Publications by authors named "Efrain Guzman"

Viral vector-based therapies are effective therapeutics for the correction of several disorders, both in mouse models and in humans. Several pre-clinical studies have demonstrated differences in transduction efficiencies and therapeutic effect between male and female mice dosed with AAV-based gene therapy product candidates. Here, we report gender-specific transduction and transgene expression differences in mice dosed systemically with lentiviral vectors (LVV).

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Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness in the aging population, with vascular endothelial growth factor (VEGF) playing a key role. Treatment with recombinant anti-VEGFs is the current standard of care; however, it is only effective for 1-2 months at a time and requires re-administration. Gene therapy could pave the way for stable, long-term expression of therapeutic anti-VEGF with a single dose, reducing the frequency of treatment and potentially improving clinical outcomes.

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Dendritic cells (DCs) are the most potent antigen presenting cells (APCs). Because of the difficulty in obtaining these cells directly from tissues, different sources of DCs are frequently used for in vitro experimentation and many of their biological and functional characteristics were studied using these systems. Until recently, it was assumed that specific culture conditions polarized the differentiation of either DCs or macrophages (Macs); however, it was shown that some DC culture systems in other species generate heterogeneous cell populations that can be identified according to their CD11c and MHC class II (MHC-II) expression.

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Viruses routinely employ strategies to prevent the activation of innate immune signaling in infected cells. Respiratory syncytial virus (RSV) is no exception, as it encodes two accessory proteins (NS1 and NS2) which are well established to block interferon signaling. However, RSV-encoded mechanisms for inhibiting NF-κB signaling are less well characterized.

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Achieving safe and protective vaccination against respiratory syncytial virus (RSV) in infants and in calves has proven a challenging task. The design of recombinant antigens with a conformation close to their native form in virus particles is a major breakthrough. We compared two subunit vaccines, the bovine RSV (BRSV) pre-fusion F (preF) alone or with nanorings formed by the RSV nucleoprotein (preF+N).

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Antigen presenting cells (APC) of the mononuclear phagocytic system include dendritic cells (DCs) and macrophages (Macs) which are essential mediators of innate and adaptive immune responses. Many of the biological functions attributed to these cell subsets have been elucidated using models that utilize -matured cells derived from common progenitors. However, it has recently been shown that monocyte culture systems generate heterogeneous populations of cells, DCs, and Macs.

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By their very nature, great advances in immunology are usually underpinned by experiments carried out in animal models and inbred lines of mice. Also, their corresponding knock-out or knock-in derivatives have been the most commonly used animal systems in immunological studies. With much credit to their usefulness, laboratory mice will never provide all the answers to fully understand immunological processes.

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There is a need to improve the efficacy of the BCG vaccine against human and bovine tuberculosis. Previous data showed that boosting bacilli Calmette-Guerin (BCG)-vaccinated cattle with a recombinant attenuated human type 5 adenovirally vectored subunit vaccine (Ad5-85A) increased BCG protection and was associated with increased frequency of Ag85A-specific CD4 T cells post-boosting. Here, the capacity of Ag85A-specific CD4 T cell lines - derived before and after viral boosting - to interact with BCG-infected macrophages was evaluated.

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Article Synopsis
  • Bovine respiratory syncytial virus (BRSV) is a significant cause of respiratory illness in calves and is closely related to human RSV, which affects infants.
  • Researchers created a modified version of the BRSV fusion glycoprotein, named "DS2," that maintains its prefusion state and generates a stronger immune response compared to the traditional post-fusion form.
  • Immunized calves showed no signs of infection when exposed to BRSV, demonstrating that the DS2-stabilized immunogen effectively induced protective immunity, which has implications for both bovine health and the development of human RSV vaccines.
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Bovine respiratory syncytial virus (BRSV) is an important cause of respiratory disease in young cattle and is closely related to human RSV (HRSV), which causes severe respiratory disease in infants and the elderly. The RSV genome encodes a small hydrophobic (SH) protein with viroporin activity. Previous studies have shown that recombinant BRSV lacking the SH gene (rBRSVΔSH) is attenuated in the lungs, but not in the upper respiratory tract, of calves and mucosal vaccination with rBRSVΔSH induced long-lasting protective immunity.

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Dendritic cells (DC) are central to the initiation of immune responses, and various approaches have been used to target vaccines to DC in order to improve immunogenicity. Cannulation of lymphatic vessels allows for the collection of DC that migrate from the skin. These migrating DC are involved in antigen uptake and presentation following vaccination.

