Derivation of functional thymic epithelial organoid lines from adult murine thymus.

Thymic epithelial cells (TECs) orchestrate T cell development by imposing positive and negative selection on thymocytes. Current studies on TEC biology are hampered by the absence of long-term ex vivo culture platforms, while the cells driving TEC self-renewal remain to be identified. Here, we generate long-term (>2 years) expandable 3D TEC organoids from the adult mouse thymus. For further analysis, we generated single and double FoxN1-P2A-Clover, Aire-P2A-tdTomato, and Cldn4-P2A-tdTomato reporter lines by CRISPR knockin. Single-cell analyses of expanding clonal organoids reveal cells with bipotent stem/progenitor phenotypes. These clonal organoids can be induced to express Foxn1 and to generate functional cortical- and Aire-expressing medullary-like TECs upon RANK ligand + retinoic acid treatment. TEC organoids support T cell development from immature thymocytes in vitro as well as in vivo upon transplantation into athymic nude mice. This organoid-based platform allows in vitro study of TEC biology and offers a potential strategy for ex vivo T cell development.

Corrigendum: Regulatory T cells targeting a pathogenic MHC class II: insulin peptide epitope postpone spontaneous autoimmune diabetes.

[This corrects the article DOI: 10.3389/fimmu.2023.1207108.].

Cerebellar degeneration in gluten ataxia is linked to microglial activation.

Gluten sensitivity has long been recognized exclusively for its gastrointestinal involvement; however, more recent research provides evidence for the existence of neurological manifestations that can appear in combination with or independent of the small bowel manifestations. Amongst all neurological manifestations of gluten sensitivity, gluten ataxia is the most commonly occurring one, accounting for up to 40% of cases of idiopathic sporadic ataxia. However, despite its prevalence, its neuropathological basis is still poorly defined. Here, we provide a neuropathological characterization of gluten ataxia and compare the presence of neuroinflammatory markers glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, major histocompatibility complex II and cluster of differentiation 68 in the central nervous system of four gluten ataxia cases to five ataxia controls and seven neurologically healthy controls. Our results demonstrate that severe cerebellar atrophy, cluster of differentiation 20+ and cluster of differentiation 8+ lymphocytic infiltration in the cerebellar grey and white matter and a significant upregulation of microglial immune activation in the cerebellar granular layer, molecular layer and cerebellar white matter are features of gluten ataxia, providing evidence for the involvement of both cellular and humoral immune-mediated processes in gluten ataxia pathogenesis.

Novel Presentation of Major Histocompatibility Complex Class II Deficiency with Hemophagocytic Lymphohistiocytosis.

PURPOSE: Major histocompatibility complex (MHC) class II deficiency is one of the combined immune deficiency disorders caused by defects in the MHC class II regulatory genes leading to abnormal T cells development and function. Therefore, patients mainly present with increased susceptibility to infections, diarrhea, and failure to thrive. In this report, we present one MHC class II deficient patient with a novel presentation with Hemophagocytic Lymphohistiocytosis (HLH). METHODS: Immunophenotyping of lymphocyte subpopulations and HLA-DR expression was assess by flow cytometry. Gene mutational analysis was performed by whole exome and Sanger sequencing. RESULTS: We reported a 7-year-old girl, who was diagnosed at age of 2 years with MHC class II deficiency by genetic testing and flow cytometry. Two years later, she developed disseminated BCGitis which was treated with proper antimicrobial agents. At the age of 7 years, she presented with clinical features fulfilling 6 diagnostic criteria of HLH including evidence of hemophagocytic activity in bone marrow aspiration. Accordingly, the diagnosis of HLH was established and the patient was started on IV Dexamethasone, Anakinra and IVIG. Eventually, patient started to improve and was discharged in good condition. Few months later, the patient was readmitted with severe pneumonia and sepsis leading to death. CONCLUSION: Patients with MHC class II deficiency might present with disseminated BCGitis especially if the patient has severe T cell lymphopenia. Additionally, this immune defect might be added to the list of inborn errors of immunity that can be complicated with HLH.

Lung Interstitial Macrophages Can Present Soluble Antigens and Induce Foxp3+ Regulatory T Cells.

