Numbers Of CD8 Research Articles

T cell Dissimilarities in B Cell Activating Factor-Deficient Versus B Cell Activating Factor Receptor 3-Deficient Systemic Lupus Erythematosus-Prone NZM 2328 Mice as Contributors to Their Divergent Clinical Outcomes.

We assessed the contributions of B cell and T cell subsets to the disparate clinical outcomes in NZM.Baff-/- and NZM.Br3-/- mice. We assessed in NZM wild-type, NZM.Baff-/-, and NZM.Br3-/- mice numbers and percentages of B cells and subsets, T cells and subsets, and in vivo proliferation and survival of forkhead box P3 (Foxp3)+ cells by fluorescence-activated cell sorting. Relationships between percentages of Foxp3+ cells and numbers of CD19+ and CD4+ cells were assessed by linear regressions. In each age and sex cohort, percentages and numbers of CD19+ cells were similar in NZM.Baff-/- and NZM.Br3-/- mice. Percentages of CD3+ and CD4+ cells were greater in NZM.Br3-/- than in NZM.Baff-/- mice, with the CD4 to CD3 cell ratios being greater in NZM.Br3-/- than in NZM.Baff-/- mice and percentages of Foxp3+ cells in NZM.Br3-/- mice being lower than in NZM.Baff-/- mice. Percentages of Foxp3+ cells correlated positively with CD19+ cells in NZM.Baff-/- mice but negatively in NZM.Br3-/- mice. In vivo proliferation and survival of Foxp3+ cells were lower in NZM.Baff-/- mice than in NZM.Br3-/- mice. Differences between NZM.Baff-/- and NZM.Br3-/- mice in Foxp3+ cells and their relationships with CD19+ cells may have more to do with their divergent clinical outcomes than do differences in numbers of B cells. These unexpected findings suggest that B cell activating factor (BAFF)-B cell maturation antigen (BCMA) or BAFF-Transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI) interactions may help drive development of clinical systemic lupus erythematosus (SLE) even under conditions of considerable B cell depletion. Insufficient blocking of BAFF-BCMA and BAFF-TACI interactions may lie at the heart of incomplete clinical response to BAFF-targeting agents in human SLE.

Alterations in the innate and adaptive immune system in a real-world cohort of multiple sclerosis patients treated with ocrelizumab

B cell depletion by the anti-CD20 antibody ocrelizumab is effective in relapsing-remitting (RR) and primary progressive (PP) multiple sclerosis (MS). We investigated immunological changes in peripheral blood of a real-world MS cohort after 6 and 12 months of ocrelizumab.All RRMS and most PPMS patients (15/20) showed treatment response. Ocrelizumab not only reduced CD20+ B cells, but also numbers of CD20+ T cells. Absolute numbers of monocytes, dendritic cells and CD8+ T cells were increased, while CD56hi natural killer cells were reduced after ocrelizumab. The residual B cell population shifted towards transitional and activated, IgA+ switched memory B cells, double negative B cells, and antibody-secreting cells. Delaying the treatment interval by 2–3 months increased mean B cell frequencies and enhanced naive B cell repopulation. Ocrelizumab reduced plasma levels of interleukin(IL)-12p70 and interferon(IFN)-α2.These findings will contribute to understanding ineffective treatment responses, dealing with life-threatening infections and further unravelling MS pathogenesis.

Brain resident memory T cells rapidly expand and initiate neuroinflammatory responses following CNS viral infection

The contribution of circulating verses tissue resident memory T cells (TRMs) to clinical neuropathology is an enduring question due to a lack of mechanistic insights. The prevailing view is TRMs are protective against pathogens in the brain. However, the extent to which antigen-specific TRMs induce neuropathology upon reactivation is understudied. Using the described phenotype of TRMs, we found that brains of naïve mice harbor populations of CD69+ CD103- T cells. Notably, numbers of CD69+ CD103- TRMs rapidly increase following neurological insults of various origins. This TRM expansion precedes infiltration of virus antigen-specific CD8 T cells and is due to proliferation of T cells within the brain. We next evaluated the capacity of antigen-specific TRMs in the brain to induce significant neuroinflammation post virus clearance, including infiltration of inflammatory myeloid cells, activation of T cells in the brain, microglial activation, and significant blood brain barrier disruption. These neuroinflammatory events were induced by TRMs, as depletion of peripheral T cells or blocking T cell trafficking using FTY720 did not change the neuroinflammatory course. Depletion of all CD8 T cells, however, completely abrogated the neuroinflammatory response. Reactivation of antigen-specific TRMs in the brain also induced profound lymphopenia within the blood compartment. We have therefore determined that antigen-specific TRMs can induce significant neuroinflammation, neuropathology, and peripheral immunosuppression. The use of cognate antigen to reactivate CD8 TRMs enables us to isolate the neuropathologic effects induced by this cell type independently of other branches of immunological memory, differentiating this work from studies employing whole pathogen re-challenge. This study also demonstrates the capacity for CD8 TRMs to contribute to pathology associated with neurodegenerative disorders and long-term complications associated with viral infections. Understanding functions of brain TRMs is crucial in investigating their role in neurodegenerative disorders including MS, CNS cancers, and long-term complications associated with viral infections including COVID-19.