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Human respiratory syncytial virus (HRSV) is a major cause of lower respiratory tract disease in children and the elderly for which there is still no effective vaccine. We have previously shown that PanAd3-RSV, which is a chimpanzee adenovirus-vectored vaccine candidate that expresses a secreted form of the HRSV F protein together with the N and M2-1 proteins of HRSV, is immunogenic in rodents and nonhuman primates, and protects mice and cotton rats from HRSV challenge. Because the extent to which protection demonstrated in rodent models will translate to humans is unclear, we have exploited the calf model of bovine RSV (BRSV) infection, which mimics HRSV disease in children more closely than do experimental models of unnatural laboratory hosts, to evaluate the safety and efficacy of the PanAd3-RSV vaccine.

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Adenovirus vaccine vectors generated from new viral serotypes are routinely screened in pre-clinical laboratory animal models to identify the most immunogenic and efficacious candidates for further evaluation in clinical human and veterinary settings. Here, we show that studies in a laboratory species do not necessarily predict the hierarchy of vector performance in other mammals. In mice, after intramuscular immunization, HAdV-5 (Human adenovirus C) based vectors elicited cellular and humoral adaptive responses of higher magnitudes compared to the chimpanzee adenovirus vectors ChAdOx1 and AdC68 from species Human adenovirus E.

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Bovine respiratory syncytial virus (BRSV) is an important cause of respiratory disease in young calves. The virus is genetically and antigenically closely related to human (H)RSV, which is a major cause of respiratory disease in young infants. As a natural pathogen of calves, BRSV infection recapitulates the pathogenesis of respiratory disease in man more faithfully than semi-permissive, animal models of HRSV infection.

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Article Synopsis
  • γδ T cells are a small part of the immune system in humans and mice, comprising less than 5% of total lymphocytes, but make up 15-60% in ruminants like cows.
  • Bovine γδ T cells are identified as the primary regulatory T cell subset in peripheral blood, actively secreting IL-10 and proliferating in response to various signals.
  • These γδ T cells can inhibit the proliferation of both CD4(+) and CD8(+) T cells, showing their significant role in immune regulation in cows.
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Bovine respiratory syncytial virus (BRSV) causes inflammation and obstruction of the small airways, leading to severe respiratory disease in young calves. The virus is closely related to human (H)RSV, a major cause of bronchiolitis and pneumonia in young children. The ability to manipulate the genome of RSV has provided opportunities for the development of stable, live attenuated RSV vaccines.

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The γδ T-cell receptor (TCR)-positive lymphocytes are a major circulating lymphocyte population in cattle, especially in young calves. In contrast, human and mice have low levels of circulating γδ TCR(+) T cells (γδ T cells). The majority of the circulating γδ T cells in ruminants express the workshop cluster 1 (WC1) molecule and are of the phenotype WC1(+) CD2(-) CD4(-) CD8(-).

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Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. Current inactivated FMDV vaccines generate short-term, serotype-specific protection, mainly through neutralizing antibody. An improved understanding of the mechanisms of protective immunity would aid design of more effective vaccines.

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Major histocompatibility complex (MHC) class I chain-related (MIC) genes encode molecules that are expressed in response to stress, signalling immune system cells primarily via the activating receptor NKG2D. We investigated the expression of receptors for MIC in lymphocyte subsets found in peripheral blood, lymph node and gut in cattle and demonstrated their presence on natural killer (NK) cells, gammadelta T cells and CD8(+) T cells. Recognition of MIC by NKG2D was formally demonstrated using recombinant protein and an ELISA.

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Article Synopsis
  • Major histocompatibility complex (MHC) class I chain-related (MIC) genes are important for immune responses and are linked to natural killer cell activity.
  • In cattle, researchers identified three MIC genes that are located near non-classical MHC class I genes, similar to the arrangement found in pigs.
  • The study indicates the potential presence of four MIC genes in total and shows variability in the arrangement of these genes across different cattle MHC haplotypes.
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Article Synopsis
  • The cattle major histocompatibility complex (MHC) region includes multiple classical class I genes that are important for antigen presentation and are widely expressed in the body.
  • Researchers identified four nonclassical class I genes in the cattle genome, with three near MIC genes and one near classical class I genes, showing similarities to the pig MHC region arrangement.
  • Gene-specific primers have been designed to study the presence and expression of these genes in various MHC haplotypes and cell types, helping to analyze genetic variation and potential functions of the identified genes.
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Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hooved animals that carries enormous economic consequences. CD8(+) cytotoxic T lymphocytes play an important role in protection and disease outcome in viral infections but, to date, the role of the CD8(+) T-cell immune response to FMDV remains unclear. This study aimed to investigate major histocompatibility complex (MHC) class I-restricted CD8(+) T-cell responses to FMDV in vaccinated and in infected cattle.

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