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Abstract
My laboratory investigations have been driven by an abiding interest in understanding the consequences of genetic rearrangement in evolution and disease, and in using viruses to elucidate fundamental mechanisms in biology. Starting with bacteriophages and moving to the retroviruses, my use of the tools of genetics, molecular biology, biochemistry, and biophysics has spanned more than half a century-from the time when DNA structure was just discovered to the present day of big data and epigenetics. Both riding and contributing to the successive waves of technology, my laboratory has elucidated fundamental mechanisms in DNA replication, repair, and recombination. We have made substantial contributions in the area of retroviral oncogenesis, delineated mechanisms that control retroviral gene expression, and elucidated critical details of the structure and function of the retroviral enzymes-reverse transcriptase, protease, and integrase-and have had the satisfaction of knowing that the fundamental knowledge gained from these studies contributed important groundwork for the eventual development of antiviral drugs to treat AIDS. While pursuing laboratory research as a principal investigator, I have also been a science administrator-moving from laboratory head to department chair and, finally, to institute director. In addition, I have undertaken a number of community service, science-related "extracurricular" activities during this time. Filling all of these roles, while being a wife and mother, has required family love and support, creative management, and, above all, personal flexibility-with not too much long-term planning. I hope that this description of my journey, with various roles, obstacles, and successes, will be both interesting and informative, especially to young female scientists.
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Affiliation(s)
- Anna Marie Ann Skalka
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111;
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Billich A, Billich S, Rosenwirth B. Assay Systems for HIV-1 Proteinase and Their Use for Evaluation of Inhibitors. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029100200201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- A. Billich
- Sandoz Forschungsinstitut GmbH, Department of AntiRetroviral Therapy, Brunnerstr. 59, A-1235 Vienna, Austria
| | - S. Billich
- Sandoz Forschungsinstitut GmbH, Department of AntiRetroviral Therapy, Brunnerstr. 59, A-1235 Vienna, Austria
| | - B. Rosenwirth
- Sandoz Forschungsinstitut GmbH, Department of AntiRetroviral Therapy, Brunnerstr. 59, A-1235 Vienna, Austria
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Nair MP, Schwartz SA. Reversal of human immunodeficiency virus type 1 protein-induced inhibition of natural killer cell activity by alpha interferon and interleukin-2. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2000; 7:101-5. [PMID: 10618286 PMCID: PMC95831 DOI: 10.1128/cdli.7.1.101-105.2000] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A recombinant fusion peptide, Env-Gag, derived from the human immunodeficiency virus type 1 (HIV-1) genome corresponding to a defined portion of the envelope (Env) and internal core (Gag) proteins was examined for immunoregulatory effects on the cytotoxic activity of natural killer (NK) cell-enriched, large granular lymphocytes (LGL) from healthy donors. Percoll-separated, NK cell-enriched LGL precultured for 24 h with Env-Gag at 10- and 50-ng/ml concentrations, which significantly stimulated lymphocyte proliferation, caused significant suppression of NK cell activity. Denatured Env-Gag did not cause any effect on the NK cell activity of LGL. Two other control peptides, one derived from the Escherichia coli vector used to clone the HIV Env-Gag fusion peptide and the other derived from a non-HIV-1 viral antigen (rubeola virus), did not produce any observable effect on the NK cell activity of LGL, demonstrating the specificity of the effect produced by Env-Gag. Subsequent treatment of LGL with alpha interferon (IFN-alpha) or interleukin 2 (IL-2) alone partially reversed the Env-Gag-induced suppression of NK cell activity. However, LGL treated with both IFN-alpha and IL-2 completely reversed the suppression of NK cell cytotoxicity by Env-Gag. The combined effect of IFN-alpha and IL-2 in enhancing NK cell activity may provide a novel therapeutic approach to the restoration of depressed NK cell activity observed in HIV-infected patients.
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Affiliation(s)
- M P Nair
- Department of Medicine and Microbiology, Division of Allergy, Immunology and Rheumatology, and Buffalo General Hospital, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, New York 14203, USA.
