1. Bolaños, Benjamin, Ph.D. (Associate Professor)
   e-mail:bbolanos@rcm.upr.edu
   
   Four major research areas are actively pursued in my laboratory:

1. Purification and characterization of an immunosuppressive component from Cryptococcus neoformans. In the past five years we have described a component from cytoplasmic extracts from C. neoformans which inhibits the phagocytic, mitogenic and immune response in vitro. We have shown that this inhibitory activity is only detected with virulent strains from C. neoformans and is not related to the capsular polysaccharide content. It may constitute a new virulence factor. This immunosuppressive activity could explain the impairment of the host defenses seen in patients with cryptococcosis. At this time we have partially purified the immunosuppressive component using preparative isoelectric focusing with the Rotofor cell. The inhibitory components consist of positively charged proteins that focus at basic pH. Their isoelectric points were 9.0. The pool V with the inhibitory activity will be further purified using electroelution. The long term goals of this proposal are (1) to purify and characterize the immunosuppressive component, (2) to determine the in vitro and the in vivo relevance of this inhibitory component, and (3) to assess the role of this immunosuppressive component on the virulence of C. neoformans.
2. Purification of culture filtrate antigens important for detection of cell mediated immunity in cryptococcosis. Using a rat animal model of pulmonary cryptococcosis we have been able to partially purify antigens from the late fraction of the DEAE-Sephacel column, which induced a strong in vitro immune response of spleen cells from sensitized animals. Further purification of this antigen will allow its use as a skin test antigen in cryptococcosis. The potential of this antigen for development of a vaccine against cryptococcosis is also being evaluated in the laboratory.
3. Under the sponsorship of INDUNIV (Industry-University Research Center) we have been studying the effect of antifungal drugs on host defenses in cryptococcosis. We have tested the following antimycotics in vitro: Amphotericin B, 5-fluorocytosine, ketoconazole, itraconazole, fluconazole and cytofungin. Although none of these antifungals were able to modify the phagocytosis of C. neoformans by rat alveolar macrophages they did at sublethal concentrations increase C. neoformans intracellular killing. Amphotericin B, ketoconazole, itraconazole decrease the mitogenic and immune response in vitro.
4. Under contract with the Ocuppational Safety and Health Administration (OSHA) we have been conducting studies on ennumeration of microorganisms in occupational environments in Puerto Rico. Using the Andersen air sampler we have determined several cases of sick building syndrome in Puerto Rico.

2. Díaz, Ana M., Ph.D. (Associate Professor)
   e-mail:adiaz@rcm.upr.edu
   
   Allergy to mites: Allergens, especially those derived from mites, appear to fill a role of a primary stimulus in the development of asthma, and as a trigger for the exacerbation of symptoms. The mites have been grouped into two broad categories: the stored-products mites and the house dust mites. The question of allergenic cross-reactivity between house dust mites and storage mites is important for diagnosis and hyposensitization. However, the information about putative cross-reactivity leading to cross-sensitization and cross-allerginicity between clinically relevant mite species is a matter of controversy. We are involved in the definition and characterization of species-specific and cross-reactive antigens and allergens from the house mite Dermatophagoides pteronyssinus and the storage mite Blomia tropicalis. Better characterization of these antigens and allergens will have considerable implication for the diagnosis, management and epidemiology of mite-mediated allergies, as well for mite culture and allergen production for use in immunoassays.
   Production of monoclonal antibodies: Our laboratory is engaged in the production of monoclonal antibodies in collaborative projects with other researchers.
3. Espino, Ana M., Ph.D. (Assistant Professor)
   e-mail:aespino@rcm.upr.edu
   Two areas of research interests:

