Reduced CCR6+IL-17A+Treg Cells in Blood and CCR6-Dependent Accumulation of IL-17A+Treg Cells in Lungs of Patients With Allergic Asthma.

Human regulatory T (Treg) cells play a central role in controlling allergic inflammation in the airways. A reduced number of peripheral Treg cells and decreased suppressive function have been previously reported in the pathogenesis of allergic asthma. However, the characteristic role of specific Treg cell subsets and their mechanisms in the pathogenesis of allergic asthma remain unclear. In this study, we examined the proportion of different Treg cell subsets in both healthy subjects and patients with allergic asthma using flow cytometry and single-cell RNA sequencing. The migration function of the cells was compared using cell sorting and Transwell experiments. Furthermore, two allergen-challenged mouse models and a cell transfer experiment were used to examine the role of these Treg subsets. We found that the proportion of CD25+Foxp3+CD127- Treg cells in the peripheral blood of patients with allergic asthma was lower than in those of healthy subjects. Furthermore, the circulating Treg cells expressed lower levels of CCR6 and IL-17 compared with healthy subjects. The chemokine from the airway mucosa, CCL20, was abundantly expressed, and Transwell experiments further proved that this chemokine promoted CCR6+ Treg cell migration in vitro. A mouse model induced by house dust mite (HDM) revealed that the number of CCR6+ Treg cells in the lung tissue increased remarkably. The incidence of allergic asthma may be related to an increase in Treg cells secreting IL-17 in the lung tissue. Recruited CCR6+ Treg cells are likely to differentiate into Th17-like cells under the Th17 environment present in the lungs. IL-17 derived from Th17-like cells could be associated with the pathology of allergic asthma by promoting Th17 responses, thereby favoring HDM-induced asthma exacerbations.

Age- and sex-dependent alterations in the peripheral immune system in the 3xTg-AD mouse model of Alzheimer's disease: Increased proportion of CD3+CD4-CD8- double-negative T cells in the blood.

It is well documented that sporadic Alzheimer's disease (AD) is a multifactorial disease and considered to be a result of several pathological events, both in the periphery and in the brain. The role of the peripheral immune system in the etiology and/or progression of the disease is not fully understood yet, and the results in humans are contradictory so far. Several animal models of AD have been generated and thoroughly characterized to elucidate disease mechanisms and evaluate numerous therapeutic strategies in preclinical studies. In the present study, we carried out a longitudinal evaluation of blood lymphocytes from male and female 3xTg-AD mice to document important immunological abnormalities in the periphery. We documented the age-dependent decrease in the percentage of CD3+ and CD4+ lymphocytes and an increase in the percentage CD3+CD4-CD8- (DN T) cells in the blood of 3xTg-AD mice compared with non-transgenic animals. Severe splenomegaly was observed in 3xTg-AD mice in contrast to wild-type animals. Importantly, all these abnormalities in the peripheral immune system appeared earlier and were more pronounced in males compared with females of the same age, which may account for the shorter lifespan of male mice. We suggest that future research should include the measurement of CD3+ and DN T cells as a potential immunological marker of disease progression in AD patients.

Lack of intrafollicular memory CD4 + T cells is predictive of early clinical failure in newly diagnosed follicular lymphoma.

