Nafees Ahmad
Professor, BIO5 Institute
Professor, Immunobiology
Primary Department
Department Affiliations
(520) 626-7022
Research Interest
Nafees Ahmad, Ph.D., Professor of ImmunobiologyResearch Interests:1. Molecular mechanisms of HIV-1 vertical transmission2. Molecular mechanisms of HIV-1 pathogenesis in infants and children 3. Molecular mechanisms of HIV-1 infection in immature and mature mononuclear cells4. Identification and characterization of cellular factors involved in HIV-1 replication in immature and mature mononuclear cells5. Biological activity of anti-HIV compoundsThe main focus of my laboratory is understanding the molecular mechanisms of human immunodeficiency virus type 1 (HIV-1) mother-to-infant transmission and pathogenesis of pediatric AIDS (HIV-1 infection in children). Areas of investigation include: Molecular and biological characterization of HIV-1 isolates involved in maternal-fetal transmission; Genetic variability of HIV-1 following mother-to-infant transmission; Viral determinants, including viral heterogeneity, functional conservation/divergence of various HIV-1 genes, presence/absence of motifs in HIV-1 genes, replication efficiency, cell tropism, and cytopathic effects associated with HIV-1 maternal-fetal transmission; Viral and host factors associated with HIV-1 evolution, replication, pathogenesis and disease progression in infected infants and children; Molecular mechanisms of HIV-1 infection in immature and mature mononuclear cells; Kinetics of HIV-1 replication in immature hosts (infants) primary lymphocytes and monocytes/macrophages; Mechanisms of HIV-1 infection in immature and mature mononuclear cells, including entry and post-entry events, HIV-1 gene expression and T-cell development, Biological activity of anti-HIV compounds in tissue culture system of T-cell lines, primary lymphocytes and monocytes/macrophages and receptor/coreceptor cell lines, Characterization of cellular factors in immature and mature mononuclear cells that may influence HIV replication differentially.

Publications

Ahmad, N. (2017). Characterization of HIV quasispecies in virologically controlled HIV-infected older patients receiving antiretroviral therapy. Journal of Virology.
Ahmad, N. (2017). Recovery of HIV-mediated Immune Aging of T Cells in Virologically Controlled HIV-Infected Aging Patients on Antiretroviral Therapy. Proceedings of National Academy of Sciences.
Bashyal, B. P., Wellensiek, B. P., Ramakrishnan, R., Faeth, S. H., Ahmad, N., & Gunatilaka, A. A. (2014). Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi. Bioorganic & medicinal chemistry, 22(21), 6112-6.
BIO5 Collaborators
Nafees Ahmad, Leslie Gunatilaka

Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, altertoxins V (1) and VI (2) together with the known compounds, altertoxins I (3), II (4), and III (5). The structures of 1 and 2 were determined by detailed spectroscopic analysis and those of 3-5 were established by comparison with reported data. When tested in our cell-based assay at concentrations insignificantly toxic to T-cells, altertoxins V (1), I (3), II (4), and III (5) completely inhibited replication of the HIV-1 virus at concentrations of 0.50, 2.20, 0.30, and 1.50 μM, respectively. Our findings suggest that the epoxyperylene structural scaffold in altertoxins may be manipulated to produce potent anti-HIV therapeutics.

Ahmad, N. (2017). HIV infection and bone abnormalities. The Open Orthopaedics Journal, 11, 777-784.
Badowski, M., Shultz, C. L., Eason, Y., Ahmad, N., & Harris, D. T. (2014). The influence of intrinsic and extrinsic factors on immune system aging. Immunobiology, 219(6), 482-5.

Sex and age-matched wild-type and TCR transgenic mice were infected with cytomegalovirus (CMV) at 6 months of age and followed for 12 additional months to examine aging of the immune system. It was found that viral infection of C57Bl/6 mice resulted in accelerated aging of the immune system as shown by a loss of CD8(+)28(+) cells and an accumulation of KLRG1(+) T cells. CMV infection of OT-1 transgenic mice had no influence on immune aging of these mice which nonetheless demonstrated an accumulation of CD8(+)28(-) and KLRG1(+) T cells with time. CD4(+) T cells were unaffected in either strain of mice. Thus, immunological aging was found to be due to both cell-intrinsic and cell-extrinsic factors. Persistent viral infections may accelerate immunological aging but consideration must be given to individual variation in the aging process.