Louis J. Picker, M.D.

Biography
Dr. Picker received his B.A. in Bacteriology at UCLA in 1978 and his M.D. degree from UC San Francisco in 1982. Between 1982 and 1986 he did an internship and residency in Anatomic and Clinical Pathology at the Beth Israel Hospital in Boston, MA, including a chief residency in Pathology in 1985/86. In 1986 he became an immunopathology fellow at Stanford Medical School, and stayed on in the Stanford Department of Pathology as a research fellow in Dr. Eugene Butcher's laboratory from 1987 through 1990.

In 1990 Dr. Picker joined the faculty of the Department of Pathology at the University of Texas Southwestern Medical Center at Dallas where he served as a Principal Investigator, Medical Director of the Flow Cytometry and Clinical Immunology Laboratory, and later Co-Director of the Division of Hematopathology and Immunology.

He joined OHSU in 2000 as Associate Director of the VGTI, Director of the Vaccine Program, Professor in the OHSU Pathology Department, and Director of the Pathobiology and Immunology Division of the Oregon National Primate Research Center.

Research Overview

My laboratory works on five interrelated areas of T cell biology in human and non-human primates:

• Fundamental investigation into the physiology of T cell memory and effector responses, including the mechanisms controlling "selection" of the memory repertoire. These studies also investigate the development and consequences of functional differences in cytokine synthesis, homing behavior, and activation threshold among antigen-specific memory T cells, and the mechanisms responsible for memory T cell well being and regeneration.

• Determination of the mechanisms responsible for the immunopathogenesis of AIDS-causing lentiviruses.

• Determination of the basis of protective immunity against chronic human pathogens, particularly Human and Simian Immunodeficiency Virus (HIV/SIV) and Cytomegalovirus (CMV).

• Development of prophylactic and/or therapeutic vaccines against these diseases.

• Mechanisms of T cell reconstitution after HIV-1 infection or bone marrow transplantation. We have developed special expertise in the analysis of antigen-specific memory T cells, and exploit these technologies in the examination of human subjects and rhesus macaque models of chronic viral infection.

Selected References

Waldrop S.L., C.J. Pitcher , D. Peterson, V.C. Maino, and L.J. Picker Determination of antigen-specific memory/effector CD4+ T cell frequencies by flow cytometry: Evidence for a novel, antigen-specific homeostatic mechanism in HIV-associated immunodeficiency. J. Clin. Invest., 99:1739-1750, 1997

Douek, D.C., R.D. McFarland, P.H. Keiser, E.A. Gage, J.M. Massey, B.F. Haynes, M.A. Polis, A.T. Haase, M.B. Feinberg, J.L. Sullivan, B.D. Jamieson, J.A. Zack, L.J. Picker, and R.A. Koup. Changes in thymic output with age and during the treatment of HIV infection. Nature, 396:690-695, 1998.

Pitcher C.J., C. Quittner, D.M. Peterson, M. Connors, R.A. Koup, V.C. Maino, and L.J. Picker. HIV-1 specific CD4+ T cells are detectable in most individuals with active HIV-1 infection, but decline with prolonged viral suppression, Nat. Med., 5:518-525, 1999.

McFarland R.D., D.C. Douek, R.A Koup, and L.J. Picker. Identification of a human recent thymic emigrant phenotype. Proc. Natl. Acad. Sci., USA, 97:4215-4220, 2000.

Betts M.R., Ambrozak, D.A., Douek, D.C., Bonhoeffer, S.E., Brenchley, J.M., Casazza, J.P., Koup, R.A., and Picker, L.J. Analysis of total HIV-specific CD4+ and CD8+ T cell responses: Relationship to viral load in untreated HIV-1 infection, J. Virol., 75:11983-11991, 2001.

Bitmansour A.D., Waldrop S.L., Pitcher C.J., Khatamzas E., Kern F., Maino V.C., and Picker L.J. Clonotypic Structure of the human CD4+ memory T cell response to Cytomegalovirus, J. Immunol., 167:1151-1163, 2001.

Pitcher C.J., Hagen S.I., Walker J.M., Lum R., Mitchell B.L., Maino V.C., Axthelm M.K., and Picker L.J. Development and homeostasis of T cell memory in rhesus macaque, J. Immunol., 168:29-43, 2002.

Bitmansour A.D., Douek, D.C., Maino V.C., and Picker L.J. Direct ex vivo analysis of human CD4+ memory T cell activation requirements at the single clonotype level, J. Immunol., 169:1207-1218, 2002.

Douek D.C., Picker L.J., and Koup R.A.  T cell dynamics in HIV-1 infection.  Annu. Rev. Immunol.  21:265-304, 2003.

Picker LJ, Hagen SI, Lum R, Reed-Inderbitzin EF, Daly, LM, Sylwester, AW, Walker JM, Siess DC, Piatak, Jr., M, Wang C, Allison DB, Maino VC, Lifson JD, Kodama T, and Axthelm MK. Insufficient production and tissue delivery of CD4+ memory T cells in rapidly progressive SIV infection, J. Exp. Med., 200:1299-1314, 2004.