Persistence of immunoglobulin heavy chain/c-myc recombination-positive lymphocyte clones in the blood of human immunodeficiency virus-infected homosexual men.

We studied blood lymphocytes of human immunodeficiency virus (HIV)-seropositive and -negative homosexual men for the presence of T(8;14) translocations that recombine c-myc and immunoglobulin heavy-chain (IgH) mu/IgH alpha switch regions. Clones with T(8;14) translocations were detected in 10.5% (12/114) of the HIV-positive and in 2.0% of the 99 uninfected patients. The majority of recombinations were found at a single time point only. Four patients, however, harbored multiple (up to four) and persistent (up to 9 years) translocation-positive cell clones. No correlation between the presence of these aberrant lymphocytes and a later lymphoma could be established. The exon 1/intron 1 region of the recombined c-myc was investigated for the presence of point mutations and these were found in the nonpersistent clones. Additional alterations detected in these clones included duplications and a deletion in the c-myc gene. The pattern of base substitution indicates that they were introduced after the translocation event.

Growth factors can enhance lymphocyte survival without committing the cell to undergo cell division.

Growth factors have been defined by their ability to promote the proliferative expansion of receptor-bearing cells. For example, antigen-activated T cells expressing the alpha beta gamma form of the interleukin 2 (IL-2) receptor will proliferate in response to IL-2. In contrast, resting T cells, which express the IL-2 receptor beta and gamma chains, do not proliferate in response to IL-2. We demonstrate that the survival of resting T cells following gamma irradiation is greatly enhanced by pretreatment with IL-2. The radioprotective effect of IL-2 is dose dependent, does not result from the induction of cell proliferation, and does not require expression of the IL-2 receptor alpha chain. Thus, the beta gamma IL-2 receptor expressed on resting T cells can transduce signals that promote cell survival without committing the T cell to undergo cell division. IL-4 and IL-7, but not IL-1, IL-3, or IL-6, were also found to enhance the survival of quiescent T cells following gamma irradiation. Thus, certain growth factor-receptor interactions can serve to maintain cell viability in a manner that is independent of their ability to initiate or maintain cell proliferation. These data may have important implications for the use of growth factors in patients being treated with radiation and/or chemotherapy.

Cytotoxic T-lymphocyte clones from different patients display limited T-cell-receptor variable-region gene usage in HLA-A2-restricted recognition of the melanoma antigen Melan-A/MART-1.

To determine whether T-cell-receptor (TCR) usage by T cells recognizing a defined human tumor antigen in the context of the same HLA molecule is conserved, we analyzed the TCR diversity of autologous HLA-A2-restricted cytotoxic T-lymphocyte (CTL) clones derived from five patients with metastatic melanoma and specific for the common melanoma antigen Melan-A/MART-1. These clones were first identified among HLA-A2-restricted anti-melanoma CTL clones by their ability to specifically release tumor necrosis factor in response to HLA-A2.1+ COS-7 cells expressing this tumor antigen. A PCR with variable (V)-region gene subfamily-specific primers was performed on cDNA from each clone followed by DNA sequencing. TCRAV2S1 was the predominant alpha-chain V region, being transcribed in 6 out of 9 Melan-A/MART-1-specific CTL clones obtained from the five patients. beta-chain V-region usage was also restricted, with either TCRBV14 or TCRBV7 expressed by all but one clone. In addition, a conserved TCRAV2S1/TCRBV14 combination was expressed in four CTL clones from three patients. None of these V-region genes was found in a group of four HLA-A2-restricted CTL clones recognizing different antigens (e.g., tyrosinase) on the autologous tumor. TCR joining regions were heterogeneous, although conserved structural features were observed in the complementarity-determining region 3 sequences. These results indicate that a selective repertoire of TCR genes is used in anti-melanoma responses when the response is narrowed to major histocompatibility complex-restricted antigen-specific interactions.

Blockade of T- and B-lymphocyte development by antibody to the gamma c subunit of the receptors for interleukins 2, 4, and 7.

