Heparan sulfates targeting increases MHC class I- and MHC class II-restricted antigen presentation and CD8(+) T-cell response

High antigen-presenting CAF levels correlate with reduced glycosaminoglycan biosynthesis-heparan sulfate/heparin metabolism in immune cells and poor prognosis in esophageal squamous cell carcinoma: Insights from bulk and single-cell transcriptome profiling

In esophageal squamous cell carcinoma (ESCC), the tumor microenvironment (TME) is characterized by a significant accumulation of cancer-associated fibroblasts (CAFs), which play a pivotal role in the host response against tumor cells. While fibroblasts are known to be crucial in the metabolic reprogramming of the TME, the specific metabolic alterations induced by these cells remain largely undefined. Utilizing single-cell RNA sequencing, we have identified a distinct subpopulation of antigen-presenting CAF (apCAF) within ESCC tumors. Our findings reveal that apCAF contribute to adverse patient outcomes by remodeling the tumor metabolic environment. Notably, apCAF modulate the glycosaminoglycan biosynthesis-heparan sulfate/heparin metabolism pathway in T cells, B cells, and macrophages. Disruption of this pathway may facilitate immune evasion by the tumor. These insights underscore the critical role of CAFs in shaping the metabolic landscape of the TME and lay the groundwork for developing therapeutic strategies aimed at enhancing anti-tumor immunity.

An AAV vaccine targeting the RBD of the SARS-CoV-2 S protein induces effective neutralizing antibody titers in mice and canines

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in catastrophic damage worldwide. Accordingly, the development of powerful, safe, easily accessible vaccines with long-term effectiveness is understood as an urgently needed countermeasure against this ongoing pandemic. Guided by this strong promise of using AAVs, we here designed, optimized, and developed an AAV-based vaccines (including AAV-RBD(max), AAV-RBD(wt), AAV-2xRBD, and AAV-3xRBD) that elicit strong immune responses against the RBD domain of the SARS-CoV-2 S protein. These immunogenic responses have proven long-lived, with near peak levels for at least six months in mice. Notably, the sera immunized with AAV-3xRBD vaccine contains powerful neutralizing antibodies against the SARS-CoV-2 pseudovirus. Further evidence proven that potent specific antibodies could also be elicited in canines after vaccination with AAV-3xRBD vaccine.

A Therapeutic Hepatitis B Virus DNA Vaccine Induces Specific Immune Responses in Mice and Non-Human Primates

Despite the availability of an effective prophylactic vaccine for more than 30 years, nearly 300 million people worldwide are chronically infected with the hepatitis B virus (HBV), leading to 1 death every 30 s mainly from viral hepatitis-related cirrhosis and liver cancer. Chronic HBV patients exhibit weak, transient, or dysfunctional CD8⁺ T-cell responses to HBV, which contrasts with high CD8+ T-cell responses seen for resolvers of acute HBV infection. Therefore, a therapeutic DNA vaccine was designed, expressing both HBV core and polymerase proteins, and was sequence optimized to ensure high protein expression and secretion. Although the vaccine, administered intramuscularly via electroporation, had no effect on plasma viral parameters in a mouse model of persistent HBV infection, it did induce robust HBV-specific immune responses in healthy and adeno-associated hepatitis B virus (AAV-HBV) infected mice as well as in healthy non-human primates.

Obtaining anti-type 1 melatonin receptor antibodies by immunization with melatonin receptor-expressing cells

Antibodies (Abs) specific to cell-surface receptors are attractive tools for studying the physiological role of such receptors or for controlling their activity. We sought to obtain such antibodies against the type 1 receptor for melatonin (MT1). For this, we injected mice with CHO cells transfected with a plasmid encoding human MT1 (CHO-MT1-h), in the presence or absence of an adjuvant mixture containing Alum and CpG1018. As we previously observed that the immune response to a protein antigen is increased when it is coupled to a fusion protein, called ZZTat101, we also investigated if the association of ZZTat101 with CHO-MT1-h cells provides an immunogenic advantage. We measured similar levels of anti-CHO and anti-MT1-h Ab responses in animals injected with either CHO-MT1-h cells or ZZTat101/CHO-MT1-h cells, with or without adjuvant, indicating that neither the adjuvant mixture nor ZZTat101 increased the anti-cell immune response. Then, we investigated whether the antisera also recognized murine MT1 (MT1-m). Using cloned CHO cells transfected with a plasmid encoding MT1-m, we found that antisera raised against CHO-MT1-h cells also bound the mouse receptor. Altogether our studies indicate that immunizing approaches based on MT1-h-expressing CHO cells allow the production of polyclonal antibodies against MT1 receptors of different origins. This paves the way to preparation of MT1-specific monoclonal antibodies.