<PAGE>   1






                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549      

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(D) OF THE
                        SECURITIES EXCHANGE ACT OF 1934


         DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED) MAY 18, 1995

                             T CELL SCIENCES, INC.
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)


         DELAWARE                       0-15006                 13-3191702
(STATE OR OTHER JURISDICTION OF      (COMMISSION FILE        (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION)            NUMBER)           IDENTIFICATION NO.)


             115 FOURTH AVENUE,  NEEDHAM, MASSACHUSETTS  02194-4135
            (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)      (ZIP CODE)

       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE  (617) 433-0771


<PAGE>   2


ITEM 5:  OTHER EVENTS

         T Cell Sciences, Inc. (the "Company") announced on May 18, 1995 that
its subsidiary, T Cell Diagnostics, Inc., received clearance from the U.S. Food
and Drug Administration to market TRAx(R) CD4 test kit. TRAx(R) CD4 test kit is
an in vitro diagnostic test kit which provides a method for enumerating CD4 T
cells, a type of white blood cell monitored by physicians treating patients
infected with HIV.  Futher details regarding this announcement are contained in
the news release dated May 18, 1995 attached as Exhibit 20 hereto and
incorporated by reference herein.


ITEM 7:       FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND
              EXHIBITS

       (c)    Exhibits

              Exhibit 99.20   T Cell Sciences, Inc. News Release dated 
                              May 18, 1995

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                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
as amended, the Registrant has duly caused this report to be filed on its
behalf by the undersigned thereunto duly authorized.


                                           T CELL SCIENCES, INC.
                                           ---------------------
                                           (Registrant)


Dated: May 23, 1995                        By:/s/ James L. Levin
                                              ------------------
                                              James L. Levin
                                              Vice President, Regulatory Affairs
                                                  and Pharmaceutical Evaluation





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                                 EXHIBIT INDEX


<TABLE>
<CAPTION>
      EXHIBIT NUMBER            EXHIBIT                   PAGE
      --------------            -------                   ----
      <S>                       <C>                       <C>
      Exhibit 99.20             T Cell Sciences, Inc.      5
                                News Release dated
                                May 18, 1995
</TABLE>






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FOR IMMEDIATE RELEASE/ May 18,1995

Alan W. Tuck               Duff Brace                Susan Primrose
President &                President &               Manager, Market Development
  Chief Executive Officer  Chief Operating Officer      & Communications
T Cell Sciences, Inc.      T Cell Diagnostics        T Cell Sciences, Inc.
(617) 433-0771             (617) 937-0890            (617) 433-0771


     T Cell Sciences' Subsidiary Receives FDA Clearance to Market TRAx(R) CD4

Needham, MA, May 18,1995 -- T Cell Sciences, Inc., (NASDAQ: TCEL), announced
today that its subsidiary T Cell Diagnostics, Inc. has received clearance from
the U.S. Food and Drug Administration to market the TRAx(R) CD4Test Kit as a
method for enumerating CD4 T cells, a specific type of white blood cell.  CD4 T
cell enumeration is the single most important clinical parameter used by
physicians to monitor disease progression and to determine proper therapy for
patients infected with HIV.

"TRAx CD4 allows more laboratories to participate in HIV patient monitoring by
providing a rapid, simple and cost-effective method of CD4 T cell enumeration,"
said Duff Brace, President and COO of T Cell Diagnostics.  "Currently CD4 T
cell enumeration is provided by approximately 500 large reference laboratories
that own an expensive and complex instrument called a flow cytometer.
 TRAx CD4
will give more than 3000 laboratories without flow cytometry equipment the
ability to offer CD4 T cell monitoring directly, saving substantial time and
expense."

Mr. Brace noted that as more individuals are diagnosed with the virus, and as
additional treatment options become available, the number of patients monitored
and the frequency of monitoring CD4 counts are likely to increase.  Recent
estimates by the World Health Organization indicate over 1.5 million HIV
infected individuals in the United States and Europe and as many as 13-15
million worldwide.

Alan Tuck, President and CEO of T Cell Sciences, commented, "TRAx CD4 is
expected to become the Company's first major revenue generating product.  TRAx
CD4 also is the first of a family of immune monitoring products based on the
Company's TRAx technology."

T Cell Diagnostics will sell the TRAx CD4 Test Kit as well as other novel
immune markers to clinical labs using its own direct sales force.  The Company
recently hired a Director of Sales and is adding regional salespeople in the
major centers where HIV infected patients are treated.  The Company expects to
have its sales and marketing efforts underway within thirty to ninety days.  T
Cell Diagnostics will utilize distribution partners for sales in Europe.

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"When compared with flow cytometry, new technologies such as TRAx CD4 hold
great promise for improving the efficiency, accuracy and reproducibility of CD4
T cell enumeration," said Alan Landay, Ph.D., Associate Professor, Department
of Immunology/ Microbiology at Rush-Presbyterian- St.Luke's in Chicago.

CD4 cell counts provide an objective measure of the immune system's
effectiveness.  As HIV infection progresses CD4 T cell counts decline.  The
National Institute of Allergy and Infectious Disease (NIAID) has established
clinical guidelines for the use of CD4 T cell counts in managing HIV infection
and in guiding drug therapy for patients.  Among these, the NIAID states that
patients with CD4 cell counts greater than 600 cells/microliter should undergo
CD4 cell enumeration every six months.  Below 600 cells/microliter it is
recommended that patients have their CD4 cell counts monitored four times a
year.  As CD4 counts approach 500 cells/microliter, patients should be
considered candidates for antiviral therapy.  Patients with CD4 cell counts at
or below 200 cells/microliter should be considered for treatment to prevent
pneumocystis carinii pneumonia, a common AIDS-associated infection.

The TRAx CD4 Test Kit is an enzyme linked immunoassay for the quantitative
measurement of CD4+ T lymphocyte equivalents in human peripheral blood
specimens.  TRAx CD4 enumerates cells through a proprietary technology that is
compatible with standard enzyme linked immunoassay (ELISA) methods, similar to
methods already used in most clinical laboratories.  The TRAx assay results are
read by a microtiter plate reader commonly found in hospitals and clinical
laboratories.

T Cell Sciences, Inc. is developing pharmaceutical products to treat diseases
of inflammation and autoimmunity utilizing proprietary complement inhibitor and
T cell receptor technology.  T Cell Diagnostics, a wholly-owned subsidiary of T
Cell Sciences, develops, manufactures and markets innovative immune monitoring
and research products.





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