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"""
Idea:
- take an allele where MS vs. no-MS trained predictors are very different. One
possiblility is DLA-88*501:01 but human would be better
- generate synethetic multi-allele MS by combining single-allele MS for differnet
alleles, including the selected allele
- train ligandome predictor based on the no-ms pan-allele models on theis
synthetic dataset
- see if the pan-allele predictor learns the "correct" motif for the selected
allele, i.e. updates to become more similar to the with-ms pan allele predictor.
"""
import logging
logging.getLogger('tensorflow').disabled = True
logging.getLogger('matplotlib').disabled = True
import pandas
import argparse
import sys
import numpy
from random import shuffle
from mhcflurry import Class1AffinityPredictor, Class1NeuralNetwork
from mhcflurry.class1_ligandome_predictor import Class1LigandomePredictor
from mhcflurry.common import random_peptides, positional_frequency_matrix
from mhcflurry.testing_utils import cleanup, startup
from mhcflurry.amino_acid import COMMON_AMINO_ACIDS
from mhcflurry.custom_loss import MultiallelicMassSpecLoss
COMMON_AMINO_ACIDS = sorted(COMMON_AMINO_ACIDS)
PAN_ALLELE_PREDICTOR_NO_MASS_SPEC = None
PAN_ALLELE_MOTIFS_WITH_MASS_SPEC_DF = None
PAN_ALLELE_MOTIFS_NO_MASS_SPEC_DF = None
def setup():
global PAN_ALLELE_PREDICTOR_NO_MASS_SPEC
global PAN_ALLELE_MOTIFS_WITH_MASS_SPEC_DF
global PAN_ALLELE_MOTIFS_NO_MASS_SPEC_DF
startup()
PAN_ALLELE_PREDICTOR_NO_MASS_SPEC = Class1AffinityPredictor.load(
get_path("models_class1_pan", "models.no_mass_spec"),
optimization_level=0,
max_models=1)
PAN_ALLELE_MOTIFS_WITH_MASS_SPEC_DF = pandas.read_csv(
get_path(
"models_class1_pan",
"models.with_mass_spec/frequency_matrices.csv.bz2"))
PAN_ALLELE_MOTIFS_NO_MASS_SPEC_DF = pandas.read_csv(
get_path(
"models_class1_pan",
"models.no_mass_spec/frequency_matrices.csv.bz2"))
def teardown():
global PAN_ALLELE_PREDICTOR_NO_MASS_SPEC
global PAN_ALLELE_MOTIFS_WITH_MASS_SPEC_DF
global PAN_ALLELE_MOTIFS_NO_MASS_SPEC_DF
PAN_ALLELE_PREDICTOR_NO_MASS_SPEC = None
PAN_ALLELE_MOTIFS_WITH_MASS_SPEC_DF = None
PAN_ALLELE_MOTIFS_NO_MASS_SPEC_DF = None
cleanup()
def scramble_peptide(peptide):
lst = list(peptide)
shuffle(lst)
return "".join(lst)
def evaluate_loss(loss, y_true, y_pred):
import keras.backend as K
y_true = numpy.array(y_true)
y_pred = numpy.array(y_pred)
if y_pred.ndim == 1:
y_pred = y_pred.reshape((len(y_pred), 1))
if y_true.ndim == 1:
y_true = y_true.reshape((len(y_true), 1))
if K.backend() == "tensorflow":
session = K.get_session()
y_true_var = K.constant(y_true, name="y_true")
y_pred_var = K.constant(y_pred, name="y_pred")
result = loss(y_true_var, y_pred_var)
return result.eval(session=session)
elif K.backend() == "theano":
y_true_var = K.constant(y_true, name="y_true")
y_pred_var = K.constant(y_pred, name="y_pred")
result = loss(y_true_var, y_pred_var)
return result.eval()
else:
raise ValueError("Unsupported backend: %s" % K.backend())
print("delta", delta)
# Hit labels
y_true = [
1.0,
0.0,
1.0,
1.0,
0.0
]
y_true = numpy.array(y_true)
y_pred = [
[0.3, 0.7, 0.5],
[0.2, 0.4, 0.6],
[0.1, 0.5, 0.3],
]
y_pred = numpy.array(y_pred)
# reference implementation 1
def smooth_max(x, alpha):
x = numpy.array(x)
alpha = numpy.array([alpha])
return (x * numpy.exp(x * alpha)).sum() / (
numpy.exp(x * alpha)).sum()
contributions = []
for i in range(len(y_true)):
if y_true[i] == 1.0:
for j in range(len(y_true)):
