Expression Of Signature Cytokines Research Articles

Differences in Cytokine Expression at Baseline and in Response to Mineral Stimulation by Peripheral Blood Mononuclear Cells from Podoconiosis Cases and Healthy Control Individuals.

Epidemiological, histological, and immunogenetic studies suggest that podoconiosis (a non-infectious tropical lymphoedema affecting approximately 4 million people globally) is an HLA class II-associated inflammatory condition that develops in response to an unknown trigger found in volcanic red clay soils. Silicate particles of the kaolinite and aluminum types have been identified in femoral lymph node biopsy samples from endemic area residents, suggesting a possible role in the pathogenesis of podoconiosis. We measured in vitro peripheral blood mononuclear cell cytokine responses (TNF-α, IL-1β, and IFN-γ) to stimulation with the minerals kaolinite, chlorite, and beryllium sulfate (all at 100 µM) using ELISA. Real time PCR was used to measure gene expression of signature cytokines in fresh whole blood, comparing podoconiosis patients and endemic healthy controls. Our results showed that the levels of TNF-α and IL-1β from in vitro cell cultures were significantly higher in unstimulated samples from patients compared to controls (p = 0.04 and p = 0.005, respectively). The minerals kaolinite and chlorite induced two and three-fold higher levels of IL-1β following 24 h of stimulation in healthy controls compared to patients, respectively. We did not find significant differences in mRNA expression of the cytokine genes assayed, though a slight fold increment in IL-1β and TGF-β was observed. In conclusion, our data suggest that the immune system is in a state of persistent activation in vivo in podoconiosis patients, and additional studies of immune regulation and exhaustion are needed to further characterize immune dysfunction in the pathogenesis of the disease. A better understanding of the underlying processes could lead to the development of a 'biosignature' detectable in the early reversible stages that could ultimately contribute to the elimination of this preventable, disabling, neglected tropical disease.

High-Dimensional T Helper Cell Profiling Reveals a Broad Diversity of Stably Committed Effector States and Uncovers Interlineage Relationships

CD4+ T helper (Th) cells are fundamental players in immunity. Based on the expression of signature cytokines and transcription factors, several Th subsets have been defined. Th cells are thought to be far more heterogeneous and multifunctional than originally believed, but characterization of the full diversity has been hindered by technical limitations. Here, we employ mass cytometry to analyze the diversity of Th cell responses generated invitro and in animal disease models, revealing a vast heterogeneity of effector states with distinct cytokine footprints. The diversities of cytokine responses established during primary antigen encounters in Th1- and Th2-cell-polarizing conditions are largely maintained after secondary challenge, regardless of the new inflammatory environment, highlighting many of the identified states as stable Th cell sublineages. We also find that Th17 cells tend to upregulate Th2-cell-associated cytokines upon challenge, indicating a closer developmental connection between Th17 and Th2 cells than previously anticipated.

The anti-TH17 polarization effect of Indigo naturalis and tryptanthrin by differentially inhibiting cytokine expression

The Chinese herbal medicine Qing-Dai (also known as Indigo naturalis) extracted from indigo-bearing plants including Baphicacanthus cusia (Ness) Bremek was previously reported to exhibit anti-psoriatic effects in topical treatment. TH17 was later established as a key player in the pathogenesis of psoriasis. We investigated the anti-TH17 effect of Indigo naturalis and its active compounds. The aim of this study is to evaluate the toxicity of Indigo naturalis (IN) and its derivatives on five cell types involved in psoriasis, and to study the anti-inflammatory mechanism for the toxicity. Following the fingerprint and quantity analysis of indirubin, indigo, and tryptanthrin in IN extract, we used MTS kits to measure the anti-proliferative effect of IN and three active compounds on five different cell types identified in psoriatic lesions. Quantitative RT-PCR analysis was used to measure the expression of various genes identified in the activated keratinocytes and TH17 polarized gene expression in RORγt-expressing T cells. We showed that IN differentially inhibited the proliferation of keratinocytes and endothelial cells but not monocytes, fibroblasts nor Jurkat T cells. Among three active compounds identified in IN, tryptanthrin was the most potent compound to reduce their proliferation. In addition to differentially reducing IL6 and IL8 expression, both IN and tryptanthrin also potently decreased the expression of anti-microbial S100A9 peptide, CCL20 chemokine, IL1B and TNFA cytokines, independent of NF-κB-p65-activation. Their attenuating effect was also detected on the expression of signature cytokines or chemokines induced during RORγT-induced TH17 polarization. We were the first to confirm a direct anti-TH17 effect of both IN herbal extract and tryptanthrin.