Lung macrophages constitute a sophisticated surveillance and defense system that contributes to tissue homeostasis, host defense, and allows the host to cope with the myriad of insults and antigens to which the lung mucosa is exposed. As opposed to alveolar macrophages, lung interstitial macrophages express high levels of type 2 major histocompatibility complex (MHC-II), a hallmark of antigen-presenting cells. Here, we showed that lung IMs, like dendritic cells (DCs), possess the machinery to present soluble antigens in an MHC-II-restricted way. Using ex vivo ovalbumin (OVA)-specific T cell proliferation assays, we found that OVA-pulsed IMs could trigger OVA-specific CD4+ T cell proliferation and Foxp3 expression via MHC-II-, IL-10 and Tgfß-dependent mechanisms. Moreover, we showed that IMs efficiently captured locally instilled antigens in vivo, did not migrate to the draining lymph nodes and enhanced local interactions with CD4+ T cells in a model of OVA-induced allergic asthma. These results support that IMs can present antigens to CD4+ T cells and trigger regulatory T cells, which might attenuate lung immune responses and have functional consequences for lung immunity and T-cell-mediated disorders.

MARCH-I: A negative regulator of dendritic cell maturation.

The expression of costimulatory molecules such as MHC-II, CD86 and CD83 on dendritic cells (DCs) are strongly regulated during cellular activation. Ubiquitination of some of these markers by the E3 ubiquitin ligase MARCH-I affects the maturation state of DCs and subsequently modulates immune responses. The effects of MARCH-I gene overexpression on the functional activity of human DCs is not well understood. Here, we investigate how MARCH-I, regulates maturation of DCs. We now provide evidence that MARCH-I transduced DCs secrete high levels of IL10 despite low secretion of IL 6 and IL 12 in response to LPS stimulation. They are weak stimulators of T lymphocyte cells but skewed T cell polarization toward T regulatory subset. These results exhibit that reduced expression of surface costimulatory molecules suppresses DC activation. It can be concluded that overexpression of MARCH-I gene in DCs leads to the production of tolerogenic DC.

Structure-aware deep model for MHC-II peptide binding affinity prediction.

The prediction of major histocompatibility complex (MHC)-peptide binding affinity is an important branch in immune bioinformatics, especially helpful in accelerating the design of disease vaccines and immunity therapy. Although deep learning-based solutions have yielded promising results on MHC-II molecules in recent years, these methods ignored structure knowledge from each peptide when employing the deep neural network models. Each peptide sequence has its specific combination order, so it is worth considering adding the structural information of the peptide sequence to the deep model training. In this work, we use positional encoding to represent the structural information of peptide sequences and validly combine the positional encoding with existing models by different strategies. Experiments on three datasets show that the introduction of position-coding information can further improve the performance built upon the existing model. The idea of introducing positional encoding to this field can provide important reference significance for the optimization of the deep network structure in the future.

NLRP3 regulates CIITA/MHC II axis and interferon-γ-inducible chemokines in Malassezia globosa-infected keratinocytes.

CIITA, a member of NOD-like receptor (NLR) family, is the major MHC II trans-activator and mediator of Th1 immunity, but its function and interaction with NLRP3 have been little studied. We found activation of NLRP3 inflammasome, increased expression of CIITA, CBP, pSTAT1, STAT1, MHC II, IFN-γ and IFN-γ-inducible chemokines (CCL1 and CXCL8), and colocalisation of NLRP3 with CIITA in Malassezia folliculitis lesions, Malassezia globosa-infected HaCaT cells and mouse skin. CoIP with anti-CIITA or anti-NLRP3 antibody pulled down NLRP3 or both CIITA and ASC. NLRP3 silencing or knockout caused CIITA downexpression and their colocalisation disappearance in HaCaT cells and mouse skin of Nlrp3-/- mice, while CIITA knockdown had no effect on NLRP3, ASC, IL-1ß and IL-18 expression. NLRP3 inflammasome inhibitors and knockdown significantly suppressed IFN-γ, CCL1, CXCL8 and CXCL10 levels in M. globosa-infected HaCaT cells. CCL1 and CXCL8 expression was elevated in Malassezia folliculitis lesions and reduced in Nlrp3-/- mice. These results demonstrate that M. globosa can activate NLRP3 inflammasome, CIITA/MHC II signalling and IFN-γ-inducible chemokines in human keratinocytes and mouse skin. NLRP3 may regulate CIITA by their binding and trigger Th1 immunity by secreting CCL1 and CXCL8/IL-8, contributing to the pathogenesis of Malassezia-associated skin diseases.

Anti-Inflammatory Effect of Technologically Processed Antibodies to the Molecules of the Major Histocompatibility Complex in a Model of Acute Inflammation In Vivo.

