Joseph T. Newman

Antitumor Activity of an Oncolytic Adenoviral-CD40 Ligand (CD154) Transgene Construct in Human Breast Cancer Cells

Purpose: CD40 ligand (CD40L, CD154) plays a central role in immunoregulation and also directly modulates epithelial cell growth and differentiation. We previously showed that the CD40 receptor is commonly expressed in primary breast cancer tissues. In this proof-of-principle study, we examined the breast cancer growth–regulatory activities of an oncolytic adenoviral construct carrying the CD40L transgene (AdEHCD40L). Experimental Design:In vitro and in vivo evaluations were carried out on AdEHCD40L to validate selective viral replication and CD40L transgene activity in hypoxia inducing factor-1α and estrogen receptor–expressing human breast cancer cells. Results: AdEHCD40L inhibited the in vitro growth of CD40+ human breast cancer lines (T-47D, MDA-MB-231, and BT-20) by up to 80% at a low multiplicity of infection of 1. Incorporation of the CD40L transgene reduced the effective dose needed to achieve 50% growth inhibition (ED50) by ∼10-fold. In contrast, viral and transgene expression of AdEHCD40L, as well its cytotoxicity, was markedly attenuated in nonmalignant cells. Intratumoral injections with AdEHCD40L reduced preexisting MDA-MB-231 xenograft growth in severe combined immunodeficient mice by >99% and was significantly more effective (P < 0.003) than parental virus AdEH (69%) or the recombinant CD40L protein (49%). This enhanced antitumor activity correlated with cell cycle blockade and increased apoptosis in AdEHCD40L-infected tumor cells. Conclusions: These novel findings, together with the previously known immune-activating features of CD40L, support the potential applicability of AdEHCD40L for experimental treatment of human breast cancer.

Growth Inhibition of Human Multiple Myeloma Cells by an Oncolytic Adenovirus Carrying the CD40 Ligand Transgene

Purpose: The growth-inhibitory activity of recombinant CD40 ligand (CD40L) is well documented in human multiple myeloma (MM). We examined MM-targeted delivery of CD40L by a conditional replicative oncolytic adenovirus, AdEHCD40L. Experimental Design: The growth-regulatory activity of AdEHCD40L was determined in vitro and in vivo. Differential analysis with AdEHCD40L and parental virus (AdEHNull)–infected cultures allowed the identification of cellular and molecular pathways modulated by the CD40L transgene. Results: Conditional expression of viral E1A and CD40L transgene was shown in human MM lines RPMI 8226 [interleukin (IL)-6 independent] and Kas-6/1 (IL-6 dependent) under hypoxic conditions commonly found in MM in situ. AdEHCD40L inhibited MM cell growth more effectively than AdEHNull. This enhanced growth-inhibitory activity was abrogated by cotreatment with a CD40L antibody. Chemoresistant MM lines (MR20 and LR5) were similarly susceptible to AdEHCD40L treatment. AdEHCD40L induced apoptosis and S-phase cell cycle blockade while uniquely up-regulating the previously described proapoptotic elements tumor necrosis factor–related apoptosis-inducing ligand, Fas, and IL-8. Intratumoral injections of AdEHCD40L reduced the growth of severe combined immunodeficient/hu RPMI 8226 xenografts by >50% compared with 28% reduction by AdEHNull. Adenoviral hexon and CD40L were detected in AdEHCD40L-treated tumors at day 35 after infection primarily in necrotic areas, suggesting viral replicative activity. Conclusions: These findings show that CD40L acts in concert with viral oncolysis to produce MM growth inhibition through activation of cellular apoptosis. The direct growth-inhibitory activity of AdEHCD40L, together with the well-known immune-potentiating features of CD40L, may be clinically applicable for the experimental treatment of MM or plasma cell leukemia.