Polymorphisms within Autophagy-Related Genes as Susceptibility Biomarkers for Multiple Myeloma: A Meta-Analysis of Three Large Cohorts and Functional Characterization.

Multiple myeloma (MM) arises following malignant proliferation of plasma cells in the bone marrow, that secrete high amounts of specific monoclonal immunoglobulins or light chains, resulting in the massive production of unfolded or misfolded proteins. Autophagy can have a dual role in tumorigenesis, by eliminating these abnormal proteins to avoid cancer development, but also ensuring MM cell survival and promoting resistance to treatments. To date no studies have determined the impact of genetic variation in autophagy-related genes on MM risk. We performed meta-analysis of germline genetic data on 234 autophagy-related genes from three independent study populations including 13,387 subjects of European ancestry (6863 MM patients and 6524 controls) and examined correlations of statistically significant single nucleotide polymorphisms (SNPs; p < 1 × 10-9) with immune responses in whole blood, peripheral blood mononuclear cells (PBMCs), and monocyte-derived macrophages (MDM) from a large population of healthy donors from the Human Functional Genomic Project (HFGP). We identified SNPs in six loci, CD46, IKBKE, PARK2, ULK4, ATG5, and CDKN2A associated with MM risk (p = 4.47 × 10-4-5.79 × 10-14). Mechanistically, we found that the ULK4rs6599175 SNP correlated with circulating concentrations of vitamin D3 (p = 4.0 × 10-4), whereas the IKBKErs17433804 SNP correlated with the number of transitional CD24+CD38+ B cells (p = 4.8 × 10-4) and circulating serum concentrations of Monocyte Chemoattractant Protein (MCP)-2 (p = 3.6 × 10-4). We also found that the CD46rs1142469 SNP correlated with numbers of CD19+ B cells, CD19+CD3- B cells, CD5+IgD- cells, IgM- cells, IgD-IgM- cells, and CD4-CD8- PBMCs (p = 4.9 × 10-4-8.6 × 10-4) and circulating concentrations of interleukin (IL)-20 (p = 0.00082). Finally, we observed that the CDKN2Ars2811710 SNP correlated with levels of CD4+EMCD45RO+CD27- cells (p = 9.3 × 10-4). These results suggest that genetic variants within these six loci influence MM risk through the modulation of specific subsets of immune cells, as well as vitamin D3-, MCP-2-, and IL20-dependent pathways.

Ophiopogonin D attenuates the progression of murine systemic lupus erythematosus by reducing B cell numbers.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by immune abnormalities leading to multi-organ damage. The activation of autoreactive B cell differentiation will lead to the production of pathogenic autoantibodies, contributing to the development of SLE. However, the effects of Ophiopogonin D (OP-D) on B cell activation and autoantibody production as well as renal injury in the pathogenesis of SLE remain unclear. MRL/lpr mice, one of the most commonly used animal models of SLE, were intragastrically administered with 5 mg/kg/d OP-D at 17 weeks of age for 3 weeks. The survival rates of mice in each group were monitored for 6 weeks until 23 weeks of age. Proteinuria and serum creatinine levels were measured. Serum levels of immunoglobulin (Ig)G, IgM, and anti-dsDNA autoantibodies were detected by enzyme-linked immunosorbent assay. Numbers of CD19+ B cells in the blood, spleen and bone marrow and numbers of splenic germinal center (GC) B cells were calculated by using flow cytometry. OP-D treatment prolonged survival in MRL/lpr mice. OP-D treatment reduced proteinuria and serum creatinine levels as well as mitigated renal pathological alternation in MRL/lpr mice. Furthermore, serum levels of IgG, IgM, and anti-dsDNA autoantibodies were reduced by OP-D treatment. OP-D lessened not only CD19+ B cells in the spleen and bone marrow but also plasma cells that secreted anti-dsDNA autoantibodies, IgG and IgM in the spleen and bone marrow. OP-D ameliorated the progression of SLE by inhibiting the secretion of autoantibodies though reducing B cell numbers.

