scholarly journals African Green Monkey TRIM5α Restriction in Simian Immunodeficiency Virus-Specific Rhesus Macaque Effector CD4 T Cells Enhances Their Survival and Antiviral Function

2015 ◽  
Vol 89 (8) ◽  
pp. 4449-4456 ◽  
Author(s):  
Sumiti Jain ◽  
Matthew T. Trivett ◽  
Victor I. Ayala ◽  
Claes Ohlen ◽  
David E. Ott
Keyword(s):  
T Cells ◽  
T Cell ◽  
Rhesus Macaque ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
T Cell Clones ◽  
Cell Clones ◽  
Immunodeficiency Virus ◽  
Antiviral Function

ABSTRACTThe expression of xenogeneic TRIM5α proteins can restrict infection in various retrovirus/host cell pairings. Previously, we have shown that African green monkey TRIM5α (AgmTRIM5α) potently restricts both human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus mac239 (SIVmac239) replication in a transformed human T-cell line (L. V. Coren, et al., Retrovirology 12:11, 2015,http://dx.doi.org/10.1186/s12977-015-0137-9). To assess AgmTRIM5α restriction in primary cells, we transduced AgmTRIM5α into primary rhesus macaque CD4 T cells and infected them with SIVmac239. Experiments with T-cell clones revealed that AgmTRIM5α could reproducibly restrict SIVmac239replication, and that this restriction synergizes with an intrinsic resistance to infection present in some CD4 T-cell clones. AgmTRIM5α transduction of virus-specific CD4 T-cell clones increased and prolonged their ability to suppress SIV spread in CD4 target cells. This increased antiviral function was strongly linked to decreased viral replication in the AgmTRIM5α-expressing effectors, consistent with restriction preventing the virus-induced cytopathogenicity that disables effector function. Taken together, our data show that AgmTRIM5α restriction, although not absolute, reduces SIV replication in primary rhesus CD4 T cells which, in turn, increases their antiviral function. These results support priorin vivodata indicating that the contribution of virus-specific CD4 T-cell effectors to viral control is limited due to infection.IMPORTANCEThe potential of effector CD4 T cells to immunologically modulate SIV/HIV infection likely is limited by their susceptibility to infection and subsequent inactivation or elimination. Here, we show that AgmTRIM5α expression inhibits SIV spread in primary effector CD4 T cellsin vitro. Importantly, protection of effector CD4 T cells by AgmTRIM5α markedly enhanced their antiviral function by delaying SIV infection, thereby extending their viability despite the presence of virus. Ourin vitrodata support priorin vivoHIV-1 studies suggesting that the antiviral CD4 effector response is impaired due to infection and subsequent cytopathogenicity. The ability of AgmTRIM5α expression to restrict SIV infection in primary rhesus effector CD4 T cells now opens an opportunity to use the SIV/rhesus macaque model to further elucidate the potential and scope of anti-AIDS virus effector CD4 T-cell function.

scholarly journals Expression of nerve growth factor and nerve growth factor receptor tyrosine kinase Trk in activated CD4-positive T-cell clones

1993 ◽  
Vol 90 (23) ◽  
pp. 10984-10988 ◽  
Author(s):  
P B Ehrhard ◽  
P Erb ◽  
U Graumann ◽  
U Otten
Keyword(s):  
T Cells ◽  
Nerve Growth Factor ◽  
T Cell ◽  
Growth Factor ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
T Cell Clones ◽  
Nerve Growth ◽  
Cell Clones ◽  
Ngf Receptor