Defibrotide Modulates Pulmonary Endothelial Cell Activation and Protects Against Lung Inflammation in Pre-Clinical Models of LPS-Induced Lung Injury and Idiopathic Pneumonia Syndrome.

Background Pulmonary dysfunction remains one of the greatest challenges to the optimization of care following allogeneic blood and marrow transplantation (alloBMT). Almost half of the pneumonias that occur early after alloBMT are noninfectious, termed idiopathic pneumonia syndrome (IPS). Injury/activation to vascular endothelial cells (ECs) are believed to be directly related to several post-BMT complications, including IPS. Hence, identifying inflammatory mechanisms contributing to EC damage and strategies to protect EC integrity and function have significant merit. We have demonstrated that TNFα contributes directly to EC injury and regulates the chemokine milieu and influx of donor cells into the lung. Laboratory insights led to clinical trials of TNFα inhibition for IPS. Many, but not all, patients with IPS respond to TNFα inhibition, underscoring the need for continued research. Results Analysis of the plasma proteome from samples derived from 3 clinical studies revealed that compared to unaffected BMT controls, patients with IPS showed marked elevations in the expression of signature cytokines, including TNFα and MCP-1. Elevated expression of molecules associated with EC injury, angiopoietin (Ang)-2, VCAM-1, and E-selectin, was also noted. Ang-2 has been shown to destabilize and further sensitize ECs to the effects of TNFα, causing enhanced expression of E- and P-selectin. Serum Ang-2 levels were elevated during IPS and correlated with response to anti-TNFα therapy. In an acute lung injury (ALI) model, IV injection of LPS to naive B6 mice results in enhanced mRNA expression of TNFα, IL-6, Ang-2, E-, and P-selectin in whole lung homogenates, and the expression of Ang-2 is regulated in part by TNFα and IL-6. EC activation was associated with increased BALF total protein and cellularity. Similar findings were noted in alloBMT mice with IPS. We hypothesized that strategies to maintain EC integrity would reduce the severity of ALI and IPS. Defibrotide (DF) is FDA approved for the treatment of BMT patients with VOD and evidence of renal or pulmonary injury. DF is believed to stabilize activated ECs and protect them from further injury. The administration of DF (50 mg/kg) IV before and after LPS injection significantly reduced mRNA expression of TNFα, IL6, Ang-2, E-, and P-selectin compared to controls. BALF showed decreased cellularity, reflecting less EC damage and leak. AlloBMT mice were treated from day -1 through day 14 with DF ip (at a dose comparable to IV) either QD or BID, and lungs were harvested from D18 to 21. Compared to controls, DF treatment reduced mRNA expression of TNFα, IL6, Ang-2, E-, and P- selectin, BALF cellularity and protein content, and lung pathology score. Conclusion The administration of DF modulates EC injury in models of ALI and IPS. Combining cytokine inhibition with agents that stabilize EC integrity may represent a novel therapeutic strategy for patients with IPS.

Novel functions of grass carp three p40 isoforms as modulators of Th17 signature cytokine expression in head kidney leukocytes

Interleukin (IL)-12p40, a component of IL-12 and IL-23, can be secreted as monomer and homodimer in mammals. Our previous study has proved the existence of natural three p40 isoforms and their proinflammatory properties in grass carp. In the present study, we unexpectedly found that recombinant grass carp p40a/b/c (rgcp40a, rgcp40b and rgcp40c) were able to enhance the mRNA levels of grass carp il-17a/f1 (gcil-17a/f1) in a dose- and time-dependent manner in head kidney leukocytes (HKLs). In agreement with these findings, the enzyme-linked immunosorbent assay (ELISA) showed that rgcp40a, rgcp40b and rgcp40c markedly stimulated gcIl-17a/f1 secretion from the HKLs. Together with their stimulatory effects on grass carp gcil-22 and gcil-26 expression, our data suggested their potential to mediate Th17-like response in grass carp. To support this notion, we investigated the underlying mechanisms for the regulation of rgcp40 isoforms on gcil-17a/f1 expression, and found that three rgcp40 isoforms significantly induced the activation of Erk, Jnk and Stat3 pathways in a time-dependent oscillation in the same cell model. Moreover, three rgcp40 isoforms-induced gcil-17a/f1 mRNA expression was suppressed by the inhibition on Erk, Jnk and Stat3 pathways, suggesting the signaling pathways in the p40 isoforms-mediating il-17a/f1 transcription. These studies for the first time proved the involvement of three gcp40 isoforms in mediating Th17 signature cytokine expression in fish immune cells, therefore providing new insights into the roles of p40 in teleost immunity.

