scholarly journals The Influence of Aging and Sex Hormones on Expression of Growth Hormone-Releasing Hormone in the Human Immune System1

2001 ◽  
Vol 86 (7) ◽  
pp. 3157-3161
Author(s):  
O. Khorram ◽  
M. Garthwaite ◽  
T. Golos
Keyword(s):  
T Cells ◽  
Immune System ◽  
B Cells ◽  
Mrna Expression ◽  
Postmenopausal Women ◽  
Cell Line ◽  
Immune Cell ◽  
Hormone Replacement ◽  
Men And Women

GHRH is a neuropeptide that has also been localized to the immune system. The physiological function of GHRH in the immune system has not been elucidated. This study was conducted to determine whether immune GHRH expression is altered in certain pathological states, such as immune cell tumors, and whether gender, aging, and alterations in the sex steroid milieu influence the expression of this peptide in immune cells. Using double color flow cytometry, GHRH protein was found to be expressed in less than 2% of peripheral blood mononuclear cells (PBMC). Monocytes and B and T cells all expressed GHRH protein, although a greater percentage of T cells compared with B cells and monocytes expressed GHRH (5- to 7-fold). Semiquantitative RT-PCR was used to quantify GHRH messenger ribonucleic acid (mRNA) in PBMC and several immune cell-derived tumors. PBMC and granulocytes expressed low levels of GHRH mRNA with relatively higher levels of expression in monocytes. The tumor cell lines CEMX 174 (B/T cells), HUT 78 (T cells), WIL2-N (B cells), U937 (monocytes/macrophages), and JM 1 (pre-B cell lymphoma) all showed greater expression of GHRH mRNA relative to PBMC. However, two cell lines, CCRF-SB, a B lymphoblastoid cell line, and HL-60, a promyelocytic cell line, expressed GHRH mRNA at similar levels as PBMC. A significant decrease in the percentage of lymphocytes (CD45+ cells) expressing GHRH protein was found in age-advanced men and women compared with young men and women. This decline was noted in B cells (CD20+) and monocytes (CD14+), but not in T cells (CD3+). GHRH mRNA expression in PBMC derived from postmenopausal women was lower than that from premenopausal women. However, no differences in PBMC GHRH mRNA expression were found in young and old men. Although in older men there were fewer peripheral lymphocytes that express GHRH protein, these cells secreted significantly more GHRH in vitro than cells from postmenopausal women with no hormone replacement therapy (HRT), but similar levels as cells from women receiving HRT. PBMC from women receiving HRT secreted more GHRH in vitro than cells from women receiving no hormone replacement. This study demonstrates that the expression of immune GHRH is dynamic, and therefore likely to be regulated. Increased expression of GHRH in certain immune tumors suggests that GHRH may be mitogenic under certain conditions and therefore play a role in the pathogenesis of select immune cell tumors. Collectively, these results suggest a role for GHRH as a local immune modulator and in the pathophysiology of immunosenescence and immune cell tumors.

scholarly journals SHIP1 Inhibition As Novel Therapeutic Approach in Chronic Lymphocytic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 894-894
Author(s):  
Veronika Ecker ◽  
Martina Braun ◽  
Tanja Neumayer ◽  
Markus Muschen ◽  
Jürgen Ruland ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
B Cells ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Lymphocytic Leukemia ◽  
Bcr Signaling

