title: TNFα and IL-6 Responses to Particulate Matter in Vitro: Variation According to PM Size, Season, and Polycyclic Aromatic Hydrocarbon and Soil Content.
abstract: BACKGROUND
  Observed seasonal differences in particulate matter (PM) associations with human health may be due to their composition and to toxicity-related seasonal interactions.
  
  
  OBJECTIVE
  We assessed seasonality in PM composition and in vitro PM pro-inflammatory potential using multiple PM samples.
  
  
  METHODS
  We collected 90 weekly PM10 and PM2.5 samples during the rainy-warm and dry-cold seasons in five urban areas with different pollution sources. The elements, polycyclic aromatic hydrocarbons (PAHs), and endotoxins identified in the samples were subjected to principal component analysis (PCA). We tested the potential of the PM to induce tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6) secretion in cultured human monocytes (THP-1), and we modeled pro-inflammatory responses using the component scores.
  
  
  RESULTS
  PM composition varied by size and by season. PCA identified two main components that varied by season. Combustion-related constituents (e.g., vanadium, benzo[a]pyrene, benzo[a]anthracene) mainly comprised component 1 (C1). Soil-related constituents (e.g., endotoxins, silicon, aluminum) mainly comprised component 2 (C2). PM from the rainy-warm season was high in C2. PM (particularly PM2.5) from the dry-cold season was rich in C1. Elevated levels of cytokine production were associated with PM10 and C2 (rainy-warm season), whereas reduced levels of cytokine production were associated with PM2.5 and C1 (dry-cold season). TNFα secretion was increased following exposure to PM with high (vs. low) C2 content, but TNFα secretion in response to PM was decreased following exposure to samples containing ≥ 0.1% of C1-related PAHs, regardless of C2 content. The results of the IL-6 assays suggested more complex interactions between PM components and particle size.
  
  
  CONCLUSIONS
  Variations in PM soil and PAH content underlie seasonal and PM size-related patterns in TNFα secretion. These results suggest that the mixture of components in PM explains some seasonal differences in associations between health outcomes and PM in epidemiologic studies.
  
  
  BACKGROUND
  Manzano-León N, Serrano-Lomelin J, Sánchez BN, Quintana-Belmares R, Vega E, Vázquez-López I, Rojas-Bracho L, López-Villegas MT, Vadillo-Ortega F, De Vizcaya-Ruiz A, Rosas Perez I, O'Neill MS, Osornio-Vargas AR. 2016. TNFα and IL-6 responses to particulate matter in vitro: variation according to PM size, season, and polycyclic aromatic hydrocarbon and soil content. Environ Health Perspect 124:406-412; http://dx.doi.org/10.1289/ehp.1409287.
authors.affiliation: Departamento de Investigación Básica, Instituto Nacional de Cancerología, México, DF, México.
authors.forename: Natalia
authors.initials: N
authors.lastname: Manzano-León
authors.forename: Jesús
authors.initials: J
authors.lastname: Serrano-Lomelin
authors.forename: Brisa N
authors.initials: BN
authors.lastname: Sánchez
authors.forename: Raúl
authors.initials: R
authors.lastname: Quintana-Belmares
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Vega
authors.forename: Inés
authors.initials: I
authors.lastname: Vázquez-López
authors.forename: Leonora
authors.initials: L
authors.lastname: Rojas-Bracho
authors.forename: Maria Tania
authors.initials: MT
authors.lastname: López-Villegas
authors.forename: Felipe
authors.initials: F
authors.lastname: Vadillo-Ortega
authors.forename: Andrea
authors.initials: A
authors.lastname: De Vizcaya-Ruiz
authors.forename: Irma Rosas
authors.initials: IR
authors.lastname: Perez
authors.forename: Marie S
authors.initials: MS
authors.lastname: O'Neill
authors.forename: Alvaro R
authors.initials: AR
authors.lastname: Osornio-Vargas
mesh_terms: D000393:Air Pollutants / Q000737:chemistry / Q000633:toxicity*; D045744:Cell Line, Tumor; D002947:Cities; D004731:Endotoxins / Q000633:toxicity; D004784:Environmental Monitoring; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008670:Metals / Q000737:chemistry; D008800:Mexico; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry / Q000633:toxicity*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D004731:Endotoxins; D015850:Interleukin-6; D008670:Metals; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D014409:Tumor Necrosis Factor-alpha