Jennine M. Lunetta, MA, PhD

At UCSF, although a Master’s student, I worked alongside PhD graduate students in the Department of Pharmacology.  After nine months as an unpaid volunteer working on my Master’s, I was hired full-time as a Staff Research Associate for Dr. M. Almira Correia in the Department of Pharmacology (40%) and Dr. Paul Ortiz de Montellano in the Department of Pharmaceutical Chemistry (60%).  I worked full-time while I continued to work on my Master’s research. I conducted independent research projects investigating cytochrome P-450, other hemoproteins and acute hepatic porphyria and was responsible for purifying cytochrome P-450 isoenzymes and other proteins for members of the Ortiz de Montellano Laboratory.  For my Master’s research, I examined the isozyme selectivity of the rat liver microsomal cytochrome P-450 suicide-substrate, secobarbital (SB) and elucidated the mechanisms by which SB inactivates cytochrome P-450.  It was determined that the secobarbital mediated inactivation of cytochrome P-450 was selective for P450b and was due to apoprotein alkylation in addition to heme alkylation.  This study showed that inactivation of cytochrome P450b by secobarbital was mechanistically different from that caused by the drug allylisopropylacetamide, and similar to that observed for chloramphenicol.  I received my Master’s degree in Toxicology in 1987.  I worked on other independent research projects during my time at UCSF.  One of these projects, reappraised the mechanism by which glucose ameliorates neurological symptoms and normalizes biochemical abnormalities during attacks of acute intermittent porphyria.  This study provided experimental evidence that elevated tryptophan may be responsible for impaired gluconeogenesis observed during acute intermittent porphyria by causing a block in pyruvate metabolism.  These findings provided a possible explanation why administration of glucose and other sugars to patients with acute intermittent porphyria sometimes results in clinical improvement.

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1. Correia MA, Litman DA, Lunetta JM. Drug-induced modulations of hepatic heme metabolism. Neurological consequences. Ann N Y Acad Sci. 1987;514:248-255. PubMed PMID: 3442388.

2. Lunetta JM. Inactivation of cytochrome P-450 by secobarbital and related analogs. San Jose State University, San Jose, CA: Master's Thesis, unpublished; 1987.

3. Lunetta JM, Sugiyama K, Correia MA. Secobarbital-mediated inactivation of rat liver cytochrome P-450b: a mechanistic reappraisal. Mol Pharmacol. 1989 Jan;35(1):10-17. PubMed PMID: 2913483.

4. Correia MA, Lunetta JM. Acute hepatic heme depletion: impaired gluconeogenesis in rats. Semin Hematol. 1989 Apr;26(2):120-127. PubMed PMID: 2471273.

 

In 1992, I began work as a Laboratory Assistant with Dr. Andrew Clifford in the Department of Nutrition.  During this time, my research focused on studies involving vitamin A, beta-carotene and folic acid.  We developed a solid phase extraction (SPE) method for parallel processing of samples for retinol allowing for sample preparation in the field with a minimum of equipment and technical skills.  The SPE method is faster and easier than past methods for processing a large amount of samples.  We also developed a method for determining retinol and beta-carotene in selected human tissues using high-pressure liquid chromatographic technique.  This method was used to examine whether breast or colon cancer patients had abnormal tissue and blood levels of retinol and β-carotene. It was determined that retinol and beta-carotene concentrations in blood and tissue from cancer patients are the same or higher than those in corresponding tissues of patients without these cancers.  This report questioned the benefit of administering supplemental vitamin A and beta-carotene to breast and colon cancer patients.  We also studied mice consuming a folate-deficient diet and found that folate-deficient mice develop a behavioral activity, called food-spilling, that may have a neurochemical basis in the serotonin and dopamine systems.

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1. Dueker SR, Lunetta JM, Jones AD, Clifford AJ. A parallel processing solid phase extraction protocol for isolating retinol-d-4 and retinol from human plasma for epidemiologic studies. FASEB Journal, (7) A304. The Federation of American Societies for Experimental Biology; 1993.

2. Dueker SR, Lunetta JM, Jones AD, Clifford AJ. Solid-phase extraction protocol for isolating retinol-d4 and retinol from plasma for parallel processing for epidemiological studies. Clin Chem. 1993 Nov;39(11 Pt 1):2318-2322. PubMed PMID: 8222228.

3. Gospe JS, Gietzen DW, Summers PJ, Lunetta JM, Selhub J, Ellis WG, Clifford AJ. Folate depletion and food spilling in mice: neurochemical and neuropathological studies. FASEB Journal, (8) A738. The Federation of American Societies for Experimental Biology; 1994.