Abstract Chronic lymphocytic leukemia (CLL) is one of the most common B cell malignancies in the Western world. Malignant B cells are blocked from differentiating into immunoglobulin producing-plasma cells and clonally accumulate in the spleen, lymph nodes, bone marrow and peripheral blood. CLL is characterized by immunosuppression throughout all disease stages, which is mediated by increased numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Jitschin and Braun et al., Blood 2014) and direct inhibitory effects of the malignant CLL cells on T cells (Christopoulos etal., Blood 2011). Over the past decade, significant improvement in understanding the pathogenesis of CLL has highlighted the importance of active B cell receptor (BCR) signaling. This has revealed promising targeted treatment options, including the small molecule inhibitors targeting the phosphatidylinositol-3-kinase (PI3K) signaling pathway. Idelalisib and Duvelisib are under clinical investigation for CLL treatment, however, treatment-related toxicities are limiting their application and none of these approaches are curative, highlighting the importance of functional anti-tumor immune responses in CLL for prolonged treatment efficacy. Here, we are testing a novel approach that aims to selectively target CLL B cells and simultaneously restore an appropriate immune cell function. The phosphatase SH2-domain-containing inositol 5ʹ-phosphatase 1 (SHIP1) serves as negative feedback molecule and downregulates PI3K signaling in B cells by dephosphorylating the 5`phosphate of Phosphatidylinositol (3,4,5)-trisphosphate. We hypothesize that CLL cells rely on such negative regulators for optimal survival and can only tolerate a maximum signaling level. We are therefore testing whether SHIP1 inhibition induces hypersignaling and thereby CLL cell death. Furthermore, we are investigating whether SHIP1 inhibition simultanously stimulates immune responses, as it has been shown to induce expansion of murine hematopoietic and mesenchymal stem cell compartments (Brooks et al., Stem cells 2014). 3α-Aminocholestane (3AC) is a small molecule inhibitor of SHIP1 and can be used for pharmacological inhibition. First, we investigated the expression and phosphorylation levels of SHIP1 in CLL. We found SHIP1 to be expressed at various levels in CLL peripheral blood and strongly phosphorylated compared to age-matched healthy donors. Besides, SHIP1 transcription is upregulated in lymph nodes as compared to peripheral blood, which is in line with the assumption of increased BCR signaling in secondary lymphoid organs. We then set out to investigate the consequences of SHIP1 phosphatase inhibition. Similarly, to recent findings in acute lymphoblastic leukemia (Chen et al., Nature 2015), pharmacological inhibition of SHIP1 lead to rapid cell death of CLL cells. We further investigated the mode of cell death and observed specific features of apoptosis, namely caspase 3/7 activation and phosphatidylserine exposure on the outer cell membrane. This has been tested on primary CLL patient samples and T cell leukemia/lymphoma 1 (TCL1)-driven murine CLL cells and was not observed or significantly less pronounced in other lymphoma cell lines or healthy primary B cells. To confirm the specificity of the observed effects, we genetically activated AKT with a GFP reporter in the TCL1-driven mouse model in vivo and in vitro. By tracking GFP-expressing CLL cells, we observed an initial expansion followed by rapid cell death in vitro. When we induced AKT activation in vivo, GFP+ CLL cells were not detectable in the peripheral blood, total CLL count declined upon induction and we found decreased tumor burden in the secondary lymphoid organs, particularly in the lymph nodes. In addition to the direct effects on CLL cells, we sought to investigate the impact of SHIP1 inhibition on other immune cell functions. We observed that SHIP1 inhibition lowers the activity threshold of T cells: When we stimulated a reporter cell line with suboptimal doses of anti-CD3, 3AC treatment significantly enhanced the response rate. Therefore, we propose SHIP1 as a novel interesting target in CLL. In contrast to kinase inhibition and downregulation of the BCR signaling strength, phosphatase inhibition and BCR signaling overaction provides an attractive new treatment strategy for elimination of malignant CLL cells and stimulation of immune responses. Disclosures No relevant conflicts of interest to declare.

scholarly journals Single-Cell Mass Cytometry on Peripheral Blood Identifies Immune Cell Subsets Associated with Primary Biliary Cholangitis

2020 ◽  
Author(s):  
Jin Sung Jang ◽  
Brian Juran ◽  
Kevin Y. Cunningham ◽  
Vinod K. Gupta ◽  
YoungMin Son ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
B Cells ◽  
Single Cell ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Memory B Cells ◽  
Primary Biliary Cholangitis ◽  
Mass Cytometry ◽  
Peripheral Immune System

