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Biomedical subjects

R I Fox

Publications and source records attributed to R I Fox.

At least 127 records · Page 7Linked to original sources
PubMed1982

Synovial fluid lymphocytes differ from peripheral blood lymphocytes in patients with rheumatoid arthritis.

Peripheral blood (PBL) and synovial fluid lymphocytes (SFL) from 12 patients with rheumatoid arthritis (RA) were analyzed using monoclonal antibodies that detect specific T cell surface antigens (OKT3, OKT4, OKT8, SC1) and antigens associated with lymphocyte activation (anti-Ia, OKT10, B3/25). RA patients' PBL contained 1010 +/- 74 OKT4+ and 401 +/- 62 OKT8+ cells/mm3 (ratio OKT4+/OKT8+ = 2.4 +/- 0.3). In contrast, SFL from these patients exhibited a significantly different proportion of T cell subsets (ratio OKT4+/OKT8+ = 1.1 +/- 0.5) (p less than 0.0001) with 630 +/- 180 OKT4+ and 595 +/- 225 OKT8+ cells/mm3. Synovial fluid contained significantly more activated T cells based on the presence of Ia-positive T cells (19 +/- 5%) and reactivity with antibody OKT10 (49 +/- 7%) compared with RA-PBL (8 +/- 3% Ia-positive T cells and 13 +/- 6% OKT10+). Compared with RA-PBL, normal PBL contained an elevated number of OKT8+ cells (610 +/- 48/mm3), a similar number of OKT4+ cells (1040 +/- 86/mm3), and a lower percentage of activated lymphocytes (3 +/- 2% Ia-positive T cells and 10 +/- 8% OKT10+ cells). SFL, RA-PBL, and normal PBL all showed less than 3% cells reactive with antibody B3/25 (anti-transferrin receptor antibody), a marker found on in vitro activated T cells. These findings demonstrate that the lymphocytes at the site of inflammation differ significantly from the lymphocytes present in the peripheral blood of the same patients. RA patients had a small but significant decrease in the number of OKT8+ cells/mm3 compared with normal PBL (p less than 0.01), suggesting that this lymphocyte subset may home to synovial tissues, where it becomes activated.

Antibodies, Monoclonal↗
PubMed1981

Solid-phase selection of human T lymphocyte subpopulations using monoclonal antibodies.

This report describes a novel solid-phase technique for the positive selection of human T lymphocyte subsets labeled by indirect immunofluorescence with monoclonal anti-bodies. Fluorescein labeled normal human T cells or a T cell line were fractionated on plastic culture dishes precoated with affinity chromatography purified anti-fluorescein antibodies. Cell binding was specific for fluorescein, and was both time and temperature dependent. Bound cells were eluted at 37 degrees C with fluorescein-L-lysine. The eluted cells were enriched with highly viable and functional human T cell subsets. Thus Leu3 monoclonal antibody selected cells were shown to provide helper activity in the pokeweed mitogen induced IgM and IgG immunoglobulin secretory response of autologous B cells. The Leu2 antibody selected T cells suppressed both IgM and IgG secretory responses. In addition, studies with the monoclonal antibody 1G11, which binds to an antigen expressed on acute lymphocytic leukemia (T-ALL) cells and the T-ALL derived cell line RPMI-8402, demonstrated that this solid-phase technique can be used to select for cells which are present at low frequencies in a mixed population. It thus provides a simple and reproducible means for the preparative isolation of lymphocyte subsets associated with autoimmune and neoplastic disease for functional and biochemical analysis.

Animals↗
PubMed1981

Fractionation of human lymphocyte subpopulations on immunoglobulin coated Petri dishes.