4. Lunetta JM, Zulim RA, Dueker SR, Lin Y, Flaig V, Schneider PD, Wolfe BM, Clifford AJ. Method for the simultaneous determination of retinol and beta-carotene concentrations in human tissues and plasma. Anal Biochem. 2002 May 1;304(1):100-109. PubMed PMID: 11969193

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From 1993 to 1996, I worked in the Research Laboratory of Dr. deVere White in the Department of Urology at the University of California, Davis.  My work focused on finding markers of malignant potential in urologic cancers.  We employed flow cytometric technique to measure DNA ploidy in archival tissue obtained from prostate and bladder cancer patients and applied immunohistochemistry to detect p53, bcl-2 and 34be12 proteins in archival specimens from patients with urologic cancers.  One example of our published results determined that the aggressive prostate cancers of black men exhibit a combination of high proliferation and a block in programmed cell death.  These characteristics could contribute to metastasis earlier in the course of disease and the findings provided a partial explanation of why black patients present more frequently with metastatic disease.

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1. Deitch AD, Miller GJ, Lunetta JM, Wertz IE, deVere-White RW. Relationship of DNA ploidy to prostate cancer grade and volume. Journal of Urology, (153S) 270A. American Urological Association; 1995.

2. deVere-White RW, Lunetta JM, Deitch AD, Gandour-Edwards R, Jackson AG, Marshallack J, Kim KB, Kim DY. Racial differences in prostate cancer.. Journal of Urology, (155S) 529A. American Urological Society; 1996.

3. deVere White-RW, Deitch AD, Jackson AG, Gandour-Edwards R, Marshalleck J, Soares SE, Toscano SN, Lunetta JM, Stewart SL. Racial differences in clinically localized prostate cancers of black and white men. J Urol. 1998 Jun;159(6):1979-1982; discussion 1982-1983. PubMed PMID: 9598502.

 

In 1998, I began work on my PhD studying human cytomegalovirus latency with Dr. Jean Wiedeman in the UC Davis Department of Pediatrics, Infectious Disease.  Human cytomegalovirus (HCMV) is a herpesvirus with the ability to establish a persistent latent infection of the infected host. In immunosuppressed individuals, the latent virus can reactivate and cause severe disease.  In fact, the majority of HCMV-related disease is due to reactivation of latent virus.  Little is known about the molecular mechanisms involved in establishing and maintaining the latent stage of the viral life cycle.  The identification and characterization of latency-associated transcripts form an important initial step toward achieving a better understanding of the molecular events involved in HCMV latency.  We were the first to report that cytomegalovirus latency associated transcripts (LAT) are expressed during in vitro productive infection.  This finding was consistent with that observed for LATs in other herpesvirus infections.  Determining the role of the LATs during productive infection may provide insight into their function during latent infection. I received my Doctoral degree in Comparative Pathology in June 2002.

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1. Lunetta JM, Wiedeman JA. Sense transcripts with initiation sites in the promoter enhancer region of the major immediate–early (MIE) region are expressed during HCMV productive infection. 24th International Herpesvirus Workshop Abstract #2.004. 24th International Herpesvirus Workshop; 1999.

2. Lunetta JM, Wiedeman JA. Detection of the latent HCMV genome in a subset of peripheral blood CD14 cells obtained from healthy seropositive individuals. . 25th International Herpesvirus Workshop Abstract #4.22. 25th International Herpesvirus Workshop; 2000.

3. Lunetta JM, Wiedeman JA. Latency-associated sense transcripts are expressed during in vitro human cytomegalovirus productive infection. Virology. 2000 Dec 20;278(2):467-476. PubMed PMID: 11118369.

4. Lunetta JM. Molecular studies of human cytomegalovirus latency. University of California, Davis, CA: Doctoral Dissertation, unpublished; 2002. Available from: http://search.proquest.com/docview/304814297?accountid=14505.

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Since 2002, my research studies have been focused on the soil-inhabiting, dimorphic pathogenic fungus Coccidioides posadasii and coccidioidomycosis, the disease caused by the fungus.  One focus has been to develop a safe and effective vaccine that can protect humans and other susceptible animals against coccidioidomycosis.  The vaccine research has centered on the spherule-endospore subcellular candidate vaccine termed, the coccidioidal T27K vaccine.  The T27K vaccine in combination with the adjuvant, Alum, has been shown to protect mice from lethal intranasal challenge with C. posadasii.  The T27K vaccine was developed as a “more tolerable” (“less-irritating”) alternative to the formalin-killed whole spherule vaccine that failed in human trials due to localized irritation at the immunization site.

 

Since the T27K vaccine is a complex mixture of proteins and carbohydrate that has not been fully characterized, it was concluded that governmental approval of such a vaccine would require that the components be well-defined.  A major effort of the vaccine project was to separate the crude protective T27K vaccine into immunoprotective subfractions and to identify and characterize the protein constituents in the various preparations.  These studies focused on identification, characterization and production of the T27K vaccine’s immunoprotective component(s) with the goal of formulating a protective vaccine devoid of the irritant action of the whole spherule vaccine.  This effort required many different labor-intensive tasks including: 1) growth of spherule-endospore phase 2) preparation of the T27K vaccine, 3) purification of enriched protective subfractions of the vaccine, 4) identification and characterization of the protein constituents of the vaccine and protective subfractions, 5) production of the immunogens by biochemical or molecular genetic techniques, 6) testing of candidate vaccines in mice.