AbstractThe relationship between Primary Biliary Cholangitis (PBC), a chronic cholestatic autoimmune liver disease, and the peripheral immune system remains to be fully understood. Herein, we performed the first mass cytometry (CyTOF)-based, immunophenotyping analysis of the peripheral immune system in PBC at single-cell resolution. CyTOF was performed on peripheral blood mononuclear cells (PBMCs) from PBC patients (n=33) and age-/sex-matched healthy controls (n=33) to obtain immune cell abundance and marker expression profiles. Hiearchical clustering methods were applied to identify immune cell types and subsets significantly associated with PBC. Subsets of gamma-delta T cells (CD3+TCRgd+), CD8+ T cells (CD3+CD8+CD161+PD1+), and memory B cells (CD3-CD19+CD20+CD24+CD27+) were found to have lower abundance in PBC than in control. In contrast, higher abundance of subsets of monocytes and naïve B cells were observed in PBC compared to control. Furthermore, several naïve B cell (CD3-CD19+CD20+CD24-CD27-) subsets were significantly higher in PBC patients with cirrhosis (indicative of late-stage disease) than in those without cirrhosis. Alternatively, subsets of CD8+CD161+ T cells and memory B cells were lower in abundance in cirrhotic relative to non-cirrhotic PBC patients. Future immunophenotyping investigations could lead to better understanding of PBC pathogenesis and progression, and also to the discovery of novel biomarkers and treatment strategies.

scholarly journals Selective B cell depletion upon intravenous infusion of replication-incompetent anti-CD19 CAR lentivirus

2020 ◽  
Author(s):  
Craig M. Rive ◽  
Eric Yung ◽  
Lisa Dreolini ◽  
Daniel J. Woodsworth ◽  
Robert A. Holt
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Wild Type ◽  
Immune Cell Subsets ◽  
Car T

AbstractAnti-CD19 CAR-T therapy for B cell malignancies has shown clinical success, but a major limitation is the logistical complexity and high cost of manufacturing autologous cell products. Direct infusion of viral gene transfer vectors to initiate in vivo CAR-T transduction, expansion and anti-tumor activity could provide an alternative, universal approach for CAR-T and related immune effector cell therapies that circumvents ex vivo cell manufacturing. To explore the potential of this approach we first evaluated human and murine CD8+ T cells transduced with VSV-G pseudotyped lentivectors carrying an anti-CD19CAR-2A-GFP transgene comprising either an FMC63 (human) or 1D3 (murine) anti-CD19 binding domain. To evaluate CD19 antigen-driven CAR-T proliferation in vitro we co-cultured transduced murine T cells with an excess of irradiated splenocytes and observed robust expansion over a 9 week period relative to control T cells transduced with a GFP transgene (mean fold expansion +/- SD: ID3-CD19CAR-GFP modified T cells, 12.2 +/- 0.09 (p < 0.001); FMC63-CD19CAR-GFP modified T cells 8.8 +/- 0.03 (p < 0.001). CAR-T cells isolated at the end of the expansion period showed potent B cell directed cytolytic activity in vitro. Next, we administered approximately 20 million replication-incompetent lentiviral particles carrying either ID3-CD19CAR-GFP, FMC63-CD19CAR-GFP, or GFP-only transgene to to wild-type C57BL/6 mice by tail vein infusion and monitored the dynamics of immune cell subsets isolated from peripheral blood at weekly intervals. We saw emergence of a persistent CAR-transduced CD3+ T cell population beginning week 3-4 that reaching a maximum of 13.5 +/- 0.58 % (mean +/- SD) and 7.8 +/- 0.76% of the peripheral blood CD3+ T cell population in mice infused with ID3-CD19CAR-GFP lentivector or FMC63-CD19CAR-GFP lentivector, respectively, followed by a rapid decline, in each case of, the B cell content of peripheral blood. Complete B cell aplasia was apparent by week 5 and was sustained until the end of the protocol (week 8). None of these changes were observed in mice infused with GFP-only control lentivector, and significant CAR positive populations were not observed within other immune cell subsets, including macrophage, natural killer, or B cells. Within the T cell compartment, CD8+ effector memory cells were the predominant CAR-positive subset. Modest weight loss of 5.5 +/- 2.97 % (mean +/- SD) observed in some animals receiving an anti-CD19CAR-GFP transgene during the protocol. These results indicate that direct IV infusion of lentiviral particles carrying an anti-CD19 CAR transgene can transduce T cells that then fully ablate endogenous B cells in wild type mice. Based on these results it may be useful to further explore, using currently available vectors, the feasibility of systemic gene therapy as a modality for CAR-T intervention.

