CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 18, 85-94 (1981)

Spontaneous Rosetting Characteristics of Prostaglandin (PG)-Treated Lymphocytes from Patients with

Solid Neoplasias

A. MISEFARI,* D. VENZA-TETI,? G. TETI,$ M. F. LA VIA,§ AND P. F. RUST**

Institute of General Pathology, Chairs of *Immunology and TGeneral Pathology II, Slnstitute of Microbiology, University of Messina, Italy, and IDepartments of Laboratory Medicine and

**Biometry, Medical University of South Carolina, Charleston, South Carolina 29403

Received April 18, 1980

Lymphocytes forming spontaneous rosettes with mouse erythrocytes (ME) were studied in 53 patients with solid neoplasias for their sensitivity to prostaglandins (PC&) E, and F,,. While in normal subjects these PGs markedly inhibit ME-rosette formation, this inhibition is greatly reduced in cancer patients. Moreover this effect appears not to be dose dependent. These patients’ lymphocytes with high-affinity receptors for sheep erythrocytes (early E-rosette-forming cells) were also studied for their sensitivity to PGE,. In all neoplastic patients a low inhibition of early E rosettes was observed in contrast with the high values found in normal subjects. This marked increase of PG- resistant rosette-forming lymphocytes may be useful for the diagnosis and prognosis of cancer.

INTRODUCTION

Several reports from many laboratories indicate that humoral as well as cell- mediated immune responses may be modified by prostaglandins (PGs) (l-6). Plescia et al. found that PGE, has an important role in the subversion of the immune system by tumor cells and that blockage of PG synthetase inhibits the subversive activity of tumor cells (7, 8). The mechanism whereby tumor cells may subvert the host cellular immune response by the production of PGs has been confirmed (9).

We recently reported that PG treatment may be accompanied by changes in the membrane markers of lymphocytes from normal subjects. PGEz and PGF1, have a dose-dependent inhibitory effect on mouse erythrocyte (ME)-rosette-forming cells (10) which represent B lymphocytes. PGE, also inhibits in a dose-dependent fashion the rosettes which have higher affinity for sheep red blood cells (SRBC, active or early E rosettes); on the contrary late rosettes are resistant to the inhib- itory effect of PGE, (11). These rosettes represent T lymphocytes. Thus it appears that in normal subjects both ME- and E-receptor-positive human lymphocytes (T and B lymphocytes) contain well-defined PG-sensitive subpopulations (10, 11).

In the present work we present a study of the spontaneous rosetting character- istics of PG-treated lymphocytes from patients with solid neoplasias in order to ascertain whether changes in PG sensitivity of the rosetting occur during neoplas- tic disease.

85 0090-1229/81/010085-10$01.00/0 Copyright @ 1981 by Academic Press, Inc. All rights of reproduction in any form reserved.

86 MISEFAKI El AL.

MATERIALS AND METHODS

Patients. We studied 53 newly diagnosed patients with unmetastasized tumors (16 cervical carcinoma, 19 stage I breast cancer, and 18 bronchogenic carcinoma). None of these patients had previously been treated by surgery, chemotherapy, or radiotherapy. As controls we used 9 healthy volunteers, of ages comparable to the patients.

Preparation of lymphocyte suspensions. Mononuclear cells were isolated from heparinized blood on Ficoll-Hypaque density gradients (12). The cells were then washed twice with Hanks’ balanced solution without calcium and magnesium (HSBB). Phagocytic cells were labeled by incubation at 37°C for 30 min with 0.1 ml of 1% latex (Dow Chemical). Unphagocytosed latex particles were removed by centrifugation at 3008 for 5 min over fetal calf serum (FCS) absorbed with ME and SRBC (v/v). Lymphocytes were finally washed twice in HBSS and adjusted to a concentration of 1 x 107/ml.

