Department of Cancer Immunology and AIDS
The Department of Cancer Immunology and AIDS investigates
fundamental questions in the development and expression of immune
responses in cancer and autoimmune disease, as well as the closely
related problem of acquired immunodeficiency syndrome (AIDS).
Research goals and themes
Harvey Cantor, MD, Chair
Research goals of the Department include understanding the
requirements for effective innate and adaptive host immune
responses, and the development of adoptive cellular therapies and
vaccines against cancer and AIDS. These efforts are enhanced by
collaborative relationships within Dana-Farber/Harvard Cancer
Center's Cancer Immunology Program, where Kai Wucherpfennig, MD, PhD, and Glenn Dranoff, MD, adjunct member of CIA, (a member of the Department of Medical
Oncology) serve as co-leaders. A cornerstone of the department's
mission is training graduate students and postdoctoral fellows. Two
NIH-funded training grants, led by Department Chair Harvey Cantor, MD, support postgraduate training in cancer
immunology and AIDS research.
Faculty research interests include hematopoiesis and lymphocyte
development; innate immunity; antigen-presenting cells; T-cell
activation; the Th1 response; regulatory T cells; tumor cell
metastasis; cancer vaccines and immunotherapy; human monoclonal
antibody-based immunotherapy; viral entry; mechanisms of HIV
integration and HIV replication and pathogenesis; and AIDS
vaccines.
Hematopoiesis and lymphocyte development
Harald von Boehmer, MD, PhD, studies early steps in T-cell
differentiation. Von Boehmer and colleagues have identified T-cell
precursors in peripheral blood prior to their entry into the
thymus. These circulating T-cell progenitors (CTPs) were found at
the same frequency in Foxn1 (nu/nu) thymus-deficient mice and
wild-type mice, indicating that they were prethymic rather than
postthymic. Thus, CTPs represent committed T-cell precursors
linking extrathymic with intrathymic lymphopoiesis in adult
mice.
A comprehensive understanding of complex biological information systems, including the immune system and nervous system, requires definition of cells that are genetically programmed to suppress signal transmission and inhibit cellular responses. The laboratory of Harvey Cantor has defined a sublineage of regulatory CD8 T cells that are essential to maintain self tolerance. CD8+ Treg are programmed to inhibit the activation and expansion of CD4+ helper T cells; defects in CD8+ Treg result in development of autoimmune disorders, including murine models of lupus, MS and rheumatoid arthritis. Insight into this regulatory T cell subset suggests new therapeutic approaches to autoimmune diseases and cancer.
In the thymus, signaling through the T-cell antigen receptor
leading to elimination (negative selection) or differentiation
(positive selection) of developing thymocytes generates a
self-tolerant T-cell repertoire. Cantor has shown that the
serine-threonine kinase MINK connects the T-cell receptor to a
signaling pathway that mediates negative, but not positive,
selection. Analysis of this pathway indicates that MINK-dependent
elimination of self-reactive thymocytes is associated with
downstream activation of Jun kinase and enhancement of expression
of the pro-apoptotic molecules, Bim and BimEL.
Carl Novina, MD, PhD, studies the role of
microRNAs (miRNAs) in T-cell development and T-cell-mediated immune
responses. They have shown that two particular miRNAs are highly
upregulated during T-cell development in the thymus, but not
expressed or expressed at low levels in mature T cells. Current
efforts are focused on defining the targets of these miRNAs and
their function in normal lymphoid development as well as in
leukemias.
Cancer vaccines and immunotherapy
Using a pancreatic tumor cell model, Shannon Turley, PhD, studies how the activity of
tumor-infiltrating T cells can be increased. Turley is now
examining whether cytokine-cytokine receptor complexes can induce
tumor regression. Dranoff is developing cancer vaccines with
autologous tumor cells engineered to express granulocyte-macrophage
colonystimulating factor (GM-CSF). This approach has been
translated to clinical trials in multiple cancers and has shown
consistent induction of coordinated humoral and cellular immune
responses that effectuated substantial tumor destruction. Dranoff
also showed that some patients who responded to tumor vaccination
or CTLA4 antibody blockade developed high-titer antibodies to the
NKG2D ligand MICA. These reactions contributed to tumor destruction
by antagonizing immune suppression and augmenting antitumor cytotoxicity.
HIV/AIDS research
Studies of mechanisms of HIV-1 integration by Alan Engelman, PhD, unveiled LEDGF, a molecular tether that
targets HIV-1 to integrate evenly along transcription units, as a
critical gene-targeting factor. His work yielded the first
three-dimensional structure of a crucial cell factor bound to a
retroviral enzyme.
Dana Gabuzda, MD, studies molecular mechanisms of the
interaction of retroviruses with T-cell subsets and the important
functional division of labor among subpopulations of monocytes that
mediate inflammatory responses. These studies have interesting
implications in the twin areas of anticancer and antiviral
immunotherapy. Gabuzda also clarified some of the factors
underlying HIV cellular tropism.
Joseph Sodroski, MD, discovered a form of innate intracellular
immunity against retroviruses mediated by members of the tripartite
motif (TRIM) family of proteins. Defining the mechanism by which
endogenous proteins, including human TRIM5a, might be enhanced in
order to restrict HIV-1 infection in macrophages and microglia has
the potential α reverse HIV-1-associated dementia and to have a
tremendous impact on HIV-1-associated neurological disorders.
Ruth Ruprecht, MD, PhD, works on AIDS and cancer vaccines and
recently demonstrated the ability of overlapping peptides to
function as broadly applicable vaccines to defined antigens.
Immune mechanisms in tumor development and autoimmune
disease
Martin Hemler, PhD, developed an integrin CD151-deficient
mouse, which displays impaired tumor-induced angiogenesis and
inhibition of breast cancer growth. Von Boehmer showed that APC
mice, which develop a high frequency of gastrointestinal cancers,
manifest a thymic defect that leads to regulatory T-cell
abnormalities. Turley has generated transgenic mice with NFkappaB
selectively activated or inhibited to examine the impact of
dendritic cell maturation on tumor growth. Koichi Kobayashi, MD,PhD, delineated an important role for Birc1e in the inflammasome. Wucherpfennig determined the first crystal structure of a
T-cell receptor from a human autoimmune disease bound to its
self-peptide/MHC target, revealing an unusual topology of
peptide/MHC binding that may explain why some autoreactive T cells
escape negative selection in the thymus.
Dimitrios Iliopoulos has identified novel microRNA-gene networks
that are essential in human inflammatory diseases, such as ulcerative
colitis, Crohn’s disease and lupus, and in different types of cancer. In
addition, Dr. Iliopoulos laboratory is interested to expedite the cancer
drug discovery process, through integration of genomic and proteomic
data using novel bioinformatic algorithms.
Antiviral monoclonal antibody immunotherapy
Wayne Marasco, MD, PhD, was the first to isolate human
neutralizing Abs against SARS-CoVs. Marasco is currently studying
the structural and functional basis of broad-spectrum
neutralization against avian and human influenza A viruses, with an
eye toward developing a universal vaccine against all influenza viruses.