Parker Davis

This week, I wanted to focus on the idea of herd immunity: what it is, how efforts have panned out in the current pandemic, and what the scientific community proposes as we move forward. Like other aspects of the pandemic, the idea of herd immunity is one that has become politically charged, with proponents and…

Thus far in the pandemic, we’ve seen an array of clinical presentations of COVID-19, including reports of SARS-CoV-2-specific T cell responses, severe lymphopenia, cytokine storm, not to mention the swath of completely asymptomatic or mildly symptomatic individuals (Huang et al., 2020; Ju et al., 2020; Kuri-Cervantes et al., 2020; Laing et al., 2020, Yang, Gui,…

As some of the primary surveillance cells of the immune system, dendritic cells and macrophages are often the first immune cells to encounter pathogens in the body. Their role as antigen presenting cells means that they sit at a crucial hub in the initiation of the immune response; as a result, infecting agents have evolved…

Ultimate understanding of our options for treatment and prevention of COVID-19 will come only as a result of our ability to ascertain the functions of the various SARS-CoV-2 genes and how they interact with the host organism. I’ve written previously about some of these interactions (see updates from 6/2 and 6/15), which are involved largely…

As part of the innate immune system, interferons act to initiate the antiviral response in host organisms. While several immune cell types produce and secrete interferons (IFNs) – including natural killer cells, T cells, and macrophages – a subset of dendritic cells known as plasmacytoid dendritic cells (pDCs) are the body’s major producer of type…

Though ACE2 has been identified as the primary mediator of SARS-CoV-2 attachment and entry into host cells, various other molecules have also been implicated in SARS-CoV-2 infection, including the neuropilin-I receptor and CD147 (Zhang et al., 2020; Cantuti-Castelvetri et al., 2020; Wang et al., 2020). Additionally, the molecules CD209 and CD209L (DC-SIGN and L-SIGN, respectively)…

The Human Leukocyte Antigen (HLA) family – the name given to the Major Histocompatibility Complex in humans – is a highly polymorphic gene cluster involved in presentation of foreign antigens to the immune system and, importantly, in graft rejection (Choo, 2007). HLA molecules come in three main types (called, types I, II, and III); type…

Much of the research thus far on the host immune response to SARS-CoV-2 infection has been geared toward the development of novel vaccines, and for this reason has focused largely on the roles of T and B cells in fighting infection. However, another class of immune cells, the so-called “natural killer” cells, are central to…

Though much progress has been made in determining the specific interactions between SARS-CoV-2 infectious particles and host cells (Liang et al., 2020; see updates for week of 6/2/2020), we are only beginning to understand the exact mechanisms of pathogenicity in detail. As part of this ongoing inquiry, Zhang et al. surveyed the four structural proteins…