Recent evidence suggests that nerve growth factor (NGF), in addition to its neurotrophic functions, acts as an immunomodulator mediating "cross-talk" between neuronal and immune cells, including T lymphocytes. We have analyzed murine CD4+ T-cell clones for their ability to express transcripts encoding NGF, low-affinity NGF receptor, and trk protooncogene, the signal-transducing receptor subunit for NGF. We show that two CD4+ T-helper (Th) clones, Th0-type clone 8/37 and Th2-type clone D10.G4.1, express NGF and Trk mRNA after appropriate activation with mitogen or with antigen and antigen-presenting cells. NGF and trk induction occurred to a similar extent and over a similar time course in activated 8/37 T cells, raising the possibility that NGF and trk genes are under coordinate control. NGF and NGF receptor expression does not seem to be a universal property of all activated CD4+ T cells, since Th1-type clone 9/9 did not express any of the transcripts after either stimulation. The absence of low-affinity NGF receptor mRNA in resting and activated T cells implies that the low-affinity NGF receptor is not involved in NGF signal transduction in CD4+ T cells. Our finding that activated CD4+ T-cell clones not only express Trk but also synthesize and release biologically active NGF implicates NGF as an autocrine and/or paracrine factor in the development and regulation of immune responses.

A Novel Strategy for Generation of Human Tumor-Specific T Cell Clones for Adoptive Transfer.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3713-3713
Author(s):  
Seung-Tae Lee ◽  
Shujuan Liu ◽  
Pariya Sukhumalchandra ◽  
Jeffrey Molldrem ◽  
Patrick Hwu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Autologous Tumor ◽  
T Cell Clones ◽  
Cell Clones ◽  
T Cell Lines

Abstract Adoptive T-cell therapy using donor lymphocyte infusions is a promising approach for treating hematological malignancies. But, efficacy is limited by the induction of graft-versus-host disease. Transfer of tumor-specific T-cell clones could enhance the graft-versus-tumor effect and eliminate graft-versus-host disease. However, isolating antigen-specific T-cell clones by the traditional limiting dilution approach is a time-consuming and laborious process. Here, we describe a novel strategy for rapidly cloning tumor-specific T cells. Lymphoma-specific T-cell lines were generated from two follicular lymphoma patients by repeated in vitro stimulation of lymphocytes isolated from tumor or blood with autologous soluble CD40 ligand-activated tumor cells. After four in vitro stimulations at 10-day intervals in the presence of IL-2 and IL-15, T-cell lines were found to be predominantly CD4+ T cells and produced significant amounts of TNF-a, GM-CSF, and IFN-γ in response to autologous tumor cells. The tumor reactivity was MHC class II restricted suggesting that it was mediated by CD4+ T cells. Staining with a TCR Vb antibody panel, a set of monoclonal antibodies against 24 human TCR Vb families, revealed that certain Vb families were overrepresented in each CD4+ T-cell line. In patient 1, 51% of CD4+ T cells were Vb1 positive, and in patient 2, 27% of CD4+ T cells were Vb8 positive. To clone lymphoma-specific T cells, CD4+ T-cell lines were labeled with CFSE and stimulated with autologous tumor cells. After 9 days of in vitro expansion in the presence of IL-2 and IL-15, CD4+ T-cell lines were stained with an anti-human CD4-APC monoclonal antibody and an anti-human TCR Vb-PE monoclonal antibody for each CD4+ T-cell line. Proliferating Vb1 cells from patient 1 and Vb8 cells from patient 2 were identified by their reduction in CFSE staining, and CD4+TCRV b +CFSEdim cells were sorted by flow cytometer. Monoclonality of the sorted cells was confirmed by PCR using a panel of optimized primers specific for 24 TCR Vb families, by TCR Vb spectratype analysis, and finally, by sequencing the TCR Vb gene used by each T-cell clone. Sorted tumor-specific T-cell clones could be expanded to large numbers using a 14-day rapid expansion protocol with allofeeder PBMCs, and confirmed to retain specificity against autologous tumor cells in a cytokine induction assay. This approach was also successfully used to isolate melanoma-specific CD8+ T-cell clones from two patients. We conclude that this approach is highly reproducible, rapid, and efficient for generating antigen-specific T-cell clones for adoptive T-cell therapy against human malignancies in the autologous or allogeneic setting.

