Time Course Of Immune Response Research Articles

Determining the natural time course of immune response

Determining the natural time course of immune response

Abstract 2255: Enhancing immunogenicity in immunologically cold ER+ breast cancer using estrogen receptor blockade and radiation therapy

Abstract Metastatic, hormone therapy-resistant breast cancers expressing estrogen receptor (ER+) account for the majority of breast cancer deaths. ER+ breast cancers are immunologically “cold” with low tumor mutation burden and few tumor-infiltrating lymphocytes (TILs). Consequently, application of immune checkpoint inhibitors (ICIs) to ER+ breast cancers has not proven effective. Radiation therapy (RT) can increase immune susceptibility of “cold” tumors, but can also increase recruitment of immunosuppressive myeloid-derived suppressor cells (MDSCs) to the radiated tumor microenvironment (TME). Recent studies demonstrate that ER inhibition may antagonize the trafficking and activation of MDSCs in tumors. We hypothesized that combining RT and a selective ER degrader (SERD), fulvestrant, would cooperate to relieve immunosuppression, increase tumor immune susceptibility, and facilitate response to ICIs in a syngeneic murine model of ER+ breast cancer. Using a murine breast cancer model of ER+ breast cancer developed (TC11), we examined effects in vitro and in vivo. In vitro, TC11 cells were treated with 8Gy RT and/or fulvestrant (1uM) to evaluate cell autonomous effects. In vivo, 25,000 TC11 cells were transplanted to caudal mammary fat pads of female FVB/N mice. When tumors reached ~200mm3, mice were randomized and treated. We initially evaluated the time course of immune responses to 8Gy RT in the TC11 TME, euthanizing mice every 5 days up to 20 days after RT. We subsequently treated mice with vehicle, fulvestrant (250mg/kg sc, weekly), 8Gy RT, and fulvestrant+8Gy RT. Flow cytometry was performed on day 5 and day 10 after RT to examine the innate and adaptive immune cell infiltrates, respectively. A therapeutic intervention study was performed using combinations of fulvestrant, 8Gy RT, and/or anti-PDL1 (200µg, ip, at days 3, 6, and 9 after RT). 8Gy RT elicited a type-1 interferon response in TC11 cells in vitro and in vivo; as measured by upregulated expression of Mx1, Pdl1, Oas2, Oas3, Trex1, and IfnB mRNAs peaking at 3-5 days post RT and persisting to day 10 in TC11 tumors. RT increased MDSCs (Ly6C+Ly6G+) in the TC11 TME compared to vehicle or fulvestrant alone in tumors taken at day 5, but MDSCs were reduced in tumors treated with fulvestrant and RT. Together, fulvestrant and RT increased TILs (CD45+) and CD8+ T cells at day 10 compared to vehicle control and single treatments. Preliminary data indicate RT and fulvestrant together primed a greater response to anti-PDL1 ICI compared to single or dual combinations of these treatments. These results demonstrate a cooperative interaction between RT and fulvestrant in favorably modulating the TME and response to ICIs in an immunologically cold, hormone-therapy resistant, murine ER+ breast cancer model. Further study is warranted to determine whether this combination may elicit a more effective in situ vaccine effect compared to RT alone. Citation Format: Amber M. Bates, Kathleen A. O'Leary, Sarah Emma, Erin Nystuen, Elizabeth G. Sumiec, Linda A. Schuler, Zachary S. Morris. Enhancing immunogenicity in immunologically cold ER+ breast cancer using estrogen receptor blockade and radiation therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2255.

Time Course of Immune Response and Immunomodulation During Normal and Delayed Healing of Musculoskeletal Wounds.

Single trauma injuries or isolated fractures are often manageable and generally heal without complications. In contrast, high-energy trauma results in multi/poly-trauma injury patterns presenting imbalanced pro- and anti- inflammatory responses often leading to immune dysfunction. These injuries often exhibit delayed healing, leading to fibrosis of injury sites and delayed healing of fractures depending on the intensity of the compounding traumas. Immune dysfunction is accompanied by a temporal shift in the innate and adaptive immune cells distribution, triggered by the overwhelming release of an arsenal of inflammatory mediators such as complements, cytokines and damage associated molecular patterns (DAMPs) from necrotic cells. Recent studies have implicated this dysregulated inflammation in the poor prognosis of polytraumatic injuries, however, interventions focusing on immunomodulating inflammatory cellular composition and activation, if administered incorrectly, can result in immune suppression and unintended outcomes. Immunomodulation therapy is promising but should be conducted with consideration for the spatial and temporal distribution of the immune cells during impaired healing. This review describes the current state of knowledge in the spatiotemporal distribution patterns of immune cells at various stages during musculoskeletal wound healing, with a focus on recent advances in the field of Osteoimmunology, a study of the interface between the immune and skeletal systems, in long bone fractures. The goals of this review are to (1) discuss wound and fracture healing processes of normal and delayed healing in skeletal muscles and long bones; (2) provide a balanced perspective on temporal distributions of immune cells and skeletal cells during healing; and (3) highlight recent therapeutic interventions used to improve fracture healing. This review is intended to promote an understanding of the importance of inflammation during normal and delayed wound and fracture healing. Knowledge gained will be instrumental in developing novel immunomodulatory approaches for impaired healing.