Subsets of ILC3-ILC1-like cells generate a diversity spectrum of innate lymphoid cells in human mucosal tissues.

Innate lymphoid cells (ILCs) are tissue-resident lymphocytes categorized on the basis of their core regulatory programs and the expression of signature cytokines. Human ILC3s that produce the cytokine interleukin-22 convert into ILC1-like cells that produce interferon-γ in vitro, but whether this conversion occurs in vivo remains unclear. In the present study we found that ILC3s and ILC1s in human tonsils represented the ends of a spectrum that included additional discrete subsets. RNA velocity analysis identified an intermediate ILC3-ILC1 cluster, which had strong directionality toward ILC1s. In humanized mice, the acquisition of ILC1 features by ILC3s showed tissue dependency. Chromatin studies indicated that the transcription factors Aiolos and T-bet cooperated to repress regulatory elements active in ILC3s. A transitional ILC3-ILC1 population was also detected in the human intestine. We conclude that ILC3s undergo conversion into ILC1-like cells in human tissues in vivo, and that tissue factors and Aiolos were required for this process.

Functional characterization of three fish-specific interleukin-23 isoforms as regulators of Th17 signature cytokine expression in grass carp head kidney leukocytes

Mammalian Interleukin (IL)-23 is a heterodimeric cytokine with an IL-23-specific P19 subunit and a P40 subunit shared with IL-12, and plays a key role in the regulation of cell differentiation as well as inflammation. We previously demonstrated the existence of three soluble fish Interleukin (Il)-23 isoforms consist of a single P19 and one of three P40 isoforms (P40a/b/c) in grass carp. In the present study, three recombinant grass carp Il-23 (rgcIl-23) isoforms were prepared by linking gcP19 and gcP40a/b/c in a prokaryotic expression system, and then their functional properties were verified in grass carp head kidney leukocytes (HKLs). All three rgcIl-23 isoforms showed the bioactivities to divergently upregulate the mRNA expression of Th17 signature cytokines (il17a/f1, il21, il22 and il26) as well as Il-23 receptor (il23r) in HKLs. Moreover, they also promoted gcIl-17a/f1 secretion in a dose-dependent manner, strengthening their roles in Th17-like response. Furthermore, induction of il17a/f1 and il23r transcription by rgcIl-23 was blocked by a STAT3 inhibitor in grass carp HKLs, suggesting the involvement of STAT3 signaling in these inductions. Taken together, we for the first time identified the bioactivities of fish Il-23 isoforms and particularly revealed the existence of Il-23/Il-17a/f1 axis in fish, thereby advancing our understanding of Th17-like responses in fish immunity.

Multilayer regulation of CD4 T cell subset differentiation in the era of single cell genomics.

CD4 T cells are major immune cell types that mediate effector responses appropriate for diverse incoming threats. These cells have been categorized into different subsets based on how they are induced, expression of specific master transcription factors, and the resulting effector cell phenotypes as defined by expression of signature cytokines. However, recent studies assessing the expression of gene modules in single CD4 T cells, rather than expression of one or a few signature genes, have provided a more complex picture in which the canonical model does not fit as cleanly as proposed. Here, we review the concepts of lineage commitment, plasticity and functional heterogeneity in the context of this greater complexity. We then apply our current understanding of CD4 T cell subsets to discuss outstanding questions regarding follicular helper T cells and follicular regulatory T cells with respect to their shared features with other known CD4 T cell subsets.

