The role of parity status on cigarette smoke-induced modulation of anti-tumor immune mechanisms

Figures & data

Table 1  Experimental groups of mice and biological parameters evaluated.

Post-exposure timepoint	24–48 hr				5 wk
Parity status	Nulliparous		Parous		Nulliparous		Parous
Treatment	Air	Smoke	Air	Smoke	Air	Smoke	Air	Smoke
Gestational Endpoints
Incidence of pregnancy	NA	NA	x	x	NA	NA	x	x
Litter size	NA	NA	x	x	NA	NA	x	x
Implantation site number	NA	NA	x	x	NA	NA	-	-
Sex ratio	NA	NA	-	-	NA	NA	x	x
Maternal Endpoints
Body and Organ weights	x	x	x	x	-	-	-	-
Pubic symphysis diameter	x	x	x	x	-	-	-	-
Blood and Lavage profiles	x	x	x	x	x	x	x	x
Lung histology	x	x	x	x	x	x	x	x
CTL activity	x	x	x	x	x	x	x	x
Tumor challenge	x	x	x	x	x	x	x	x

(NA) Not applicable.

(x) Endpoint examined.

(-) Endpoint not evaluated.

Table 2  Effect of cigarette smoke exposure on female fertility and gestation.

Treatment	Air	Smoke
Gestational Parameters
Incidence of pregnancy^a	85.70%	73.80%
Litter size^b	7.70 ± 0.42	8.10 ± 0.40
Number of implantation sites^c	7.80 ± 0.65	8.40 ± 1.46
Post-implantation pup loss (%)^d	4.70 ± 2.90	7.10 ± 2.30
Male/Female sex ratio^e	1.10 ± 0.27	1.10 ± 0.20

^a(# of females giving birth to viable pups/# of females paired) X 100; n = 31–36 dams/exposure group; determined from both post-exposure timepoints.

^bValues determined from both post-exposure timepoints represent mean (n = 6–12 dams/exposure group) ± SE.

^cValues determined 24- 48 hr post-parturition represent mean (n = 6–12 dams/exposure group) ± SE.

^d([# implantation sites – # of viable pups born]/# of implantation sites) X 100; values determined 24– 48 hr post-parturition represent mean (n = 5–6 dams/exposure group) ± SE.

^eValues determined 5 wk post-parturition represent mean (n = 6–12 dams/exposure group) ± SE.

Figure 1.  Effect of cigarette smoke (CS) exposure and pregnancy on pubic symphysis diameter. *Significantly increased (p < 0.05) from both virgin exposure groups. Values represent the mean (n = 6 dams/exposure group) ± SE, determined from the 24– 48 hr post-exposure timepoint.

Table 3  Effects of cigarette smoke exposure and parity status on body and lymphoid organ weights determined 24– 48 hr post-parturition.

Parity Status	Nulliparous		Parous
Treatment	Air	Smoke	Air	Smoke
Body Weight (g)	21.20 ± 0.37	20.30 ± 0.80	26.55 ± 0.60**	27.85 ± 0.94**
Spleen Weight (g)	0.080 ± 0.003	0.080 ± 0.004	0.114 ± 0.003^*	0.117 ± 0.006^*
Thymus Weight (g)	0.040 ± 0.001	0.040 ± 0.002	0.017 ± 0.003^*	0.012 ± 0.002^*
Spleen wt/BW^b	3.80 ± 0.14	3.80 ± 0.08	4.30 ± 0.19	4.20 ± 0.11
Thymus wt/BW^b	2.00 ± 0.08	2.10 ± 0.13	0.70 ± 0.10**	0.40 ± 0.07**

^aValues represent the mean (n = 6 mice/exposure group) ± SE.

^bRelative organ wt: [organ weight (mg)/ BW (g)].

^*Significantly different (p < 0.05) from both nulliparous groups.

**Significantly different (p < 0.01) from both nulliparous groups.

Figure 2.  Effects of cigarette smoke (CS) exposure and parity status on lavageable lung cell profiles at (A) 24– 48 hr and (B) 5 wk post-exposure and, blood cell differential counts at (C) 24– 48 hr and (D) 5 wk post-exposure. A total of three slides were counted and 100 cells/slide. Values represent the mean (n = 6–8 mice/exposure group) ± SE. ACNP = Air control nulliparous; CSNP = Cigarette smoke nulliparous; ACP = Air control pregnant; and CSP = Cigarette smoke pregnant.

Figure 3.  Light photomicrographs of alveolar parenchyma from the lungs of filtered air alone- and cigarette smoke (CS)-exposed nulliparous and parous mice 24– 48 hr post-exposure. Alveolar parenchyma is shown from mice in experimental groups ACNP (A), CSNP (B), ACP (C), and CSP (D). A few, widely scattered, histologically normal alveolar macrophages (arrows with open arrowheads) can be seen in the air control mice (A and C). Increased numbers of slightly hypertrophic alveolar macrophages containing phagocytized dark brown/black particles (arrows with closed arrowheads) are apparent in the smoke-exposed groups (B and D). a = alveolar airspace; ad = alveolar duct airspace. No histological features of alveolar inflammation or epithelial proliferation were present in any of the lung sections. Tissues sections were stained with H & E and examined at 100 X magnification.

Figure 4.  Effects of cigarette smoke (CS) and parity status on EL4 cell-induced tumor incidence. *Significantly increased (p < 0.05) from time- and parity-matched air controls. ^#Significantly increased (p < 0.01) from time- and treatment-matched virgin mice. Tumor incidence calculated as ([Number of mice with palpable tumors/Number of mice injected with EL4 cells]) × 100; (n = 8–15 mice injected with EL4 cells/exposure group).

Figure 5.  Effects of cigarette smoke (CS) and parity status on tumor growth rate. *Significantly decreased (p < 0.05) from time-matched air-exposed parous and nulliparous groups. Values represent the mean (n = 3–14 mice/exposure group) ± SE. Values determined from those mice demonstrating palpable tumors. (n) = Number of EL4-injected mice with palpable tumors.

Figure 6.  Effects of cigarette smoke (CS) and parity status on time-to-tumor formation. Values represent the mean (n = 3–14 mice/exposure group) ± SE. Values determined from those mice demonstrating palpable tumors. (n) = Number of EL4-injected mice with palpable tumors.

Figure 7.  Effects of cigarette smoke (CS) and parity status on cytotoxic T-lymphocyte (CTL) activity. *Significantly increased (p < 0.01) from time- and exposure-matched nulliparous groups. ^#Significantly increased (p < 0.01) from time- and parity-matched air control mice. Values represent the mean (n = 6–8 mice/exposure group) ± SE.