CD11b mediates hypertensive cardiac remodeling by regulating macrophage infiltration and polarization

IntroductionLeukocyte infiltration is an early event during cardiac remodeling frequently leading to heart failure (HF). Integrins mediate leukocyte infiltration during inflammation. However, the importance of specific integrins in hypertensive cardiac remodeling is still unclear. ObjectivesTo elucidate the significance of CD11b in hypertensive cardiac remodeling. MethodsAngiotensin (Ang II) or deoxycorticosterone acetate (DOCA)-salt was used to induce cardiac remodeling in mice of gene knockout (KO), bone marrow (BM) chimera, and the CD11b neutralizing antibody or agonist leukadherin-1 (LA1) treatment. ResultsOur microarray data showed that integrin subunits Itgam (CD11b) and Itgb2 (CD18) were the most highly upregulated in Ang II-infused hearts. CD11b expression and CD11b/CD18+ myelomonocytes were also time-dependently increased. KO or pharmacological blockade of CD11b greatly attenuated cardiac remodeling and macrophage infiltration and M1 polarization induced by Ang II or DOCA-salt. This protection was verified in wild-type mice transplanted with CD11b-deficient BM cells. Conversely, administration of CD11b agonist LA1 showed the opposite effects. Further, CD11b KO reduced Ang II-induced macrophage adhesion and M1 polarization, leading to reduction of cardiomyocyte enlargement and fibroblast differentiation in vitro. The numbers of CD14+CD11b+CD18+ monocytes and CD15+CD11b+CD18+ granulocytes were obviously higher in HF patients than in normal controls. ConclusionOur data demonstrate an important role of CD11b+ myeloid cells in hypertensive cardiac remodeling, and suggest that HF may benefit from targeting CD11b.

B Cell and T Cell Dissimilarities in BAFF-Deficient versus BR3-Deficient C57BL/6 Mice.

BAFF is a potent B cell survival and differentiation factor with three receptors, TACI, BCMA, and BR3. B cells are greatly reduced in BAFF-deficient mice, and among mice deficient in a single BAFF receptor, B cell reduction is characteristic only of BR3-deficient mice. Nevertheless, there may be important differences between BR3-deficient mice, in which interactions between BAFF and only BR3 are abrogated, and BAFF-deficient mice, in which interactions between BAFF and all its receptors are abrogated. We demonstrate that: 1) the numbers of CD19+ cells in C57BL/6 (B6).Baff-/- and B6.Br3-/- mice diverge as the mice age; 2) the distribution of B cell subsets significantly differ between B6.Baff-/- and B6.Br3-/- mice regardless of age or sex; 3) the relationships of CD3+ and CD4+ cells to B cells vastly differ between B6.Baff-/- and B6.Br3-/- mice as a function of age and sex; 4) the numbers and percentages of CD4+Foxp3+ and CD4+CD25+Foxp3+ are greater in B6.Baff-/- mice than in B6.Br3-/- mice; and 5) for any given number of CD19+ cells or CD4+ cells, percentages of Foxp3+ cells and CD4+CD25+Foxp3+ cells are lower in B6.Br3-/- mice than in B6.Baff-/- mice, with proliferation of these cells being greater, and survival being lesser, in B6.Br3-/- mice than in B6.Baff-/- mice. Collectively, these observations raise the possibility that interactions between TACI and/or BCMA and BAFF modulate expression of B cell subsets and Foxp3+ cells and may help explain prior enigmatic observations of autoimmunity and autoimmune disease in mice despite the absence of functional engagement of BR3 by BAFF.

FcγRIIB inhibits inflammation in a murine model of psoriasis

BackgroundPsoriasis is a chronic, inflammatory cutaneous disease. FcγRIIB is a low-affinity receptor for the IgG Fc fragment that provides a negative feedback pathway to down-regulate B-cell antigen receptor signaling. ObjectiveThe aim of this study was to investigate the role of FcγRIIB in the development of murine imiquimod (IMQ)-induced, psoriasis-like skin inflammation. MethodsThe experimental psoriasis-like skin inflammation was induced by the topical application of IMQ to the ears of FcγRIIB deficient (FcγRIIB-/-) and wild-type (WT) mice. After 6 days, epidermal thickness and inflammatory cell infiltration of the skin were histopathologically assessed and cytokine and chemokine expression levels were measured with RT-PCR. ResultsSkin inflammation was significantly worse in FcγRIIB-/- mice than WT mice. In the skin, the numbers of Gr-1+ neutrophils, CD11c+ dendritic cells, and Foxp3+ T cells were significantly higher in FcγRIIB-/- mice than WT mice. In the spleen, the numbers of CD25+Foxp3+ T cells and CD19+IL-10+ B cells were also significantly higher in FcγRIIB-/-mice than WT mice. The mRNA expression of Il-6, Il-17a, and Il-23a was significantly enhanced in FcγRIIB-/- mice. An adoptive transfer of splenic leukocytes from FcγRIIB-/- mice into WT mice also exacerbated skin inflammation compared to WT mice that received splenic leukocytes from WT mice. Intravenous immunoglobulin significantly reduced skin inflammation in WT mice, but this improvement was not observed in FcγRIIB-/- mice. ConclusionThese results indicate that FcγRIIB likely plays a suppressive role in IMQ-induced, psoriasis-like skin inflammation. Furthermore, signal modulation via FcγRIIB is a potential therapeutic target for psoriasis.

