Generation of antitumor chimeric antigen receptors incorporating T cell signaling motifs.

Chimeric antigen receptor (CAR) T cells have been used to successfully treat various blood cancers, but adverse effects have limited their potential. Here, we developed chimeric adaptor proteins (CAPs) and CAR tyrosine kinases (CAR-TKs) in which the intracellular ζ T cell receptor (TCRζ) chain was replaced with intracellular protein domains to stimulate signaling downstream of the TCRζ chain. CAPs contain adaptor domains and the kinase domain of ZAP70, whereas CAR-TKs contain only ZAP70 domains.

Diet-mediated constitutive induction of novel IL-4+ ILC2 cells maintains intestinal homeostasis in mice.

Group 2 innate lymphoid cells (ILC2s) expressing IL-5 and IL-13 are localized at various mucosal tissues and play critical roles in the induction of type 2 inflammation, response to helminth infection, and tissue repair. Here, we reveal a unique ILC2 subset in the mouse intestine that constitutively expresses IL-4 together with GATA3, ST2, KLRG1, IL-17RB, and IL-5. In this subset, IL-4 expression is regulated by mechanisms similar to but distinct from those observed in T cells and is partly affected by IL-25 signaling.

Severe CD8+ T Lymphopenia in WHIM Syndrome Caused by Selective Sequestration in Primary Immune Organs.

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is an ultra-rare combined primary immunodeficiency disease caused by heterozygous gain-of-function mutations in the chemokine receptor CXCR4. WHIM patients typically present with recurrent acute infections associated with myelokathexis (severe neutropenia due to bone marrow retention of mature neutrophils). Severe lymphopenia is also common, but the only associated chronic opportunistic pathogen is human papillomavirus and mechanisms are not clearly defined.

Intravenous nanoparticle vaccination generates stem-like TCF1 neoantigen-specific CD8 T cells.

Personalized cancer vaccines are a promising approach for inducing T cell immunity to tumor neoantigens. Using a self-assembling nanoparticle vaccine that links neoantigen peptides to a Toll-like receptor 7/8 agonist (SNP-7/8a), we show how the route and dose alter the magnitude and quality of neoantigen-specific CD8 T cells. Intravenous vaccination (SNP-IV) induced a higher proportion of TCF1PD-1CD8 T cells as compared to subcutaneous immunization (SNP-SC).

Author Correction: Requirements for the differentiation of innate T-bet memory-phenotype CD4 T lymphocytes under steady state.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Requirements for the differentiation of innate T-bet memory-phenotype CD4 T lymphocytes under steady state.

CD4 T lymphocytes consist of naïve, antigen-specific memory, and memory-phenotype (MP) cell compartments at homeostasis. We recently showed that MP cells exert innate-like effector function during host defense, but whether MP CD4 T cells are functionally heterogeneous and, if so, what signals specify the differentiation of MP cell subpopulations under homeostatic conditions is still unclear. Here we characterize MP lymphocytes as consisting of T-bet, T-bet, and T-bet subsets, with innate, Th1-like effector activity exclusively associated with T-bet cells.

Thymic stromal lymphopoietin drives the development of IL-13 Th2 cells.

T helper 2 (Th2) cells are pivotal in the development of allergy. Allergen exposure primes IL-4 Th2 cells in lymph node, but production of effector cytokines including IL-5 and IL-13 is thought to require additional signals from antigen and the environment. Here we report that a substantial proportion of naive CD4 T cells in spleen and lymph node express receptors for the epithelium-derived inflammatory cytokine thymic stromal lymphopoietin (TSLP).

Memory-phenotype CD4 T cells spontaneously generated under steady-state conditions exert innate T1-like effector function.

