Sec Form 4 Filing - BRATTON DOUGLAS K @ Juno Therapeutics, Inc. - 2015-06-23

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person BRATTON DOUGLAS K 2. Issuer Name and Ticker or Trading Symbol Juno Therapeutics, Inc. [ JUNO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 201 MAIN STREET, SUITE 1900 3. Date of Earliest Transaction (MM/DD/YY) 06/23/2015 (Street) FORT WORTH, TX76102 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/23/2015 J( 1 ) 825,726 D $ 0 492,669 I By JT Line Partners LP ( 2 ) Common Stock 06/23/2015 S 135,000 D $ 50.92 ( 3 ) 357,669 I By JT Line Partners LP ( 2 ) Common Stock 06/24/2015 S 135,000 D $ 51.33 ( 4 ) 222,669 I By JT Line Partners LP ( 2 ) Common Stock 25,766,130 I By CL Alaska, L.P. ( 5 ) ( 6 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other BRATTON DOUGLAS K 201 MAIN STREET, SUITE 1900 FORT WORTH, TX76102 X Signatures /s/ Douglas K. Bratton 06/25/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pro rata in-kind distribution of shares of Common Stock of Juno Therapeutics, Inc. (the "Issuer") from JT Line Partners LP ("JT") to limited partners of JT without consideration. ( 2 )The shares of the Issuer reported in Column 5 are held directly by JT. The general partner of JT is Bratton Capital Management L.P. ("Bratton Capital Management"). The general partner of Bratton Capital Management is Bratton Capital, Inc. ("Bratton Capital"). Douglas K. Bratton is the sole director of Bratton Capital. JT is ultimately controlled by Mr. Bratton and Mr. Bratton has voting and investment power over all of the shares of the Issuer held by JT, as well as a partial pecuniary interest in such shares. JT directly beneficially owns these shares of the Issuer. Bratton Capital Management, Bratton Capital and Mr. Bratton may each be deemed to indirectly beneficially own the shares of the Issuer held by JT. Each such entity and Mr. Bratton disclaim beneficial ownership of these shares, except to the extent of its or his respective pecuniary interest therein. ( 3 )The price reported in Column 4 is a weighted average price. These shares reported as sold on June 23, 2015 were sold in multiple transactions at prices ranging from a low of $50.56 per share to a high of $51.37 per share. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price set forth above and in footnote 4. ( 4 )The price reported in Column 4 is a weighted average price. The securities reported as sold on June 24, 2015 were sold in multiple transactions at prices ranging from a low of $50.65 per share to a high of $51.86 per share. ( 5 )These 25,766,130 shares of the Issuer are held directly by CL Alaska, L.P. ("CLA"). The general partner of CLA is Crestline SI (GP), L.P. ("Crestline SI") and the investment manager of CLA is Crestline Management, L.P. ("Crestline Management"). Crestline Investors, Inc. ("Crestline") is the general partner of both Crestline SI and Crestline Management. Douglas K. Bratton is the sole director of Crestline. CLA is ultimately controlled by Mr. Bratton and Mr. Bratton has voting and investment power over all of these shares of the Issuer, as well as a partial pecuniary interest in the shares held by CLA. Mr. Bratton does not intend to sell shares of the Issuer from CLA at this time, however, please see the related disclosures in Item 4 of the Schedule 13D/A filed on June 25, 2015. CLA may be deemed to directly beneficially own all of these shares of the Issuer. ( 6 )(Continued from Footnote 5) Crestline SI, Crestline Management, Crestline and Mr. Bratton may each be deemed to indirectly beneficially own all of these shares of the Issuer. Each such entity and Mr. Bratton disclaim beneficial ownership of these shares, except to the extent of its or his respective pecuniary interest therein.

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