Maintenance Of CD8 Research Articles

Guselkumab Efficacy after Withdrawal Is Associated with Suppression of Serum IL-23-Regulated IL-17 and IL-22 in Psoriasis: VOYAGE 2 Study

Guselkumab selectively inhibits IL-23 and in psoriasis, produces high clinical responses, including durable maintenance after treatment withdrawal in some patients. The relationships between IL-23 blockade, serum markers downstream of IL-23 signaling, and withdrawal were explored with guselkumab in VOYAGE2. At week 28, patients with ≥90% Psoriasis Area and Severity Index improvement from baseline (PASI 90) were rerandomized to withdrawal and received placebo (n= 182), or maintenance therapy (n= 193). The guselkumab withdrawal group reinitiated guselkumab upon loss of ≥50% of week- 28 PASI improvement or by week 72. Cytokine changes associated with psoriasis recurrence (serum IL-17A, IL-17F, IL-22, and IL-23) after withdrawal were evaluated. Efficacy in the guselkumab maintenance group was sustained through week 72, whereas efficacy diminished in the guselkumab withdrawal group (PASI 90, 86.0% vs. 11.5%). After 20 weeks of retreatment, 80.4% of guselkumab withdrawal patients achieved PASI 90 responses versus baseline. Maintenance of response after withdrawal was associated with suppression of IL-17A, IL-17F, and IL-22. Increases in cytokine levels had poor predictive power for psoriasis reoccurrence as these increases lagged behind increases in PASI scores. Upon guselkumab withdrawal, most patients lost clinical response and regained responses with retreatment. Correlation of IL-23 signaling serum cytokines increased with disease recurrence, supporting the role of IL-23 in expansion and maintenance of CD4+ T helper type 17, T helper type 22, and related CD8+ T-cell subsets producing IL-17A, IL-17F, and IL-22.

Acylglycerol Kinase Maintains Metabolic State and Immune Responses of CD8+ T Cells

CD8+ Tcell expansions and functions rely on glycolysis, but the mechanisms underlying CD8+ Tcell glycolytic metabolism remain elusive. Here, we show that acylglycerol kinase (AGK) is required for the establishment and maintenance of CD8+ Tcell metabolic and functional fitness. AGK deficiency dampens CD8+ Tcell antitumor functions invivo and perturbs CD8+ Tcell proliferation invitro. Activation of phosphatidylinositol-3-OH kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling, which mediates elevated CD8+ Tcell glycolysis, is tightly dependent on AGK kinase activity. Mechanistically, Tcell antigen receptor (TCR)- and CD28-stimulated recruitment of PTEN to the plasma membrane facilitates AGK-PTEN interaction and AGK-triggered PTEN phosphorylation, thereby restricting PTEN phosphatase activity in CD8+ Tcells. Collectively, these results demonstrate that AGK maintains CD8+ Tcell metabolic and functional state by restraining PTEN activity and highlight a critical role for AGK in CD8+ Tcell metabolic programming and effector function.

Peripheral and systemic antigens elicit an expandable pool of resident memory CD8+ T cells in the bone marrow.

BM has been put forward as a major reservoir for memory CD8+ T cells. In order to fulfill that function, BM should “store” memory CD8+ T cells, which in biological terms would require these “stored” memory cells to be in disequilibrium with the circulatory pool. This issue is a matter of ongoing debate. Here, we unequivocally demonstrate that murine and human BM harbors a population of tissue‐resident memory CD8+ T (TRM) cells. These cells develop against various pathogens, independently of BM infection or local antigen recognition. BM CD8+ TRM cells share a transcriptional program with resident lymphoid cells in other tissues; they are polyfunctional cytokine producers and dependent on IL‐15, Blimp‐1, and Hobit. CD8+ TRM cells reside in the BM parenchyma, but are in close contact with the circulation. Moreover, this pool of resident T cells is not size‐restricted and expands upon peripheral antigenic re‐challenge. This works extends the role of the BM in the maintenance of CD8+ T cell memory to include the preservation of an expandable reservoir of functional, non‐recirculating memory CD8+ T cells, which develop in response to a large variety of peripheral antigens.