Molecular detection of uterine innate lymphoid cells in the immunological mouse model of pregnancy loss

Innate lymphoid cells (ILCs) are newly identified members of the innate lymphocyte family, which can function as adaptive T cells and act as critical modulators of inflammatory processes within different tissues and immune diseases. The role of uterine ILCs (uILCs) has recently been elucidated alongside changes associated with normal pregnancy. However, the proportions of uterine ILCs and their role in unsuccessful pregnancy remain unclear. We analyzed the characterization of uILC subsets and the expression of signature cytokines associated with ILCs in a mouse model of unsuccessful pregnancy induced by LPS, and we describe the dynamic changes they undergo during this process. We found that mice exposed to LPS display significantly higher levels of uNK cells, and uILC3s. However, a lower proportion of uILC2s and uILC1s were detected in abortion mice. In addition, we found that abortion mice display markedly higher expression of IFN-γ and IL-A17, and lower levels of IL-5. No significant differences in the expression of IL-13 and IL-22 were observed. The findings suggest that uILCs play distinct non-redundant roles during pregnancy, and uILCs may affect maternal-fetal tolerance via IL-17A, IL-5, and IFN-γ production.

Role of γ-glutamyltranspeptidase in the pathogenesis of Helicobacter suis and Helicobacter pylori infections.

Helicobacter (H.) suis can colonize the stomach of pigs as well as humans, causing chronic gastritis and other gastric pathological changes including gastric ulceration and mucosa-associated lymphoid tissue (MALT) lymphoma. Recently, a virulence factor of H. suis, γ-glutamyl transpeptidase (GGT), has been demonstrated to play an important role in the induction of human gastric epithelial cell death and modulation of lymphocyte proliferation depending on glutamine and glutathione catabolism. In the present study, the relevance of GGT in the pathogenesis of H. suis infection was studied in mouse and Mongolian gerbil models. In addition, the relative importance of H. suis GGT was compared with that of the H. pylori GGT. A significant and different contribution of the GGT of H. suis and H. pylori was seen in terms of bacterial colonization, inflammation and the evoked immune response. In contrast to H. pyloriΔggt strains, H. suisΔggt strains were capable of colonizing the stomach at levels comparable to WT strains, although they induced significantly less overall gastric inflammation in mice. This was characterized by lower numbers of T and B cells, and a lower level of epithelial cell proliferation. In general, compared to WT strain infection, ggt mutant strains of H. suis triggered lower levels of Th1 and Th17 signature cytokine expression. A pronounced upregulation of B-lymphocyte chemoattractant CXCL13 was observed, both in animals infected with WT and ggt mutant strains of H. suis. Interestingly, H. suis GGT was shown to affect the glutamine metabolism of gastric epithelium through downregulation of the glutamine transporter ASCT2.Electronic supplementary materialThe online version of this article (doi:10.1186/s13567-015-0163-6) contains supplementary material, which is available to authorized users.

Engineered FVIII-Specific Human T-Effector Cells: Can the T-Cell Receptor Modulate CD4+ T-Helper Phenotypes or Is It Just a “Switch”?

Abstract Engineered T cells are a vital component in the armamentarium of cellular therapies. In this presentation, we examine how human CD4+ T cells, genetically engineered to express a T-cell receptor (TCR) specific for a C2 domain epitope of the coagulation protein cofactor FVIII, can be skewed or polarized to different T-helper subsets. Two TCRs were cloned from Th2 and Th17/Th1 phenotyped CD4+ T cells isolated via a tetramer guided epitope mapping (TGEM) technique from a hemophilia A subject after clinical diagnosis of an inhibitor (neutralizing antibody) to FVIII given as replacement therapy. The two TCRs were cloned using a 5’ RACE with semi-nested PCR and transduced via a retroviral vector into healthy non-hemophilia A human donor CD4+ T cells. Based on proliferation and HLA class II tetramer staining data, engineered CD4+ T cells expressing the different cloned TCRs exhibited different avidities for the same C2 peptide (containing the epitope) over a dose titration curve, despite similar levels of TCR expression on the CD4 T-cell surface. IFN-γ, TNF-α, IL-6, and IL-10 cytokine production levels following stimulation with C2 peptide and DR1 antigen presenting cells, as measured by cytokine bead analysis, were significantly greater for the higher avidity TCR, which was cloned from a “Th2” phenotyped CD4+ T-cell clone. Interestingly, neither the engineered CD4+ T cells expressing the Th2 TCR nor the cells expressing the Th17/Th1 TCR produced cytokines characteristic of their respective original parental clones. Rather, they reflected the cytokine profiles of the donor populations used for transduction. These preliminary data led us to investigate how the different avidities of the two cloned TCRs can modulate the T-helper subset skewing/differentiation potential of engineered CD4+T cells. We hypothesized that the TCR is merely a switch that can activate or direct engineered CD4+ T cells to an antigen-specific response that would be skewed to the T-helper phenotypes of the cells prior to TCR transduction. We further hypothesized that this response could be modulated after TCR transduction according to the apparent tetramer avidity of the engineered cells. We successfully skewed the engineered human T-helper cells to Th1, Th2 and Th17 lineages, based on T-helper signature cytokine expression and the transcription factors T-bet, Gata3 and RORγt. Moreover, we observed that TCR transduction into naïve human CD4+ T cells did not itself affect the T-helper subset skewing of the cells. Preliminary experiments showed a trend toward Th2 skewing for the high avidity Th2 CD4+ T cells having an engineered TCR when they were cultured under either Th1 or Th2 polarizing conditions and stimulated with the C2 peptide, compared to the phenotypes obtained following stimulation of polyclonal CD4 T cells with anti-CD3. These studies will improve our designing of engineered TCRs for CD4+T-cell therapy, especially when concerns of T-helper effector function and plasticity are important to clinical outcomes. Supported by NIH RO1-HL061883 (DWS), funding from Bayer and CSL Behring (KPP) and intramural support from NIAID (EMS). We thank Dr. Arthur Thompson (Puget Sound Blood Center) for enrolling patients and we thank all blood donors. Disclosures No relevant conflicts of interest to declare.