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Nair MP, Schwartz SA, Polasani R, Hou J, Sweet A, Chadha KC. Immunoregulatory effects of morphine on human lymphocytes. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1997; 4:127-32. [PMID: 9067644 PMCID: PMC170490 DOI: 10.1128/cdli.4.2.127-132.1997] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
It is now well established that parenteral drug abuse is a significant risk factor for contracting human immunodeficiency virus type 1 (HIV-1) infection and subsequently developing AIDS. Earlier studies have shown that morphine can modulate various immune responses and therefore support the premise that morphine is a cofactor in susceptibility to and progression of HIV infection. Dysregulation of interferon (IFN) production, nonspecific apoptosis of T cells, and the immune response to soluble HIV gene products have been associated with potential mechanisms of pathogenesis in HIV disease. The present study was undertaken to examine the immunomodulatory role of morphine on HIV protein-induced lymphocyte proliferative responses, Sendai and Newcastle disease virus-induced alpha IFN (IFN-alpha) and IFN-beta production by lymphocytes and fibroblast cells, respectively, and induction of apoptosis of normal lymphocytes in vitro. Our results demonstrate that HIV protein-induced human lymphocyte proliferative responses were significantly inhibited by morphine in a dose-dependent manner. Furthermore, morphine significantly inhibited both IFN-alpha and IFN-beta production by normal lymphocytes and fibroblasts but induced apoptosis of normal lymphocytes. Inhibition of IFN-alpha production by morphine could be reversed by the opiate receptor antagonist naloxone. This suggests that the immunomodulatory effects of morphine are mediated through the opioid receptor. These studies support a role of morphine as a cofactor in the pathogenesis of HIV infection and describe some of the possible pathologic mechanisms which underlie the immunoregulatory effects of morphine.
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Affiliation(s)
- M P Nair
- Department of Medicine, Buffalo General Hospital, State University of New York at Buffalo 14203, USA
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Nair MP, Kumar NM, Kronfol ZA, Saravolatz LA, Pottathil R, Greden JF, Schwartz SA. Selective effect of alcohol on cellular immune responses of lymphocytes from AIDS patients. Alcohol 1994; 11:85-90. [PMID: 8204207 DOI: 10.1016/0741-8329(94)90048-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this study we examined the in vitro effects of alcohol on the proliferative responses of lymphocytes from healthy donors and AIDS patients to a recombinant fusion peptide, env-gag, corresponding to portions of the gp41 envelope (env) and internal core (gag) proteins of HIV. The effects of alcohol (ETOH) on the natural killer (NK) cell activities of lymphocytes from healthy donors and patients with AIDS were also investigated. Peripheral blood mononuclear cells from both normal donors and AIDS patients produced significant levels of lymphocyte proliferative responses to the HIV env-gag peptide; however, these responses were significantly higher in patients with AIDS, showing the specificity of the response. The env-gag-induced proliferative responses of lymphocytes from normal subjects were significantly suppressed when cultures contained only higher levels of ETOH (0.2% and 0.3%), whereas ETOH even at a lower level (0.1%) produced significant suppression of the env-gag-induced proliferation of lymphocytes only from AIDS patients. Direct addition of ETOH at concentrations of 0.1%, 0.2%, and 0.3% to cultures of lymphocytes from normal donors and NK target cells did not produce significant suppression of NK cell activities. However, ETOH at concentrations of 0.2% and 0.3% significantly suppressed the NK activities of lymphocytes from AIDS patients, and the suppressive effect was observed at all E:T cell ratios examined. Control peptide from the Escherichia coli expression vector did not produce any significant effect on lymphocyte proliferative responses or NK activity of both normal donors and AIDS patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M P Nair
- Department of Medicine, State University of New York at Buffalo
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Marczinovits I, Boros I, el Jarrah F, Füst G, Molnár J. Expression in Escherichia coli and in vitro processing of HIV-1 p24 fusion protein. J Biotechnol 1993; 31:225-32. [PMID: 7764303 DOI: 10.1016/0168-1656(93)90163-h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recombinant HIV-1 p24/p25 gag proteins were obtained from Escherichia coli using a cleavable fusion strategy. The fusion protein contains 280 amino acid residues of staphylococcal Protein A and 317 amino acid residues of p24/p25 flanking with the recognition/cleavage sequences for HIV protease. Fusion protein expressed under the control of lambda phage promoter PR was purified by IgG-Sepharose affinity chromatography. The p24/p25 part of the fusion protein was released by recombinant HIV protease in vitro. After a second IgG-Sepharose affinity chromatography, the purified p24/p25 proteins were obtained in milligram quantities. The HIV-1 p24/p25 protein displayed antigenicity similar to those of native counterparts confirmed by Western blot assays and the Abbott antigen test.
