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Dr. Isabel M. Gimeno

Dr. Isabel M. Gimeno

Associate Professor, Poultry Health Management
Diplomate, American College of Poultry Veterinarians

Phone: 919.513.6852
Fax: 919.513.6464


Poultry Tumor Diseases Laboratory (PTDL)


Areas of Research/Study

Marek's disease (MD) is a lymphoproliferative disease induced by the alpha-herpesvirus Marek's disease virus (MDV). MDV has evolved towards more virulent forms in the recent decades. The efficacy of MDV vaccines has decreased concomitantly with the increase in virulence of field isolates. Of particular importance, the most commonly utilized vaccine in the USA during the past 20 years (bivalent vaccine including serotypes 2 and 3) does not protect chickens against the most recently isolated strains of MDV, the very virulent plus (vv+/). Attenuated serotype 1 vaccines seem to confer better protection against challenge with vv+/strains. Nonetheless, even serotype 1 vaccines have been shown to have reduced efficacy with time in some European and Asian countries. Because of the great economic impact of Marek's disease and the threat of more virulent MDV strains emerging, the search for more efficient vaccines continues. A major limitation in the development of more efficient vaccines, however, is the lack of information on mechanisms of vaccine immunity. One of the goals of my laboratory is to better understand the mechanisms of Marek's disease vaccine immunity to develop better strategies of control.

Diagnosis of tumor poultry diseases is complex. My laboratory has worked for several years to establish new diagnostic criteria and standardize the use of molecular techniques for the diagnosis of tumor viral diseases. Furthermore, we have developed real time PCR assays that allow early diagnosis and monitoring of vaccination in the field.

In addition to the development of lymphomas, Marek's disease virus induced a variety of neurological syndromes. The pathogenesis of MDV in the nervous system is not fully understood but it is very likely that Marek's disease virus elicit an abnormal immune response leading to the development of autoimmunity. One of the objectives of my laboratory is to elucidate the mechanisms by which MDV induce lesions in the brain and in the peripheral nerves as well as to determine the factors (virus, host and environment) that contribute to the development of MDV-induced neurological syndromes.

One of our current interests is the study of the immunosuppression induced by MDV (MDV-IS). My laboratory has developed a model to evaluate MDV-IS under laboratory conditions. Further studies using this model will allow a better understanding of the mechanisms behind MDV-IS as well as they will aid in the development of detection and control methods.

Professional Experience

Representative Publications

Scientific Papers

Gimeno, I.M., A.L. Cortes, R.F. Silva. (2008) Load of challenge Marek’s disease virus DNA in blood as a criterion for early diagnosis of Marek’s disease tumors. Avian Diseases, 52: 203-208 Gimeno, I.M., R.F. Silva. (2008) Biological function of Marek’s disease virus gene UL41.  Virus Genes, 36: 499-507.Pandiri, A.K.R., I.M. Gimeno, W.M. Reed, L.F. Lee, R.F. Silva, A.M. Fadly. (2008) Distribution of viral antigen gp85 and provirus in various tissues from commercial meat-type and experimental white leghorn line 0 chickens with different subgroup J avian leukosis virus infection profiles. Avian Pathology, 37: 7-13Silva, R.F., I.M. Gimeno. (2007). Oncogenic Marek's disease viruses lacking the 132 base pair repeats can still be attenuated by serial in vitro cell culture passages. Virus genes, 34: 87-90.Witter, R.L., I.M. Gimeno (2006). Susceptibility of adult chickens, with and without prior vaccination, to challenge with Marek’s disease virus. Avian Diseases, 50: 354-365

Lee, L.F., X. Cui, Cui, Z.,  I.M. Gimeno, B. Lupiani, S.M. Reddy. (2005). Characterization of a very Virulent Marek's Disease Virus Mutant Expressing the pp38 Protein from the Serotype 1 Vaccine Strain CVI988/Rispens. Virus Genes, 31: 73-80. Gimeno, I.M., R.L. Witter, A.M. Fadly, R.F. Silva. (2005). Novel methods for the diagnosis of Marek’s disease. Avian Pathology, 34: 332-340.Gimeno, I.M., R.L. Witter, H.D. Hunt, R.F. Silva. (2005). The pp38 gene of Marek's disease virus (MDV) is necessary for cytolytic infection of B cells and maintenance of the transformed state but not for cytolytic infection of the feather follicle epithelium and horizontal spread of MDV. J. Virol., 79:4545-4549.Lupiani, B.M., X. Cui, L.F. Lee, I.M. Gimeno, R.W. Morgan, R. Silva, R.L. Witter, H.J. Kung, S.M Reddy. (2004). Marek’s disease virus encoded Meq gene is involved in transformation of lymphocytes but dispensable for early cytolytic infection. Proceedings of the National Academy of Science USA, 101: 11815-11820.Gimeno, I.M., R.L. Witter, H.D. Hunt, S.M. Reddy, W.M. Reed (2004). Biocharacteristics shared by highly protective vaccines against Marek's disease. Avian Pathology, 33: 59-68.

Book chapters, invited reviews, and slide study sets

Gimeno, I.M. (2004) Future strategies for controlling Marek’s disease. In Marek’s disease. Edited by F. Davison and V. Nair, Elsevier, pp186-199, London, UK.Witter, R.L., I.M. Gimeno, A.M. Fadly. (2004). Differential diagnosis of lymphoid and myeloid tumors in the chicken. American Association of Avian Pathologist (slide study set #27) Gimeno, I.M., R.L. Witter, A. Miles. Marek’s disease. (2004) . American Association of Avian Pathologist (slide study set #26) Gimeno, I.M. Enfermedad de Marek. 2009. In Principios Basicos de Patologia Aviar. A.J.P. Ferreira and L. Revolledo (eds). Guanabara Koogan, Brasil pp. 193-228