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W Gregory Alvord

Publications and source records attributed to W Gregory Alvord.

At least 19 recordsLinked to original sources
PubMed2004

Mutations at position 184 of human immunodeficiency virus type-1 reverse transcriptase affect virus titer and viral DNA synthesis.

Methionine at position 184 of human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT) was changed to valine, isoleucine, threonine, or alanine in an HIV-1-based vector. The vectors were analyzed for replication capacity and for resistance to the nucleoside analog 2',3'-dideoxy-3'thiacytidine (3TC) using a single-cycle assay. Viruses containing the valine or isoleucine mutations were highly resistant to 3TC and replicated almost as well as the wild-type virus. The virus containing the threonine mutation was resistant to 3TC, but replicated about 30% as well as the wild-type. The alanine mutation conferred partial resistance to 3TC, but replicated poorly. The amounts of viral DNA synthesized decreased in 3TC-treated cells when the cells were infected with wild-type virus and the M184A mutant. The effect of these mutations on the generation of the ends of the linear viral DNA was determined using the sequence of the 2-LTR circle junctions. The M184T mutation increased the proportion of 2-LTR circle junctions containing a tRNA insertion, suggesting that the mutation affected the RNase H activity of RT.

Binding Sites↗
PubMed2004

gp100(209-2M) peptide immunization of human lymphocyte antigen-A2+ stage I-III melanoma patients induces significant increase in antigen-specific effector and long-term memory CD8+ T cells.

Thirty-five HLA-A2(+) patients with completely resected stage I-III melanoma were vaccinated multiple times over 6 months with a modified melanoma peptide, gp100(209-2M), emulsified in Montanide adjuvant. Direct ex vivo gp100(209-2M) tetramer analysis of pre- and postvaccine peripheral blood mononuclear cells (PBMCs) demonstrated significant increases in the frequency of tetramer(+) CD8(+) T cells after immunization for 33 of 35 evaluable patients (median, 0.36%; range, 0.05-8.9%). Ex vivo IFN-gamma cytokine flow cytometry analysis of postvaccine PBMCs after brief gp100(209-2M) in vitro activation showed that for all of the patients studied tetramer(+) CD8(+) T cells produced IFN-gamma; however, some patients had significant numbers of tetramer(+) IFN-gamma(-) CD8(+)T cells suggesting functional anergy. Additionally, 8 day gp100(209-2M) in vitro stimulation (IVS) of pre- and postvaccine PBMCs resulted in significant expansion of tetramer(+) CD8(+) T cells from postvaccine cells for 34 patients, and these IVS tetramer(+) CD8(+) T cells were functionally responsive by IFN-gamma cytokine flow cytometry analysis after restimulation with either native or modified gp100 peptide. However, correlated functional and phenotype analysis of IVS-expanded postvaccine CD8(+) T cells demonstrated the proliferation of functionally anergic gp100(209-2M)- tetramer(+) CD8(+) T cells in several patients and also indicated interpatient variability of gp100(209-2M) stimulated T-cell proliferation. Flow cytometry analysis of cryopreserved postvaccine PBMCs from representative patients showed that the majority of tetramer(+) CD8+ T cells (78.1 +/- 4.2%) had either an "effector" (CD45 RA(+)/CCR7(-)) or an "effector-memory" phenotype (CD45RA(-)/CCR7(-)). Notably, analysis of PBMCs collected 12-24 months after vaccine therapy demonstrated the durable presence of gp100(209-2M)-specific memory CD8(+) T cells with high proliferation potential. Overall, this report demonstrates that after vaccination with a MHC class I-restricted melanoma peptide, resected nonmetastatic melanoma patients can mount a significant antigen-specific CD8(+) T-cell immune response with a functionally intact memory component. The data further support the combined use of tetramer binding and functional assays in correlated ex vivo and IVS settings as a standard for immunomonitoring of cancer vaccine patients.

Antigens, Neoplasm↗
PubMed2004

Evaluation of the safety, immunogenicity, and protective efficacy of whole inactivated simian immunodeficiency virus (SIV) vaccines with conformationally and functionally intact envelope glycoproteins.

