A patient had spurious thrombocytopenia resulting from a mechanism not previously described. Whereas in prior reports the in vitro phenomenon of platelet clumping has been effected by either EDTA‐dependent or temperature‐dependent antibodies capable of direct platelet agglutination, neither the IgG nor the IgM fractions of this patient's serum demonstrated such activity. However, agglutination was produced by incubating allogeneic platelets with the IgG fraction followed by a room temperature incubation with the rheumatoid factor‐positive IgM fraction. The data support a new mechanism for spurious thrombocytopenia resulting from the interaction of a cold‐reactive rheumatoid factor with antiplatelet antibody.

Cigarette smoke is the leading cause of preventable mortality worldwide. This excess death is attributable to an increased risk of acquiring a variety of conditions, including chronic respiratory/cardiovascular diseases and various types of cancer. Smokers are additionally predisposed to develop infectious diseases, notably including pneumonia caused by the influenza virus, one of the most prevalent and burdensome pathogens in existence today. Although cigarette smoke is well known to modulate many aspects of the immune system, the specific mechanisms by which this predisposition is mediated are incompletely understood. Also unclear is the effect of cigarette smoke on responses to intranasal immunization strategies aimed at eliciting immunity against pathogens such as influenza in the upper airways, where protection may substantially contribute to sterilizing immunity. This PhD thesis focused primarily on addressing these knowledge gaps. In the first study, we assessed the effect of cigarette smoke on antibody induction following intranasal immunization in the upper airways of mice, finding that smoke exposure attenuated antigen-specific IgA induction in the upper respiratory tract, reproductive tract, and systemic circulation. In addition, we found that these nasal IgA demonstrated a reduced antigen-binding avidity in the acute post-immunization period. Mechanistically, deficits in nasal IgA were associated with a reduced accumulation of antigen-specific IgA antibody-secreting cells (ASCs) in the nasal mucosa, induction of these cells in nasal-draining lymphoid tissues, and upregulation of molecules critical to ASC homing (vascular cell adhesion molecule-1; VCAM-1) and IgA transepithelial transport (polymeric immunoglobulin receptor; pIgR) in the nasal mucosa. Ultimately, in tandem with recent clinical work published by others, our study strongly suggests that cigarette smoke can attenuate IgA induction in the upper airways, which may have implications for aspects of intranasal vaccine efficacy. Thus, smoking status should be more consistently considered in the design of clinical trials for IgA-oriented intranasal vaccines. The second study did not assess smoking and host defense directly, but rather served to optimize protocols for assessing immunoglobulins in human mucoid respiratory samples as a precursor to future studies in smoking-related disease. In this regard we found that, relative to phosphate-buffered saline (PBS), dithiothreitol (DTT)-based processing of human sputum samples increased total IgA yields, decreased IgE yield, and improved the detection of a specific IgG autoantibody. These findings suggest that processing choices for human mucoid respiratory samples should be made with specific goals in mind as they pertain to antibody isotype(s) of interest. Finally, in the third study we investigated potential mechanisms by which cigarette smoke exposure promotes influenza, given that smokers are at increased risk of acquiring the pathogen, progressing to severe disease, and being admitted to hospital/ICU following infection. In doing so, we found that concurrent smoke exposure increased morbidity, hypoxemia, pulmonary edema, neutrophilia, and ultimately mortality in a mouse model of H1N1 infection. These changes were associated with an increased accumulation of viral (v)RNA in cells independent of any change in the shedding of replication-competent viral particles. Using a novel dysregulation score approach, we found that interleukin (IL)-6 and colony-stimulating factor (CSF)3 expression was highly exacerbated in the lungs and circulation of smoke-exposed, infected mice relative to controls. Supplementation of recombinant (r)CSF3 increased morbidity, hypothermia and edema, while blockade of the cognate receptor (CSF3R) improved alveolar-capillary barrier function. On the cellular level, single cell RNA-sequencing revealed a shift in the distribution of Csf3+ cells towards neutrophils. Finally, deep transcriptional analysis of neutrophils revealed a gene signature that was largely indicative of an exacerbated form of typical disease with select unique regulatory elements. Ultimately, this work identifies potential therapeutic targets (CSF3R signaling, excess vRNA accumulation) for the treatment of cigarette smoke-augmented influenza, and warns against clinical rCSF3 therapy to treat neutropenia during viral infectious disease. In conclusion, the work presented in this PhD dissertation expands our understanding of the relationship between cigarette smoke and antimicrobial host defense as it pertains to both IgA immunity in the upper airways, and the pathogenesis of cigarette smoke-augmented influenza. / Thesis / Doctor of Philosophy (PhD) / Cigarette smoke exposure is well known to have many harmful effects on human health, including through its ability to promote various infectious diseases such as influenza. However, the mechanisms by which it promotes infection are not fully known. This is an important knowledge gap given that over 1.1 billion individuals continue to smoke worldwide, and a large number of people are exposed to the harmful effects of second-hand smoke, both with fatal consequence. The central goal of this thesis was to gain a better understanding of this relationship between cigarette smoke and infectious disease, specifically by assessing how smoke exposure impacts immune responses in the upper and lower airways. In the first study, we found that smoke exposure interferes with the ability to activate immunoglobulin (Ig)A antibody responses in the nasal passages of mice, which may have important implications for human nasal vaccination strategies. The second study investigated different methods with which to best measure antibodies in human respiratory samples. Finally, in the third study we defined a role for a specific molecule, CSF3, in worsening health in a mouse model of concurrent cigarette smoke and influenza infection. Overall, this work provides new insights into the ways in which smoking can increase the risk of respiratory infection, thereby informing the future design and testing of vaccines and treatments for use in our highly smoke-exposed global population.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