Cytokines and Immune Cells Profile in Different Tissues of Rodents Induced by Environmental Enrichment: Systematic Review.

Environmental Enrichment (EE) is based on the promotion of socio-environmental stimuli, which mimic favorable environmental conditions for the practice of physical activity and health. The objective of the present systematic review was to evaluate the influence of EE on pro-and anti-inflammatory immune parameters, but also in cell activation related to the innate and acquired immune responses in the brain and peripheral tissues in rodents. Three databases [PubMed (2209 articles), Scopus (1154 articles), and Science Direct (1040 articles)] were researched. After applying the eligibility criteria, articles were selected for peer review, independently, as they were identified by September 2021. The protocol for this systematic review was registered in the PROSPERO. Of the 4417 articles found, 16 were selected for this systematic review. In the brain, EE promoted a reduction in proinflammatory cytokines and chemokines. In the blood, EE promoted a higher percentage of leukocytes, an increase in CD19+ B lymphocytes, and the proliferation of Natura Killer (NK cells). In the bone marrow, there was an increase in the number of CD27− and CD11b+ mature NK cells and a reduction in CD27− and CD11b+ immature Natural Killer cells. In conclusion, EE can be an immune modulation approach and plays a key role in the prevention of numerous chronic diseases, including cancer, that have a pro-inflammatory response and immunosuppressive condition as part of their pathophysiology.

CT-016 Prognostic Role of Lymphocyte-to-Monocyte Ratio in Patients Treated With CAR-T for Aggressive Lymphoma

Low absolute lymphocyte-to-monocyte ratio (ALC/AMC) predicts decreased survival in aggressive lymphoma (NHL) patients (pts) receiving chemotherapy and autologous stem cell transplantation (ASCT). We report the clinical significance of ALC/AMC and associated cellular phenotype changes in pts receiving chimeric antigen receptor T-cell (CAR-T) therapy. We conducted a retrospective chart review of all pts who received axicabtagene ciloleucel for NHL at Mayo Clinic, Rochester, between 6/2016 and 12/2020. ALC and AMC were obtained from clinical labs before lymphodepletion chemotherapy (LD). A receiver operator curve was generated using nominal logistic regression on ALC/AMC to predict complete remission (CR). Survivals were calculated using the Kaplan-Meier method. Blood immune phenotypes were assayed by multiparametric flow cytometry. Low ALC/AMC (≤0.8, n=29) prior to LD was associated with a lower CR rate (AUC=0.68, P=0.0004). Baseline characteristics were similar between the low and high ALC/AMC groups (>0.8, n=52), except for the use of prior ASCT and bridging therapy. The low ALC/AMC group also had higher C-reactive protein (CRP) on the day of CAR-T infusion and was associated with shorter event-free survival (EFS) and overall survival (OS) (EFS: 2.6 vs. 6.4 months, P<0.0001; OS: 5.3 months vs. not reached, P=0.0006). The prognostic association remained statistically significant in multivariate analysis that included prior ASCT, bridging therapy, and CRP. Compared with the high ALC/AMC group, the low ALC/AMC group had decreased CD4 effector memory T cells and increased CD16+CCR2+ monocytes (n=26). In addition, when comparing pts who achieved CR initially and relapsed versus those who maintained durable CR for 6 months or longer, there was a difference in these phenotypes as well as the number of CD27+CD45RA+CD62L+ CD8 T cells and PD-1+TIGIT+ T cells. ALC/AMC is a clinically accessible test that is strongly associated with CAR-T response and survival. Immune characterization revealed that the biologic effect is not just associated with cell numbers. Phenotypes, such as monocytes with inflammatory capacity and T-cell subsets, may further distinguish between primary refractory disease, early relapse, and durable response. These data could inform future therapeutic strategies to improve clinical outcomes with CAR-T.

