A fetal wave of human type 3 effector gamma delta cells with restricted TCR diversity persists into adulthood

Accumulating evidence suggests that the mouse embryonic thymus produces distinct waves of innate effector gamma delta T cells. However, it is unclear whether this process occurs similarly in humans and whether it comprises a dedicated subset of innate-like type 3 effector gamma delta T cells. Here, we present a protocol for high-throughput sequencing of TRG and TRD pairs that comprise the clonal gamma delta TCR. In combination with single-cell RNA sequencing, multiparameter flow cytometry, and TCR sequencing, we reveal a high heterogeneity of gamma delta T cells sorted from neonatal and adult blood that correlated with TCR usage. Immature gamma delta T cell clusters displayed mixed and diverse TCRs, but effector cell types segregated according to the expression of either highly expanded individual V delta 1(+) TCRs or moderately expanded semi-invariant V gamma 9V delta 2(+) TCRs. The V gamma 9V delta 2(+) T cells shared expression of genes that mark innate-like T cells, including ZBTB16 (encoding PLZF), KLRB1, and KLRC1, but consisted of distinct clusters with unrelated V gamma 9V delta 2(+) TCR clones characterized either by TBX21, FCGR3A, and cytotoxicity-associated gene expression (type 1) or by CCR6, RORC, IL23R, and DPP4 expression (type 3). Effector gamma delta T cells with type 1 and type 3 innate T cell signatures were detected in a public dataset of early embryonic thymus organogenesis. Together, this study suggests that functionally distinct waves of human innate-like effector gamma delta T cells with semi-invariant V gamma 9V delta 2(+) TCR develop in the early fetal thymus and persist into adulthood

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer‐reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state‐of‐the‐art handbook for basic and clinical researchers.DFG, 389687267, Kompartimentalisierung, Aufrechterhaltung und Reaktivierung humaner Gedächtnis-T-Lymphozyten aus Knochenmark und peripherem BlutDFG, 80750187, SFB 841: Leberentzündungen: Infektion, Immunregulation und KonsequenzenEC/H2020/800924/EU/International Cancer Research Fellowships - 2/iCARE-2DFG, 252623821, Die Rolle von follikulären T-Helferzellen in T-Helferzell-Differenzierung, Funktion und PlastizitätDFG, 390873048, EXC 2151: ImmunoSensation2 - the immune sensory syste

A clonotypic Vγ4Jγ1/Vδ5Dδ2Jδ1 innate γδ T-cell population restricted to the CCR6⁺CD27⁻ subset.

Here we investigate the TCR repertoire of mouse Vγ4(+) γδ T cells in correlation with their developmental origin and homeostasis. By deep sequencing we identify a high frequency of straight Vδ5Dδ2Jδ1 germline rearrangements without P- and N-nucleotides within the otherwise highly diverse Trd repertoire of Vγ4(+) cells. This sequence is infrequent in CCR6(-)CD27(+) cells, but abundant among CCR6(+)CD27(-) γδ T cells. Using an inducible Rag1 knock-in mouse model, we show that γδ T cells generated in the adult thymus rarely contain this germline-rearranged Vδ5Dδ2Jδ1 sequence, confirming its fetal origin. Single-cell analysis and deep sequencing of the Trg locus reveal a dominant CDR3 junctional motif that completes the TCR repertoire of invariant Vγ4(+)Vδ5(+) cells. In conclusion, this study identifies an innate subset of fetal thymus-derived γδ T cells with an invariant Vγ4(+)Vδ5(+) TCR that is restricted to the CCR6(+)CD27(-) subset of γδ T cells

Thymic γδ T cells in the absence of miR-181a/b-1.