This report describes a simple solid-phase technique for the positive selection of lymphocytes labeled with fluoresceinated antibodies. B lymphocytes were labeled with fluoresceinated anti-human Ig or monoclonal anti-human Ia (L243), and then were bound to plastic culture dishes coated with affinity purified goat anti-fluorescein specific antibody. Bound cells were eluted at 37 degrees C with 1 mM fluorescein-L-lysine phosphate-buffered saline. Functionally the eluted Ig positive cells responded to pokeweed mitogen (PWM) by in vitro secretion of IgM, as measured by radioimmunoassay of culture supernatants. The secretion of IgM was dependent on the addition of T lymphocytes. Moreover, the isolated B cells were functionally receptive to 'help' and 'suppression' by T cells with and without Fc receptors for IgG respectively. T cell subsets were fractionated on plastic culture dishes coated with heat aggregated rabbit or human IgG. the non-bound cells (enriched T(gamma-)) provided collaborative 'help' in the PWM induced IgM secretion response by human B lymphocytes. The bound cells (enriched T(gamma+)) eluted with 0.01 M EDTA in phosphate-buffered saline, suppressed IgM secretion. This method can be adapted to fractionate subsets of lymphocytes for which a fluoresceinated antibody is available. For routine functional studies, the isolation of cell types with conventional or monoclonal antibodies does not require the use of a fluorescence activated cell sorter, but only an antifluorescein labeled Petri dish. In conclusion, a rapid solid-phase technique enables us to prepare enriched populations of functionally active lymphocytes.

Animals↗
PubMed1981

Studies of a human T lymphocyte antigen recognized by a monoclonal antibody.

A monoclonal antibody (designated L17F12) detects an antigen present on 95-100% of human peripheral T lymphocytes, the majority of thymocytes, and acute lymphocytic leukemia T cells but not B cells, B-cell lines, or monocytes. Examination of frozen tissue sections by the immunoperoxidase method revealed that the cells expressing this antigen were found predominantly in the medulla of thymus and in T-cell zones of lymph node and spleen. The antigen recognized by L17F12 was associated with a cell-surface glycoprotein of 67,000 daltons. L17F12 was used to isolate this molecule from human thymocytes, normal peripheral T cells, leukemic T cells, and T-cell lines. Expression of this antigen on normal T cells was not diminished by prolonged exposure in vitro to various T-cell stimuli. In the absence of complement, L17F12 bound to T cells without altering proliferative functions, thus enabling rapid purification of functionally intact T cells. In the presence of complement, L17F12 was cytolytic for T cells, providing the basis for depletion of T cells from heterogeneous populations. These data suggest that the monoclonal antibody L17F12 recognizes a specific T-cell differentiation protein. This antibody will be useful in studies of the human immune system.

Animals↗
PubMed1981

T lymphocyte-mediated cytotoxicity against autologous EBV-genome-bearing B cells.

We have stimulated human peripheral blood lymphocytes in vitro with autologous EBV-infected or noninfected B cells. A cytotoxic response was obtained only when virally infected cells were used. The activity of the effector cells was restricted by the major histocompatibility complex and was directed against EBV-genome-bearing targets. The highest cytolytic response was obtained when lymphocytes of individuals previously exposed to the virus (EBV-VCA positive) were used. Lymphocytes of noninfected donors (EBV-VCA negative) gave a low response; the relative frequency of their effector cells was at least 4-fold lower. Lymphocytes of newborns did not respond. The cytotoxic activity was mediated by T lymphocytes of the cytotoxic/suppressor subset, as determined by cytofluorographic analysis and antibody plus complement-mediated lysis, using monoclonal antibodies to human lymphocyte surface antigen.

Antibodies↗
PubMed1981

Definition of the high-risk acute lymphoblastic leukemia patient by immunological phenotyping with monoclonal antibodies.

An accurate method of classification of the surface membrane characteristics of blast cells from patients with acute lymphoblastic leukemia would allow a more definitive study of the nature of this disease. Monoclonal antibodies have been produced to the surface antigens of leukemic blasts form a patient with high-risk acute lymphoblastic leukemia. Two antibodies of interest were obtained from this immunization. These two, in combination with a monoclonal antibody with anti-Ia specificity, have been used to obtain surface phenotypes for patients with childhood acute lymphoblastic leukemia. Preliminary results indicate that the definition of a high-risk group, using these antibodies, possible.