scholarly journals Immune system development varies according to age, location, and anemia in African children

2020 ◽  
Vol 12 (529) ◽  
pp. eaaw9522 ◽  
Author(s):  
Danika L. Hill ◽  
Edward J. Carr ◽  
Tobias Rutishauser ◽  
Gemma Moncunill ◽  
Joseph J. Campo ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Immune Cell ◽  
System Development ◽  
High Titer ◽  
Geographical Location ◽  
Cell Types ◽  
Iron Bioavailability ◽  
Immune System Development

Children from low- and middle-income countries, where there is a high incidence of infectious disease, have the greatest need for the protection afforded by vaccination, but vaccines often show reduced efficacy in these populations. An improved understanding of how age, infection, nutrition, and genetics influence immune ontogeny and function is key to informing vaccine design for this at-risk population. We sought to identify factors that shape immune development in children under 5 years of age from Tanzania and Mozambique by detailed immunophenotyping of longitudinal blood samples collected during the RTS,S malaria vaccine phase 3 trial. In these cohorts, the composition of the immune system is dynamically transformed during the first years of life, and this was further influenced by geographical location, with some immune cell types showing an altered rate of development in Tanzanian children compared to Dutch children enrolled in the Generation R population–based cohort study. High-titer antibody responses to the RTS,S/AS01E vaccine were associated with an activated immune profile at the time of vaccination, including an increased frequency of antibody-secreting plasmablasts and follicular helper T cells. Anemic children had lower frequencies of recent thymic emigrant T cells, isotype-switched memory B cells, and plasmablasts; modulating iron bioavailability in vitro could recapitulate the B cell defects observed in anemic children. Our findings demonstrate that the composition of the immune system in children varies according to age, geographical location, and anemia status.

scholarly journals Hemoglobin drives inflammation and initiates antigen spread and nephritis in lupus

2020 ◽  
Author(s):  
Hritika Sharma ◽  
Anjali Bose ◽  
Uma Kumar ◽  
Rahul Pal
Keyword(s):  
T Cells ◽  
B Cells ◽  
Inflammatory Cytokines ◽  
Lupus Erythematosus ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Peripheral Blood Mononuclear ◽  
Autoantibody Production

AbstractHemoglobin (Hb) has well-documented inflammatory effects and is normally efficiently scavenged; clearance mechanisms can be overwhelmed during conditions of erythrocyte lysis, a condition that may occur in systemic lupus erythematosus. Whether Hb is preferentially inflammatory in lupus and additionally induces autoreactivity against prominent autoantigens was assessed. Peripheral blood mononuclear cells derived from SLE patients secreted higher levels of lupus-associated inflammatory cytokines when incubated with Hb, effects negated by haptoglobin. Hb (more particularly, ferric Hb) triggered the preferential release of lupus-associated cytokines from splenocytes, B cells, CD4 T cells, CD8 T cells and plasmacytoid dendritic cells isolated from aging NZM2410 mice, and also had mitogenic effects on B cells. Ferric Hb activated multiple signaling pathways which were differentially responsible for the generation of specific cytokines; inflammatory signaling also appeared to be cell-context dependent. Pull-downs, followed by mass spectrometry, revealed interactions of Hb with several lupus-associated autoantigens; co-incubation of ferric Hb with apoptotic blebs (structures which contain packaged autoantigens, believed to trigger lupus autoreactivity) revealed synergies (in terms of cytokine release and autoantibody production in vitro) that were also restricted to the lupus genotype. Infusion of ferric Hb into NZM2410 mice led to enhanced release of lupus-associated cytokines, the generation of a spectrum of autoantibodies, and enhanced-onset glomerulosclerosis. Given that the biased recognition of ferric Hb in a lupus milieu, in concert with lupus-associated autoantigens, elicits the generation of inflammatory cytokines from multiple immune cell types and stimulates the generation of potentially pathogenic autoantibodies, neutralization of Hb could have beneficial effects.