TABLE 1 MOUSE ERY THROCYTE-ROSETTE FORMATION OF PC-TKEATED LVMPHO~Y~ES IN

PATIENTS WITH CERVK AL. CARCINOMA

Lymphocyte treatment

AS PQ NF ST LP

None 9.2 - 7.5 - 6.0 - 11.4 - 5.2 - PGE, 10-7 8.S 7.6 6.5 13.3 5.1 15.0 10.5 7.9 4.5 13.5

10-J 8.0 13.0 7.0 6.7 5.3 11.7 10.0 12.3 4.9 5.8 PGF,, 10 ’ 8.2 10.9 6.0 9.3 5.5 8.3 10.4 8.8 4.7 9.6

IO-” 8.5 7.6 6.6 12.0 4.8 20.0 10.3 9.6 4.7 9.6

FZ NL BS DF vc

None 5.5 - PGE, 10-7 5.0 9.1

10.-A 5.1 7.3 EF,” lo--’ 5.0 9.1

10-d 4.9 10.9

GD

None 9.0 - PGE, 10-T 8.5 5.5

lo- ’ 8.0 11.1 =F,.l 10-7 8.6 4.4

lo-’ 8.2 8.9

FC

7.0 - 6.0 14.3 6.5 7.1 6.3 10.0 6.1 12.8

RA

8.5 - 7.0 17.6 7.2 15.3 7.6 10.6 7.4 12.9

Controls”

10.5 - 9.6 8.6 9.3 11.4 8.6 18.1 8.8 16.2

LC

7.5 - 7.0 6.7 6.7 10.7 7.1 5.3 7.0 6.7

5.3 - 4.2 20.7 4.5 15.1 5.3 0 4.7 11.3

GL __.- ~~-

6.2 - 5.8 6.4 5.5 11.3 6.2 0 5.7 8.1

11.7 - 10.5 10.2 10.4 11.1 11.0 6.0 10.7 8.5

AD

10.0 - 8.5 15.0 8.7 13.0 9.0 10.0 8.5 15.0

None 9.5 - 7.6 + 2.2 - PC=2 10-T 8.2 13.7 4.8 + 2.0 36.8

10-q 8.4 11.6 3.7 + 1.2 51.3 PGF,, 10-7 9.0 5.3 5.6 + 1.8 26.3

10-4 8.2 13.7 3.2 + 1.0 57.9

Nofe. Under each patient, the figures in the first column are percentage MERFC and the figures in the second column are percentage inhibition.

” Mean k SD for nine normal subjects.

PROSTAGLANDINS, ROSETTES, AND CANCER 87

PG treatment of lymphocytes. Lymphocytes were incubated with PGs at 25°C for 30 min. This treatment has been shown to be optimal using lymphocytes from healthy donors (10, 11). Lymphocytes (1 x 106) to be tested for ME-rosette for- mation were treated either with PGFI, (Upjohn, Lot 11777-JHK-149A) or PGE, (Upjohn, Lot 2-PRC-3001A) at a final concentration of IO-’ or low4 M. These concentrations were chosen since previous studies had shown significant ME- rosette inhibition with these PGs at both levels (10). Lymphocytes (1 x 106) to be tested for early E-rosette formation were treated only with PGEz at 10e4 M, since higher dilutions of PGE, gave lesser inhibition values of early E rosettes (11). After incubation with PGs the lymphocytes were washed with HBSS, resus- pended, and used for rosette tests. Control, PG-free lymphocyte suspensions were processed in parallel. Almost all untreated and PG-treated cells were viable (98%) as tested by trypan blue dye exclusion.

ME-rosette test. Mouse erythrocyte rosette-forming cells (MERC) were deter- mined by the technique previously described (10). Briefly, lymphocyte suspen- sions (0.1 ml) were mixed with HBSS (0.1 ml), heat-inactivated, ME-absorbed FCS (0.2 ml) and freshly prepared, PBS-washed ME using an erythro- cyte:lymphocyte ratio of 40: 1. The mixture was centrifuged at 200s for 5 min followed by incubation at room temperature for 2 hr. The pellet was gently resus- pended and at least 200 lymphocytes were counted.

