Table 3 Functional immunotoxicity studies (T-cell Dependent Antibody Response (TDAR), T-cell Independent Antibody Response (TIAR) studies, host infection studies and lymphoproliferative response) with PFASs in rodents (see also Results, Repeated dose toxicity and immunotoxicity studies in animals section)
From: Consideration of pathways for immunotoxicity of per- and polyfluoroalkyl substances (PFAS)
PFASs | Species, strain, sex, and group size | Dose, exposure duration, and exposure route | Experimental design and study protocol | Response and effects observed | Reference |
|---|---|---|---|---|---|
PFOA | Mouse (C57BL/6, 4-6 M per group) | 0 and 24 mg/kg bw/day for 10 days (diet) | TDAR study. Immunization to HRBC (i.v. injection with 200 μL of 5-10 × 107 HRBC/mL in EBSS) on day 5, 6 days before sacrifice. One group continued PFOA treatment for 6 days after immunization (i.e. total of 16 days exposure; others normal chow). Measurement of HRBC-specific IgM levels with PFC assay and ELISA. | TDAR study. ↓ plaque formation by HRBC-specific IgM and IgG, ↓ HRBC-specific IgM and IgGs in serum, both at 24 mg/kg bw/day. | [69] |
PFOS, PFOA | Mouse (Balb/c, 5 F per group) | 0 and 20 mg/kg bw/day for 21 days (oral gavage) | TDAR study. Immunization to OVA twice (2 weeks apart, i.p. injections of 0.1 mg/kg with 100 μL OVA) on days 8 and 15. Second injection was 7 days before sacrifice. Measurement of OVA-specific IgM levels with ELISA. Other observations: Splenic and thymic cellularity. | TDAR study. ↓ OVA-specific IgM at 20 mg/kg bw/day PFOA and 20 mg/kg bw/day PFOS respectively. | [64] |
PFOA | Mouse (Crl:CD-1(ICR)BR, 20 M per group) Rats, (Crl:CD(SD)IGS BR, 10 M per group) | 0.3, 1, 10, and 30 mg/kg bw/day for 29 days (oral gavage, mouse and rat) | TDAR study. Immunization to SRBC (i.v. injection with 0.5 mL of 4 × 108 SRBC/mL (rat) or 0.2 ml of 1 × 109 SRBC/mL (mouse)) on day 23 (rat) or 24 (mouse), seven (rats) or six (mouse) days before sacrifice. Measurement of SRBC-specific IgM levels with ELISA. Other observations. Body weight, organ weight and histopathology, hematology, clinical chemistry, corticosterone measurement, spleen and thymus cellularity. | Mouse: TDAR study. ↓ SRBC-specific IgM ≥ 10 mg/kg bw/day. Other observations. ↑ liver weight and liver focal necrosis ≥1 mg/kg bw/day. ↓ body weight, spleen and thymus weight, atrophy of lymphoid tissue, eosinophils, total number of thymocytes and splenocytes ↑ neutrophils and monocytes, corticosterone serum levels) ≥ 10 mg/kg bw/day. ↓ lymphocytes at 30 mg/kg bw/day. Rat: TDAR study. PFOA had no effect on production of anti-SRBC IgM. Other observations. ↑ liver weight, minimal focal liver necrosis and corticosterone serum levels ≥10 mg/kg bw/day. | [65] |
PFOA | Mouse (C57BL/6 N, 8 F per group) | 0 and 30 mg/kg for 15 days (constant group) or 10 days (recovery group); dose response study I with 0, 3.75, 7.5, 17, 30 mg/kg bw/day for 15 days (drinking water); and dose response study II 0, 0.94, 1.88, 3.75, 7.5 mg/kg bw/day for 15 days (drinking water) | TDAR study. Immunization to SRBC once (i.v. injection with 4.0 × 107 SRBC in 0.2 mL saline), on day 11, or immunization to SRBC twice (2 weeks apart, i.v. injection with 4.0 × 107 SRBC in 0.2 mL saline), on day 11 and day 25. Animals were sacrificed 5 days after. Measurement of SRBC-specific IgM and IgG levels with ELISA. DTH study. On day 11, animals were sensitized with a subcutaneous injection of BSA-CFA (0.05 mL of 2 mg/mL BSA-CFA). At day 18, animals were challenged with an injection of 0.05 mL of heat-aggregated BSA into the right footpad. Footpad thickness was measured 24 h post-challenge. Other observations. Body weight, lymphoid organ weights (spleen, thymus). | [66] | |