The anti-inflammatory effect of technologically processed antibodies (TPA) to immune targets (MHC I and MHC II) was assessed in the carrageenan-induced rat paw edema model. The parameters "increase in edema" and "suppression of edema" significantly decreased (p<0.05) against the background of treatment with TPA and the reference drug indomethacin compared to the placebo group. The tested TPA produced an anti-inflammatory effect.

MHC II-EGFP Knock-in Mouse Model.

The MHC II-EGFP knock-in mouse model enables us to visualize and track MHC-II-expressing cells in vivo by expressing enhanced green fluorescent protein (EGFP) fused to the MHC class II molecule under the MHC II beta chain promoter. Using this model, we can easily identify MHC-II-expressing cells, including dendritic cells, B cells, macrophages, and ILC3s, which play a key role as antigen-presenting cells (APCs) for CD4+ T cells. In addition, we can also precisely identify and analyze APC-containing tissues and organs. Even after fixation, EGFP retains its fluorescence, so this model is suitable for immunofluorescence studies, facilitating an unbiased characterization of the histological context, especially with techniques such as light-sheet fluorescence microscopy. Furthermore, the MHC II-EGFP knock-in mouse model is valuable for studying the molecular mechanisms of MHC II gene regulation and expression by making it possible to correlate MHC II expression (MHC II-EGFP) with surface fraction through antibody detection, thereby shedding light on the intricate regulation of MHC II expression. Overall, this model is an essential asset for quantitative and systems immunological research, providing insights into immune cell dynamics and localization, with a tool for precise cell identification and with the ability to study MHC II gene regulation, thus furthering the understanding of immune responses and underlying mechanisms © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Characterization of antigen-specific MHC II loading compartment tubulation toward the immunological synapse Basic Protocol 2: Characterization of overall versus surface MHC II expression Basic Protocol 3: Identification and preparation of the lymphoid organs Basic Protocol 4: Quantification of APC content in lymphoid organs by fluorescence stereomicroscopy Basic Protocol 5: Quantification and measurement of intestinal lymphoid tissue by light-sheet fluorescence stereomicroscopy Basic Protocol 6: Visualization of corneal APCs Basic Protocol 7: Quantification of MHC II+ cells in maternal milk by flow cytometry Support Protocol 1: Cell surface staining and flow cytometry analysis of spleen mononuclear cells.

The crosstalk between ILC3s and adaptive immunity in diseases.

RORγt+ group 3 innate lymphoid cells (ILC3s), the innate counterpart of Th17 cells, are enriched in the mucosal area and lymphoid tissues. ILC3s interact with a variety of cells through their effector molecules and play an important role in the host defense against a spectrum of infections. Recent studies suggest that the extensive crosstalk between ILC3s and adaptive immune cells, especially T cells, is essential for maintaining tissue homeostasis. Here we discuss recent advances in the crosstalk between ILC3s and adaptive immune responses in multiple tissues and diseases. Understanding how ILC3s engage with adaptive immune cells will enhance our comprehension of diseases and facilitate the identification of novel therapeutic targets.

Antiallergic Effects of Technologically Processed Antibodies to MHC II.

The risk of developing anaphylactic reactions to medications introduces additional difficulties for effective pharmacotherapy. Using a model of systemic anaphylaxis in mice, we showed that preventive administration of a preparation containing technologically processed antibodies (TPA) to MHC II induces an anti-anaphylactic effect comparable to that of dexamethasone (when assessing the severity of systemic anaphylaxis 30 and 60 min after challenge injection of the model antigen ovalbumin). The revealed activity may be related to the ability of TPA to MHC II to regulate the antigen presentation system and shift the immune response towards the production of IgG instead of IgE typical of anaphylactic reaction.

Profound N-glycan remodelling accompanies MHC-II immunopeptide presentation.

