic disease that is caused by Eimeria tenella and other species, and it seriously restricts the economic development of the broiler breeding industry. In this study, a recombinant Lactobacillus plantarum with an invasive effect was constructed, and it expressed the TA4-AMA1 protein of E. tenella. After oral immunization with recombinant L. plantarum, specific humoral and mucosal immune levels were measured by indirect ELISA, and the differentiation of T cells was analysed by flow cytometry. After challenge with sporulated oocysts, the body weight, oocyst shedding and cecum lesions of the chicken were evaluated. The results indicated that chickens immunized with recombinant invasive L. plantarum produced higher levels of specific antibodies in the serum than did the non-immunized controls, and the secretory IgA (sIgA) levels were increased in the intestinal washes compared to those of the controls (P < 0.05). Flow cytometry showed that recombinant invasive L. plantarum significantly stimulated T cell differentiation compared to the PBS group (P < 0.01, P < 0.001), and a higher proportion of CD4+ and CD8+ T cells were detected in peripheral blood. Moreover, the lesion scores and histopathological caecum sections showed that immunizing chickens with recombinant invasive L. plantarum can significantly relieve pathological damage in the cecum (P < 0.01), and the relative body weight gain was 89.64 %, which was higher than the 79.83 % gain in the chickens immunized with non-invasive L. plantarum. After the challenge, faeces from ten chickens in each group were collected between 4 and 7 days, and the oocysts per gram (OPG) was determined by the McMaster technique. The data indicated that oocysts in the faeces of chickens immunized with the recombinant invasive L. plantarum were significantly lower than those of the controls (P < 0.01). The results suggest that recombinant invasive L. plantarum effectively activated immune responses against E. tenella infection and can be used as a candidate vaccine against E. tenella infection.

Deep immune profiling of patients treated with lenalidomide and dexamethasone with or without daratumumab

CD38-targeted antibody, daratumumab, is approved for the treatment of multiple myeloma (MM). Phase 1/2 studies GEN501/SIRIUS revealed a novel immunomodulatory mechanism of action (MOA) of daratumumab that enhanced the immune response, reducing natural killer (NK) cells without affecting efficacy or safety. We further evaluated daratumumab’s effects on immune cells in whole blood samples of relapsed/refractory MM patients from both treatment arms of the phase 3 POLLUX study (lenalidomide/dexamethasone [Rd] or daratumumab plus Rd [D-Rd]) at baseline (D-Rd, 40; Rd, 45) and after 2 months on treatment (D-Rd, 31; Rd, 33) using cytometry by time-of-flight. We confirmed previous reports of NK cell reduction with D-Rd. Persisting NK cells were phenotypically distinct, with increased expression of HLA-DR, CD69, CD127, and CD27. The proportion of T cells increased preferentially in deep responders to D-Rd, with a higher proportion of CD8+ versus CD4+ T cells. The expansion of CD8+ T cells correlated with clonality, indicating generation of adaptive immune response with D-Rd. D-Rd resulted in a higher proportion of effector memory T cells versus Rd. D-Rd reduced immunosuppressive CD38+ regulatory T cells. This study confirms daratumumab’s immunomodulatory MOA in combination with immunomodulatory drugs and provides further insight into immune cell changes and activation status following daratumumab-based therapy.

Mucosal correlates associated with natural regression of HPV-associated dysplasia

Abstract Background Anal HPV infection and associated pre-cancerous changes, known as anal intraepithelial neoplasia (AIN), are common among men who have sex with men (MSM). While natural regression of AIN is often observed, there are currently no predictors for disease outcomes. Therefore, we assessed mucosal immune and microbiological correlates of natural AIN regression. Methods Fifty-five HIV-infected, ART-treated MSM were recruited, of whom 26 had confirmed AIN. The microbiome was defined via qPCR and 16s sequencing of anal swabs; biopsies were collected from both healthy and AIN-confirmed sites by high-resolution anoscopy, and lymphocyte populations were defined by flow cytometric analysis including CD38 and HLA-DR as activation markers. AIN regressors vs non-regressors were compared by Mann-Whitney (SPSS). Results AIN regression was observed in 15/26 (58%) participants. Regression was associated with a higher proportion of CD8+ T cells (p= 0.006), and AIN regressors had significantly higher levels of both activated CD8+ (p= 0.023; 44.5% vs 27.9%) and activated CD4+ T cells (p=0.023; 20.4% vs 9.81%) compared to non-regressors. Interestingly, AIN regressors had reduced microbiome diversity (p=0.026; 241 vs 284 OTUs) and a trend towards a lower bacterial load (p=0.059). While age was similar between groups, AIN regressors had been living with HIV for a shorter time (p=0.023). No differences were observed between groups in T cells derived from AIN-free anal mucosa. Conclusions AIN-specific immune activation was associated with subsequent regression of AIN. Given that AIN non-regressors had greater anal microbiome diversity, defining key bacterial species and their role in HPV pathogenesis may merit further investigation.