CT-009 Prognostic Role of Lymphocyte to Monocyte Ratio in PTS Treated With CAR-T for Aggressive Lymphoma

Low absolute lymphocyte to monocyte ratio (ALC/AMC) predicts decreased survival in aggressive lymphoma (NHL) patients (pts) receiving chemotherapy and ASCT. We report the clinical significance of ALC/AMC and associated cellular phenotype changes in pts receiving chimeric antigen receptor T-cell (CART) therapy. We conducted a retrospective chart review of all pts who received axicabtagene ciloleucel for NHL at Mayo Clinic, Rochester between 6/2016 and 12/2020. ALC and AMC were obtained from the clinical lab before lymphodepletion chemotherapy (LD). The receiver operator curve was generated using nominal logistic regression on ALC/AMC to predict complete remission (CR). Survivals were calculated using the Kaplan- Meier method. Blood immune phenotypes were assayed by multiparametric flow. Low ALC/AMC (≤0.8, n=29) prior to LD was associated with a lower CR rate (AUC=0.68, p=0.0004). Baseline characteristics were similar between the low and high ALC/AMC group (>0.8, n=52), except for the use of prior ASCT and bridging therapy. The low ALC/AMC group also had higher CRP on the day of CAR-T infusion and was associated with shorter EFS and OS (EFS: 2.6 vs. 6.4 months, P<0.0001; OS: 5.3 months vs. not reached, P=0.0006), respectively. The prognostic association remained statistically significant on multivariate analysis that included prior ASCT, bridging therapy, and CRP. Compared to the high ALC/AMC group, the low ALC/AMC group had decreased CD4 Tem and increased CD16+CCR2+ monocytes (n=26). In addition, when comparing patients who achieved CR initially and relapsed versus those who maintained durable CR for 6 months or longer, there was a difference in these phenotypes as well as the number of CD27+CD45RA+CD62L+ CD8 T cells and PD-1+TIGIT+ T cells. ALC/AMC is a clinically accessible test that is strongly associated with CAR-T response and survival. Immune characterization revealed that the biological effect is not just associated with cell numbers. Phenotypes such as monocytes with inflammatory capacity and T cell subsets may further distinguish between primary refractory disease, early relapse, and durable response. These data could inform future therapeutic strategies to improve clinical outcomes with CAR-T.

Effects of oral immunonutrition on histological changes of inflammatory infiltration of the tumor microenvironment among patients with a new diagnosis of gastric cancer

ObjectivesWe assessed the effects of oral immunonutrition (OI) on the inflammatory infiltration of the tumor microenvironment (TME) of patients undergoing surgery for gastric cancer. MethodsWe analyzed patients at the time of their first gastric cancer diagnosis. We collected surgical tissue specimens (stomach), and performed an immunohistochemical analysis to evaluate the inflammatory infiltration of the TME. Patients receiving OI were compared with patients receiving standard oral nutritional supplements and no nutritional support. ResultsWe enrolled 12 patients with gastric cancer in the study. The median body weight loss was 5.6%. Four patients received OI, five patients received standard nutritional supplement, and three patients received no nutritional supplementation. No difference in age, body mass index (BMI), and body weight loss was observed between the three groups. The OI group showed a tendency of increased number of T-lymphocyte cluster of differentiation (CD) 8+ compared with the other groups, as well as the number of CD83+ and CD68+. The absence of F4/80+ cells was documented only in the TME of the OI group, where a linear positive correlation was present between lymphocytes CD4+ and CD8+ (R = 0.48), and between CD4+ and CD83+ (R = 0.89), although not statistically significant. In the OI group, we observed a positive correlation (not significant) between the number of lymphocytes CD8+ and macrophages CD68+ (R = 0.70; P = 0.30). A strong significant correlation was documented between CD68+ and CD40+ (R = 0.99; P = 0.01), but this correlation did not reach the significance among the patients of the other two groups (R = 0.60; P = 0.116). ConclusionsThe administration of OI in patients with gastric cancer might determine changes in inflammatory patterns of the TME.

An Immunohistochemical study of CD83 positive dendritic cell density in human benign and malignant uterine specimens

Introduction and Aim: Dendritic cells (DCs) are heterogenous group of accessory cells that function as specialized forms of antigen-presenting cells in human body. A thorough knowledge of the DC population of the human uterus, especially the CD83 population would be very useful for an effective understanding of the immune protection of the endometrium during different phases of menstrual cycle and in the pathological conditions of the uterus. Materials and Methods: A prospective study was conducted in a tertiary care referral medical college hospital in South India. Women in the age group of 35 to 50 years, who underwent hysterectomy were included in the study. Immunohistochemical study on the presence of mature CD83+DCs was carried out in the processed uterine specimens. The number of CD83 cells/20 high power fields in each of the specimen was calculated and reviewed by two independent reviewers. Results: About 43 hysterectomy specimens obtained from patients undergoing hysterectomy for benign and malignant conditions of uterus were included in the study. Fibroid uterus was the most common indication for hysterectomy. The minimum and maximum DCs were 12 and 720 DCs per 20 HPF respectively, with an overall mean of 109.28. The mean DCs amongst benign specimens was 1.2 DCs and in the malignant specimens was 22.65 DCs per HPF, with a P value of 0.0001. Conclusion: Mature dendritic cells are seen in abundance in malignant and pre-malignant tissues of human uterus. A reduction in number of CD83+ DCs was observed in patients with proliferative and secretory endometrium.