TABLE 2 EARI.Y E-ROSETTE FORMATION OF PGEz-T~n~~~~ LYMPHOCYTES IN PATIENTS

WITH CERVICAL CARCINOMA”

Lymphocyte Percentage

- treatment RFC Inhibition RFC Inhibition RFC Inhibition

(AS) (PQ) (NV None 26.5 - 24.0 - 28.2 -

PGE, 20.9 21.1 20.6 14.2 23.4 17.0

(ST) (LPI (W None 30.1 23.5 - 27.2 -

PGE, 22.6 24.9 21.6 10.2 23.9 12.1

WL) (BSl (DFl None 29.3 - 25.5 28.3 -

PGE, 23.7 19.1 20.0 21.6 21.8 23.0

(VC) (GD) (RAl None 24.5 28.8 26.0 -

PGE, 21.8 11.0 24.8 13.9 21.8 16.1

CC) (GL) (AD) None 23.5 - 31.0 21.5 -

PGEz 19.0 19.1 24.0 22.6 20.6 25.1

(FCl Controls” None 26.2 27.3 +- 2.9 -- PGEz 20.7 21.0 11.4 t 1.3 58.2

” PGE, was tested at a final concentration for IO-’ M. Subjects in parentheses. ’ Mean 5 SD for nine normal subjects.

88 MISEFARI ET AI.

Early E-rosettr test. Early rosette-forming cells (RFC) were identified by the technique of Wybran and Fudenberg (13), as previously described (11). An erythrocyte:lymphocyte ratio of 8: I and a short incubation period of the mixture (5 min at room temperature) were used to detect lymphocytes with high-affinity receptors for SRBC. In certain experiments lymphocytes were fractioned ac- cording to Wybran et al. (14) as previously reported (11) and after incubation with PGE, as above, late RFC were counted, using an erythrocyte:lymphocyte ratio of 4O:l and longer incubation at room temperature (2 hr).

TABLE 3 MOUSE ERYTHROCYTE ROSETTE FORMATION OF PC&TREATED LYMPHOCYTW WIIH BRtAu CANCER

Lymphocyte treatment

None

PGE,

PGF,,

None PGE?

PGF,,

None PGE,

PGF,,

None

PC=,

PGF,a

None

PGE,

PGF,,

AR LA

IO--'

10-a

10~ i IO-’

9.0 - 6.5 7.1 21.1 8.5 19.0 6.7 25.5 7.8 25.7 6.9 23.3 9.0 14.3 6.5 27.8 7.7 26.7

LZ RS

10-T 10-G 10-7 10-d

8.6 - 11.5 - 6.4 25.6 9.0 21.7 6.5 24.4 8.2 28.7 6.6 23.2 8.5 26.1 6.3 26.7 8.3 27.8

so BR

10-1 10-G 10-7 10-a

7.0 - 6.4 - 5.6 20.0 5.5 14.1 5.5 21.4 5.2 18.7 5.2 17.2 5.3 17.2 5.2 25.7 5.1 20.3

BF AR

10--T IO-’ 10-T IO-4

4.5 - 6.6 3.8 15.5 5.8 12.1 3.5 22.2 5.5 16.7 4.0 11.1 5.2 21.2 3.7 17.8 5.0 24.2

RB LA

FT FQ

5.3 - 8.6 - 5.2 20.0 4.3 18.9 5.5 15.4 4.0 24.5 5.4 16.9 4.2 20.7 5.4 16.9 4.0 24.5

SF FZ

8.7 - 5.5 7.2 17.2 4.8 12.7 7.0 19.5 4.6 16.4 7.5 13.8 4.8 12.7 7.6 8.7 4.5 25.7

CS AL

5.0 - 8.5 - 4.0 20.0 6.5 23.5 3.8 24.0 6.0 29.4 4.2 16.0 7.0 17.6 4.2 16.0 6.5 23.5

CF FS

11.0 - 9.5 - 9.0 18.2 8.0 15.8 8.8 20.0 7.4 22.1 9.5 13.6 7.8 17.9 8.9 19.1 7.5 21.0

NM Controls”

6.2 - 7.6 - 4.5 - 7.6 + 2.2

10-1 5.5 13.3 6.5 14.5 4.0 11.1 4.8 -t 2.0 36.8 10-d 5.1 17.7 6.0 21.0 3.7 17.8 3.7 2 1.2 51.3 10-T 5.5 13.3 6.3 17.1 4.1 8.9 5.6 2 1.8 26.3 10-4 5.0 19.3 6.2 18.4 3.8 15.5 3.2 + 1.0 57.9

Note. Under each patient, the figures in first column are percentage MERFC and the figures in the second are percentage inhibition.

n Mean f SD for nine normal subjects.

