Faculty active in this area of research are listed below. For a brief description of their research interests, click on their name in the list. Clicking on the name at the beginning of the brief description links to their detailed personal website.

T. Prescott Atkinson, MD, PhD, Department of Pediatrics
Peter D. Burrows, PhD, Department of Microbiology
Randy Q. Cron, MD, PhD, Department of Pediatrics
Harry Schroeder, MD, PhD, Dept of Medicine/Clin Immun & Rheumatology

T. Prescott Atkinson, MD, PhD Research in my laboratory is focused on the role of infection in chronic diseases, especially arthritis and asthma. Ongoing projects in coordination with the UAB Diagnostic Mycoplasma Laboratory are designed to identify mycoplasmas and ureaplasmas in human samples with particular emphasis on the role of those organisms in chronic asthma and extreme prematurity respectively.  Previous studies in my laboratory established that Mycoplasma pneumoniae is able to activate mast cells to produce IL-4 through sialic acid-dependent binding to the high affinity receptor for IgE, a finding with potential implications in the pathogenesis of asthma and potentially a general mechanism in the activation of cells of the immune system by that organism. Work is currently proceeding to determine the current prevalence of macrolide resistance strains of M. pneumoniae in the Birmingham area. I am also actively engaged in the development of rational strategies to determine the molecular basis for unidentified immunodeficiencies in patients in my weekly clinical immunology clinics at Children’s of Alabama. Such patients may represent natural “knockouts” or dominant negative mutations in signaling molecules and provide valuable insights into critical steps in receptor signaling in the human immune system.

Peter D. Burrows, PhD Dr. Burrows' laboratory is interested in the development and function of B lymphocytes. Immunoglobulin gene rearrangements, as well as a number of poorly understood changes in gene expression, take place as cells progress through this differentiation pathway. We have been using both cellular and molecular approaches to characterize precursors of human B lineage cells and to identify novel genes whose expression is developmentally regulated. Defects in the expression of such genes could lead to immunodeficiency, whereas inappropriate expression might predispose a cell to malignant transformation. His lab has also begun to explore the function of the multifaceted cytokine, transforming growth factor-beta, in regulating B cell development and function and have identified a novel Fc receptor gene that appears to be expressed in the cytoplasm of germinal center B lymphocytes.

Randy Q. Cron, MD, PhD  Host transcription factors exploited by HIV-1. HIV-1, the cause of AIDS, has infected over 40 million individuals world-wide. Although vast improvements in therapy have been developed over the last decade, HIV-1 cannot be totally eliminated from the host due to its ability to enter a resting or latent state in NFATbindHIVCD4 T cells. Because HIV-1 relies on host transcription factors to replicate, we are exploring the role of the calcium activated nuclear factor of activated T cells (NFAT) transcription factors in regulating HIV-1 transcription. We and others have shown that the CsA-sensitive NFAT proteins bind to the proximal HIV-1 promoter/long terminal repeat (LTR) in vitro and up-regulate HIV-1 transcription. We have further demonstrated that NFAT proteins bind to the integrated HIV-1 LTR in primary human CD4 T cells in vivo by chromatin immunoprecipitation, and this binding is disrupted by the regulatory T cell transcription factor, FOXP3. In addition, we are attempting to exploit NFAT activation as a means of activating HIV-1 LTR activity in latently infected cells. Recently, we identified a novel binding site for the c-maf transcription factor located adjacent to the proximal NFAT sites in the HIV-1 LTR. Our studies reveal synergistic transcriptional activation and increased infection of HIV-1 by c-maf, NFAT2, and NFΚB p65 in primary human IL-4-producing CD4 T cells. Thus, c-maf will likely be a novel therapeutic target in the treatment of HIV-1.

Genetic defects in lymphocyte cytolysis in macrophage activation syndrome. Macrophage activation syndrome (MAS) is a hyper-inflammatory immune response in children and adults that is often triggered by certain infectious (e.g. EBV), autoimmune (e.g. lupus), autoinflammatory (e.g. Still disease), and oncologic (e.g. T cell leukemia) disorders. MAS results in pro-inflammatory cytokine storm leading to pancytopenia, coagulopathy, central nervous system dysfunction, and multi-organ system failure. MAS is frequently lethal like its cousin disease familial hemophagocytic lymphohistiocytosis (fHLH). fHLH is uniformly fatal if not treated aggressively and typically presents in the first few months of life in infants Picture2with bi-allelic genetic defects in one of the proteins involved in perforin mediated cytolysis by natural killer (NK) cells and CD8 cytotoxic lymphocytes. Recently, mono-allelic (heterozygous) mutations in cytolytic pathway proteins (e.g. perforin, Munc13-4, Rab27a, etc.) have been identified in a substantial percentage of MAS patients presenting beyond infancy. In our MAS patient cohort, we have identified several mutations, including novel mutants, in a variety of cytolytic pathway genes. Using lentiviral transduction of mutant and wild-type genes into NK cells, we demonstrate decreased cytolytic activity by over-expression of the mutant genes, suggesting a partial dominant-negative effect. These studies suggest that there are likely genetic predispositions to develop MAS, and we are currently exploring the novel mutations and their pathophysiological consequences on lymphocyte mediated cytolytic function.

Harry Schroeder, MD, PhD
   Ultimately, it is the identity and specificity of the lymphocyte antigen receptor that determines the nature of the immune response to antigen. The mechanisms that underlie the diversification of the B- and T-cell antigen receptor repertoires appear to generate receptor diversity at random. However, repeated examples of near to absolute identity of receptor sequences between individuals suggest the existence of genetically programmed constraints that may be designed to bias the immune system to produce preferred, and perhaps optimal, repertoires. The implication is that violation of these programs could lead to immune dysfunction, and thus to disease. To test this hypothesis, we are developing mouse models wherein we force expression of altered, polyclonal repertoires that violate normal constraints on antigen receptor sequence or structure. In the first of these mice, where we have forced expression of arginine, histidine and asparagine in the HCDR3 interval of immunoglobulin H chains, we observed somatic selection against antigen binding sites that contained an excess number of these charged amino acids, yet the system ultimately failed to recapture the tyrosine and glycine residues normally encoded by wild-type germline sequence. B-cell development was impeded, immunity to influenza virus was impaired, and expression of IgG anti-DNA antibodies was enhanced. These results support the view that optimal distinction between self and non-self is a product of evolutionary selection.