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Affiliation(s)
- I Marczinovits
- Institute of Microbiology, Albert Szent-Györgyi Medical University, Szeged, Hungary
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Haaheim LR, Maskell JP, Mascagni P, Coates AR. Fine molecular specificity of linear and assembled antibody binding sites in HIV-1 p24. Scand J Immunol 1991; 34:341-50. [PMID: 1715604 DOI: 10.1111/j.1365-3083.1991.tb01555.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A set of seven murine monoclonal antibodies were generated against a chemically synthesized 11-kDa 104-mer peptide covering the C-terminal residues 270-373 of the p24 gag protein (HIV-1BRU strain). All monoclonal antibodies recognized HIV-1IIIB infected MOLT3 cells by fluorescence and gave positive Western blot signals with viral gag peptides (p55 and/or p24). Oligopeptide binding regions were located with competitive enzyme-linked immunosorbent assays. Detailed epitope scanning analyses (the Geysen technique) were performed by serological testing of the monoclonal antibodies against 99 overlapping hexapeptides which corresponded to the entire 104-mer region. The antibodies bound to p24 peptide sequences located within the 275-293 and 351-368 regions. One antibody (LH104-B) which reacted with residues 357-362 bound to p55 alone. In contrast, another antibody (LH104-I), which recognized the residues 358-363, i.e. with five out of six residues in common with antibody LH104-B for its epitope region, reacted exclusively with p24. At least two of the antibodies (LH104-C and -A) which bound to p24 alone, apparently recognized conformational epitopes. They gave positive reactions with the regions 288-293/351-356 and 284-289/351-356, respectively. This work shows that chemical synthesis of large peptides is a viable alternative approach to immunochemical studies of viral proteins.
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Affiliation(s)
- L R Haaheim
- Department of Microbiology and Immunology, Gade Institute, University of Bergen, Norway
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Laboratory Diagnosis of Retroviral Infections. Dermatol Clin 1991. [DOI: 10.1016/s0733-8635(18)30395-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Siitari H, Turunen P, Schrimsher J, Nunn M. New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay. J Clin Microbiol 1990; 28:2022-9. [PMID: 2121790 PMCID: PMC268097 DOI: 10.1128/jcm.28.9.2022-2029.1990] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-amino-acid sequence from a highly conserved region of the HIV-1 gp41 envelope protein. This recombinant antigen enabled the detection of antibodies to both gag and env gene products. When this assay was compared with a commercially available recombinant enzyme-linked immunoabsorbent assay (ELISA) by using four quality-control panels, the TR-FIA detected all 20 positive specimens, while the recombinant ELISA detected only 16 of them. This increased sensitivity could be demonstrated directly by the assay of dilution series of HIV-1-positive sera. The analysis of two seroconversion panels by TR-FIA and six ELISAs showed that TR-FIA allowed detection of antibody in infected individuals 16 days earlier than the other assays did. In addition to being highly sensitive, the assay was highly specific; of the 57 samples shown to be repeatedly positive by ELISA but known to be HIV-1 negative by Western immunoblot analysis, only 1 sample reacted positively in this assay. The specificity of the assay was 99.9% when 1.054 random serum specimens were tested.