CD28 Signaling Controls Metabolic Fitness of Pathogenic T Cells in Medium and Large Vessel Vasculitis

BackgroundIn giant cell arteritis, vessel-wall infiltrating CD4 T cells and macrophages form tissue-destructive granulomatous infiltrates, and the artery responds with a maladaptive response to injury, leading to intramural neoangiogenesis, intimal hyperplasia, and luminal occlusion. Lesion-residing T cells receive local signals, which represent potential therapeutic targets. ObjectivesThe authors examined how CD28 signaling affects vasculitis induction and maintenance, and which pathogenic processes rely on CD28-mediated T-cell activation. MethodsVasculitis was induced by transferring peripheral blood mononuclear cells from giant cell arteritis patients into immunodeficient NSG mice engrafted with human arteries. Human artery–NSG chimeras were treated with anti-CD28 domain antibody or control antibody. Treatment effects and immunosuppressive mechanisms were examined in vivo and in vitro applying tissue transcriptome analysis, immunohistochemistry, flow cytometry, and immunometabolic analysis. ResultsBlocking CD28-dependent signaling markedly reduced tissue-infiltrating T cells and effectively suppressed vasculitis. Mechanistic studies implicated CD28 in activating AKT signaling, T-cell proliferation and differentiation of IFN-γ and IL-21–producing effector T cells. Blocking CD28 was immunosuppressive by disrupting T-cell metabolic fitness; specifically, the ability to utilize glucose. Expression of the glucose transporter Glut1 and of glycolytic enzymes as well as mitochondrial oxygen consumption were all highly sensitive to CD28 blockade. Also, induction and maintenance of CD4+CD103+ tissue-resident memory T cells, needed to replenish the vasculitic infiltrates, depended on CD28 signaling. CD28 blockade effectively suppressed vasculitis-associated remodeling of the vessel wall. ConclusionsCD28 stimulation provides a metabolic signal required for pathogenic effector functions in medium and large vessel vasculitis. Disease-associated glycolytic activity in wall-residing T-cell populations can be therapeutically targeted by blocking CD28 signaling.

MiR155 sensitized B-lymphoma cells to anti-PD-L1 antibody via PD-1/PD-L1-mediated lymphoma cell interaction with CD8+T cells

BackgroundMicroRNAs (miRs) are involved in lymphoma progression by regulating tumor cell interaction with microenvironment. MiR155 is overexpressed in diffuse large B-cell lymphoma (DLBCL) and its biological effect on tumor microenvironment needs to be futher investigated.MethodsMiR155 was detected by quantitative real-time PCR in patients with newly diagnosed DLBCL. The mechanism of action of miR155 on lymphoma progression and tumor microenvironment was examined in vitro in B-lymphoma cell lines and in vivo in a murine xenograft model.ResultsSerum miR155 was significantly elevated, correlated with tumor miR155 expression, and indicated poor disease outcome in DLBCL. MiR155 overexpression was associated with decreased peripheral blood CD8+T cells and inhibition of T-cell receptor signaling. Of note, EBV-positive patients showed higher serum miR155 than EBV-negative patients. In co-culture systems of B-lymphoma cells with immune cells, miR155 induced Fas-mediated apoptosis of CD8+T cells, which could be targeted by anti-PD-1 and anti-PD-L1 antibodies. Moreover, miR155 enhanced lymphoma cell PD-L1 expression, recruited CD8+T cells by PD-1/PD-L1 interaction and inhibited CD8+T cell function via dephosphorylating AKT and ERK. MiR155-induced AKT/ERK inactivation was more obvious in CD8+T cells co-cultured with EBV-infected B-lymphoma cells. In vivo in a murine xenograft model established with subcutaneous injection of A20 cells, PD-L1 blockade particularly retarded miR155-overexpressing tumor growth, consistent with maintenance of CD8+T cells and their function.ConclusionsAs a oncogenic biomarker of B-cell lymphoma, serum miR155 was related to lymphoma progression through modulating PD-1/PD-L1-mediated interaction with CD8+T cells of tumor microenvironment, indicating the sensitivity of B-cell lymphoma to PD-L1 blockade. Also CD8+T cells could be a therapeutic mediator of immune checkpoint inhibitors in treating EBV-associated lymphoid malignancies.