1. Characterization of T and B-cell Epitopes of Multiple Antigenic Peptides for a Fasciola/Schistosoma Cross-Reactive Vaccine
   Evidence to date suggests that in animals chronically infected with F. Hepatica a Th2 response is dominant with IgG1 being the dominant antibody isotype in chronically infected cattle [1], sheep [2, 3], and rats [4]. By contrast, in animals that develop resistance against infection, high levels of IgG2 and IFN- have been observed [5]. This indicates that while Th2 response is associated to susceptibility of infection the Th1-response could be associated to resistance. The identification of parasite antigens which are involved in inducing the Th1 response during infection is crucial for the development of a vaccine against parasite. They have recently reported a novel member of the Fasciola saposin-like / NK-Iysin protein family, termed FhSAP-2, which is highly immunogenic in mice and rabbits. It is a Fasciola / Schistosoma cross-reactive antigen that is expressed at an early stage of F. hepatica infection. In addition, FhSAP-2 exhibit a potent lytic activity on human erythrocytes and peripheral blood mononuclear cells. A detailed structural analysis of FhSAP-2 has shown that contains 6 conserved cysteine residues arranged within 5 amphipathic -helix domains and seven hydrophobic residues in strictly conserved positions. Additionally, computer algorithms applied to primary structure of FhSAP-2 have predicted the existence of several MHC class II complex-binding regions as well as of regions that might from T-cell epitope [16, 17]. Since FhSAP-2 ia a F. hepatica/S. mansoni cross-reactive antigen it is obvious that some of these T-cell epitopes could be F. hepatica/S. mansoni cross-reactive epitopes.
2. Prime DNA / F. hepatica protein-boost immunization of mice and sheep
   Fascioliasis caused by Fasciola hepatica represent a recognized unsolved agricultural problem responsible for economic losses estimated in around US $3 Billion per year to rural agricultural communities and commercial producers worldwide including the United States. Recent reports indicate that F. hepatica is also a major human pathogen and is increasingly recognized as causing significant human diseases, with 2-4 million people infected. Evidence to date suggests that in animals chronically infected with F. hepatica a Th2 response is dominant. IgG1 is the dominant antibody isotype in chronically infected cattle, sheep, and rats. By contrast, in animals that develop resistance against infection high levels of IgG2 and IFN- have been observed. This evidences indicated that while Th2 response is associated to susceptibility of infection, the Th1-response could be associated to resistance. Recently, we reported the molecular cloning and biochemical characterization of a novel F. hepatica antigen termed FhSAP-2, which is Fasciola / Schistosoma cross-reactive antigen that exhibits a potent lytic activity on human PBMC and erythrocytes. They have also shown that animals immunized subcutaneously with rFhSAP-2 emulsified in classic Titer Max adjuvant had significantly less parasite burden, less liver damage and less parasite egg in stools and bile than non-vaccinated animals after challenge with F. hepatica metacercarie. Our previous immunization study in mice showed that animals immunized with three intramuscular (IM) doses of a DNA-FhSAP-2 constructs develop a mixed Th1/Th2 response with slight predominance of Th1 response. Thus, we hypothesize that immunization with an FhSAP-2 DNA construct co-injected with plasmid encoding IL-12 should enhance a direct host cellular immune response to TH1 and increase the protective responses against F. hepatica. They hypothesize that host responses generated by a DNA prime / protein boost vaccination regimen will effectively control and reduce the parasite burden, egg output, or pathologic damage produced by F. hepatica. Given the fact that the heterologous immunity between Fasciola and Schistosoma species has been demonstrated and that FhSAP-2 ia a Fasciola / Schistosoma cross-reactive antigen, it is likely that FhSAP-2 could also induce cross-protection against an Schistosoma challenge infection.

4. Kozek, Wieslaw J., Ph.D. (Associate Professor)
   e-mail:wkozek@rcm.upr.edu
   
   My research interest in Medical Helminthology includes the following themes:

1. Ultrastructure of Nematodes: Application of scanning and transmission electron microscopy to elucidate the ultramicroscopy of adult and larval nematodes and the prokaryotic organisms which they harbor.
2. Symbiosis: Elucidation of the relationship between selected filarial systems and the endoparasitic Wolbachia 'symbionts' which they harbor, attempts to isolate and culture Wolbachia in non-filarial systems.
3. Parasitic signals: Elucidation, in selected model systems, of communication modes between the parasite and its host.
4. Antigenic Analysis of Medically Important Nematodes: Isolation and characterization of helminth antigens which may have serodiagnostic or protective applications.
5. Epidemiology of Zoonoses: Identification and study of the prevalence and geographical distribution of enzootic helminths and other biological agents that have the potential to infect man.

5. Kraiselburd, Edmundo K., Ph.D. (Professor)
   e-mail:ekraiselburd@rcm.upr.edu
   
   Basic Research in Animal Virology is conducted in these areas:

1. Biological and biochemical of Simian Immunodeficiency Virus (SIV) chronically infected cells; studies of SIV latency and expression, and evaluation of defective SIV as possible vaccine candidates.
2. 2) Characterization and evaluation of candidate SIV and Dengue Virus recombinant DNA vaccines produced by our laboratory.
3. 3) Epidemiology Studies: (Laboratory of Clinical Microbiology): Prevalence of Chlamydia, genital Herpes and Papilloma Virus Infections in selected populations.

6. Lavergne, Julio A., Ph.D. (Professor)
   e-mail:jlavergne@rcm.upr.edu
   
   Mechanisms of Apoptosis regulation in HIV-chronically infected human lymphoblastoid cells. Several apoptosis-induction pathways (anti-Fas, TNF, nitric oxide) are being studied to test the hypothesis that HIV-derived proteins (Tat, Vpr) play a significant role in the protection of HIV-integraded cells against apoptosis induction. The relationship of nuclear telomerase activity to apoptosis development in this experimental model is also being examined. Specific aims:

1. To compare telomerase activity and telomere length between Jurkat cells (control) and Jrkat clone J1.1 cells chronically infected with HIV, before and after apoptosis induction.
2. To examine the effect of telomerase inhibition on the apoptosis of J1.1 cells.
3. Dehydrogenase metabolic function of freshly isolated blood cells.
4. To examine the effect of transient blockade of Tat-Vpr expression in apoptosis development of J1.1 cells.