Defining Th-cell subsets in a classical and tissue-specific manner: Examples from the skin.

Th cells are important mediators of adaptive immunity and involved in various diseases. During the past decade, the Th family has expanded from including Th1 and Th2 cells to also encompass Th9, Th17, Th22, and Treg cells; the original classification using the expression of signature cytokines is still the gold standard for definition of subset affiliation. However, the identification of Th cells that do not fit into these tight conceptual boundaries has tumbled the field into an identity crisis. This review gives an overview on different Th-cell classification approaches, their advantages and drawbacks. In addition, this review highlights the functional properties of distinct Th subsets and their effector cytokines in tissues and disease-specific settings with a special focus on inflammatory skin diseases.

Transcription factor interplay in T helper cell differentiation

The differentiation of CD4 helper T cells into specialized effector lineages has provided a powerful model for understanding immune cell differentiation. Distinct lineages have been defined by differential expression of signature cytokines and the lineage-specifying transcription factors necessary and sufficient for their production. The traditional paradigm of differentiation towards Th1 and Th2 subtypes driven by T-bet and GATA3, respectively, has been extended to incorporate additional T cell lineages and transcriptional regulators. Technological advances have expanded our view of these lineage-specifying transcription factors to the whole genome and revealed unexpected interplay between them. From these data, it is becoming clear that lineage specification is more complex and plastic than previous models might have suggested. Here, we present an overview of the different forms of transcription factor interplay that have been identified and how T cell phenotypes arise as a product of this interplay within complex regulatory networks. We also suggest experimental strategies that will provide further insight into the mechanisms that underlie T cell lineage specification and plasticity.

Gene expression of selected signature cytokines of T cell subsets in duodenal tissues of dogs with and without inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common cause of chronic diarrhoea in dogs. In people, specific cytokine patterns attributed to T cell subsets, especially T helper cell [Th]1, Th17 and regulatory T(reg) cells have emerged in IBD. In contrast, no specific involvement of a distinct T cell subset has been described so far in canine IBD. Thus, the aim of the present study was to assess gene expression of signature cytokines in duodenal tissues from 18 German shepherd dogs with IBD (group 1), 33 dogs of other breeds with IBD (group 2) and 15 control dogs (group 3). Relative quantification of IL-17A, IL-22, IL-10, IFNy and TGFβ was performed. Expression of IL-17A was significantly lower in groups 1 and 2 compared to group 3 (p=0.014), but no difference in the expression of IL-22 (p=0.839), IFNγ (p=0.359), IL-10 (p=0.085) or TGFβ (p=0.551) across groups was detected. Thus, no clear evidence for the involvement of Th-17 signature cytokines in canine IBD at the mRNA level could be shown. The contribution of specific T cell subsets to the pathogenesis of canine IBD warrants further investigation.