Human Alloreactive CD4+ T Cells as Potent Effector Cells and Sole Mediators of Anti-Tumor Responses in a NOD/SCID Mouse Model for Human Acute Leukemia.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1245-1245 ◽  
Author(s):  
Sanja Stevanovic ◽  
Marieke Griffioen ◽  
Marianke LJ Van Schie ◽  
Roelof Willemze ◽  
J.H. Frederik Falkenburg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Class Ii ◽  
Hla Class Ii ◽  
Cd4 T Cell ◽  
Leukemic Cells ◽  
T Cell Clones ◽  
Hla Dr ◽  
Cell Clones

Abstract Donor lymphocyte infusion (DLI) following allogeneic stem cell transplantation (alloSCT) can be a curative treatment for patients with hematological malignancies. The therapeutic benefit of DLI is attributed to a graft versus leukemia (GvL) reactivity mediated by donor T cells recognizing allo-antigens on malignant cells of the patient. Donor T cells, however, often recognize allo-antigens which are broadly expressed in non-malignant tissues of the patient, thereby causing severe graft versus host disease (GvHD). In contrast to HLA class I molecules which are ubiquitously expressed on all nucleated cells, HLA class II molecules are predominantly expressed on cells of the hematopoietic system, and therefore CD4+ T cells may selectively mediate GvL reactivity without GvHD. Several clinical studies have indeed demonstrated that CD8-depleted DLI after alloSCT can lead to clinical remissions with reduced incidence of GvHD. Since in most of these studies DLI was contaminated with CD8+ T cells, it remained unclear whether CD4+ T cells alone are capable of mediating GvL reactivity. To assess the capacity of purified CD4+ T cells to solely exert GvL reactivity we compared the anti-tumor effects of CD4+ DLI and CD3+ DLI in a NOD/SCID mouse model of human acute leukemia. Iv injection of primary human leukemic cells from three different patients reproducibly resulted in engraftment of leukemia in mice, as monitored by peripheral blood analysis. Three weeks after inoculation of leukemic cells, established tumors were treated by infusion of human donor T cells. In mice treated with CD4+ DLI (5*106 CD4+ T cells), the emergence of activated (HLA-DR+) T cells coincided with rapid disappearance of leukemic cells, showing similar kinetics as for CD3+ DLI (consisting of 5*106 CD4+ T cells and 3*106 CD8+ T cells). To analyze the specific reactivity of T cells responsible for the anti-leukemic effect, we clonally isolated human CD45+ T cells during the anti-tumor response following CD4+ DLI in which the donor was matched for HLA class I and mismatched for the HLA-DR (DRB1*1301), -DQ (DQB1*0603) and –DP (DPB1*0301/0401) alleles of the patient. A total number of 134 CD4+ T cell clones were isolated expressing various different TCR Vbeta chains. Most of the isolated CD4+ T cell clones (84%) were shown to be alloreactive, as determined by differential recognition of patient and donor EBV-transformed B cells (EBV-LCL) in IFN-g ELISA. A substantial number of these CD4+ T cell clones also exerted cytolytic activity (17%), as demonstrated by specific reactivity with patient EBV-LCL but not donor EBV-LCL in a 10 hr 51Cr-release cytotoxicity assay. Further characterization of the specificity of 20 CD4+ T cell clones using blocking studies with HLA class II specific monoclonal antibodies illustrated HLA class II restricted recognition directed against HLA-DR (n=3), HLA-DQ (n=16) and HLA-DP (n=1) molecules of the patient. Of the 127 alloreactive CD4+ T cell clones, only 36 clones directly recognized primary leukemic cells of the patient. Flowcytometric analysis demonstrated that HLA class II, and in particular HLA-DQ, molecules were expressed at relatively low levels on patient leukemic cells as compared to patient EBV-LCL. Upregulation of HLA class II and costimulatory molecules on patient leukemic cells upon differentiation in vitro into leukemic antigen presenting cells (APC) resulted in recognition of patient leukemic cells by all alloreactive CD4+ T cell clones. Therefore, we hypothesize that the alloreactive CD4+ T cells have been induced in vivo by patient leukemic cells, which, upon interaction with T cells or other environmental factors, acquired an APC phenotype. In conclusion, our data show that alloreactive CD4+ T cells can be potent effector cells and sole mediators of strong antitumor responses in a NOD/SCID mouse model for human acute leukemia.