Cytokines are important regulators of hematopoesis. Mutations in gamma c, which is a subunit shared by the receptors for interleukin (IL) 2, IL-4, and IL-7, have been causally associated with human X chromosome-linked severe combined immunodeficiency disease. This finding indicates a mandatory role for cytokine receptor signaling at one or more stages of lymphocyte development. To evaluate the cellular level at which gamma c is critical for lymphopoiesis, the effect of monoclonal antibodies to gamma c on the capacity of syngeneic bone marrow cells to reconstitute the hematopoietic compartment of lethally irradiated recipient mice was examined. We show that monoclonal antibody to gamma c blocked lymphocyte development at or before the appearance of pro-B cells and prior to or at the seeding of the thymus by precursor cells while erythromyeloid cell development was normal. These results suggest that one level of lymphocyte development that requires gamma c is a point in hematopoietic cell differentiation near the divergence of lymphopoiesis and erythromyelopoesis.

Mouse mesenchymal stem cells inhibit high endothelial cell activation and lymphocyte homing to lymph nodes by releasing TIMP-1.

Mesenchymal stem cells (MSC) represent a promising therapeutic approach in many diseases in view of their potent immunomodulatory properties, which are only partially understood. Here, we show that the endothelium is a specific and key target of MSC during immunity and inflammation. In mice, MSC inhibit activation and proliferation of endothelial cells in remote inflamed lymph nodes (LNs), affect elongation and arborization of high endothelial venules (HEVs) and inhibit T-cell homing. The proteomic analysis of the MSC secretome identified the tissue inhibitor of metalloproteinase-1 (TIMP-1) as a potential effector molecule responsible for the anti-angiogenic properties of MSC. Both in vitro and in vivo, TIMP-1 activity is responsible for the anti-angiogenic effects of MSC, and increasing TIMP-1 concentrations delivered by an Adeno Associated Virus (AAV) vector recapitulates the effects of MSC transplantation on draining LNs. Thus, this study discovers a new and highly efficient general mechanism through which MSC tune down immunity and inflammation, identifies TIMP-1 as a novel biomarker of MSC-based therapy and opens the gate to new therapeutic approaches of inflammatory diseases.

Immunization with a circumsporozoite epitope fused to Bordetella pertussis adenylate cyclase in conjunction with cytotoxic T-lymphocyte-associated antigen 4 blockade confers protection against Plasmodium berghei liver-stage malaria

The adenylate cyclase toxoid (ACT) of Bordetella pertussis is capable of delivering its N-terminal catalytic domain into the cytosol of CD11b-expressing professional antigen-presenting cells such as myeloid dendritic cells. This allows delivery of CD8+ T-cell epitopes to the major histocompatibility complex (MHC) class I presentation pathway. Recombinant detoxified ACT containing an epitope of the Plasmodium berghei circumsporozoite protein (CSP), indeed, induced a specific CD8+ T-cell response in immunized mice after a single application, as detected by MHC multimer staining and gamma interferon (IFN-gamma) ELISPOT assay. This CSP-specific response could be significantly enhanced by prime-boost immunization with recombinant ACT in combination with anti-CTLA-4 during the boost immunization. This increased response was accompanied by complete protection in a number of mice after a challenge with P. berghei sporozoites. Transient blockade of CTLA-4 may overcome negative regulation and hence provide a strategy to enhance the efficacy of a vaccine by amplifying the number of responding T cells.

Blood group antigens & antibodies as applied to blood transfusion.

Includes bibliographical references.

Clinical pathology and transfusion medicine guide /

"February 1997"--p. [4] of cover.

Die transfusion des blutes und einsprützung der arzeneyen in die adern : historisch und in rücksicht auf die practische heilkunde bearbeitet /

Mode of access: Internet.

Experimentelle Untersuchungen zur Physiologie und Pathologie der Embolie, Transfusion und Blutmenge.

Reprinted from Virchow's Archiv für pathologische Anatomie, v. 27-29.

Post-transfusion Hepatitis B and Hepatitis non-A/non-B : report to the Illinois General Assembly

The report, which is mandated by Public Act 80-753 describes the great strides made since the early 1970s in preventing viral hepatitis following blood transfusion.

Hemorrhage and transfusion; an experimental and clinical research,

Bibliography: p. [537]-549.

Mechanisms of B and T lymphocyte accumulation in tumor-draining lymph nodes

Thesis (Master's)--University of Washington, 2016-06