Immunopeptidomics, the study of peptide antigens presented on the cell surface by the major histocompatibility complex (MHC), offers insights into how our immune system recognises self/non-self in health and disease. We recently discovered that hyper-processed (remodelled) N-glycans are dominant features decorating viral spike immunopeptides presented via MHC-class II (MHC-II) molecules by dendritic cells pulsed with SARS-CoV-2 spike protein, but it remains unknown if endogenous immunopeptides also undergo N-glycan remodelling. Taking a multi-omics approach, we here interrogate published MHC-II immunopeptidomics datasets of cultured monocyte-like (THP-1) and breast cancer-derived (MDA-MB-231) cell lines for overlooked N-glycosylated peptide antigens, which we compare to their source proteins in the cellular glycoproteome using proteomics and N-glycomics data from matching cell lines. Hyper-processed chitobiose core and paucimannosidic N-glycans alongside under-processed oligomannosidic N-glycans were found to prevalently modify MHC-II-bound immunopeptides isolated from both THP-1 and MDA-MB-231, while complex/hybrid-type N-glycans were (near-)absent in the immunopeptidome as supported further by new N-glycomics data generated from isolated MHC-II-bound peptides derived from MDA-MB-231 cells. Contrastingly, the cellular proteomics and N-glycomics data from both cell lines revealed conventional N-glycosylation rich in complex/hybrid-type N-glycans, which, together with the identification of key lysosomal glycosidases, suggest that MHC-II peptide antigen processing is accompanied by extensive N-glycan trimming. N-glycan remodelling appeared particularly dramatic for cell surface-located glycoproteins while less remodelling was observed for lysosomal-resident glycoproteins. Collectively, our findings indicate that both under- and hyper-processed N-glycans are prevalent features of endogenous MHC-II immunopeptides, an observation that demands further investigation to enable a better molecular-level understanding of immune surveillance.

Development of a semi-automated MHC-associated peptide proteomics (MAPPs) method using streptavidin bead-based immunoaffinity capture and nano LC-MS/MS to support immunogenicity risk assessment in drug development.

Major histocompatibility complex (MHC)-Associated Peptide Proteomics (MAPPs) is an ex vivo method used to assess the immunogenicity risk of biotherapeutics. MAPPs can identify potential T-cell epitopes within the biotherapeutic molecule. Using adalimumab treated human monocyte derived dendritic cells (DCs) and a pan anti-HLA-DR antibody (Ab), we systematically automated and optimized biotin/streptavidin (SA)-capture antibody coupling, lysate incubation with capture antibody, as well as the washing and elution steps of a MAPPs method using functionalized magnetic beads and a KingFisher Magnetic Particle processor. Automation of these steps, combined with capturing using biotinylated-Ab/SA magnetic beads rather than covalently bound antibody, improved reproducibility as measured by minimal inter-and intra-day variability, as well as minimal analyst-to-analyst variability. The semi-automated MAPPs workflow improved sensitivity, allowing for a lower number of cells per analysis. The method was assessed using five different biotherapeutics with varying immunogenicity rates ranging from 0.1 to 48% ADA incidence in the clinic. Biotherapeutics with ≥10%immunogenicity incidence consistently presented more peptides (1.8-28 fold) and clusters (10-21 fold) compared to those with <10% immunogenicity incidence. Our semi-automated MAPPs method provided two main advantages over a manual workflow- the robustness and reproducibility affords confidence in the epitopes identified from as few as 5 to 10 donors and the method workflow can be readily adapted to incorporate different capture Abs in addition to anti-HLA-DR. The incorporation of semi-automated MAPPs with biotinylated-Ab/SA bead-based capture in immunogenicity screening strategies allows the generation of more consistent and reliable data, helping to improve immunogenicity prediction capabilities in drug development. MHC associated peptide proteomics (MAPPs), Immunogenicity risk assessment, in vitro/ex vivo, biotherapeutics, Major Histocompatibility Complex Class II (MHC II), LC-MS, Immunoaffinity Capture, streptavidin magnetic beads.

In Silico Analyses, Experimental Verification and Application in DNA Vaccines of Ebolavirus GP-Derived pan-MHC-II-Restricted Epitopes.