 

One of my significant contributions to the vaccine effort was to identify and characterize the protein constituents of the crude protective T27K vaccine.  Using proteomic and immunoproteomic methods, I have identified 22 proteins in the crude vaccine. In addition, I have isolated, cloned and sequenced a full-length cDNA for 17 of the 22 (5 were already being studied by others).  The cDNA and protein sequences have been deposited into the NCBI Genbank database.  I constructed expression plasmids for the 17 proteins, expressed recombinant versions in a bacterial expression system and purified them using fast protein liquid chromatography.  I have used the purified recombinant proteins to raise antibodies for eight of these proteins. This will allow us to purify the native proteins.  The recombinant and native proteins will be evaluated for their ability to stimulate the immune response and protect against coccidioidomycosis in a mouse model.  Of the 22 proteins identified, 9 of the 22 have been previously characterized in Coccidioides spp., and 12 matched proteins found in the C. posadasii gene index.  Of the 9 proteins that have been previously characterized 4 have been shown by others to be protective antigens (Gel1, ELI-Ag1 and Pmp1 and AmnI).  This finding demonstrated that the crude vaccine is a good source for potential vaccine candidates.

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1. Johnson SM, Kerekes KM, Lunetta JM, Pappagianis D. Characteristics of the protective subcellular coccidioidal T27K vaccine. Ann N Y Acad Sci. 2007 Sep;1111:275-289. PubMed PMID: 17363436.

2. Lunetta JM, Johnson SM, Pappagianis D. Immunoproteomic analysis of the coccidioidal T27K vaccine. 51st Annual Coccidioidomycosis Study Group Meeting, Abstract #8, 2007 March 31; Mesa, AZ, USA.

3. Lunetta JM, Simmons KA, Johnson SM, Pappagianis D. Molecular cloning and expression of a cDNA encoding a Coccidioides posadasii Cu,Zn superoxide dismutase identified by proteomic analysis of the coccidioidal T27K vaccine. Ann N Y Acad Sci. 2007 Sep;1111:181-197. PubMed PMID: 17344523.

4. Lunetta JM, Simmons KA, Johnson SM, Pappagianis D. Molecular cloning and expression of a cDNA encoding a Coccidioides posadasii 1,2-alpha-mannosidase identified in the coccidioidal T27K vaccine by immunoproteomic methods. Ann N Y Acad Sci. 2007 Sep;1111:164-180. PubMed PMID: 17363438.

5. Lunetta JM, Pappagianis D. Purification, characterization and expression analysis of a Class I 1,2-α-mannosidase from the pathogenic fungus Coccidioides posadasii. Self-published, contact the author for details.

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A number of studies have shown that fungal chitinolytic enzymes such as β-N-acetylhexosaminidase and chitinase are induced by chitin or, in some cases, chitin degradation products such as N-acetylglucosamine (GlcNAc).  Based on these studies, I investigated the effect of GlcNAc on chitinolytic enzymes during the parasitic phase of C. posadasii.  It was determined that the addition of GlcNAc to parasitic phase cultures increased chitinolytic enzyme activity, and protein and transcript expression.  During the course of this work, it was noted that GlcNAc induced a previously uncharacterized protein (CFP28).  I isolated a full-length cDNA encoding CFP28 using a combination of RACE and RT-PCR.  The function of the protein is not known, however, it does contain a DOMON-like type 9 carbohydrate binding module (CBM) conserved domain (40-226 aa) and homology modeling produced a match with the C-terminal family 9 CBM of the xylanase 10A from the bacterium, Thermotoga maritima (PDB:1i8a).  The protein may be involved in polysaccharide degradation because most CBMs are appended to polysaccharide degrading enzymes.  In this manner, they concentrate the enzyme on the polysaccharide substrate.  The protein is induced in parallel with the chitinolytic enzymes, chitinase and β-N-acetylhexosaminidase which may indicate a related function.

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1. Lunetta JM, Johnson SM, Pappagianis D. Molecular cloning, characterization and expression analysis of two beta-N-acetylhexosaminidase homologs of Coccidioides posadasii. Med Mycol. 2010 Aug;48(5):744-756. PubMed PMID: 20109094.

2. Lunetta JM, Pappagianis D. Induction of chitinolytic enzymes during spherule-endospore phase of Coccidioides posadasii. 55th Annual Coccidioidomycosis Study Group Meeting; 2011 April 02; Davis, CA, USA.

3. Lunetta JM, Pappagianis D. Identification, molecular characterization, and expression analysis of a DOMON-like type 9 carbohydrate-binding module domain-containing protein of Coccidioides posadasii. Med Mycol. 2014 Aug;52(6):591-609. PubMed PMID: 25023485.

 

Complete List of Published Work in My Bibliography

http://www.ncbi.nlm.nih.gov/myncbi/jennine.lunetta.1/bibliography/43071516/public/?sort=date&direction=ascending