if y_true[j] == 0.0:
tightest_i = max(y_pred[i])
contribution = sum(
max(0, y_pred[j, k] - tightest_i + delta)**2
for k in range(y_pred.shape[1])
)
contributions.append(contribution)
contributions = numpy.array(contributions)
# reference implementation 2: numpy
pos = numpy.array([
max(y_pred[i])
for i in range(len(y_pred))
if y_true[i] == 1.0
])
numpy.maximum(0, neg.reshape((-1, 1)) - pos + delta)**2).sum() / (
len(pos) * len(neg))
yield numpy.testing.assert_almost_equal, expected1, expected2, 4
computed = evaluate_loss(
MultiallelicMassSpecLoss(delta=delta).loss,
y_true,
y_pred.reshape(y_pred.shape + (1,)))
yield numpy.testing.assert_almost_equal, computed, expected1, 4
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AA_DIST = pandas.Series(
dict((line.split()[0], float(line.split()[1])) for line in """
A 0.071732
E 0.060102
N 0.034679
D 0.039601
T 0.055313
L 0.115337
V 0.070498
S 0.071882
Q 0.040436
F 0.050178
G 0.053176
C 0.005429
H 0.025487
I 0.056312
W 0.013593
K 0.057832
M 0.021079
Y 0.043372
R 0.060330
P 0.053632
""".strip().split("\n")))
print(AA_DIST)
def make_random_peptides(num_peptides_per_length=10000, lengths=[9]):
peptides = []
for length in lengths:
peptides.extend(
random_peptides
(num_peptides_per_length, length=length, distribution=AA_DIST))
return EncodableSequences.create(peptides)
def make_motif(allele, peptides, frac=0.01):
peptides = EncodableSequences.create(peptides)
predictions = PAN_ALLELE_PREDICTOR_NO_MASS_SPEC.predict(
peptides=peptides,
allele=allele,
)
random_predictions_df = pandas.DataFrame({"peptide": peptides.sequences})
random_predictions_df["prediction"] = predictions
random_predictions_df = random_predictions_df.sort_values(
"prediction", ascending=True)
top = random_predictions_df.iloc[:int(len(random_predictions_df) * frac)]
matrix = positional_frequency_matrix(top.peptide.values)
return matrix
ms_df = pandas.read_csv(
get_path("data_mass_spec_annotated", "annotated_ms.csv.bz2"))
ms_df = ms_df.loc[
(ms_df.mhc_class == "I") & (~ms_df.protein_ensembl.isnull())].copy()
sample_table = ms_df.drop_duplicates(
"sample_id").set_index("sample_id").loc[ms_df.sample_id.unique()]
grouped = ms_df.groupby("sample_id").nunique()
for col in sample_table.columns:
if (grouped[col] > 1).any():
del sample_table[col]
sample_table["alleles"] = sample_table.hla.str.split()
ms_df.sample_id == "RA957"
].drop_duplicates("peptide")[["peptide", "sample_id"]].reset_index(drop=True)
multi_train_hit_df["label"] = 1.0
multi_train_decoy_df = ms_df.loc[
(ms_df.sample_id == "CD165") &
(~ms_df.peptide.isin(multi_train_hit_df.peptide.unique()))
].drop_duplicates("peptide")[["peptide"]]
(multi_train_decoy_df["sample_id"],) = multi_train_hit_df.sample_id.unique()
multi_train_decoy_df["label"] = 0.0
multi_train_df = pandas.concat(
[multi_train_hit_df, multi_train_decoy_df], ignore_index=True)
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multi_train_df["is_affinity"] = False
multi_train_alleles = set()
for alleles in sample_table.loc[multi_train_df.sample_id.unique()].alleles:
multi_train_alleles.update(alleles)
multi_train_alleles = sorted(multi_train_alleles)
pan_train_df = pandas.read_csv(
get_path(
"models_class1_pan", "models.with_mass_spec/train_data.csv.bz2"))
pan_sub_train_df = pan_train_df.loc[
pan_train_df.allele.isin(multi_train_alleles),
["peptide", "allele", "measurement_inequality", "measurement_value"]
]
pan_sub_train_df["label"] = pan_sub_train_df["measurement_value"]