PFOA | Mouse (adrenalectomized or sham-operated C57BL/6 N, 6 F per group) | 0, 3.75, 7.5, or 15 mg /kg bw for 10 days (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 7.5 × 107 SRBC in 0.2 mL saline) on day 11, 5 days before sacrifice. Measurement of SRBC-specific IgM levels with ELISA. Other observations. Corticosterone serum levels. | TDAR study. ↓ IgM ≥ 7.5 mg/kg bw/day in adx and ↓ IgM at 15 mg/kg bw/day in sham mice. Other observations. Increase in corticosterone only at 15 mg/kg bw/day in sham mice. Hence, suppression of SRBC-specific IgM was not the result of corticosterone production. | [67] |
PFOA | Mouse (PPARα-KO; B6.129S4-Ppartm1GonzN12 and WT C57BL/6-Tac, 4-6 F per group) TIDAR: mouse (C57BL/6 N WT, 8 F per group) | PPARα-KO mice compared to WT, exposed to 0, 7.5 or 30 mg/kg bw/day for 15 days (TDAR) or 0, 0.94, 1.88, 3.75, and 7.5 mg/kg bw/day for 15 days (TIDAR) (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 7.5 × 107 SRBC in 0.2 mL saline) on day 11, 5 days before sacrifice. Measurement of SRBC-specific IgM levels with ELISA. TIDAR study. Immunization to DNP-LPS (i.v. injection with 1 μg DNP-LPS in 0.2 mL saline) on day 11, seven days before sacrifice. Measurement of DNP-LPS-specific IgM levels with ELISA. Other observations. Body weights, lymphoid organ weights, splenic lymphocyte phenotypes (the latter in non-immunized PFOA-treated mice). | TDAR study. ↓ SRBC-specific IgM at 30 mg/kg bw/day in both PPARα KO (no decline in bw, spleen-, or thymus weight observed) and WT mice (decline in bw, spleen- and thymus weight). TIDAR study. ↓ DNP-LPS-specific IgM ≥ 1.88 mg/kg bw/day. | [116] |
PFOA | Mouse (B6C3F1, 12-16 F per group) | 0, 1.88 and 7.5 mg/kg bw/day for 28 days (drinking water) | TDAR study. Immunization to KLH (i.p. injection with 300 mg KLH/mice in a total volume of 0.5 mL) on day 24, 5 days before sacrifice. Measurement of KLH-specific IgM levels with ELISA. Other observations. Body weight, serum cytokines, serum corticosterone. | TDAR study. ↓ KLH-specific IgM ≥ 1.88 mg/kg bw/day. Other observations. Serum corticosterone was not significantly correlated with TDAR or measured cytokines. At 5 mg/kg bw/day, ↓ Th2, mixed response for Th1 cytokines (overall favoring a Th1 balance). At both treated groups, ↓ pro-inflammatory cytokines. | [63] |
PFOS | Mouse (B6C3F1, 5 per sex/group for TDAR study, 10 F per group for TIDAR study) | 0, 0.166, 1.66, 3.31, 16.6, 33.1, and 166 μg/kg bw/day for 28 days (oral gavage) (TDAR study) 0 and 334 μg/kg bw/day for 21 days (oral) (TIDAR study) | TDAR study. Immunization to SRBC (i.p. injection, 0.1 mL of 25% SRBC in PBS) on day 23, 5 days before sacrifice. Measurement of SRBC-specific IgM with PFC assay. TIDAR study. Immunization to TNP-LPS (i.v. injection in tail vein, 100 μL of 1 μg TNP-LPS/μL) on day 14, 7 days before sacrifice. Measurement of TNP-LPS-specific IgM with ELISA. Other observations. Splenic and thymic CD4/CD8 subpopulations. | TDAR study. ↓ SRBC-specific IgM ≥ 1.66 μg/kg bw/day in M and ≥ 16.6 μg/kg bw/day in F. TIDAR study. ↓ TNP-specific IgM at 334 μg/kg bw/day in F. Other observations. Alteration of splenic (but not thymic) CD4/CD8 T-cells ≥3.31 μg/kg bw/day in M, and alteration of splenic and thymic CD4/CD8 T-cells ≥3.31 μg/kg bw/day in F. | [70] |
