The lab is currently involved in two main projects. The first is to study how the final 29 amino acids of Tat affect Tat in HIV pathogenesis. The long term goal of this work is to elucidate the mechanism by which HIV causes nerve cell death and dementia. Not all HIV patients develop neurological manifestations , and HIV does not appear to be able to infect neurons —thus , HIV -associated dementia remains an enigma.
The second project involves a comparison of Tat, Nef, and viral promoter (LTR) sequences between two groups of pediatric HIV patients —one group with HIV only and the other with HIV and AIDS. This is a pilot project to identify the viral differences that correspond to differences in response to therapy and clinical outcome. This project is also particularly important because it addresses health disparities in HIV-infected children.
PROJECTS
Project 1
Project Number:
SO6GM08239-17
Source:
NIH/NIGMS/MBRS SCORE
Dates of award:
06/01/02-05/31/05
HIV-1-associated dementia (HAD), correlates poorly with viral load itself, but shows a strong relationship to certain HIV-1 proteins. The Tat protein of HIV-1, which occurs in three forms (Tat72 (first 72 amino acids), Tat 86 and Tat101), is a known regulator of cytokines and as such has been implicated in the onset and development of HAD. The objective of this project is to demonstrate and quantify regulatory differences among these three forms of this important protein. In order to accomplish this aim, the various forms of Tat are produced and purified from cultures of E. coli and then applied to our model cell line U87MG (astrocytoma cells). We then observe the changes in both message and protein levels of IL-8, MCP-1 and TNF-alpha. Our model predicts that Tat101 provides added function as compared to the one-exon Tat72, and that the mechanism of action may be a difference at the level of transcriptional regulation as opposed to message stability or translation.
Staff on project:
Gladys B.Chompré
Laboratory Supervisor
Project 2
Viral Sequences in Pediatric HIV infection in PR
Project Number:
G12RR003050
Source:
NIH/NCRR/RCMI
Dates of award:
10/01/03-06/30/08
Pediatric HIV infection represents a health disparity. Prenatal and postnatal treatment have been remarkably effective in lowering the risk of vertical transmission in developed countries. Yet this mode of transmission remains an important health issue in many developing countries and among minority populations with limited access to high quality health care. The relative lack of studies examining HIV/AIDS in children exacerbates this problem. Among vertically infected children, some progress rapidly (within four years) to AIDS, while others maintain control of the infection and do not develop AIDS for more than eight years. Many factors may account for this different clinical presentation, including a genetic variation in the virus. In adult infection, deficiencies in viral nef and LTR sequences have been linked to several cases of long-term nonprogression. We will use an innovative and complementary approach of studying the viral sequences that account for rapid infection (as compared to the normal or slower rate ) , to identify the viral elements responsible for the development of AIDS in pediatric patients. We have four target sequences: tat exon 1, tat exon 2, nef, and LTR. These sequences will be compared in two groups of Puerto Rican HIV-1-infected children (Group 1 = HIV/AIDS; Group 2 = HIV/no AIDS). The same sequences will be compared longitudinally (for thirty months at six-month intervals) in each of this pilot study’s participant s. Our hypothesis is that viral gene expression levels (determined by LTR and Tat) and viral sequences of Nef and Tat will comprise important determinants of disease progression rate in HIV infection. Th e successful completion of the specific aims of this pilot proposal will address our mid-term goal to generate data for publication ; in addition , the data will be used in the design of a study involving a larger population of HIV-1 infected children in order to more firmly establish the roles of these viral components in disease progression. This work will address the long-range goal of advancing our understanding of the mechanisms employed by the virus to propagate infection and cause disease. It is expected that such information will prove to be of clinical benefit as a prognostic factor in pediatric HIV infection. Further, it may result in the development of therapeutic alternatives to the current antiretroviral drugs. This is particularly important as resistance to antiretrovirals develops with time, and also in light of the fact that, in the developing world, there is a lack of physical facilities and economic support for these expensive interventions .
Ziomara Marrero
Laboratory Technician
Our Team
Left to Right: Ziomara Marrero, Agnes Constantino, Julyann Pérez, Marta González, Gladys Chompré & Mariam González.
ABOUT OUR LAB
Biosafety cabinet & incubator
MJ Research Dyad thermal cycler
Typhoon 9200
Our laboratory is located in the Northeast corner of the second floor of the Research Building at the Ponce School of Medicine. The major equipment for these projects consists of tissue culture facilities (biosafety cabinet and incubator), as well as an MJ Research Dyad thermal cycler and a Molecular Dynamics/General Electric Typhoon 9200 (located our adjoining labs). The major funding for this equipment was from NIH-NIGMS-MBRS ( SO6GM08239) with an additional significant contribution from NIH-NCRR-RCMI (G12 RR003050). Additional essential equipment —specifically the Visible Genetics OpenGene Automated sequencing systems— is accessed through the AIDS Research Program Core facility, also funded by NIH-NCRR-RCMI (G12 RR003050).