Abstract B173: G protein coupling signaling as regulators of dendritic cell maintenance and function in immune responses

Abstract Dendritic cells (DCs) are well known as the professional antigen presenT-cells (APCs), which can scan peripheral tissues where they can recognize, uptake, process and present all kinds of antigens, including pathogens and tumor antigens, to antigen specific naïve T-cells within the lymphoid organs. In these processes, DCs form a remarkable bridge between innate and adaptive immunity by interacting with various lymphoid and myeloid cells. DCs originate from the bone marrow hematopoietic progenitor cells and DC precursors migrate from blood to tissues for developing into immature DCs. Upon activation, DCs migrate to stimulate T-cells and induce immune responses to protect our bodies. However, the mechanism for maintenance and activation of DCs on the local microenvironment is largely unknown. As GPCR signaling has important roles in many cellular process, including cell division, survival, migration and adhesion. Using competitive mixed BM chimaera, I checked some molecules involved in GPCR signal pathways, and found that geneA was required intrinsically in the maintenance of CD4+ conventional DCs (cDCs) in the spleen, as evidenced by observation that geneA-deficient CD4+ DCs were dramatically decreased in spleen but increased in blood. By in vivo 3min CD45-PE labeling assay, cells exposed to the vascular compartment in spleen can be selectively labeled. With this method, I found without geneA, CD4+ DCs had disadvantage to be maintained in the blood-exposed region within the spleens under the shear flow stress. I further showed that geneA-deficient CD4+ DCs had disadvantage to uptake blood-derived Sheep-blood cells (SRBCs). Besides this stimulation, this signal also controlled CD4+ DCs activation in response to different kinds of TLR stimulators. By OT-II adoptive transfer system, geneA-expressing DCs were required to support T-cell proliferation and differentiation efficiently. Therefore, these results demonstrate a key role of G protein-coupled receptor signaling in promoting the maintenance and activation of DCs, and reveal a mechanism in DC positioning in vivo. Thus, it will broaden our understanding of GPCR signaling in DC immunology, which is pivotal for modulating DCs for vaccines and therapies against pathogens, autoimmune diseases and tumors. Citation Format: Dan Liu, Jason G. Cyster. G protein coupling signaling as regulators of dendritic cell maintenance and function in immune responses [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B173.

IMMUNOLOGICAL MEMORY: THE ROLE OF REGULATORY CELLS (TREGS)

Memory T cells are necessary for development of the immune response and represent one of the most numerous population of human T lymphocytes. On the contrary, suppressive regulatory T cells (Tregs) may terminate the immune response and help to maintain tolerance to self-antigens. These important groups of cells are consisting of different subpopulations and retaining throughout life. However, today there is yet no clear understanding of how the relations between these two groups of cells are formed. In this work we consider possible ways of development and maintenance of CD4+ T cell memory and role of Tregs in these processes. Mechanisms of a differentiation of memory T cells, Tregs and recently described memory Tregs are discussed. The functional and genetic characteristics of these cells are compared. Division of cells according to the functional profile allows drawing parallels between memory T cells and Tregs. These two groups are consisted of central circulating populations (Tc), effector which can migrate toward specific tissues (Te) and tissue-resident cells (Tr), which are staying in peripheral tissues. The similar structural organization of Tregs and memory T cells, existence of transitional forms of tissue-resident Treg subpopulations with properties of memory cells assumes existence of close interrelation between these groups of lymphocytes. The conversion of CD4+ memory T cells into FoxP3-expressing Tregs is one of possible mechanisms of communication between these two groups. The memory Treg-cells with T cell and memory Treg-cell properties can represent a transitional stage of differentiation. On the other side, Treg cells can differentiate independently of memory T cells and accumulate during life in the form of memory Treg cells. The supressor function of Tregs is also necessary as well as function of memory T cells to develop the immune response. It is possible, that a subset of Treg cells undergoes selection in thymus and constitutively express TCR-receptors having affinity with peripheral tissues. Further, these committed cells can be settled into tissues and become tissue-resident Treg cells which maintain regional T cell memory. Tregs can represent the “mirror image” of the structural organization of memory T cells, but with the return sign – the sign of suppression. The quantitative ratio of Tregs and memory T cells (CD4+CD45RO+CD25hiFoxP3+/CD4+CD45RO+CD25-FoxP3-), perhaps, is important criterion for functional assessment of immune system. The balance between these functionally opposite cell subsets has to provide stable functioning of immune system.