Molecular mechanisms by which T‐bet regulates T‐helper cell commitment

Current research suggests that a number of newly identified T-helper cell subsets retain a degree of context-dependent plasticity in their signature cytokine expression patterns. To understand this process, a major challenge is to determine the molecular mechanisms by which lineage-defining transcription factors regulate gene expression profiles in T-helper cells. This mechanistic information will aid in our interpretation of whether a T-helper cell state that expresses or retains the capacity to re-express a combination of lineage-defining transcription factors will have a stable or more flexible gene expression profile. Studies examining the developmental T-box transcription factor T-bet demonstrate the powerful information that is gained from combining in vivo analysis with basic biochemical and molecular mechanism approaches. Significantly, T-bet's ability to physically recruit epigenetic modifying complexes, in particular a Jmjd3 H3K27-demethylase and a Set7/9 H3K4-methyltransferase complex, to its target genes allows T-bet to effectively reverse and establish new epigenetic states. This observation suggests that until T-bet is permanently extinguished, T-helper cells will retain some plasticity toward a T-helper 1-like program. Therefore, insight into the complexity of T-helper cell commitment decisions will be aided by determining the molecular mechanisms for lineage-defining transcription factors.

OR.38. Following Interaction with TIM-4, Regulatory T Cells Lack Immunoregulatory Function

Effector CD4 T cell lineages have been implicated as potent inducers of autoimmune diseases. Tbet, Gata3 and Rorgt are master transcriptional regulators of Th1, Th2 and Th17 lineages respectively and promote the distinct expression of signature cytokines. Significant progress has been made in understanding the transcriptional network that drives CD4 T cell differentiation, revealing novel points of regulation mediated by transcription factors, cell surface receptors, cytokines and chemokines. Epigenetic modifications and metabolic mediators define the transcriptional landscape in which master transcription factors operate and collaborate with a network of transcriptional modifiers to guide lineage specification, plasticity and function.

Transcriptional Activators of Helper T Cell Fate Are Required for Establishment but Not Maintenance of Signature Cytokine Expression

The stability of helper T cell fates is not well understood. Using conditional introduction of dominant-negative factors, we now show that T-bet and GATA-3 are far more critical in establishment than maintenance of IFN-gamma and IL-4 activity during Th1 and Th2 maturation, respectively. We also show that a genetic interaction between T-bet and its target Hlx seems to be required for Th1 maturation, but that Hlx may also be dispensable for maintenance of a transcriptionally permissive ifng gene. In parallel to progressive activator independence in the permissive lineage, the ifng gene becomes more recalcitrant to switching as the forbidden lineage matures. T-bet plus Hlx can disrupt ifng silencing when introduced into developing Th2 cells, but they fail to perturb ifng silencing in mature Th2 cells. In contrast, a hypermorphic allele of T-bet can reverse silencing of the ifng gene in mature Th2 cells. These results suggest that signature gene activity of helper T cells is initially plastic but later becomes epigenetically fixed and offer an initial strategy for inducing mature cells to switch their fate.

The Role of T Lymphocytes in the Pathogenesis of Kawasaki Disease in an Animal Model

Kawasaki disease (KD) is the most common cause of multisystem vasculitis in children in the developed world. Although KD is widely believed to be the result of an infectious agent, its etiology is still unknown. Past research has reported the possible role for bacterial superantigens in the induction of KD. Our laboratory has characterized a novel superantigen found in Lactobacillus casei cell wall extract (LCWE) which is responsible for triggering the immune response leading to KD-like coronary vasculitis in injected mice. In this study, we investigated the T helper subsets responsible for disease induction by studying expression of signature cytokines. LCWE was injected into susceptible mouse strains and RT-PCR, flow cytometry, and immunohistochemistry were performed on peripheral lymphoid tissue at set time-points. Expression and production of T helper subset associated cytokines were determined. Cardiac tissue was also similarly analyzed to determine the relationship between the immune response in the periphery to that in the heart end organ. Semi-quantitation of cytokine mRNA expression demonstrated a Th1 predominated phenotype in the periphery at days 1 to 3 post LCWE injection (IFNγ). This was followed by Th2 cytokine upregulation after day 3 (IL-4). Flow cytometry confirmed this finding by the detection of intracytoplasmic IFNγ and IL-4 at similar relative timepoints. In the heart end organ, IFNγ expression was found to be abnormally upregulated 42 days after LCWE injection. Infiltrates identified as T lymphocytes were seen as early as 3 days post LCWE injection and observed in all latter time points (up to 6 months). Different T lymphocyte subsets, at different times, are able to mediate the immunologic responses leading to inflammation. Dissecting this immune response to LCWE in mice gives important clues to the etiology of Kawasaki disease in humans.