CD22 Regulates Time Course of Both B Cell Division and Antibody Response

Because pathogens induce infectious symptoms in a time-dependent manner, a rapid immune response is beneficial for defending hosts from pathogens, especially those inducing acute infectious diseases. However, it is largely unknown how the time course of immune responses is regulated. In this study, we demonstrate that B cells deficient in the inhibitory coreceptor CD22 undergo accelerated cell division after Ag stimulation, resulting in rapid generation of plasma cells and Ab production. This finding indicates that CD22 regulates the time course of B cell responses and suggests that CD22 is a good target to shorten the time required for Ab production, thereby augmenting host defense against acute infectious diseases as "universal vaccination."

Modulation of delayed-type hypersensitivity during the time course of immune response to a protein antigen.

Delayed-type hypersensitivity reactions elicited in the footpad of ovalbumin-sensitized mice after challenge with aggregated ovalbumin on day 4 or 8 of immunization are distinct. The former was characterized by a dense mononuclear infiltrate and, macroscopically, the reaction peaked at 48 hr after antigen challenge; the latter was preceded by immediate-type reactions, reached the maximum at 24 hr and faded drastically later. Histologically, oedema and a mixed granulocytic-lymphocytic infiltrate was found at this time-point. Immunoglobulin G1 (IgG1), IgG2a and IgE antibodies were detected only in plasma obtained after 8 days of immunization. Regarding the cytokines produced by draining lymph node cells after in vitro restimulation, interleukin-4 (IL-4) and IL-10 were predominant after 4 days and interferon-gamma and IL-2 after 8 days of immunization. These two types of delayed-type hypersensitivity (DTH) were used to study the influence of antibody-mediated responses on the inductive and effector phases of cell-mediated immunity. The effector phase of DTH was not affected by immediate-type reactions, as abrogation of these reactions by mediators' antagonists on day 8 or induction of passive reactions by transfer of immune serum on day 4 did not change the extent or kinetics of either type of DTH. Only transfer, before immunization, of whole or T-cell-enriched spleen cells, but not sera, from hyperimmunized donors (high antibody producers) abolished the induction of pure DTH in 4-day immunized recipient mice and changed their cytokine profile to a T helper 2 type. These results indicate that in a non-polarized immune response to a protein antigen there is initially a bias towards cell-mediated immunity, which is gradually dampened by the development of antibody-mediated immunity.

A comparative study on the immune responses to antigens in PLA and PHB microspheres

Biodegradable microspheres, prepared from various polymers, and containing a model antigen, BSA, were prepared using a double emulsion solvent evaporation method. The microspheres, consisting of poly( l)lactide, poly( d l)lactide, poly( d l)lactide-co-glycolide, polyhydroxybutyrate of various molecular weights and polyhydroxybutyrate-co-valerate, were characterised for their size distribution, drug loading, release kinetics, surface morphology and hydrophobicity. The influence of these properties on the dynamics of the immune response, following i.m. administration, was studied. The hydrophobic nature of polyhydroxybutyrate microspheres, compared with those formed using polylactides was confirmed and the generation of a significant immune response was delayed using these preparations. Also, the time course of immune responses generated using a range of polyhydroxybutyrate molecular weights was examined.

A transthyretin variant (alanine 49) associated with familial amyloidotic polyneuropathy in a French family.

A transthyretin mutation was discovered in a French family with familial amyloidotic polyneuropathy originally described in 1983. The syndrome is of early onset (approximate age 35 to 40) with carpal tunnel syndrome. Death is from cardiac disease. By direct genomic DNA sequencing an A-->G mutation was found in the position corresponding to the first base of transthyretin codon 49. The predicted alanine for threonine substitution in the transthyretin protein was proven by amino acid sequencing of transthyretin isolated from the plasma of an affected subject. Since the DNA mutation does not result in the creation or abolition of a restriction endonuclease recognition site, a new DNA analysis technique was used in which site directed mutagenesis is used to create an RFLP when the introduced mutation is in proximity to the natural mutation. Using a 27 nucleotide mutagenesis primer in the PCR reaction, a new Bg1I site was created on amplification of the variant allele. Using this test, termed PCR-IMRA, four affected members of the family were shown to have the mutation.