A novel, general approach to chemical inactivation of retroviruses was used to produce inactivated simian immunodeficiency virus (SIV) particles with functional envelope glycoproteins. Inactivated virions of three different virus isolates (SIVmne E11S, SIVmac239, and SIVmac239 g4,5), prepared by treatment with 2,2'-dithiodipyridine (aldrithol-2, AT-2), were not detectably infectious, in vitro or in vivo. Immunization of pigtailed macaques with inactivated SIVmne E11S particles, without adjuvant, induced both humoral and cellular immune responses. Four of six animals immunized with the inactivated particles did not show measurable SIV RNA in plasma (<100 copy Eq/ml) following intravenous challenge with pathogenic, homologous virus (SIVmne E11S), compared to peak values of > or =10(6) copy Eq/ml in challenged SIV-naive control animals (p = 0.0001). Despite the absence of measurable viral RNA in plasma in these animals, culturable virus and viral DNA were initially detectable in blood and lymph node specimens; in contrast to control animals, SIV DNA could no longer be detected in PBMC by 10 weeks postchallenge in five of six SIV-immunized animals (p = 0.0001). However, vaccines did not resist a sequential rechallenge with the heterologous pathogenic virus SIVsm E660. AT-2-inactivated virus with functional envelope glycoproteins is a novel class of vaccine immunogen and was noninfectious, under conditions of rigorous in vivo challenge, and induced both binding and neutralizing antibody responses, along with cellular immune responses. Results suggest that immunization facilitated effective containment of pathogenic homologous challenge virus. With further optimization, AT-2-inactivated viral particles may be a useful class of immunogen in the development of a vaccine to prevent AIDS.

Animals↗
PubMed2003

Receptor glycosylation regulates Ly-49 binding to MHC class I.

Murine NK cells express the Ly-49 family of class I MHC-binding receptors that control their ability to lyse tumor or virally infected host target cells. X-ray crystallography studies have identified two predominant contact sites (sites 1 and 2) that are involved in the binding of the inhibitory receptor, Ly-49A, to H-2D(d). Ly-49G2 (inhibitory) and Ly-49D (activating) are highly homologous to Ly-49A and also recognize H-2D(d). However, the binding of Ly-49D and G(2) to H-2D(d) is of lower affinity than Ly-49A. All Ly-49s contain N-glycosylation motifs; however, the importance of receptor glycosylation in Ly-49-class I interactions has not been determined. Ly-49D and G(2) contain a glycosylation motif (NTT (221-223)), absent in Ly-49A, adjacent to one of the proposed binding sites for H-2D(d) (site 2). The presence of a complex carbohydrate group at this critical site could interfere with class I binding. In this study, we are able to demonstrate for the first time that Ly-49D binds H-2D(d) in the presence of mouse beta(2)-microglobulin. We also demonstrate that glycosylation of the NTT (221-23) motif of Ly-49D inteferes with recognition of H-2D(d). Alteration of the Ly-49D-NTT (221-23) motif to abolish glycosylation at this site resulted in enhanced H-2D(d) binding and receptor activation. Furthermore, glycosylation of Ly-49G2 at NTT (221-23) also reduces receptor binding to H-2D(d) tetramers. Therefore, the addition of complex carbohydrates to the Ly-49 family of receptors may represent a mechanism by which NK cells regulate affinity for host class I ligands.

Amino Acid Motifs↗
PubMed2003

Gene expression dose-response changes in microarrays after exposure of human peripheral lung epithelial cells to nickel(II).

Occupational exposure to nickel compounds is associated with lung cancer risk; both genotoxic and epigenetic mechanisms have been proposed. For comprehensive examination of the acute effects of nickel(II) acetate on gene expression in cultured human peripheral lung epithelial HPL1D cells, microarray analyses were carried out with cDNA chips (approximately 8000 cDNAs). Cells were exposed for 24 h to nontoxic (50, 100, and 200 microM) or toxic (400, 800, and 1600 microM) nickel(II) concentrations. Cluster analysis was applied to the 868 genes with > or = 2-fold change at any concentration. Two main clusters showed marked up- or down-regulation at the highest, toxic concentrations. The data further subdivided into 10 highly cohesive clusters with high probability, and of these only 2 had the same response trend at low nontoxic as at high concentrations, an observation of clear relevance to the process of high- to low-dose extrapolation in risk assessment. There were 113 genes showing > or = 2-fold change at the three lower nontoxic concentrations, those most relevant to in vivo carcinogenesis. In addition to expected responses of metallothionein, ferritin, and heat-shock proteins, the results revealed for the first time changed expression of some potential cancer-related genes in response to low-dose Ni(II): RhoA, dyskerin, interferon regulatory factor 1, RAD21 homologue, and tumor protein, translationally controlled. Overall, most of the genes impacted by nontoxic concentrations of nickel(II) acetate related to gene transcription, protein synthesis and stability, cytoskeleton, signaling, metabolism, cell membrane, and extracellular matrix.