A local human Vδ1 T cell population is associated with survival in nonsmall-cell lung cancer

Murine tissues harbor signature γδ T cell compartments with profound yet differential impacts on carcinogenesis. Conversely, human tissue-resident γδ cells are less well defined. In the present study, we show that human lung tissues harbor a resident Vδ1 γδ T cell population. Moreover, we demonstrate that Vδ1 T cells with resident memory and effector memory phenotypes were enriched in lung tumors compared with nontumor lung tissues. Intratumoral Vδ1 T cells possessed stem-like features and were skewed toward cytolysis and helper T cell type 1 function, akin to intratumoral natural killer and CD8+ T cells considered beneficial to the patient. Indeed, ongoing remission post-surgery was significantly associated with the numbers of CD45RA−CD27− effector memory Vδ1 T cells in tumors and, most strikingly, with the numbers of CD103+ tissue-resident Vδ1 T cells in nonmalignant lung tissues. Our findings offer basic insights into human body surface immunology that collectively support integrating Vδ1 T cell biology into immunotherapeutic strategies for nonsmall cell lung cancer.

Clinical and Pathological Implications of Increases in Tonsillar CD19+CD5+ B Cells, CD208+ Dendritic Cells, and IgA1-positive Cells of Immunoglobulin A Nephropathy

Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy (IgAN). However, the relationship between tonsillar immunity and IgAN is still unclear. A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital. B cells, dendritic cells (DCs), and IgA1 positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry. Correlations between these cells and clinicopathologic features were evaluated. CD19+CD5+ B cells were predominantly located in germinal centers and mantle zones of lymphoid follicles, the CD208+ DCs were distributed in the interfollicular and subepithelial area, and IgA1-positive cells were predominantly detected in mantle zones of lymphoid follicles and subepithelial tissues. The numbers of CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues from IgAN patients were significantly higher than those in the normal controls (P<0.01, respectively). CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues were significantly associated with 24-h proteinuria levels and tubular atrophy/interstitial fibrosis of IgAN. CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues might be involved in the pathogenesis of IgAN.

Value of Autoantibody Expression During Long-Term Follow-Up in Paediatric ALL Patients After Allogeneic Haematopoietic Stem Cell Transplantation.

