Host conditioning with IL-1β improves the antitumor function of adoptively transferred T cells.

Host conditioning has emerged as an important component of effective adoptive cell transfer-based immunotherapy for cancer. High levels of IL-1β are induced by host conditioning, but its impact on the antitumor function of T cells remains unclear. We found that the administration of IL-1β increased the population size and functionality of adoptively transferred T cells within the tumor.

Cytokine regulation of lung Th17 response to airway immunization using LPS adjuvant.

Infections caused by bacteria in the airway preferentially induce a Th17 response. However, the mechanisms involved in the regulation of CD4 T-cell responses in the lungs are incompletely understood. Here, we have investigated the mechanisms involved in the regulation of Th17 differentiation in the lungs in response to immunization with lipopolysaccharide (LPS) as an adjuvant.

Innate immunological function of TH2 cells in vivo.

Type 2 helper T cells (TH2 cells) produce interleukin 13 (IL-13) when stimulated by papain or house dust mite extract (HDM) and induce eosinophilic inflammation. This innate response is dependent on IL-33 but not T cell antigen receptors (TCRs). While type 2 innate lymphoid cells (ILC2 cells) are the dominant innate producers of IL-13 in naive mice, we found here that helminth-infected mice had more TH2 cells compared to uninfected mice, and thes e cells became major mediators of innate type 2 responses.

IL-25-responsive, lineage-negative KLRG1(hi) cells are multipotential 'inflammatory' type 2 innate lymphoid cells.

Innate lymphoid cells (ILCs) are lymphocyte-like cells that lack T cell or B cell antigen receptors and mediate protective and repair functions through cytokine secretion. Among these, type 2 ILCs (ILC2 cells) are able to produce type 2 cytokines. We report the existence of an inflammatory ILC2 (iILC2) population responsive to interleukin 25 (IL-25) that complemented IL-33-responsive natural ILC2 (nILC2) cells.

Efficient cytokine-induced IL-13 production by mast cells requires both IL-33 and IL-3.

Background: IL-13 is a critical effector cytokine for allergic inflammation. It is produced by several cell types, including mast cells, basophils, and TH2 cells. In mast cells and basophils its induction can be stimulated by cross-linkage of immunoglobulin receptors or cytokines.

IL-1 enhances expansion, effector function, tissue localization, and memory response of antigen-specific CD8 T cells.

Here, we show that interleukin-1 (IL-1) enhances antigen-driven CD8 T cell responses. When administered to recipients of OT-I T cell receptor transgenic CD8 T cells specific for an ovalbumin (OVA) peptide, IL-1 results in an increase in the numbers of wild-type but not IL1R1(-/-) OT-I cells, particularly in spleen, liver, and lung, upon immunization with OVA and lipopolysaccharide. IL-1 administration also results in an enhancement in the frequency of antigen-specific cells that are granzyme B(+), have cytotoxic activity, and/ or produce interferon γ (IFN-γ).

IL-1 acts on T cells to enhance the magnitude of in vivo immune responses.

IL-1 strikingly enhances antigen-driven responses of CD4 and CD8 T cells. It is substantially more effective than LPS and when added to a priming regime of antigen plus LPS, it strikingly enhances cell expansion. The effect is mediated by direct action on CD4 and CD8 T cells; the response occurs when OT-I or OT-II cells are transferred to B6 IL-1R1-/- recipients and only cells that express IL-1 receptors can respond.

KLF13 sustains thymic memory-like CD8(+) T cells in BALB/c mice by regulating IL-4-generating invariant natural killer T cells.

"Memory-like T cells" are a subset of thymic cells that acquire effector function through the maturation process rather than interaction with specific antigen. Disruption of genes encoding T cell signaling proteins or transcription factors have provided insights into the differentiation of such cells. In this study, we show that in BALB/c, but not C57BL/6, mice, a large portion of thymic CD4(-)CD8(+) T cells exhibit a memory-like phenotype.

Regulation of microRNA expression and abundance during lymphopoiesis.