Identification of Four New HLA Class II Restricted Minor Histocompatibility Antigens Contributing to Graft Versus Leukemia Reactivity.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3247-3247
Author(s):  
Anita N. Stumpf ◽  
Edith D. van der Meijden ◽  
Cornelis A.M. van Bergen ◽  
Roelof Willemze ◽  
J.H. Frederik Falkenburg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
Cd4 T Cell ◽  
Class I ◽  
T Cell Clones ◽  
Cell Clones

Abstract Patients with relapsed hematological malignancies after HLA-matched hematopoietic stem cell transplantation (HSCT) can be effectively treated with donor lymphocyte infusion (DLI). Donor-derived T cells mediate beneficial graft-versus-leukemia (GvL) effect but may also induce detrimental graft-versus-host disease (GvHD). These T cell responses are directed against polymorphic peptides which differ between patient and donor due to single nucleotide polymorphisms (SNPs). These so called minor histocompatibility antigens (mHag) are presented by HLA class I or II, thereby activating CD8+ and CD4+ T cells, respectively. Although a broad range of different HLA class I restricted mHags have been identified, we only recently characterized the first autosomal HLA class II restricted mHag phosphatidylinositol 4-kinase type 2 beta (LB-PI4K2B-1S; PNAS, 2008, 105 (10), p.3837). As HLA class II is predominantly expressed on hematopoietic cells, CD4+ T cells may selectively confer GvL effect without GvHD. Here, we present the molecular identification of four new autosomal HLA class II restricted mHags recognized by CD4+ T cells induced in a patient with relapsed chronic myeloid leukemia (CML) after HLAmatched HSCT who experienced long-term complete remission after DLI with only mild GvHD of the skin. By sorting activated CD4+ T cells from bone marrow mononuclear cells obtained 5 weeks after DLI, 17 highly reactive mHag specific CD4+ T cell clones were isolated. Nine of these T cell clones recognized the previously described HLADQ restricted mHag LB-PI4K2B-1S. The eight remaining T cell clones were shown to exhibit five different new specificities. To determine the recognized T cell epitopes, we used our recently described recombinant bacteria cDNA library. This method proved to be extremely efficient, since four out of five different specificities could be identified as new HLA-class II restricted autosomal mHags. The newly identified mHags were restricted by different HLA-DR molecules of the patient. Two mHags were restricted by HLA-DRB1 and were found to be encoded by the methylene-tetrahydrofolate dehydrogenase 1 (LBMTHFD1- 1Q; DRB1*0301) and lymphocyte antigen 75 (LB-LY75-1K; DRB1*1301) genes. An HLA-DRB3*0101 restricted mHag was identified as LB-PTK2B-1T, which is encoded by the protein tyrosine kinase 2 beta gene. The fourth mHag LB-MR1-1R was restricted by HLA-DRB3*0202 and encoded by the major histocompatibility complex, class I related gene. All newly identified HLA class II restricted mHags exhibit high population frequencies of 25% (LB-MR1-1R), 33% (LB-LY75-1K), 68% (LB-MTHFD1- 1Q), and 70% (LB-PTK2B-1T) and the genes encoding these mHags show selective (LY- 75) or predominant (MR1, MTHFD1, PTK2B) expression in cells of hematopoietic origin as determined by public microarray databases. All T cell clones directed against the newly identified mHags recognized high HLA class II-expressing B-cells, mature dendritic cells (DC) and in vitro cultured leukemic cells with antigen-presenting phenotype. The clone recognizing LB-MTHFD1-1Q also showed direct recognition of CD34+ CML precursor cells from the patient. In conclusion, we molecularly characterized the specificity of the CD4+ T cell response in a patient with CML after HLA-matched HSCT who went into long-term complete remission after DLI. By screening a recombinant bacteria cDNA library, four new different CD4+ T cell specificities were characterized. Our screening method and results open the possibility to identify the role of CD4+ T cells in human GvL and GvHD, and to explore the use of hematopoiesis- and HLA class II-restricted mHag specific T cells in the treatment of hematological malignancies.