Photodynamic inactivation of simian immunodeficiency virus

A photodynamic flow system employing a dihematoporphyrin ether (DHE) was tested for its ability to inactivate the in vitro infectivity of simian immunodeficiency virus (SICMac) at 630 +/- 5 nm with a light fluence of 5 J/cm2. Cell-free SIVMac was inactivated by photoactivated hematoporphyrin derivative in a dose-dependent fashion. Since SIVMac is closely related to human immunodeficiency virus type 2 (HIV-2) and we have previously reported the successful photodynamic inactivation of HIV-1 in cell-free medium as well as in whole human blood, this technology has the potential for the eradication of transfusion-associated acquired immunodeficiency diseases caused by the above-mentioned retroviruses.

Photosensitized inactivation of infectious agents for sterilization of red blood cell concentrates and whole blood

More than 10 million units of human blood components are transfused annually in the United States. Although donor screening and testing have greatly lowered the risk of transmission of viral and protozoan infectious agents, additional sterilization procedures which also preserve blood component function would be of significant value. Use of visible-light-range photosensitizers for sterilization of red blood cells is currently being aggressively investigated in laboratory-scale optical-mechanical systems. Both the photochemical sterilization process and the optical-mechanical system must operate without introducing significant alteration in the properties of the red cells. With successful demonstration of the efficacy and safety of these sterilization techniques, implementation in the blood bank setting will require scale-up to optical-mechanical systems capable of handling approximately 50,000 units daily in 500 - 1,000 blood banks in the United States.

Phototherapies: photosensitized inactivation of viral and protozoan infectious agents and potential application in blood banking

More than 10 million units of human blood components are processed annually in the United States. Although donor screening and testing have greatly lowered the risk of transmission of viral and protozoan infectious agents, additional sterilization procedures which also preserve blood component function would be of significant value. Use of UV-A and visible-light-range photosensitizers for sterilization of blood platelets and red blood cells, respectively, is currently being aggressively investigated in laboratory-scale optical-mechanical systems. With successful demonstration of the efficacy and safety of these sterilization techniques, implementation in the blood bank setting will require scale-up to optical-mechanical systems capable of handling approximately 25,000 units daily in 500 - 1,000 blood banks in the United States.

Photodynamic inactivation of blood-borne enveloped viruses

A better understanding of immunological donor-recipient incompatibility has encouraged the use of blood and its components. In 1985, an estimated 10 million units of whole blood were processed by over 800 blood banks in the United States and 14 million units of blood components were transfused. This increase reflects major advances in managing trauma, hemorrhagic and neoplastic disorders, and recipients of bone marrow or solid organ transplants. Use of blood products still involves significant risk to the recipient because of the potential for transmitting infectious agents. Hepatitis B virus (HBV); cytomegalovirus (CMV); Epstein-Barr virus (EBV); human T cell lymphotropic virus, type 1 (HTLV-1); non-A, non-B (NANB) hepatitis virus; human immunodeficiency virus (HIV); malaria; and trypanosomes can be transmitted by blood transfusion. Screening of donors and serologic testing reduce the risk, but these precautions still provide insufficient protection since detectable HIV antibody may not be present during the early stage of infection.A better understanding of immunological donor-recipient incompatibility has encouraged the use of blood and its components. In 1985, an estimated 10 million units of whole blood were processed by over 800 blood banks in the United States and 14 million units of blood components were transfused. This increase reflects major advances in managing trauma, hemorrhagic and neoplastic disorders, and recipients of bone marrow or solid organ transplants. Use of blood products still involves significant risk to the recipient because of the potential for transmitting infectious agents. Hepatitis B virus (HBV); cytomegalovirus (CMV); Epstein-Barr virus (EBV); human T cell lymphotropic virus, type 1 (HTLV-1); non-A, non-B (NANB) hepatitis virus; human immunodeficiency virus (HIV); malaria; and trypanosomes can be transmitted by blood transfusion. Screening of donors and serologic testing reduce the risk, but these precautions still provide insufficient protection since detectable HIV antibody may not be present during...