Objectives: Chronic graft-versus-host disease (cGvHD) following haematopoietic stem cell transplantation (HSCT) shares many similarities with de novo autoimmune disorders, being associated with the presence of autoantibodies. However, data on the implication of autoantibodies in paediatric HSCT recipients are scarce. In this single-centre study of paediatric patients with acute lymphoblastic leukaemia (ALL) surviving longer than 3 months, our objectives were to evaluate autoantibody expression and investigate the correlation with cGvHD and immune reconstitution using serially monitored parameters.Methods: We investigated circulating autoantibodies together with cellular and humoral parameters [including major T- and B-cell subsets, natural killer (NK) cells, and immunoglobulin levels] in 440 samples from 74 patients (median age 10.9 years, range 2.7–22.2 years) serially during long-term follow-up of median 8 years (range 0.4–19.3 years). Evaluations comprised of patient and transplant characteristics, precisely reviewed details of National Institute of Health (NIH)-defined cGvHD, and outcome data such as relapse, overall survival (OS) and mortality. Analysis of these clinical parameters was performed to identify possible associations.Results: Autoantibodies were detected in 65% (48/74) of patients. Anti-nuclear antibodies were the most common, occurring in 75% (36/48) of patients with autoantibodies. When comparing demographic data and transplant characteristics, there were no significant differences between patients with and without autoantibody expression; 5-year OS was excellent, at 96.4 and 95.8%, respectively. Neither the expression of autoantibodies nor the occurrence of cGvHD correlated with significantly worse OS or relapse rate. Furthermore, there was no significant association between autoantibody profiles and the incidence, overall severity or organ involvement of cGvHD. Patients with autoantibodies showed significantly better immune reconstitution, with overall higher numbers of T cells, B cells, and serum immunoglobulins. In autoantibody-positive patients with cGvHD, autoantibody production positively correlated with the expansion of CD56+ NK cells (236.1 vs. 165.6 × 103 cells/mL, respectively; p = 0.023) and with signs of B-cell perturbation, such as higher CD21low B cells (23.8 vs. 11.8 × 103 cells/mL, respectively; p = 0.044) and a higher ratio of CD21low B cells/CD27+ memory B cells (1.7 vs. 0.4, respectively; p = 0.006) in comparison to autoantibody-positive patients without cGvHD. Furthermore, when assessing the correlation between autoantibody positivity and the activity of cGvHD at time of analysis, indicators of aberrant B-cell homeostasis were substantiated by a lower proportion of CD27+ memory B cells (9.1 vs. 14.9%, respectively; p = 0.028), a higher ratio of class-switched CD27+IgD−/CD27+ memory B cells (3.5 vs. 5.1%, respectively; p = 0.013), significantly elevated numbers of CD21low B cells (36.8 vs. 11.8 × 103 cells/mL, respectively; p = 0.013) and a higher ratio of CD21lowB cells/CD27+ memory B cells (2.4 vs. 0.4, respectively; p = 0.034) in the active vs. the no cGvHD group. We then assessed the potential role of autoantibody expression in the context of elevated CD19+CD21low B cells (cutoff >7%), a well-known marker of cGvHD. Surprisingly we found a significant higher proportion of those cases where elevated CD21low B cells correlated with active cGvHD in samples from the autoantibody-negative group vs. the antibody-positive group (82 vs. 47%, respectively; p = 0.0053).When comparing immune parameters of the large proportion of survivors (89%) with the small proportion of non-survivors (11%), data revealed normalisation within the B-cell compartment of survivors: there were increased numbers of CD27+ memory B cells (54.9 vs. 30.6 × 103 cells/mL, respectively; p = 0.05), class-switched CD27+IgD− B cells (21.2 vs. 5.0 × 103 cells/mL, respectively; p < 0.0001), and immunoglobulin G4 (40.9 vs. 19.4 mg/dL, respectively; p < 0.0001). Overall mortality was significantly associated with an elevated proportion of CD21low B cells (13.4 vs. 8.8%, respectively; p = 0.039) and CD56+ NK cells (238.8 vs. 314.1 × 103 cells/mL, respectively; p = 0.019). In multivariate analysis, better OS was significantly associated with lower numbers of CD56+ NK cells [hazard ratio (HR) 0.98, p = 0.041] and higher numbers of CD27+ memory B cells [(HR) 1.62, p = 0.014].Conclusion: Our data shows that autoantibody profiles are not suitable biomarkers for diagnosing cGvHD in children or for predicting cGvHD severity, disease course and outcome. We identified a number of indicators of aberrant immune homeostasis associated with active cGvHD in paediatric ALL patients after HSCT. These findings confirm published results and suggest that candidate B cell subpopulations may serve as a surrogate measure for characterisation of cGvHD in paediatric HSCT for malignant diseases, and warrants confirmation in larger, multicentre studies.

Impaired Innate Immunity in Pediatric Patients Type 1 Diabetes—Focus on Toll-like Receptors Expression

Type 1 diabetes (DM1) is classified as an autoimmune disease. An uncontrolled response of B and T lymphocytes to the body’s own tissues develops in the absence of immune tolerance. The main aim of the study was to evaluate the effect of the duration of type 1 diabetes in children on the expression of TLR receptors and the relationship with the parameters of glycemic control in patients. As a result, we showed significant differences in the level of TLR2, TLR4 and TLR9 expression in patients with DM1 in the early stage of the disease and treated chronically compared to the healthy group. Additionally, in this study, we found that the numbers of CD19+ B cells, CD3+ CD4+, CD3+ CD8+ T cells and NK cells are different for newly diagnosed DM1 individuals, patients receiving chronic treatment and for healthy controls, indicating an important role of these cells in killing pancreatic beta cells. Moreover, higher levels of IL-10 in patients with newly diagnosed DM1 have also been found, confirming the reports found in the literature.

CT-387: Prognostic Role of Lymphocyte to Monocyte Ratio in Pts Treated with CAR-T for Aggressive Lymphoma