Despite a characteristic indolent course, a substantial subset of follicular lymphoma (FL) patients has an early relapse with a poor outcome. Cells in the microenvironment may be a key contributor to treatment failure. We used a discovery and validation study design to identify microenvironmental determinants of early failure and then integrated these results into the FLIPI. In total, 496 newly diagnosed FL grade 1-3 A patients who were prospectively enrolled into the MER cohort from 2002 to 2012 were evaluated. Tissue microarrays were stained for CD4, CD8, FOXP3, CD32b, CD14, CD68, CD70, SIRP-α, TIM3, PD-1, and PD-L1. Early failure was defined as failing to achieve event-free survival at 24 months (EFS24) in immunochemotherapy-treated patients and EFS12 in all others. CyTOF and CODEX analysis were performed to characterize intratumoral immunophenotypes. Lack of intrafollicular CD4 expression was the only predictor of early failure that replicated with a pooled OR 2.37 (95%CI 1.48-3.79). We next developed a bio-clinical risk model (BioFLIPI), where lack of CD4 intrafollicular expression moved patients up one FLIPI risk group, adding a new fourth high-risk group. Compared with BioFLIPI score of 1, patients with a score of 2 (OR 2.17; 95% CI 1.08-4.69), 3 (OR 3.53; 95% CI 1.78-7.54), and 4 (OR 8.92; 95% CI 4.00-21.1) had increasing risk of early failure. The favorable intrafollicular CD4 T cells were identified as activated central memory T cells, whose prognostic value was independent from genetic features. In conclusion, lack of intrafollicular CD4 expression predicts early failure in FL and combined with FLIPI improves identification of high-risk patients; however, independent validation is warranted.

CMV exposure drives long-term CD57+ CD4 memory T-cell inflation following allogeneic stem cell transplant.

Donor and recipient cytomegalovirus (CMV) serostatus correlate with transplant-related mortality that is associated with reduced survival following allogeneic stem cell transplant (SCT). Prior epidemiologic studies have suggested that CMV seronegative recipients (R-) receiving a CMV-seropositive graft (D+) experience inferior outcomes compared with other serostatus combinations, an observation that appears independent of viral reactivation. We therefore investigated the hypothesis that prior donor CMV exposure irreversibly modifies immunologic function after SCT. We identified a CD4+/CD57+/CD27- T-cell subset that was differentially expressed between D+ and D- transplants and validated results with 120 patient samples. This T-cell subset represents an average of 2.9% (D-/R-), 18% (D-/R+), 12% (D+/R-), and 19.6% (D+/R+) (P < .0001) of the total CD4+ T-cell compartment and stably persists for at least several years post-SCT. Even in the absence of CMV reactivation post-SCT, D+/R- transplants displayed a significant enrichment of these cells compared with D-/R- transplants (P = .0078). These are effector memory cells (CCR7-/CD45RA+/-) that express T-bet, Eomesodermin, granzyme B, secrete Th1 cytokines, and are enriched in CMV-specific T cells. These cells are associated with decreased T-cell receptor diversity (P < .0001) and reduced proportions of major histocompatibility class (MHC) II expressing classical monocytes (P < .0001), myeloid (P = .024), and plasmacytoid dendritic cells (P = .0014). These data describe a highly expanded CD4+ T-cell population and putative mechanisms by which prior donor or recipient CMV exposure may create a lasting immunologic imprint following SCT, providing a rationale for using D- grafts for R- transplant recipients.

Histopathological and immunohistochemical features of facial papules in frontal fibrosing alopecia.

BACKGROUND: Facial papules (FPs) are considered to be created by the inflammatory process, which involves facial vellus hairs, in frontal fibrosing alopecia. AIM: To demonstrate the histopathological features of FPs and the composition of the inflammatory infiltrate. METHODS: In total, 18 patients with FPs were enrolled in the study after histopathological confirmation of lichen planopilaris. Histopathological evaluation of the specimens was performed by two dermatopathologists. The samples were immunostained with CD4, CD8 and CD123 monoclonal antibodies, and the percentage and proportion of cells stained with these markers were investigated. RESULTS: A follicular lichenoid reaction and perifollicular fibrosis were present in all cases. Vellus hairs were detected in 83.3% of biopsy specimens (15 cases), all of which were involved by the inflammation. The majority of the follicles (72%) revealed follicular plugs. Reduction and destruction of elastic fibres were visible in the perifollicular (adventitial) and the papillary dermis (100% and 78% of specimens, respectively). Prominent sebaceous glands and dilated ducts were detected in 78% and 72% of samples, respectively. CD4-positive T cells formed 67.72% and CD8-positive T cells 32.28% of the infiltrate, and the mean CD4/CD8 ratio was 2.48. In 13 (72.2%) biopsy specimens < 10% of the infiltrate was positive for CD123 marker. CONCLUSIONS: Perifollicular inflammation, fibrosis and elastic-fibre destruction were constant histopathological features of FPs; furthermore, prominent sebaceous glands were present in the majority of samples. We also observed a CD4-positive predominance in the infiltrate.

