Peripheral Blood-derived Lymphocytes Research Articles

Cystatin F Depletion in Mycobacterium tuberculosis-Infected Macrophages Improves Cathepsin C/Granzyme B-Driven Cytotoxic Effects on HIV-Infected Cells during Coinfection.

Cystatin F (CstF) is a protease inhibitor of cysteine cathepsins, including those involved in activating the perforin/granzyme cytotoxic pathways. It is targeted at the endolysosomal pathway but can also be secreted to the extracellular milieu or endocytosed by bystander cells. CstF was shown to be significantly increased in tuberculous pleurisy, and during HIV coinfection, pleural fluids display high viral loads. In human macrophages, our previous results revealed a strong upregulation of CstF in phagocytes activated by interferon γ or after infection with Mycobacterium tuberculosis (Mtb). CstF manipulation using RNA silencing led to increased proteolytic activity of lysosomal cathepsins, improving Mtb intracellular killing. In the present work, we investigate the impact of CstF depletion in macrophages during the coinfection of Mtb-infected phagocytes with lymphocytes infected with HIV. The results indicate that decreasing the CstF released by phagocytes increases the major pro-granzyme convertase cathepsin C of cytotoxic immune cells from peripheral blood-derived lymphocytes. Consequently, an observed augmentation of the granzyme B cytolytic activity leads to a significant reduction in viral replication in HIV-infected CD4+ T-lymphocytes. Ultimately, this knowledge can be crucial for developing new therapeutic approaches to control both pathogens based on manipulating CstF.

Aberrant Migratory Behavior of Immune Cells in Recurrent Autoimmune Uveitis in Horses.

The participating signals and structures that enable primary immune cells migrating within dense tissues are not completely revealed until now. Especially in autoimmune diseases, mostly unknown mechanisms facilitate autoreactive immune cells to migrate to endogenous tissues, infiltrating and harming organ-specific structures. In order to gain deeper insights into the migratory behavior of primary autoreactive immune cells, we examined peripheral blood-derived lymphocytes (PBLs) of horses with equine recurrent uveitis (ERU), a spontaneous animal model for autoimmune uveitis in humans. In this study, we used a three-dimensional collagen I hydrogel matrix and monitored live-cell migration of primary lymphocytes as a reaction to different chemoattractants such as fetal calf serum (FCS), cytokines interleukin-4 (IL-4), and interferon-γ (IFN-γ), and a specific uveitis autoantigen, cellular retinaldehyde binding protein (CRALBP). Through these experiments, we uncovered distinct differences between PBLs from ERU cases and PBLs from healthy animals, with significantly higher cell motility, cell speed, and straightness during migration of PBLs from ERU horses. Furthermore, we emphasized the significance of expression levels and cellular localization of septin 7, a membrane-interacting protein with decreased abundance in PBLs of autoimmune cases. To underline the importance of septin 7 expression changes and the possible contribution to migratory behavior in autoreactive immune cells, we used forchlorfenuron (FCF) as a reversible inhibitor of septin structures. FCF-treated cells showed more directed migration through dense tissue and revealed aberrant septin 7 and F-actin structures along with different protein distribution and translocalization of the latter, uncovered by immunochemistry. Hence, we propose that septin 7 and interacting molecules play a pivotal role in the organization and regulation of cell shaping and migration. With our findings, we contribute to gaining deeper insights into the migratory behavior and septin 7-dependent cytoskeletal reorganization of immune cells in organ-specific autoimmune diseases.

A Functionally Different Immune Phenotype in Cattle Is Associated With Higher Mastitis Incidence.

A novel vaccine against bovine viral diarrhea (BVD) induced pathogenic antibody production in 5–10% of BVD-vaccinated cows. Transfer of these antibodies via colostrum caused Bovine neonatal pancytopenia (BNP) in calves, with a lethality rate of 90%. The exact immunological mechanisms behind the onset of BNP are not fully understood to date. To gain further insight into these mechanisms, we analyzed the immune proteome from alloreactive antibody producers (BNP cows) and non-responders. After in vitro stimulation of peripheral blood derived lymphocytes (PBL), we detected distinctly deviant expression levels of several master regulators of immune responses in BNP cells, pointing to a changed immune phenotype with severe dysregulation of immune response in BNP cows. Interestingly, we also found this response pattern in 22% of non-BVD-vaccinated cows, indicating a genetic predisposition of this immune deviant (ID) phenotype in cattle. We additionally analyzed the functional correlation of the ID phenotype with 10 health parameters and 6 diseases in a retrospective study over 38 months. The significantly increased prevalence of mastitis among ID cows emphasizes the clinical relevance of this deviant immune response and its potential impact on the ability to fight infections.

