The spatial landscape of T cells in the microenvironment of stage III lung adenocarcinoma.

This study aimed to provide more information for prognostic stratification for patients through an analysis of the T-cell spatial landscape. It involved analyzing stained tissue sections of 80 patients with stage III lung adenocarcinoma (LUAD) using multiplex immunofluorescence and exploring the spatial landscape of T cells and their relationship with prognosis in the center of the tumor (CT) and invasive margin (IM). In this study, multivariate regression suggested that the relative clustering of CT CD4+ conventional T cell (Tconv) to inducible Treg (iTreg), natural regulatory T cell (nTreg) to Tconv, terminal CD8+ T cell (tCD8) to helper T cell (Th), and IM Treg to tCD8 and the relative dispersion of CT nTreg to iTreg, IM nTreg to nTreg were independent risk factors for DFS. Finally, we constructed a spatial immunological score named the GT score, which had stronger prognostic correlation than IMMUNOSCORE® based on CD3/CD8 cell densities. The spatial layout of T cells in the tumor microenvironment and the proposed GT score can reflect the prognosis of patients with stage III LUAD more effectively than T-cell density. The exploration of the T-cell spatial landscape may suggest potential cell-cell interactions and therapeutic targets and better guide clinical decision-making. © 2024 The Pathological Society of Great Britain and Ireland.

Liver injury and prolonged hospitalization as indicators of severity in patients with adenovirus infections.

BACKGROUND: Adenovirus (ADV) is a prevalent infective virus in children, accounting for around 5-10% of all cases of acute respiratory illnesses and 4-15% of pneumonia cases in children younger than five years old. Without treatment, severe ADV pneumonia could result in fatality rates of over 50% in cases of emerging strains or disseminated disease. This study aims to uncover the relationship of clinical indicators with primary ADV infection severity, regarding duration of hospitalization and liver injury. METHODS: In this retrospective study, we collected and analyzed the medical records of 1151 in-patients who met the inclusion and exclusion criteria. According to duration of hospitalization, all patients were divided into three groups. Then the difference and correlation of clinical indicators with ADV infection were analyzed, and the relationship among liver injury, immune cells and cytokines was evaluated. RESULTS: The study revealed that patients with a duration of hospitalization exceeding 14 days had the highest percentage of abnormalities across most indicators. This was in contrast to the patients with a hospitalization duration of either less than or equal to 7 days or between 7 and 14 days. Furthermore, correlation analysis indicated that a longer duration of body temperature of ≥ 39°C, bilateral lung lobes infiltration detected by X ray, abnormal levels of AST, PaO2, and SPO2, and a lower age were all predictive of longer hospital stays. Furthermore, an elevated AST level and reduced liver synthesis capacity were related with a longer hospital stay and higher ADV copy number. Additionally, AST/ALT was correlated positively with IFN-γ level and IFN-γ level was only correlated positively with CD4+ T cells. CONCLUSIONS: The study provided a set of predicting indicators for longer duration of hospitalization, which responded for primary severe ADV infection, and elucidated the possible reason for prolonged duration of hospitalization attributing to liver injury via higher ADV copy number, IFN-γ and CD4+ T cells, which suggested the importance of IFN-γ level and liver function monitoring for the patients with primary severe ADV infection.

High Tumor-Infiltrating Lymphocyte Count Is Associated with Distinct Gene Expression Profile and Longer Patient Survival in Advanced Ovarian Cancer.

Cancer-related immunity plays a significant role in the outcome of ovarian cancer, but the exact mechanisms are not fully explored. A retrospective, real-life observational study was conducted including 57 advanced ovarian cancer patients. Immunohistochemistry for CD4+, CD8+, and CD45+ was used for assessing tumor-infiltrating immune cells. Furthermore, an immune-related gene expression assay was performed on 12-10 samples from patients with less than and more than 1-year overall survival (OS), respectively. A higher number of CD4+ (p = 0.0028) and CD45+ (p = 0.0221) immune cells within the tumor microenvironment were associated with longer OS of patients. In a multivariate setting, higher CD4+ T cell infiltration predicted longer OS (p = 0.0392). Twenty-three differentially expressed genes-involved in antigen presentation, costimulatory signaling, matrix remodeling, metastasis formation, and myeloid cell activity-were found when comparing the prognostic groups. It was found that tumor-infiltrating immune cell counts are associated with peculiar gene expression patterns and bear prognostic information in ovarian cancer. SOX11 expression emerged and was validated as a predictive marker for OS.