PROSTAGLANDINS, ROSETTES, AND CANCER 89

RESULTS

Cervical Carcinoma

Results of MERFC and percentage inhibition of ME-rosette formation by PGE, in 16 patients with cervical carcinoma are shown in Table 1. All patients demon- strated normal values of MERFC but preincubation of their lymphocytes with both PGs caused significantly less inhibition of ME-rosette formation than that seen in normal controls (P < 0.001 in each case). In fact the inhibition attained its maximum value (20.7%) in patient DF with PGE, at lo-’ M, while the range in the controls was 22.4-71.4% for PGE, and 16.9-69.10/o for PGF,,. In two patients (DF, GL) PGF1, at 10m7 M gave no inhibition at all.

Early E rosettes and their percentage inhibition by PGE, in the patients with cervical carcinoma are shown in Table 2. In agreement with results of Kerman et al. (15), who found normal percentage of early RFC in cancer patients, early E rosettes were seen in normal number. On the contrary the ability of PGE, to inhibit early E rosettes was significantly lower than in normal controls (P < 0.001). While percentage inhibition was 58.2% in controls, in cancer patients it

TABLE 4 EARLY E-ROSETTE FORMATION OF PGE,-TREATED LYMPHOCYTES IN PATIENTS

WITH BREAST CANCER”

Lymphocyte treatment RFC Inhibition

Percentage

RFC Inhibition RFC Inhibition

(AR) (LA) (FTl None 26.5 - 28.2 - 30.0 - PGE, 23.8 10.2 26.0 7.8 25.5 15.0

(FQ) (LZ) (RS) None 23.0 - 25.7 - 26.2 - PGE, 21.8 5.2 22.9 11.0 24.6 6.1

(SF) (FZ) (SO) None 24.5 29.2 27.5 PGE, 21.3 13.1 26.5 9.2 23.5 14.5

(BR) (CS) (AL) None 30.3 - 27.4 - 30.5 - PGE, 26.4 12.9 24.7 9.8 26.0 14.7

W) (AR) (W None 25.2 - 28.5 23.0 - PGE, 23.9 5.1 26.0 8.8 19.8 13.9

(W (RB) (LA) None 24.5 - 29.8 - 27.6 - PGE, 22.8 6.9 26.0 12.7 24.6 10.9

(NM) Controls” None 24.5 - 27.3 2 2.9 - PGE, 22.5 8.2 11.4 r 1.3 58.2

” PGE, was tested at final concentration of 1O-4 M. Subjects in parentheses. b Mean 2 SD for nine normal subjects.

90 MISEFARI t-1 41

ranged from 10.2 to 25.1%. Only in two patients it was higher than 23% (ST and AD, respectively, 24.9 and 25.1%).

Breast Cuncer

Nineteen patients with stage 1 cancer were studied. ME-rosette formation and PG-induced inhibition in these patients are shown in Table 3. Normal values 01 MERFC were observed always, but the PG-mediated inhibition was lower than in

TABLE 5 MOUSE EHYTHROCY~~ ROSETTE FORMATION OF PG-TR~A.~E.D PAIIENIS

WITH BRONCHOGENIC CARCINOMA

Lymphocyte treatment

None PGEL

PGF,<,

None PGE,

PGF,,

None PGE,

PGF,,

None PGE,

PGE,,

None PGE,

PGF,,

---.- AD GO

-.... . 11.s 8.0 -

8.0 27.8 5.8 27.5 8.5 26.1 5.5 31.2 8.4 26.9 6.0 25.0

8.2 28.1 5.7 28.1

PS BT

1.3 - 8.5

5.5 24.6 6.8 20.0 5.3 27.4 6.5 23.5

6 17.8 6.3 25.9 5.8 20.5 6.2 27.0

DL EN

4.8 - 6.5

3.5 27. I 5.5 15.4

3.6 25.0 5.0 23.1

3.8 20.0 5.2 20.0 3.5 27.1 5.2 20.0

CM BS ___-~--

6.5 5.0

5.1 21.5 4.0 20.0

5.0 23.1 3.5 30.0

5.0 23.1 3.6 28.0

4.8 26.1 2.8 24.0

BN CZ .____--.--

7.0 - 7.5 5.0 18.6 6.0 20.0 6.0 14.3 5.8 22.1 5.8 17.1 5.9 21.3 5.6 20.0 5.6 25.3