Conventional CD4 T cells are composed of naïve, pathogen-specific memory, and pathogen-independent memory-phenotype (MP) cells under steady state. Naïve and pathogen-specific memory cells play key roles in adaptive immunity, whereas the homeostatic mechanisms regulating the generation of MP cells and their biological functions are unclear. We show that MP cells are autonomously generated from peripheral naïve cells in the absence of infectious stimulation in a T cell receptor (TCR)- and CD28-dependent manner.

Microbiota-Dependent Activation of an Autoreactive T Cell Receptor Provokes Autoimmunity in an Immunologically Privileged Site.

Activated retina-specific T cells that have acquired the ability to break through the blood-retinal barrier are thought to be causally involved in autoimmune uveitis, a major cause of human blindness. It is unclear where these autoreactive T cells first become activated, given that their cognate antigens are sequestered within the immune-privileged eye. We demonstrate in a novel mouse model of spontaneous uveitis that activation of retina-specific T cells is dependent on gut commensal microbiota.

CD326(lo)CD103(lo)CD11b(lo) dermal dendritic cells are activated by thymic stromal lymphopoietin during contact sensitization in mice.

The cytokine thymic stromal lymphopoietin (TSLP) is produced by epithelia exposed to the contact sensitizer dibutyl phthalate (DBP), and it is critical for the induction of Th2 immune responses by DBP-FITC. TSLP is thought to act on dendritic cells (DC), but the precise DC subsets involved in the response to TSLP remain to be fully characterized. In this study we show that a subset of CD326(lo)CD103(lo)CD11b(lo) dermal DC, which we termed "triple-negative (TN) DC," is highly responsive to TSLP.

Lipid phosphatases identified by screening a mouse phosphatase shRNA library regulate T-cell differentiation and protein kinase B AKT signaling.

Screening a complete mouse phosphatase lentiviral shRNA library using high-throughput sequencing revealed several phosphatases that regulate CD4 T-cell differentiation. We concentrated on two lipid phosphatases, the myotubularin-related protein (MTMR)9 and -7. Silencing MTMR9 by shRNA or siRNA resulted in enhanced T-helper (Th)1 differentiation and increased Th1 protein kinase B (PKB)/AKT phosphorylation while silencing MTMR7 caused increased Th2 and Th17 differentiation and increased AKT phosphorylation in these cells.

Early signaling events that underlie fate decisions of naive CD4(+) T cells toward distinct T-helper cell subsets.

CD4(+) T-helper (Th) cells are a major cell population that play an important role in governing acquired immune responses to a variety of foreign antigens as well as inducing some types of autoimmune diseases. There are at least four distinct Th cell subsets (Th1, Th2, Th17, and inducible T-regulatory cells), each of which has specialized functions to control immune responses. Each of these cell types emerge from naive CD4(+) T cells after encounter with foreign antigens presented by dendritic cells (DCs).

Cytokines of the γ(c) family control CD4+ T cell differentiation and function.

Naive CD4(+) T cells undergo massive proliferation and differentiation into at least four distinct helper T cell subsets after recognition of foreign antigen-derived peptides presented by dendritic cells. Each helper T cell subset expresses a distinct set of genes that encode unique transcription factor(s), as well as hallmark cytokines. The cytokine environment created by activated CD4(+) T cells, dendritic cells and/or other cell types during the course of differentiation is a major determinant for the helper T cell fate.

The transcription factor T-bet is induced by multiple pathways and prevents an endogenous Th2 cell program during Th1 cell responses.

T-bet is a critical transcription factor for T helper 1 (Th1) cell differentiation. To study the regulation and functions of T-bet, we developed a T-bet-ZsGreen reporter mouse strain. We determined that interleukin-12 (IL-12) and interferon-γ (IFN-γ) were redundant in inducing T-bet in mice infected with Toxoplasma gondii and that T-bet did not contribute to its own expression when induced by IL-12 and IFN-γ.

Memory CD4+ T cells: fate determination, positive feedback and plasticity.