Identification and Characterization of Human Aspergillus Fumigatus-Specific Tr1-(Like) Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 181-181
Author(s):  
Tanja Bedke ◽  
Sarah Lurati ◽  
Claudia Stuehler ◽  
Nina Khanna ◽  
Hermann Einsele ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Aspergillus Fumigatus ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Ifn Gamma ◽  
T Cell Clones ◽  
Suppressor T Cell ◽  
Cell Clones

Abstract Abstract 181 Introduction: The ubiquitous mold Aspergillus fumigatus (A. fumigatus) induces two forms of pathogenesis: invasive aspergillosis in neutropenic patients and allergic aspergillosis in patients with chronic obstructive lung disease as well as in immunosuppressed patients. Mouse models of aspergillosis suggest that not only effector T cells (Teff) but also regulatory T cells (Treg) play a crucial role for the regulation of a protective T cell-mediated immunity to A. fumigatus. However, it is little-known about the involvement of Treg during A. fumigatus infection in humans. In order to develop new therapeutical strategies for the treatment of aspergillosis this project aims to understand the influence of regulatory T cells on A. fumigatus infection in humans. Material/Methods: A. fumigatus-specific CD4+ T cell clones were established from PBMC of healthy donors. Based on this clone pool Treg clones were identified due to their inability to proliferate in the absence of costimulation assessed by 3[H]-TdR incorporation as well as their Ag-specific cytokine production and phenotype determined by flow cytometry. Treg function was analyzed by their ability to suppress proliferation of autologous CD4+ T cells using CFSE dilution. Results: We identified A. fumigatus-specific T cell clones that exhibited marginal detectable proliferation after restimulation with immobilized anti-CD3 mAb in the absence of costimulation. However, these T cell clones vigorously proliferated in response to restimulation with their cognate antigen. A more detailed characterization showed that these suppressor T cell clones produced high amounts of IL-10 and moderate levels of IFN-gamma upon Ag-specific restimulation and expressed low amounts of Foxp3 but not Helios, a transcription factor that had recently been linked to natural occurring Treg. Most importantly, these T cell clones suppressed Ag-specific expansion of CD4+ Teff. This effect was contact-independent since suppression of Ag-specific CD4+ T cell expansion detected in transwell experiments was comparable to cocultures that enabled cellular-contact. Furthermore, anti-CD3/CD28-induced proliferation of naïve CD4+ T cells was not reduced in the presence of culture supernatants obtained from suppressor T cell clones after their antigen-specific restimulation in the absence of DCs. Conclusions: We identified for the first time A. fumigatus-specific CD4+ T cell clones with a Tr1(-like) IL-10+IFN-gamma+Foxp3lowHelios− phenotype. These cells suppressed expansion of A. fumigatus-specific Teff in an Ag-specific manner mediated by soluble factors released from Tr1(-like) cell clones. Since these factors did not affect CD4+ T cell proliferation in the absence of DCs our data suggest, that Tr1(-like) cell clones rather negatively regulate the stimulatory capacity of DCs leading to a reduced expansion of Ag-specific CD4+ T cells. Therefore these Tr1(-like) cells might play a protective role during A. fumigatus infection in humans. Thus, adoptive transfer of A. fumigatus-specific Treg could be useful to enhance protective immunity in patients with chronic A. fumigatus infection. Disclosures: Topp: Micromet: Consultancy, Honoraria.