Algorithms↗
PubMed2003

Vaccination of women with metastatic breast cancer, using a costimulatory gene (CD80)-modified, HLA-A2-matched, allogeneic, breast cancer cell line: clinical and immunological results.

MDA-MB-231, an HLA-A2(+), HER2/neu(+) allogeneic breast cancer cell line genetically modified to express the costimulatory molecule CD80 (B7-1), was used to vaccinate 30 women with previously treated stage IV breast cancer. Expression of CD80 conferred the ability to deliver a costimulatory signal and thereby improved the antigen presentation capability of the tumor cells to patient T cells in vitro. Patients were vaccinated with 10(7) or 10(8) irradiated gene-modified tumor cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) or BCG, three times at 2-week intervals and then monthly until progressive disease developed. GM-CSF-related flulike symptoms and minor injection site reactions were observed frequently. Prolonged disease stabilization was observed in four patients but no objective tumor regressions were seen. Immune responses were measured in matched peripheral blood samples collected before and after treatment from 9 of 15 patients treated at the 10(8) tumor cell dose. Four patients exhibited MHC class I-restricted cytokine production in response to the parental breast cancer cell line. One patient maintained an increased number of circulating tumor-specific, interferon gamma-secreting CD8(+) T cells for 24 months after the last vaccination. One patient exhibited a tumor-specific interleukin 5 response to an autologous tumor cell line. This immunization strategy proved to be safe and feasible, and induced tumor-specific immune responses in a minority of patients; however, no objective tumor regressions were observed.

Adult↗
PubMed2003

Adjuvant immunization of HLA-A2-positive melanoma patients with a modified gp100 peptide induces peptide-specific CD8+ T-cell responses.

PURPOSE: To measure the CD8+ T-cell response to a melanoma peptide vaccine and to compare an every-2-weeks with an every-3-weeks vaccination schedule. PATIENTS AND METHODS: Thirty HLA-A2-positive patients with resected stage I to III melanoma were randomly assigned to receive vaccinations every 2 weeks (13 vaccines) or every 3 weeks (nine vaccines) for 6 months. The synthetic, modified gp100 peptide, g209-2M, and a control peptide, HPV16 E7, were mixed in incomplete Freund's adjuvant and injected subcutaneously. Peripheral blood mononuclear cells obtained before and after vaccination by leukapheresis were analyzed using a fluorescence-based HLA/peptide-tetramer binding assay and cytokine flow cytometry. RESULTS: Vaccination induced an increase in peptide-specific T cells in 28 of 29 patients. The median frequency of CD8+ T cells specific for the g209-2M peptide increased markedly from 0.02% before to 0.34% after vaccination (P <.0001). Eight patients (28%) exhibited peptide-specific CD8+ T-cell frequencies greater than 1%, including two patients with frequencies of 4.96% and 8.86%, respectively. Interferon alfa-2b-treated patients also had significant increases in tetramer-binding cells (P <.0001). No difference was observed between the every-2-weeks and the every-3-weeks vaccination schedules (P =.59). CONCLUSION: Flow cytometric analysis of HLA/peptide-tetramer binding cells was a reliable means of quantifying the CD8+ T-cell response to peptide immunization. This assay may be suitable for use in future trials to optimize different vaccination strategies. Concurrent interferon treatment did not inhibit the development of a peptide-specific immune response and vaccination every 2 weeks, and every 3 weeks produced similar results.

Adult↗
PubMed2003

A replication competent adenovirus 5 host range mutant-simian immunodeficiency virus (SIV) recombinant priming/subunit protein boosting vaccine regimen induces broad, persistent SIV-specific cellular immunity to dominant and subdominant epitopes in Mamu-A*01 rhesus macaques.

