Diagnostic Reasoning and Clinical Problem Solving
Cheston B. Cunha, Burke A. Cunha in Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
A pertinent history can be very useful in limiting the DDx to the likely pathogen. For example, if the patient is elderly or has any sort of malignancy, the most likely pathogen presenting as ABM is L. monocytogenes. Since Listeria is an intracellular pathogen, defects in cellular immunity (↓ T-lymphocyte function) predispose to ABM in case of this organism. The case vignette is that of an 68-year-old male (elderly with CLL) (↓ CMI), who is on steroids (↓ CMI). Certainly, Listeria should be included in DDx. A subacute presentation of AVM should also include aseptic meningitis due to medications, e.g., TMP-SMX. Also, if hamster contact results in a “flu-like illness,” which is then followed by AVM presentation, then lymphocytic choriomeningitis (LCM) should be strongly considered.
Order Bunyavirales
Paul Pumpens, Peter Pushko, Philippe Le Mercier in Virus-Like Particles, 2022
According to the latest ICTV issues (Radoshitzky et al. 2019), the Arenaviridae family unites 4 genera with 54 species, where the genus Mammarenavirus contains 40 species including the most familiar and dangerous arenavirus strains, such as Lassa virus (LASV) from the traditional Old World arenavirus group and Guanarito virus (GTOV), Junin virus (JUNV), Machupo virus (MACV), Sabia virus (SABV), and Whitewater Arroyo virus (WWAV) from the traditional New World virus group, as well as Lujo virus (LUJV), which may cause severe hemorrhagic fever syndromes resulting in significant mortality. First, the observed severe cases of disease have introduced the LASV as a reference arenavirus strain to the scientific community (Buckley et al. 1970). Second, one of the reference strains that was the most-studied representative of the family by the theoretical virological and immunological investigations, namely, lymphocytic choriomeningitis virus (LCMV), may cause not only influenza-like syndromes but also severe aseptic meningitis. LCMV exists in both geographic areas but is regarded rather as an Old World virus.
Arenaviruses and Neurovirology
Sunit K. Singh, Daniel Růžek in Neuroviral Infections, 2013
Bolivian hemorrhagic fever due to Machupo virus was anecdotally studied due to the less common nature of the infection as compared with Lassa fever. In the report (Kilgore et al. 1997), the two patients treated with immune plasma survived. Likewise, some reports exist that ribavirin may be useful in man with Argentine hemorrhagic fever (Enria and Maiztegui 1994) and is underscored by the effectiveness in primate model (Weissenbacher et al. 1986). Lymphocytic choriomeningitis virus is inhibited in vitro by ribavirin, but there are little data to assess its efficacy in substantial LCM disease but it seemed to be effective in LCM-associated organ transplant infection (Fischer et al. 2006).
Live-attenuated lymphocytic choriomeningitis virus-based vaccines for active immunotherapy of HPV16-positive cancer
Published in OncoImmunology, 2020
Sarah Schmidt, Weldy V. Bonilla, Andrea Reiter, Felix Stemeseder, Theresa Kleissner, Daniel Oeler, Ursula Berka, Ahmed El-Gazzar, Bettina Kiefmann, Sophie C. Schulha, Josipa Raguz, Mohamed Habbeddine, Marilies Scheinost, Xiaoping Qing, Henning Lauterbach, Igor Matushansky, Daniel D. Pinschewer, Klaus K. Orlinger
To date, active immunization has not induced consistent efficacy as cancer immunotherapy in clinical Phase III trials.16-18 The goal of immunotherapy by cancer vaccines is to achieve large numbers of CTLs infiltrating and targeting tumor tissues and to establish memory cells for lasting tumor control. From this perspective, replicating viral vaccines, which can deliver tumor-associated antigens in the context of viral infection, are well suited to fulfill this task. Previously, we have demonstrated the potential of this strategy by generating a stably attenuated, replicating lymphocytic choriomeningitis virus (LCMV)-based vector.19 LCMV, the prototype member of the arenavirus family, was chosen primarily for its ability to elicit potent effector CTL responses, life-long CTL immunity and because LCMV-based vectors have demonstrated the capacity to induce tumor regression in a CD8+ T cell-dependent manner.19,20 In addition, LCMV has low seroprevalence in humans21,22 and the glycosylation of its surface protein renders the host neutralizing Ab response inefficient, which allows for re-administrations of the vector.19,23 The replication-competent, stably attenuated LCMV vector can deliver tumor-associated antigens to professional antigen-presenting cells to induce potent CTL responses and triggers the release of alarmin IL-33 from lymphoid stroma cells resulting in a superior effector CTL response than that induced by replication-deficient LCMV vectors.19
In vivo identification of apoptotic and extracellular vesicle-bound live cells using image-based deep learning
Published in Journal of Extracellular Vesicles, 2020
Jan Kranich, Nikolaos-Kosmas Chlis, Lisa Rausch, Ashretha Latha, Martina Schifferer, Tilman Kurz, Agnieszka Foltyn-Arfa Kia, Mikael Simons, Fabian J. Theis, Thomas Brocker
Upon intravenous injection of MFG-E8-eGFP we performed imaging flow cytometry of fresh tissue cells on an ImageStreamx MarkII imaging cytometer, which allows detection of small particles with high sensitivity [23] and generates detailed images of individual cells [24]. To automatically classify apoptotic vs. EV-decorated (EV+) cells, we developed a convolutional autoencoder (CAE) [25–27], which combines the advantages of traditional feature extraction [28–30] and deep learning [31] for imaging flow cytometry. Using this pipeline, we show that MFG-E8-eGFP detects apoptotic as well as EV+ cells in vivo. In untreated mice EV+ haematopoietic cells are readily detectable at low frequencies in vivo. In contrast, irradiation or infection of mice with Lymphocytic choriomeningitis virus (LCMV) dramatically raised the frequencies of apoptotic and EV+ cells. Here, we analysed B cells, DCs and T cells among, which we detected a striking increase of EV+ cells and determined markers present on EVs to determine their origins.
Original antigen sin and COVID-19: implications for seasonal vaccination
Published in Expert Opinion on Biological Therapy, 2022
Original antigenic sin has also been reported with human immunodeficiency virus (HIV) [54]. Haynes and colleagues observed primer-induced antibody suppression using an HIV peptide envelope immunogen in BALB/c mice consistent with original antigenic sin [55]. Interestingly, reversing the sequence of antigen exposure completely overcame HIV primer-induced antibody suppression. The immunologic mechanism has remained opaque, but it is thought that original antigenic sin may be due to faulty cytotoxic T lymphocytes that impair clearance of viruses and may enhance the immune escape of mutant viruses evolving within an individual host [56,57]. Klenerman and colleagues found that mice primed with lymphocytic choriomeningitis virus (LCMV) respond to a subsequent infection by a novel variant with a cytotoxic T cell response directed against the initial epitope rather than against the new variant epitope [58].
Related Knowledge Centers
- Arenavirus
- Aseptic Meningitis
- Encephalitis
- Meninges
- Meningoencephalitis
- Parotid Gland
- Malaise
- Choroid Plexus
- Leukopenia
- Thrombocytopenia