<p>(A) Expression analysis of miR-181a in FACS-sorted thymocytes pooled from 5 adult or 8 neonatal TcrdH2BeGFP mice. Expression levels of the indicated cell populations were analyzed by quantitative RT-PCR and normalized to snoRNA 412. Error bars show range of relative expression levels from triplicates. (B) Bar graph shows absolute γδ T cell numbers in miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) compared to TcrdH2BeGFP and miR-181a/b-1^+/–x TcrdH2BeGFP controls (ctrl.), pooled data from five independent experiments with each 2–5 mice per group, mean + SD. (C) Expression analysis of miR-181d in FACS-sorted thymocytes pooled from 5 miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) and TcrdH2BeGFP controls (ctrl.). One representative experiment of two independent experiments that gave similar results. Expression levels of the indicated cell populations were analyzed by quantitative RT-PCR and normalized to snoRNA 412. Error bars show range of relative expression levels from triplicates. (D–I) FACS analysis of thymic γδ T cells in–/–mice compared to ctrl mice (D, F-I) and mixed bone marrow chimeras (E). (D) Vγ usage of thymic γδ T cells (gated on Tcrβ^–GFP^hi cells). Scatter plot shows pooled data from five experiments with 3–6 mice per group, one dot represents one mouse, mean. (E) Flow cytometric analysis of 1:1 mixed bone marrow chimeras. Scatter plot shows ratios of miR-181a/b-1^–/–(KO) and miR-181a/b-1 sufficient wild type (WT) donor Vγ1⁺ and Vγ4⁺ cells among all lymphocytes, respectively. Data are pooled from two independent experiments with each 3 mice per group, harmonic mean. (F) Scatter plot shows absolute numbers of NK1.1⁺ cells, pooled data from five independent experiments with each 2–5 mice per group. (G) Scatter plot shows absolute numbers of NK1.1⁺ γδ T cells, pooled data from five independent experiments with each 2–5 mice per group. (H) Representative contour plots of cluster B (CD44^hiCD24^–) and cluster A (CD44^–/loCD24⁺) γδ thymocytes (gated on Tcrβ^–GFP^hi cells), numbers indicate mean +/–SD of pooled data from four independent experiments with each 2–5 mice per group. (I) Representative contour plots of CCR6⁺ and NK1.1⁺ cluster B cells, numbers indicate mean +/–SD of pooled data from four independent experiments with each 2–6 mice per group. Statistical analyses were performed using the Mann-Whitney test.</p

γδ NKT cells fill empty iNKT liver niches in miR-181a/b-1 deficient mice.

<p>FACS analysis of liver lymphocytes of miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) compared to TcrdH2BeGFP and miR-181a/b-1^+/–x TcrdH2BeGFP controls (here referred to as ctrl.). (A + B) Analysis of αβ and γδ NKT cells in miR181a/b-1 deficient mice compared to controls. (A) Representative contour plots illustrating the gating strategy for the indicated cell populations in (B). (B) Scatter plot shows frequencies of the indicated cell populations among lymphocytes after doublets were excluded, gated as depicted in (A), pooled data from three independent experiments with each 3–4 mice per group, mean. (C) Bar graph shows total γδ NKT cell numbers, pooled data from 3 independent experiments, each n = 3–4 mice per group, mean + SD. (D) Flow cytometric analysis of 1:1 mixed bone marrow chimeras. Scatter plot shows ratios of miR-181a/b-1^–/–(KO) and miR-181a/b-1 sufficient wild type (WT) donor cells among all lymphocytes, αβ vNKT, αβ iNKT and γδ NKT lymphocytes, respectively, pooled data from two independent experiments with each 4 mice per group, harmonic mean. (E) Scatter plot shows frequencies of INFγ⁺ cells among γδ T cells, pooled data from three independent experiments with each 2–5 mice per group, mean. (F) Vγ usage of liver γδ T cells (gated on Tcrβ^–GFP^hi cells). Bar graph shows pooled data from five experiments with 3–6 mice per group, mean + SD. (G) Analysis of liver Vγ1⁺Vδ6.3⁺ γδ T cells. Scatter plot shows frequencies of Vγ1⁺Vδ6.3⁺ cells among γδ T cells, pooled data from five independent experiments with each 2–5 mice per group, mean. Statistical analyses were performed using the Mann-Whitney test.</p

Unchanged peripheral lymph node γδ T cell compartment in the absence of miR-181a/b-1.

