OBJECTIVE: To evaluate innate immune responses of older disabled nursing home residents that may contribute to infectious disease susceptibility, we compared surface markers and signaling efficiency of neutrophils from nursing home residents and community dwelling elders. DESIGN: Observational pilot study. SETTING: Five New Haven, CT area nursing homes and the greater New Haven community. PARTICIPANTS: 15 nursing home residents and 43 community dwelling elders. MEASUREMENTS: Neutrophils were isolated and Toll-like receptor (TLR) and β2 integrin expression on the surface of unstimulated neutrophils were measured via flow cytometry. Chemokine induction was determined by Quantitative PCR. RESULTS: Surface expression of TLR4 was elevated among nursing home residents compared to community dwellers (mean percent positive cells 33.91 [SE 2.75] vs. 15.67 [SE 1.58], p<0.001), while expression of the β2 integrins CD11b and CD18 was significantly lower (mean fluorescent intensity 460.8 [SE 49.1] vs. 632.9 [SE 29.5] for CD11b and 59.6 [SE 7.9] vs. 137.6 [SE 4.6] for CD18, p<0.0001). Neutrophils from nursing home residents produced substantially reduced levels of chemokines at baseline and after stimulation. CONCLUSIONS: Because integrins are an important pathway to phagocyte signaling and contribute to adherence and locomotion of neutrophils, reduced β2 integrin expression may contribute to impaired responses to stimulation and reduced adhesive properties in PMN from nursing home residents. Since integrin CD11b has been shown to negatively regulate TLR4 response, it is plausible that lower levels of CD11b contribute to elevated expression of TLR4.
OBJECTIVE: To evaluate innate immune responses of older disabled nursing home residents that may contribute to infectious disease susceptibility, we compared surface markers and signaling efficiency of neutrophils from nursing home residents and community dwelling elders. DESIGN: Observational pilot study. SETTING: Five New Haven, CT area nursing homes and the greater New Haven community. PARTICIPANTS: 15 nursing home residents and 43 community dwelling elders. MEASUREMENTS: Neutrophils were isolated and Toll-like receptor (TLR) and β2 integrin expression on the surface of unstimulated neutrophils were measured via flow cytometry. Chemokine induction was determined by Quantitative PCR. RESULTS: Surface expression of TLR4 was elevated among nursing home residents compared to community dwellers (mean percent positive cells 33.91 [SE 2.75] vs. 15.67 [SE 1.58], p<0.001), while expression of the β2 integrins CD11b and CD18 was significantly lower (mean fluorescent intensity 460.8 [SE 49.1] vs. 632.9 [SE 29.5] for CD11b and 59.6 [SE 7.9] vs. 137.6 [SE 4.6] for CD18, p<0.0001). Neutrophils from nursing home residents produced substantially reduced levels of chemokines at baseline and after stimulation. CONCLUSIONS: Because integrins are an important pathway to phagocyte signaling and contribute to adherence and locomotion of neutrophils, reduced β2 integrin expression may contribute to impaired responses to stimulation and reduced adhesive properties in PMN from nursing home residents. Since integrin CD11b has been shown to negatively regulate TLR4 response, it is plausible that lower levels of CD11b contribute to elevated expression of TLR4.
Entities:
Keywords:
Community Dwellers; Innate Immunity; Nursing Homes
Authors: David van Duin; Subhasis Mohanty; Venetta Thomas; Sandra Ginter; Ruth R Montgomery; Erol Fikrig; Heather G Allore; Ruslan Medzhitov; Albert C Shaw Journal: J Immunol Date: 2007-01-15 Impact factor: 5.422
Authors: Sébastien Jaillon; Maria Rosaria Galdiero; Davide Del Prete; Marco Antonio Cassatella; Cecilia Garlanda; Alberto Mantovani Journal: Semin Immunopathol Date: 2013-04-04 Impact factor: 9.623
Authors: Feng Qian; Xiaomei Wang; Lin Zhang; Shu Chen; Marta Piecychna; Heather Allore; Linda Bockenstedt; Stephen Malawista; Richard Bucala; Albert C Shaw; Erol Fikrig; Ruth R Montgomery Journal: Aging Cell Date: 2011-11-28 Impact factor: 9.304
Authors: Alexander Panda; Feng Qian; Subhasis Mohanty; David van Duin; Frances K Newman; Lin Zhang; Shu Chen; Virginia Towle; Robert B Belshe; Erol Fikrig; Heather G Allore; Ruth R Montgomery; Albert C Shaw Journal: J Immunol Date: 2010-01-25 Impact factor: 5.422
Authors: Feng Qian; Xiuyang Guo; Xiaomei Wang; Xiaoling Yuan; Shu Chen; Stephen E Malawista; Linda K Bockenstedt; Heather G Allore; Ruth R Montgomery Journal: Aging (Albany NY) Date: 2014-02 Impact factor: 5.682
Authors: Daisy Wilson; William Drew; Alice Jasper; Helena Crisford; Peter Nightingale; Paul Newby; Thomas Jackson; Janet M Lord; Elizabeth Sapey Journal: J Gerontol A Biol Sci Med Sci Date: 2020-11-13 Impact factor: 6.053