del pan_sub_train_df["measurement_value"]
pan_sub_train_df["is_affinity"] = True
pan_predictor = Class1AffinityPredictor.load(
get_path("models_class1_pan", "models.with_mass_spec"),
optimization_level=0,
max_models=1)
allele_encoding = MultipleAlleleEncoding(
experiment_names=multi_train_df.sample_id.values,
experiment_to_allele_list=sample_table.alleles.to_dict(),
max_alleles_per_experiment=sample_table.alleles.str.len().max(),
allele_to_sequence=pan_predictor.allele_to_sequence,
)
allele_encoding.append_alleles(pan_sub_train_df.allele.values)
allele_encoding = allele_encoding.compact()
combined_train_df = pandas.concat([multi_train_df, pan_sub_train_df])
ligandome_predictor = Class1LigandomePredictor(
pan_predictor,
pre_predictions = from_ic50(
ligandome_predictor.predict(
output="affinities",
peptides=combined_train_df.peptide.values,
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(model,) = pan_predictor.class1_pan_allele_models
expected_pre_predictions = from_ic50(
model.predict(
peptides=numpy.repeat(combined_train_df.peptide.values, len(alleles)),
allele_encoding=allele_encoding.allele_encoding,
)).reshape((-1, len(alleles)))[:,0]
assert_allclose(pre_predictions, expected_pre_predictions, rtol=1e-4)
motifs_history = []
random_peptides_encodable = make_random_peptides(10000, [9])
def update_motifs():
for allele in multi_train_alleles:
motif = make_motif(allele, random_peptides_encodable)
motifs_history.append((allele, motif))
print("Pre fitting:")
update_motifs()
print("Fitting...")
ligandome_predictor.fit(
peptides=combined_train_df.peptide.values,
labels=combined_train_df.label.values,
allele_encoding=allele_encoding,
affinities_mask=combined_train_df.is_affinity.values,
inequalities=combined_train_df.measurement_inequality.values,
progress_callback=update_motifs,
)
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import ipdb ; ipdb.set_trace()
def test_synthetic_allele_refinement_with_affinity_data(max_epochs=10):
refine_allele = "HLA-C*01:02"
alleles = [
"HLA-A*02:01", "HLA-B*27:01", "HLA-C*07:01",
"HLA-A*03:01", "HLA-B*15:01", refine_allele
]
peptides_per_allele = [
2000, 1000, 500,
1500, 1200, 800,
]
allele_to_peptides = dict(zip(alleles, peptides_per_allele))
length = 9
train_with_ms = pandas.read_csv(
get_path("data_curated", "curated_training_data.with_mass_spec.csv.bz2"))
train_no_ms = pandas.read_csv(get_path("data_curated",
"curated_training_data.no_mass_spec.csv.bz2"))
def filter_df(df):
df = df.loc[
(df.allele.isin(alleles)) &
(df.peptide.str.len() == length)
]
return df
train_with_ms = filter_df(train_with_ms)
train_no_ms = filter_df(train_no_ms)
ms_specific = train_with_ms.loc[
~train_with_ms.peptide.isin(train_no_ms.peptide)
]
train_peptides = []
train_true_alleles = []
for allele in alleles:
peptides = ms_specific.loc[ms_specific.allele == allele].peptide.sample(
n=allele_to_peptides[allele])
train_peptides.extend(peptides)
train_true_alleles.extend([allele] * len(peptides))
hits_df = pandas.DataFrame({"peptide": train_peptides})
hits_df["true_allele"] = train_true_alleles
hits_df["hit"] = 1.0
decoys_df = hits_df.copy()
decoys_df["peptide"] = decoys_df.peptide.map(scramble_peptide)
decoys_df["true_allele"] = ""
decoys_df["hit"] = 0.0
mms_train_df = pandas.concat([hits_df, decoys_df], ignore_index=True)
mms_train_df["label"] = mms_train_df.hit
mms_train_df["is_affinity"] = False
affinity_train_df = pandas.read_csv(
get_path(
"models_class1_pan", "models.with_mass_spec/train_data.csv.bz2"))