CD4+ T-cell clones recognizing human lymphoma-associated antigens: generation by in vitro stimulation with autologous Epstein-Barr virus–transformed B cells

Blood ◽  
2009 ◽  
Vol 114 (4) ◽  
pp. 807-815 ◽  
Author(s):  
Heather M. Long ◽  
Jianmin Zuo ◽  
Alison M. Leese ◽  
Nancy H. Gudgeon ◽  
Hui Jia ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Epstein Barr Virus ◽  
Hla Class Ii ◽  
Cd4 T Cell ◽  
T Cell Clones ◽  
Barr Virus ◽  
Cell Clones ◽  
Epstein Barr

Abstract Epstein-Barr virus (EBV)–specific T-cell preparations, generated by stimulating immune donor lymphocytes with the autologous virus-transformed B-lymphoblastoid cell line (LCL) in vitro, can be used to target EBV-positive malignancies. Although these preparations are enriched for EBV antigen–specific CD8+ T cells, most also contain a CD4+ T-cell population whose specificity is unknown. Here, we show that, although CD4+ T-cell clones derived from such cultures recognize HLA class II–matched LCLs but not mitogen-activated B lymphoblasts, many (1) do not map to any known EBV antigen, (2) can be raised from EBV-naive as well as EBV-immune persons, and (3) can recognize a broad range of human B lymphoma–derived cell lines irrespective of EBV genome status, providing those lines to express the relevant HLA class II–restricting allele. Importantly, such CD4+ clones not only produce IFNγ but are also cytotoxic and can control the outgrowth of HLA-matched lymphoma cells in cocultivation assays. We infer that such CD4+ T cells recognize cellular antigens that are preferentially up-regulated in EBV-transformed but not mitogen-activated B lymphoblasts and that are also expressed in a range of B-cell malignancies. Such antigens are therefore of potential value as targets for CD4+ T cell–based immunotherapy.

scholarly journals Antigen-responsive CD4+ T cell clones contribute to the HIV-1 latent reservoir

2020 ◽  
Vol 217 (7) ◽  
Author(s):  
Pilar Mendoza ◽  
Julia R. Jackson ◽  
Thiago Y. Oliveira ◽  
Christian Gaebler ◽  
Victor Ramos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Latent Reservoir ◽  
T Cell Clones ◽  
Cell Clones ◽  
Latently Infected ◽  
Hiv 1

Antiretroviral therapy suppresses but does not cure HIV-1 infection due to the existence of a long-lived reservoir of latently infected cells. The reservoir has an estimated half-life of 44 mo and is largely composed of clones of infected CD4+ T cells. The long half-life appears to result in part from expansion and contraction of infected CD4+ T cell clones. However, the mechanisms that govern this process are poorly understood. To determine whether the clones might result from and be maintained by exposure to antigen, we measured responses of reservoir cells to a small subset of antigens from viruses that produce chronic or recurrent infections. Despite the limited panel of test antigens, clones of antigen-responsive CD4+ T cells containing defective or intact latent proviruses were found in seven of eight individuals studied. Thus, chronic or repeated exposure to antigen may contribute to the longevity of the HIV-1 reservoir by stimulating the clonal expansion of latently infected CD4+ T cells.

scholarly journals The 26-kD transmembrane form of tumor necrosis factor alpha on activated CD4+ T cell clones provides a costimulatory signal for human B cell activation.

