Professor of Medicine
Public Health Research Institute Center
UMDNJ - New Jersey Medical School
225 Warren Street
Newark, New Jersey 07103

Phone: (973) 854-3210
e-mail: gennarma@umdnj.edu


Research Summary

The Gennaro laboratory studies infection with Mycobacterium tuberculosis, which still causes almost 10 million new cases of tuberculosis (TB) and 2 million deaths per year worldwide (http://www.who.int/tb/). In the immunocompetent host, tubercle bacilli survive expression of adaptive immunity by entering a dormant state. The ensuing stage of infection is asymptomatic (latent infection). About one-third of the world population bears latent M. tuberculosis infection. Most infected persons remain symptom-free for their entire life because their immune system keeps the infection in check. When host immunity falters, however, tubercle bacilli can resume growth and cause disease. The diseased individual sheds tubercle bacilli by coughing or sneezing, thereby transmitting infection to new hosts. Thus, the ability of the microorganism to switch between growth states determines its persistence in the individual host and in the host population.

The switch between replicative and non-replicative states operated by the tubercle bacillus can be investigated by use of in vitro and in vivo models. One area of research in our laboratory is the characterization of the remodeling of the M. tuberculosis transcriptome during infection. We have shown that arrest of M. tuberculosis growth induced by expression of lung immunity in mice is characterized by transcriptional profiles indicative of upregulation of a “dormancy” regulon, changes in respiratory metabolism, rerouting of the carbon flow, and remodeling of the mycobacterial cell wall. Carbon flow rerouting was marked by a switch from metabolic pathways generating energy and biosynthetic precursors in growing bacilli to pathways for storage compound synthesis during growth arrest. We have also seen that growth and persistence of M. tuberculosis in an animal model are associated with different profiles of bacterial antigens, a finding that may have profound implications on new vaccine design. We are currently moving toward genome-scale explorations of the dormant tubercle bacillus to obtain an integrated knowledge of the transcriptional and metabolic changes associated with M. tuberculosis dormancy. Understanding the changing physiology of M. tuberculosis with growth state is key to the development of new drugs and new vaccines.

The outcome of infection with M. tuberculosis is the result of a complex, multicellular interplay that includes the pathogen and both innate and adaptive immune cells. While much is known about transcriptional programs and phenotypes of the individual cell types during infection, the dynamics of their interaction are still poorly understood. This poses a multi-scale problem that spans the cellular and molecular scales, with molecular changes mediating cellular interactions between individual cell types. Studying interactions between two different cell types should provide a relatively tractable system for multi-scale modeling of host-pathogen intercellular networks that departs from most current approaches focusing on a single cell type. A second area of research in our laboratory focuses on the critical interaction between tubercle bacilli and the macrophages that carry them. We hypothesize that any outcome of M. tuberculosis infection reflects reciprocal, likely iterative, interactions by which macrophage and tubercle bacillus change each other’s molecular landscapes and cellular phenotypes. These dynamics are governed by networks of mutual signaling that affect gene expression and downstream cellular activities of host cell and pathogen. The goal of our ongoing work is to uncover and mechanistically understand how these networks govern entry into and exit from latency by combining i) statistical pathway analyses and ii) bottom-up and top-down modeling strategies applied to ex vivo infection of human primary lung macrophages with M. tuberculosis. We expect to identify critical host-pathogen interactions leading to the development of novel therapeutic combination regimens targeting both host and pathogen functions, e.g., by disrupting both arms of an intercellular feedback loop. This program - which utilizes experimental methods, modeling approaches, and bioinformatics - establishes the Gennaro group as one of five NHLBI-funded TB systems biology centers in the United States.