affinity_train_df = affinity_train_df.loc[
affinity_train_df.allele.isin(alleles),
["peptide", "allele", "measurement_inequality", "measurement_value"]]
affinity_train_df["label"] = affinity_train_df["measurement_value"]
del affinity_train_df["measurement_value"]
affinity_train_df["is_affinity"] = True
predictor = Class1LigandomePredictor(
PAN_ALLELE_PREDICTOR_NO_MASS_SPEC,
auxiliary_input_features=["gene"],
max_ensemble_size=1,
max_epochs=max_epochs,
learning_rate=0.0001,
patience=5,
min_delta=0.0,
random_negative_rate=1.0,
random_negative_constant=25)
mms_allele_encoding = MultipleAlleleEncoding(
experiment_names=["experiment1"] * len(mms_train_df),
experiment_to_allele_list={
"experiment1": alleles,
},
max_alleles_per_experiment=6,
allele_to_sequence=PAN_ALLELE_PREDICTOR_NO_MASS_SPEC.allele_to_sequence,
)
allele_encoding = copy.deepcopy(mms_allele_encoding)
allele_encoding.append_alleles(affinity_train_df.allele.values)
allele_encoding = allele_encoding.compact()
train_df = pandas.concat(
[mms_train_df, affinity_train_df], ignore_index=True, sort=False)
pre_predictions = from_ic50(
predictor.predict(
output="affinities_matrix",
peptides=mms_train_df.peptide.values,
alleles=mms_allele_encoding))
(model,) = PAN_ALLELE_PREDICTOR_NO_MASS_SPEC.class1_pan_allele_models
expected_pre_predictions = from_ic50(
model.predict(
peptides=numpy.repeat(mms_train_df.peptide.values, len(alleles)),
allele_encoding=mms_allele_encoding.allele_encoding,
)).reshape((-1, len(alleles)))
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mms_train_df["pre_max_prediction"] = pre_predictions.max(1)
pre_auc = roc_auc_score(mms_train_df.hit.values, mms_train_df.pre_max_prediction.values)
print("PRE_AUC", pre_auc)
assert_allclose(pre_predictions, expected_pre_predictions, rtol=1e-4)
motifs_history = []
random_peptides_encodable = make_random_peptides(10000, [9])
def update_motifs():
for allele in alleles:
motif = make_motif(allele, random_peptides_encodable)
motifs_history.append((allele, motif))
metric_rows = []
def progress():
(_, ligandome_prediction, affinities_predictions) = (
predictor.predict(
output="all",
peptides=mms_train_df.peptide.values,
alleles=mms_allele_encoding))
affinities_predictions = from_ic50(affinities_predictions)
for (kind, predictions) in [
("affinities", affinities_predictions),
("ligandome", ligandome_prediction)]:
mms_train_df["max_prediction"] = predictions.max(1)
mms_train_df["predicted_allele"] = pandas.Series(alleles).loc[
predictions.argmax(1).flatten()
].values
print(kind)
print(predictions)
mean_predictions_for_hit = mms_train_df.loc[
mms_train_df.hit == 1.0
].max_prediction.mean()
mean_predictions_for_decoy = mms_train_df.loc[
mms_train_df.hit == 0.0
].max_prediction.mean()
correct_allele_fraction = (
mms_train_df.loc[mms_train_df.hit == 1.0].predicted_allele ==
mms_train_df.loc[mms_train_df.hit == 1.0].true_allele
).mean()
auc = roc_auc_score(mms_train_df.hit.values, mms_train_df.max_prediction.values)
print(kind, "Mean prediction for hit", mean_predictions_for_hit)
print(kind, "Mean prediction for decoy", mean_predictions_for_decoy)
print(kind, "Correct predicted allele fraction", correct_allele_fraction)
print(kind, "AUC", auc)
metric_rows.append((
kind,
mean_predictions_for_hit,
mean_predictions_for_decoy,
correct_allele_fraction,
auc,
))
update_motifs()
return (ligandome_prediction, auc)
print("Pre fitting:")
progress()
update_motifs()
print("Fitting...")