Description of organ-specific phenotype, and functional characteristics of tissue resident lymphocytes from liver transplantation donor and research on immune tolerance mechanism of liver.

AimPrior to transplantation, Donation after Cardiac Death (DCD) liver transplantation livers are perfused with preservation solution. Therefore, this provides an abundant source of human liver lymphocytes, as well as mesenteric lymph node and spleen for the study of lymphocyte subset diversity in the peripheral blood, lymph node, spleen and liver.MethodsLymphocyte subsets were isolated and purified from peripheral blood, lymph node, spleen and liver perfusion, the phenotypic and functional analysis of the tissue resident lymphocyte were performed by flow cytometry.ResultsIn a direct comparison between blood, liver, lymph node and spleen cells from liver transplantation donors, the abundance of natural killer (NK) cells, CD3+CD56+NKT (NT) cells and CD8+ T cells in intrahapatic lymphocytes (IHL) did not match what was present in peripheral blood and other peripheral lymphoid organs. The activation state of peripheral blood-derived lymphocytes was significantly different from lymph node-, spleen- and liver-derived cells. Intriguingly, NK cells, CD4+ T cells, and CD8+ T cells from liver perfusion display more suppressive characteristics, that is, express and produce more anti-inflammatory cytokine interleukin (IL)-10, less inflammatory cytokine interferon (INF)-γ.ConclusionOur findings imply that different tissues entail resident lymphocyte subsets with a distinct phenotype and function considering the organ is well vascularized, particularly in liver. It is better to understand the mechanism of liver immune tolerance.

Proteome Dynamics in Biobanked Horse Peripheral Blood Derived Lymphocytes (PBL) with Induced Autoimmune Uveitis.

Equine recurrent uveitis is the only spontaneous model for recurrent autoimmune uveitis in humans, where T cells target retinal proteins. Differences between normal and autoaggressive lymphocytes were identified in this study by analyzing peripheral blood derived lymphocytes (PBL) proteomes from the same case with interphotoreceptor retinoid binding protein induced uveitis sampled before (Day 0), during (Day 15), and after uveitic attack (Day 23). Relative protein abundances of PBL were investigated in a quantitative, label-free differential proteome analysis in cells that were kept frozen for 14 years since the initial experiment. Quantitative data could be acquired for 2632 proteins at all three time points. Profound changes (≥2-fold change) in PBL protein abundance were observed when comparing Day 0 with 15, representing acute inflammation (1070 regulated proteins) and Day 0 with 23 (cessation; 1571 regulated). Significant differences applied to proteins with functions in integrin signaling during active uveitis, involving "Erk and pi-3 kinase are necessary for collagen binding in corneal epithelia," "integrins in angiogenesis," and "integrin-linked kinase signaling" pathways. In contrast, at cessation of uveitic attack, significantly changed proteins belonged to pathways of "nongenotropic androgen signaling," "classical complement pathway," and "Amb2 integrin signaling." Several members of respective pathways were earlier shown to be changed in naturally occurring uveitis, underscoring the significance of these findings here and proofing the value of the induced model in mimicking spontaneous autoimmune uveitis. All MS data have been deposited to the ProteomeXchange consortium via the PRIDE partner repository (dataset identifier PXD005580).

Use of peripheral blood for production of buffalo (Bubalus bubalis) embryos by handmade cloning

Buffalo embryos were produced by handmade cloning using peripheral blood-derived lymphocytes as donor cells. Although the blastocyst rate was lower (P < 0.01) for lymphocyte- than control skin fibroblast-derived embryos (6.6 ± 0.84% vs. 31.15 ± 2.97%), the total cell number (152.6 ± 23.06 vs. 160.1 ± 13.25) and apoptotic index (6.54 ± 0.95 vs. 8.45 ± 1.32) were similar. The global level of H3K9ac was higher (P < 0.05) in lymphocyte- than that in skin-derived blastocysts; whereas in IVF blastocysts, the level was not significantly different from the two cloned groups. The level of H3K27me3 was similar among the three groups. The expression level of DNMT1, DNMT3a, HDAC1, and IGF-1R was higher (P < 0.01) in lymphocytes than that in skin fibroblasts. The expression level of CDX2 was higher (P < 0.05) than that of DNMT3a, IGF-1R, OCT4, and NANOG was lower (P < 0.05) in lymphocyte-derived than in IVF blastocysts; that of DNMT1 and HDAC1 was similar in the two groups. The expression level of all these genes, except that of NANOG, was lower (P < 0.05) in lymphocyte- than in skin fibroblast-derived blastocysts. It is concluded that, peripheral blood-derived lymphocytes can be used for producing handmade cloning embryos in bubaline buffaloes.