PFOS | Mouse (C57BL/6, 12 M per group) | 0, 5, 20 and 40 mg/kg bw/day for 7 days (oral gavage) | TDAR study. Immunization to SRBC (i.p. injection with 0.1 mL of a 25% SRBC suspension in PBS) on day three, 5 days before sacrifice. Measurement of SRBC-specific IgM with PFC assay. NK cell activity. Splenocytes and Yac-1 cells were prepared in the ratio 10:1. Then, the amount of LDH released from lysed Yac-1 cells was determined to observe NK cell activity. Lymphoproliferative response. Isolated splenocytes were exposed to either 10 μg/mL ConA or LPS. After that, proliferation was determined using the MTT assay. Other observations. Body weight, organ weights (liver, kidney, spleen, and thymus), thymus and spleen cellularity, serum corticosterone, thymic and splenic CD4/CD8 subpopulations. | TDAR study. ↓ SRBC-specific IgM ≥ 5 mg/kg bw/day. NK cell activity. ↓ NK cell activity ≥20 mg/kg bw/day Lymphoproliferative response. ↓ splenic leukocyte proliferation in response to ConA and LPS ≥ 5 mg/kg bw/day. Other observations. ↓ splenic and thymic cellularity, ↑ liver weight ≥ 5 mg/kg bw/day. ↓ body weight, thymus and spleen weight, ↓ splenic and thymic lymphocyte subpopulations, ↑ serum corticosterone ≥20 mg/kg bw/day. Severe impairment of terminal body weight and food intake ≥20 mg/kg bw/day. Mean terminal body weight decreased with approximately 15 and 25% at 20 and 40 mg/kg bw/day respectively. | [71] |
PFOS | Mouse (C57BL/6, 10 M per group) | 0, 0.008, 0.08, 0.42, 0.83, and 2.1 mg/kg bw/day for 60 days (oral gavage) | TDAR study. Immunization to SRBC (i.p. injection with 0.1 mL of a 25% SRBC suspension in PBS) on day 57, 4 days before sacrifice. Measurement of SRBC-specific IgM with PFC assay. NK cell activity. Splenocytes and Yac-1 cells were prepared in the ratio 10:1. Then, the amount of LDH released from lysed Yac-1 cells was determined to observe NK cell activity. Lymphoproliferative response. Isolated splenocytes were exposed to either 10 μg/mL ConA or LPS. After that, proliferation was determined using the MTT assay. Other observations. Body weight, organ weights (liver, spleen, and thymus), thymus and spleen cellularity, serum corticosterone, thymic and splenic CD4/CD8 subpopulations. | TDAR study. ↓ SRBC-specific IgM ≥ 0.08 mg/kg bw/day. NK cell activity. ↓ NK cell activity ≥0.83 mg/kg bw/day. Lymphoproliferative response. ↓ splenic leukocyte proliferation in response to ConA and LPS ≥ 0.83 mg/kg bw/day. Other observations. ↓ body weight, spleen and thymus weights, spleen and thymus cellularity, splenic and thymic T-cell subpopulations ≥0.42 mg/kg bw/day. ↑ serum corticosterone level ≥ 0.83 mg/kg bw/day. | [72] |
PFOS | Mouse (C57BL/6, 6 M per group) | 0, 0.0083, 0.017, 0.083, 0.42 and 0.83 mg/kg bw/day for 60 days (oral gavage) | TDAR and DTH study. Immunization to SRBC (i.v. injection with 4.0 × 107 SRBC in 0.2 mL saline) on day 54 in 12 animals per group, 7 days before sacrifice. On day 60, 6 animals per group received a SRBC booster immunization (footpad injection with 4.0 × 107 SRBC in 0.2 mL saline) for assessment of a DTH response (footpad swelling) and different immunoglobulin determinations (IgGs, IgE). Measurement of SRBC-specific