The Humoral Immune Response of Mice Exposed to Manual Metal Arc Stainless Steel-Welding Fumes

Figures & data

TABLE 1A Effect of total MMA-SS on the PFC response to SRBC in splenocytes

Concentration (μg/ml)	Viability (%)	PFC/10^6 cells	Cell Count	PFC/Well
Vehicle	96	1960 ± SE 157	2170 ± SE 191	442 ± SE 48
1.25	96	1052 ± SE 137	1637 ± SE 63	193 ± SE 22
2.5	93	955 ± SE 97	2134 ± SE 208	222 ± SE 35
5	85	238 ± SE 50**	2979 ± SE 160	103 ± SE 17
Positive Control***	80	232 ± SE 33**	2204 ± SE 162	121 ± SE 8**

Values represent the mean ± SE derived from spleens pooled from three animals. Results are based on the average value for six culture wells.

*Significantly different from saline controls, p ≤ 0.05.

**Significantly different from saline controls, p ≤ 0.01.

***Asphalt fume condensate, 0.75 μg/ml, (Heritage Research Group, Indianapolis).

TABLE 1B Effect of soluble MMA-SS on the PFC response to SRBC in splenocytes

Concentration (μg/ml)	Viability (%)	PFC/10^6 cells	Cell Count	PFC/Well
Vehicle	95	1701 ± SE 151	2301 ± SE 164	468 ± SE 7
1.25	94	1429 ± SE 180	1426 ± SE 117	246 ± SE 25
2.5	91	1351 ± SE 190	1722 ± SE 65	290 ± SE 33
5	75	553 ± SE 68	2449 ± SE 93	194 ± SE 22
Positive Control***	80	156 ± SE 47**	2369 ± SE 198	65 ± SE 21

Values represent the mean ± SE derived from spleens pooled from three animals. Results are based on the average value for six culture wells.

*Significantly different from saline controls, p ≤ 0.05.

**Significantly different from saline controls, p ≤ 0.01.

***Asphalt fume condensate, 0.75 μg/ml, (Heritage Research Group, Indianapolis).

TABLE 1C Effect of insoluble MMA-SS on the PFC response to SRBC in splenocytes

Concentration (μg/ml)	Viability (%)	PFC/10^6 cells	Cell Count	PFC/Well
Vehicle	96	1138 ± SE 92	2528 ± SE 155	303 ± SE 34
1.25	96	1122 ± SE 125	2442 ± SE 52	286 ± SE 33
2.5	96	1058 ± SE 117	2803 ± SE 137	303 ± SE 23
5	96	1030 ± SE 253	2822 ± SE 92	359 ± SE 60
Positive Control***	89	392 ± SE 128	3158 ± SE 350	108 ± SE 25

Values represent the mean ± SE derived from spleens pooled from three animals. Results are based on the average value for six culture wells.

*Significantly different from saline controls, p ≤ 0.05.

**Significantly different from saline controls, p ≤ 0.01.

***Asphalt fume condensate, 0.75 μg/ml, (Heritage Research Group, Indianapolis).

TABLE 2 Effect of MMA-SS on body weight (g) and organ weights (mg) in female B⁶C³F¹ mice

		MMA-SS (mg/kg)
Parameter	Vehicle	5	15	20	CP
Body weight (g)	20.1 ± 0.47	21.3 ± 45	21.1 ± 0.46	20.8 ± 0.68	21.9 ± 0.35
Liver (mg)	1125 ± 46	1287 ± 42	1237 ± 40	1146 ± 47	1274 ± 58
% body	5.6 ± 0.1	6.0 ± 0.1	5.9 ± 0.07	5.5 ± 0.25	5.8 ± 0.23
Spleen (mg)	114 ± 7	114 ± 5	116 ± 2	113 ± 4	85 ± 5
% body	0.57 ± 0.02	0.53 ± 0.01	0.55 ± 0.01	0.54 ± 0.02	0.39 ± 0.03
Lungs (mg)	154 ± 4	169 ± 4	198 ± 7**	203 ± 11**	176 ± 4
% body	0.77 ± 0.01	0.80 ± 0.02	0.94 ± 0.03	0.98 ± 0.05	0.80 ± 0.02
Kidneys (mg)	308 ± 12	330 ± 8	339 ± 13	323 ± 8	356 ± 11
% body	1.3 ± 0.03	1.6 ± 0.04	1.6 ± 0.06	1.6 ± 0.04	1.6 ± 0.04
Thymus (mg)	65 ± 5	62 ± 4	79 ± 7	76 ± 9	29 ± 2
% body	0.32 ± 0.02	0.32 ± 0.02	0.36 ± 0.03	0.36 ± 0.04	0.13 ± 0.01

^aB⁶C³F¹ mice treated with vehicle or MMA-SS by pharyngeal aspiration. Animals were dosed four times (once every five days). The mice were immunized 24 hr after the last treatment and sacrificed 4 d later. The mice were weighed and necropsied; and indicated organs were weighed. Values represent mean + SE derived from seven animals in each group. 25 mg/kg of Cyclophosphamide (CP), (% body) = percentage of body weight.

*Significantly different from saline controls, p ≤ 0.05.

**Significantly different from saline controls, p ≤ 0.01.

FIG. 1 Spleen IgM response to SRBC. The spleen IgM response is illustrated after pretreatment with MMA-SS. CP (25 mg/kg) was used as a positive control. Values represent the mean ± SE derived from six animals in each group. * p < 0.05 and ** p ≤ 0.01 vs. vehicle.

FIG. 2 The specific LALN IgM response to SRBC. The specific LALN IgM response/10⁶ cells to SRBC is illustrated after pretreatment with (A) total, (B) soluble and (C) insoluble MMA-SS. Values represent the mean ± SE derived from six animals in each group. CP (12.5 mg/kg) was used as a positive control. * p ≤ 0.05 and ** p ≤ 0.01 vs. vehicle.

FIG. 3 The total LALN IgM response to SRBC. The LALN IgM response to SRBC after pretreatment with (A) total, (B) soluble and (C) insoluble MMA-SS is illustrated. Values represent the mean ± SE derived from six animals in each group. CP (12.5 mg/kg) was used as a positive control. * p ≤ 0.05 and ** p ≤ 0.01 vs. vehicle.

FIG. 4 LALN cell counts after MMA-SS exposure. Cell counts of LALN from B6C3F1 mice after pretreatment with soluble MMA-SS and immunization with SRBC are depicted. Values represent the mean ± SE derived from six animals in each group. * p ≤ 0.05 and ** p ≤ 0.01 vs. vehicle.

TABLE 3 Flow cytometric analysis of the LALN cell populations

Soluble MMA-SS (mg/kg)	Cells/ml (×10^6)		CD3+	B220+	CD4+	CD8+
0	4.35 ± 0.31	% Lymphocyte Population	66.74 ± 2.56	24.39 ± 1.59	49.60 ± 1.67	15.80 ± 1.83
n = 9		Absolute # (cells ×10^6)	0.30 ± 0.03	0.10 ± 0.01	0.23 ± 0.02	0.07 ± 0.01
20	13.92 ± 1.65**	% Lymphocyte Population	68.63 ± 1.75	28.93 ± 1.75	48.92 ± 1.48	15.80 ± 1.80
n = 7		Absolute # (cells ×10^6)	1.35 ± 0.14**	0.58 ± 0.38**	0.98 ± 0.68**	0.32 ± 0.04**

Values represent the mean ± SE from the LALN of MMA-SS or vehicle treated mice.

**Significantly different from vehicle controls p ≤ 0.01.