7. Meléndez, Loyda M., Ph.D. (Professor)
   e-mail:lmelendez@rcm.upr.edu
   
   My laboratory is interested in studying the pathogenesis of HIV. I have 17 years of experience in studying HIV and how it affects cell membrance receptor expression by flow cytometry, macrophage function, HIV isolation from patients, and in vitro HIV infection of macrophages. I have also been interested in studying factors from the virus that contribute to virulence, in particular the tropism of the virus. Most recently, in a NIH-NINDS funded project my laboratory has been working with the characterization of macrophage proteins related to cognitive impairment by proteomics using SELDI-TOF. In another NIH-SCORE funded project we are also interested in studying the proteins secreted by placental macrophages that relate to HIV inhibitory activity. These two ongoing NIH funded projects focus on virus factors and host factors that affect HIV transmission and pathogenesis.

8. Robledo, Iraida E., M.S. (Assistant Professor)
   e-mail:irobledo@rcm.upr.edu
   
   Two areas of research interest:

1. Antimicrobial Resistance Mechanisms in Gram\-Negative Bacilli
   Efficacy in the utilization of antibiotics requires a clear understanding of the bacteria resistance mechanism. Beta-lactam resistance in gram-negative bacteria can be multi-faceted and in many cases not fully understood. It is hypothesized that existing as well as novel b-lactamases as undefined resistance mechanisms are responsible for the b-lactam resistance observed in clinical isolates from PR. This hypothesis is based on preliminary data gathered in our laboratory that includes:

1. the phenotypic detection of b-lactam resistance on E. coli and K. pneumoniae isolates obtained from the PR Medical Center Bacteriology Laboratory
2. the epidemiological data of the affected patients. The specific aims are to characterize the b-lactamases and undefined resistance mechanisms produced by E. coli and K. pneumoniae isolates by: 1) identifying at the molecular level specific b-lactamases which includes extended-spectrum b-lactamases (ESBL), AmpC b-lactamases, metallo-b-lactamases (MBL) and carbapenemases which may be responsible for b-lactam resistance, 2) identify changes in the regulation of bacterial efflux and porin genes which can influence antibiotic resistance, and 3) correlate the identified resistance mechanisms with epidemiological data collected on selected E. coli and K. pneumoniae isolates from Puerto Rican hospitals.

2. Antimicrobial susceptibility patterns, epidemiological and genotypical characterization of Helicobacter pylori Isolates from PR
   Infection with Helicobacter pylori (H.p.) is a worldwide public health problem, since it has been recognized as a major cause of gastritis, duodenal ulcer disease, gastric ulcer disease, gastric lymphoma, and possibly gastric cancer. The worldwide emergence of H.p. isolates with combined or multidrug resistances to antibiotics provides the motivation for continued surveillance of H.p. at global, national and regional levels. Several studies have shown that demographic factors and geographical region plays an important role in the reported rates of antibiotic resistance in H.p. and/or in disease outcome. Molecular epidemiological studies have identified a relationship between vacA, cagA and iceA H. pylori-virulence genes with different H.p. genotypes, geographical location, different racial groups, and clinical presentation. Recent published investigations strongly suggest that the 3' variability region of the cagA gene, which has signal transduction function, may be directly associated to clinical disease outcome due to its polymorphisms in its phosphorylation motifs. The aims of this study are (1) to study the antimicrobial susceptibility patterns of a minimum of 100 clinical isolates of H.p. obtained from gastric biopsies of symptomatic Puerto Rican patients and determine if there is an statistical association between antimicrobial susceptibility and specific demographic factors, (2) to assess the predominant H.p. vacA, cagA, cagA variable 3' region and iceA genotypes present in these isolates, (3) to determine the possible association of this genotypes with clinical presentation.
   