immunoglobulins with ELISA. Other observations. Body weight, organ weights (liver, spleen, and thymus), serum corticosterone, measurement of cytokines. | TDAR study. ↓ SRBC-specific IgM ≥ 0.083 mg/kg bw/day. DTH study. No increased footpad swelling was observed in treated groups compared to the control group. Other observations. ↓ bw change, food consumption, spleen and thymus weights ≥0.833 mg/kg bw/day. ↑ SRBC-specific IgGs and SRBC-specific IgE at 0.83 mg/kg bw/day. ↑ IL-4 ≥ 0.083 mg/kg bw/day, ↑ IL-10 at 0.83 mg/kg bw/day, ↓ IL-2 and INF-γ at 0.83 mg/kg bw/day. | [73] |
PFOS | Mouse (B6C3F1, 10-12 dams per group) | 0.1, 1, and 5 mg/kg bw/day on GD 1-17 (oral gavage) | TDAR study. Immunization to SRBC (i.v. injection with 7.5 × 107 SRBC in 0.2 mL saline) in eight-week-old F1 pups (6 sex/dose), 4 days before sacrifice. Measurement of SRBC-specific IgM with PFC assay. NK cell activity. Splenocytes and Yac-1 cells were prepared in different ratios (200:1, 100:1, 50:1, 25:1, 12.5:1, 6.25:1). Then, lysis was determined by lysing 51Cr-labeled Yac-1 cells with 0.1% Triton X in complete media. Other observations. Body weight, organ weight (liver, thymus, spleen, uterus), spleen and thymus cellularity, splenic and thymic CD4/CD8 subpopulations, nitrite production by peritoneal macrophages. | TDAR study. ↓ of SRBC-specific IgM in M at 5 mg/kg bw/day at week 8. NK cell activity. ↓ NK cell activity in M ≥ 1 mg/kg bw/day and in F at 5 mg/kg bw/day at week 8. Other observations. At week 4, ↑ liver weight in M at 5 mg/kg bw/day. ↓ CD3+ and CD4+ thymocytes in M at 5 mg/kg bw/day. In maternal animals ↓ CD4:CD8 ratio at 5 mg/kg bw/day. | [74] |
PFOS | Rat (SD, 10-15 per sex/group) | 0.14, 1.33, 3.21, 6.34 (M) and 0.15, 1.43, 3.73, 7.58 (F) mg/kg bw/day for 28 days (diet) | TDAR and DTH study. Immunization to KLH twice (i.p. injection with 1 mg KLH) on day 14 and day 21, 14 and 7 days before sacrifice. On day 28, rats were injected with 2 mg heat-inactivated KLH or saline in the left and right footpad respectively, to measure swelling after 24 h. Right after measuring footpad swelling, blood serum was sampled for measuring KLH-specific IgG with ELISA. Other observations. Body weight, organ weights (liver, thymus, spleen), organ histopathology (liver, thymus, spleen, mesenteric lymph nodes), total serum immunoglobulin (IgM, IgA, IgG, unchallenged), peripheral blood lymphocyte phenotyping, splenocyte proliferation. | TDAR study. ↑ KLH-specific IgG in M at the highest dose in M, but not in F. DTH study. There was no statistically significant change in footpad swelling. Other observations. ↓ body weight and ↑ liver weight at the two highest dose groups (M, F), and ↓ spleen (M) and thymus (M, F) weight at the highest dose. ↑ total IgM (unchallenged) in F at the highest dose. No effect on peripheral blood lymphocyte phenotype, or splenic leukocyte proliferation in response to ConA and LPS. Challenging regimen and timepoint of measuring KLH-specific IgG differs from other TDAR studies. | [75] |