CTL are important in controlling HIV and SIV infection. To quantify cellular immune responses induced by immunization, CD8(+) T cells specific for the subdominant Env p15m and p54m epitopes and/or the dominant Gag p11C epitope were evaluated by tetramer staining in nine macaques immunized with an adenovirus (Ad) 5 host range mutant (Ad5hr)-SIVenv/rev recombinant and in four of nine which also received an Ad5hr-SIVgag recombinant. Two Ad5hr-SIV recombinant priming immunizations were followed by two boosts with gp120 protein or an envelope polypeptide representing the CD4 binding domain. Two mock-immunized macaques served as controls. IFN-gamma-secreting cells were also assessed by ELISPOT assay using p11C, p15m, and p54m peptide stimuli and overlapping pooled Gag and Env peptides. As shown by tetramer staining, Ad-recombinant priming elicited a high frequency of persistent CD8(+) T cells able to recognize p11C, p15m, and p54m epitopes. The presence of memory cells 38 wk postinitial immunization was confirmed by expansion of tetramer-positive CD8(+) T cells following in vitro stimulation. The SIV-specific CD8(+) T cells elicited were functional and secreted IFN-gamma in response to SIV peptide stimuli. Although the level and frequency of response of peripheral blood CD8(+) T cells to the subdominant Env epitopes were not as great as those to the dominant p11C epitope, elevated responses were observed when lymph node CD8(+) T cells were evaluated. Our data confirm the potency and persistence of functional cellular immune responses elicited by replication competent Ad-recombinant priming. The cellular immunity elicited is broad and extends to subdominant epitopes.

Adenoviruses, Human↗
PubMed2003

TNF plays an essential role in tumor regression after adoptive transfer of perforin/IFN-gamma double knockout effector T cells.

We have recently shown that effector T cells (T(E)) lacking either perforin or IFN-gamma are highly effective mediators of tumor regression. To rule out compensation by either mechanism, T(E) deficient in both perforin and IFN-gamma (perforin knockout (PKO)/IFN-gamma knockout (GKO)) were generated. The adoptive transfer of PKO/GKO T(E) mediated complete tumor regression and cured wild-type animals with established pulmonary metastases of the B16BL6-D5 (D5) melanoma cell line. PKO/GKO T(E) also mediated tumor regression in D5 tumor-bearing PKO, GKO, or PKO/GKO recipients, although in PKO/GKO recipients efficacy was reduced. PKO/GKO T(E) exhibited tumor-specific TNF-alpha production and cytotoxicity in a 24-h assay, which was blocked by the soluble TNFRII-human IgG fusion protein (TNFRII:Fc). Blocking TNF in vivo by administering soluble TNFR II fusion protein (TNFRII:Fc) significantly reduced the therapeutic efficacy of PKO/GKO, but not wild-type T(E). This study identifies perforin, IFN-gamma, and TNF as a critical triad of effector molecules that characterize therapeutic antitumor T cells. These insights could be used to monitor and potentially tune the immune response to cancer vaccines.

Adoptive Transfer↗
PubMed2003

Mutation of amino acids in the connection domain of human immunodeficiency virus type 1 reverse transcriptase that contact the template-primer affects RNase H activity.

The crystal structure of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase in a complex with an RNA-DNA template-primer identified amino acids in the connection domain that make specific contacts with the nucleic acid. We analyzed the effects of mutations in these amino acids by using a one-round HIV-1 vector. Mutations in amino acids in the connection domain generally had small effects on virus titers. To determine whether the mutations affected the level of RNase H activity or the specificity of RNase H cleavage, we used the two-long-terminal-repeat circle junction as a surrogate for the ends of linear viral DNA; specific RNase H cleavages determine the ends of the viral DNA. Several of the mutations in the connection domain affected the frequency of the generation of viral DNAs with aberrant ends. The mutation H361A had the largest effect on the titer and on the generation of DNAs with aberrant ends. H361 contacts the phosphate backbone of the nucleic acid in the same location as amino acid Y501 in the RNase H primer grip. Mutations at Y501 have been shown to decrease the virus titer and affect the specificity of RNase H cleavage. H361A affected the frequency of the generation of linear viral DNAs with aberrant ends, but in general the connection domain mutations had subtle effects on the efficiency of RNase H cleavage. The results of this study suggest that, in addition to its primary role in linking the polymerase and RNase H domains, the connection subdomain has a modest role in binding and positioning the nucleic acid.

Amino Acid Sequence↗
PubMed2003

Mutations in the 5' end of the human immunodeficiency virus type 1 polypurine tract affect RNase H cleavage specificity and virus titer.