Background Low absolute lymphocyte to monocyte ratio (ALC/AMC) predicts decreased survival in aggressive lymphoma (NHL) patients (pts) receiving chemotherapy and ASCT. We report the clinical significance of ALC/AMC and associated cellular phenotype changes in pts receiving chimeric antigen receptor T-cell (CAR-T) therapy. Methods We conducted a retrospective chart review of all pts who received axicabtagene ciloleucel for NHL at Mayo Clinic, Rochester, between 6/2016 and 12/2020. ALC and AMC were obtained from a clinical lab before lymphodepletion chemotherapy (LD). The receiver operator characteristic curve was generated using nominal logistic regression on ALC/AMC to predict complete remission (CR). Survivals were calculated using the Kaplan–Meier method. Blood immune phenotypes were assayed by multiparametric flow cytometry. Results Low ALC/AMC (≤0.8, n=29) prior to LD was associated with a lower CR rate (AUC=0.68, p=0.0004). Baseline characteristics were similar between the low and high ALC/AMC groups (>0.8, n=52), except for the use of prior ASCT and bridging therapy. The low ALC/AMC group also had higher CRP on the day of CAR-T infusion and was associated with shorter EFS and OS (EFS: 2.6 vs 6.4 months, p≤0.0001; OS: 5.3 months vs not reached, p=0.0006). Prognostic association remained statistically significant on multivariate analysis, which included prior ASCT, bridging therapy, and CRP. Compared to the high ALC/AMC group, the low ALC/AMC group had decreased CD4 Tem and increased CD16+CCR2+ monocytes (n=26). In addition, when comparing patients who achieved CR initially and relapsed versus those who maintained durable CR for 6 months or longer, there was a difference in these phenotypes, as well as the number of CD27+CD45RA+CD62L+ CD8 T cells and PD-1+TIGIT+ T cells. Conclusion ALC/AMC is a clinically accessible test that is strongly associated with CAR-T response and survival. Immune characterization revealed that the biological effect is not just associated with cell numbers. Phenotypes, such as monocytes with inflammatory capacity and T-cell subsets, may further distinguish between primary refractory disease, early relapse, and durable response. These data could inform future therapeutic strategies to improve clinical outcomes with CAR-T. This study was supported in part by the Mayo Clinic Center for Individualized Medicine and Henry J. Predolin Foundation.

Diagnostic and therapeutic challenge of unclassifiable enteropathies with increased intraepithelial CD103+ CD8+ T lymphocytes: a single center case series

Objectives Chronic diarrhea, villous atrophy and/or increased intraepithelial T-lymphocytes (IEL) occur in many inflammatory disorders including celiac disease (CD). However, a definite diagnosis is difficult to make in some patients despite an extensive diagnostic work-up. Clinical outcomes and histological phenotypes of such patients we refer to as unclassifiable enteropathy (UEP) remain unclear. Material and methods We performed a retrospective single-center analysis of patients with chronic diarrhea, weight loss and increased IEL. Patients with defined etiologies including infections, CD, drugs, immunodeficiencies or neoplasms were excluded. Clinical and histologic/immunophenotypic parameters were analyzed. Results Nine patients with UEP were identified. Small intestinal damage ranged from minor villous abnormalities to complete atrophy while all patients displayed high numbers of CD103+ CD8+ IELs. In contrast to CD, these CD8+ T cells were not confined to the surface epithelium, but also infiltrated the crypts. Additional histological features included apoptotic crypt epithelial cells and mixed inflammatory infiltrates in the tunica propria. Involvement of other segments of the gastrointestinal tract was observed in 7/9 patients. A clonal intestinal T-cell lymphoproliferative disorder developed in 2 patients, one of which had a fatal disease course. The majority of patients responded to corticosteroids, while response to immunosuppressive medications yielded heterogeneous results. Conclusions We report a patient population with ‘difficult-to-classify’ enteropathies characterized by various degrees of villous atrophy and strongly increased intraepithelial CD103+ CD8+ T cells in the small intestine which harbor an increased risk for T-cell lymphoproliferative disorders. Clinical course, histology, and response to immunosuppressive therapy all suggest an autoimmune pathogenesis.

Roles for STAT5 in homeostasis and function of CD103+cDC1s in non-lymphoid organs

Abstract Type 1 conventional dendritic cells (cDC1s) have critical roles in inducing adaptive immune responses and mediating immune tolerance. Signal Transducer and Activator of Transcription 5 (STAT5) was found to be crucial for monocyte-derived DC development; however, its role in non-lymphoid tissue CD103+cDC1s remained largely unknown. We evaluated the role of STAT5 by employing myeloid-specific Stat5-deficient mice,LysM-Cre +Stat5f/f and CD11c-Cre+Stat5f/f mice. Both strains show deficiencies in the numbers of CD103+cDC1s and alveolar macrophages (AMs) in lung, suggesting ineffective maintenance of lung homeostasis. Consistent with this concept, CD11c-Cre+Stat5f/f mice show granulocyte and monocyte accumulation in lung, accompanied by a reduction in the number of CD4+T, CD8+T, and B cells. Moreover, CD11c-Cre+Stat5-deficient mice have increased numbers of alveolar histiocytes, which are also enlarged, as well as accumulation of amorphous and eosinophilic material in alveolar spaces, alveolar histiocytosis, and proteinosis. In addition to the lung, liver CD103+cDC1s were also decreased by Stat5 depletion, however colon CD103+cDC1s were not affected. To examine cell-autonomous roles for STAT5, we generated Stat5-deficient CD103+cDC1s using our established bone marrow culture system, and tested in vitro-differentiated CD103+cDC1s for antigen presentation activity. These assays suggest Stat5 deficiency impaired CD103+cDC1s antigen cross-presentation ability. Taken together, our study showed that STAT5 is required for homeostasis and function of CD103+cDC1s in non-lymphoid organs.