BF PL . .~-

5.2 - 4.4 IS.4

4.0 23.1

4.5 13.5

4.2 19.2

AN

6.4 - 5.0 21.9

4.8 25.0

5.2 18.7

5.0 71.Y

CD

10.7 10.5 8.5 20.6 8.0 23.8

8.0 25.2 1.5 28.6

8.5 20.6 8.5 19.0

8.2 23.4 7.4 29.5

LC AS

7.3 8.4

5.7 21.9 6.2 26.2

5.5 24.6 6.0 28.6

5.9 19.2 6.5 22.6

6.1 16.4 6.2 26.2

MD FG

9.2

7.2 21.7

6.9 25.0

7.3 20.6

7.0 23.9

Control”

6.5

5.0 23.1

4.7 27.7

5.0 23.1

4.9 24.6

1.6 5 2.2

4.8 t 2.0 36.8

3.7 t- I.2 51.3 5.6 t 1.8 26.3

3.2 t I.0 57.9

Note. Under each patient, the figures in the first column are percentage MERFC and figures in the second column are percentage inhibition.

” Mean t SD for nine normal subjects.

PROSTAGLANDINS, ROSETTES, AND CANCER 91

controls. PGFI, at 10e4 gave the lowest inhibition (8.7%) in patient SF while the greatest inhibition (29.4%) was recorded for patient AL with PGE, at 10M4 M.

Results of early E rosettes and PGE,-induced inhibition are shown in Table 4. Early RFC were in the range of healthy controls, while in cancer patients the inhibition values were considerably lower than in controls (the range being 5.1-15.0%).

Bronchogenic Carcinoma

ME-rosette formation and inhibition in 18 patients with bronchogenic car- cinoma are shown in Table 5. In these patients also, the percentage of MERFC was normal and the PG-induced inhibition was lower than in controls (range: 13.5-31.2%). Patient BF, at lo-’ M, had inhibitions of 15.4% with PGE, and 13.5% with PGF1,. Only two patients (BS and GO) showed inhibition greater than 29.5% with PGE, 10m4 M.

As shown in Table 6 all patients with bronchogenic carcinoma demonstrated normal percentage values of early RFC. Lymphocyte treatment with PGE2 re-

TABLE 6 EARLY E-ROSETTE FORMATION OF PGEZ-TREATED LYMPHOCYTES IN

PATIENTS WITH BRONCOGENK CAIKINOMA”

Lymphocyte treatment RFC Inhibition

Percentage

RFC Inhibition RFC Inhibition

None PGE,

None PGE,

None PGE,

None PGE,

None PGE:!

None PGE,

None PGE,

(AD) 26.5 22.5 15.1

(PL) 28.6 - 22.9 19.9

(ANI 30.1 - 25.9 13.9

(EN 26.7 21.4 19.8

(CM) 23.5 19.3 17.9

(FG) 25.5 - 22.7 11.0

Controls* 27.3 2 2.9 - 11.4 k 1.3 58.2

23.0 19.0

25.2 22.4

27.0 23.5

28.0 23.8

30.0 25.2

28.2 24.0

(GO) -

17.4

(l-3) -

11.1

(CD) -.

13.0

(LC) -

15.0

(BS) -.

16.0

(BN) -.

15.0

31.4 27.6

26.3 27.1

24.5 20.5

29.7 26.1

27.2 22.0

24.6 21.1

(BF) -

12.1

(BT) -

16.0

(DL) -

16.3

(AS) -

12.1

(MD)

19. I

(CZ) -

14.2

” PGE, was tested at a final concentration of 10m4 M. Subjects in parentheses. b Mean k SD for nine normal subjects.

92 MISEFARI El Al.

sulted in inhibition values ranging from 11 .O to 19.9% and thus considerably lower than the mean inhibition seen in controls (58.2%).