Proper drug treatment not only cures the diseased persons but also drastically decreases the time they are contagious. Thus, early and accurate diagnosis of disease leading to timely treatment is a key element of tuberculosis control. A third area of research in the laboratory is identifying immune biomarkers of M. tuberculosis infection and disease, primarily for diagnostic purposes. Bacterial proteins characterized in our laboratory over the years have become part of multi-protein, diagnostic tests for latent infection and active disease that are commercially available or are being developed. To expand our current knowledge of antibody markers of disease, our laboratory has engaged in proteome-scale interrogation of the antibody response to M. tuberculosis infection and disease. We have adopted a systems immunology approach integrating clinical data and bacterial metabolic and regulatory information with high-throughput detection in human serum of antibodies to the entire M. tuberculosis proteome (~4,000 proteins). We found that sera from worldwide TB suspects recognized approximately 10% of the bacterial proteome. This result defines the M. tuberculosis immunoproteome, which is rich in membrane-associated and extracellular proteins. Additional analyses revealed that during active tuberculosis (i) antibody responses focused on an approximately 0.5% of the proteome enriched for extracellular proteins, (ii) relative target preference varied among patients, and (iii) responses correlated with bacillary burden. On-going work focuses on evaluating the diagnostic potential of TB-associated proteins identified by the proteome screen and to investigate the cellular basis of the dynamics of the antibody response during the evolution of the disease.





Recent Articles

Pine R., Bushkin Y., and Gennaro M.L. (2012) Immunological Biomarkers for Tuberculosis: Potential for a Combinatorial Approach, in Systems Biology of Tuberculosis, JJ. McFadden, D. Beste and A. Kierzek, eds., Springer (in press)

Balázsi G., Igoshin O. and Gennaro M.L. (2012) The transcriptional regulatory network of Mycobacterium tuberculosis, in Bacterial Gene Regulation and Transcriptional Networks, M. Madan Babu, ed., Horizon Scientific Press (in press)

Datta P., Shi L., Bibi N., Balázsi G., Gennaro M.L. (2011) Regulation of central metabolism genes of Mycobacterium tuberculosis by parallel feed-forward loops controlled by sigma factor E. J Bacteriol. 193:1154-1160.

Kunnath-Velayudhan S, Gennaro ML. (2011) Immunodiagnosis of tuberculosis: a dynamic view of biomarker discovery. Clin Microbiol Rev. 24:792-805.

Gennaro M.L. and Doherty T.M. (2010) Immunodiagnosis of tuberculosis: new questions, new tools conference 2008. BMC Proceedings 4 (Suppl 3):I1

Shi L., Sohaskey C.D., Pfeiffer C., Datta P., Parks M., McFadden J.J., North R.J., and Gennaro M.L. (2010) Carbon flux rerouting during Mycobacterium tuberculosis growth arrest. Molecular Microbiology. 78(5):1199-1215.

Tiwari A., Bal‡zsi G., Gennaro M.L., Igoshin O.A. (2010) Interplay of multiple feedbacks with post-translational kinetics results in bistability of mycobacterial stress-response. Physical Biology 7(3):036005

Kunnath-Velayudhan S., Salamon H., Wang H.-Y., Davidow A.L., Molina D.M., Huyn V.T., Cirillo D.M., Michel G., Elizabeth A. Talbot E.A., Mark D. Perkins M.D., Philip L. Felgner P.L., Liang X., Gennaro M.L. (2010) Dynamic antibody responses to the Mycobacterium tuberculosis proteome Proc. Natl. Acad. Sci. USA 107:14703-14708.

Hussain S., Malik M., Shi L., Gennaro M.L., Drlica K. (2009) In vitro model of mycobacterial growth arrest using nitric oxide with limited air. Antimicrob Agents Chemother. 53:157-161.

Balázsi G., Heath A.P., Shi L., Gennaro M.L. (2008) The temporal response of the Mycobacterium tuberculosis gene regulatory network during growth arrest. Mol Syst Biol. 4:225-232.

Bothamley G. and Gennaro M.L. (2008). The antibody response to infection with Mycobacterium tuberculosis in TB Handbook, S.H.E. Kaufmann and W. Britton, eds., Wiley-VCH pp. 227-244.

Shi L., Sohaskey C.D., North R.J., and Gennaro M.L. (2008). Transcriptional characterization of the antioxidant response of Mycobacterium tuberculosis in vivo and during adaptation to hypoxia in vitro. Tuberculosis (Edinb.) 88:1-6.

Khan I.H., Ravindran R., Yee J., Ziman M., Lewinsohn D.M., Gennaro M.L., Flynn J.L., Goulding C.W., DeRiemer K., Lerche N.W., Luciw P.A. (2008). Profiling antibodies to Mycobacterium tuberculosis by multiplex microbead suspension arrays for serodiagnosis of tuberculosis. Clin Vaccine Immunol. 15:433-438.

