Multicellular living organisms and unmodified parts thereof and – Nonhuman animal – Transgenic nonhuman animal
Reexamination Certificate
1998-10-07
2001-04-10
Hauda, Karen M. (Department: 1632)
Multicellular living organisms and unmodified parts thereof and
Nonhuman animal
Transgenic nonhuman animal
C800S003000, C800S009000, C800S013000, C800S014000, C435S320100
Reexamination Certificate
active
06215040
ABSTRACT:
BACKGROUND OF THE INVENTION
The etiology of many respiratory diseases has remained unclear in spite of direct attempts to determine factors that lead to pulmonary damage and loss of function. The underlying respiratory inflammation leading to variable airflow limitation and airway hyperresponsiveness to various stimuli in some respiratory diseases can be exacerbated by allergens, respiratory tract infections, or environmental agents. Localized cytokine/chemokine gene expression (King et al.,
Am J. Respir. Cell
&
Mol. Biol.,
14, 319 (1996)), secretion of low molecular weight inflammatory mediators (Henderson,
Ann. Allergy,
72, 272 (1994)), and the recruitment of specific leukocyte cell types (Bentley et al.,
J. Inv. Allerzol. Clin. Immunol.,
4, 222 (1994)) have all been shown to contribute to respiratory inflammation. For example, asthma is a multifactorial syndrome characterized by breathlessness, pulmonary constriction, airway hyperreactivity and mucous accumulation. It is often, but not always associated with allergies (extrinsic) or environmental stimuli, e.g., tobacco smoke.
Many pathophysiological manifestations of asthma are associated with airway infiltration by eosinophils and lymphocytes. This infiltration is mediated by cytokines and chemokines. Leukocyte influx, in turn, has been associated with the development of lung dysfunction, even in nominal cases of asthma. Indeed, the extent of infiltration generally correlates with the severity of disease. Antigen-induced mouse models of pulmonary allergic disease have proved particularly informative in the genetic dissection of inflammatory pathways in the lung. Typically, these models involve sensitization with a specific antigen (e.g., ovalbumin) followed by airborne administration of the same antigen. Sensitized mice treated with aerosolized allergen develop leukocytic infiltrates of the airway lumen dominated by CD4+ lymphocytes and eosinophils. These mice also develop many of the changes pathognomonic of asthma, including airway hyperresponsiveness (AHR) and goblet cell hyperplasia with excessive mucus production.
The cellular signals leading to airway inflammation, eosinophil infiltration, and AHR remain obscure. Lymphocytes, eosinophils, and mast cells have been implicated in the AHR of antigen-challenged mouse models of asthma. SCID mice, which lack both T and B lymphocytes, fail to develop either an airway eosinophilia or bronchial hyperreactivity after ovalbumin sensitization (Corry et al.,
J. Exp. Med.,
183, 109 (1996)). The depletion of CD4+ lymphocytes, either by treatment with anti-CD4 antibodies or MHC Class II gene knock-out, eliminated both eosinophil airway infiltration and AHR in antigen-challenged mice (Garett et al.,
Am. J. Respir. Cell
&
Mol. Biol.,
10, 587 (1994)). In contrast, depletion of CD8+ T lymphocytes with anti-CD8 antibodies had no effect on lung eosinophil infiltration but eliminated AHR (Nakajima et al.,
Am. J. Respir. Cell
&
Mol. Biol.,
10, 587 (1994); Hammelmann et al.,
J. Exp. Med.,
183, 1719 (1996)). Moreover, studies with mast cell deficient mice (W/W
v
) indicated that mast cells were not specifically required for either eosinophil airway infiltration or AHR (Bruselle et al.,
Am. J. Respir. Cell
&
Mol. Biol.,
12, 254 (1995)).
Collectively, the antigen sensitization and challenge mouse models implicate T-lymphocytes as a component of the inflammatory response. Furthermore, IL-4 or IL-5 cytokine gene knock-out studies using aerosolized antigen challenge suggest that IL-4 and IL-5 are each important components of proinflammatory cascades that ultimately result in eosinophil airway infiltration and pathophysiological changes characteristic of asthma (Bruselle et al., supra; Foster et al.,
J. Exp. Med.,
183, 195 (1996)).