PFOS | Mouse (B6C3F1, 5 M per group) | 0 and 250 μg/kg bw/day for 28 days (diet) | TDAR study. Immunization to SRBC (i.p. injection with 0.1 mL of a 1:10 SRBC suspension in PBS) on day 23, 5 days before sacrifice. Measurement of SRBC-specific IgM and IgG with ELISA and IgM with PFC assay. TIDAR study. Immunization TNP-LPS (i.v. injection with 0.1 mL of 100 μl/mL TNP-LPS in 0.9% NaCl) on day 23, 5 days before sacrifice. Measurement of TNP-LPS-specific IgM with ELISA. Other observations. Organ and tissue weights (liver, epididymal fat, spleen, and thymus), serum corticosterone, immunophenotyping of the thymus and the spleen. | TDAR, TIDAR, and other observations. No change in the TDAR or TIDAR at 250 μg/kg bw/day compared to the control group. Serum levels of SRBC-specific IgM and IgG or levels of TNP-LPS-specific IgM were not altered by PFOS treatment. ↑ weight of the liver at 250 μg/kg bw/day. Cellular compositions of the thymus and spleen were not altered. No effect on corticosterone levels observed compared to the control group. Study was performed with one low dose and had small group sizes. | [78] |
HFPO-DA | Mouse (C57BL/6, 6 per sex/group) | 0, 1, 10, or 100 mg/kg bw/day for 28 days (oral gavage) | TDAR study. Immunization to SRBC (i.v. injection with 4 × 107 SRBC in 0.2 mL saline) on day 24, 5 days before sacrifice. Measurement of IgM by ELISA. Other observations. Body weight, organ weights (liver, thymus, spleen), immunophenotyping of spleen. | TDAR study. ↓ SRBC-specific IgM in F, but not in M, at 100 mg/kg bw/day. Other observations. ↑ CD8+ and CD4−/CD8− T cells in M at 100 mg/kg bw/day. ↓ relative spleen weight in F at 100 mg/kg bw/day. | [76] |
PFMOAA | Mouse (C57BL/6, 4-6 per sex/group) | 0, 0.00025, 0..025 and 2.5 mg/kg bw/day for 30 days (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 4 × 107 SRBC in 0.2 mL saline) on day 26, 5 days before sacrifice. Measurement of IgM with ELISA. Other observations. Body weight, organ weights (liver, thymus, spleen), immunophenotyping of thymus and spleen. | TDAR study. No statistical differences were detected in the TDAR in M or F animals given PFMOAA compared to the control group. Other observations. No statistically significant effect was observed on body weight, lymphoid organ weight, and thymus and spleen immunophenotyping, up to the highest dose tested. | [79] |
PFMOPrA | Mouse (C57BL/6, 4-6 per sex/group) | 0, 0.5, 5, and 50 mg/kg bw/day for 30 days (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 4 × 107 SRBC in 0.2 mL saline) on day 26, 5 days before sacrifice. Measurement of IgM with ELISA. NK cell activity. YAK-1 cells were prepared 5 days before the NK cell assay. Spleens were processed and lymphocytes were isolated. Lymphocyte and YAK-1 cells were prepared in three ratios (5:1, 10:1, and 30:1). After that, the percent specific lysis was determined by flow analysis. Other observations. Body weight, organ weights (liver, thymus, spleen), immunophenotyping of thymus and spleen. | TDAR study. No statistical differences were detected in the TDAR in M or F animals given PFMOPrA compared to the control groups. NK cell activity. There was no statistically significant change in NK cell activity. Other observations. ↓ in spleen weight in F at 0.5 and 50 mg/kg bw/day, ↑ in spleen weight in F at 5 mg/kg bw/day. Dosing regimen of M animals was increased (2-fold) after week one of the experiment. | |