Update: Innate Lymphoid Cells in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic and nonspecific intestinal inflammatory condition with high relapse rate. Its pathogenesis has been linked to dysbacteriosis, genetic and environmental factors. In recent years, a new type of lymphocytes, termed innate lymphoid cells, has been described and classified into three subtypes of innate lymphoid cells-group 1, group 2 and group 3. An imbalance among these subsets' interaction with gut microbiome, and other immune cells affects intestinal mucosal homeostasis. Understanding the role of innate lymphoid cells may provide ideas for developing novel and targeted approaches for treatment of IBD.

Telomerase deficiency reflects age-associated changes in CD4+ T cells.

BACKGROUND: Amongst other systemic changes, aging leads to an immune dysfunction. On the molecular level, a hallmark of aging is telomere shortening. The functional relevance of telomerase, an enzyme capable of elongating telomeres in T cells upon antigen stimulation, is not fully understood. Studying the impact of telomere shortening on CD4+ T cells and especially Th1 effector function can provide a better understanding on immune dysfunctions in elderly. RESULTS: We investigated T cell numbers and differentiation in telomerase-deficient (mTerc-/-) mice under steady-state conditions and the functional role of telomerase in CD4+ T cells using in vitro stimulation and Th1 polarization protocols by comparing T cells from mTerc-/- and control mice. We report reduced relative CD4+ T cell numbers in blood and secondary lymphoid organs and a relative decline in the naïve T cell population in thymus, blood and spleen of mTerc-/- mice compared to control mice. Importantly, after in vitro polarization, mTerc-/- G3 CD4+ T cells showed higher numbers of IFNγ-producing cells and reduced expression of CD28. Notably, telomerase-deficient T cells were more susceptible to inhibition of Th1 polarization by IL-6 in vitro. These results demonstrate that telomerase deficiency recapitulates several changes of CD4+ T cells seen in aged humans regarding the naïve T cell population, expression of CD28 and cytokine production. CONCLUSION: Our data suggest that telomere shortening could play a key role in the aging of T cell immunity, with clinical implications for immune diseases and tumor development and that mTerc-/- mice are a suitable model to study aging-related defects of adaptive immunity.

[Immune system and allergies-An unholy alliance]. / Immunsystem und Allergien ­ eine unheilige Allianz.

Various factors affect the maturation of the infantile immune system both prenatally and postnatally, including risk and protective factors from the environment, nutrition, genetics and epigenetics. The microbiome seems to play a substantial role. The complex interaction and regulation of all these factors is ultimately decisive for whether a child develops an allergy during the course of development of the immune system. The genetic components play a decisive role in the development of allergic diseases. The epigenetic regulation could represent a mechanism where environmental influences act upon the immune regulation in the emergence of allergic diseases. The main factors in the pathophysiology of allergic reactions are a dysregulation of various cells of the innate and acquired immune systems as well as their interaction. This review describes the role of various T helper cell types in allergic diseases. The incidence and duration of airway infections are clearly increased in allergic patients compared to nonallergic controls. In addition to functional aspects, the reason for the more frequent infections is an impairment of the immune defence by the allergy-related persisting inflammation of the mucous membranes. These mechanisms must be differentiated from a true immunodeficiency. Allergic rhinitis (AR) and bronchial asthma are nowadays no longer defined as separate diseases but as two forms of expression of an atopic entity with a similar pathology. Both diseases can be mediated by immunoglobulin E and be elicited by identical triggers. A bronchial hyperreactivity is detectable in the majority of patients with AR but without clinical asthma.