Although the cellular concentration of miRNAs is critical to their function, how miRNA expression and abundance are regulated during ontogeny is unclear. We applied miRNA-, mRNA-, and ChIP-Seq to characterize the microRNome during lymphopoiesis within the context of the transcriptome and epigenome. We show that lymphocyte-specific miRNAs are either tightly controlled by polycomb group-mediated H3K27me3 or maintained in a semi-activated epigenetic state prior to full expression.

IL-1 acts directly on CD4 T cells to enhance their antigen-driven expansion and differentiation.

IL-1 causes a marked increase in the degree of expansion of naïve and memory CD4 T cells in response to challenge with their cognate antigen. The response occurs when only specific CD4 T cells can respond to IL-1beta, is not induced by a series of other cytokines and does not depend on IL-6 or CD-28. When WT cells are primed in IL-1R1(-/-) recipients, IL-1 increases the proportion of cytokine-producing transgenic CD4 T cells, especially IL-17- and IL-4-producing cells, strikingly increases serum IgE levels and serum IgG1 levels.

Global mapping of H3K4me3 and H3K27me3 reveals specificity and plasticity in lineage fate determination of differentiating CD4+ T cells.

Multipotential naive CD4(+) T cells differentiate into distinct lineages including T helper 1 (Th1), Th2, Th17, and inducible T regulatory (iTreg) cells. The remarkable diversity of CD4(+) T cells begs the question whether the observed changes reflect terminal differentiation with heritable epigenetic modifications or plasticity in T cell responses. We generated genome-wide histone H3 lysine 4 (H3K4) and lysine 27 (H3K27) trimethylation maps in naive, Th1, Th2, Th17, iTreg, and natural Treg (nTreg) cells.

Blimp-1 induced by IL-4 plays a critical role in suppressing IL-2 production in activated CD4 T cells.

Although an inhibitory function of IL-4 in CD4 T cell IL-2 production has long been recognized, a mechanism mediating the inhibition remains unclear. In this study we demonstrate that IL-4 displays a potent suppressive function in IL-2 production of activated CD4 T cells through STAT6. IL-4-induced IL-2 suppression required IL-2 because IL-2 neutralization restored the production of IL-2 even in the presence of IL-4.

In vivo studies fail to reveal a role for IL-4 or STAT6 signaling in Th2 lymphocyte differentiation.

The expression of interleukin-4 (IL-4) is viewed as the hallmark of a Th2 lymphocyte, whereas the subsequent action of IL-4 and IL-13, mediated through the STAT6 signaling pathway, is seen as a prerequisite for the full development of Th2 immune responses to parasites and allergens. G4 mice, whose IL-4 gene locus contains the fluorescent reporter eGFP, were used to quantify the number of Th2 cells that develop during Nippostrongylus brasiliensis- or allergen-induced immune responses under conditions where IL-4 or STAT6 was absent. Here, we show that deletion of IL-4 or STAT6 had little impact on the number or timing of appearance of IL-4-producing Th2 cells.

Production of TH1 and TH2 cell lines and clones.

This unit describes protocols for the generation of polyclonal T(H)1 and T(H)2 cell lines from naive CD4(+) T cells as well as for generation of antigen-specific cell lines from TCR-transgenic mice and antigen-specific T cell clones from primed mice. Also described are methods for the preparation and maintenance of alloreactive murine helper T (T(H)) lymphocyte and cytotoxic T lymphocyte (CTL) clones using the limiting dilution technique, as well as derivation of T(H) clones reactive with soluble protein antigens, including a method for the selection of either T(H)1 or T(H)2 lymphocyte subsets. These two subsets of T(H) cells exhibit helper function in different ways and can be distinguished by the patterns of cytokines they synthesize.

Gut flora antigens are not important in the maintenance of regulatory T cell heterogeneity and homeostasis.