Host IL11 Signaling Suppresses CD4+ T cell-Mediated Antitumor Responses to Colon Cancer in Mice.

IL11 is a member of the IL6 family of cytokines and signals through its cognate receptor subunits, IL11RA and glycoprotein 130 (GP130), to elicit biological responses via the JAK/STAT signaling pathway. IL11 contributes to cancer progression by promoting the survival and proliferation of cancer cells, but the potential immunomodulatory properties of IL11 signaling during tumor development have thus far remained unexplored. Here, we have characterized a role for IL11 in regulating CD4+ T cell-mediated antitumor responses. Absence of IL11 signaling impaired tumor growth in a sporadic mouse model of colon cancer and syngeneic allograft models of colon cancer. Adoptive bone marrow transfer experiments and in vivo depletion studies demonstrated that the tumor-promoting activity of IL11 was mediated through its suppressive effect on host CD4+ T cells in the tumor microenvironment. Indeed, when compared with Il11ra-proficient CD4+ T cells associated with MC38 tumors, their Il11ra-deficient counterparts displayed elevated expression of mRNA encoding the antitumor mediators IFNγ and TNFα. Likewise, IL11 potently suppressed the production of proinflammatory cytokines (IFNγ, TNFα, IL6, and IL12p70) by CD4+ T cells in vitro, which we corroborated by RNAscope analysis of human colorectal cancers, where IL11RAhigh tumors showed less IFNG and CD4 expression than IL11RAlow tumors. Therefore, our results ascribe a tumor cell-extrinsic immunomodulatory role to IL11 during colon cancer development that could be amenable to an anticytokine-based therapy.See related Spotlight by van der Burg, p. 724.

The relation of CD3, CD4, CD8 and PD-1 expression with tumor type and prognosis in epithelial ovarian cancers.

OBJECTIVES: Ovarian cancer is a heterogeneous disease, where chronic inflammation plays a key role in carcinogenesis. In this study, it is aimed to analyze the relationship with prognosis and chemotherapy response to clinicopathologicalnvariables in epithelial ovarian cancers such as proliferation of PD-1 +, CD8 +, CD4 +, CD3 + T-lymphocytes infiltrating the tumor and tumor stroma. MATERIAL AND METHODS: Seventy-six cases diagnosed with primary epithelial ovarian tumor from biopsy or surgical resection materials were included in the study. Immunreactivity of CD3, CD4, CD8, PD1 was evaluated immunohistochemically in lymphocytes in tumor infiltrating lymphocytes and stromal lymphocytes. RESULTS: Seventeen (22.4%) of the cases were Type I, 59 (77.6%) of them were Type II ovarian carcinoma. PD-1 positivity was observed in stromal and intraepithelial lymphocytes in 22 (28.9%) of 76 cases. In the presence of PD-1 + T-lymphocytes that infiltrate tumor and stroma, disease-free survival are shorter (p = 0.037). The presence of stromal CD4 + and CD8 + T-lymphocytes was more common in late stage patients (p = 0.012, p = 0.036; respectively). The disease-free and overall survival rate was statistically significantly shorter in the presence of CD8 + T lymphocytes (p = 0.009, p = 0.003; respectively). CONCLUSIONS: CD3, CD4 and CD8 may contribute to PD-1 mediated tumor control. Anti PD-1 therapy may be an alternative to chemotherapy in PD-1 positive patients. Identifying patients who do not respond to chemotherapy through PD-1 expression prior to immunotherapy will help develop potential personalized immunotherapy.