Acute Disease↗
PubMed1979

A human thymus-leukemia antigen defined by hybridoma monoclonal antibodies.

A series of mouse hybridomas producing monoclonal antibodies against human acute lymphocytic leukemia (ALL) cells was generated and screened for tumor specificity. Among 1200 primary cultures, 60 produced an antibody that could distinguish between the immunizing leukemia cells and an isologous B lymphoblastoid cell line. Of these, two produced an antibody that detects an antigen expressed preferentially on ALL cells and on a subpopulation of normal cells found in the cortex of the thymus. Other normal human lymphoid cells from lymph nodes, spleen, bone marrow, and peripheral blood express only low levels of this antigen. High levels of this "thymus-leukemia" antigen were found on T-ALL cells, T-ALL-derived cell lines, and some "null" ALL cells. By contrast, B-cell leukemias, B lymphoblastoid cell lines, and normal and malignant myeloid cells contain either low or undetectable amounts of this antigen. The thymus-leukemia antigen has been isolated from the membranes of leukemia cells by detergent solubilization and subsequent immunoprecipitation with the monoclonal antibody. Preliminary biochemical characterization shows the antigen to be associated with a polypeptide of Mr approximately 28,000.

Antibody Specificity↗
PubMed1972

Synthesis of viral ribonucleic acid during restricted adenovirus infection.

The mechanism by which simian virus 40 converts the abortive adenovirus type 7 infection of monkey cells into an efficient lytic infection has been investigated. Analysis of ribonucleic acid (RNA) synthesis during unenhanced and enhanced infection of monkey cells has shown that adenovirus RNA synthesized in the abortive infection contains both "early" and "late" sequences. In hybridization competition experiments, early adenovirus RNA from human cells prevented the hybridization of only 20% of the adenovirus RNA transcribed in unenhanced infection. Further, the RNA from unenhanced cells was able to completely block the hybridization of RNA synthesized during enhanced infection. Finally, virus-associated RNA, which is a late RNA transcribed in lytic adenovirus infection, is also produced in the unenhanced infection. An accompanying paper describes a marked deficiency in adenoviral capsid protein synthesis in the unenhanced infection. We conclude that RNA sequences, which are sufficient to code for the synthesis and assembly of structural proteins of adenovirus, are transcribed but are not efficiently translated in the unenhanced adenovirus infection of monkey cells.

Adenoviridae↗
PubMed1971

Components of adenovirus-simian virus 40 hybrid viruses.

The DNA and protein components of the adenovirus 7-simian virus (SV)40 hybrid virus "E46(+)" have been investigated. The Ad.7-SV40 hybrid DNA genome could be distinguished from nonhybrid Ad. 7 genome on the basis of its molecular weight in an alkaline sucrose gradient. The hybrid genome could also be separated from nonhybrid adenovirus 2 DNA when purified transcapsidant adenovirus 2(+t7) (Ad.7-SV40 DNA within an Ad.2 capsid) was studied. The presence and amount of SV40 DNA in the hybrid virus genome was determined by DNA-RNA hybridization. The results presented suggest: (i) that about 10% of the particles in the E46(+) preparations contained SV40 DNA covalently linked to adenovirus DNA; (ii) that the hybrid virus genome has a molecular weight 10-12% lower than that of nonhybrid virus, consistent with a deletion of adenovirus DNA; and (iii) that the hybrid virus contained only 40-50% of a total SV40 genome. The protein components of the Ad.7-SV40 hybrid virus were examined by acrylamide gel electrophoresis in sodium dodecyl sulfate. No significant quantitative or qualitative differences between the proteins of hybrid and nonhybrid adenovirus were demonstrated.

Adenoviridae↗