CD25(+) regulatory T cells (Treg) are a heterogeneous population that exists as CD44(low) and CD44(high) cells. Here we report that while both CD44(low) and CD44(high) Treg are anergic and express similar levels of Foxp3, CD44(high) Treg are highly proliferative in vivo and are more potent suppressors in vitro than CD44(low) Treg. From analysis of the properties of Treg derived from germ-free mice, it was concluded that peptide antigens derived from intestinal microorganisms are not essential for the generation, in vivo proliferation or suppressive activity of Treg.

Probabilistic regulation of IL-4 production.

Among a population of uniformly differentiated TH(2) cells, only a portion express IL-4 upon stimulation and those that do often express the product of only a single allele. We review the evidence for the basis of IL-4 monoallelism and argue that it depends upon probabilistic expression of the Il4 gene. Further, we argue that probabilistic expression may provide a powerful mechanism through which certain key functions of IL-4, such as immunoglobulin class switching and determination of macrophage phenotype, may be efficiently regulated.

Probabilistic regulation in TH2 cells accounts for monoallelic expression of IL-4 and IL-13.

Il4 and Il13, closely linked genes, are expressed monoallelically in TH2 cells. Four different approaches (RNA FISH, cultures from Il13T-Il4/Il13-G4 mice, cultures from heterozygous Il13-Il4 double knockout mice, and a highly selected set of BABL/c*CAST/Ei clones displaying strong Il4 allelic bias) were utilized to study monoallelic expression of Il4 and coexpression of Il4 and Il13 on the same chromosome. There was a random probability for expression of one or two Il4 and one or two Il13 alleles; coexpression of cis and trans Il4 and Il13 alleles was equally probable.

A critical control element for interleukin-4 memory expression in T helper lymphocytes.

Naive T helper (Th) lymphocytes are induced to express the il4 (interleukin-4) gene by simultaneous signaling through the T cell receptor and the interleukin (IL)-4 receptor. Upon restimulation with antigen, such preactivated Th lymphocytes can reexpress the il4 gene independent of IL-4 receptor signaling. This memory for expression of the il4 gene depends on epigenetic modification of the il4 gene locus and an increased expression of GATA-3, the key transcription factor for Th2 differentiation.

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.

Conditional deletion of Gata3 shows its essential function in T(H)1-T(H)2 responses.

Expression of the transcription factor GATA-3 is strongly associated with T helper type 2 (T(H)2) differentiation, but genetic evidence for its involvement in this process has been lacking. Here, we generated a conditional GATA-3-deficient mouse line. In vitro deletion of Gata3 diminished both interleukin 4 (IL-4)-dependent and IL-4-independent T(H)2 cell differentiation; without GATA-3, T(H)1 differentiation occurred in the absence of IL-12 and interferon-gamma.

Basophils produce IL-4 and accumulate in tissues after infection with a Th2-inducing parasite.

Using mice in which the eGfp gene replaced the first exon of the Il4 gene (G4 mice), we examined production of interleukin (IL)-4 during infection by the intestinal nematode Nippostrongylus brasiliensis (Nb). Nb infection induced green fluorescent protein (GFP)pos cells that were FcepsilonRIpos, CD49bbright, c-kitneg, and Gr1neg. These cells had lobulated nuclei and granules characteristic of basophils.

Interleukin 2 plays a central role in Th2 differentiation.

Differentiation of naïve CD4 T cells into T helper (Th) 2 cells requires signaling through the T cell receptor and an appropriate cytokine environment. IL-4 is critical for such Th2 differentiation. We show that IL-2 plays a central role in this process.

Probabilistic regulation of IL-4 production in Th2 cells: accessibility at the Il4 locus.

IL-4 secreting and nonsecreting cells from Th2 cultures have a similar probability of producing IL-4 upon subsequent stimulation, implying that there is stochastic element in IL-4 production by stimulated Th2 cells. Purified IL-4 producers and nonproducers have similar Gata3 and c-maf mRNA expression. Il4 gene accessibility, analyzed by restriction enzyme accessibility (REA) at sites in the promoter, in the second intron (DNase I hypersensitivity sites HSII and HSIII) and in CNS-1 in the two populations was also similar.