(1) Background and Purpose: Ebola virus (EBOV) is the causative agent of Ebola virus disease (EVD), which causes extremely high mortality and widespread epidemics. The only glycoprotein (GP) on the surface of EBOV particles is the key to mediating viral invasion into host cells. DNA vaccines for EBOV are in development, but their effectiveness is unclear. The lack of immune characteristics resides in antigenic MHC class II reactivity. (2) Methods: We selected MHC-II molecules from four human leukocyte antigen II (HLA-II) superfamilies with 98% population coverage and eight mouse H2-I alleles. IEDB, NetMHCIIpan, SYFPEITHI, and Rankpep were used to screen MHC-II-restricted epitopes with high affinity for EBOV GP. Further immunogenicity and conservation analyses were performed using VaxiJen and BLASTp, respectively. EpiDock was used to simulate molecular docking. Cluster analysis and binding affinity analysis of EBOV GP epitopes and selected MHC-II molecules were performed using data from NetMHCIIpan. The selective GP epitopes were verified by the enzyme-linked immunospot (ELISpot) assay using splenocytes of BALB/c (H2d), C3H, and C57 mice after DNA vaccine pVAX-GPEBO immunization. Subsequently, BALB/c mice were immunized with Protein-GPEBO, plasmid pVAX-GPEBO, and pVAX-LAMP/GPEBO, which encoded EBOV GP. The dominant epitopes of BALB/c (H-2-I-AdEd genotype) mice were verified by the enzyme-linked immunospot (ELISpot) assay. It is also used to evaluate and explore the advantages of pVAX-LAMP/GPEBO and the reasons behind them. (3) Results: Thirty-one HLA-II-restricted and 68 H2-I-restricted selective epitopes were confirmed to have high affinity, immunogenicity, and conservation. Nineteen selective epitopes have cross-species reactivity with good performance in MHC-II molecular docking. The ELISpot results showed that pVAX-GPEBO could induce a cellular immune response to the synthesized selective peptides. The better immunoprotection of the DNA vaccines pVAX-LAMP/GPEBO coincides with the enhancement of the MHC class II response. (4) Conclusions: Promising MHC-II-restricted candidate epitopes of EBOV GP were identified in humans and mice, which is of great significance for the development and evaluation of Ebola vaccines.

Efficacy of Raphamin against Pneumococcal Infection: a Preclinical Study.

The aim of the study was to evaluate the activity of Raphamin in a model of non-lethal pneumococcal infection caused by Streptococcus pneumoniae 3 in BALB/c mice. The drug or placebo was administered intragastrically 3 days prior to infection, 2 h before and 2 h post infection, and then for 3 full days, alone or in combination with antibiotic (amoxicil-lin/clavulanic acid). Raphamin monotherapy significantly decreased bacterial load in the lungs in comparison with placebo (p<0.05) which was comparable to the effect in antibiotic alone or combined with Raphamin. Raphamin prevented reproduction of Streptococcus pneumoniae in the lower respiratory tract and its combination with the antibiotic was safe and did not reduce the efficacy of amoxicillin/clavulanic acid.

Comprehensive immunophenotyping of solid tumor-infiltrating immune cells reveals the expression characteristics of LAG-3 and its ligands.

Background: Immune cell expression profiling from patient samples is critical for the successful development of immuno-oncology agents and is useful to understand mechanism-of-action, to identify exploratory biomarkers predictive of response, and to guide treatment selection and combination therapy strategies. LAG-3 is an inhibitory immune checkpoint that can suppress antitumor T-cell responses and targeting LAG-3, in combination with PD-1, is a rational approach to enhance antitumor immunity that has recently demonstrated clinical success. Here, we sought to identify human immune cell subsets that express LAG-3 and its ligands, to characterize the marker expression profile of these subsets, and to investigate the potential relationship between LAG-3 expressing subsets and clinical outcomes to immuno-oncology therapies. Methods: Comprehensive high-parameter immunophenotyping was performed using mass and flow cytometry of tumor-infiltrating lymphocytes (TILs) and peripheral blood mononuclear cells (PBMCs) from two independent cohorts of samples from patients with various solid tumor types. Profiling of circulating immune cells by single cell RNA-seq was conducted on samples from a clinical trial cohort of melanoma patients treated with immunotherapy. Results: LAG-3 was most highly expressed by subsets of tumor-infiltrating CD8 T central memory (TCM) and effector memory (TEM) cells and was frequently co-expressed with PD-1. We determined that these PD-1+ LAG-3+ CD8 memory T cells exhibited a unique marker profile, with greater expression of activation (CD69, HLA-DR), inhibitory (TIM-3, TIGIT, CTLA-4) and stimulatory (4-1BB, ICOS) markers compared to cells that expressed only PD-1 or LAG-3, or that were negative for both checkpoints. In contrast to tumors, LAG-3 expression was more limited in circulating immune cells from healthy donors and solid tumor patients. Additionally, we found abundant expression of the LAG-3 ligands MHC-II and galectin-3 in diverse immune cell types, whereas FGL1 and LSECtin were minimally expressed by immune cells in the tumor microenvironment (TME). Lastly, we found an inverse relationship between baseline and on-treatment levels of circulating LAG3 transcript-expressing CD8 memory T cells and response to combination PD-1 and CTLA-4 blockade in a clinical trial cohort of melanoma patients profiled by scRNAseq. Conclusions: These results provide insights into the nature of LAG-3- and ligand-expressing immune cells within the TME, and suggest a biological basis for informing mechanistic hypotheses, treatment selection strategies, and combination immunotherapy approaches to support continued development of dual PD-1 and LAG-3 blockade.