CD4+ T-Cell Endogenous Cystathionine γ Lyase-Hydrogen Sulfide Attenuates Hypertension by Sulfhydrating Liver Kinase B1 to Promote T Regulatory Cell Differentiation and Proliferation.

BACKGROUND: Hydrogen sulfide (H2S) has antihypertension and anti-inflammatory effects, and its endogenous-generation key enzyme cystathionine γ lyase (CSE) is expressed in CD4+ T cells. However, the role of CD4+ T-cell endogenous CSE/H2S in the development of hypertension is unclear. METHODS: Peripheral blood lymphocytes were isolated from hypertensive patients or spontaneously hypertensive rats, then H2S production and expression of its generation enzymes, cystathionine ß synthase and CSE, were measured to determine the major H2S generation system changes in hypertension. Mice with CSE-specific knockout in T cells (conditional knockout, by CD4cre mice hybridization) and CD4 null mice were generated for investigating the pathophysiological relevance of the CSE/H2S system. RESULTS: In lymphocytes, H2S from CSE, but not cystathionine ß synthase, responded to blood pressure changes, supported by lymphocyte CSE protein changes and a negative correlation between H2S production with systolic blood pressure and diastolic blood pressure, but positive correlation with the serum level of interleukin 10 (an anti-inflammatory cytokine). Deletion of CSE in T cells elevated BP (5-8 mm Hg) under the physiological condition and exacerbated angiotensin II-induced hypertension. In keeping with hypertension, mesenteric artery dilation impaired association with arterial inflammation, an effect attributed to reduced immunoinhibitory T regulatory cell (Treg) numbers in the blood and kidney, thus causing excess CD4+ and CD8+ T cell infiltration in perivascular adipose tissues and kidney. CSE knockout CD4+ T cell transfer into CD4 null mice, also showed the similar phenotypes' confirming the role of endogenous CSE/H2S action. Adoptive transfer of Tregs (to conditional knockout mice) reversed hypertension, vascular relaxation impairment, and immunocyte infiltration, which confirmed that conditional knockout-induced hypertension was attributable, in part, to the reduced Treg numbers. Mechanistically, endogenous CSE/H2S promoted Treg differentiation and proliferation by activating AMP-activated protein kinase. In part, it depended on activation of its upstream kinase, liver kinase B1, by sulfhydration to facilitate its substrate binding and phosphorylation. CONCLUSION: The constitutive sulfhydration of liver kinase B1 by CSE-derived H2S activates its target kinase, AMP-activated protein kinase, and promotes Treg differentiation and proliferation, which attenuates the vascular and renal immune-inflammation, thereby preventing hypertension.

CD4+ T cells promote delayed B cell responses in the ischemic brain after experimental stroke.

CD4+ T lymphocytes are key mediators of tissue damage after ischemic stroke. However, their infiltration kinetics and interactions with other immune cells in the delayed phase of ischemia remain elusive. We hypothesized that CD4+ T cells facilitate delayed autoreactive B cell responses in the brain, which have been previously linked to post-stroke cognitive impairment (PSCI). Therefore, we treated myelin oligodendrocyte glycoprotein T cell receptor transgenic 2D2 mice of both sexes with anti-CD4 antibody following 60-minute middle cerebral artery occlusion and assessed lymphocyte infiltration for up to 72 days. Anti-CD4-treatment eliminated CD4+ T cells from the circulation and ischemic brain for 28 days and inhibited B cell infiltration into the brain, particularly in animals with large infarcts. Absence of CD4+ T cells did not influence infarct maturation or survival. Once the CD4+ population recovered in the periphery, both CD4+ T and B lymphocytes entered the infarct site forming follicle-like structures. Additionally, we provide further evidence for PSCI that could be attenuated by CD4 depletion. Our findings demonstrate that CD4+ T cells are essential in delayed B cell infiltration into the ischemic brain after stroke. Importantly, lymphocyte infiltration after stroke is a long-lasting process. As CD4 depletion improved cognitive functions in an experimental set-up, these findings set the stage to elaborate more specific immune modulating therapies in treating PSCI.

HIV Disease Progression: Overexpression of the Ectoenzyme CD38 as a Contributory Factor?