Axioms of mathe- matical immunology

2001 ◽  
Vol 38 (1-4) ◽  
pp. 13-43 ◽  
Author(s):  
T. Szabados ◽  
L. Varga ◽  
T. Bakács ◽  
Gábor Tusnády
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Free Energy ◽  
Immune System ◽  
B Cells ◽  
Positive Selection ◽  
Immune Cell ◽  
Host Cells ◽  
Energy Minimum ◽  
Free Energy Minimum

Current wisdom describes the immune system as a defense against microbial pathogens. It is claimed that the virgin immune system has a capacity to produce antibodies against the entire antigenic universe. We assume, by contrast, that the responding capacity of the immune system is limited. Thus it cannot stand in readiness to deal with a practi- cally endless diversity and abundance of microbes. Axioms and theorems are suggested for a mathematician audience delineating how the immune system could use its limited resources economically. It is suggested that the task of the immune system is twofold: (i) It sustains homeostasis to preserve the genome by constant surveillance of the intracellular antigenic milieu. This is achieved by standardization of the T cell repertoire through a positive selection. The driving force of positive selection is immune cell survival. T cells must constantly seek contact with complementary MHC structures to survive. Such contact is based on molecular complementarity between immune cell receptors and MHC/self-peptide complexes. At the highest level of complementarity a local free energy minimum is achieved, thus a homeostatic system is created. Homeostatic interactions happen at intermediate afinity and are reversible. Alteration in the presented peptides typically decreases complementarity. That pushes the system away from the free energy minimum, which activates T cells. Complementarity is restored when cytotoxic T cells destroy altered (mutated/infected) host cells. (ii) B cells carry out an immune response to foreign proteins what requires a change in the genome. B cells raised under the antigenic in uence of the normal intestinal micro o- ra, self-proteins and alimentary antigens must go through a hypermutation process to be able to produce specific antibodies. It has a certain probability that hypermutation will successfully change the genome in some clones to switch from low afinity IgM antibody production to high afinity IgG production. Interactions (typically antibody antigen reac- tions) in an immune response happen at high afinity and are irreversible. High afinity clones will be selected, stimulated and enriched by the invading microbes. A complete account of the course of an infectious disease must also include a descrip- tion of the ecology of the immune response. It is therefore suggested that during prolonged interaction between host and infectious organism, carried on across many generations, the adaptive antibody population may facilitate the evolution of the natural antibody reper- toire, in accordance with the Baldwin effect in the evolution of instinct (see Appendix 6).

Age-related changes in circannual rhythms of lymphocyte blastogenic responses in mice

1987 ◽  
Vol 252 (2) ◽  
pp. R299-R305
Author(s):  
M. A. Brock
Keyword(s):  
T Cells ◽  
Immune System ◽  
B Cells ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Tritiated Thymidine ◽  
Age Related ◽  
Dividing Cells ◽  
Age Related Changes

Blastogenic responses to T- and B-lymphocyte mitogens were tested in suspensions of splenocytes from 15- and 24- to 28-mo-old C57BL/6 mice and compared with analogous responses in young animals. The mice were housed under constant environmental conditions with alternating light-dark cycles (LD 12:12). Single cell suspensions were cultured in vitro with mitogens, and the induced incorporation of tritiated thymidine by dividing cells was determined. Increases in periodicity of responses to concanavalin A and phytohemagglutinin by T cells and to lipopolysaccharide by B cells and lower mean levels of activation characterized rhythms in cells from 15-mo-old and senescent mice compared with young animals. Amplitudes of the rhythms were unchanged at 15 mo, but by 24 mo of age rhythmic responses of T but not B cells were damped. The separable effects of age on expression of circannual rhythms by T and B lymphocytes suggest another mechanism for imbalance in the immune system. Phases of depressed responses that are extended for several months in populations of older mice could provide increased opportunities for environmental assaults.