Gennaro ML, Affouf M, Kanaujia GV, Brusasca PN, Mangura B, and Reichman L. (2007). Antibody markers of incident tuberculosis among HIV-infected adults in the USA: a historical prospective study. Int J Tuberc Lung Dis. 2007 Jun;11(6):624-31.

Azzurri A., Kanaujia G.V., Sow O.Y., Bah B., Diallo A., Del Prete G., and Gennaro M.L. (2006). Serological markers of pulmonary tuberculosis and of response to anti-tuberculosis treatment in a patient population in Guinea. Int J Immunopathol Pharmacol. 19:199-208.

Shi L., Sohaskey C.D., Kana B.D., Dawes S., North R.J., Mizrahi V. and Gennaro M.L. (2005). Changes in energy metabolism in Mycobacterium tuberculosis in mouse lung and under in vitro conditions affecting aerobic respiration. Proc. Natl. Acad. Sci. USA 102:15629-34.

Davidow, A., Kanaujia G.V., Shi L., Kaviar, J, Guo, X.D., Sung N., Kaplan G., Menzies D. and
Gennaro M.L. (2005). Antibody profiles characteristic of Mycobacterium tuberculosis infection state. Infect. Immun. 73:6846-6851.

Kanaujia G.V., Lam P.K., Perry S., Brusasca P.N., Catanzaro A., and Gennaro M.L. (2005). Integration of microscopy and serodiagnostic tests to screen for active tuberculosis. Int. J. Tuberc. Lung Dis. 9:1120-1126.

Spencer JS, Kim HJ, Marques AM, Gonzalez-Juarerro M, Lima MC, Vissa VD, Truman RW,
Gennaro ML, Cho SN, Cole ST, and Brennan PJ. (2004). Comparative analysis of B- and T-cell epitopes of Mycobacterium leprae and Mycobacterium tuberculosis culture filtrate protein 10. Infect Immun. 2004 Jun;72(6):3161-70 PMID: 15155617

Lewinsohn DA, Gennaro ML, Scholvinck L, Lewinsohn DM. (2004). Tuberculosis immunology in children: diagnostic and therapeutic challenges and opportunities. Int J Tuberc Lung Dis. 2004 May;8(5):658-74 PMID: 15137550

Goulding CW, Apostol MI, Gleiter S, Parseghian A, Bardwell J, Gennaro M, Eisenberg D. (2004). Gram-positive DsbE proteins function differently from Gram-negative DsbE homologs. A structure to function analysis of DsbE from Mycobacterium tuberculosis. J Biol Chem. 2004 Jan 30;279(5):3516-24. Epub 2003 Nov 03 PMID: 14597624

Shi L., North R, and Gennaro M.L. (2004). Effect of growth state on transcription levels of genes encoding major secreted antigens of Mycobacterium tuberculosis in the mouse lung. Infect Immun. 2004 Apr;72(4):2420-4 PMID: 15039373

Kanaujia GV, Motzel S, Garcia MA, Andersen P, Gennaro ML. (2004). Recognition of ESAT-6 sequences by antibodies in sera of tuberculous nonhuman primates. Clin Diagn Lab Immunol. 2004 Jan;11(1):222-6 PMID: 14715573

Kanaujia GV, Garcia MA, Bouley DM, Peters R, Gennaro ML. (2003). Detection of early secretory antigenic target-6 antibody for diagnosis of tuberculosis in non-human primates. Comp Med. 2003 Dec;53(6):602-6 PMID: 14727807

Silva VM, Kanaujia G, Gennaro ML, Menzies D. (2003). Factors associated with humoral response to ESAT-6, 38 kDa and 14 kDa in patients with a spectrum of tuberculosis. Int J Tuberc Lung Dis 2003 May;7(5):478-84 PMID: 12757050

Rolinck-Werninghaus C, Magdorf K, Stark K, Lyashchenko K, Gennaro ML, Colangeli R, Doherty TM, Andersen P, Plum G, Herz U, Renz H, Wahn U. (2003). The potential of recombinant antigens ESAT-6, MPT63 and mig for specific discrimination of Mycobacterium tuberculosis and M. avium infection. Eur J Pediatr. 2003 Jul;162(7-8):534-6. Epub 2003 Apr 25. PMID: 12715165