Despite abundant evidence associating CD38 overexpression and CD4 T cell depletion in HIV infection, no causal relation has been investigated. To address this issue, a series of mechanisms are proposed, supported by evidence from different fields, by which CD38 overexpression can facilitate CD4 T cell depletion in HIV infection. According to this model, increased catalytic activity of CD38 may reduce CD4 T cells' cytoplasmic nicotin-amide adenine dinucleotide (NAD), leading to a chronic Warburg effect. This will reduce mitochondrial function. Simultaneously, CD38's catalytic products ADPR and cADPR may be transported to the cytoplasm, where they can activate calcium channels and increase cytoplasmic Ca2+ concentrations, further altering mitochondrial integrity. These mechanisms will decrease the viability and regenerative capacity of CD4 T cells. These hypotheses can be tested experimentally, and might reveal novel therapeutic targets. Also see the video abstract here https://youtu.be/k1LTyiTKPKs.

Pleiotropic effects of vitamin D3 on CD4+ T lymphocytes mediated by human periodontal ligament cells and inflammatory environment.

AIMS: Both, vitamin D3 and human periodontal ligament cells (hPDLCs) possess immunosuppressive properties, but their combined effect on immune cells has never been investigated. Here, we analysed the impact of vitamin D3 on the immunosuppressive properties of hPDLCs towards CD4+ T lymphocytes. MATERIAL AND METHODS: Allogenic CD4+ T lymphocytes were activated by phytohemagglutinin either in monoculture or co-culture with hPDLCs, in the presence or absence of IFN-γ and 1,25(OH)2 D3 . After 5 days, CD4+ T-lymphocyte proliferation, CD4+ CD25+ FoxP3+ regulatory T lymphocytes (Tregs ) proportion and IL-10, TGF-ß1 and IL-17A production were analysed. RESULTS: In monoculture, 1,25(OH)2 D3 suppressed CD4+ T-lymphocyte proliferation, increased the percentage of CD4+ FoxP3+ CD25+ FoxP3+ Tregs and enhanced IL-10 and TGF-ß1 production. In the presence of IFN-γ treated hPDLCs, 1,25(OH)2 D3 significantly increased CD4+ T-lymphocyte proliferation and decreased the percentage of CD4+ CD25+ FoxP3+ Tregs . IL-10 and IL-17A expression was significantly diminished by 1,25(OH)2 D3 , whereas TGF-ß1 was slightly increased. The effects of 1,25(OH)2 D3 in co-culture were reversed by inhibition of indoleamine-2,3-dioxygenase-1, prostaglandin-endoperoxide synthase and programmed cell death 1 ligand 1. 1,25(OH)2 D3 also suppressed the expression of these proteins in hPDLCs. CONCLUSION: Effects of vitamin D3 on CD4+ T lymphocyte are modified by hPDLCs depending on the microenvironment.

Gardenia jasminoides extract and its constituent, genipin, inhibit activation of CD3/CD28 co-stimulated CD4+ T cells via ORAI1 channel.

Gardenia jasminoides (GJ) is a widely used herbal medicine with antiinflammatory properties, but its effects on the ORAI1 channel, which is important in generating intracellular calcium signaling for T cell activation, remain unknown. In this study, we investigated whether 70% ethanolic GJ extract (GJEtOH) and its subsequent fractions inhibit ORAI1 and determined which constituents contributed to this effect. Whole-cell patch clamp analysis revealed that GJEtOH (64.7% ± 3.83% inhibition at 0.1 mg/ml) and all its fractions showed inhibitory effects on the ORAI1 channel. Among the GJ fractions, the hexane fraction (GJHEX, 66.8% ± 9.95% at 0.1 mg/ml) had the most potent inhibitory effects in hORAI1-hSTIM1 co-transfected HEK293T cells. Chemical constituent analysis revealed that the strong ORAI1 inhibitory effect of GJHEX was due to linoleic acid, and in other fractions, we found that genipin inhibited ORAI1. Genipin significantly inhibited IORAI1 and interleukin-2 production in CD3/ CD28-stimulated Jurkat T lymphocytes by 35.9% ± 3.02% and 54.7% ± 1.32% at 30 µM, respectively. Furthermore, the same genipin concentration inhibited the proliferation of human primary CD4+ T lymphocytes stimulated with CD3/CD28 antibodies by 54.9% ± 8.22%, as evaluated by carboxyfluorescein succinimidyl ester assay. Our findings suggest that genipin may be one of the active components of GJ responsible for T cell suppression, which is partially mediated by activation of the ORAI1 channel. This study helps us understand the mechanisms of GJ in the treatment of inflammatory diseases.