Case report: A late and isolated presentation of meningoencephalomyelitis uncovers a novel pathogenic variant in the CIITA gene.

Background: Bare lymphocyte syndrome type II (BLS II) is a rare form of severe combined immunodeficiency caused by mutations in the CIITA gene, which regulates major histocompatibility complex class II (MHC II) expression. Objective: We report the case of a Saudi boy with a novel mutation in the CIITA gene who presented with acute and late meningoencephalomyelitis, resulting in severe neurodevelopmental regression. Methods: We reviewed the patient's clinical and laboratory data obtained from medical records and performed a literature search on BLS II. Results: The patient presented with acute meningoencephalomyelitis confirmed by MRI findings and was later found to carry a homozygous pathogenic variant in the CIITA gene p.(Leu473Hisfs*15). The patient had no MCH II expression, confirming the genetic diagnosis of autosomal recessive BLS II. Surprisingly, the patient's prior clinical history was unremarkable for significant infections or autoimmunity. Conclusions: We report a case with a novel CIITA gene mutation presenting atypically with a late and isolated severe infection. Isolated severe meningoencephalomyelitis may be a manifestation of primary immunodeficiency.

The effect of edible bird's nests on the expression of MHC-II and costimulatory molecules of C57BL/6 mouse splenocytes.

The glutinous nest that builds by the saliva secretion of swiftlet is recognizable as an edible bird's nest (EBN). It enriched a medicinal value and was regarded as supplementary food that exerts various beneficial health effects, especially immune boosters. This study's objective was to determine the impact of EBN on the expression of MHC-II and costimulatory molecules (CD86 and CD80) related to the initiation of T-cell activation. Both rEBN and pEBN samples were prepared with simulated gastrointestinal digestion for enhancing the bioaccessibility of bioactive compounds. Our result showed that digested EBN samples slightly influence the upregulation of MHC-II, CD86, and CD80 in gene expression of LPS-stimulated Raw 264.7 cells. The concern of endotoxin contamination in EBN samples, which may cause a false-positive result, was measured by quantitative PCR. We found that the inflammatory genes (IL-1ß and TNF-α) were not induced by EBN treatments. Moreover, cell surface protein expression in splenocytes treated with EBN was assessed using flow cytometric analysis. Digested EBN samples demonstrated their capacity to promote the elevation of MHC-II, CD86, and CD80 cell surface protein expression. Finally, the digested-EBN-treated splenocytes only exhibited a specific response in the T-cells population. Thus, EBN is a source of the bioactive compound that has been proposed to exert a role in the stimulation of both MHC-II and costimulatory molecules for TCR/pMHC-II interaction leading to T-cell activation.

The aging kidney is characterized by tubuloinflammaging, a phenotype associated with MHC-II gene expression.

Introduction: Even during physiologic aging, the kidney experiences a loss of mass and a progressive functional decline. This is clinically relevant as it leads to an increased risk of acute and chronic kidney disease. The kidney tubular system plays an important role in the underlying aging process, but the involved cellular mechanisms remain largely elusive. Methods: Kidneys of 3-, 12- and 24-month-old male C57BL/6J mice were used for RNA sequencing, histological examination, immunostaining and RNA-in-situ-hybridization. Single cell RNA sequencing data of differentially aged murine and human kidneys was analyzed to identify age-dependent expression patterns in tubular epithelial cells. Senescent and non-senescent primary tubular epithelial cells from mouse kidney were used for in vitro experiments. Results: During normal kidney aging, tubular cells adopt an inflammatory phenotype, characterized by the expression of MHC class II related genes. In our analysis of bulk and single cell transcriptional data we found that subsets of tubular cells show an age-related expression of Cd74, H2-Eb1 and H2-Ab1 in mice and CD74, HLA-DQB1 and HLADRB1 in humans. Expression of MHC class II related genes was associated with a phenotype of tubular cell senescence, and the selective elimination of senescent cells reversed the phenotype. Exposure to the Cd74 ligand MIF promoted a prosenescent phenotype in tubular cell cultures. Discussion: Together, these data suggest that during normal renal aging tubular cells activate a program of 'tubuloinflammaging', which might contribute to age-related phenotypical changes and to increased disease susceptibility.