Brusasca PN, Peters RL, Motzel SL, Klein HJ, Gennaro ML. (2003). Antigen recognition by serum antibodies in non-human primates experimentally infected with Mycobacterium tuberculosis. Comp Med. 2003 Apr;53(2):165-72 PMID: 12784850

Brown RM, Cruz O, Brennan M, Gennaro ML, Schlesinger L, Skeiky YA, Hoft DF. (2003). Lipoarabinomannan-reactive human secretory immunoglobulin A responses induced by mucosal bacille Calmette-Guerin vaccination. J Infect Dis 2003 Feb 1;187(3):513-7 PMID: 12552438

Shi L, Jung YJ, Tyagi S, Gennaro ML, North RJ. (2003). Expression of Th1-mediated immunity in mouse lungs induces a Mycobacterium tuberculosis transcription pattern characteristic of nonreplicating persistence. Proc Natl Acad Sci USA 2003 Jan 7;100(1):241-6 PMID: 12506197

Goulding CW, Parseghian A, Sawaya MR, Cascio D, Apostol MI, Gennaro ML, Eisenberg D. (2002). Crystal structure of a major secreted protein of Mycobacterium tuberculosis-MPT63 at 1.5-A resolution. Protein Sci 2002 Dec;11(12):2887-93 PMID: 12441386

Chandramuki A, Lyashchenko K, Kumari HB, Khanna N, Brusasca P, Gourie-Devi M, Satishchandra P, Shankar SK, Ravi V, Alcabes P, Kanaujia GV, Gennaro ML. (2002). Detection of antibody to Mycobacterium tuberculosis protein antigens in the cerebrospinal fluid of patients with tuberculous meningitis. J Infect Dis 2002 Sep 1;186(5):678-83 PMID: 12195355

Amadori M, Lyashchenko KP, Gennaro ML, Pollock JM, Zerbini I (2002). Use of recombinant proteins in antibody tests for bovine tuberculosis. Vet Microbiol 2002 Apr 2;85(4):379-89 PMID: 11856587

Brusasca PN, Colangeli R, Lyashchenko KP, Zhao X, Vogelstein M, Spencer JS, McMurray DN, Gennaro ML. (2001). Immunological characterization of antigens encoded by the RD1 region of the Mycobacterium tuberculosis genome. Scand J Immunol 2001 Nov;54(5):448-52 PMID: 11696195

Johnson S, Brusasca P, Lyashchenko K, Spencer JS, Wiker HG, Bifani P, Shashkina E, Kreiswirth B, Harboe M, Schluger N, Gomez M, Gennaro ML (2001). Characterization of the secreted MPT53 antigen of Mycobacterium tuberculosis. Infect Immun 2001 Sep;69(9):5936-9 PMID: 11500477

Landowski CP, Godfrey HP, Bentley-Hibbert SI, Liu X, Huang Z, Sepulveda R, Huygen K, Gennaro ML, Moy FH, Lesley SA, Haak-Frendscho M.J. (2001). Combinatorial use of antibodies to secreted mycobacterial proteins in a host immune system-independent test for tuberculosis. J Clin Microbiol 2001 Jul;39(7):2418-24 PMID: 11427548

Lyashchenko KP, Singh M, Colangeli R, Gennaro ML. (2000). A multi-antigen print immunoassay for the development of serological diagnosis of infectious diseases. J Immunol Methods. 2000 Aug 28;242(1-2):91-100
Gennaro ML. (2000). Immunologic diagnosis of tuberculosis. Clin Infect Dis. 2000 Jun;30 Suppl 3:S243-6

Gomez M, Johnson S, Gennaro ML. (2000). Identification of secreted proteins of Mycobacterium tuberculosis by a bioinformatic approach. Infect Immun. 2000 Apr;68(4):2323-7

Colangeli R, Spencer JS, Bifani P, Williams A, Lyashchenko K, Keen MA, Hill PJ, Belisle J, Gennaro ML. (2000). MTSA-10, the product of the Rv3874 gene of Mycobacterium tuberculosis, elicits tuberculosis-specific, delayed-type hypersensitivity in guinea pigs. Infect Immun. 2000 Feb;68(2):990-3


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C.V.

M.D. University of Palermo, Italy, M.D., 1977; London School of Hygiene & Tropical Medicine, M.S., 1981; Istituto Superiore di Sanita, Rome, 1978-1986; PHRI, 1984-present.