Escalating regulation of 5T4-specific IFN-γ+ CD4+ T cells distinguishes colorectal cancer patients from healthy controls and provides a target for in vivo therapy.

The relationship between the adaptive CD4+ T cell response and human cancer is unclear. The oncofetal antigen 5T4 is expressed on many human carcinomas, including colorectal cancer (CRC) cells, but has limited expression on normal tissues. We previously identified anti-5T4 CD4+ T cells in a proportion of CRC patients, and we extended this study to examine whether the quality or quantity of the T cell response reflects tumor stage. An overlapping peptide library spanning 5T4 was used as a target to enumerate cognate IFN-γ+CD4+ T-cells (measured as spot forming cells [SFC]/105 cultured T cells) in peripheral blood-derived lymphocytes following a 12-day in vitro culture period comparing patients pre-operatively (n = 27) to healthy controls (n = 17). Robust 5T4-specific T cell responses were present in 100% of healthy donors. There was a steady loss of T cell responses with advancing tumors with a significant negative correlation from stage I to III (P = 0.008). The predictability of the decline meant < 200 SFC/105 was only found in subjects with stage III CRC. The mechanism of loss of T cell response is independent of HLA-DR type or patient age, but does correspond to increases in Foxp3+ regulatory T cells (Tregs). Using low-dose cyclophosphamide to reduce the proportion of Tregs in vivo resulted in increased anti-5T4 T cell responses in CRC patients. The selective loss of 5T4-specific IFN-γ+CD4+ T cell responses implies a link between tumor stage and antitumor Th1 effector function; depleting Tregs can enhance such responses.

Effect of CD4+CD25+ and CD4+CD25− T Regulatory Cells on the Generation of Cytolytic T Cell Response to a Self but Human Tumor-Associated Epitope In Vitro

CD4+ T cells naturally expressing CD25 molecules (natural T regulatory cells (Tregs)) have a role in maintaining self tolerance and in regulating responses to infectious agents, transplantation Ags, and tumor Ags. CD4+ Tregs induced from CD4+CD25- precursors (induced Tregs) also regulate immune responses in the periphery. However, which of these Tregs is a major impediment in generating antitumor CTL responses is not clear. We show that although the CD4+CD25+ subsets isolated from peripheral blood-derived lymphocytes do suppress the proliferation of CD4+CD25- effector T cells, they do not suppress the activation and expansion of the self but melanoma-associated, melanoma Ag-reactive T cell 1 (MART-1)27-35-specific CD8+ T cells stimulated by the respective peptide-loaded matured dendritic cells in vitro. The CD4+CD25- counterparts, in contrast, lead to the generation of CD25+ glucocorticoid-inducible TNFR+-Forkhead/winged helix transcription factor+ populations and efficiently suppress the activation and expansion of the MART-127-35 epitope-specific CTLs. Our data suggest that when CTL precursors are optimally stimulated, natural Tregs are not a formidable constraint toward generating a robust antitumor CTL response, but induced Tregs could be.

Human Mig chemokine: biochemical and functional characterization.