scholarly journals Pregnancy-Associated Alterations of Peripheral Blood Immune Cell Numbers in Domestic Sows Are Modified by Social Rank

Animals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 112
Author(s):  
Christiane Schalk ◽  
Birgit Pfaffinger ◽  
Sonja Schmucker ◽  
Ulrike Weiler ◽  
Volker Stefanski
Keyword(s):  
T Cells ◽  
Immune System ◽  
B Cells ◽  
Plasma Cortisol ◽  
Immune Cell ◽  
Cytotoxic T Cells ◽  
Social Rank ◽  
Γδ T Cells ◽  
Detailed Knowledge ◽  
Immune Functions

During pregnancy, the maternal immune system is characterized by a shift from adaptive to innate immune functions. Besides, the immune system can be influenced by social rank. Detailed knowledge of pregnancy-associated immune changes and of the interplay of rank-associated and gestation-induced immunomodulations is still fragmentary in sows. This study investigates both the numbers of various blood leukocyte subpopulations during pregnancy and the influence of social rank position on progressing pregnancy-associated alterations in group-housed sows. Sows were classified as low (LR), middle (MR), or high-ranking (HR). Five blood samples were collected from each of the 35 sows throughout pregnancy to evaluate the distribution of blood lymphocyte subpopulations and plasma cortisol concentrations. The numbers of T, natural killer (NK), and B cells, cytotoxic T cells (CTL), and CD8+ γδ- T cells decreased during the last trimester of pregnancy, while neutrophils and plasma cortisol concentration increased before parturition. Social rank revealed different effects on B cells and monocytes with MR sows showing higher numbers than LR sows. Plasma cortisol concentrations also tended to be higher in MR sows as compared to LR sows. In conclusion, sows show pregnancy-associated alterations in the immune system, which are influenced by social rank, as middle-ranking sows in particular display signs of stress-induced immunomodulations.

scholarly journals Direct interactions between B and T lymphocytes bearing complementary receptors.

1986 ◽  
Vol 163 (1) ◽  
pp. 189-202 ◽  
Author(s):  
J P Tite ◽  
J Kaye ◽  
K M Saizawa ◽  
J Ming ◽  
M E Katz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cell Line ◽  
Direct Interaction ◽  
Antigenic Determinants ◽  
Th Cell ◽  
Low Concentrations

A murine cloned Th cell line specific for the antigen conalbumin in the context of self I-A molecules can be activated by low concentrations of soluble antireceptor mAb. By using an antireceptor mAb to shared antigenic determinants on T cell receptors, we have shown that the ability to be activated by soluble antireceptor mAb is an unusual, although not unique, feature of this cloned T cell line. This activation does not involve occult APC, FcR, or interaction between individual cloned T cells, as limiting-dilution analysis shows that individual cells of this clone will grow in the presence of the antireceptor antibody and IL-1 as stimulus. This cloned T cell line is highly immunogenic in vivo, giving rise to antireceptor antibodies that stimulate its growth in both mice and rats. This response is not dependent upon exogenous T cells. Rather, the clone directly interacts with complementary B cells, as shown by the production of mAb in nude mice, and by production of stimulating antireceptor antibodies by purified B cells cultured with cloned Th cells in vitro. Several features of this cloned Th cell line, most especially its ability to be activated, rather than inhibited, by antireceptor antibodies, may account for its striking ability to directly activate B cells bearing complementary receptors. The direct interaction of the cloned Th cell with B cells bearing complementary receptors may serve as a model for receptor-receptor interactions in the generation of both T and B cell repertoires.

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