Requirement for POH1 in differentiation and maintenance of regulatory T cells.

Foxp3-expressing regulatory T (Treg) cells are essential for averting autoimmune diseases and maintaining immune homeostasis. However, the molecular mechanisms underlying the development and maintenance of Treg cells are still unclear. Here, we found that T cell-specific deletion of the gene encoding the deubiquitinase POH1 compromised the development of mature T cells, especially CD4+Foxp3+ Treg cells. Moreover, POH1 deficiency significantly attenuated the transition of CD25+ Treg cell precursors into Foxp3+ Treg cells accompanied by downregulation of interleukin 2 (IL-2)-STAT5 signaling. Deletion of POH1 in generated CD4+Foxp3+ Treg cells led to an early onset of fetal autoimmune disorders and a decrease in the pool size of peripheral Treg cells in mice, which were mostly due to decreased expansion of these cells. Thus, these results revealed that POH1 has a pivotal role in the development and maintenance of CD4+Foxp3+ Treg cells and contributes to immune tolerance.

Maintenance of CD4 T cell fitness through regulation of Foxo1.

Foxo transcription factors play an essential role in regulating specialized lymphocyte functions and in maintaining T cell quiescence. Here, we used a system in which Foxo1 transcription-factor activity, which is normally terminated upon cell activation, cannot be silenced, and we show that enforcing Foxo1 activity disrupts homeostasis of CD4 conventional and regulatory T cells. Despite limiting cell metabolism, continued Foxo1 activity is associated with increased activation of the kinase Akt and a cell-intrinsic proliferative advantage; however, survival and cell division are decreased in a competitive setting or growth-factor-limiting conditions. Via control of expression of the transcription factor Myc and the IL-2 receptor β-chain, termination of Foxo1 signaling couples the increase in cellular cholesterol to biomass accumulation after activation, thereby facilitating immunological synapse formation and mTORC1 activity. These data reveal that Foxo1 regulates the integration of metabolic and mitogenic signals essential for T cell competitive fitness and the coordination of cell growth with cell division.

Past Life and Future Effects-How Heterologous Infections Alter Immunity to Influenza Viruses.

Influenza virus frequently mutates due to its error-prone polymerase. This feature contributes to influenza virus’s ability to evade pre-existing immunity, leading to annual epidemics and periodic pandemics. T cell memory plays a key protective role in the face of an antigenically distinct influenza virus strain because T cell targets are often derived from conserved internal proteins, whereas humoral immunity targets are often sites of increased mutation rates that are tolerated by the virus. Most studies of influenza T cell memory are conducted in naive, specific pathogen free mice and do not account for repetitive influenza infection throughout a lifetime, sequential acute heterologous infections between influenza infections, or heterologous chronic co-infections. By contrast to these mouse models, humans often experience numerous influenza infections, encounter heterologous acute infections between influenza infections, and are infected with at least one chronic virus. In this review, we discuss recent advances in understanding the effects of heterologous infections on the establishment and maintenance of CD8+ T cell immunological memory. Understanding the various factors that affect immune memory can provide insights into the development of more effective vaccines and increase reproducibility of translational studies between animal models and clinical results.