Mig is a chemokine of the CXC subfamily that was discovered by differential screening of a cDNA library prepared from lymphokine-activated macrophages. The mig gene is inducible in macrophages and in other cells in response to interferon (IFN)-gamma. We have transfected Chinese hamster ovary (CHO) cells with cDNA encoding human Mig and we have derived CHO cell lines from which we have purified recombinant human Mig (rHuMig). rHuMig induced the transient elevation of [Ca2+]i in human tumor-infiltrating T lymphocytes (TIL) and in cultured, activated human peripheral blood-derived lymphocytes. No responses were seen in human neutrophils, monocytes, or Epstein-Barr virus-transformed B lymphoblastoid cell lines. rHuMig was chemotactic for TIL by a modified Boyden chamber assay but rHuMig was not chemotactic for neutrophils or monocytes. The CHO cell lines, IFN-gamma-treated human peripheral-blood monocytes, and IFN-gamma-treated cells of the human monocytic cell line THP-1 all secreted multiple and identical HuMig species as revealed by SDS-PAGE. Using the CHO-derived rHuMig, we have shown that the species' heterogeneity is due to proteolytic cleavage at basic carboxy-terminal residues, and that the proteolysis occurs before and not after rHuMig secretion by the CHO cells. The major species of secreted rHuMig ranged from 78 to 103 amino acids in length, the latter corresponding to the full-length secreted protein predicted from the HuMig cDNA. Carboxy-terminal-truncated forms of rHuMig were of lower specific activity compared to full-length rHuMig in the calcium flux assay, and the truncated species did not block the activity of the full-length species. It is likely that HuMig plays a role in T cell trafficking and perhaps in other aspects of the physiology of activated T cells.

Immunological functions of mouse liver resident high density lymphocytes

Liver-derived high density lymphocytes (Matsunaga cells) have been detected as members of resident T cells in the mouse liver. In this study, we assessed the immunological functions of liver-derived high density lymphocytes of BALB/c mice in comparison with those derived from spleen and peripheral blood. Liver-derived high density lymphocytes proliferated in response to the syngeneic and allogeneic mixed lymphocyte reaction, as well as those derived from spleen and peripheral blood. The allo-activated cytotoxic T lymphocyte activity of liver-derived high density lymphocytes against PHA-blasts of C57BL/6 mice was lower than that of spleen- and peripheral blood-derived lymphocytes. The suppressor activity of syngeneic- or allo-activated high density lymphocytes of the liver, spleen, and the peripheral blood was assessed by measuring their suppressive effect on the proliferation or on the generation of allo-specific cytotoxic activity in allogeneic mixed lymphocyte reaction. The suppression was concentration-dependent and strongest in liver-derived lymphocytes.

IgE and IgG subclass regulation by IL-4 and IFN-gamma in human helminth infections. Assessment by B cell precursor frequencies.

Helminth infections, like atopic disorders, show characteristic elevations of serum IgE and IgG4. To examine the mechanisms underlying the regulation of these two isotypes and of the other IgG subclasses, the frequency (Fo) of isotype-specific B lymphocytes (Bc) from 11 patients with helminth infections was compared by filter-spot ELISA using fresh peripheral blood-derived lymphocytes after 14-day Ag stimulation in vitro. The role of IL-4 and IFN-gamma in the generation and regulation of Ag-driven isotype responses was determined. The Fo of freshly obtained lymphocytes (expressed/10(5) Bc) secreting polyclonal Ig for the following isotypes was: IgE (geometric mean = 0.72; range, 0 to 17.7); IgG4 (geometric mean = 4.9; range, 1.8 to 24.4); IgG1 (geometric mean = 134.3; range, 16.7 to 318). The Fo of IgE correlated with IgG4-secreting Bc among study subjects (r = 0.8, p < 0.01), however there was no association with the other isotypes. Parasite Ag added to cultured lymphocytes induced significant expansion in the number of Ig-secreting Bc for IgE and all IgG subclasses. In contrast, addition of a nonparasite Ag, tetanus toxoid, generated increased Fo of Ig-secreting Bc for IgG1, IgG2, and IgG3, and no expansion of IgG4 or IgE. The essential role of IL-4 in the expansion of IgE- and IgG4-secreting B cells in response to filarial Ag was demonstrated when simultaneous addition of neutralizing anti-IL-4 antibodies completely inhibited this response in all 11 patients studied. Neutralizing anti-IL-4 had no effect on either filarial or tetanus toxoid-driven expansion of IgG1-, IgG2-, or IgG3-secreting Bc. An inhibitory role of endogenously produced IFN-gamma was also shown when addition of neutralizing anti-IFN-gamma to cultures significantly augmented Ag-driven expansion of Bc-secreting IgE and all IgG subclasses; IgE, 0.4- to 9-fold; IgG4, 1.4- to 12-fold; IgG1, 1.6- to 13-fold; IgG2, 1.9- to 5-fold; and IgG3, 2.7- to 6-fold. This study demonstrates that parasite Ag stimulates Bc expansion in helminth-infected patients. Although this response for all five isotypes studied is down-regulated by IFN-gamma, the generation of only the IgE and IgG4 responses appears to be mediated selectively by IL-4. These findings support the concept that IgE and IgG4 production are linked and related to the quantities of IL-4 and IFN-gamma induced by Ag-specific T cells.