The aim of this thesis was to develop and evaluate albumin-based conjugates for their use in radiotherapy and antibody-recruiting therapy which may then be combined to enhance therapeutic efficacy of each monotherapy. The approach taken in order to achieve high tumour uptake of the conjugates and minimize doses to healthy tissues involved the intratumoural administration of therapeutic compounds; a technique which has gained popularity in recent years for the treatment of solid tumours. Despite the promise this method of administration holds, it is often limited by the fast clearance of injected compounds from the tumour. Using albumin-based conjugates allows for the exploitation of the enhanced permeation and retention (EPR) effect which aids in the retention of the compound at the site of interest for longer periods of time, thus allowing the opportunity for enhanced therapeutic efficacy. Bovine serum albumin conjugated with DOTA chelators was first synthesized and found to possess 3.9 ± 0.4 chelates per BSA molecule. Radiolabelling of the compound with lutetium- 177 produced the desired product in radiochemical yields of 74 ±2 % with a radiochemical purity >99%. The stability of the compound was evaluated by monitoring the radiochemical purity over 7 days which was found to be >95% pure over the entirety of the testing period, indicating a stable product. The intratumoural administration of [177Lu]Lu-DOTA-BSA in a triple negative breast cancer (TNBC) tumour model revealed significant tumour retention of 52 ± 12 %ID/g and 35 ± 6 %ID/g at 24 h and 72 h post-injection, respectively, while autoradiography displayed a heterogenous dispersion of the compound throughout the tumour. A multidosing therapy study in which animals received two doses of either 4.44, 5.92, or 7.40 MBq of [177Lu]Lu-DOTA-BSA showed promise, with a strong trend observed between the administration of higher doses and a prolonged lifespan. Histological analysis of tumours excised 7 days post-treatment revealed signs iv of necrosis and apoptosis in tumours treated with 7.40 MBq [177Lu]Lu-DOTA-BSA. These preliminary results prove to be a promising approach for use in combination therapy and may be further optimized to enhance its efficacy as a monotherapy. Next, the in vivo evaluation of DNP-BSA was carried out to assess using an intratumourally administered, albumin-based platform for antibody-recruiting in a triple negative breast cancer model. A preliminary antibody-recruiting study administering 35 nmol DNP-BSA three times per week unfortunately did not induce slowed tumour growth nor did it have an impact on lifespan. Treated mice were also unable to tolerate repeated doses of the antigen which indicated too high of a concentration and/or dosing frequency was used. A tolerability study was then carried out in order to determine a treatment schedule which did not lead to adverse effects. Mice treated once per week with low (9 nmol) to moderate (17 nmol) doses of DNP-BSA did not display toxic effects but unfortunately did not exhibit a therapeutic effect nor any indication that an adaptive immune response was achieved. These results suggest that further optimization is required prior to use in combination therapy and moderate doses (17 nmol) DNP should be used to investigate a treatment schedule which is able to induce antibody recruitment. / Thesis / Master of Science (MSc)

No description available.