Lost in Translation: Lack of CD4 Expression due to a Novel Genetic Defect.

CD4 expression identifies a subset of mature T cells primarily assisting the germinal center reaction and contributing to CD8+ T-cell and B-cell activation, functions, and longevity. Herein, we present a family in which a novel variant disrupting the translation-initiation codon of the CD4 gene resulted in complete loss of membrane and plasma soluble CD4 in peripheral blood, lymph node, bone marrow, skin, and ileum of a homozygous proband. This inherited CD4 knockout disease illustrates the clinical and immunological features of a complete deficiency of any functional component of CD4 and its similarities and differences with other clinical models of primary or acquired loss of CD4+ T cells. The first inherited loss of any functional component of CD4, including soluble CD4, is clinically distinct from any other congenital or acquired CD4 T-cell defect and characterized by compensatory changes in T-cell subsets and functional impairment of B cells, monocytes, and natural killer cells.

Preparation and characterization of monoclonal antibodies recognizing two CD4 isotypes of Microminipigs.

Cluster of differentiation 4 (CD4) molecule expressed on the leukocytes is known to function as a co-receptor for class II major histocompatibility complex (MHC) binding to T cell receptor (TCR) on helper T cells. We previously identified two CD4 alleles (CD4.A and CD4.B) in a Microminipig population based on nucleotide sequencing and PCR detection of their gene sequences. However, CD4.B protein expression was not examined because of the unavailability of a reactive antibody to a CD4.B epitope. In this study, we have produced two swine-specific monoclonal antibodies (mAbs) against CD4.B molecules, one that recognizes only CD4.B (b1D7) and the other that recognizes both the CD4.A and CD4.B alleles (x1E10) and that can be used to distinguish CD4 T cell subsets by flow cytometry and immunohistochemistry. Using these two mAbs, we identified CD4.A and CD4.B allele-specific proteins on the surface of CD4.A (+/+) and CD4.B (+/+) T cells at a similar level of expression. Moreover, stimulation of peripheral blood mononuclear cells (PBMCs) derived from CD4.A (+/+) and CD4.B (+/+) swine with toxic shock syndrome toxin-1 (TSST-1) in vitro similarly activated both groups of cells that exhibited a slight increase in the CD4/CD8 double positive (DP) cell ratio. A large portion of the DP cells from the allelic CD4.A (+/+) and CD4.B (+/+) groups enhanced the total CD4 and class I swine leukocyte antigen (SLA) expression. The x1E10 mAb delayed and reduced the TSST-1-induced activation of CD4 T cells. Thus, CD4.B appears to be a functional protein whose expression on activated T cells is analogous to CD4.A.

Immune status is prognostic for poor survival in colorectal cancer patients and is associated with tumour hypoxia.

BACKGROUND: Immunohistochemical quantification of the immune response is prognostic for colorectal cancer (CRC). Here, we evaluate the suitability of alternative immune classifiers on prognosis and assess whether they relate to biological features amenable to targeted therapy. METHODS: Overall survival by immune (CD3, CD4, CD8, CD20 and FOXP3) and immune-checkpoint (ICOS, IDO-1 and PD-L1) biomarkers in independent CRC cohorts was evaluated. Matched mutational and transcriptomic data were interrogated to identify associated biology. RESULTS: Determination of immune-cold tumours by combined low-density cell counts of CD3, CD4 and CD8 immunohistochemistry constituted the best prognosticator across stage II-IV CRC, particularly in patients with stage IV disease (HR 1.98 [95% CI: 1.47-2.67]). These immune-cold CRCs were associated with tumour hypoxia, confirmed using CAIX immunohistochemistry (P = 0.0009), which may mediate disease progression through common biology (KRAS mutations, CRIS-B subtype and SPP1 mRNA overexpression). CONCLUSIONS: Given the significantly poorer survival of immune-cold CRC patients, these data illustrate that assessment of CD4-expressing cells complements low CD3 and CD8 immunohistochemical quantification in the tumour bulk, potentially facilitating immunophenotyping of patient biopsies to predict prognosis. In addition, we found immune-cold CRCs to associate with a difficult-to-treat, poor prognosis hypoxia signature, indicating that these patients may benefit from hypoxia-targeting clinical trials.