To define the role of IL-5 in vivo, Dent et al. (
J. Exp. Med.,
172, 1425 (1990)) prepared transgenic mice in which transcription of a genomic copy of the IL-5 gene was under the transcriptional regulatory influence of the dominant control region (DCR) of the gene encoding human CD2 (a T cell surface antigen). Although Dent et al. showed that serum IL-5 levels were elevated in transgenic mice (Tg5C2), because the CD2 enhancer element is only weakly active in mature peripheral T cells, the elevation in serum IL-5 levels was primarily due to thymocyte expression and not peripheral T cell expression. In contrast, serum IL-5 levels are elevated in parasite infested (
Mesocestroides corti
) or antigen challenged mice as a result of IL-5 expression by peripheral T cells. Moreover, despite the increase in serum IL-5 levels, the Tg5C2 mice showed no symptomatic effects of IL-5 overexpression other than a mild splenomegaly and an eosinophilia accompanying a 7-fold increase in white blood cell (WBC) count.
Tominaga et al. (
J. Exp. Med.,
173, 429 (1991)) disclose that transgenic mice in which a IL-5 cDNA was linked to the mouse metallothionein promoter (Tg-6 mice) demonstrated a peripheral eosinophilia with a 3-fold increase in total WBCs. Serum IL-5 levels in Tg-6 mice were 16,000 pg/ml. The predominant sites of IL-5 expression in these mice were the kidney and liver. These organ sites are not normally associated with the production of IL-5 and thus fail to mimic the necessary microenvironmental cues that occur in peripheral sites. Thus, the lack of significant physiological effects in these mice may be the result of ectopically produced IL-5.
Thus, a need exists for an animal model that constitutively expresses IL-5 in a tissue and/or cell-type specific fashion. Moreover, a need exists for an animal model that constitutively expresses IL-5 in thymocytes and peripheral T cells, or in lung tissue, so as to result in IL-5 induced pathologies.
SUMMARY OF THE INVENTION
The invention provides a transgenic mouse whose cells incorporate a preselected chimeric DNA sequence which is integrated into the genome of the mouse and comprises a thymocyte and/or T cell specific transcription control sequence operatively linked to a DNA segment which encodes interleukin-5. The DNA segment which encodes interleukin-5 lacks endogenous interleukin-5 control sequences which are 5′ to the interteukin-5 coding sequence. The DNA segment is preferably expressed as interleukin-5 so as to result in eosinophil-associated pathologies in the transgenic mouse. Preferably, the interleukin-5 encoded by the DNA segment is expressed in the serum of the transgenic mouse in an amount that is at least about fifty times, more preferably at least about seventy-five times, and even more preferably at least about one hundred times, greater than the amount of interieukin-5 in the serum of a corresponding nontransgenic mouse.
Another embodiment of the invention is a transgenic mouse, the cells of which contain a preselected chimeric DNA sequence comprising a lung specific transcription control sequence operatively linked to a DNA segment which encodes interleukin-5. The preselected chimeric DNA sequence is integrated into the genome of the mouse and expressed as interleukin-5 in an amount which preferably results in eosinophil-associated pathologies. The interleukin-5 encoded by the DNA segment is preferably expressed in the transgenic mouse in an amount that is at least about fifty times, more preferably at least about one hundred times, and even more preferably at least about one thousand times, greater than the amount of interleukin-5 in a corresponding nontransgenic mouse. As described hereinbelow, a transgenic mouse that constitutively expressed IL-5 in lung epithelium resulted in a dramatic accumulation of peribronchial eosinophils and striking pathological changes including expansion of bronchus-associated lymphoid tissue (BALT), goblet cell hyperplasia, epithelial hypertrophy and focal collagen deposits. Surprisingly, these changes were not accompanied by a prominent eosinophil infiltration into the airway lumen. Thus, lung-specific expression of IL-5 alone (i.e., in the absence of antigen-induced pulmonary inflammation) can induce many of the pathologic changes assoc
Lee James J.
Lee Nancy A.
Baker Anne-Marie
Hauda Karen M.
Mayo Foundation for Medical Education and Research
Schwegman - Lundberg Woessner - Kluth
LandOfFree
IL-5 transgenic mouse does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with IL-5 transgenic mouse, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and IL-5 transgenic mouse will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441279