Defining the role of CD69 in the formation of resident memory CD8+ T cells

Abstract Resident memory CD8+ T cells (TRM) reside in nonlymphoid tissues. There, they play a key role in preventing reinfection by exerting cytotoxic and inflammatory functions upon exposure to previously encountered pathogens. CD69 is often used as a definitive marker of TRM cells. CD69’s interaction with the G-protein-coupled receptor S1PR1 has been identified as one mechanism by which CD69 can regulate tissue residency. However, the functional requirement for CD69 in promoting the generation and maintenance of CD8+ TRM under a wide variety of circumstances remains unclear. We explored the role of CD69 in tissue residency using co-transfer of antigen specific CD69 sufficient and deficient CD8+ T cells in the context of acute LCMV, Influenza, and VSV infections. Strikingly, we found that CD69 was not necessary for TRM establishment in most tissues, although it can promote TRM localization under some circumstances. This seems to be influenced by the focal point of infection. Interestingly, the kidney appears to rely on CD69 for tissue residency with every model pathogen examined. We propose that the requirement for CD69 is context dependent rather than absolute, and that a combination of factors, including tissue microenvironment and infectious agent, dictate CD69’s influence on development of CD8+ resident memory.

The function and dysfunction of memory CD8+ T cells in tumor immunity.

The generation and maintenance of CD8+ T cell memory is crucial to long-term host survival, yet the basic tenets of CD8+ T cell immunity are still being established. Recent work has led to the discovery of tissue-resident memory cells and refined our understanding of the transcriptional and epigenetic basis of CD8+ T cell differentiation and dysregulation. In parallel, the unprecedented clinical success of immunotherapy has galvanized an intense, global research effort to decipher and de-repress the anti-tumor response. However, the progress of immunotherapy is at a critical juncture, since the efficacy of immuno-oncology agents remains confined to a fraction of patients and often fails to provide durable benefit. Unlocking the potential of immunotherapy requires the design of strategies that both induce a potent effector response and reliably forge stable, functional memory T cell pools capable of protecting from recurrence or relapse. It is therefore essential that basic and emerging concepts of memory T cell biology are rapidly and faithfully transposed to advance therapeutic development in cancer immunotherapy. This review highlights seminal and recent reports in CD8+ T cell memory and tumor immunology, and evaluates recent data from solid cancer specimens in the context of the key paradigms from preclinical models. We elucidate the potential significance of circulating effector cells poised downstream of neoantigen recognition and upstream of T cell dysfunction and propose that cells in this immunological 'sweet spot' may be key anti-tumor effectors.

Evaluation of immune responses induced by a novel human papillomavirus type 16 E7 peptide-based vaccine with Candida skin test reagent as an adjuvant in C57BL/6 mice

Cell mediated immune (CMI) responses are crucial for the clearance of human papillomavirus (HPV) infection and HPV-associated lesions. Activated CD8 T cells are critical effector cells in recognizing and killing HPV-infected or HPV-transformed cells. CD4 T cells provide help for priming the generation and maintenance of CD8 T cells as well as for tumors immunity. An ideal therapeutic HPV peptide-based vaccine should induce both a robust CD8 T-cell response as well as a CD4 T-cell response for ensuring their efficiency. Candida skin test reagent was demonstrated to be able to induce the secretion of IL-12 by Langerhans cells and T-cell proliferation in vitro by our group, which indicated the potential of Candida to enhance CMI response. In this current study, we designed a novel HPV peptide-based vaccine which includes HPV16 E7 peptides and Candida as an adjuvant. The immune responses induced by the vaccine were comprehensively evaluated. The results showed that the vaccine induced significant HPV-specific CD8 T-cell and Th1 CD4 T-cell responses as well as humoral immune response. It is interesting that Candida alone induced a significant polarization of Th1 response an production of IFN-γ, which indicated Candida alone may be used as a potential immunotherapeutic reagent not only for HPV-associated lesions but also for other viral infection or even cancers.