9. Rodríguez, Nuri, Ph.D. (Professor)
   e-mail:nrodriguez@rcm.upr.edu
   
   The long term goal of our project is to determine the nature of the signal transduction mechanism(s) involved in the regulation of the expression of dimorphism in fungi using Sporothrix schenckii as a model system. Information concerning the control of dimorphism in these and other fungi lacks a unifying theory. Nevertheless, we have reported that dimorphism in S. schenckii responds to effector molecules controlling cell proliferation and differentiation in other eukaryotic cells. The correct approach to the study of dimorphism is to consider it a proliferative (yeast cell cycle) or proliferative and morphogenetic process (yeast-mycelium transition) possibly subjected to similar contral mechanisms that operate in other eukaryotes. In order to understand the relationship between dimorphism and the signal transduction pathways it is essential that we analyze the molecular constituents of these pathways and study their expression throughout the yeast to mycelium transition and the yeast cell cycle. The proteins involved in signal transduction are many, but at present, our experimental objectives are concerned primarily with protein kinase C, RAS, G-proteins and protein kinase p34cdc2. The experimental objectives of our work are concerned with elucidating the role that these proteins might have on dimorphic transitions in this fungus. This includes establishing the presence these proteins in the fungus through various experimental approaches and a characterization of the role of these proteins in the expression of the dimorphic potential of the fungus.
10. Serrano, Adelfa E., Ph.D. (Professor)
    e-mail:aserrano@rcm.upr.edu
    Molecular Biology and Immunology of Parasites: Molecular basis for multidrug resistance (MDR) in Plasmodia.
    
    Malaria is a disease produced by Plasmodium parasites and is one of the major tropical diseases affecting millions of people and causing significant morbidity and mortality yearly. The major problem in malaria control is the development of parasite resistance to most of the antimalarial drugs available, which has led to a greater incidence of the disease. However, despite the magnitude of the problem, the mechanisms of the parasite drug resistance are not well understood. The goal of our research is the definition, at the molecular level of a mechanism or mechanisms involved in drug resistance. In previous work, we have identified Plasmodium falciparum genes which show homology to multidrug resistance (MDR) genes from other organisms and appear to be involved in parasite drug resistance. Experimental evidence suggests that the gene product of one of these genes may be involved in drug efflux from the parasite, therefore mediating drug resistance. The putative role of this polypeptide is now under investigation, as well as the host immunological responses to this gene product on infected patients who have shown sensitivity or resistance to antimalarial drug treatment. To further evaluate the molecular mechanisms underlying parasite multi-drug resistance, the rodent malaria species, P. berghei and P. yoelii, as well as parasite lines with various patterns of drug sensitivity, are being used as in vivo models of the disease. A better understanding of the mechanisms of drug resistance, together with a better knowledge of the host immune responses in malaria resistance, could help in designing effective drug therapy and could contribute to the developing of a test to detect resistance early during infection.
11. Torres-Bauza, Luis J., Ph.D. (Professor)
    e-mail:ljtorres@rcm.upr.edu
    
    My research interests include:

1. 1) Molecular and phenotypic characterization of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates by serotyping aurotyping and antimicrobial susceptibility. Analysis of B-lactamase plasmids is performed by restriction endonucleases, and Southern blotting hybridization.
2. Molecular analysis of B-lactamase plasmids is accomplished by cloning, sequencing and site-directed mutagenesis with special interest in plasmid replication and mobilization. Cloning, restriction endonucleases mapping and DNA sequencing of the 4.9 Kb R-plasmid auxotyping, serotyping and antimicrobial susceptibility of the isolates.
3. Studies in the yeast-to-hyphae conversion of Candida albicans.

12. Vázquez, Guillermo, J., M.D. (Professor)
    Chairman of the Department of Microbiology
    e-mail:gvazquez@rcm.upr.edu
    
    Dr. Guillermo J. Vázquez has been associated with the University of Puerto Rico Medical Sciences Campus as a full-time faculty member since 1979. He has been involved in the following research activities:

1. HIV/AIDS: Principal Investigator of the Adult AIDS Clinical Trials (AACTU) since 1990. The AACTU is an NIAID/DAIDS sponsored clinical research facility under the direction of the Adult AIDS Clinical Trials Group (AACTG). These units are responsible for the accrual and retention of HIV/AIDS subjects interested in participation in clinical research and in gathering meaningful scientific information. The University of Puerto Rico, AACTU site has been extremely successful in achieving its goals, and it is considered one of the best Units. Active recruitment of participants for different protocols is currently being undertaken..
2. Antimicrobial Agents: Clinical evaluation of novel antimicrobial agents for the treatments of bacterial infections.
3. Antimicrobial susceptibility patterns and mechanisms of antimicrobial resistance in Gram-negative bacilli.
4. Epidemiology, susceptibility and pathogenesis of the infections complications of Helicobacter pylori.

Dr. Vázquez is at present, Professor of Medicine and Chairman of the Department of Microbiology and Medical Zoology, University of Puerto Rico Medical Sciences Campus and Investigator at the ACTU.

Emma Fernández-Repollet,Ph.D.

Program Director

RCMI Program

Room 621-A, 6th. floor

Main Building, Medical Sciences Campus

GPO Box 365067

San Juan, PR 00936-5067

Email: efernandez@rcm.upr.edu

Voice (787) 763-9401

FAX (787) 758-5206