The RNase H activity of retroviral reverse transcriptases (RTs) degrades viral genomic RNA after it has been copied into DNA, removes the tRNA used to initiate negative-strand DNA synthesis, and generates and removes the polypurine tract (PPT) primer used to initiate positive-strand DNA synthesis. The cleavages that remove the tRNA and that generate and remove the PPT primer must be specific to generate linear viral DNAs with ends that are appropriate for integration into the host cell genome. The crystal structure of human immunodeficiency virus type 1 (HIV-1) RT in a complex with an RNA/DNA duplex derived from the PPT revealed that the 5' end of the PPT deviates from traditional Watson-Crick base pairing. This unusual structure may play a role in the proper recognition of the PPT by HIV-1 RT. We made substitution mutations in the 5' end of the PPT and determined their effects on virus titer. The results indicated that single and double mutations in the 5' end of the PPT had modest effects on virus replication in a single-cycle assay. More complex mutations had stronger effects on virus titer. Analysis of the two-long-terminal-repeat circle junctions derived from infecting cells with the mutant viruses indicated that the mutations affected RNase H activity, resulting in the retention of PPT sequences on viral DNA. The mutants tested preferentially retained specific segments of the PPT, suggesting an effect on cleavage specificity. These results suggest that structural features of the PPT are important for its recognition and cleavage in vivo.

Base Sequence↗
PubMed2003

Exercise and intestinal polyp development in APCMin mice.

PURPOSE: Epidemiological evidence suggests that physical activity protects against colon cancer. We previously used a mouse predisposed to intestinal polyps (APCMin) to evaluate this association and found the suggestion of fewer polyps in exercised males but not females. The present study was designed to further explore the potential exercise x sex interaction on polyp development and to begin to look at potential mechanisms. METHODS: Six-week-old APCMin mice (N = 60 males; 60 females) were randomly assigned to one of two groups by sex: treadmill running at 20 m.min-1, 5% grade, 45 min.d-1, 5 d.wk-1 (EX) or nonrunning controls (CON) (N = 30 per group). EX mice ran in running wheels while in quarantine (weeks 0-3), followed by treadmill running weeks 3-8. Body weights were measured weekly. Urine was collected at 5 wk and fasting blood at 7.5 wk. Body composition was measured, serum was frozen, and polyp number and size were measured at sacrifice. RESULTS: EX resulted in lower body weights (P < 0.01) and reduced fat mass (P < 0.01). Fasting glucose was lower in EX (P < 0.01), and leptin was lower in EX (P = 0.05) compared with CON. EX did not affect serum insulin-like growth factor-1 or urinary corticosterone. Total polyp number and size were not statistically different between groups; however, there were fewer jejunal polyps in EX (3.6 +/- 0.7, mean +/- SE) versus CON males (5.2 +/- 0.8; P = 0.04) and an even larger difference when only the consistent runners were kept in the analysis (2.7 +/- 0.5 in EX; P = 0.01). CONCLUSION: Despite favorable changes in body composition, blood glucose, and leptin, 8 wk of running resulted in only minor changes related to polyp development in male but not female APCMin mice.

Animals↗
PubMed2003

Gestation stage-specific oxidative deoxyribonucleic acid damage from sidestream smoke in pregnant rats and their fetuses.

Transplacental exposure to environmental tobacco smoke (ETS) is a possible cancer risk factor in offspring. The authors exposed pregnant Sprague-Dawley rats to a relevant dose of ETS (1 mg/m3) from gestation day 4 to days 16 or 21. They then assayed tissues for levels of 8-oxo-2'-deoxyguanosine (8-oxo-dG), a marker of oxidative deoxyribonucleic acid damage. ETS exposure ending on gestation day 16 resulted in statistically significant increases in 8-oxo-dG in maternal liver and kidney and in fetal kidney. On gestation day 21, there were significant 8-oxo-dG increases in fetal liver and brain. These gestational stage- and tissue-specific increases of 1.2- to 1.4-fold are similar to the putative relative increases in risk of human cancers related to ETS.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2002

Gadd45a protects against UV irradiation-induced skin tumors, and promotes apoptosis and stress signaling via MAPK and p53.

Skin cancer is the most frequent form of malignancy in the world, and UV radiation is the primary environmental carcinogen responsible for its development. Herein we demonstrate that Gadd45a is a critical factor protecting the epidermis against UV radiation-induced tumorigenesis by promoting damaged keratinocytes to undergo apoptosis and/or cell cycle arrest, two crucial events that prevent the expansion of mutant or deregulated cells. Whereas Gadd45a has been implicated in cell cycle arrest, apoptosis, and DNA repair, to determine the physiological function of endogenous Gadd45a after genotoxic stress, the skin of Gadd45a-null mice was targeted with UV radiation. We report that Gadd45a induces apoptosis and cell cycle arrest by maintaining p38 and c-JNK MAPK activation in keratinocytes. The absence of Gadd45a results in loss of sustained p38/JNK MAPK activity beyond 15-30 min after UV radiation that leads to inadequate p53 activation and loss of normal activation of G(1) and G(2) checkpoints. Moreover, loss of Gadd45a dramatically reduces UV-induced apoptotic keratinocytes, "sunburn cells." Consequently, Gadd45a-null mice are more prone to tumors relative to wild-type mice. Therefore, we conclude that Gadd45a, like p53, is a key component protecting skin against UV-induced tumors.

