Preferential usage of the V beta 8 gene family by CD4-CD8-T cell lines derived from spleen

T cell receptor V beta gene expression in experimental herpes stromal keratitis

Our study examined T cell receptor (TCR) V beta mRNA expression in a murine model of experimental herpes simplex keratitis (HSK). We employed a polymerase chain reaction (PCR) technique to detect TCR V beta mRNA expression in the inoculated eyes of both HSK-susceptible and HSK-resistant mice at different time points after corneal inoculation with herpes simplex virus type 1 (HSV-1), followed by Southern blotting and densitometry analysis. In eyes from HSK-susceptible C.AL-20 mice, a more diverse TCR V beta transcript usage pattern was detected as compared with that seen in HSK-resistant C.B-17 mice. V beta 8 family members were expressed in both strains of mice at days 11, 14 and 21 post-inoculation. By densitometry, at day 11, the intensity of expression of V beta 8.2 and V beta 8.3 message was significantly greater in the eyes of C.AL-20 mice; V beta 8.1 was expressed only in C.B-17 mice. There were obvious differences in the TCR V beta expression between HSK-susceptible and HSK-resistant mice. The differences in the intensity of the message expressed by V beta 8 family members between the two strains could be correlated to previous experiments that showed V beta 8.1,2+ T cells as the main infiltrating cells in the corneas of HSK-susceptible mice by day 11 and 14 after challenge with HSV-1.

Induction of leukemia in mice using a radiation leukemia virus-induced cell line: a model system for studying oncogenic progression

Leukemogenesis induced by slowly transforming retroviruses is a multistep process which is difficult to dissect because of its long latency and the problem of distinguishing oncogenic from differentiative events. A method for leukemia induction in mice has been developed using a cell line isolated following in vitro infection with the slowly transforming murine radiation leukemia virus (RadLV). The CI-V13D cell line represents a lymphoid precursor cell type at an early stage in cell transformation and can develop subcutaneous tumors in irradiated syngeneic hosts but not in allogeneic mice even after sublethal irradiation. Selective growth in allogeneic (CBA/H) mouse thymus has been demonstrated, but this requires preirradiation of the recipient. Upon reisolation from CBA/H thymus, C1-V13D progeny clones displayed increased tumorigenic potential in comparison to the 'parental' CI-V13D cell line. Tumorigenicity was shown to increase with serial passage through thymus and electron micrographs of clones also revealed increased production of C-type retroviruses. This new model for oncogenic progression should be more amenable to analysis of early genetic changes occurring during replication of leukemia in the thymus.

Adoptive transfer of polyclonal and cloned cytolytic T lymphocytes (CTL) specific for mouse AIDS-associated tumors is effective in preserving CTL responses: a measure of protection against LP-BM5 retrovirus-induced immunodeficiency

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.

A murine retrovirus induces proliferation of unique lymphoid cell lines expressing T-cell-receptor structures utilizing common variable region alpha and beta chain genes

A murine radiation leukemia virus (RadLV) has been shown to induce in vitro proliferation of an unusual subset of lymphoid cells from spleen. They have the unusual property of expressing CD3/T-cell receptor alpha and beta chains (TCR-alpha beta) in the absence of other T-cell markers such as Thy-1, CD4, and CD8. Cell lines induced in two mouse strains with RadLV produced by the C6VL/1 thymoma all specifically utilize common V alpha 3 and V beta 8.2 variable region genes in the formation of a TCR structure. Each of these cell lines has now been found to express both class I and class II major histocompatibility antigens and the beta 2 integrin specific for spleen dendritic cells. Analysis of functional properties of these cells has revealed a subset that can endocytose proteins and function alone as antigen-presenting cells. They have therefore been called D-T cells (i.e., dendritic cells expressing TCR-alpha beta). A retroviral-driven event has been implicated in the proliferation of dendritic-like cells expressing a common TCR epitope.

Characterization of alpha beta+ CD4- CD8- CTL lines isolated from mixed lymphocyte cultures of adult mouse spleen cells

Several CD4- CD8- and CD4- CD8+ T cell lines and clones have been isolated from the same mixed lymphocyte cultures. They express the alpha beta T cell receptor, are CD3+, V beta 8- and heat stable antigen-, and exhibit highly specific cytolytic activity mapping to H2Db. However, monoclonal antibody against H2Db failed to block lysis by CD4- CD8- cytotoxic T lymphocytes (CTL). One possible explanation is that the "double negative" cytotoxic T lymphocytes may recognize H2Db in the context of other class I molecules (Qa/Tla). CD4 and CD8 could be detected on some lines cloned in high concentrations of EL4 supernatant and the cell surface expression was influenced by growth conditions. The alpha beta+ CD4- CD8- CTL described in this report are clearly different from the so-called "autoimmune double negatives" which suggests a function for them in normal immune responses.

Preferential expression of a common T cell receptor structure by T cells induced to proliferate in vitro with a murine retrovirus

We have successfully isolated continuous T cell lines from murine spleen which have been induced to proliferate after in vitro exposure to the murine leukemia virus RadLV. Cell lines isolated from several strains of mice have an "immature" phenotype and are immortalized CD4- CD8- CD3+ cell lines. Cell lines of similar phenotype have now been derived from many individual mice, after spleens have been infected with two different RadLV viruses, a leukemogenic and a nonleukemogenic isolate. Among cell lines induced with RadLV/C6VL, an unusually high proportion of cells was found to bind the 124-40 anticlonotypic antibody specific for the alpha beta TCR expressed by C6VL/1 cells which produces RadLV/C6VL. This was not reflected in cell lines induced with the RadLV/V13 isolate nor in various lymphocyte subsets freshly isolated from normal mice, or induced to proliferate in culture. Cells expressing a common TCR structure would appear to be appropriate targets for in vitro proliferation and transformation induced by RadLV.

Identification of class I H-2Db molecules primarily expressed by B lymphocytes in murine spleen

Evidence is presented which supports the phenomenon of heterogeneity amongst H-2Db-encoded Class I molecules. Two monoclonal antibodies (MoAb) called H141-31 and B22-249 were used in these studies. Both bind to the 'private' H-2.2 site of H-2Db-encoded molecules, but the binding of B22-249 is determined by carbohydrate moieties, whereas H141-31 appears to bind to a protein-defined epitope. Some H-2Db molecules, identified by the H141-31 MoAb, are primarily expressed on B lymphocytes and not T lymphocytes in spleen. The number of H-2Db molecules which bind H141-31 on B cells was also found to be three- to four-fold less than the number which bound the B22-249 MoAb. B cells of two mutant strains of mice, B6-C.H-2bm13 and B6-C.H-2bm14 which harbour very few nucleotide changes in the H-2Db gene, also show marked reduction in the binding of both antibodies. This suggests that a single common gene encodes both target molecules and that post-translational modifications such as differential glycosylation may account for heterogeneity amongst H-2Db molecules. This would explain the presence of the different H-2Db molecules defined here. It follows that differences in glycosylation evidently occur both within the B cell population, since H141-31 binds to only a subset of H-2Db molecules on B cells, and between T and B lymphocytes, since resting T cells do not bind H141-31 MoAb.