Changes in the Vα7.2+ CD161++ MAIT cell compartment in early pregnancy are associated with preterm birth in HIV-positive women.

Human immunodeficiency virus (HIV) infection is associated with an increased risk of adverse pregnancy outcomes, including preterm birth (PTB), despite viral suppression with antiretroviral therapy. Mucosal-associated invariant T (MAIT) cells are an immune cell subset involved in antimicrobial immunity at mucosal surfaces. MAIT cells have been found at the maternal-foetal interface, and MAIT cells are typically depleted early in HIV infection. We aimed to investigate changes in MAIT cells in relation to maternal HIV/ART status and PTB. We conducted flow cytometric analysis of peripheral blood samples from 47 HIV-positive (HIV+) and 45 HIV-negative (HIV-) pregnant women enrolled in a prospective pregnancy cohort study in Soweto, South Africa. Frequencies of Vα7.2+ CD161++ MAIT cells and proportions of CD4+ , CD8+ and double-negative MAIT cells were compared between women with and without HIV infection, and between women with and without PTB or spontaneous preterm labour (Sp-PTL). Although overall MAIT cell frequencies were the same between HIV+ and HIV- patients, HIV+ patients had a higher proportion of CD8+ MAIT cells in the first two trimesters. Women with PTB and Sp-PTL also had a higher proportion of CD8+ MAIT cells in the first trimester compared to women without these outcomes. The association between changes in MAIT cell subsets and PTB/Sp-PTL was present in both HIV+ and HIV- women, and an additive effect on MAIT cell subsets was seen in women with both HIV infection and PTB. Interactions between HIV-related and pregnancy-related changes in MAIT cell subsets and distribution may lead to imbalances in peripheral MAIT cell subsets in early pregnancy. This may contribute to the increased risk of PTB in HIV+ patients by altering the overall functionality of the peripheral MAIT cell compartment.

Abstract B08: C-C chemokine receptor 4 (CCR4) antagonism enhances the effectiveness of checkpoint Inhibition in mouse tumor models

Abstract Introduction: Chemokines and their receptors influence many of the hallmark processes in cancer: they act not only on infiltrating leukocytes, but also on fibroblasts, endothelial cells, and directly on some types of tumor cells. C-C chemokine receptor 4 (CCR4) and its ligands have been found to be highly expressed in multiple types of human tumors and are associated with poor prognosis. CCR4 antagonism has been demonstrated to reduce tumor growth in various mouse tumor models. Here we assess small-molecule inhibition of CCR4 as a therapeutic agent to potentiate the effects of checkpoint inhibitors in the CT26 and KCM tumor models. Methods: The subcutaneous CT26 colon cancer model and the orthotopic KCM pancreatic cancer model were used to assess the effects of a CCR4 inhibitor, CCX6239, in combination with anti-CTLA-4 antibody. CT26 cells were implanted into the flanks of 9wk female Balb/c mice. Mice were randomized into study groups based on the tumor sizes on day 6, and dosing of both CCX6239 and anti-CTLA-4 started on day 7. For the orthotopic pancreatic cancer model, KCM cells were implanted directly into the pancreas, and dosing of CCX6239 and anti-CTLA-4 also began on day 7. CCX6239 was dosed orally twice daily at 30mg/kg, and anti-CTLA-4 was dosed IP on days 7, 11 and 15 at 100μg/mouse. Results: Blockade of CCR4 appreciably enhanced the therapeutic effects of anti-CTLA-4 in both models. Combined anti-CTLA-4/CCR4 inhibitor significantly decreased tumor size and increased the proportion of long-term survivors in the CT26 model. The antitumor response was CT26-specific; long-term survivors were resistant to reinoculation with CT26 cells (without further dosing of either drug), but 4T1 breast tumors grew well upon challenge of CT26 survivors. Mice with tumor regression exhibited a high proportion of CD8 T cells that recognized a CT26-specific neoantigen, as illustrated by AH1 peptide-MHC tetramer staining. Although long-term survival has not yet been examined in the KCM model, CCX6239 alone significantly reduced tumor burden in 3 independent studies. Anti-CTLA-4 alone provided substantial inhibition of tumor growth in this model, which was further enhanced by CCX6239. Summary: A specific CCR4 small-molecule inhibitor enhanced the effectiveness of anti-CTLA-4 in 2 preclinical models, suggesting that targeting CCR4 may be a viable clinical approach for combinatorial treatment with checkpoint blockers. Citation Format: Shijie “Chris” Li, James J. Campbell, Linda S. Ertl, Zhenhua Miao, Vicky Chhina, Alice Kumamoto, Simon Yau, Ton Dang, Penglie Zhang, Thomas J. Schall, Rajinder Singh. C-C chemokine receptor 4 (CCR4) antagonism enhances the effectiveness of checkpoint Inhibition in mouse tumor models [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B08.