predictor.fit(
peptides=train_df.peptide.values,
labels=train_df.label.values,
inequalities=train_df.measurement_inequality.values,
affinities_mask=train_df.is_affinity.values,
allele_encoding=allele_encoding,
progress_callback=progress,
)
(predictions, final_auc) = progress()
print("Final AUC", final_auc)
update_motifs()
motifs = pandas.DataFrame(
motifs_history,
columns=[
"allele",
"motif",
]
)
metrics = pandas.DataFrame(
metric_rows,
columns=[
"output",
"mean_predictions_for_hit",
"mean_predictions_for_decoy",
"correct_allele_fraction",
"auc"
])
return (predictor, predictions, metrics, motifs)
def Xtest_synthetic_allele_refinement(max_epochs=10):
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refine_allele = "HLA-C*01:02"
alleles = [
"HLA-A*02:01", "HLA-B*27:01", "HLA-C*07:01",
"HLA-A*03:01", "HLA-B*15:01", refine_allele
]
peptides_per_allele = [
2000, 1000, 500,
1500, 1200, 800,
]
allele_to_peptides = dict(zip(alleles, peptides_per_allele))
length = 9
train_with_ms = pandas.read_csv(
get_path("data_curated", "curated_training_data.with_mass_spec.csv.bz2"))
train_no_ms = pandas.read_csv(get_path("data_curated",
"curated_training_data.no_mass_spec.csv.bz2"))
def filter_df(df):
df = df.loc[
(df.allele.isin(alleles)) &
(df.peptide.str.len() == length)
]
return df
train_with_ms = filter_df(train_with_ms)
train_no_ms = filter_df(train_no_ms)
ms_specific = train_with_ms.loc[
~train_with_ms.peptide.isin(train_no_ms.peptide)
]
train_peptides = []
train_true_alleles = []
for allele in alleles:
peptides = ms_specific.loc[ms_specific.allele == allele].peptide.sample(
n=allele_to_peptides[allele])
train_peptides.extend(peptides)
train_true_alleles.extend([allele] * len(peptides))
hits_df = pandas.DataFrame({"peptide": train_peptides})
hits_df["true_allele"] = train_true_alleles
hits_df["hit"] = 1.0
decoys_df = hits_df.copy()
decoys_df["peptide"] = decoys_df.peptide.map(scramble_peptide)
decoys_df["true_allele"] = ""
decoys_df["hit"] = 0.0
train_df = pandas.concat([hits_df, decoys_df], ignore_index=True)
predictor = Class1LigandomePredictor(
PAN_ALLELE_PREDICTOR_NO_MASS_SPEC,
max_ensemble_size=1,
min_delta=0.0,
random_negative_rate=0.0,
random_negative_constant=0)
allele_encoding = MultipleAlleleEncoding(
experiment_names=["experiment1"] * len(train_df),
experiment_to_allele_list={
"experiment1": alleles,
},
max_alleles_per_experiment=6,
allele_to_sequence=PAN_ALLELE_PREDICTOR_NO_MASS_SPEC.allele_to_sequence,
).compact()
pre_predictions = from_ic50(
predictor.predict(
(model,) = PAN_ALLELE_PREDICTOR_NO_MASS_SPEC.class1_pan_allele_models
expected_pre_predictions = from_ic50(
model.predict(
peptides=numpy.repeat(train_df.peptide.values, len(alleles)),
allele_encoding=allele_encoding.allele_encoding,
)).reshape((-1, len(alleles)))
train_df["pre_max_prediction"] = pre_predictions.max(1)