PFMOBA | Mouse (C57BL/6, 4-6 per sex/group) | 0, 0.5, 5, and 50 mg/kg bw/day for 30 days (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 4 × 107 SRBC in 0.2 mL saline) on day 26, 5 days before sacrifice. Measurement of IgM with ELISA. NK cell activity. YAK-1 cells were prepared 5 days before the NK cell assay. Spleens were processed and lymphocytes were isolated. Target cells (500 μL) were added to effector cells in three E:T ratios (5:1, 10:1, and 30:1). After that, the percent specific lysis was determined by flow analysis. Other observations. Body weight, organ weights (liver, thymus, spleen), immunophenotyping of thymus and spleen, natural killer cell activity. | TDAR study. No statistical differences were detected in the TDAR in M or F animals given PFMOBA compared to the control group. NK cell activity. There was no statistically significant change in NK cell activity. Other observations. ↑ B cells and NK cells in the spleen in M at all doses compared to the control group, and ↓ B cells and NK cells in the spleen at 50 mg/kg bw/day in F compared to the control group. | |
PFOA | Mouse (C57BL/6, 4-6 per sex/group) | 0, and 7.5 mg/kg bw/day for 30 days (drinking water) | TDAR study. Immunization to SRBC (i.v. injection with 4 × 107 SRBC in 0.2 mL saline) on day 26, 5 days before sacrifice. Measurement of IgM with ELISA. Other observations. Body weight, organ weights (liver, thymus, spleen), immunophenotyping of thymus and spleen. | TDAR study. No statistical differences were detected in the TDAR in M or F animals given PFOA compared to the control group. Other observations. ↓ relative spleen weight at 7.5 mg/kg bw/day in F. PFOA, serving as the positive control, was also negative in the TDAR study. | |
AFFF formulation (containing C5-C10 PFSA, PFOA, Cl-PFOS or precursors thereof) | Mouse (C57BL/6, 6 per sex/group) | AFFF formulation (based on 0, 1.88, 3.75, 7.5, or 10 mg/kg bw/day PFOS + PFOA measured in the formulation) for 10 days followed by 6 days of depuration (oral gavage) | TDAR study. Immunization to SRBC (i.v. injection with 7.5 × 107 SRBC in 0.2 mL saline) on day 11, 5 days before sacrifice. Measurement of SRBC-specific IgM levels with ELISA. Other observations. Body weight, liver weight, lymphoid organ weights, spleen cellularity, splenic lymphocyte subpopulations. | TDAR study. ↓ SRBC-specific IgM in F and M ≥ 7.5 mg/kg bw/day. Other observations. ↓ rel. Spleen weight in M at 10 mg/kg bw/day and ↓ body weight, rel. Thymus weight in F and M ≥ 7.5 mg/kg bw/day. ↑ liver weight in all treated dose groups in M and F compared to the control groups. | [77] |
PFOA | Mouse (C57BL/6, 6 per sex/group) | 0 and 7.5 mg/kg bw/day PFOA) for 10 days followed by 6 days of depuration (oral gavage) | TDAR study. Immunization to SRBC (i.v. injection with 7.5 × 107 SRBC in 0.2 mL saline) on day 11, 5 days before sacrifice. Measurement of SRBC-specific IgM levels with ELISA. | TDAR study. ↓ SRBC-specific IgM in F and M at 7.5 mg/kg bw/day. | |
PFDA | Mouse (B6C3F1/N, 8 F) and rat (SD, 8 F) | Rats: 0, 0.125, 0.25, 0.5, 1, and 2 mg/kg bw/day for 28 days (oral gavage) Mice: once each week (days 1, 8, 15, and 22) at doses of 0, 0.3125, 0.625, 1.25, 2.5, and 5 mg/kg bw/week (oral gavage) | TDAR study. Immunization to SRBC and KLH (i.v. injection with 2 mg KLH and an unknown quantity of SRBC respectively) on day 23 (in rat and mouse), and measurement of anti-SRBC and anti-KLH with ELISA. In a separate assay, immunization to SRBC on day 25 and measurement of spleen IgM with APC response. NK cell activity. Splenocytes and 51Cr-labelled YAC-1 cells were prepared in different ratios (200:1, 100:1, 50:1, 25:1, 12.5:1, 6.25:1). Then, 100 μL supernatant was counted using a γ-counter. DTH study. On days 21 and 29, animals were challenged with