Seminal plasma and CD4+ T-cell cytokine profiles in the in vitro fertilization success.

BACKGROUND: Abnormal female immune response is one of the potential causes of unexplained infertility (UI). Seminal plasma (SP) is an important regulator of female immune responses during pregnancy. This study investigated a SP effect on the expression of CD4+ T-cell-related cytokines in a group of UI woman candidates for in vitro fertilization (IVF) and healthy fertile women. MATERIALS AND METHODS: This was a semi-experimental study that performed on 20 UI couples (ten unsuccessful and ten successful IVF outcomes) and 10 fertile couples as the healthy group. CD4+ T-cells were separated from peripheral blood mononuclear cells of women by magnetic-activated cell sorting technique and incubated with (stimulated condition) or without (unstimulated condition) SP of their husbands. After incubation, real-time polymerase chain reaction method was used to investigate interleukin (IL)-23, IL-17, IL-4, IL-10, transforming growth factor (TGF)-ß, and interferon (IFN)-γ gene expression. Mann-Whitney U-test, Kruskal-Wallis test, and Wilcoxon signed-rank test were used for statistical analysis. RESULTS: Baseline TCD4+ mRNA levels of IL-23 (P = 0.03) and TGF-ß (P = 0.01) were different between healthy and infertile groups. However, IL-17, IL-4, IFN-γ, and IL-10 were expressed similarly regardless of fertility status. Comparing mRNA expression before and after SP exposure, our results have shown that relative expression of IL-23 significantly increased in successful (P = 0.04) and unsuccessful IVF groups (P = 0.01), whereas IL-10 expression increased only in the IVF failure group (P = 0.01). CONCLUSION: SP can make a positive effect on IVF outcome through alteration in CD4 + T-cell-related cytokines expression, especially IL-10 and IL-23.

[The expressions of CTLA-4 and PD-1 on CD(4)(+) T cells and the level of plasma VEGF in patients with obstructive sleep apnea hypopnea syndrome].

Objective: CD(4)(+)T cells, cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death-1 (PD-1) and vascular endothelial growth factor (VEGF) are associated with cancer development. The aim of the present study was to investigate the expression of CTLA-4, PD-1 and VEGF in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: From January 2017 to January 2018, a total of 47 first-visit outpatients were recruited in the Sleep and Respiratory Disorder Center of Guangdong Provincial People's Hospital, and were divided into control group (N=17, mean age 54±12 years), mild-to-moderate OSAHS group (N=15, mean age 54±12 years) and severe OSAHS group (N=15, mean age 56±13 years). Venous blood was collected, plasma and cells were isolated, the expressions of PD-1 and CTLA-4 on the surface of CD(4)(+)T cells were detected by flow cytometry, and plasma VEGF was measured by enzyme linked immunosorbent assay. Results: The proportion of CD(4)(+)T cells in control group, mild-to-moderate OSAHS group and severe OSAHS group were respectively(38±8)%, (35±8)% and (38±6)% (F=1.228, P>0.05). The expression of CTLA-4 on CD(4)(+)T cells were respectively [1.13 (0.59~1.78)]%, [0.45 (0.16~1.43)]% and [0.87(0.47~1.46)]% (H=2.205, P>0.05). The expression of PD-1 on CD(4)(+)T cells were respectively [4.24 (2.12~6.03)]%, [3.54(2.69~5.09)]% and [3.31(1.67~8.25)]% (H=0.541, P>0.05). The concentrations of VEGF in control group, mild-to-moderate OSAHS group and severe OSAHS group were statistically different [(395.16±87.78) ng/L vs (452.85±107.97) ng/L vs (546.42±199.27) ng/L, F=4.827, P=0.013]. Compared with the control group, VEGF concentration was significantly increased in the severe OSAHS group(P<0.01). VEGF concentration was correlated negatively with the lowest SpO(2) (r (s)=-0.480,P=0.001), but positively with apnea-hypopnea index(r (s)=0.403, P=0.005), oxygen desaturation index (r (s)=0.378, P=0.010) and proportion of SpO(2) less than or equal to 90% of total sleep time(r (s)=0.547, P=0.000 3). Conclusion: There was no significant difference of PD-1 and CTLA-4 expression on CD(4)(+)T cells in patients with and without OSAHS. The expression of VEGF was elevated in OSAHS patients, and increased with the severity of OSAHS and hypoxia.

