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1.  Development of Potential Pharmacodynamic and Diagnostic Markers for Anti-IFN-α Monoclonal Antibody Trials in Systemic Lupus Erythematosus 
To identify potential pharmacodynamic biomarkers to guide dose selection in clinical trials using anti-interferon-alpha (IFN-α) monoclonal antibody (mAb) therapy for systemic lupus erythematosus (SLE), we used an Affymetrix human genome array platform and identified 110 IFN-α/β-inducible transcripts significantly upregulated in whole blood (WB) of 41 SLE patients. The overexpression of these genes was confirmed prospectively in 54 additional SLE patients and allowed for the categorization of the SLE patients into groups of high, moderate, and weak overexpressers of IFN-α/β-inducible genes. This approach could potentially allow for an accurate assessment of drug target neutralization in early trials of anti-IFN-α mAb therapy for SLE. Furthermore, ex vivo stimulation of healthy donor peripheral blood mononuclear cells with SLE patient serum and subsequent neutralization with anti-IFN-α mAb or anti-IFN-α receptor mAb showed that anti-IFN-α mAb has comparable effects of neutralizing the overexpression of type I IFN-inducible genes as that of anti-IFNAR mAb. These results suggest that IFN-α, and not other members of type I IFN family in SLE patients, is mainly responsible for the induction of type I IFN-inducible genes in WB of SLE patients. Taken together, these data strengthen the view of IFN-α as a therapeutic target for SLE.
PMCID: PMC2950308  PMID: 20948567
2.  Comparative Immunogenicity in Rhesus Monkeys of DNA Plasmid, Recombinant Vaccinia Virus, and Replication-Defective Adenovirus Vectors Expressing a Human Immunodeficiency Virus Type 1 gag Gene 
Journal of Virology  2003;77(11):6305-6313.
Cellular immune responses, particularly those associated with CD3+ CD8+ cytotoxic T lymphocytes (CTL), play a primary role in controlling viral infection, including persistent infection with human immunodeficiency virus type 1 (HIV-1). Accordingly, recent HIV-1 vaccine research efforts have focused on establishing the optimal means of eliciting such antiviral CTL immune responses. We evaluated several DNA vaccine formulations, a modified vaccinia virus Ankara vector, and a replication-defective adenovirus serotype 5 (Ad5) vector, each expressing the same codon-optimized HIV-1 gag gene for immunogenicity in rhesus monkeys. The DNA vaccines were formulated with and without one of two chemical adjuvants (aluminum phosphate and CRL1005). The Ad5-gag vector was the most effective in eliciting anti-Gag CTL. The vaccine produced both CD4+ and CD8+ T-cell responses, with the latter consistently being the dominant component. To determine the effect of existing antiadenovirus immunity on Ad5-gag-induced immune responses, monkeys were exposed to adenovirus subtype 5 that did not encode antigen prior to immunization with Ad5-gag. The resulting anti-Gag T-cell responses were attenuated but not abolished. Regimens that involved priming with different DNA vaccine formulations followed by boosting with the adenovirus vector were also compared. Of the formulations tested, the DNA-CRL1005 vaccine primed T-cell responses most effectively and provided the best overall immune responses after boosting with Ad5-gag. These results are suggestive of an immunization strategy for humans that are centered on use of the adenovirus vector and in which existing adenovirus immunity may be overcome by combined immunization with adjuvanted DNA and adenovirus vector boosting.
PMCID: PMC154996  PMID: 12743287
3.  Mamu-A∗01 Allele-Mediated Attenuation of Disease Progression in Simian-Human Immunodeficiency Virus Infection 
Journal of Virology  2002;76(24):12845-12854.
Expression of several major histocompatibility complex (MHC) class I alleles is associated with a protective effect against disease progression in both human immunodeficiency virus type 1 and simian immunodeficiency virus infection. To understand the mechanism underlying this effect, we investigated the expression of the MHC class I allele Mamu-A*01 in simian-human immunodeficiency virus (SHIV) infection, one of the major models for evaluation of AIDS vaccine candidates. We found that disease progression was significantly delayed in Mamu-A∗01-positive rhesus monkeys infected with the highly pathogenic SHIV 89.6P. The delay corresponded not only to a noted Mamu-A∗01-restricted dominant cytotoxic T-lymphocyte (CTL) response but also to a lower viral load in lymph nodes (LN) and, importantly, to minimal destruction of LN structure during early infection. In contrast, Mamu-A∗01-negative monkeys exhibited massive destruction of LN structure with accompanying rapid disease progression. These data indicate that MHC class I allele-restricted CTL responses may play an important role in preservation of lymphoid tissue structure, thereby resulting in attenuation of disease progression in immunodeficiency virus infection.
PMCID: PMC136722  PMID: 12438610
4.  Evaluation of Cytotoxic T-Lymphocyte Responses in Human and Nonhuman Primate Subjects Infected with Human Immunodeficiency Virus Type 1 or Simian/Human Immunodeficiency Virus 
Journal of Virology  2001;75(1):73-82.
Cytotoxic T-lymphocyte (CTL) responses have been implicated as playing an important role in control of human immunodeficiency virus (HIV) infection. However, it is technically difficult to demonstrate CTL responses consistently in nonhuman primate and human subjects using traditional cytotoxicity assay methods. In this study, we systematically evaluated culture conditions that may affect the proliferation and expansion of CTL effector cells and presented a sensitive method for detection of cytotoxicity responses with bulk CTL cultures. We confirmed the sensitivity and specificity of this method by demonstration of vigorous CTL responses in a simian-HIV (SHIV)-infected rhesus macaque. The expansion of epitope-specific CTL effector cells was also measured quantitatively by CTL epitope-major histocompatibility complex tetramer complex staining. In addition, two new T-cell determinants in the SIV gag region are identified. Last, we showed the utility of this method for studying CTL responses in chimpanzee and human subjects.
PMCID: PMC113899  PMID: 11119575
5.  Putative Immunodominant Human Immunodeficiency Virus-Specific CD8+ T-Cell Responses Cannot Be Predicted by Major Histocompatibility Complex Class I Haplotype 
Journal of Virology  2000;74(19):9144-9151.
Recent studies of human immunodeficiency virus (HIV)-specific CD8+ T cells have focused on responses to single, usually HLA-A2-restricted epitopes as surrogate measures of the overall response to HIV. However, the assumption that a response to one epitope is representative of the total response is unconfirmed. Here we assess epitope immunodominance and HIV-specific CD8+ T-cell response complexity using cytokine flow cytometry to examine CD8+ T-cell responses in 11 HLA-A2+ HIV+ individuals. Initial studies demonstrated that only 4 of 11 patients recognized the putative immunodominant HLA-A2-restricted p17 epitope SLYNTVATL, suggesting that the remaining subjects might lack significant HIV-specific CD8+ T-cell responses. However, five of six SLYNTVATL nonresponders recognized other HIV epitopes, and two of four SLYNTVATL responders had greater responses to HIV peptides restricted by other class I alleles. In several individuals, no HLA-A2-restricted epitopes were recognized, but CD8+ T-cell responses were detected to epitopes restricted by other HLA class I alleles. These data indicate that an individual's overall CD8+ T-cell response to HIV is not adequately represented by the response to a single epitope and that individual major histocompatibility complex class I alleles do not predict an immunodominant response restricted by that allele. Accurate quantification of total HIV-specific CD8+ T-cell responses will require assessment of the response to all possible epitopes.
PMCID: PMC102113  PMID: 10982361

Results 1-5 (5)