For comparison purposes the individual values observed in the nine controls are reflected in Table 7. Statistical analyses were applied to the percentage inhibition values in patients and in controls. Since the inhibition values are not necessarily normally distributed. the two-sample Wilcoxon test was used in all comparisons (16). Table 8 summarizes the outcomes for cervical, breast, and bronchogenic carcinomas, taking the conservative policy of reporting two-tailed tests. Even so. the reduced inhibition of both ME- and early E-rosette formation, with only one exception, is strongly evident.

TABLE 7 ROSETTE FORMATION IN CONTROI.S: AI-I. TRtArMEN rs

Lymphocyte treatment

None PGE,

PGF,

None PGE,

PGF,

None PGE,

PGF,

None PGE,

None PGE,

None PGE,

10~ 7 10 ’ 10 7 10 ’

10 i IO ’ 10 i IO ’

10 i 10-l 10~ i 10 4

(Early Et

(Early E)

(Early E)

AL .-.____

7.1 3.9 45.1 3.5 50.7 5.9 16.9 2.x 60.6

ML

9.8 7.6 22.4 4.2 57.1 6.7 31.6 3.5 64.4

GM

7.6 - 4.8 36.8 3.7 51.3 5.2 31.6 2.7 64.5

AL

j3.5 13.2 60.6

ML

30.1 - 12.4 58.8

GM

GT DF ..---.-. --~~~~~~~

4.2 10.5 2.1 50.0 5.6 46.7 1.2 71.4 4.2 60.0 3.1 26.2 8.3 21.0 2.0 52.4 3.8 63.X

RT DB

9.7 4.7 6.4 34.0 I.5 68.1 -4.0 58.8 2.9 38.3 7.2 25.8 3.0 36.2 3.0 69.1 '.I 55.3

TS OD

8.3 6.5 - 6.3 24.1 4.8 26.2 5.9 28.9 3.8 41.5 6.9 16.9 4.5 30.8 4.7 43.4 4.6 29.2

GT DF __.__~~~~~~~..

23.2 26.6 9.4 59.5 I I.2 57.9

RT DB

26.5 25.4 11.8 55.5 10.7 57.9

TS OD

26.3 27.4 - 26.5 10.8 58.9 13.2 51.8 10.2 61.5

Now. Under each patient the figures in the first column are percentage MERFC or ERFC and the figures in the second column are percentage inhibition.

PROSTAGLANDINS, ROSETTES, AND CANCER 93

TABLE 8 TWO-SIDED WILCOXON COMPARISONS ON PERCENTAGE INHIBITION OF

ROSETTE FORMATION: PATIENTS vs NINE CONTROLS

Carcinoma types

Lymphocyte treatment

Cervical (n = 16)

Breast (n -= 19)

Bronchogenic (n = 18)

PGEL

PGF,,,

PGE,

10-7 10-q 10-7 IOF

(Early E)

(/ = o*** " =3*x* ,y zz lfj*** /J = o*** ” = 1*** ” = 2*** (/ = 2*** lJ = 28** u = 47* /-J = f-J*** 0 = ()*@* (/ = 1*** I/ = o*** (J = o*** c/ = I)***

* p < 0.10: ** P < 0.01: *** P < 0.001

DISCUSSION

Experiments reported previously (10, 11) and confirmed here demonstrate that both MERFC and early RFC of healthy subjects are greatly affected, in a dose- dependent fashion, by PGE,. ME-rosette formation is also modified by PGF,,. The depression observed in these experiments is induced by concentrations of PGs which are in the range of those capable of depressing the response of lymphocytes to mitogen stimulation. The current work indicates that the lowest PG-mediated inhibition of ME-rosette formation has been observed in patients with cervical car- cinoma and the lowest inhibition of early E rosette in patients with stage I breast cancer. However, it must be pointed out that in cancer patients the inhibition values of either ME or early E rosettes were never comparable with those ob- served using lymphocytes from normal subjects. With early E rosettes the inhibi- tion was very significantly higher in all instances (P < 0.001).