[The clinical significance of CD(4)(+)CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia/Evans syndrome].

Objective: To investigate the significant of peripheral CD(4)(+) CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia (AIHA)/Evans syndrome (ES). Methods: In this study peripheral blood samples from 32 patients with AIHA/ES (15 hemolytic episode patients, 17 remission patients) and 13 healthy controls were collected. Patients with AIHA/ES were recruited in Tianjin Medical University General Hospital from October 2015 to May 2016. The percentages of CD(69)(+) T lymphocytes were analyzed by flow cytometry. The expression of CD(69) mRNA in CD(4)(+) T lymphocytes which was sorted from peripheral blood by magnetic activated cell sorting (MACS) was detected using real-time PCR. Soluable CD(69) was measured by ELISA. Results: In hemolytic episode patients, the ratio of CD(3)(+)CD(69)(+)/CD(3)(+)T lymphocytes [(3.08±1.48)%] was significantly higher than that in healthy controls [(1.28±0.83)%, P<0.01] and in remission group[(1.96±1.33)%, P<0.05]. The absolute count of CD(3)(+)CD(69)(+)T lymphocytes in hemolytic episode group [(2.94±1.81)×10(7)/L] was higher than that in healthy controls [(1.48±1.42)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T cells in hemolytic episode group [(2.16±1.56)%] was significantly higher than that in remission group [(1.16±0.62)%, P<0.05] and healthy controls[(0.94±0.78)%, P<0.05]. The quantity of CD(3)(+)CD(4)(+)CD(69)(+)T lymphocytes in hemolytic episode group[(1.04±0.98)×10(7)/L] was higher than in healthy controls [(0.44±0.38)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(8)(+)CD(69)(+)/CD(3)(+)CD(8)(+)T lymphocyte in hemolytic episode group [(4.87±2.56)%] was significantly higher than that in healthy controls[(1.83±1.27)%, P<0.01]. The quantity of CD(3)(+)CD(8)(+)CD(69)(+)T lymphocytes in three groups did not show significant difference. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+) T lymphocytes in hemolytic episode group was negatively correlated with hemoglobin (Hb) (P<0.01) , positively correlated with the percentage of reticulocytes (Ret%) (P=0.01) total bilirubin(TBil), indirect bilirubin(IBil) (P<0.01) and not correlated with absolute reticulocytes count, lactic dehydrogenase (LDH), complement 3(C3), complement 4 (C4). The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T lymphocytes in remission group was negatively correlated with Hb (P<0.05). In hemolytic episode patients CD(69) mRNA (32.26±35.11) was significantly higher than that in remission group(6.05±5.87) (P<0.05) and healthy controls (1.76±1.85)(P<0.01). CD(69) mRNA in remission group was significantly higher than healthy controls (P<0.05). Serum CD(69) in hemolytic episode patients [(494.21±16.06) ng/L] was significantly higher than that in healthy controls [(441.39±104.6) ng/L, P<0.05]. Conclusion: Our findings suggest that the proportion of CD(4)(+)CD(69)(+) T lymphocytes increase in AIHA/ES patients, which is correlated with the severity of disease.