<p>FACS analysis of γδ T cells in pLN of miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) compared to miR-181a/b-1 sufficient controls, TcrdH2BeGFP and miR-181a/b-1^+/–x TcrdH2BeGFP mice (here referred to as ctrl.). (A) Total γδ T cells numbers in pLN of the indicated phenotypes. Scatter plot shows pooled data from five independent experiment with n = 2–5 mice per group, mean. (B) Scatter plot shows absolute numbers of NK1.1⁺ γδ T cells, pooled data from five independent experiments with each 2–5 mice per group, mean. (C) Vγ usage of γδ T cells (gated on Tcrβ^–GFP^hi cells). Bar graph shows pooled data from 5 experiments with 3–6 mice per group, mean + SD. (D + E) Intracellular cytokine staining for IFN-γ and IL-17A gated on γδ T cells. (D) Representative contour plots of two independent experiments with similar outcome, with each n = 2–5 mice per group. Numbers indicate mean +/–SD from pooled data. (E) Bar gaph shows pooled data from the two independent experiments, mean + SD. Statistical analyses were performed using the Mann-Whitney test.</p

γδ NKT cells replenish empty niches of missing liver αβ iNKT cells independent of TCR specificity for CD1d.

<p>FACS analysis of liver lymphocytes stained for CD1d/PBS-57 tetramer (CD1d tet) binding. Contour plots show representative CD1d tet binding versus γδ-GFP reporter fluorescence from two independent experiments, with each involving 3 mice per group of miR-181a/b-1 deficient (–/–) and miR-181a/b-1 sufficient (ctrl.) mice.</p

Dendritic epidermal T cells develop in the absence of miR-181a/b-1.

<p>(A) Analysis of Vγ5⁺ γδ T cells in the skin of miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) compared to TcrdH2BeGFP mice (ctrl.). (left) Representative contour plots illustrating the gating for Vγ5⁺ γδ T cells. (right) Scatter plot shows frequencies of Vγ5⁺ γδ T cells, pooled data from two independent experiments with each n = 3 mice per group, mean. (B) Histological analysis of epidermal sheets from ears of miR-181a/b-1^–/–x TcrdH2BeGFP mice (–/–) compared to TcrdH2BeGFP mice (ctrl.). Epidermal sheets were stained for DETCs (yellow, overlay red and green) with CD3 (red) and TcrdGFP⁺ (green) cells indicate γδ T cells. Original magnification: 20x, scale bars: 20μm.</p

Lyz2-Cre-Mediated Genetic Deletion of Septin7 Reveals a Role of Septins in Macrophage Cytokinesis and Kras-Driven Tumorigenesis

By crossing septin7-floxed mice with Lyz2-Cre mice carrying the Cre recombinase inserted in the Lysozyme-M (Lyz2) gene locus we aimed the specific deletion of septin7 in myeloid cells, such as monocytes, macrophages and granulocytes. Septin7flox/flox:Lyz2-Cre mice show no alterations in the myeloid compartment. Septin7-deleted macrophages (BMDMs) were isolated and analyzed. The lack of Septin7 expression was confirmed and a constitutive double-nucleation was detected in Septin7-deficient BMDMs indicating a defect in macrophage cytokinesis. However, phagocytic function of macrophages as judged by uptake of labelled E. coli particles and LPS-stimulated macrophage activation as judged by induction of TNF mRNA expression and TNF secretion were not compromised. In addition to myeloid cells, Lyz2-Cre is also active in type II pneumocytes (AT2 cells). We monitored lung adenocarcinoma formation in these mice by crossing them with the conditional knock-in Kras-LSL-G12D allele. Interestingly, we found that control mice without septin7 depletion die after 3–5 weeks, while the Septin7-deficient animals survived 11 weeks or even longer. Control mice sacrificed in the age of 4 weeks display a bronchiolo-alveolar hyperplasia with multiple adenomas, whereas the Septin7-deficient animals of the same age are normal or show only a weak multifocal brochiolo-alveolar hyperplasia. Our findings indicate an essential role of Septin7 in macrophage cytokinesis but not in macrophage function. Furthermore, septin7 seems absolutely essential for oncogenic Kras-driven lung tumorigenesis making it a potential target for anti-tumor interventions