Methods of detection and removal of rhabdoviruses from cell lines
The present disclosure relates to compositions, methods, mixtures, and kits for detecting the presence of, and for removing, a virus from a product produced in an insect cell. The disclosure also relates to proteins, peptides, polypeptides, drug substances, biological products, vaccine antigens, and virus-like particles that are produced in an insect cell and that are free or substantially free of a virus. The disclosure also relates to compositions, methods, assays, and kits for detecting a rhabdovirus in a sample.
1 . A kit for detecting a target nucleic acid sequence within a sample, wherein the target nucleic acid sequence comprises at least 50 contiguous nucleotides of SEQ ID NO: 1 or the reverse complement of SEQ ID NO: 1, wherein the kit comprises one or more primers and at least one probe that is labeled with a fluorophore.
2 . The kit of claim 1 , wherein the one or more primers comprise a forward primer and a reverse primer.
3 . The kit of claim 2 , wherein the nucleotide sequence of the forward primer is SEQ ID NO: 2 and the nucleotide sequence of the reverse primer is SEQ ID NO: 3.
4 . The kit of claim 1 , wherein the fluorophore is fluorescein or a fluorescein derivative or is selected from the list consisting of: 6-carboxy fluorescein (FAM), VIC, JOE, 5-(2′-aminoethyl) aminonaphthalene-1-sulphonic acid, coumarin and coumarin derivatives, lucifer yellow, texas red, tetramethylrhodamine, 6-Carboxy Fluorescein, tetrachloro-6-carboxyfluoroscein, 5-carboxyrhodamine, and cyanine dyes.
5 . The kit of claim 1 , wherein the fluorophore is 6-carboxy fluorescein (FAM).
6 . The kit of claim 1 , wherein at least one of the probes is complementary to a portion of SEQ ID NO: 1 or the reverse complement of SEQ ID NO: 1.
7 . The kit of claim 1 , wherein the nucleotide sequence of at least one of the probes is SEQ ID NO: 4.
8 . The kit of claim 1 , wherein the kit has a detection sensitivity level of between about 2 molecules of RNA and about 20 molecules of RNA.
9 . The kit of claim 1 , wherein the kit includes instructions for detection of the target nucleic acid sequence via RT-PCR.
10 . The kit of claim 1 , wherein the kit is for determining if the target nucleic acid sequence is present in a particle and/or aggregate in the sample.
11 . The kit of claim 10 , wherein the kit comprises an RNase.
12 . The kit of claim 11 , wherein the RNase is RNase A.
13 . The kit of claim 10 , wherein the kit comprises a chaotropic agent.
14 . The kit of claim 10 , wherein the kit includes instructions to:
i) treat the sample with an RNase;
ii) inactivate the RNase and disrupt any particles in the sample with a chaotropic agent; and
iii) use RT-PCR to detect RNA corresponding to the target nucleic acid sequence,
wherein the presence of RNA corresponding to the target nucleic acid sequence in the RNase-treated sample indicates that the RNA corresponding to the target nucleic acid sequence is present in a particle and/or aggregate in the sample.
15 . The kit of claim 1 , wherein the kit is for determining if the target nucleic acid sequence in the sample is comprised by a virus capable of replication.
16 . The kit of claim 15 , wherein the kit comprises a cell line permissive of Sf9 rhabdovirus replication.
17 . The kit of claim 16 , wherein the cell line is a Spodoptera exigua cell line.
18 . The kit of claim 17 , wherein the kit includes instructions to incubate the sample with a Spodoptera exigua cell line; passage the cell line one or more times following incubation with the sample; and detect the presence or absence of the target nucleic acid sequence at the following time-points: after incubating the cell line with the sample and after each passage of the cell line, wherein an increase in the level of RNA corresponding to the target nucleic acid sequence after at least one of the one or more passages relative to the level of RNA corresponding to the target nucleic acid sequence detected immediately after incubation of the cell line with the sample indicates that the target nucleic acid sequence is present in the sample and is comprised by a virus capable of replication.
19 . The kit of claim 17 , wherein the kit includes instructions to:
(i) treat the sample with an RNase;
(ii) inactivate the RNase and disrupt any particles in the sample;
(iii) detect the presence or absence of RNA corresponding to the target nucleic acid sequence in the RNase treated sample by RT-PCR;
(iv) incubate the RNase-treated sample with a Spodoptera exigua cell line;
(v) passage the Spodoptera exigua cell line at least once;
(vi) purify total RNA from the cell line at the following time points: after incubation with the RNase treated sample, and after each of the at least one cell passages; and
(vii) detect RNA corresponding to the target nucleic acid sequence in the total RNA from each time point by RT-PCR;
wherein an increase in the level of RNA corresponding to the target nucleic acid sequence detected after at least one passage relative to the level of RNA corresponding to the target nucleic acid sequence detected immediately following incubation of the Spodoptera exigua cell line with the RNase-treated sample indicates that the RNA corresponding to the target nucleic acid sequence is present in the sample and is comprised by a virus capable of replication.
20 . The kit of claim 1 , wherein the sample comprises an Sf9 cell, an Sf21 cell, a cell derived from the cell line deposited as ATCC CRL-1711, or a cell passaged from an Sf9 cell, an Sf21 cell, or a cell derived from the cell line deposited as ATCC CRL-1711.
21 . The kit of claim 1 , wherein the sample comprises a biological product.
22 . The kit of claim 21 , wherein the biological product is for therapeutic and/or diagnostic purposes.
23 . The kit of claim 21 , wherein the biological product is generated in an insect cell.
24 . The kit of claim 23 , wherein the insect cell is an Sf9 cell, an Sf21 cell, a cell derived from the cell line deposited as ATCC CRL-1711, or a cell passaged from an Sf9 cell, an Sf21 cell, or a cell derived from the cell line deposited as ATCC CRL-1711.
25 . The kit of claim 21 , wherein the biological product comprises a protein, peptide, drug substance, antibody, enzyme, growth factor, polysaccharide, nucleic acid, vaccine antigen, virus, or virus-like particle (VLP).
26 . The kit of claim 25 , wherein:
i) the nucleic acid is DNA or RNA;
ii) the virus is a recombinant virus for gene therapy;
iii) the antibody is a monoclonal antibody;
iv) the VLP is a Calicivirus or Norovirus VLP; or
v) the protein is a therapeutic protein.
27 . The kit of claim 25 , wherein the sample is a drug substance, and the kit is for use in a release assay for the drug substance.