Thymic NF-κB-inducing kinase regulates CD4+ T cell-elicited liver injury and fibrosis in mice.

BACKGROUND & AIMS: The liver is an immunologically-privileged organ. Breakdown of liver immune privilege has been reported in chronic liver disease; however, the role of adaptive immunity in liver injury is poorly defined. Nuclear factor-κB-inducing kinase (NIK) is known to regulate immune tissue development, but its role in maintaining liver homeostasis remains unknown. This study aimed to assess the role of NIK, particularly thymic NIK, in regulating liver adaptive immunity. METHODS: NIK was deleted systemically or conditionally using the Cre/loxp system. Cluster of differentiation [CD]4+ or CD8+ T cells were depleted using anti-CD4 or anti-CD8 antibody. Donor bone marrows or thymi were transferred into recipient mice. Immune cells were assessed by immunohistochemistry and flow cytometry. RESULTS: Global, but not liver-specific or hematopoietic lineage cell-specific, deletion of NIK induced fatal liver injury, inflammation, and fibrosis. Likewise, adoptive transfer of NIK-null, but not wild-type, thymi into immune-deficient mice induced liver inflammation, injury, and fibrosis in recipients. Liver inflammation was characterized by a massive expansion of T cells, particularly the CD4+ T cell subpopulation. Depletion of CD4+, but not CD8+, T cells fully protected against liver injury, inflammation, and fibrosis in NIK-null mice. NIK deficiency also resulted in inflammation in the lung, kidney, and pancreas, but to a lesser degree relative to the liver. CONCLUSIONS: Thymic NIK suppresses development of autoreactive T cells against liver antigens, and NIK deficiency in the thymus results in CD4+ T cell-orchestrated autoimmune hepatitis and liver fibrosis. Thus, thymic NIK is essential for the maintenance of liver immune privilege and liver homeostasis. LAY SUMMARY: We found that global or thymus-specific ablation of the NIK gene results in fatal autoimmune liver disease in mice. NIK-deficient mice develop liver inflammation, injury, and fibrosis. Our findings indicate that thymic NIK is essential for the maintenance of liver integrity and homeostasis.

Human mast cells costimulate T cells through a CD28-independent interaction.

Mast cells are innate immune cells usually residing in peripheral tissues, where they are likely to activate T-cell responses. Similar to other myeloid immune cells, mast cells can function as antigen-presenting cells. However, little is known about the capacity of human mast cells to costimulate CD4(+) T cells. Here, we studied the T-cell stimulatory potential of human mast cells. Peripheral blood derived mast cells were generated and cocultured with isolated CD4(+) T cells. In the presence of T-cell receptor triggering using anti-CD3, mast cells promoted strong proliferation of T cells, which was two- to fivefold stronger than the "T-cell promoting capacity" of monocytes. The interplay between mast cells and T cells was dependent on cell-cell contact, suggesting that costimulatory molecules on the mast cell surface are responsible for the effect. However, in contrast to monocytes, the T-cell costimulation by mast cells was independent of the classical costimulatory molecule CD28, or that of OX40L, ICOSL, or LIGHT. Our data show that mast cells can costimulate human CD4(+) T cells to induce strong T-cell proliferation, but that therapies aiming at disrupting the interaction of CD28 and B7 molecules do not inhibit mast cell mediated T-cell activation.

A transcriptome-based model of central memory CD4 T cell death in HIV infection.

BACKGROUND: Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state. METHODS: Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log2 Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses. RESULTS: Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1ß, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection. CONCLUSIONS: Our findings support a model where progressive loss of central memory CD4 T cells in chronic HIV-1 infection is driven by increased cell cycle entry followed by mitotic arrest, leading to a non-apoptotic death pathway without actual proliferation, possibly contributing to increased turnover.

Morbidity and nutrition status of rural drug-naïve Kenyan women living with HIV.