pre_auc = roc_auc_score(train_df.hit.values, train_df.pre_max_prediction.values)
print("PRE_AUC", pre_auc)
assert_allclose(pre_predictions, expected_pre_predictions, rtol=1e-4)
motifs_history = []
random_peptides_encodable = make_random_peptides(10000, [9])
def update_motifs():
for allele in alleles:
motif = make_motif(allele, random_peptides_encodable)
motifs_history.append((allele, motif))
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707
alleles=allele_encoding))
affinities_predictions = from_ic50(affinities_predictions)
for (kind, predictions) in [
("affinities", affinities_predictions),
("ligandome", ligandome_prediction)]:
train_df["max_prediction"] = predictions.max(1)
train_df["predicted_allele"] = pandas.Series(alleles).loc[
predictions.argmax(1).flatten()
].values
print(kind)
print(predictions)
mean_predictions_for_hit = train_df.loc[
train_df.hit == 1.0
].max_prediction.mean()
mean_predictions_for_decoy = train_df.loc[
train_df.hit == 0.0
].max_prediction.mean()
correct_allele_fraction = (
train_df.loc[train_df.hit == 1.0].predicted_allele ==
train_df.loc[train_df.hit == 1.0].true_allele
).mean()
auc = roc_auc_score(train_df.hit.values, train_df.max_prediction.values)
print(kind, "Mean prediction for hit", mean_predictions_for_hit)
print(kind, "Mean prediction for decoy", mean_predictions_for_decoy)
print(kind, "Correct predicted allele fraction", correct_allele_fraction)
print(kind, "AUC", auc)
metric_rows.append((
kind,
mean_predictions_for_hit,
mean_predictions_for_decoy,
correct_allele_fraction,
auc,
))
update_motifs()
return (ligandome_prediction, auc)
print("Pre fitting:")
progress()
update_motifs()
print("Fitting...")
predictor.fit(
peptides=train_df.peptide.values,
labels=train_df.hit.values,
allele_encoding=allele_encoding,
progress_callback=progress,
)
(predictions, final_auc) = progress()
print("Final AUC", final_auc)
update_motifs()
motifs = pandas.DataFrame(
motifs_history,
columns=[
"allele",
"motif",
"mean_predictions_for_hit",
"mean_predictions_for_decoy",
"correct_allele_fraction",
"auc"
])
parser = argparse.ArgumentParser(usage=__doc__)
parser.add_argument(
"--out-metrics-csv",
default=None,
help="Metrics output")
parser.add_argument(
"--out-motifs-pickle",
parser.add_argument(
"--max-epochs",
default=100,
type=int,
help="Max epochs")
if __name__ == '__main__':
# If run directly from python, leave the user in a shell to explore results.
setup()
args = parser.parse_args(sys.argv[1:])
(predictor, predictions, metrics, motifs) = (
test_synthetic_allele_refinement(max_epochs=args.max_epochs))
if args.out_metrics_csv:
metrics.to_csv(args.out_metrics_csv)
if args.out_motifs_pickle:
motifs.to_pickle(args.out_motifs_pickle)
# Leave in ipython
import ipdb # pylint: disable=import-error
ipdb.set_trace()