Modelling asthma in macaques: longitudinal changes in cellular and molecular markers

Abstract

The aim of the present study was to determine whether systemic sensitisation and chronic aeroallergen challenge in macaques replicate the classical and emerging immunology and molecular pathology of human asthma.Macaques were immunised and periodically challenged over 2 yrs with house dust mite allergen. At key time-points, serum, bronchoalveolar lavage (BAL) and bronchial biopsies were assayed for genes, proteins and lymphocyte subpopulations relevant to clinical asthma.Immunisation and periodic airway challenge induced changes in immunoglobulin E, airway physiology and eosinophilia consistent with chronic, dual-phase asthma. Sensitisation increased interleukin (IL)-1b and -6 concentrations in serum, and IL-13 expression in BAL cells. Airway challenge increased: early expression of IL-5, -6, -13 and -19, and eotaxin; and variable late-phase expression of IL-4, -5 and -13, and thymus-and activation-regulated chemokine in BAL cells. CD4+ lymphocytes comprised 30% of the CD3+ cells in BAL, increasing to 50% in the late phase. Natural killer T-cells represented ,3% of the CD3+ cells. Corticosteroid treatment reduced serum histamine levels, percentage of CD4+ cells and monocyte-derived chemokine expression, while increasing CD3+ and CD8+ cells in BAL.Sensitisation and periodic aeroallergen challenge of cynomolgus macaques results in physiological, cellular, molecular and protein phenotypes, and therapeutic responses observed in human asthma, providing a model system useful in target and biomarker discovery, and translational asthma research.KEYWORDS: Asthma, corticosteroid treatment, natural killer T-cell, primate model A sthma continues to present a significant unmet medical need [1] and the search for effective asthma drugs with novel mechanisms of action continues. Nonhuman primate models most closely replicate the genetics, physiology, immunology and pathology of the human disease [2][3][4]. The availability of these models uniquely allows examination of both induction of chronic allergy-driven airway inflammation and bronchoconstriction in a controlled setting, as well as identification of key mediators for the maintenance of chronic asthma. Additionally, these models provide a platform to assess pre-clinical safety, and proof of activity and efficacy for novel asthma therapeutics, under conditions that are observed in human patients.Models of asthma have been developed in a variety of common laboratory animals, including guinea pigs, rabbits, rats, mice, sheep, cats, dogs and macaques (see review by BICE et al.[5]).However, there are significant differences in airway architecture and immune responses to chronic allergen between species. Few species develop spontaneous allergic sensitivity to allergens, chronic or prolonged immune and inflammatory responses following pulmonary allergen exposure, progressive worsening of airway responses with repeated antigen challenge, and significant accumulation of lymphoid cells outside the bronchial-associated lymphoid tissue. Murine models have been instrumental ...

Mucosal-Resident T Lymphocytes with Invariant Antigen Receptors

“…In the allergen-induced model of airway hypersensitivity, IL-4 and IL-13 secretion by iNKT cells has been implicated (Meyer et al, 2006;Akbari et al, 2003;Terashima et al, 2008), whereas the ozone-induced model depended upon IL-17A as well as IL-4 and IL-13 . Studies in macaques were consistent with these data in showing that a glycolipid antigen for iNKT cells could induce hypersensitivity, and furthermore, allergen challenge led to iNKT cell infiltration of lung tissue (Matangkasombut et al, 2008;Ayanoglu et al, 2011).…”

Immunolocalization of NLRP3 Inflammasome in Normal Murine Airway Epithelium and Changes following Induction of Ovalbumin-Induced Airway Inflammation

“…An early protective role for inflammasomes might be predicted by the “hygiene hypothesis”, whereby exposure to microbes and their products (such as LPS) early in life is thought to protect against development of asthma, perhaps by a skewing of the immune response away from one dominated by Th2 cytokines [9]. However, current evidence would favour a proinflammatory role for IL-1 β since (i) there are increased levels of serum, BALF, and bronchial epithelial IL-1 β in human asthmatics, compared to healthy subjects [10–12], (ii) increase in serum IL-1 β has also been reported in primates [13], (iii) IL-1 β levels were decreased 2-fold in the bronchial epithelium following inhalation of beclomethasone dipropionate (as measured by an immunohistological technique) [14], and (iv) administration of TNF- α and IL-1 β induces airway hyper-reactivity, a feature of asthma [15, 16]. IL-18, another potent pro-inflammatory cytokine whose maturation requires activation of caspase-1 on the inflammasome, is typically considered as a Th1 cytokine due to its effects associated with IFN- γ .…”

Biomarkers of Disease and Treatment in Murine and Cynomolgus Models of Chronic Asthma

“…Towards this goal, we used a house dust mite allergen (HDMA)-induced asthma model in cynomolgus macaques ( Macaca fascicularis ). As previously described, HDMA-sensitized animals present with a Th2 phenotype characterized by airway eosinophilia, bronchial hyperresponsiveness, and goblet cell metaplasia 5,7. Mass spectrometry was performed on BAL fluid from HDMA-sensitized animals 24 hours before or after challenge with HDMA.…”

“…Studies were performed as described 5. Briefly, animals were sensitized to HDMA over a 7.5 month period by intraperitoneal injection of 312 AU Dermatophagoides pteronyssinus extract (Greer Laboratories) absorbed to Imject Alum (Pierce) administered every two weeks until HDMA-specific IgE titers approached levels in control allergic serum, and then at 4-week intervals until aeroallergen challenge.…”