This paper describes morbidity in a group of HIV-positive drug-naïve rural women in western Kenya. A total of 226 drug-naïve HIV-positive women were evaluated for baseline morbidity, immune function, and anthropometry before a food-based nutrition intervention. Kenyan nurses visited women in their homes and conducted semi-structured interviews regarding symptoms and physical signs experienced at the time of the visit and during the previous week and physical inspection. Blood and urine samples were examined for determination of immune function (CD4, CD8, and total lymphocyte counts), anaemia, malaria, and pregnancy status. Intradermal skin testing with tuberculin (PPD), candida, and tetanus toxoid antigens was also performed to evaluate cell-mediated immunity. Anthropometry was measured, and body mass index (BMI) was calculated. Seventy-six per cent of the women reported being sick on the day of the interview or within the previous week. Illnesses considered serious were reported by 13.7% of women. The most frequent morbidity episodes reported were upper respiratory tract infections (13.3%), suspected malaria (5.85%), skeletal pain (4.87%), and stomach pain (4.42%). The most common morbidity signs on physical inspection were respiratory symptoms, most commonly rhinorrhea and coughing. Confirmed malaria and severe diarrhea were significantly associated with a higher BMI.

Exploring markers of immunoresponsiveness in papillary thyroid carcinoma and future treatment strategies.

BACKGROUND: The study summarizes the potential use of immunotherapy for BRAF-mutated papillary thyroid cancer (PTC) by analyzing the immune profile of City of Hope PTC patient samples and comparing them to the thyroid dataset available in the TCGA database. MATERIALS AND METHODS: PTC cases with available formalin-fixed paraffin-embedded archived tumor tissue were identified. RNA was extracted from the tumor tissue and analyzed by NanoString to evaluate their immune gene expression profile. Immunohistochemistry was used to determine the expression of immune suppressive genes and lymphocytic infiltration into the tumor tissue. Thyroid cancer cell lines (MDA-T32, MDA-T68, MDA-T85, and MDA-T120) were used to determine the correlation between the BRAF inhibition and CD274 expression. RESULTS: The study found that PTC cases with BRAF mutations had higher expression of immune checkpoint markers CD274 and CTLA4, as well as higher tumor-infiltrating lymphocytes, particularly CD4+T cells. Additionally, the study identified immunosuppressive markers expressed by tumor cells like CD73, CD276, and CD200 that could be targeted for immunotherapy. Further experiments using PTC cell lines lead to the conclusion that CD274 expression correlates with BRAF activity and that inhibitors of BRAF could potentially be used in combination with immunotherapy to treat PTC. CONCLUSIONS: These findings suggest that PTC cases with BRAF mutations or high expression may be correlated with an immune hot signature and could benefit from immunotherapeutic strategies.

mRNA vaccines against SARS-CoV-2 induce divergent antigen-specific T-cell responses in patients with lung cancer.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is highly transmissible and evades pre-established immunity. Messenger RNA (mRNA) vaccination against ancestral strain spike protein can induce intact T-cell immunity against the Omicron variant, but efficacy of booster vaccination in patients with late-stage lung cancer on immune-modulating agents including anti-programmed cell death protein 1(PD-1)/programmed death-ligand 1 (PD-L1) has not yet been elucidated. METHODS: We assessed T-cell responses using a modified activation-induced marker assay, coupled with high-dimension flow cytometry analyses. Peripheral blood mononuclear cells (PBMCs) were stimulated with various viral peptides and antigen-specific T-cell responses were evaluated using flow cytometry. RESULTS: Booster vaccines induced CD8+ T-cell response against the ancestral SARS-CoV-2 strain and Omicron variant in both non-cancer subjects and patients with lung cancer, but only a marginal induction was detected for CD4+ T cells. Importantly, antigen-specific T cells from patients with lung cancer showed distinct subpopulation dynamics with varying degrees of differentiation compared with non-cancer subjects, with evidence of dysfunction. Notably, female-biased T-cell responses were observed. CONCLUSION: We conclude that patients with lung cancer on immunotherapy show a substantial qualitative deviation from non-cancer subjects in their T-cell response to mRNA vaccines, highlighting the need for heightened protective measures for patients with cancer to minimize the risk of breakthrough infection with the Omicron and other future variants.