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Affiliation(s)
- H Siitari
- Wallac Molecular Biology Laboratory, Turku, Finland
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Robinson JE, Holton D, Liu J, McMurdo H, Murciano A, Gohd R. A novel enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to HIV-1 envelope glycoproteins based on immobilization of viral glycoproteins in microtiter wells coated with concanavalin A. J Immunol Methods 1990; 132:63-71. [PMID: 2202766 DOI: 10.1016/0022-1759(90)90399-g] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have developed a novel method that greatly simplifies the preparation of solid-phase HIV-1 envelope glycoproteins for use in an ELISA that detects serum antibodies to HIV envelope antigens. This method utilizes concanavalin A absorbed to wells of microtiter plates to affinity immobilize detergent-solubilized viral glycoproteins released in culture fluids of HIV-1 infected cell lines grown in serum free medium. Antibodies binding to ConA-immobilized viral antigens are detected by peroxidase-conjugated antibodies and appropriate enzyme substrates. Unlike most commercial HIV ELISAs, which utilize gp120 depleted-purified virus as the source of antigens and thus favor detection of antibodies to core antigens, the ConA envELISA is highly sensitive for detecting antibodies to native gp120, as evidenced by the strong reactivity of gp120-specific human monoclonal antibodies. Our results also suggest that representation of gp41 in the assay varies and depends on which virus infected cell lines are used for antigen production. Since this assay accurately identified 14 HIV-1 antibody positive patient sera and no false positives were detected among 16 HIV-1 negative sera, the ConA envELISA shows promise as an inexpensive assay for the serologic diagnosis of HIV infections.
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Affiliation(s)
- J E Robinson
- Department of Pediatrics, Louisiana State University School of Medicine, New Orleans 70112
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Windheuser MG, Tegtmeier GE, Wood C. Use of TrpE/Gag fusion proteins to characterize immunoreactive domains on the human immunodeficiency virus type 1 core protein. J Virol 1989; 63:4064-8. [PMID: 2474676 PMCID: PMC251008 DOI: 10.1128/jvi.63.9.4064-4068.1989] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The human immunodeficiency virus (HIV) p24 core protein is one of the most immunogenic of HIV structural proteins. Infected individuals develop high titers of antibodies against p24 early in infection, which makes anti-p24 antibodies important serological markers. However, despite the clinical importance of the anti-p24 response, no systematic study to characterize the antigenic domains on the p24 protein has been reported. We report here on the use of 12 overlapping fragments of the HIV type 1 p24 protein, synthesized in bacteria as TrpE/Gag fusion proteins, to identify at least two and possibly three antigenic domains on the p24 protein. In addition, we note that different HIV-seropositive sera exhibited different patterns of reactivity with the p24 domains presented on our fusion proteins.
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Affiliation(s)
- M G Windheuser
- Department of Microbiology, University of Kansas, Lawrence, Kansas 66045
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Kolbe HV, Jaeger F, Lepage P, Roitsch C, Lacaud G, Kieny MP, Sabatie J, Brown SW, Lecocq JP, Girard M. Isolation of recombinant partial gag gene product p18 (HIV-1Bru) from Escherichia coli. J Chromatogr A 1989; 476:99-112. [PMID: 2674178 DOI: 10.1016/s0021-9673(01)93860-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The membrane-associated structural protein, p18, of the human immunodeficiency virus (HIV-1), has been expressed in Escherichia coli. The recombinant protein was purified by cation-exchange chromatography on S Sepharose followed by cation-exchange high-performance liquid chromatography (HPLC) on Sulfoethyl Aspartamide. The isolation of 28.7 mg of recombinant p18 from 16.71 of cell culture represents an overall yield of ca. 20%. Recombinant p18 was characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis, reversed-phase HPLC, amino acid composition and amino acid sequence analysis of the N-terminus. Edman degradation of peptides generated by trypsin or Staphylococcus aureus V8 proteolytic digestion, including the C-terminus, confirmed the amino acid sequence to be that predicted from the cDNA. A C-terminally cleaved form of recombinant p18, p18LM, was separated in the cation-exchange HPLC step and was partially characterized in parallel with the intact molecule. By Western blotting it was shown that recombinant p18 in addition to the cleaved form p18LM is recognized by a monoclonal antibody which was generated against the natural protein from HIV-1.