CXCL4 promoted the production of CD4+CD25+FOXP3+treg cells in mouse sepsis model through regulating STAT5/FOXP3 pathway.

Background: CXCL4 plays an essential role in the regulation of multiple immune diseases. However, the underlying role of CXCL4 is still not clear in sepsis. Aim: In the present study, we aimed to investigate the function of CXCL4 in sepsis.Methods: Sepsis model was constructed on mouse. Flow cytometry was used to determine the ratio of CD4+CD25+FOXP3+Treg cells. ELISA assays were used to determine the levels of CXCL4, IL-6, IL-10, and TNF-α respectively. Western blot was used to examine protein contents.Results: Our results suggested that the serum level of CXCL4 was upregulated in patients with sepsis and positively associated with the ratio of human CD4+CD25+FOXP3+Treg cells. To further examine the role of CXCL4 in sepsis, we constructed the mouse sepsis model. Our results indicated that the mouse antibody of CXCL4 treatment reduced the expression of urine creatinine and urea nitrogen in sepsis model. Moreover, the frequency of CD25+FOXP3+ mouse regulatory T cells (Tregs) cells was decreased in mouse CD4+ T cells in the presence of mouse CXCL4 antibody. Further, the mouse recombinant protein CXCL4 was used to culture normal mouse CD4+ T cells in vitro. Our finding indicated that the recombinant protein CXCL4 promoted the percentage of mouse CD25+FOXP3+Treg cells and enhanced the phosphorylation of STAT5 in mouse CD4+ T cells in a dose-dependent manner. However, these effects were significantly reversed by the STAT5 inhibitor (p < .001). Conclusion: our findings not only indicated the function and signalling pathway of CXCL4 in CD4+ T cells but also provided novel insight and target in sepsis treatment.

Characterization of the immune profile of oral tongue squamous cell carcinomas with advancing disease.

We investigated whether a unique immune response was instigated with the development of oral tongue squamous cell carcinomas (OTSCC), with/without nodal involvement, with/without recurrent metastatic disease, or within tumor involved nodes. One hundred and ten formalin-fixed paraffin-embedded samples were collected from a retrospective cohort of 67 OTSCC patients and 10 non-cancerous tongue samples. Targets including CD4, CD8, FOXP3, PD-L1, and PD-1 were analyzed by immunohistochemistry. The Nanostring PanCancer Immune Profiling Panel was used for gene expression profiling. Data were externally validated in the The Cancer Genome Atlas (TCGA) head and neck (HNSCC), melanoma and lung squamous cell carcinoma (LSCC) cohorts. A 24-immune gene signature was identified that discriminated more aggressive OTSCC cases, and although not prognostic in HNSCC was associated with survival in other TCGA cohorts (improved survival for melanoma, P < .001 and worse survival for LSCC, P = .038). OTSCC exhibited concordant gene and immunohistochemical (IHC) features characterized by a TH-2 biased, proinflammatory profile with upregulated B cell and neutrophil gene activity and increased CD4, FOXP3, and PD-L1 expression (P < .001 for all by IHC). Compared to less advanced disease, nodal involvement and recurrent OTSCC did not induce a different immune response although recurrent disease was characterized by significantly higher PD-L1 expression (P = .004 by SP263, P = .013 by 22C3, P = .004 for gene expression). Identification of a gene signature associated with different prognostic effects in other cancers highlights common pathways of immune dysregulation that are impacted by the tumor origin. The significant immunosuppressive signaling in OTSCC indicates primary failure of immune system to control carcinogenesis emphasizing the need for early, combination therapeutic approaches.