a subcutaneous injection of C. albicans ((2 × 107 organisms for rats, 1 × 107 for mice) in the right footpad. Footpad thickness was measured right before the second challenge, and 24 h post-challenge. Mononuclear phagocyte system (MPS) activity. Uptake and vascular clearance of51Cr-labelled SRBC by fixed macrophages in the liver, spleen, thymus, lung and kidney. Intravenous injection with 51Cr-labelled SRBC on day 29. SRBC serum half-life and relative organ uptake was determined using a γ-counter 30-60 min. Post-injection. Host resistance to infection study. Mice (treated for 28 days as described above) were infected intranasally with Influenza A/Hong Kong/8/86 (H3N2) virus at three challenge levels (1:2420, 1:440, and 1:80 dilutions). Mice were observed twice daily for 21d for changes in appearance, locomotion, and respiration. Other observations. Body weight, organ histopathology, total and differential white blood cell counts, spleen cell immunophenotyping, bone marrow DNA synthesis, colony formation, and differentials. | TDAR study (mouse and rat). No PFDA exposure-related effects were observed on the AFC response to SRBC in rats or mice, or in the serum IgM levels to SRBC or KLH in rats. Host resistance to infection (mouse). Treatment with PFDA did not decrease survival compared to the control during the 21 day post-challenge observation period. DTH (mouse and rat). No increased footpad swelling was observed in treated groups compared to the control group. MPS activity (rat). Altered functional activity of mononuclear phagocytic system in liver and thymus ≥0.25 mg/kg bw/day. Other observations (mouse). ↓ spleen weight, splenic atrophy (20%), ↓ total spleen cells, Ig + and NK+ cells at 5.0 mg/kg bw/week PFDA, and ↓ CD3+, CD4+, CD8+, and Mac3+ cells in the spleen ≥1.25 mg/kg bw/week PFDA. Other observations (rat). No change from controls on lymphoid organ weights, leukocyte subpopulations, and bone marrow cellularity. | [82] |
PFHxS | Rat (HanTac: WH, dams, 8 or 20 litters per group in two separate experiments) | Dams were exposed to 0, 25, or 45 mg/kg bw/day a-nd 0, 0.5, 5 and 25 mg/kg bw/day PFHxS in two separate experiments during GD7-PND22 (oral gavage) | TDAR study. Immunization to KLH in weaned offspring twice (14 days apart, 200 μL of 1.5 mg/ml KLH via i.p. injection). At PND28 and PND 37 in experiment 1 and at PND34 and PND43 in experiment 2. Measurement of KLH-specific IgM and IgG with ELISA. DTH study. The day before sacrifice, animals were challenged intradermally with an injection of 20 μL of 5 mg/ml KLH or 20 μL saline in the left and right ear respectively. Right after sacrifice, the thickness of the ear was measured and weighted. Other observations. Lymphoid organ weights. | TDAR study. No effects on IgM and IgG responses up to the highest dose tested compared to the control group. DHT study. No increased ear swelling was observed in treated groups compared to the control group. Other observations. No effects on lymphoid organs in M or F at any dose apart from ↓ in lymph node wt in M at PND 16 in 25 and 45 mg/kg bw/day dose groups in experiment 1. Challenging regimen and timepoint of measuring KLH-specific IgM and IgG differs from other TDAR studies. Also the positive control cyclophosphamide was negative. | [80] |