Thrombotic disorders include myocardial infarction (MI), acute ischemic stroke (AIS) and venous thromboembolism (VTE), which encompasses pulmonary embolism (PE), and deep vein thrombosis (DVT). To prevent further complications or mortality in patients with MI and AIS, rapid restoration of blood flow is needed to minimize organ damage. Such treatment also is needed in patients with massive PE. Blood flow can be restored mechanically via percutaneous coronary intervention with stent implantation for MI and by thrombectomy in patients with AIS or PE. Alternatively, pharmacological reperfusion can be achieved by systemic administration of plasminogen activators (PAs). PAs convert plasminogen to the fibrinolytic enzyme, plasmin. Plasmin then degrades the clot into soluble fragments. Streptokinase (SK) and urokinase (UK) were the first therapeutic clot dissolving drugs but both lead to excessive bleeding complications because of non-specific effects. Current therapy focuses on clot specific agents such as recombinant tissue-PA (rt-PA) or tenecteplase (TNK), a rt-PA variant. However, there is a risk of intracranial bleeding in at least 1% of patients, which can be fatal or disabling. Thus, a need exists for new strategies to enable safer reperfusion that are not associated with potentially fatal side effects. This study focuses on the therapeutic role of alpha2-antiplasmin (α2AP). α2AP is the primary inhibitor of plasmin. One approach to thrombolysis is to attenuate α2AP with an inhibitory antibody (A2AP IgG). Inhibition of α2AP would enable clot lysis with lower doses of PAs, thereby reducing the risk of bleeding and serving as a safer approach to thrombolytic therapy. We aimed to characterize A2AP IgG and evaluate its effect on fibrinolysis in vitro and in vivo. A2AP IgG1 was selected and developed using phage display and an antibody gene library with human and rabbit α2AP as the antigen. Affinity maturation was performed and the Fc portion of the A2AP IgG1 was subsequently changed to the IgG4 isotype which yielded A2AP IgG4. A2AP IgG4 binds α2AP with 63-fold higher affinity than A2AP IgG1 as determined using surface plasmon resonance (SPR). SDS-PAGE and western blot analysis reveals that both antibodies bind to the plasmin-α2AP (PAP) complex, fibrinogen, and fragment X but not to α2AP; results confirmed by ELISA. In functional studies, A2AP IgG1 significantly reduced plasmin inhibition by α2AP by 5.5-fold. Both A2AP IgG1 and A2AP IgG4 shortened tissue-PA (t-PA)-mediated clot lysis in a concentration dependent manner. A2AP IgG4 was 2.2-fold more potent than A2AP IgG1 in human plasma and 1.4-fold more potent in rabbit plasma. Compared with t-PA or TNK alone, addition of either antibody enhanced the lysis of preformed plasma clots. Combining A2AP IgG4 with 10% of the highest t-PA or TNK dose produced more clot lysis than the highest dose of t-PA or TNK alone. In a rabbit jugular vein thrombosis model, A2AP IgG4 alone produced 20% lysis. When combined with a low dose of TNK, 40% clot lysis resulted, which was significantly greater than the 30% clot lysis observed with a higher dose of TNK. A2AP IgG4 alone or in combination with a lower dose of TNK did not cause significantly more bleeding than the higher dose of TNK alone and did not degrade circulating fibrinogen. Thus, we have shown that by inactivating α2AP, A2AP IgG attenuates α2AP activity, and accelerates clot lysis in vitro and in vivo. This demonstrates that antibody-mediated inhibition of α2AP, enhances thrombolysis and enables use of lower doses of PAs. / Thesis / Master of Science in Medical Sciences (MSMS)

Antibodies represent the largest group of biopharmaceuticals. Due to the nature of their clinical applications, they often need to be produced in large quantities. Plants have distinct advantages of producing large quantities of recombinant proteins, and tobacco is arguably the most promising plant for plant-made-pharmaceuticals (PMP) due to its high biomass yields and robust transformation technology. However, to produce proteins using transgenic tobacco for human applications, purification of the proteins is challenging. On the other hand, Protein A, a bacterial cell wall protein isolated from Staphylococcus aureus that binds to the Fc regions of immunoglobulins, is useful to the isolation and purification of antibodies. An affinity chromatography purification step utilizing Protein A resin introduced early in the purification process can reduce successive unit operations, thereby reducing the overall process cost. However, directly applying tobacco extract to Protein A chromatography columns may be problematic due to the non-specific binding of native tobacco proteins (NTP). In this project, three different Protein A resins, ProSepvA High Capacity, ProSep-vA Ultra, and ProSep Ultra Plus, marketed by Millipore, were studied to provide valuable information for future downstream processes for antibody purification from transgenic tobacco. The efficiency of the post load wash buffer to reduce non-specific binding of NTP to the ProSep A resins were evaluated by altering the ionic strength and pH. Lower salt concentrations of sodium chloride (NaCl) in the post load wash preformed best at reducing the non-specific binding of NTP to the ProSep A resins, while higher salt concentrations were more effective at reducing the amount of NTP contaminants present during elution of the columns. Using a post load wash buffer with an intermediate pH between the binding buffer and the elution buffer was more efficient at eluting our model antibody, human IgG. However, lowering the ionic strength and the pH of the post load wash buffer resulted in a greater presence of IgG prematurely eluting from the ProSep A resins. The non-specific binding of NTP to the resins reduced the dynamic binding capacity (DBC) of the resins after repeated cycles of tobacco extract samples were loaded onto the column. Nevertheless, cleaning the columns with denaturing solutions, such as urea or guanidine hydrochloride, every 8-10 cycles was effective in regenerating the DBC of the resins and prolonging the life cycle of the resins. This is important to evaluating the economic feasibility of directly using Protein A chromatography to recover antibodies from tobacco extract. Of the three Protein A resins studied, ProSep Ultra Plus performed best for antibody purification from tobacco using a PBS wash buffer with a lower ionic strength of 140mM NaCl and an intermediate pH of 5. / Master of Science