TCR-α/ß CD4- CD8- double negative T cells arise from CD8+ T cells.

The cellular origin of CD4- CD8- (double negative, DNT) TCR-α/ß+ T cells remains unknown. Available evidence indicates that they may derive from CD8+ T cells, but most published data have been obtained using cells that bear an invariant transgenic T cell receptor that recognizes an Ag that is not present in normal mice. Here, we have used complementary fate mapping and adoptive transfer experiments to identify the cellular lineage of origin of DNT cells in wild-type mice with a polyclonal T cell repertoire. We show that TCR-α/ß+ DNT cells can be traced back to CD8+ and CD4+ CD8+ double positive cells in the thymus. We also demonstrate that polyclonal DNT cells generated in secondary lymphoid organs proliferate upon adoptive transfer and can regain CD8 expression in lymphopenic environment. These results demonstrate the cellular origin of DNT cells and provide a conceptual framework to understand their presence in pathological circumstances.

Autoantigen specific IL-2 activated CD4+CD25+T regulatory cells inhibit induction of experimental autoimmune neuritis.

Experimental autoimmune neuritis (EAN) induced by peripheral nerve myelin (PNM) is self-limiting and re-immunization with PNM does not re-activate disease. This study showed inhibition of EAN by CD4+CD25+T cells both from sensitized hosts or from naïve hosts after ex-vivo activation by PNM and rIL-2. Transfer of naïve CD4+CD25+T cells has no effect on EAN, nor did naïve CD4+CD25+T cells activated with rIL-2 and renal tubular antigen. Culture of naive CD4+CD25+Treg with rIL-2 and PNM induced mRNA for the IFN-gamma receptor. We showed naïve CD4+CD25+T cells activated by specific auto-antigen and rIL-2 produced more potent antigen-specific Treg that may have therapeutic potential.

Time to viral load suppression and its associated factors in cohort of patients taking antiretroviral treatment in East Shewa zone, Oromiya, Ethiopia, 2018.

BACKGROUND: A key goal of Antiretroviral Treatment (ART) is to achieve and maintain durable viral suppression. Thus, the most important use of viral load measurement is to monitor the effectiveness of therapy after initiation of ART. The main objective of the study was to determine the time for virological suppression and its associated factors among people living with HIV taking antiretroviral treatments in East Shewa Zone, Oromiya, Ethiopia. METHODS: Patients diagnosed with Human Immunodeficiency Virus presenting to the study health centers between October 3, 2011 and March 1, 2013 were included in the study given the following criteria: age 18 years or greater, eligible to start ART. All patients with baseline viral load measurements were included in the study. Interaction between explanatory variables with the response variable was analyzed by using cross tab features of (Statistical Package for the Social Sciences) SPSS, International Business Machines (IBM) Inc. Significance group comparison was done by Kaplan Meier log-rank test. Cox proportional hazard model was used to select significant factors to the variability between groups. RESULT: Plasma viral load was suppressed below the detection level in 72% of individuals taking a different regimen of ART. The median Human Immunodeficiency virus (HIV)-1 plasma viral load in the cohort was estimated to be log 5.3111 copies/ml. The study observed Survival curve difference in the category of marital status (p-value 0.023) and baseline cluster of differentiation 4 (CD4) value (p-value 0.023). The estimated median time to Plasma Viral Load (PVL) suppression was 181 days (CI: 140.5-221.4) with the age group of 30-39 years having minimum time to achieve suppression with 92 days (CI: 60.1-123.8) and the maximum time required to reach the level was found among the age group between 50 and 59 years. CONCLUSION: The study found that the estimated time to achieve PVL after taking ART to be 181 days. Factors affecting time to suppression level were marital status and baseline CD4.