Commentary: Maintenance of CD8+ T Memory Lymphocytes in the Spleen but Not in the Bone Marrow Is Dependent on Proliferation.

Commentary: Maintenance of CD8+ T Memory Lymphocytes in the Spleen but Not in the Bone Marrow Is Dependent on Proliferation.

Downregulated IL-21 Response and T Follicular Helper Cell Exhaustion Correlate with Compromised CD8 T Cell Immunity during Chronic Toxoplasmosis.

CD8 T cells are important for maintaining the chronicity of Toxoplasma gondii infection. In a T. gondii encephalitis susceptible model, we recently demonstrated that CD4 T cells play an essential helper role in the maintenance of the effector response and CD8 T cell dysfunctionality was linked to CD4 T cell exhaustion. However, CD4 T cells are constituted of different subsets with various functions and the population(s) providing help to the CD8 T cells has not yet been determined. In the present study, T follicular helper cells (Tfh), which are known to be essential for B cell maturation and are one of the main sources of IL-21, were significantly increased during chronic toxoplasmosis. However, at week 7 p.i., when CD8 T cells are exhausted, the Tfh population exhibited increased expression of several inhibitory receptors and levels of IL-21 in the serum were decreased. The importance of IL-21 in the maintenance of CD8 T cells function after T. gondii infection was further demonstrated in IL-21R KO mouse model. Interestingly, while CD8 T cells from both knockout (KO) and wild-type mice expressed similar levels of PD-1, animals with defective IL-21 signaling exhibited lower polyfunctionality than wild-type controls. This reduced polyfunctional ability observed in CD8 T cells from KO mice was associated with a significant increase in other inhibitory receptors like Tim-3, LAG-3, and 2B4. Furthermore, the animals exhibited greater signs of Toxoplasma reactivation manifested by the reduced number of cysts and increased expression of tachyzoite (replicative form of the parasite) specific genes (SAG1 and ENO2) in the brain. Also, IL-21R KO mice displayed a higher frequency of tachyzoite-infected monocytes in the blood and spleen. Our findings suggest the importance of Tfh and IL-21 during chronic toxoplasmosis and establish a critical role for this cytokine in regulating CD8 T cell dysfunction by preventing the co-expression of multiple inhibitory receptors during chronic parasitic infection.

Maintenance of CD8+ memory T lymphocytes in the spleen but not in the bone marrow is dependent on proliferation.

It is current belief that numbers of CD8+ memory T lymphocytes in the memory phase of an immune response are maintained by homeostatic proliferation. Here, we compare the proliferation of CD8+ memory T lymphocytes, generated by natural infections and by intentional immunization, in spleen and bone marrow (BM). Fifty percent of CD8+ memory T lymphocytes in the spleen are eliminated by cyclophosphamide within 14 days, indicating that numbers of at least 50% of splenic CD8+ memory T lymphocytes are maintained by proliferation. The numbers of CD8+ memory T lymphocytes in the BM, however, were not affected by cyclophosphamide. This stability was independent of circulating CD8+ memory T cells, blocked by FTY720, showing that BM is a privileged site for the maintenance of memory T lymphocytes, as resident cells, resting in terms of proliferation.

Survivin in autoimmune diseases.

Survivin is a protein functionally important for cell division, apoptosis, and possibly, for micro-RNA biogenesis. It is an established marker of malignant cell transformation. In non-malignant conditions, the unique properties of survivin make it indispensable for homeostasis of the immune system. Indeed, it is required for the innate and adaptive immune responses, controlling differentiation and maintenance of CD4+ and CD8+ memory T-cells, and in B cell maturation. Recently, survivin has emerged as an important player in the pathogenesis of autoimmune diseases. Under the conditions of unreserved inflammation, survivin enhances antigen presentation, maintains persistence of autoreactive cells, and supports production of autoantibodies. In this context, survivin takes its place as a diagnostic and prognostic marker in rheumatoid arthritis, psoriasis, systemic sclerosis and pulmonary arterial hypertension, neuropathology and multiple sclerosis, inflammatory bowel diseases and oral lichen planus. In this review, we summarise the knowledge about non-malignant properties of survivin and focus on its engagement in cellular and molecular pathology of autoimmune diseases. The review highlights utility of survivin measures for clinical applications. It provides rational for the survivin inhibiting strategies and presents results of recent reports on survivin inhibition in modern therapies of cancers and autoimmune diseases.