Animals↗
PubMed2002

Synergistic engagement of an ineffective endogenous anti-tumor immune response and induction of IFN-gamma and Fas-ligand-dependent tumor eradication by combined administration of IL-18 and IL-2.

IFN-gamma is a critical component of the endogenous and many cytokine-induced antitumor immune responses. In this study we have shown that the combination of IL-18 and IL-2 (IL-18/IL-2) synergistically enhances IFN-gamma production both in vitro and in vivo, and synergizes in vivo to induce complete durable regression of well-established 3LL tumors in >80% of treated mice. We have observed a nascent, but ineffective, host immune response against 3LL that depends on endogenous IFN-gamma and IL-12 production and the Fas/Fas ligand (Fas-L) pathway. The combined administration of IL-18/IL-2 engages this endogenous response to induce tumor regression via a mechanism that is independent of NK and NKT cells or IL-12, but is critically dependent on CD8(+) T cells, IFN-gamma, and the Fas/Fas-L pathway. These studies demonstrate the importance of IFN-gamma as well as the Fas/Fas-L pathway in both endogenous and cytokine-driven antitumor immune responses engaged by IL-18/IL-2 and provide preclinical impetus for clinical investigation of this potent anti-tumor combination.

Adjuvants, Immunologic↗
PubMed2002

Comparative analysis of HIV-1 viral load assays on subtype quantification: Bayer Versant HIV-1 RNA 3.0 versus Roche Amplicor HIV-1 Monitor version 1.5.

Quantification of HIV-1 subtypes is essential for appropriate clinical management. Whereas viral load assays were initially developed to accurately quantify subtype B, the recent worldwide spread of non-B subtypes and the introduction of treatment programs in regions with non-B subtypes have prompted adaptations of these assays. The Bayer Versant HIV-1 RNA 3.0 Assay (branched DNA [bDNA] 3.0) and the Roche Amplicor HIV-1 Monitor version 1.5 (Amplicor 1.5) assays are reported to quantify all subtypes in group M; however, evaluation of performance characteristics remains limited. In this study, we evaluated the accuracy and reliability of bDNA 3.0 and Amplicor 1.5 on multiple serially diluted viral isolates from HIV-1 group M, subtypes A through F. Testing was conducted on both assay systems in two independent laboratories. Comparative pansubtype quantification from regression analysis showed that quantification by bDNA 3.0 was approximately 0.3 log-fold lower than that by Amplicor 1.5. Comparative pansubtype accuracy analysis showed data points more closely distributed about their respective regression lines and thus showing greater reliability by bDNA 3.0 than by Amplicor 1.5.

Branched DNA Signal Amplification Assay↗
PubMed2002

Insertion of HIV-1 genes into Ad4DeltaE3 vector abrogates increased pathogenesis in cotton rats due to E3 deletion.

Adenovirus type 5 (Ad5) E3 region proteins abrogate Ad pathogenicity in the lungs of cotton rats. Our use of Ad4-HIV E3-deleted (DeltaE3) recombinants as vaccines necessitates further examination of these viruses for enhanced pathogenesis. Equivalent infectious doses of Ad4 wild-type (Ad4WT), Ad4DeltaE3, and two recombinants: Ad4DeltaE3HIVenv and Ad4DeltaE3HIVgag, were inoculated intranasally into cotton rats. Ad4 viruses did not replicate in the lungs, but caused mild pathologic effects, including peribronchiolitis, bronchitis, alveolitis, and interstitial pneumonia. As found previously for Ad5, deletion of Ad4 E3 genes resulted in increased lung pathology. Surprisingly, insertion of HIV genes into this region significantly restored protection attributed to E3 gene products, diminishing overall pathologic effects to Ad4WT levels (P < 0.0001). Similarly, following administration of equivalent particle numbers of the four viruses, only Ad4DeltaE3 caused increased overall pathology, while the two HIV recombinant viruses showed effects comparable to Ad4WT (P < 0.01). Our observation that Ad4DeltaE3HIV recombinants are as safe in cotton rats as Ad4WT encourages their continued development as AIDS vaccines.

AIDS Vaccines↗