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Purification and characterization of human immunodeficiency virus (HIV) core precursor (p55) expressed in Saccharomyces cerevisiae. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)80179-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Padberg C, Nowlan S, Mermer B. Recombinant polypeptides from the human immunodeficiency virus reverse transcriptase define three epitopes recognized by antibodies in sera from patients with acquired immunodeficiency syndrome. AIDS Res Hum Retroviruses 1989; 5:61-71. [PMID: 2470400 DOI: 10.1089/aid.1989.5.61] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Eight fragments derived from the HIV-1 pol gene were expressed as recombinant polypeptides in Escherichia coli. The fragments were from the portion of the pol gene that encodes the reverse transcriptase. The expressed peptides were analyzed immunologically with sera from HIV-1-infected individuals. Three distinct immunogenic epitopes were identified. These determinants are presumably located on the surface of the native reverse transcriptase. Each epitope was included in a fusion protein that was expressed at high levels in bacteria. These proteins may provide reagents of potential diagnostic value.
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Affiliation(s)
- C Padberg
- Department of Molecular Biology, Baxter Healthcare Corporation, Cambridge, MA 02139
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Kurstak E, Marusyk R, Salmi A, Babiuk L, Kurstak C, Van Regenmortel M. Detection of viral antigens and antibodies. Enzyme immunoassays. Subcell Biochem 1989; 15:1-37. [PMID: 2678615 DOI: 10.1007/978-1-4899-1675-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Nair MP, Pottathil R, Heimer EP, Schwartz SA. Immunoregulatory activities of human immunodeficiency virus (HIV) proteins: effect of HIV recombinant and synthetic peptides on immunoglobulin synthesis and proliferative responses by normal lymphocytes. Proc Natl Acad Sci U S A 1988; 85:6498-502. [PMID: 3045818 PMCID: PMC282000 DOI: 10.1073/pnas.85.17.6498] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Recombinant and synthetic peptides corresponding to envelope proteins of the human immunodeficiency virus (HIV) were examined for their effects on the activities of lymphocytes from normal donors in vitro. Although lymphocytes cultured with env-gag peptides produced significant amounts of IgG, addition of env-gag peptides to a pokeweed mitogen-induced B-cell activation system resulted in suppression of immunoglobulin synthesis by normal lymphocytes. Recombinant antigens, env-gag and env-80 dihydrofolate reductase (DHFR), produced a substantial proliferative response by peripheral blood mononuclear cells (PBMC) as determined by [3H]thymidine incorporation. PBMC precultured with HIV synthetic peptide env 578-608 also manifested significant proliferative responses as compared to control cultures. CD3+ lymphocytes precultured with recombinant HIV antigens, env-gag and env-80 DHFR, and synthetic HIV peptide, env 487-511, showed moderate but significant proliferative responses. Both recombinant antigens and synthetic peptides also produced a dose-dependent stimulatory effect on proliferation by CD3- lymphocytes. Stimulation of CD3+ and CD3- lymphocyte subpopulations induced by env-gag peptides was specifically inhibited by goat anti-env-gag polyclonal antibodies, demonstrating the specificity of the reaction. These studies demonstrate that recombinant and synthetic peptides of the HIV genome express immunoregulatory T- and B-cell epitopes. Identification of unique HIV epitopes with immunogenic and immunoregulatory activities is necessary for the development of an effective vaccine against HIV infection.
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Affiliation(s)
- M P Nair
- Department of Pediatrics, University of Michigan, Ann Arbor 48109-2029
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