As many genome sequencing efforts today are completed, we are now provided with the genetic maps for several organisms, including man. With these maps at hand, the scientific focus is now shifting towards investigations of the functionality of proteins. This task is even more challenging than the genomic field since proteins, in contrast to DNA, do not allow themselves to be specifically probed or amplified by easy and generic methods. However, to achieve knowledge regarding protein function, useful information includes where, when and how much certain proteins are expressed in an organism. Such information can be obtained if protein-specific binding molecules are available as tools. One such class of target specific binders are the antibody molecules, traditionally employed in a broad variety of biotechnical applications, including protein localization studies on both cellular and sub cellular levels. In a first serie of studies, new methodology for recombinant production and purification of antigens for generation of antibodies via immunization routes were investigated. Parallel affinity gene fusion-based expression systems were used for evaluation of different concepts for production of antigen and post-immunization antibody purification. Carefully designed protein antigens from different organisms were produced and used to raise antisera which were affinity purified on their respective antigens to obtain highly specific polyclonal antibodies (monospecific antibodies). One of the constructed expression systems includes an affinity handle, ZSPA-1, previously selected from a combinatorial protein library for its capacity to selectively bind protein A. This allows for convenient, non IgG-dependent, affinity purification of proteins on conventional protein A resins. A strategy where highly target specific antibody preparations could be affinity purified in a more streamlined setup is also presented. By this strategy it was possible to fractionate antibodies showing reactivity to different parts of the antigen into separate fractions. This resulted in affinity purified antibodies showing monospecific but still multi-epitope reactivity. Purified monospecific antibodies were used in different studies including Western blot immunofluorescence and recovery applications. For affinity purification of endogenous target from its native surrounding a selective elution strategy where the recombinant antigen was used to competitively elute the captured target was developed. / QC 20100824

Since being identified as the cause of AIDS in 1983, HIV-1 infection has reached pandemic proportions. Despite public awareness about prevention, the growing incidence of HIV-1 infection and the limitations of current antiretroviral therapy underscore the imperative need for a vaccine. Understanding the basis of an immune response that controls infection or provides sterilizing immunity remains a major goal in the search for effective vaccines or immunotherapies. Research into correlates of immunity to HIV-1 have largely focused on CD8⁺ T cells or neutralising antibodies (NAbs) but to date these responses have not proved effective in containing viral replication in vaccinees who become infected. Natural killer cells (NKs), monocytes (MCs), and neutrophils (PMNs) are cells of the innate immune system with intrinsic cytotoxic function that can be enhanced by antibodies (Abs) in what is termed antibody-dependent cellular cytotoxicity (ADCC). In my studies I investigated the production of PMNs from human stem cells, the elimination of HIV-1 infected cells by these effector cells, the modulation of cellular cytotoxicity by Ab, and characterized how Abs facilitate a potent ADCC response. I developed a novel flow cytometry assay to measure cytotoxic activity against HIV-1 infected CD4⁺ T cells. Using this, effector cells were shown to have different cytotoxic capacities which were enhanced by Ab. Comparing ADCC mediated by patient serum revealed that higher levels correlated with IgG binding to infected cells. I observed no correlation between serum-mediated ADCC and markers of disease progression including patient status, viral RNA load, CD4⁺ T cell count, or NAb titers. The data presented here have implications for acquisition and control of early HIV-1 infection by NKs, MCs, and PMNs prior to activation of an adaptive immune response, at later stages in the presence of HIV-1-specific Abs, and are relevant to vaccine-induced anti- HIV-1 Ab-based effector mechanisms.