PFOS | Mouse (C57BL/6, sex not specified, 4 per group) | 0 and 2 mg/kg bw/day for 18 days (oral gavage) | Host resistance to infection study. Challenge with mouse Citrobacter rodentium bacterium strain DBS100 (1010 cfu) in 200 μL PBS at day 7 via oral gavage. PFOS exposure was continued until the end of the experiment. Intestinal lamina propria lymphocytes were harvested during exposure and infection. | Host resistance to infection study. At 2 mg/kg bw/day, PFOS inhibited the outgrowth of the pathogen (↑ of IL-22 from ILC3 cells). In the later phase ↑ bacterial counts and ↑ of inflammatory cytokines, (↑ of IL-22 and IL-17 from ILC3 cells, ↑ IFN-γ from CD3− cells, ↑ of IL-22 and IL-17 from Th17 cells), reduced mucus production, dysbiosis, ↑ levels of E.coli. | [83] |
PFOS | Mouse (C57BL/6, 4-5 per sex/group (exp. 1) and 8-10 per sex/group (exp. 2)) | 0 and 1.5 μg/kg bw/day for 28 days (oral gavage) | Host resistance to infection study. Experiment 1: Challenge with mouse influenza virus strain A/WSN/33 (H1N1) intranasally (1e6 pfu/mouse) at day 28. Body weights were monitored. After 11 days, BALF was collected from the lungs, and blood, lungs, liver and spleen were collected. Experiment 2: Challenge with mouse influenza virus strains A/WSn/33(H1N1)(WSN-OVA1) and A/WSN/33(H1N1)(WSN-OVA11) intranasally (2e4 pfu/mouse) at day 28. Body weights and tissue collections were as described above. | Host resistance to infection study. Experiment 1. No effect on virus-induced weight loss, on the number of inflammatory cells, T cells, and granulocytes in the lung. ↓ CD4+ and ↑ CD8+ T cells in BALF and ↑ CD4+CD44Hi in the lung at 1.5 μg/kg bw/day. Experiment 2. No effect on virus-induced weight loss, no effect on inflammatory cells in BALF, no difference in the percentage of antigen-specific CD4+ or CD8+ T cells in the spleen. ↑ number of antigen-specific CD4+ T cells in the spleen at 1.5 μg/kg bw/day. Study was performed with one low dose and had small group sizes. | [81] |
PFNA | Mouse (C57BL/6, 5 per sex/group). | 0 or 0.46 mg/kg bw once (i.p. injection) | Lymphoproliferative response. Immunization to LPS on day 14 (i.p. injection with 1 mg/kg LPS or saline). 1.5 hours after administration of LPS, blood was collected to quantify the TNFα concentration by ELISA. Other observations. Spleen, thymus, kidney and liver were collected on day 14. Splenocyte and thymocyte immunophenotyping was performed by flow cytometry analysis. | Lymphoproliferative response. ↑ TNFα Other observations. Spleen atrophy, ↓ spleen weight, spleen leukocyte count, spleen red blood cell count, ↑ CD4+, CD8+ in the spleen, ↓ CD4+/CD8+ cells in the thymus, ↑ CD4+, CD8+, CD4−/CD8− cells in the thymus. ↓ CD14+ cells and CD19+ cells in the spleen. Animals were exposed once via i.p. injection. | [97] |
PFNA | Mouse (C57BL/6 J, 5 per sex/group). | 0 or 0.46 mg/kg bw once (i.p. injection) | Lymphoproliferative response. Immunization to LPS on day 28 (i.p. injection with 1 mg/kg LPS or saline). 1.5 hours after administration of LPS, blood was collected to quantify the TNFα concentration by ELISA. Other observations: Spleen, thymus and liver were collected on day 28. Splenocyte and thymocyte immunophenotyping was performed by flow cytometry analysis. | Lymphoproliferative response. ↑ TNFα Other observations. ↑ CD14+ cells and ↓ CD19+ cells in the spleen. Spleen and thymus atrophy, ↓ spleen and thymus weights, ↑ CD4+, CD8+ in the spleen, ↓ CD4+/CD8+ cells in the thymus. Animals were exposed once via i.p. injection. | [96] |