Signaling requirements for the expression of the transactivating factor NF‐AT in human T lymphocytes

A protein called nuclear factor of activated T cells (NF-AT) binds to DNA sequences within the enhancer region of the interleukin 2 (IL 2) gene and appears necessary for both the inducibility and T cell specificity of IL 2 expression. IL 2 production is regulated by multiple signals including those generated via activation of the T cell antigen receptor complex (TcR/CD3), CD2 antigen, protein kinase C (PKC) or elevation of intracellular free calcium concentration ([Ca2+]i). We have, therefore, explored the role of these different stimuli in regulating the nuclear expression of NF-AT in human peripheral blood-derived lymphocytes. Results presented herein indicate that maximal expression of NF-AT in T cells requires at least two signals: PKC activation and TcR/CD3 or CD2 triggering, [Ca2+]i increases and TcR/CD3 or CD2 triggering. Data are presented that indicate that either the [Ca2+]i or PKC signal generated via the TcR/CD3 complex would not alone induce NF-AT expression, and that the TcR/CD3 complex probably regulates NF-AT expression because of its ability to regulate multiple intracellular signals in T cells, and not via any single biochemical event. The combination of CD2 mAb GT2/OKT11 used in the present study to trigger the CD2 antigen is able to act in synergy with phorbol 12,13-dibutyrate or ionomycin to induce NF-AT expression. However, these CD2 mAb do not elevate [Ca2+]i or activate PKC, suggesting that signals other than [Ca2+]i or PKC can regulate NF-AT expression in peripheral blood-derived T cells.

Phenotypic and functional characteristics of activated CD8 + cells: A CD11b −CD28 − subset mediates noncytolytic functional suppression

Freshly isolated human CD8 + cells can be divided into mutually exclusive subsets bearing the phenotypes CD11b +(CD28 −) or CD28 +(CD11b −). We found that activation of CD8 + cells with anti-CD3 mAb and IL-2 preferentially expanded the CD11b −(CD28 +) subset. This subset, when separated and activated independently, mediated both functional suppression and lectin-dependent cell cytotoxicity (LDCC). CD28 − cells, prepared by elimination of the CD28 + cells from expanded unfractionated CD8 + cell cultures, retained functional suppressor activity but demonstrated reduced LDCC compared to either the CD28 +(CD11b −)-enriched fraction or the unfractionated CD8 + population. The majority of the CD28 − cells were also CD11b −, reflecting the observation that initially CD11b + cells lose CD11b expression following activation with anti-CD3 mAb and IL-2. Our results therefore indicate that CD8 + cells deriving from the CD11b +CD28 − subset, but expressing neither CD11b nor CD28 after activation, represent the main noncytotoxic functional suppressor cell in the mitogen “activated” suppressor assay. The preferential expansion of CD8 +CD28 + cells relative to CD8 +CD28 − cells, if occuring in vivo in the central nervous system (CNS) compartment, would be consistent with observed phenotypic analysis of cerebrospinal fluid-derived T cells and might contribute to the reduced functional suppressor activity previously found for CNS compared to peripheral blood-derived lymphocytes.

The Effect of Cyclosporine A on Infection of Susceptible Cells by Human Immunodeficiency Virus Type 1

The effect of cyclosporine A (CyA) on the ability of the human immunodeficiency virus type 1 (HIV-1) to infect the H-9 T-cell leukemic line, as well as interleukin-2 (IL-2)-grown human peripheral blood-derived lymphocytes, has been studied. Pretreatment of H-9 cells and human lymphocytes with CyA over 24 hours completely prevented viral infection over a 21-day period, whereas the addition of drug at two hours postinfection with HIV-1 had a significant inhibitory effect on viral replication and expression of the virus-specific antigens p17 and p24. However, if CyA was added at later times to these lymphocytic cells, this inhibitory effect was lost. Indeed, the removal of CyA from cultures that had been treated from two hours after infection led to the rapid production of progeny virus. HIV-1 was able to infect peripheral blood lymphocytes obtained from each of four kidney allograft recipients on long-term CyA antirejection therapy, as long as drug was not included in the culture medium. In addition, we asked what effect pretreatment with CyA of cells of the U-937 monocytic line and primary cultures of human monocytes/macrophages might have on infection by HIV-1. CyA had no demonstrable effect on the ability of HIV-1 to infect cells of either type.