Naïve CD4(+) T cells undergo massive cell proliferation upon encountering their cognate ligand. This proliferation depends upon appropriate cues from the antigen-presenting cells that have processed the antigen and present the peptide to the T cells, and requires the establishment of a cytokine environment that can support such proliferation. Expansion of antigen-specific CD4(+) T cells needs to be coupled with differentiation into one of several effector/regulatory phenotypes if the priming event is to result in cells that can initially act to control the particular pathogen that elicited the response, and later to serve as memory cells to insure an appropriate response upon reintroduction of the pathogen.

Differentiation of effector CD4 T cell populations (*).

CD4 T cells play critical roles in mediating adaptive immunity to a variety of pathogens. They are also involved in autoimmunity, asthma, and allergic responses as well as in tumor immunity. During TCR activation in a particular cytokine milieu, naive CD4 T cells may differentiate into one of several lineages of T helper (Th) cells, including Th1, Th2, Th17, and iTreg, as defined by their pattern of cytokine production and function.

Tpl2 kinase regulates T cell interferon-gamma production and host resistance to Toxoplasma gondii.

Tpl2 (Tumor progression locus 2), also known as Cot/MAP3K8, is a hematopoietically expressed serine-threonine kinase. Tpl2 is known to have critical functions in innate immunity in regulating tumor necrosis factor-alpha, Toll-like receptor, and G protein-coupled receptor signaling; however, our understanding of its physiological role in T cells is limited. We investigated the potential roles of Tpl2 in T cells and found that it was induced by interleukin-12 in human and mouse T cells in a Stat4-dependent manner.

Tuning sensitivity to IL-4 and IL-13: differential expression of IL-4Ralpha, IL-13Ralpha1, and gammac regulates relative cytokine sensitivity.

Interleukin (IL)-4 and -13 are related cytokines sharing functional receptors. IL-4 signals through the type I (IL-4Ralpha/common gamma-chain [gammac]) and the type II (IL-4Ralpha/-13Ralpha1) IL-4 receptors, whereas IL-13 utilizes only the type II receptor. In this study, we show that mouse bone marrow-derived macrophages and human and mouse monocytes showed a much greater sensitivity to IL-4 than to IL-13.

GATA-3 promotes Th2 responses through three different mechanisms: induction of Th2 cytokine production, selective growth of Th2 cells and inhibition of Th1 cell-specific factors.

Naïve CD4 T cells can differentiate into at least two different types of T helpers, Th1 and Th2 cells. Th2 cells, capable of producing IL-4, IL-5 and IL-13, are involved in humoral immunity against extracellular pathogens and in the induction of asthma and other allergic diseases. In this review, we summarize recent reports regarding the transcription factors involved in Th2 differentiation and cell expansion, including Stat5, Gfi-1 and GATA-3.

Independent roles for IL-2 and GATA-3 in stimulating naive CD4+ T cells to generate a Th2-inducing cytokine environment.

T cell receptor (TCR) signaling plays an important role in early interleukin (IL)-4 production by naive CD4+ T cells. This "antigen-stimulated" early IL-4 is sufficient for in vitro Th2 differentiation. Here, we provide evidence that early IL-4 production by naive CD4+ T cells stimulated with cognate peptide requires TCR-induced early GATA-3 expression and IL-2 receptor signaling, both of which are controlled by the degree of activation of extracellular signal-regulated kinase (ERK).

Spontaneous and homeostatic proliferation of CD4 T cells are regulated by different mechanisms.

Transfer of naive CD4 T cells into lymphopenic mice initiates a proliferative response of the transferred cells, often referred to as homeostatic proliferation. Careful analysis reveals that some of the transferred cells proliferate rapidly and undergo robust differentiation to memory cells, a process we have designated spontaneous proliferation, and other cells proliferate relatively slowly and show more limited evidence of differentiation. In this study we report that spontaneous proliferation is IL-7 independent, whereas the slow proliferation (referred to as homeostatic proliferation) is IL-7 dependent.