In normal subjects PGE, affects only early E rosettes, with late RFC not af- fected at all (11). In preliminary experiments it appeared that also in cancer pa- tients late RFC seemed to constitute a PG-resistant cell population. In addition, the data reported here indicate that during neoplastic disease the PG-resistant sub- population increases remarkably as tested by the PG-induced inhibition of ME- and early E-rosette formation. Moreover, in normal subjects the PG-mediated inhibition of rosette formation appears to be dose-dependent and the inhibition was always higher employing a PG concentration of 10e4 M. On the contrary, this dose-dependent effect was not constantly found using lymphocytes from cancer patients. In fact, in many instances the inhibition of ME rosettes was higher at PG concentration of 10e7 M, a dose capable of suppressing mitogen responses and in the range of naturally occurring PGs (4).

The reduction of PG sensitivity in cancer patients appears to be quite interest- ing, particularly in view of the fact that all patients tested showed normal per- centages of either MERFC or early RFC. The latter observation is in agreement with the results of others (15, 17), although some authors (13) reported lower than normal percentages of early RFC in patients with solid tumors. In any case it seems likely that the PG-induced inhibition of spontaneous rosettes may result

from some modification in the immunological competence of lymphocytes in cancer patients.

The present studies do not indicate the in \~ivo significance of the marked in- crease of PG-resistant lymphocyte subpopulations during neoplastic diseases. Future studies will be directed to further elucidation of this phenomenon. In the meantime, the study of PG sensitivity of lymphocytes may represent a useful test for following patients with neoplastic diseases.

ACKNOWLEDGMENTS

The authors wish to thank Dr. John Pike (Upjohn Company, Kalamazoo, Mich.) for the generous gift of prostaglandins. This work was supported in part by a grant from the Scientific Committee of the Smokeless Tobacco Council. G. Teti is a visiting scientist supported by Special Project No. 99 of the Council for Tobacco Research-U.S.A.. Inc.. and by a travel award of the Lega Italiana per la Lotta contra i Tumori.

REFERENCES

1. Pelus. L. M.. and Strausser. H. R.. Lije Sri. 20. 903, 1977. 2. Gordon, D.. Bray, M. A.. and Morley, J.. Nuiurr (Londort) 262, 401. 1976. 3. Lomnitzer, R.. Rabson, A. R.. and Koornhof. H. J., C/in. Exp. Immunol. 24, 42. 1976. 4. Goodwin. J. S., Bankhurst, A. D., and Messner. R. P., J. Exp. Med. 146, 1719, 1977. 5. Droller, M. J.. Perlmann. P.. and Schneider. M. U., Cell. Immunol. 39, 154, 1978. 6. Droller, M. J.. Schneider. M. U., and Perlmann, P.. Cell Immunol. 39. 165. 1978. 7. Plescia. 0. J., Smith. A. H.. and Grinwich. K., Proc,. Nut. Acud Sci. USA 72, 1848, 1975. 8. Plescia, 0. J.. Grinwich, K., and Plescia, A. M.. Ann. N.Y. Acud. Sci. 276, 455, 1976. 9. Droller. M. J.. Lindgren. J. A., Laessen, H. E.. and Perlmann, P. Cell. Immunol. 42, 261. 1979.

JO. Misefari, A.. Venza-Teti, D.. and La Via, M. F.. Immunophurmucolog~ 2, 109. 1980. 11. Venza-Teti, D., Misefari, A.. Sofo, V.. Fimiani, V.. and La Via, M. F., ~rnrnu~u~~urrnu~~~~u~~

2, 165, 1980. 12. Boyum. A.. Scund. J. Clin. Invrst. 21 (Suppl. 97). 77, 1968. 13. Wybran, J., and Fudenberg. H. H.. J. C/in. fntvst. 52, 1926. 1973. 14. Wybran, J.. Chantler. S., and Fudenberg, H. H.. J. Immunol. 110, 1157. 1973. 15. Kerman, R. H., Smith, R.. Stefani, S. S.. and Exdinli, E. A.. Cancer Res. 36, 3247. 1976. 16. Conover, W. J.. “Practical Nonparametric Statistics.” Wiley. New York, 1971. 17. Goust, J. M.. Roof. B. S., Fudenberg. H. H.. and O’Brien. P. H.. Clin. fmmunol. Immunoputhol.

12, 396, 1979.