Defining the role of CD69 in the formation of resident memory CD8+ T cells

Abstract Resident memory CD8+ T cells (TRM) occupy parenchymal tissues and have a well-defined role in protecting from reinfection. CD69 is often considered a definitive marker of TRM, and CD69 can regulate T cell trafficking through its interaction with the G-protein-coupled receptor S1PR1. However, the functional requirement for CD69 in controlling the generation and maintenance of CD8+ TRM is unclear. We tested this using co-transfer of CD69 sufficient and deficient P14 CD8+ T cells specific for gp33/Db in the context of acute LCMV and Flu-GP33 infections. Surprisingly, we found that CD69 was not necessary for TRM establishment in most tissues. However, we found that depending on the infectious agent, CD69 could promote TRM localization in certain sites. We propose that the requirement for CD69 is context dependent, and that a combination of factors including the tissue microenvironment and infectious agent dictate its influence on development of resident memory.

Analysis of transcription factors, microRNAs and cytokines involved in T lymphocyte differentiation in patients with tuberculosis after directly observed treatment short-course

Tuberculosis (Tb) is an infectious disease in which the immune system plays an important role. MicroRNAs are involved in the development and maintenance of CD4 + T lymphocyte subpopulations. miR-326 regulates the differentiation to Th17 cells and miR-29 correlates with the Th1 response. The aim of this study was to determine the role of microRNAs, Transcription Factors, and cytokines in Th differentiation before and after the directly observed treatment short-course (DOTS). Peripheral blood mononuclear cells and serum from Tb patients were collected at times 0 (before therapy), 2 (after the intensive phase), and 6 months (after the holding phase). The cells were cultivated in presence or absence of ESAT-6 (10 μg/ml) and CFP-10 (10 μg/ml). Transcription Factor and microRNA expressions were analyzed by qPCR and cytokine production in both serum and culture supernatant using ELISA. A decrease in Th1 response with a diminishing in the relative expression of TBET and miR-29a at 2 and 6 months after the anti-Tb therapy (p < 0.01) were found. The miR-326 levels decreased after the intensive phase of the DOTS scheme. However, subdivision of the Tb patients according to gender, showed increased levels of miR-29a and miR-155 in females after the intensive phase of the therapeutic treatment when compared to time 0 and similar increased levels of miR-326 at time 6 versus time 0. In contrast, we observed a decrease in miR-326 levels in males at 6 months when compared to before therapy (time 0). In addition, high production of IL-17 in the culture supernatant was found at 2 and 6 months (p < 0.05) while in serum IL-17 was decreased. A positive correlation between IL-17 and RORC2 at time 6 was detected (p = 0.0202, r = 0.7880). In conclusion, these data suggest a reduction in Th1 and an induction of Th17 response after the anti-Tb therapy.

Memory CD4 T cell subsets are kinetically heterogeneous and replenished from naive T cells at high levels.

Characterising the longevity of immunological memory requires establishing the rules underlying the renewal and death of peripheral T cells. However, we lack knowledge of the population structure and how self-renewal and de novo influx contribute to the maintenance of memory compartments. Here, we characterise the kinetics and structure of murine CD4 T cell memory subsets by measuring the rates of influx of new cells and using detailed timecourses of DNA labelling that also distinguish the behaviour of recently divided and quiescent cells. We find that both effector and central memory CD4 T cells comprise subpopulations with highly divergent rates of turnover, and show that inflows of new cells sourced from the naive pool strongly impact estimates of memory cell lifetimes and division rates. We also demonstrate that the maintenance of CD4 T cell memory subsets in healthy mice is unexpectedly and strikingly reliant on this replenishment.