1993 ◽  
Vol 177 (6) ◽  
pp. 1575-1585 ◽  
Author(s):  
G Aversa ◽  
J Punnonen ◽  
J E de Vries
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cd4 T Cells ◽  
Plasma Membranes ◽  
Cd4 T Cell ◽  
Tnf Alpha ◽  
T Cell Clones ◽  
Cell Clones ◽  
Ige Synthesis

Interleukin 4 (IL-4) induces immunoglobulin (Ig)E and IgG4 synthesis in human B cells. In addition to IL-4, costimulatory signals provided by activated CD4+ T cells are required for productive IgG4 and IgE synthesis. Here we report that the 26-kD transmembrane form of tumor necrosis factor alpha (mTNF-alpha), which is rapidly expressed on CD4+ T cell clones after activation, contributes to the costimulatory signals resulting in IL-4-dependent Ig synthesis by B cells, including IgG4 and IgE production. mTNF-alpha expression was induced on T cell clones within 2 h after activation with concanavalin A. Peak expression was observed at 24 h, followed by a gradual decrease, but appreciable levels of mTNF-alpha were still detectable 72 h after activation. The presence of the 26-kD membrane form of TNF-alpha on activated T cell clones was confirmed by immunoprecipitation. Monoclonal antibodies (mAbs) recognizing mTNF-alpha, or the p55 TNF receptor, inhibited IgM, IgG, IgG4, and IgE synthesis induced by IL-4 and activated CD4+ T cell clones in cultures of highly purified surface IgD+ B cells. The anti-TNF-alpha mAbs also blocked Ig production in cultures in which the activated CD4+ T cell clones were replaced by their plasma membranes. Furthermore, pretreatment of the plasma membranes with anti-TNF-alpha mAbs strongly reduced their capacity to stimulate B cells to produce Ig in the presence of IL-4, indicating that the anti-TNF-alpha mAbs blocked the effects of mTNF-alpha. Anti-TNF-alpha mAbs did not affect IgM, IgG, IgG4, or IgE synthesis induced by anti-CD40 mAbs and IL-4 in the absence of CD4+ T cells, supporting the notion that the anti-TNF-alpha mAbs indeed interfered with the costimulatory, contact-mediated signal provided by T cells, or their membranes. Collectively these results indicate that mTNF-alpha, which is rapidly induced after activation of CD4+ T cells, participates in productive T-B cell interactions resulting in IL-4-induced Ig production. This is a novel property of the T cell membrane form of TNF-alpha.

Strong selection of virus-specific cytotoxic CD4+ T-cell clones during primary human cytomegalovirus infection

Blood ◽  
2006 ◽  
Vol 108 (9) ◽  
pp. 3121-3127 ◽  
Author(s):  
Ester M. M. van Leeuwen ◽  
Ester B. M. Remmerswaal ◽  
Mirjam H. M. Heemskerk ◽  
Ineke J. M. ten Berge ◽  
Rene A. W. van Lier
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Target Cells ◽  
Dependent Manner ◽  
T Cell Clones ◽  
Strong Selection ◽  
Cell Clones

Abstract To obtain insight into human CD4+ T cell differentiation and selection in vivo, we longitudinally studied cytomegalovirus (CMV)–specific CD4+ T cells after primary infection. Early in infection, CMV-specific CD4+ T cells have the appearance of interferon γ (IFNγ)–producing T-helper 1 (TH1) type cells, whereas during latency a large population of CMV-specific CD4+CD28– T cells emerges with immediate cytotoxic capacity. We demonstrate that CD4+CD28– T cells could lyse CMV antigen–expressing target cells in a class II–dependent manner. To clarify the clonal relationship between early and late CMV-specific CD4+ T cells, we determined their Vβ usage and CDR3 sequences. The T-cell receptor β (TCRβ) diversity in the early CMV-specific CD4+ T-cell population was high in contrast to the use of a very restricted set of TCRβ sequences in latent infection. T-cell clones found in the late CMV-specific CD4+ T-cell population could not be retrieved from the early CD4+ T-cell population, or were present only at a low frequency. The observation that dominant CMV-specific CD4+ clones during latency were only poorly represented in the acute phase suggests that after the initial control of the virus strong selection and/or priming of novel clones takes place in persistent infections in humans.

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